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Influence of Oil Products on Mechanical Properties of Polymer Concrete

By: Mustafa Hasan Omar Al-Karkhi   Supervised By: Asst. Prof. Dr. Sanaa A. Hafid   year: 2014

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In the present work different variables were used, such as styrene butadiene rubber SBR, poly vinyl acetate PVAc and wood ash as a partial replacement by weight of cement. Unsaturated polyester resin used as a binder with aggregate instead of cement to form polymer concrete (PC) and as a coating for plain concrete. All types of specimens were immersed in oil products (gasoline, gas oil and kerosene) for 3 months after 28 days water curing and then the results compared with reference concrete which left in air for the same period. The mechanical properties of these concretes were examined in compressive strength test, splitting tensile strength test, ultrasonic pulse velocity test and Schmidt hammer test. The test results of concrete continuously immersed in oil products indicate that the mechanical properties are decreased as the time period increase. The reduction in compressive strength of specimens which immersed 90 days in gas oil, kerosene and gasoline respectively for wood ash concrete is 13.04%, 56.52%, and 43.47%. For PVAc concrete is 11.11%, 27.77% and 5.55%. For SBR concrete is 33.33%, 44.4% and 33.33%. For polyester resin concrete is 26.31%, 44.73% and 13.15% and for coated concrete is 48%, 44% and 36%. While the reduction in splitting tensile strength of specimens after 90 days of soaking in gas oil, kerosene and gasoline respectively for wood ash concrete is 17.48%, 9.62% and 0%, for PVAc 7.45%, 22.9% and 23.6%. For SBR concrete is 22.9%, 23.6% and 23.6%. For polyester resin concrete it is 9.62%, 0% and 8.25% and for coated concrete is 15.09%, 23.6% and 16.36%. The results also show that the reduction in UPV of specimens which immersed 90 days in gas oil, kerosene and gasoline respectively for wood ash concrete is 14.33%, 18.15% and 21.9%. For PVAc concrete is 15.67%, 1.56% and 11.19%. For SBR concrete is 0%, 11.04% and 5.66%. For polyester resin concrete is 8.92%, 16.35% and 16.13% and for coated concrete is 13.14%, 47.01% and 18.46%. The reduction in Schmidt rebound hammer of specimens after 90 days of soaking in gas oil, kerosene and gasoline respectively for wood ash is 35.71%, 42.85% and 42.85%, for PVAc 38.46%, 38.46% and 38.46%. For SBR concrete is 33.33%, 33.33% and 33.33%. For polyester resin concrete is 47.61%, 42.85% and 59.52% and for coated concrete is 44.44%, 55.55% and 55.55%. Polymer concrete gives a higher compressive strength compared with reference concrete by about 84% and that was due to the morphology which illustrated by SEM test.

Carbonizing and Aluminizing of carbon steel and measuring the corrosion resistance in corrosive media

By: Mays Jabbar Ne’ma    Supervised By: Asst.Prof.Dr. Mohammed S.Waheed   year: 2014

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In this research a diffusion coating process was conducted, which includes carbonizing process (using carbon powder) and the process of aluminizing (using aluminum powder with a purity 99.9 %) in a process of pack cementation. This method is characterized by modernity, availability of the requirement and ease of application. Three kinds of carbon steel family (low carbon steel, medium carbon steel and high carbon steel) have been selected, including a variation in the carbon-content to see the response of these alloys to coating process and the effect of the carbon-content on coating diffusion layer. Coating process has been applied at different temperatures (910 and 820°C) for each of the low carbon steel and medium carbon steel respectively in the carbonizing process and (900°C) for each of the medium carbon steel and high carbon steel in the aluminizing process and at different periods of time including (1, 4 and 6 hours) for the carbonizing process and (1, 2 and 4 hours) for the aluminizing process, then studying the mechanical and corrosion properties. Through the examination of the coating layer thickness using an ( optical microscope device) showed that the best deposition and higher thickness of coating layer obtained in low carbon steel alloy(the measure of thickness of precipitated coating layer for low carbon was 52.1 µm(in one hour), 75 µm (in four hours) and 118.5 µm (in six hours) ). While in medium and high carbon steel the thickness of the coating layer formed is low in the first time intervals ( for medium carbon in carbonizing process was 44 µm (in one hour), 61.3 µm (in four hours) and 98.2 µm (in six hours), in aluminizing process it was 62.06 µm (in one hour) , 66.53 µm (in two hours) and 74.16µm (in four hours) ) , for high carbon steel the thickness was (37.2µm (in one hour),43.9 µm (in two hours) and 55.8 µm (in four hours) ). XRD results showed for coated samples that the coating layer to be a mixture of phases group will enhance the hardness, mechanical characteristics and corrosion resistance. It also showed (low, medium and high carbon steel) that there is a clear improvement in the wear rate due to the emergence of solid phases(created after heat treatment) within the grounds of those alloys contributed significantly in increasing the surface hardness values and thus high wear resistance. The varied of decreasing proportion of wear rate among alloys depended on the thickness of the coating layer associated with increasing the period of time for deposition and carbon-content of the alloy. Microhardness testing showed a gradual decrease in the values of hardness towards the core resulted from emergence of crust surrounding containing (inter metallic compounds) which increases the surface hardness; however the sample core is soft, which is not affected by coating process. The corrosion test results showed an improvement in the corrosion resistance of coated samples and corrosion current (Icorr) values vary according to the thickness of coating layer.

Study of Some Thermal and Mechanical Properties of (EP-PVC) Blends and Their Composites in Different Aqueous Mediums

By: Nada Rasheed Kareem Kammona    Supervised By: Dr. Awham M. Hameed   year: 2014

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In this study a binary polymer blend was prepared and characterized by hand lay-up method. (Epoxy/polyvinyl chloride, EP/PVC) blends were prepared with different weight ratios of (0, 5, 10, 15 and 20) % of (PVC). The influence of addition of (PVC) on the mechanical properties of epoxy resin (type Quickmast 105) was examined.Based on the homogeneity, miscibility and the higher impact strength, the ratio(80/20%) was selected as the best percentage and then this blend was reinforced with polypropylene, carbon fibers and hybrid of both types with fiber volume fraction (30%). Differential Scanning Colarimeter test (DSC) was performed to determine the values of glass transition temperature (Tg) for the material under study, the results of this study show that the hybrid composite has the higher value of (Tg) compared with other materials. Thermo gravimetric analysis (TGA)was carried out to investigate the relation between the weight losses of sample with increase of temperature, it was found that the weight loss of epoxy resin decreases after blending with (PVC) and reinforcing the blend with fibers mentioned above. Thermal conductivity test illustrated that studied materials have good thermal insulation as well as the hybrid composite has the minimum value of thermal conductivity coefficient. The microstructure and impact fracture surfaces of the blends and their composites were investigated by using scanning electron microscope (SEM). The experimental results show that the mixing ratio of 20% (PVC) has the highest impact strength compared with other ratios. The percentage (80/20) % of (EP/PVC) reinforced with carbon fibers records the highest values for both impact strength (I.S) and Young's modulus (E) while the hybrid composite has higher Shore D hardness compared with other composites prepared from the same blend. After studying the mechanical properties (impact, hardness and bending) of immersed specimens in different types of water include (rain, distilled and tap water) for more than two months in sealed glass containers, it was observed these types of water have negative effect on the properties in different degrees depending on the absorption rate and diffusivity of water into the prepared materials, the values of water diffusion coefficients ranged within the order (10-12m2/s).

Preparation polymer blend for Natural and synthetic Material and Study properties for Medical Uses

By: Ja'afr Husain Koaer    Supervised By: Dr. Buthaina A .I. and Dr. Nahida J.H   year: 2013

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The project is aimed at preparing poly vinyl alcohol (PVA) hydrogel by physical techniques using freeze/thaw method and by chemical method via the addition of cross link factors of Glutaraldehyde (GLT) and Boric Acid (BA) of different percentage . Specimen are prepared as plate , film and rods .In addition , polymer blends of chitosamene chloride (CsmCl) and poly vinyl alcohol are prepared at different percentage and shapes (films, plate and cylindrical rod) . more Further , physical ,structural and morphological properties of all prepared specimens are studied aimed at the possibility of their application in the medical field . Through investigating the swelling behavior for the prepared specimens , it is found that swelling percentage depends on cross linking percentage , whether physical or chemical . The result of swelling percentage when (PVA) plates are immersed in distilled water and pure have added cross linking factor (1%,3%) of (GLT) and (0.5%) of (BA) , it is observed that all specimens possess big increase of absorption during the first five hours , then stabilized words after at specific percentage .On submerging in acid (PVA) samples retained swelling percentage similar to those samples submerged in distilled water . However, (BA)and (GLT) samples ,their swilling percentage drops. On hydrogel preparation , all cycles have equal effect , except for the (8hr) freeze/thaw cycles , as they are semisolid, and when immersed on water they are dissolved .The water absorption for all specimens during the first (48hr) indicate high range of absorption , and after (96hr) , all specimens realized constant swelling percentage about (215%).The rapid swelling during the first hours are attributed to disentanglement of chains that are not involved in cross linking . The freeze / thaw process leads to physical cross linking of polymers chains. On this basis ,(15hr) freeze /thaw of (16)cycles for plate are adopted . After freeze /thaw process of samples , their water absorption percentage increases for the 1% (GLT) and 0.5% (BA) samples while the percentage decreased for the 3%GLT. The water absorption percentage in the base environment are higher than in the acid environment for the (GLT) samples. As to the calculation of weight drop percentage with time for cylindrical samples , it is found that all samples have weight stabilization after (92hr) and have identical behavior .it is noticed that are some discrepancies in the results of swelling percentage between rod and plate. The FTIR spectra for all samples before and after blending and treatment are found to appear and disappear besides band shift at different location; this is attributed to changes in conformation. The spectral intensity decreases with increasing (CsmCl) percentage explained in view of when two polymers or more are blended , changes occur in the characteristic spectra as a result of reflection in the blend that are prepared by physical mixing and chemical reaction . X-ray test results show that crystallographic thickness value for (PVA) decreases with addition of cross linking agents and depend on type and concentration of those agents. When specimens undergo freeze/thaw process the results have indicted decrease in the value of crystallographic thickness and increase in spectral intensity percentage. These results verify that polymer chain cross link, whether physical or chemical , tends to hinder crystal growth and the freeze/thaw process leads to microcrystalization . The (CsmCl) x-ray spectra result which is used as a medical material to enhance cartilage material in human body, show very high crystallization percentage and crystal structure is affected by the freeze/thaw process in addition to blend percentage with (PVA). The value of stress at failure increases with increasing (PVA) percentage. The addition of cross linking agents leads to increase in stress and depend on the concentration of these agents. It is found that addition small amounts of cross link agents leads to a reversible process as it hinders chain bonding and is not sufficient to cause cross linking of chains . These results are in full agreement with swelling percentage results. Finally, all samples have undergone optical microscope testing, from which it is concluded that air bubbles and pores are present and the shape and state of chitosamine chloride crystals are influenced by blend percentages with (PVA), and the result of density measurement of cylindrical shape samples verify the microscope test result indicating presence of bubbles and pores.

Study The Effect of Coupling Agents on The Physical Properties of Polymer Composite Materials

By: Hassan Talal Jaafar Abd Al-Hassan Alkadimey   Supervised By: Prof. Dr. Balkees M. D. Al-Dabbagh   year: 2013

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In this research , study the effect of coupling agents on the mechanical and physical properties of polymer-matrix composite was carried out. Epoxy resin type (Polyprime-EP) was used as a matrix and reinforced by (E-glass) fibers with volume fraction (ϕf = 20%). Four types of coupling agents were used in this research included (PVA-Polyvinylalchohol) , (Lg-Lignin) , (FS-Fumed-Silica NanoParticles), (TMS-Tetramethylsilane). The mechanical and physical tests were performed on these materials before the addition of these coupling agents and after it. The results showed that all the properties were better after addition the coupling agents comparing with the case before it, because of its effect on the interface of composite. The material which contains (PVA) has showed higher impact strength valued (108.7 kJ/m2); higher value of tensile strength (103.05MPa) and lower value of thermal conductivity (0.4025 W/m.K) at Lap conditions. The same material gave higher value of tensile strength and lower value of thermal conductivity after the immersion into chemical solutions (HNO3 and H2O) for (8 Weeks). While the material which contains (TMS) has showed higher bending strength valued (863.66 MPa) ; higher value of shear stress (39.98 MPa) ; higher value of Shore hardness (82.2) and higher value of young's modulus (29.02*108 MPa) ) at Lap. Conditions. The same material gave higher value of hardness and higher value of young's modulus after the immersion into chemical solutions (HNO3 and H2O) for (8 Weeks). The material which contains (Lg) has showed lower surface roughness valued (0.362 µm) at Lap Conditions. The same material gave lower surface roughness after the immersion into chemical solutions (HNO3 and H2O) for (8 Weeks). The material which contains (FS) has showed higher value of impact strength after the immersion into chemical solutions (HNO3 and H2O) for (8 Weeks). The same material that contains (TMS) has showed lower value of diffusion coefficient after the immersion for (8 Weeks) into chemical solutions Water (H2O) and dilute nitric acid (HNO3) with different normality concentrations (0.1N , 0.2N and 0.3N). The material which was the most affected by chemical solutions compring with other composite materials is the material without coupling agent (Pure GF), while the material which contains coupling agents (Lg-Lignin) was the most affected by a chemical solutions among all composite materials which contains coupling agents.

Slope Plate Casting of Al-Mg Alloy

By: Zainab Kassim Hassan    Supervised By: Dr. Awfa Abdull-Rasoul   year: 2013

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The present work encompasses the development of microstructure by using cooling plate casting process. This process consists in pouring the molten metal at temperature close to the liquid line in an inclined cooling plate. The mould and the slope plate unit were manufactured by researcher. The following variables have been used in this work: pouring temperatures of (750,800,850ᵒC), tilt angles of (30ᵒ, 40ᵒ, 50ᵒand 60ᵒ), and Mg additive of (1.6%, 0.46%) with constant cooling length (380mm). After the melt flow down cooling plate, the molten becomes semi-solid slurry at the end of the plate. This slurry fills the mould. Then these rheocast alloys are sectioned according to desired test. The optical microstructure investigations show that, the pouring temperature and tilt angle affect the grain size. Grain size decrease with decreasing of tilt angles and with decrease pouring temperature of Al-Mg microstructure. The decrease in grain size are (78µm-90µm-80µm-100µm)at (30ᵒ, 40ᵒ ) (1.6%-750,800ᵒC),for( 50ᵒ) are(61µm,78µm)for(750,800ᵒC) while at ( 1.6%,850ᵒC) for(30ᵒ, 40ᵒ, 50ᵒ ) are(71µm,127µm,110µm),for 0.46%((30ᵒ, 40ᵒ,50)(750,800,850ᵒC)are(63µm,82µm,90µm,92µm,95µm,162µm),while at (850ᵒC,0.46%,60ᵒ) are(95µm), the result of microstructure shows that the dendrite structure will change to a semi globular with longitudinal shape at different used pouring temperatures of (750,800.850ᵒC). The effect of different tilt angles of (30ᵒ, 40ᵒ, 50ᵒ) was more than in (60ᵒ) for each (1.6%Mg and0.46%of Mg) addition. Tensile results reveal that (750,800 and 850ᵒC) especially for (30ᵒ, 40ᵒ, 50ᵒ) for 0.46%-Mg(110.4,111.5 for 750ᵒC,102.2,60.9,111 for 800ᵒC)but for 850ᵒC at (30ᵒ, 50ᵒ, 60ᵒ ) have (126.7,87.4,92.3) and 1.6%Mg (30ᵒ, 40ᵒ, 50ᵒ) at 750ᵒC have a high value(120,81.6,81.5),at 800ᵒC for(30ᵒ,50ᵒ,60ᵒ)have(91.2,126.5,87.6),at850ᵒCfor(30ᵒ,40ᵒ,0ᵒ)have(65.3,78.2,101.6). Vickers macro hardness has a gradually increasing value for Al-1%Mg(750,800and850ᵒC)at(30ᵒ,40ᵒ,50ᵒ,60ᵒ)have(46,51,54,64)(44,42,51,79)(49,49,48,60), but for Al-5%Mg rheocast alloy it has a fluctuated value at750ᵒCfor(30ᵒ,40ᵒ,50ᵒ) have(52.9,60,72.1)while at 60ᵒ (47),at800ᵒCfor(30ᵒ, 40ᵒ, 60ᵒ)have(60,65.6,72.5),at 850ᵒC for(30ᵒ, 40ᵒ)have(47.5,58)and small value for high angle (50ᵒ,60ᵒ)have(44.3,44.2). X-Ray diffractography for both Al-Mg alloys shows the appearance of intermetalic compounds and different phases of (Al3 Mg2 ,α Al, δAl2O3, Mg O),while SEM picture shows a semi globular structure at different pouring temperature.

Durability Characteristics of Concrete and Reinforcing Bars Exposed to Aggressive Environments

By: Farah Hamed Rashed    Supervised By: Assist.Prof. Dr .SANAA ABDUL HADI HAFAD   year:2013

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Saline pollution attack is an important factor that lead to the deterioration of the concrete, especially in industrial plants, and has numerous studies to determine the effect of saline pollution on the properties of concrete, in order to improve the resistance of concrete to salt solutions. Although there are many research on the use of different types of chemical additives and mineral production Concrete resistance to salt solution . In spite of research address the sustainability of concrete and particularly Steel rebar submeserged in it. Steel rebar is the most important causal factors the deterioration in the reinforced concrete. The main aim of this study is to effect of additives added to reduce superior degree water and two types of mineral additives that include silica fumes and steel fiber, as well as the combined effect of these additives on the properties of concrete. The experimental work of this measure include concrete specimens have been partially submerged in a solution of chlorides and sulfates in concentrations similar to those found in aggressive conditions. The properties of concrete specimens were evaluated through the slump flow tests. The properties investigated included weight and weight changes test, Bulk Density, total absorption, ultrasound plus velocity, compressive strength electrochemical potential for various types of mixes. Three mixtures are were used in this study: Reference (RF) ,( SF -SP) content mixed with 10% of silica partial compensation of the weight of cement and 3% by weight of cement of high range water reducing agent and (STF) mix content at 0.5% of the steel fiber, to investigates the influence surface coating protection on durability properties of concrete be done mix reference coated with natural rubber( RFCNR), and mix container on 0.5% of steel fiber coated with natural rubber (STFCNR). The electrochemical tests included monitoring the electrode potential and corrosion rates using the rates of rust ,by using Tafel plots for four specimens of rebar metals. two of them were coated and submerged in two media, one of tap water and the other is salt solution . The result coated specimens has shown resistance to corrosion greater than specimens without coated when immersion in salt solution. Thus group (RFCNR ) in the most developed in all properties as compared with all other mixture immersed in salt solution for 150 days at odds with group ( SF-SP) which had development in all properties as compared with the reference mixture at 180 days of immersion in salt solution .

Study of dyes effect in optical and Electrical Properties of Polystyrene (PS)

By: Karrar Mohammed Ali    Supervised By: Dr. Nahida J.H   year: 2013

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The present work was carried out in two stages The first stage work was concerned with study of the type and ratio(%) of the dye(Methyl Orange, Methyl Blue, Methyl Red) effect on the optical properties of poly styrene(PS), the second stage select the best type and ratio ,and preparing hybrid composite(Methyl Orange/ Methyl Blue/ poly styrene),and (Methyl Orange/ Methyl Red / poly styrene) to study its optical, and electrical properties . The samples were casted as films from the homopolymer(PS) above stated and the Dye/ poly styrene (Methyl Orange / poly styrene, Methyl Blue / poly styrene,and Methyl Red / poly styrene )composites at (3.44,6.7,and 12.5%) concentration. These prepared polymer systems were evaluated spectrophotometically. It was found increasing in absorption spectra with increasing of the dye concentration in Dye/ poly styrene above composites, which was attributed to the increasing in localized states. The results proved that the best absorption was of (12.5% Methyl Orange / poly styrene), and of the lowest energy gap was (3.15eV), which was the lowest,and of all of the best effect, so prepare 30%MO/PS composite, and hybrid composites((20% Methyl Orange 10%/ Methyl Blue / Polystyrene), (20% Methyl Orange /10% Methyl Red / Polystyrene)) to study its optical, and electrical properties . The optical constant (Absorption Coefficient ) α), Extinction Coefficient (k), Refractive Index (n), Real Dielectric Constant (εr ), and Imaginary Dielectric Constant (εi))for the homopolymer (Polystyrene) , (Dye/ Polystyrene) composites, and hybrid composites at different concentration were investigated at(λc,300nm). It was seen that there was nonlinear relationship between the optical constants and the concentration ratio. The (Spectroscopy Fourier Transform Infrared) spectra showed shifting, appearance ,and disappearance of new band. It was found that charge carrier of (Polystyrene ) was of (P-type),and it was the same for (Methyl Orange / Polystyrene) up to 30% ratio, whereas for (Methyl Blue, Methyl Red),it changed to (N-type) for concentration(≤ 12.5%). The results proved that there was nonlinear relationship between the carrier concentration, mobility, fast increase in the (12.5% Methyl Orange / Polystyrene),(12.5% Methyl Blue / Polystyrene),and hybrid composites by increasing of dye ratio ,and became of order(10-6 ),and of order(10-5) for (12.5% Methyl Red / Polystyrene) composite ,which of within semiconductor conductivity in polymer scale.

Study the Effect of Fired Kaolin on Some Properties of Concrete

By: RAMY JOZEPH AGHAJAN SOLDOZIAN    Supervised By: Assist. Prof. Dr. SHIHAB AHMAD ZEIDAN   year: 2012

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In this research local raw materials are used in the preparation of concrete mixes. Iraqi specifications (I.O.S) and American specifications (ASTM) are adopted, in determining the components of concrete, raw materials in different ratios weight of Kaolin (K) and MetaKaolin (MK) at a ratios of (5%, 10%, 15%, 20%) at different temperatures (150, 300 500 700, 900) ° C added to a mixture of concrete, to achieve the pozzolan interaction between [(K) or (MK)] and cement. The mechanical, physical and pH effects by additions [(K) and (MK)], has been observed fixity of the compressive strength and tensile strength when add the rates ranging between (5% and 10%) of (MK) and a decrease of the ratios greater than (15%), the mechanical properties increased with increasing temperature of (MK), except for temperature less than (300) ° C. The density has decreased by increasing the proportion added, but increased with increasing temperature. The rate of absorption of water was observed that increasing the proportion of (MK) added, decrease the rate of absorption of water and also by increasing, the temperature of (MK), decrease the rate of absorption of water. The percentage of water absorption decreased with the increasing temperature of (MK) and also increases the proportion of added (MK), decrease absorbance. Also noticed, the acid of (MK) did not changing largely in the cement base in the concrete mix, especially in the grades more of the temperature (500) °C, and In general, observed staying concrete material within the limits of base material.

Study on Diffusion Bonding in Solid State of Gray Cast Iron

By: Rasha Rahman Rawhdan    Supervised By: Asst. Prof Dr. Awfa Abdul-Rassol Abdullah    year: 2012

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Diffusion bonding of gray cast iron to gray cast iron experiments were carried out in air atmosphere and in inert gas (Argon) under different pressing load, temperatures and time to find the optimum bonding condition experimentally which affect the bond strength. The pressing load are 1 and 2 ton, the bonding temperatures are 700, 750, 800, 850, and 900ºC, and bonding time 15, 30 and 60 min. To evaluate the bond strength the shear test investigation was performed, the actual bonded area was calculated by using a computer package called (Auto Cad 2006). After calculating the bonded area, shear strength values were predicted for each bonded specimens, the results show that the bond strength increases with increasing the temperature, the bonding temperature brings about an improvement in bond strength but to a certain limit only. Any further rise in temperature will impair the strength owing to a grain growth as well as increasing carbide precipitation. Bond strength also increases with bonding time, the increase in bonding time has a positive effect up to a certain limit, any excessive holding time impairs bond strength. The highest value of shear strength of gray cast iron to gray cast iron joints is (155.7 MPa) at bonding temperature of 900ºC for 30 min holding time under pressing load of 1 ton. Improvement in the bond strength when the pressing load raises mainly attributable to the increase in the area of actual contact between the mating surfaces. Pressing load will raise bond strength up to a certain value, any further increase in pressing load reduces it. It found that the bond strength increases with increasing pressing load . For inert gas (Argon) experiments. No reliable results are obtained for the bonded during shear test may be due to abominable argon gas and this prevents forming of bond. Vickers microhardness testing was carried out to measure hardness distribution in gray cast iron joint. Vickers microhardness testing was performed on unetched specimens using 0.9 Kg load with 15 sec indentation time. The results observed from microhardness test show that the hardness increases with increasing bonding temperature due to formation of hard phased iron carbides (Fe3C). Microstructure of the interface was carried out by using optical microscope before and after the experiment. The microstructure results show the formation of carbide and the carbide precipitation increases with increasing the bonding temperature and time.

Study The Physical Properties of Polymer Blends Reinforced by Metal Laminates and Micro Cotton

By: Alaa Mohammed Hamzah Kaftan   Supervised By: Prof. Dr. Balkees M. D. Al-Dabbagh   year: 2012

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This research includes the preparation of polymers mixtures consists of resins (Unsaturated Polyester with Polyurethane) (UP+PU), where the optimal mixing ratio has been selected on the basis of the best impact strength, and the mixture have appropriate essential mixability and good morphologic properties. It is found that the mixing ratio with percentage (60% Polyester+40% Polyurethane) because it has the highest impact strength, where it has been used to prepare the samples. A four samples where prepared from the polymers mixtures using the above mentioned mixing ratio by using the method of hand casting technique; these samples are: polymers mixture consisting of (UP+PU), added to it the micro cotton powder (MC) with weight ratio (2wt%) once and for copper by weight ratio (39wt%) again, with volume fracture (5%), as well as composite material was prepared from the same polymers mixture adding to it micro cotton powder filling and chips together in the same weight ratios mentioned earlier. Some mechanical tests were conducted include: (Impact strength (Charpy type), Flexural strength, Hardness (Shore D), Tensile strength, Compression, and Roughness surface test, and some physical tests include (Thermal conductivity and diffusivity), these tests carried out in two stages; first on samples (without immersion) and then on immersed samples in (distilled water and diluted sulfuric acid (0.05N)), where the readings are recorded every two weeks for a period of (8) weeks, in addition the effect of increasing the temperature (20±1 °C (R.T), 35 °C, 50 °C) has been studied on the samples. A sample of the four polymers mixtures have been examined using the Scanning Electron Microscopy (SEM), and study the effect of adding reinforcement materials, and also study the topography of the surface of each sample and the knowledge the fine structure for each mixture. Results showed that the reinforced blends with micro cotton powder and copper (UP+PU+MC+Cu) possess better mechanical properties of Impact strength, Flexural strength, Tensile strength and Modulus of Elasticity (Compression), also it has the highest surface roughness and thermal conductivity before and after immersion in chemical solutions. While for the absorbency of solution, all tests are affected by chemical solutions.

Physical and Mechanical Characterization of (Polymer – Ceramic) Composite.

By: Lubna Ghazi Abd Al-Latif    Supervised By: Dr. Balqees M. D. Al-Dabbagh   year:2011

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This research consists of two parts: first; preparation of samples and after that exposure of these samples to some physical and mechanical properties tests. The tests are done at room temperature and then with the effect of immersion in three liquids (Tap water, NaOH (0.5N), and Benzene). Also we exposed some samples to sunlight to study the effect on some properties. First we prepared five kinds of specimens, PS resin was the matrix in all kinds using a casting technique; the samples were: (PS+EP) pure blend with a weight ratio of (80%PS+20%EP), PS pure resin filled with GP once and FS once again making a composite with a volume fraction of 15%GP and 15%FS respectively. Also we prepared composites from (80%PS+20%EP) blend filled with GP once and FS once again with a volume fraction of 15% to both; all samples were prepared at room temperature. Some mechanical and physical properties were investigated by performing tests such as: (impact strength (Charpy type), bending (3-point loading system), hardness (Shore D), thermal conductivity, and diffusion behavior); these tests carried on the samples in both normal conditions (without immersion) and after immersion for a period (2-10) weeks measured every (2) weeks. The results show that at room temperature, impact strength of (PS+EP) pure blend appears to have the highest value. Composite specimens filled with FS filler show the best results in the (thermal conductivity, hardness, and bending) tests. The immersion conditions indicated remarkable effect on all the examined physical and mechanical properties, compared to un immersed samples, also the exposure to sunlight has the same effect. In case of tap water immersion, the (PS+EP) blend that filled with FS has the highest diffusion coefficient value while (PS+EP) pure blend gives the lowest value. In case of NaOH immersion, (PS+EP) pure blend showed the highest value of diffusion coefficient while (PS+EP) filled with GP showed the lowest value. Benzene shows the strongest effect on examined physical and mechanical properties also diffusion behavior, since no weight gain in any sample was observed.

Study of some Mechanical, Oxidation, and Corrosion Properties of Metal Alloys used in Manufacturing of Petroleum Towers

By: Laith Nadhim Abbas    Supervised By: Assist. Professor. Dr. Sanaa Abdulhadi Hafad   year: 2011

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In this research the diffusion coating process by the single preparation method of (Al) metal, dual preparation method of (Al,Si) metals and third preparation method of (Al ,Si ,Cr ) metals on different alloys (Inconel alloy, Monel alloy, Stainless steel alloy type (316L), Stainless steel alloy type (321) and Low carbon steel alloy). Which are used in the production of manufacturing of Petroleum towers such of carbon steel and alloy steel families. All the heat chemical treatment in the (1100°C) and in the average period (20) hour per each treatment. The effect of diffusion coating on alloys. Can be seen in the microstructure test processes and X-ray diffraction test. It is clear from the XRD test, the appearance of new phases for all coating alloys. X-ray Fluorescence test, which appears metals contents showing the change in percentage in (Al, Si, Cr) alloys according to coating's method. Microstructure test which is metal and alloy identity indicates the change inside the alloy due to Coating and Calculates the coating thickness for each phase. In Monel alloy the thickness of Al coating was 400µm. From hardness test by using Brunel method, we found that the hardness increase with all Kinds of coating. For example, the hardness of Inconel alloy before coating was 179 Kg/mm2, increase to 255 Kg/mm2 with Aluminizing coating, 260 Kg/mm2 with Siliconizing-Aluminizing coating and 275 Kg/mm2 with Crninizing-Silcinazig-Aluminizing coating. The results of the wear test for used alloys under constant weight (2kg) and for constant time(30min), Indicate that the wear rate decrease after coating processes. It is clear from the results that the wear rate is less for third coating than the dual and single coating. In the corrosion test process we used salt solution (NaCl). For testing the alloy before and after coating the salt concentration in the salt water known as the most corrosive condition and the result show the resistance of alloys increased after coating. Finally, Oxidation test for alloys in the air at (700°C) and rate (6 hour) for each period (totally 36 hours). Shows an increase in the weight (thin film oxidation content) which then increase Oxidation resistant.

تاثير خلط البولي ستايرين مع المطاط على الخواص الميكانيكية والبنية

By: كرار مهدي كاظم   Supervised By: الدكتورة بثينة علاء الدين أبراهيم   year: 2010

Abstract

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The thesis involved preparation of polymer blend as two systems, the first PS/ABS prepared by single screw extruder, the second PS/SBS prepared by Haake PolyDrive extruder. Different composition ratios were used with the aim of arriving at the best physical blending percentage In order to study the influence of blending on the mechanical properties, thermal properties and morphology several tests are performed including (tensile, impact resistance, Differential scanning calorimetry (DSC), optical microscopy and scanning electron microscopy). The results from this work show that the mechanical properties for blend system PS/ABS at compositions 70/30, 60/40 and 50/50 have mechanical properties mach better than the pure constituents. The mechanical properties for the blend system of PS/SBS, dependent on the amount of SBS content, indicate in general it nearly obeys rule of mixtures. The (DSC) test for blend system of PS/ABS gives good indication of improving state of miscibility for most blend ratios; there is only one glass transition temperature between the two values for pure polymers. Also the DSC results for blends system of PS/SBS give good indications of improving state of partial miscibility. The optical microscope and SEM results for both systems fully support the results obtained from the mechanical properties. The FTIR results for PS/ABS blend system show that the PB phase in pure ABS has a cis configuration and these configurations change from cis to trans for all blend ratios.

Study of Thermal Aging Effect on Optical Properties of Some Polymer Blends

By: Marwa Raheem Fraih   Supervised By: Dr. Nahida. J.Hameed   year: 2010

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The present work was carried out in two stages .The first stage was concerned with study of the blending ratio effect on the optical properties of the polymer systems involved (PMMA, PC, and PS), binary blends (PMMA/PC, PMMA/PS, and PC/PS),and ternary blends (PMMA/PC/PS) at different concentrations. The second stage was concerned with study of thermal aging effect on the above homopolymers, and the polymer system of best optical properties. The samples were casted as films from the homopolymer stated above and the blends as a binary and ternary blend at different concentration. These prepared polymer systems were evaluated spectrophotometically for selecting the polymer systems of the best optical properties. It was found that 50%PMMA/50%PC binary blend has the best optical properties. The results proved that its energy gap was (2.5eV), which was the lowest of all polymer system involved. The homopolymers above and 50% PMMA/50% PC binary blend were subjected to thermal aging within range of (50-250C) for (2hr) to study the effect of thermal aging on their optical properties. The absorption spectra of the thermally aged polymer systems showed heating induced absorption changes in the wavelength range, which depends on the polymer type and polymer blend. The thermal degradation caused increment in the absorption of degraded samples. The increment depended on polymer type and polymer blend, especially at 250C in the thermally aged PS samples (2.3eV). Decreasing in absorption was found for cases in which, thermal degradation caused surface damage i.e. crazes or cracks formation. The optical energy gap and urbach energy were calculated the absorption spectra before and after thermal aging to the polymer systems involved. The results showed nonlinear relationship between the optical constants and blend ratio, it was attributed to their immiscibility. The nonlinear relationships between the optical constant of the thermal aged polymer systems and polymer blend with the heating temperature was attributed to the unsystematic thermal degradation induced by heating, it was found PMMA and PC have the best heat resistances in comparison with the polymer involved . Morphological investigations for the surface damages (crazes, and cracks) caused were performed by optical microscope .It was found that the thermal degredation could easily lead to some mechanical surface damage. FTIR spectroscopy was carried out for polymer systems before and after thermal aging to identify the region of the main characteristic bands and its results were investigated.

Effects of Fibers on Damping Behaviors OF Composites Materials

By: Hiba J. Jaafer    Supervised By: Dr. Sabah S. Abdul-Noor    year: 2010

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Epoxy and unsaturated polyester resin was used as a matrices for composite materials, with carbon, glass, and copper fibers as reinforcement materials with volume fraction (Vf =1%,2%,3%). Six types of composites were prepared:- (1) Epoxy reinforced with continuous carbon fibers . (2) Epoxy reinforced with short carbon fibers. (3) Epoxy reinforced with continuous glass fibers. (4) Epoxy reinforced with short glass fibers. (5) Epoxy reinforced with continuous copper fibers. (6) Epoxy reinforced with short copper fibers. And another six types of composites were prepared :- (1) Unsaturated polyester reinforced with continuous carbon fibers . (2) Unsaturated polyester reinforced with short carbon fibers. (3) Unsaturated polyester reinforced with continuous glass fibers. (4) Unsaturated polyester reinforced with short glass fibers. (5) Unsaturated polyester reinforced with continuous copper fibers. (6) Unsaturated polyester reinforced with short copper fibers. Research subject was implies studying some of mechanical properties for composite materials in Natural conditions. Mechanical properties that be studied were :- ( Vibration damping, and studying, deflection, stiffness, natural frequency, and damped period. The research results showed that the values of (Stiffness, Natural Frequency, Vibration damping and Damped period) will increasing with the increase of the volume fraction of reinforcement materials used in this research, in the other hand the values for deflection will be decreeing with the increase of the volume fraction of the reinforcement materials used.

Studying Mechanical properties for polymer Matrix composite material reinforced by Nature Filler

By: Areej Ryadh Saeed    Supervised By: Sewench Noraldeen Rafiq    year: 2009

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The polyethylene (PE) is a commercially important Thermoplastic polymer, which is of practical use in a wide variety of engineering applications. So that if one wants to extend the field of application of this material, an improvement of the mechanical and physical properties is usually necessary. A relatively easy way to improve the, mechanical, and physical properties of the polymer is the addition of filler materials, to obtain a composite materials with a good properties. In this research we use both High Density Polyethylene (HDPE), and Low Density Polyethylene (LDPE) as matrix to the composite material and we use coconut shell particles and fish shell particles as a reinforced fillers , we use the above to prepare the current research samples that we study in different Filler Percentage as below :- 1. Pure High Density Polyethylene (HDPE). 2. Pure Low Density Polyethylene (LDPE). 3. High Density Polyethylene (HDPE) reinforced with coconut shell particles in the following percentage (15, 20 and 30%). 4. Low Density Polyethylene (LDPE) reinforced with coconut shell particles in the following percentage (10, 15 and 20%). High Density Polyethylene (HDPE) reinforced with fish shell particles in the following percentage (30, 40 and 50%). 5. Low Density Polyethylene (LDPE) reinforced with fish shell particles in the following percentage (30, 40 and 50%). In this research we study some mechanical properties like (Modulus of elasticity, Impact strength Hardness, Compression strength, and Creep rate). We also study Absorption test which is one of the physical properties, we study it for all the prepared samples and then we calculate Diffusion Coefficient after the samples were immersed for a period of time lasted for three months in the water. The research results showed that the values of (Modulus of elasticity, Hardness) will increase with the increase of the Filler Percentage for both reinforced fillers and for both types of Polyethylene used in this research, in the other hand the values for Impact strength will be decreeing with the increase of the Filler Percentage for the reinforced fillers used. And we found also that the values of Creep rate of the all samples used in this research will be decreeing with the increase of the Filler Percentage of the reinforced fillers used. In the Diffusion test we noticed that the Diffusion Coefficient decrease with the increase of the Filler Percentage of the reinforced fillers used.

Performance of some transmission lines using different dielectric materials

By: Zainab Naif Rasheed    Supervised By: Assit.Prof.Dr.Mahdi Hassan Suhail    year: 2009

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The transmission line has a single purpose for both the transmitter and the antenna. This purpose is to transfer the energy output of the transmitter to the antenna with the least possible power loss. How well this is done depends on the special physical and electrical characteristics (impedance and resistance) of the transmission line, The purpose of this thesis involves the study of the characteristic impedance and the other characteristic of the coaxial transmission line like (Wave impedance, Reflection coefficient, Maximum value of electric field inside the line, Power, Current in the conductor, Capacitance and Inductance per unit length, electric and magnetic field).The parameters of the Two wire transmission line like (Reflection coefficient, Admittance, Voltage and Current as a function of distance X from load and Line loss) have been studied. Mat Lab program (Version 7) is used for design and simulation of the microwave circuit using two types of Transmission line in X- band frequency. An implementation has been done on coaxial transmission line of (53.5Ω) characteristic impedance for three type of dielectric material including Polyethylene, Teflon, and Nylon)where their permittivity = (2.25 ,2.1 & 4) respectively .The results shows that impedance of the line depend on the dielectric constant ( ) of the insulated material ,as the ( ) decrease the impedance value increase inside the line for the same dimension, in addition to that the value of the impedance in the coaxial line decreases as the inner radiuses (a ) and outer radiuses (b) increases. Two-wire Transmission lines were also studied (with characteristic impedance was 300 Ω).Three types of dielectric material (Polyethylene, Tyflon, and Nylon), Nylon was excluded from the studies because it was not practical in manufacturing .The parameter previously mentioned in this system have been studied with matching & mismatching cases, matching load , and resistive load , for polyethylene and Teflon. The optimal value of the line parameters occur when the line terminated to resistance equal to characteristic impedance of the line. But when the line terminates to load resistance less than characteristic impedance we obtain maximum and minimum value along the line, while the value changed in phase shift when terminated the line to load resistance greater than characteristic impedance of the line. This phase shift depends on the parameters and the effect of ( ) on them, the phase shift exists on the incident wave because of the additional losses (capacitance & inductance losses).

Studying of Some Electrical and Mechanical Properties for Polyaniline (PANI) Composites

By: Samah Mohammed Hussein    Supervised By: Dr.Sewench N.Rafeeq   year: 2009

Abstract

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As ordinary known the ability of synthesizing electrical conducting polymer composites is possible but with poor mechanical properties, for the solution of this problem, we carried out this study in order to obtain that both properties. Three methods were applied for preparing the conductive PANI composites using both glass fiber and Kevlar fiber fabrics as substrate for the deposition of the PANI at one time and the prepared composites (EP/glass fiber)and (EP/Kevlar fiber) at others. The chemical oxidative method was adopted for polymerization of the aniline and simultaneously protonated of PANI with a hydrochloric acid at concentration (1M).Two kinds of oxidation agents (FeCl3.6H2O) and ((NH4)2S2O8) were used. The electrical measurements indicate the effect of each preparation method, kind of oxidant agent and the kind of material which PANI deposited on the electrical results. The conductivity results showed that the prepared composites lie within semiconductors region. The Hall Effect measurement showed a p-type behavior for the composites prepared by the first and third methods, and n-type behavior for the composites prepared by the second method. Temperature –dependence of electric conductivity results showed semiconductors and conductors behavior of these materials within the applied temperature ranges. The mechanical properties(tensile strength, creep behavior) was studied, the results as a whole concluded that PANI precipated on the EP/glass fiber and EP/Kevlar fiber composites has no remarkable effect on the mechanical properties as compared with the untreatment composites with PANI. The morphology of PANI composites showed the regularity of PANI deposit on the EP/glass fiber and EP/Kevlar fiber composites and some fibrils structure and PANI moieties on the Kevlar fiber and glass fiber fabrics respectively. The X-ray diffraction study showed the crystalline structure for EP/Kevlar fiber/PANI composites prepared by the three methods. These results gave optimism to the synthesis of conductive polymer composites with excellent mechanical properties.

A Study Of Magnetic Properties Using Some Theoretical Models

By: Dhia'a Khalid Kudeer   Supervised By: Prof. Dr. Sa'ad Naji Abood    year: 2009

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In this work, the occurrence of spatially modulated structure in several competing interactions are examined . Of particular interest are the situations where, for given values of the interactions, the ground state is infinitely degenerate. Most of the work presented here concerns the analysis of how this zero-temperature multidegeneracy can be removed by the interaction of weak perturbations such as spin anisotropy, external magnetic fields, or quantum fluctuations . Many different studies of ferromagnetism and anti-ferromagnetism models have presented theories on energy minimization. These studies, however, do not give visual confirmation of what is occurring during minimization. One wish to study how the energy minimizes locally in a ferromagnetic system. Where does the energy dissipate once the magnetic field is applied? Are there regions that exhibit a chaotic nature before eventually aligning with an external magnetic field? It has been demonstrated that the energy of the system will minimize in the presence of an external magnetic field. However, regions within the lattice may not converge at the same rate. Our goal is to develop and apply a visual tool to the system, which would allow users to visualize the minimization process. In this thesis, one describe a model and visualization system designed to illustrate the principles of energy minimization in ferromagnetic system . Models of finite or semi-infinite chains of spins are considered where the competition between surface and the bulk effects creates adomain wall (kink) in ground state. In this work, the aim is to discuss the role of a hitherto fore unexplored parameter on the unbinding transition: the spin anisotropy. One should know that, as discrete spins with -fold spin anisotropy soften, layering transitions can be stabilized in simple, short-range clock models, even at zero temperature (for ). In particular, one can, in a chain of ferromagnetically coupled (XY) spins. Using an expansion in inverse spin anisotropy , one can, calculating analytical solutions to the equilibrium equation ( ) under the influence of a magnetic field for materials ferromagnetic and inti ferromagnetic. one can to rely on numerical methods that adopted is based on several programs as (Fortran Code 77, 90) , and Chou-Griffiths algorithm method, to build the phase diagrams exhibits points where two multiphase lines meet at a first order transition. When the spin anisotropy is infinite. one can calculate the energy differences, , between neighboring interface states. Then the special case is considered, where the multidegeneracy cannot be lifted for small values of , In this case we consider the quantum version of the model and show the quantum fluctuation can raise the multidegeneracy stabilizing an infinite sequences of layering transition . The effects of quantum fluctuations on the behavior of an interface are considered further in the case of three dimensional transverse Ising model in a semi-infinite. One find that, for zero transverse field, the short range nature of spin interactions is responsible for the appearance of a multidegeneracy with respect to the position of the flat domain wall. For a non-zero transverse field, the multidegeneracy can be splitted by quantum fluctuations and an infinite sequence of layering transitions is stabilized . The aim is to construct the phase diagram which gives the position, , of interface as a function of the uniform field and the transverse field . A chain of antiferromagnetic coupled (XY) spins with two-fold anisotropy is studied in an external magnetic field. The analytic and numerical results reveal that in semi-finite and finite chains of even-length, there is a sequence of layering transitions in the bulk that has not been previously identified. The solitonic-like solutions predicted by the continuum semi-classical two–dimensional XY -model are investigated using canonical Monte Carlo simulation. In particular, we verify the existence of kink states, and study their degree of stability. These states, that were supposed to exist from approximate theories applied to the continuum limit of this model, are a new kind of solution of the XY model under external magnetic field. In the simulation several system sizes up to spins were considered. The study of the static spin correlation between the initial and final configuration shows there exist a finite transition temperature Tc, which is independent of the system size. According to our simulation, at T < Tc the kink state is stable, and the degree of stability increases with system size. Magnetization per site , energy per site , magnetic susceptibility, specific heat of a Ferromagnetic materials are Calculated as a function of temperature for spin lattice interaction of the 2D Ising Model for some experimental values of ferromagnetic materials such as Gadolinium Chloride at Curie temperature , and ferromagnetic thin film from Nickel growth on cooper at Curie temperature , in zero and nonzero magnetic field.

Some Factors Effecting on the Dielectric Strength for Composites (PVC- Ceramic)

By: Farah Jameel E. Al- Zubaidy    Supervised By: Shehab Ahmad Zedan Al- Jeboori   year: 2009

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This research contains a study about the effect of adding burning and non burning Kaolin as a support to (PVC) the matrix material and studying some effecting factors on the dielectric strength. The non- burning kaolin was added to the (PVC) in a weight proportion (1%, 2%, 3%, 4%), after burning the kaolin at ( ) for two hours, was added to (PVC) material in the same previous weight proportion, the samples were prepared by the warm pressing method with (0.8- 2mm) thickness. The testing results shows that the dielectric strength decreased when the burnt kaolin is added because of existence of crystallize water, on the other hand adding burnt kaolin the lack of dielectric strength refer to existence of changes in lattice structure of powder clay’s. The value of dielectric strength for (PVC- non burnt Kaolin) composite was less than (PVC- burnt Kaolin) composite because of existing of crystallize water which have high dielectric constant, but it marked by high coefficient losing factor compared with other dielectric materials. The dielectric strength decrease with increase in electrical factor loss. The results shows for two composites (PVC- non burnt Kaolin) and (PVC- burnt Kaolin) in succession decreasing in dielectric strength with increase in thickness and the dielectric strength are increased with an average time of voltage evaluated for each composites. The effect of cycles number on the dielectric strength for both composites shows decreasing of dielectric strength which was obvious after the first cycle. Also the dielectric strength were decreased with temperature increasing for both composites. The getting photograph photos of breakdown region were shown by using the optical microscope are shown carbonized samples in the breakdown region because of destroy polymers chains for (PVC) polymer, and micro cracks are formed due to breakdown especially when we added high percentage of non- burnt Kaolin extended directly form breakdown point. The photos of burning kaolin, shows that the macro cracks was more zigzag than in the case of non- burnt Kaolin because of high hardness and increasing of brittleness of the material.

Study of Degradation Effect ON Physical Properties of Methyl Orange Doped PMMA

By: Mohammed Salman Kadhim    Supervised By: DR. Nahida. J.Hameed    year: 2009

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The samples are cast as thin film from homopolymer (PMMA) before and after doping with methyl orange at different concentration. The samples are exposed to UV-radiation for exposure time within (10-50hr) range. At other time the samples were heated to (100-110 and 120°C). These polymer systems were evaluated spectrophotometrically. The absorption spectra of exposed samples show radiation induced absorption changes in the wavelength range, which depends on the dopent concentrations. The photodegradation increases the absorption of degraded samples. The increment depends dopant concentration, especially in ultra violet region in exposed PMMA doped with methyl orange at 6.7×10 -2wt/wt concentration. The decreased in absorption is seen for the cases in which photo and thermal degradation had caused surface damage, chain scission formation, especially in ultra violet region in the PMMA samples. Calibration curves are drawn at peaks of selected wavelength in the absorption spectra. The linear regions from the calibration curves are selected. Energy gap shift ,with thermal aging of PMMA before and after doping with Methyl Orange exhibited significant change at (110°C), is near the (Tg) of (PMMA). Morphological investigations for the surface damages (chain scission) caused by thermal and photo degradation are detected by optical microscope. It is found that the photo degradation and thermal aging could easily lead to some mechanical surface degradation. The effect of dopant concentration on dielectric constant and thermal conductivity is also studied. The results show increase in dielectric constant with increasing dopant concentration. PMMA doped methyl orange at 6.7х10-2wt/wt concentration selected to study dielectric constant and thermal conductivity due to its best response. It is found that there are systematic changes in its dielectric constant, and thermal conductivity with its response range.

Studying the Effect some Physical Properties of Cd2SnO4 Thin Films Prepared by Spraying Pyrolysis Technique

By: Zahraa Hussien Heyat    Supervised By: Prof.Dr. Ala’a A. Al ـ Niamy and Assist.Prof.Dr Muslim F. Alـ Zubaydy    year: 2008

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In this study, (Cd2SnO4) thin film has been prepared by Spray pyrolysis on the slides glasses of ( 0.2 M ) fro (CdCl2.2H2O) and (0.2 M,0.1 M) from (SnCl4.5H2O) . some films were prepared in different temperature ( 543,583,703) k, also it is preparation some samples in different spray distance (24,29,34) cm,and also it is prepared some samples in two flow rates of gases (24,27) ml/min and it is prepared another samples (Cd:Sn) in different volume concentrations(1 : 1,2 : 1) , and also we will make annealing process at temperatures (873 k) and for ( 60 min ) . It is obtain from the test of X – Ray diffraction that the deposition films at low degrees of temperature was crystalline and these films be amorphous at high degrees of temperature. The heat annealing of the films decrease the crystal defects and that increase the film’s crystalline degree and begin to growth crystal planes to amorphous films. The optical measurements obtained that the films have high transmition in visible region and that make it transmition materials for that region where it have transmition between (55 % - 97%) from wave lengths (740 – 900 ) nm ,and the annealing film’s tansmition increase and this increase combined with increase the energy gap for annealing films. Also the Absorption coefficient and Extinction coefficient change because of the changing the preparation conditions for the films , like( temperature degree of deposition substrate , spray distance , flow velocity of sputter gas , molarity concentration and volume percentage for contains deposition solution) .

Studying the effect of siliconizing coating for some stainless steels on their mechanical and oxidation Properties

By: Saba Hussein Khadum Al- Khaledi    Supervised By: Dr. Mohammed S.Waheed   year: 2008

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The previous studies carried out siliconizing in pack process in the range of 1000- 1200Cº .They found that the pack mass was sintered ,and stuck to the samples so that it was very difficult to remove the contaminations from the pack.The samples were very much distorted and the grain size of the core increased due to high temperature and prolonged heat treatment. In this study, the synthesis of pack cemented coating was investigated on two stainless steels (304 and 316L), in order to form silicide compounds on their surface at lower temperatures(800, 900, and 950C º) to avoid sintering of the pack and adhesion of material to the samples surface, then studying the mechanical & oxidation properties of these samples. In our investigation silicon was used as a master alloy and alumina (Al2O3) as a filler material. Also ammonium chloride was used as an activator with different weight percentage as (5,7, and 10%), in order to increase the efficiency of the coating layer formation process. The results of X-Ray diffraction allow to conclude that the upper layer obtained is a mixture of intermetallic phases, therefore, we conclude that coating mainly comprises ( Fe-Si ) inter - metallic compounds, this layer is followed by an inter - diffusion zone consisting (Si) inward diffusion in the substrate and outward diffusion of alloying elements as represented by LOM images. The coating layer formation is a temperature and activator weight percentage dependant process, which means that it is a diffusion controlled reaction. Thus the thickness of sample siliconized with pack content 10% activator at 950Cº is higher than sample siliconized with pack content 7% and 5% activator and these samples have higher thickness than samples coating at 900Cº and 800Cº at same conditions. The average coating thickness obtained by siliconizing process after 4hr by using different activator weight percentage for the two selected alloys are : 1- 68.520 - 129.390µm for 304 ss alloy. 2- 75.929 - 192.592µm for 316L ss alloy. Weight gain test result shows different behavior with increasing temperature and activator weight percentage. As temperature and activator weight percentage are increased the weight gain droops to negative value due to formation of iron chloride which encourage the migration of iron from the substrate surface to the pack. In addition to the above, those alloys have shown a great deal of improvement in wear resistance due to the formation of hard phases which clearly contributed in increasing hardness value and ultimate tensile strength. Oxidation test in dry air has also been implemented under a temperature of 850Cº for all specimens of the selective alloys (coated and uncoated ). The results show an enhancement in oxidation resistance for those alloys due to formation of protective oxide scale SiO2 which increase their oxidation resistance. Micro - hardness testing appears a gradual decrease in hardness towards the core indicating that the composition of coating consists of a solid solution of Fe-Si of varying composition at different depth.

Investigation of Multilayer Non Ferrous Metals-Coated Graphite

By: Farah Amer Abed    Supervised By: Dr. Salam Husain Ali and Dr. Sabah Mohammad Ali    year: 2008

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In the present work , a bulk graphite substrate was coated with nickel and multilayer of nickel- chrome using electroplating technology. The experimental equipment and facilities were locally designed and constructed. After steps ( cutting , grinding and cleaning ) of substrates and bath solution preparation, the electroplating process for preparing substrates was began. The deposition conditions ( PH ,distance between electrodes , time of plating and current density ) were varied during deposition process. The heat treatment was carried out or selected electrodeposited specimens at different temperatures for one hour. The test and measurements ( optical examination, thickness measurements, adhesion test and microhardness test) of coated bulk graphite by layer of nickel and multilayer of nickel- chrome were carried out . The optical examination for morphologies of the coated surfaces showed that the variation in deposition conditions are influenced the microstructure of the electrodeposited layers. From the microstructure analysis , it was found that the grain size tend to be smaller as the PH of solution , the current densities and distances between electrodes are increased and time decreased. The effect of heat treatment on the microstructure showed an encouraged grain growth which was more at high treatment temperature. The mechanical tests of electrodeposited layers results showed that the maximum value of adhesion strength was ( 13.75 MPa at t= 15 min. and PH = 3.5) , but most samples show a perfect adhesion strength . Adhesion strength is also enhanced by heat treatment effect due to the diffusion occurred between the coating layer and substrate. The microhardness value of graphite coated by layer of nickel showed to be increased to maximum values ( 585 MPa at PH = 3.5and J= 6.5 A/dm2 ), and the maximum values of microhardness of graphite coated by multilayer of nickel-chrome was 1325 MPa at t = 120 min. and J = 32.6 A / dm2, but the microhardness values decreased by the effect of heat treatment.

Study of the Geometric Shape Effect for Bonding Zone on Adhesive Materials Fracture Strength

By: Logean Qadri Ibrhium Al-Azaway    Supervised By: Dr. Salam Hussein Ali Al-Haddad   year: 2008

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The research may be more advance results which would be very useful in most industrial applications. The effective engineering grooves shape on adhesive toughness and strength, especially at many adhesive materials selected and used (Epoxy Resin, Unsaturated polyester Resin, poly vinyl alcohol, Synthetic Arabic Gum) (UP/EP/ PVA/GR) with sandwich adhesive materials like Wood, Aluminum and Teflon. First stapes, all adhesive materials were experimented and all mechanical properties had been denoted. Sandwich molds could be made from such that selected materials with different engineering grooves shape triangle, squire and circular with asymmetric bonding of (0°, 90°) degree. Shape of grooves and symmetric bonding degree two different angles had be tested and investigated. (EP) resin shows with aluminum molds which has triangle groove, high magnitude of (Modulus of Rigidity) (K) (122.2085 MPa) at zero angle, other wise in (90°) angle shows (95.59055 MPa). The same thing done with aluminum which have squire grooves shape at zero angle, (K) was (95.25825 MPa), (90°) angle (K) equal (284.0124 MPa). Than with circular grooves (K) values at different angles was denoted as (347.1919 MPa) at (0°) angle and (102.8187 MPa) at (90°) angle. The process was made for Wood and Teflon also with same different grooves and different angles (0°, 90°) as well as (UP, GR and P.V.A) used with the same different molds too. An application of (EP) as adhesive materials with Wood was made and found efficient and succeeds with high (K) and low (K) with aluminum receptivity. The experimental results of using (UP) with aluminum mold was (100.7299 MPa), (275.5964 MPa) for angle (0°, 90°) respectively, at triangle grooves, Teflon molds result test was (38.68297 MPa) (14.211714 MPa) for (K) and (0°, 90°) angles respectively and triangle grooves. At squire grooves (K) results was (159.9606 MPa) and (247.1016 MPa) for (0°, 90°) angles respectively. Using (UP) with wood mold found more efficient than another adhesive resins. The result was not succeed when use (GR and PVA) with aluminum and Teflon molds. The experimental result of using (GR and PVA) with wood mold was value (K) (129.5383 MPa), (190.1477 MPa), (38.33469 MPa), (34.73393 MPa) for angle (0°, 90°) respectively at triangle grooves. At squire groove (K) were show (111.8 MPa), (69.19796 MPa), (31.07483 MPa), (38.78967 MPa) for (0°, 90°) angles respectively. The experimental results of using (GR) with wood mold which has triangle grooves at angle (90°) and using (PVA) with wood mold which has squire grooves at angle (0°), shows higher fracture resistance.

The effect of the time and temperatures of firing in the mechanical properties of aluminum compact which reinforced by silicon oxide

By: Mohammed Taher Hamza    Supervised By: Dr. Mohammed Saeed Waheed   year: 2008

Abstract

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In this work metal matrix composite was produced by powder metallurgy method (M/P). Aluminum powder was used as matrix and silicon oxide was used of (106 µm) particle size at weight percentage ( 5%, 10%, 15%, 20%) from silicon oxide as first stage. Then the sample were formed by unaxial pressing by using hydraulic press with pressure equal (5 ton) sintered in side electric furnaces under atmosphere of inert gas (argon) at different temperatures as fallowing: • 470 ˚C for (one, two, and three) hours In the second stage the same particle size that have been chosen , and used weight percentage (5%) from silicon oxide which reinforced to aluminum and the sintering process was done as the following: • 500 ˚C and 530 ˚C for (one, two, and three) hours All samples were subjected to the following: Density and porosity and Hardness and Compressive strength and X-Ray diffraction to determine all phases. It was found that the density increase after sintering , and in X-Ray diffraction was found there is no new phase exist after sintering, at all sintering temperature that sintering by it and any time and period for all the weight percentage. Also it was found that the hardness is increased with increment of the amount of added particles, and the hardness is increased with increment of the sintering temperature, except at temperature (530 ˚C) the hardness was decreased when that it was in temperature (500 ˚C) . and the hardness is increased the sintering time temperature except temperature(530 ˚C) . Also it was found that the compressive strength increased with increment of the amount of added particles, and the compressive increased with increment of the sintering temperature, except at the temperature of (530 ˚C), the compressive strength decreases when that it was in temperature (500 ˚C) . And the compressive is increased the sintering time temperature except temperature (530 ˚C). From the wear test it is found that the wear resistance increase with the increasing the weight percentage of SiO2 particles, and the wear resistance with increasing the sintering temperature except at temperature (530 ˚C), and the wear resistance increases with the increasing the sintering temperature and the period of sintering temperature.

Wear Resistance for Thermosetting Polymer Blends

By: Huda Jabbar Abdul Hussein    Supervised By: Dr.Balkees Mohammed Dyaa    year: 2008

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The research involves study of Adhesion wear resistance with changing load applied and also asliding velocity, disc's type was studied also for polymer blends using Epoxy ,Unsaturated Polyester and Novolac phenol,as a thermosetting blend was prepared as binary and ternary polymer blends; using these resins with that ratios as follows: 1- Binary blends (EP/UP) at blend ratios (80%/20%). 2- Binary blends (EP/Nov) at blend ratios (80%/20%). 3- Ternary blends (EP/ UP /Nov) at blend ratios (80%/10%/10%). 4- Ternary blends (EP/ UP /Nov) at blend ratios (60%/20%/20%). Also compression strength and shore hardness were studied before and after immersing in chemical solutions (NaOH,HCl) with concentration (0.5) normalit ;Diffusion coefficient were calculated for blend in (NaOH,HCl,NaCl, H2O) . In general the wear resistance was increased in binary blends from (2.3873 gm/cm) compared with the ternary (0.9018 gm/cm); also increased with increasing load applied till (20N) from (0.5093 - 4.0319 (gm/cm)). also wear ratio increase with increasing immersion time at amount (4.5624 gm/cm) . The effect of base solution (8.1169 gm/cm) was greater than that of the acid (4.7746 gm/cm) in all blends. Wear resistance was increased in brass disc (1.5415 gm/cm) compared with iron disc (0.3713 gm/cm). Compression strength was decreased after immersing in solution and also shore hardness. Diffusion coefficient (Dx) was less one for binary blends (80%EP/20%UP) compared with other.

Study the effect of the changing in crystal structure of the Iraqi petroleum coke on electrical properties

By: Huda Hussein J. Al – Tememy    Supervised By: Dr. Salam Hussein Ali Al-Haddad   year: 2008

Abstract

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In this study it has been used the powder of petroleum coke from type needle coke as a filling material which content high percentage of carbon element and it was used a carbohedric material as a bonding material represented with a sugar solution (sugar & water) where sugar is classified in hydrogen cokes family, and this type of carbohedric residue carbon element during heat process. We were chosen four grain sizes from the filling material and every size of them would be divided to four samples and put them under a different medium heat temperatures reached to (1000oc). During heat treatment we get lose in weight of the samples against increase of the true density for them. Then we added the bending material (which was (16%) and equal to (0.2 gm) from the whole weight of the sample), and after homogenous mix and press processing we would dry the samples in (180oc) and then we make the electrical test. The best results were for the samples which have lower grain size and it represented with (D1 , D2 , D3 and D4); where the electrical conductivity was [ (0.329) , (0.482) , (0.739) , (1.522) ] (Ω.cm)-1 respectly , and for the other sizes the best results were for it which had heat treatment at (1000oc) where it was [(0.780) , (1.005) , (1.302) , (1.522)] (Ω.cm)-1 respectly, X – ray diffraction to the samples which had heat treatment in (1000oc) and for the samples which have lower grain size and had heat treatment in different temperatures, we observed that the grain size and temperature of heat treatment effect the crystalline degree where the crystalline degree increases when the grain size decreases and the temperature of heat treatment increases.

Study Mechanical Properties of Polymer Blend Using Thermoplastic Polymers

By: Bushra Hosnie Musa Al -Shaeban    Supervised By: Balkees Mohammed Dyaa Al-Dabagh   year: 2007

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This research including preparation a thermoplastic polymer blends to improve its mechanical & physical properties, the blend used was (HDPE) High Density Polyethylene & (HIPS) High Impact Polystyrene, with different weight ratio and compare it with its components individually using Single Screw Extruder. The behavior of this blend was studied using some physical and mechanical properties such as ( Hardness , Compression, creep , Impact , Bending , Thermal conductivity & Diffusion coefficient of these blends with solutions (Nacl ,KOH, HNO3) with Normality (0.5 N). It was found that HIPS decreased the Impact strength & Thermal conductivity when adding to HDPE ,also Compression strength decreased unless the ratio (90 HDPE/ 10 HIPS)% found increased . Also adding HIPS to HDPE increases Hardness, Creep strength, Young modulus and the higher Young modulus was (70 HDPE/ 30 HIPS)%. Diffusion Coefficient ( D ) was calculated for all samples in a chemical solutions(Nacl ,KOH, HNO3) with Normality (0.5 N) for three months ; the higher value for D was for Nacl & HNO3 solution for HDPE and HIPS alone ; the higher D for blends was found in KOH for (90 HDPE/ 10 HIPS)%.

Improvement of Local Novolac and Studying some Thermal , Mechanical Properties and Erosion Resistance.

By: Hazim Faleh Hassan    Supervised By: Dr. Balkees.M.Deya   year: 2007

Abstract

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The research involves using phenol – formaldehyde (Novolak) resin for making Novolak compact with hexamethylenetramine in different ratio (15%) and (20%) by weight , also this work involves preparing composite material by using Novolak as a matrix , while flint was used as rein forcing material and making composite compact with same ratio of hardener . The research was studied mechanical , physical , thermal and electrical properties for all specimens in natural conditions and after immersion in natural water . Mechanical test included ( hardness , compression and adhesion force ) , while thermal tests included thermal conductivity and Erosion resistance , this test included photographs pictures further , physical test were studied including the specimen's absorption after immersion the samples in distilled and natural water . Electrical tests were studied including relative dielectric constant for all samples . In general the results have show that flint and increasing of hardener (HMTA) leads to enhancement hardness , but at the same time give negativity effect for compression . The results show that the flint and increasing the (HMTA) positivity affect the erosion resistance but negativity affect the thermal conductivity. For relative dielectric constant , flint and increasing the (HMTA) leads to improvement relative dielectric constant . The results show that the immersion in water leads to decreasing mechanical properties and relative dielectric constant but increase thermal conductivity .

A Study of Some Physical Properties of (Cd) Films deposited by Locally fabricated D.C. Sputtering

By: Ahmed Sattar Jabbar AL-Zubaydi    Supervised By: Dr. Ali M. Mousa AL-Zuhery Dr. Adawiya J.Haider AL-Shammary   year: 2006

Abstract

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In this work, we designed and fabricated a d.c. sputtering system for deposition of different films. The cathode was made of copper metal and consists of two main pieces, first was a disc contains a cylindrical cavity for fix the sputtering target. This disc is fixed to the second piece of cathode, which is the lower cylinder using (4) nuts and rubber O-ring to prevent leakage during operation of the system. The cathode was covered with cylindrical case of aluminium metal to prevent the sputtering from other parts of cathode except the surface of target. The anode contains a rectangle stainless steel plate, on which the substrate was fixed. This plate was fixed to isolated bakalite arm. The deposition chamber was pumped with pumping system consists of a mechanical-rotary pump and a diffusion pump. The sputtering deposition processes is achieved with pure argon (99.999%) and a cadmium target of (5cm) for (30min.) under different voltages (3.5, 4.0, 4.1, 4.2, 4.4, 4.6, 4.8)kV., and under different pressures ( , , , , )Torr, with different inter-electrode distances (1, 2, 3, 4, 5)cm. X-ray diffraction spectra of some sputtered films show the hexagonal- closed structure, which belong to the cadmium metal. The experimental results show that the sputtering yield increases with increment of voltage and pressure, and decrease with increment of inter-electrode distance. Maximum deposition rate was (102-105)A°/min. at voltage of (4.6kV), pressure of ( Torr), and at inter-electrode distance of (2cm). In general, transmittance increases with increment of wavelength from (360nm) to (450nm), and shows a rapid increment from (450nm) to (900nm). In general, Absorption coefficient decreases with increment of wavelength from (360nm) to (500nm), and shows a rapid decrease from (500nm) to (900nm). In general, Extinction coefficient decreases with increment of wavelength from (360nm) to (500nm), and shows a rapid decrease from (500nm) to (900nm).

A Study of Cracking Behavior of Epoxy- Polysulphide Blend Using Projectile Technique

By: Hafidh Yousif Abed Saleh    Supervised By: Dr. Najlaa Rushdy Mohammad Alaian    year: 2006

Abstract

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In this research, we studied the cracking behavior of polymeric blend consists of epoxy (EP) and polysulphide (PSR) using projectile technique. We prepared specimens at different weight ratio extended from (0% to 100%). Results have shown that in the increase of the polysulphide in the binary mixture the kinetic energy of the bullet will reduces because of the increase in the energy containment and latter the damage that the target is exposed to will be reduced and the momentum will be less and the number of the circular cracks would increase and the radial cracks which were at high number when the target was made of pure epoxy resin (EP) would decrease. In studying the effect of three basic axes presented in the thickness of the sample, the bullet mass and the distance between the target and the shot gun mouth. it has been concluded that in changing the sample's thickness to (4, 6, 8)mm and the firmness of the bullet mass and the distance it appeared that there is a reduction in the value of kinetic energy of the bullet. In increasing the sample's thickness and the number the circular cracks in the number of radial cracks. But when changing the distance for the dimensions (4, 6, 8)mm it has been observed that there is no impact on the kinetic force of the bullet. In increasing the distance between the gun mouth and the target which is explained on the basis that the increase in the distance led to an equal increase in time and later firmness in speed and energy. When the bullet mass is changed in the value of the kinetic energy was observed and an increase in the number of radial cracks and reduction in the circular cracks. The specimens were photographed by using the using the optical microscope and cracks appeared in these pictures and a test for the hardness for samples mentioned earlier and we have come that increasing the rubber of the polysulphide (PSR) firmness will be lower because in the energy absorbed in the mixture.

Development of Composite Properties Using Unsaturated PolyesterWith Rubber Phase

By: Rafah Alwan Nasif   Supervised By: Dr. Kasim Salman Kasim    year: 2006

Abstract

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Unsaturated polyester resin widely separated because of its low cost and its good physical properties . To get higher impact resistance , it has been blended with nitrile rubber (NBR) , for the weight ratios (UP 70/ NBR 30)% and (UP 80 / NBR 20)% . In another experiment , the first blend was reinforced with (12 %) of glass powder . Some mechanical and physical properties were carried out on these samples like : impact strength , (I.S) , elastic modulus (E) , compressive strength (C.S) hardness , friction coefficient (F.C) , thermal conductivity and diffusion coefficient at different conditions including : natural conditions , and after the immersion in chemical solutions for different periods of time such as (water , H2SO4 acid solution and CaCl2 salt solution ) at different concentrations (0.1,0.2,0.3)N. The results showed that the composite material reinforced with glass powder has showed higher impact strength , Young’s modulus and thermal conductivity and the polymer blend (UP 70 / NBR 30)% has showed higher compressive strength , hardness and friction coefficient With respect to the effect of water and chemical solutions on mechanical properties , the results of this study showed the increase in impact strength values of polymer blend (UP 80 / NBR 20)% after the immersion in these chemical solutions compared with natural conditions . It has found that the polymer blend (UP 70 / NBR 30)% has higher diffusion coefficient in the (0.2)N H2SO4 acid solution while the other polymer blend (UP 80/ NBR 20)% has higher diffusion coefficient in water.

A Study into the Physical behaviour of polymeric and other reinforced blends under the influence of the chemical solutions

By: Zaid Ghanem Mohammed Salih    Supervised By: Dr.Balqees M. D. AL-Dabbagh    year: 2006

Abstract

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This work has been done with using of unsaturated polyester resin mixed with natural rubber (90%-10%) to compose polymeric blend. This polymeric blend is the matrix, which reinforced with several types of reinforcements (Al powder, Al wires, and glass fibers) with a volume fraction of 20%. Hand Lay-up method is used in fabrication of samples of research. Four samples have been prepared: - 1. Blend (Unsaturated polyester + Natural Rubber). 2. Blend reinforced with hybrid (Al wires + glass fibers). 3. Blend reinforced with Al wires. 4. Blend reinforced with Al powder. Several mechanical tests are carried out on these samples, and these are:- Bending test, hardness test, compression test, impact test, creep test, and flexural test. These tests are carried out on samples under the influence of normal conditions (room temperature) and after immersion of all samples in the chemical solutions (KOH, HNO3, and Na2CO3) for 1,2, and 3 months. The normality for all these chemical solutions is 1. Results show that samples of blend reinforced with hybrid (Al wires + glass fibers) possess better mechanical properties of impact strength, creep resistance, and flexural strength at all conditions of tests (room temperature and after immersion in chemical solutions). Moreover, these samples possess better mechanical properties of bending (Young’s modulus) after being immerged in chemical solutions. Samples of blend (Unsaturated polyester + Natural Rubber) possess better mechanical properties of compression strength at all conditions of test. While samples of blend reinforced with Al wires possessed better mechanical properties of bending (Young’s modulus) in room temperature, and hardness after being immerged in chemical solutions. Finally samples of blend reinforced with Al powder possess better mechanical properties of hardness at room temperature. Generally, samples of blend reinforced with hybrid (Al wires + glass fibers) are the better samples in the mechanical tests, while samples of blend reinforced with Al powder are the weakest samples in the mechanical tests. The tests results are affected by all the chemical solutions, but the base solution KOH is the most effective solution.

A Study on Some Physical Properties of PbTe Thin Films

By: Noor S. Sadeq    Supervised By: Dr. Akram .N . Al-Mashhadany    year: 2006

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This thesis studies the prepareation of PbTe alloy and thin films and measurement of its structural, electrical and optical properties. The importance of this comes from the important role that the PbTe plays in IR applications because it has a small energy gap (0.30)eV. PbTe alloy has been prepared successfully in an evacuated quartz ampoule. By x-ray diffraction (XRD)it was found that; the alloy is polycrystalline with cubic structure . The PbTe thin films have been prepared by thermal evaporation from the alloy in a vacuum of (2*10-5)mbar with thickness 500nm at room temperatures and annealed at different annealing temperatures of (373,423,473)K for 30 min. The XRD examination show that PbTe thin films prepared at room temperature and annealed at different temperature are polycrystalline with cubic structure The electrical measurements show that the PbTe thin films have two kinds of activation energy increased with increasing annealing temperature . The Hall effect measurements prove that thin films are n-type at room temperature and convert to p-type by annealing temperature and found that NH decreases with increasing annealing temperature but μH increases with increasing annealing temperature. The optical measurements show that the PbTe thin films have direct energy gap which show that energy gap increases with increasing annealing temperatures and measure the optical constant (refractive index, extinction coefficient and real and imaginary parts of dielectric constant ) which decrease with increasing annealing temperatures.

Effect of Asidic Solutions in Some physical and Mechanical Properties for Epoxy Composites

By: Wurood Mahdi Hameed AL-Askare   Supervised By: Dr. Balkees Mohammed Dyaa AL - dabbagh    year: 2006

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Due to increasing the importance which was occurred in the last year for using composite materials in general and polymers in especial in different advanced industrial applications, so this research come to explaine the important mechanical properties and the effect of aggressive chemical solutions on polymeric composite materials. Epoxy resin type (EP-223)was used as a matrix for composite materials, with iron on the form of wires iron powder and Nylon mat as reinforcement with volume fraction (Vf=30%). Three types of composites were prepared:- (1)Epoxy reinforced with iron wires and Nylon. (2)Epoxy reinforced with iron powder. (3)Epoxy reinforced with iron wires and iron powder. Research subject was implies studying some of mechanical and physical properties for composite materials in different conditions (Natural conditions and Chemical solutions). The chemical solutions which was used in the research were:- Hydrochloric acid (HCl) and Nitric acid (HNO3)with concentration (0.5N),(1N)for each one. Mechanical properties that be studied were:- Young's Modulus (E), Impact Strength (I.S.), Compressive Strength (C.S) and Brinel Hardness (HBr), and also we were studied physical properties which were:- Thermal Conductivity, Dielectric (D.C.)and also Absorption test for all prepared composite materials with calculating diffusion coefficient by immersing them for a period of time in chemical solutions. In natural conditions, composite material reinforced with iron powder showed the highest value of young's modulus(8.6716 GPa), hardness (19.3873).Hybrid composite material reinforced with(iron wires and nylon) showed the highest value of impact strength (58.1170 KJ/m2) and compressive strength(111.209 MPa), while the highest value of thermal conductivity was for hybrid composite material of iron powder and wires (0.6319 W/m.oC). On the other hard, and concerning the study of mechanical and physical properties and absorption test for composite materials which were immersed in chemical solutions, have recored contrasty results from one material to another.

Study of The Effect of Doping on Structural, Optical and Electrical Properties of (ZnS) Thin Films Prepared by Chemical Spray Pyrolysis

By: Adnan M. M. Al- Saedi   Supervised By: Prof. Dr. Alaa A. Al- Naimi   year: 2005

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In this research thin films of (ZnS) have been prepared as pure and doped by Aluminum (Al), Copper (Cu) and Nickel (Ni) with different ratio (i.e 2% , 5%), the films were prepared by chemical spray Pyrolysis from zinc chloride (ZnCl2) and thioriaa (CS(NH2)2) at substrate temperature (583K). The structural properties of thin films were studied by using reflective optical microscope and x-ray diffraction. Were appeared that the thin films have polycrystalline structure type (Zincblende) and the doping processes did show obvious effect on crystal structure of (ZnS) films doping with (Cu and Ni) where became near from amorphous structure, also calculated the lattice constant (a) and its values decreased after doping process. From studying of optical properties for range of wave length (300-900nm), the transmission were (75-85%), where doping process did show decreases in transmission of thin films because extinction increasing in radiation intensity after doping. Also calculated the optical constant such as absorption coefficient (), extinction coefficient (K) and energy gap (Eg) for direct electronic transitions where value equal to (3.42eV) before doping and between (3.38-3.02)eV after doping depending on material and concentration doping. Finally, the electrical properties for all films were studied through variation of resistively () with temperature for range (303-413)K and calculated the electrical conductivity () and activation energy (Ea). As a result of the doping process the conductivity was increased but the activation energy was decreased, from Seebeck effect investigations showed all films were of (n – type), and from the measurements of the activation energy of electro-thermal power (Es) that the its values was increased after doping and from it calculated the activation energy of mobility (E) where equal to different between (Ea) and (Es).

Synthesis of indium oxide thin film by DC- Sputtering for gas sensing applications

By: Noor Malik Saadoon Al-musawi    Supervised By: Dr.Saryia D.M AL-Algawi and Dr. Selma M.H Al-Jawad   year:2014

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In this project In2O3, ITO/ Si gas sensor were fabricated by an efficient and size – controlled. Many parameters have been study to proved the optimum conditions,(annealing temperatures, and doping concentration). Structural, optical and electrical properties of In2O3 thin films were investigated and analyzed extensively under different conditions. Structure and surface morphology of In2O3 thin films were characterized by X-ray diffraction. Atomic Force Microscope and Scanning Electron Microscopy measurements. Annealing was in air at different temperatures of (300,400,500) ̊ C and at constant time (60 min); the XRD technique that showed these films is polycrystalline structure with a preferred orientation of (222),( 440),(400) the best orientation plain is (222). These been found crystalline size increases with increasing annealing temperature and decrease with increasing doping concentration. The optical properties of In2O3, ITO thin films were studied such as transmissions, extinction coefficient, absorption coefficient and optical energy gap .The transmittance was measured in the wavelength range from(300nm to 900 nm) for all the films was highly transparent (greater than 85%). The optical energy band gap was increased with the annealing temperature in range from (3 to 4.9) eV, and increase with doping concentration in range from (3.9 to 4.15) eV. The electrical properties for In2O3 ,ITO thin films include D.C electrical conductivity and Hall effect which shows that the type of films is (n- type), and the film has two activation energies for pure and doped films in the rang (305-355)K, the resistivity decreases with increased annealing temperature. And resistivity increase with doping concentration at 8wt%. The sensitivity toward NH3, NO2 gas has been measured.In2O3 doped with (Sn) has higher sensitivity than that of pure for NH3, The sensitivity toward, NO2 gas has been measured, where In2O3 doped with (Sn) has higher sensitivity to NO2than to NH3.

Preparation and Antibacterial Activity of Ag and TeO2 Nanoparticles Produced by Laser

>By: Thamir Hassen Ali   Supervised By: Dr. Abdulhadi Kadhim AL-Ogaili and Dr.Abdulrahman K. Ali   year: 2014

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In this work preparation, and characterization of Silver and Tellurium nanoparticles were they synthesized by pulsed (Q-switched, 1064 or 532 nm doubled frequency-Nd: YAG) laser ablation of silver and Tellurium dioxide which cut into 10 mm x10 mm , cleaned and then immersed in double distilled and deionized water as a depth of 8mm, without any chemical additives. Different techniques such as X-ray Diffraction (XRD), UV-Vis spectrophotometer, Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM) were used to study the structural and morphological properties of Ag and TeO2 nanoparticles. The effect of laser parameters such as laser energy, number of pulses and wavelength on the properties of nanoparticles were studied. It has been observed that laser energy, wavelength and number of laser pulses have a control over the size of the nanoparticles. The increasing of laser energy and number of pulses shows a clear blue shift in the absorption peak of fabricated nanoparticles indicating that the average size of the particles decreases with increasing of laser energy and number of pulses. Ablation for a longer period reduces the average size of nanoparticles which is attributed to the re-ablation of fabricated nanoparticles. The concentration of ablated Ag and TeO2 NPs with different numbers of laser pulses was obtained via Atomic Absorption Spectrometer (AAS); however it was found that the concentration of NPs increases linearly when the number of laser pulses increases. The average particle size was measured by scanning electron microscope and it was found to be between 166 nm to 151.8 nm for Ag NPs and 38 nm to 42 nm for TeO2 NPs. The relation between the ablation efficiency and wavelength varies with laser fluence and it can be noticed that the ablation efficiency at 532 nm has higher value at low fluence, while the ablation efficiency at 1064 nm has higher value at high fluence. These findings will be discussed in terms of the self-absorptions of the incident laser light by colloidal particles. The morphology of nanoparticles was studied as a function of laser wavelength and it's found that the average roughness varies with laser wavelength. Also the antibacterial effect of synthesized silver and TeO2 NPs was studied against four pathogens namely S. mutnas, S. aureus, P. mirabilis and E. cloacae. The activities of nanoparticles against the different bacteria were compared with the activities of four antibiotics such as amoxicillin, streptomycin, chloramphenicol and penicillin. It was found that the inhibition zone of bacteria by TeO2 nanoparticles has comparable results with antibiotics while Ag nanoparticles do not show such activity.

Design and Construction of IPL System for Medical Applications

By: Hussein Ali Shakir   Supervised By: Prof. Dr. Waleed K. Hammoodi and Assist. Prof. Dr. Raid A. Ismail    year:2014

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Intense pulsed light, commonly abbreviated as IPL, is a technology used by cosmetic institutions and medical practitioners to perform various skin treatments. The technology utilizes Xe flash lamps to produce intense pulses of polychromatic and incoherent light, and to deliver them directly to target skin chromophores. The modifiability of several parameters; such as, wavelength, fluence, pulse duration, and pulse delay is of a great advantage for IPLs. In this study, the theory of the Xe flash lamp system was analyzed in order to design a flash lamp system. In addition, some experimental trials on different pulse durations and energies were carried out. Also, various flash lamp driving circuits were built up and tested on various Xe flash lamps. This was achieved by constructing a single and multiple-mesh pulse forming networks; using different types and values of inductance and capacitance circuits. The current discharge profile through the Xe flash lamp was measured by either an AT-C403 current probe or inserting a 70 mΩ resistor in series with the lamp. The output of the flash light was detected by using a reversed biased Si-photodiode. All optical and electrical measurements were recorded and stored on a digital storage oscilloscope. The results obtained showed a light pulse profile follows the exciting current pulse, meaning that the light pulse length is usually equal or slightly shorter than the current pulse duration. Any increase in the current pulse duration has led to an increasing of the pulsed light linearly.

Denture Base Modification by Reinforcement of Carbon Fiber/ Hydroxyapatite and Study its Properties

By: Russel Rushdi Ghanim   Supervised By: Assist. Prof. Dr. Sewench N. Rafeeq and Assist. Prof. Dr. Wafaa A. Hussain    year: 2014

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This study includes two steps for the preparation of acrylic denture base composite. The first step is carbon fibers coating and the second step is the reinforcement of denture base material. Sol-gel technique has been used to coat carbon fibers with calcium phosphate to improve the esthetic of black carbon fibers as it's biocompatible. To improve bonding between carbon fibers and prepared calcium phosphate powders, the surface of carbon fibers has been treated with para-aminobenzoic acid. The mechanical tests in this study include: (impact strength, flexural strength and surface hardness). According to the results obtained in this study, the mechanical properties of denture base resin have been considerably enhanced by reinforcement with uncoated and coated carbon fibers. The structural tests include: (SEM, XRD, AFM and FTIR). The morphology of the coating layers has been examined by scanning electron microscope (SEM). The crystallized phase composition of coatings has been identified by x-ray diffractometry (XRD). The grain size of dried and heat treated calcium phosphate coat has been estimated by atomic force microscope (AFM) and fourier transform ــ infrared spectroscopy (FTIR) analysis which support and verify the x-ray diffraction findings.

Preparation and Study of SnO2 Nanoparticles Properties for Optoelectronic Applications

By: Ali Jafar Hadi   Supervised By: Dr. Uday Muhsin Nayef   year: 2014

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In this work, colloidal SnO2 nanoparticles were prepared by using laser ablation of tin target immersed in different solvents (double deionized water, methanol and ethanol) without the use of any chemical/surfactant. This method is a promising technique for the fabrication of various nanomaterials and simply controlling the experimental parameters. The effects of solvents, laser fluence and number of pulses on the morphology, chemical, optical and electrical properties, of the synthesized nanoparticles were studied. X-ray diffraction shows that the structure of SnO2 NPs film is polycrystalline with preferential orientation in the (101) direction. Morphological properties were observed by TEM for particle size and shape. The SnO2 particles had an almost irregular shape with a mean diameter in water between 12 to 20 nm. Other solvents showed much larger particles with almost spherical shape. Particle size of SnO2 NPs observed by AFM images as a film deposited on glass slides, showed good agreement with the TEM results. The Fourier transform infrared spectroscopy (FTIR) spectrum showed a band in the range of 600–700 cm-1, assigned to Sn–O antisymmetric vibrations. The UV–Visible absorption spectra refer to sharp absorptions in the ultraviolet (UV) region. An increase in absorption peaks with the reduction in particles size was noted. The behavior of the UV–Visible spectra associated with the SnO2 nanoparticles was studied as a function of laser fluence, number of pulses and solvents. The optical band gap of SnO2 nanoparticles suspensions was between 4.14 to 4.32 eV in water solution, 4.12 to 4.26 eV in methanol solution and 4 to 4.13 eV in ethanol solution as when using different laser fluence and different number laser pulses. Hall Effect measurement of the SnO2 NPs suspensions prepared in different solvents showed them as n-type. Hall coefficient sign has not been changed with solvent type when preparing of the SnO2 NPs indicating electrons charge carriers. The electrical properties of the structure Al/SnO2 NPs/PS/c-Si/Al showed large increase in resistivity, more than the structure Al/SnO2 NPs/c-Si/Al because of the increase in depletion region width.

Fabrication and Characteristics Study of ZnO NPs/Si Solar Cells

By: Nabaa Hussein Alawi    Supervised By: Dr. Selma M.H. Al –Jawad and Dr. Raid A. Ismail    year: 2014

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In this project ZnO NPs / Si solar cells were fabricated by an efficient and size –controlled three-step method which consists of : (1) oxidation of metallic zinc (Zn) in hydrogen peroxide (H2O2) solution ,(2)spraying of the solution formed in step 1 onto substrates to form precursor films , and (3) oxidation of the precursor films in the air to form ZnO NPs films at different temperatures (100-500)0C . The structure of the nanoparticles films was investigated by X-ray diffraction (XRD) which indicates that ZnO NPs are in wurzite structure along (100) plane with particle size in the rang of(16.06-28.28)nm. The morphology of the nanoparticles films was studied by atomic force microscopy (AFM) which indicates that the average grain size of ZnO NPs is in range of (63.77-95.86)nm and the surface roughness increases as oxidation temperatures increase . The photoluminescence (PL) properties showed three peaks at ultraviolet , violet and green emission regions with shifting at ultraviolet emission region to longer wavelength . The band gap is found to be within the range of (3.85-3.96)eV . The ZnO NPs has n-type conductivity and the mobility was in the range of (5-22) cm2.V-1 .s-1. The electrical properties C-V and I-V of n-ZnO NPs /Si indicate that ZnO NPs /Si is abrupt heterojunction type . The saturation current decreases as oxidation temperatures increase . It was found that ZnO NPs/Si solar cells have maximum efficiency of 6.796% and VOC=0.379 V, JSC=25 mA/cm2 ,Jm =20 mA/cm2 ,Vm =0.340 V and FF=0.725 .The spectral response of ZnO NPs /Si solar cells showed three response regions and the maximum value was at 0.621mA/W at λ= 800 nm .

Surface Modification of Brass and Al Alloys by Laser Shock Waves

By: Saeed Mcheet Feyadh Al-Janabi   Supervised By: Dr.Abdulhadi Kadhim Judran    year: 2014

Abstract

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Laser shock processing (LSP) was performed on brass and 2024-T3 Al alloys specimens to reveal its effect on microstructure and mechanical properties. LSP experimental array is as follows, A convergent lens is used to deliver 0.5-1J/pulse (1064 nm) and in a 10 ns laser pulse produced by Q-switched Nd:YAG laser with spots of a 0.5-2 mm in diameter moving forward along the workpiece at pulse density of 500 pulses/cm2. Water is used as the transparent confining layer and the non-prate black paint with a thickness of 20±2 µm is used as an absorbing layer. First, the effects of the LSP parameters as laser spot size, laser pulse energy and thickness of water layer on the surface micro-hardness and roughness were investigated. The experimental results show that, the surface roughness increases and the high micro-hardness would be generated near the surface due to LSP. The spot size decrease caused increase in surface roughness and micro-hardness due to increase in laser shock pressure. The surface roughness and micro-hardness increase with laser pulse energy increase. The optimum thickness of water layer was 3mm. Second, at the optimum values of 1mm spot size, 1J pulse energy and 3 mm water layer thickness, LSP effective parameters, microstructure and mechanical properties were evaluated. Microstructure and mechanical test include surface morphology by SEM, grain analysis by AFM, micro-hardness depth distribution, wear resistance, fatigue resistance and corrosion resistance. Results show that LSP impact has some thermal effects at the metal surface, it can refine grains and induce compressive residual stresses at depth of 0.8 mm. LSP impact can improve the wear resistance of brass and 2024-T3 Al, where the wear rate is reduced by 79% for brass and 67% for 2024-T3 Al compared with the untreated LSP specimens due to work hardening and compressive residual stress of LSP impact.. The results demonstrate that the LSP can improve fatigue resistance for brass and 2024-T3 Al alloys. By comparing with the untreated specimens, the fatigue lives of the specimens after LSP were obviously increased by 64% for brass and 73% for 2024-T3 Al at lower stress level due to the compressive residual stresses near the surface. Effects of LSP on electrochemical corrosion resistance of brass and 2024-T3 Al in 3.5 wt.% NaCl were investigated. Results show that the corrosion resistance with LSP impact is improved. The polarization resistance of brass and 2024-T3 Al is increased by more than five times compared with untreated LSP samples.

Preparation of porous ceramic by Consolidation casting method

By: Hazim Khyoon Alag   Supervised By: Assist. Prof. Dr. Wafaa Abdul Al-Khalik Hussein   year: 2013

Abstract

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Consolidation casting method has been successfully used to produce porous ceramics at low producing cost. In this work, porous calcium phosphate (CaP) ceramics have been produced by using natural additives (ovalbumin and albumin) proteins and (corn and rice) starches with (0, 5, 10, and 20) wt%. The mixture of proteins and calcium phosphate powder were dried at 60oC for 12 hours, while the mixture of starches and calcium phosphate powder were dried at 80oC for 2 hours. These samples were sintered at different temperatures (1100, 1200, 1300, and 1400oC). Many mechanical and physical tests were used to determine the properties of the prepared ceramic material which involved the linear shrinkage, water absorption, apparent porosity, compressive strength, scanning electron microscope SEM, and X-ray diffraction. The results showed that the types of additive affect the physical and mechanical properties of the ceramic produced. The water absorption and apparent porosity have been found to decrease with increasing sintering temperature, but the linear shrinkage and compressive strength has been found to increase with increasing sintering temperature of calcium phosphate mixture. Moreover, the increasing in compressive strength revealed an increasing in the evaluated properties. The linear shrinkage, apparent porosity, and water absorption showed an increase with increasing binder's content of calcium phosphate mixture for all binders, except for the ovalbumin has been decreased with increasing binder's content.

Deposition InAs Nano film and Studying some of the Physical Properties

By: Rana Kadum Abd-Alnabi   Supervised By: Ali M. Mousa Al - Zuhery   year: 2013

Abstract

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Practically all material changing into nano as long as their grain radius become smaller than Bohr radius. InAs semiconductor having the second large Bohr radius and having also a small band gap which makes us choosing as a material for our study. To deposited nanoInAs spray pyrolysis was adopted since it is cheap and gives the possibility of controlling thin films characteristics. In this work a three principle parameters was studied, the first is spraying time, the second was the substrate temperature and the third was the solution morality in order to determine the best deposition conditions which could be used in making hetrojunction Measurement emerged that the crystal structure of thin films change significantly with change spray parameter on the optical and electric properties ,where describes the X-Ray schemes that all films were multiple crystal and levels of crystalline most frequent and highest intensity levels were(111) and (200) at the diffraction (25.442)°and (29.442)° respectively In addition to this was the expense of some structural characteristics such as grain size, strain, micro strain and the lattice constant. Thickness increased linearly with increasing temperature, while decreasing thickness at temperature higher than 300 C°,as well as thickness increased linear with increasing spray time. Analysis of transmittance and absorbance spectrum, using UV-VIS spectroscope at range(200-1100)nm was to increase thin films impact on those properties where there is no permeability spectral the region of at least 300nm, and then show a sharp increase in permeability and stabilizes after 400nm at temperature 250C° and 270C° and at higher temperature less permeability. Repeated the same results at different times of spraying. As the spectral absorbance it show quantitavely exclusively of energy gap at 300nm wavelength. And repeated the same energies at different spray time. Energy gap was greater than the value in mass situation and decreases with the spray time and temperature of substrate An addition, the increase in temperature deposition led to increased electrical conductivity, as to the results of the adoption of connectivity on the spray time also found that the conductivity increases with spray time.

Preparation and Characterization Study of Titanium Dioxide Thin Films for Gas Sensor Application

By: Zahraa Yassir Abbas   Supervised By: Dr. Selma Mohammed H. Al -Jawad   year: 2013

Abstract

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In this work TiO2 thin films were prepared by using spray pyrolysis technique ,which is a simple and inexpensive technique suitable for large deposition area. Many parameters have been considered in this study to specify the optimum condition ,namely (annealing temperatures , annealing time and doping). Structural,optical and electrical properties of TiO2 thin films were investigated and analyzed extensively with different conditions. Structure and surface morphology of TiO2 thin films were characterized by X-ray diffraction ,Atomic Force Microscope and Scanning Electron Microscopy measurements. Annealing in air at different temperatures of (450,500,550 and 600) ̊ C at constant time (90 min),also for different time of (60,90 and 120) min at constant temperature (550̊ C) was achieved. X-ray analysis has confirmed the formation of anatase phase with slight increases in crystaline size ,with increasing annealing temperature and annealing time . Effect of doping with chromium on structure and surface morphology, optical and electrical properties was studied.The X-ray diffraction indicates that all the grown films show the anatase phase with decrease in crystaline size with increasing of doping concentration. As a result, it has been found that films structure and properties strongly depend on doping concentration . The optical properties of TiO2 thin films were studied such as transmittance, extinction coefficient, absorption coefficient and energy gap for different parameters (annealing temperatures , annealing time anddoping).The transmittance was measured in the wavelength range from(300nm to 1100 nm) for all the films. The optical energy band gap was increased with the annealing temperature and time in range of (3.1 to 3.5) eV,while decreas in optical energy gap with increase in doping concentration in range of (3.5 to 3.2) ev. The resistivity decreases with increasing annealing temperature , annealing time and doping concentration. Hall measurements indicate that the TiO2 thin films of n- type semiconductors for different parameters. The sensitivity toword NH3 gas has been measured ,whereTiO2 doped with (Cr) has a sensitivity higher than pure.

Synthesis and Characteristic Study of Nanostructured (PbS/n-Si) by Chemical Bath Deposition

By: Suad M. K. Al-Shammari   Supervised By: Dr.Ali M. M. Al-zuhery and Dr.Selma M.H.Al-Jawad   year: 2013

Abstract

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In this work nano PbS films were prepared using chemical bath deposition technique, which is a simple, inexpensive and suitable technique for large deposition area. Lead acetate salt was used as a source of lead ions and thiourea as a source of sulfide ions. During deposition several growth parameters have been considered in this work to specify the optimum conditions, namely (deposition time, temperature of path solution, pH value, lead ion concentration and thiourea ion concentration).The structure, optical and electrical properties of nano PbS films were investigated and analyzed extensively for a variety of growth conditions. The structural characteristic of the films prepared on a glass substrates have studied using X-ray diffraction, results shows that all the films were polycrystalline cubic structure for all deposited films under different growth conditions. The electrical properties of these films were studied. The d.c conductivity for the deposited films increases from 4.1*10-6 to1.5*10-5(.cm)-1 with thickness increases. From study of the electrical conductivity with temperature the films shows two activation energies Ea1 and Ea2 which are decrease from 0.567 to 0.351 eV and from 0.302 to 0.119 eV with thickness increases. Hall measurements showed that all the films are p-type and carrier concentration increase from (4.4 3 * 1015 to 2.5* 1016) cm-3 with thickness increase. Also we observed that the mobility were decreases with increasing of thickness. Optical measurements (transmission and absorption) were carried out. Transmittance decreased with increasing the deposition time, temperature of solution and pH value, while the transmittance increased with increasing lead ion concentration.The direct optical energy band gap range was between (1.68 -2.4) eV. Nano crystalline PbS was deposited on the n- type silicon to study and characterize the heterojunction. The I-V characteristics of the PbS/n-Si heterojunction have been studied,where the current-voltage characterization under dark conditions shows that forward bias current variation exponentially with voltage bias. Under illumination, the photocurrent density decreases with increase of deposition time. The reverse bias capacitance for PbS/n –Si heterojunciton was measured as a function of bias voltage at the frequency 200 KHz, and it is indicated that these heterojunction are abrupted. The capacitance decreases with increasing the reverse bias voltage. High spectral responsivity of 0.44 A/W, quantum efficiency 80% , and specific detectivity 1.98 * 1011 cm Hz1/2 W-1 where obtained. Also the shape of the spectrum of nano PbS/n -Si is extended into the blue region, due to widening of the window band gap.

Structural and Dielectric Investigations of Al-doped Nano Nickel Ferrite

By: Shahad Humam Sulaiman   Supervised By: Asst. Prof. Dr. Salam H. Ali Al-Hadad   year: 2013

Abstract

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In this work the preparation of NiFeAlO4 nano ferrites samples, were synthesized by using sol-gel auto combustion method at temperature about 200°C. Then pelletized and sintered at different temperatures (900, 1000, 1100 and 1200°C). The formation of inverse spinel structure and inherent properties of high electrical resistivity, dielectric losses and high density material. The present work focused on studying the structural and electrical properties of NiFe2-xAlxO4 , where (x=0, 0.2 ,0.4, 0.6, 0.8, 1, 1.2, 1.4) using many analysis’s like x-ray diffraction ,LCR meter, FTIR and AFM. The results show that the chemical composition has a major effect on electrical, structural, and physical properties. Crystalline ferrite nano- powders and grains were synthesized with (19-22.6 nm) nano-sized particles, and (34-52 nm) nano-sized sintered grains. The phase analysis done by x-ray diffraction method confirmed the formation of the expected ferrites structure, where lattice parameter and crystallite size were increased but the x-ray density was decreased when increasing the Al content in NiAl ferrites. Resistivity of all samples have been measured at temperatures in the range of (300-540)K and found to decrease with the increasing of temperature this behavior is the same as in semiconductor, and resistivity and temperature diagram was used to calculate the activation energy. The FTIR spectra of NiFeAlO4 were charted in the range of 500 cm-1 to 4000 cm-1 FTIR Spectrum of different compositions in the series. However a shift in the peak positions and intensity was observed. Either in the examination of AFM noted that the grain size and roughness were increased with oxidation temperature. The dielectric properties were measured using (LCR) meter in the frequency range of (100 KHz – 6 MHz). Dielectric constant (εr'), the loss tangent (tanδ) and the loss factor (εr′′) were calculated from capacitance data. The dielectric parameters decreased with the increase of the frequency. This behavior is typical of ferrite materials as explained by Koop’s model. The result also showed that the Conductivity and dielectric loss increased with the increase of the Al content for NiAl ferrite, while conductivity and dielectric constant decreased with the increase of the amount of Fe ion for NiAlFe -ferrite. The resistivity of samples were found to increase the amount of Fe batter than the models of sintered samples.

Study of Physical Properties of CdZnS Ternary Thin Films Prepared by Chemical Bath Deposition

By: Fadheela Hussen Oleiwe   Supervised By: Dr. Selma Mohammed H. Al -Jawad   year: 2012

Abstract

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In this work, a series of Cd1-xZnxS 0.05 ≤ x ≤ 0.7 ternary thin films were prepared on glass substrates using chemical bath deposition (CBD ) method. An attempt was made to modify the band gap of CdS (2.4 eV) by preparing a mixed lattice with a high band gap material, ZnS (3.7 eV), giving a new set of materials. Cadmium sulphate, Zinc sulphate, and thiourea are used as the basic source materials in the deposition bath. Many growth parameters have been considered in this study to specify the optimum condition, namely (temperature of solution, pH, and deposition time) for properties Cd0.5Zn0.5S thin film. Structural, optical and electrical properties of Cd1-xZnxS thin films are investigated and analyzed extensively with respect to growth conditions. The Cd1-xZnxS films are annealed in air at temperatures (300) ºC at constant time of ( 60 min). Structure and surface morphology of Cd1-xZnxS thin films were characterized by X-ray diffraction (XRD), Atomic Force microscope (AFM), Optical Microscopic, and Scanning Electron Microscopy (SEM) Measurements. The XRD indicates that all the grown films show only one diffraction peak located at (2θ= 26.7°) with hexagonal structure in predominant (002). The average grain size changes from (9.3nm to 4.48nm) with the increase in Zn- content (x = 0 to 0.65). It was found that as the Zn- content increases, the peak intensity decreases and for (x ≥ 0.7) the films have amorphous character. The values of lattice constant ‘a’ and ‘ c’ have been observed to vary with composition from (5.75 nm to 4.68 nm) and (6.66 nm to 6.62 nm), respectively, with the increase in Zn- content ( x = 0 - 0.65) . The AFM studies showed that the smooth surface texture was observed in the deposited Cd1-xZnxS films with (x= 0.3) , the surface roughness of the Cd1-xZnxS thin films is about ( 2.66nm to 9.47nm) and the root mean square (RMS) is about ( 3.41nm to 11.9nm) with increase in Zn- content (x = 0.3 to 0.6) .The optical microscopic measurement observes that films surface become increasingly coarse at increasing the Zn- concentration. The SEM exhibits that grains in the film are distributed to cover the surface of the substrate completely, the grains become small in diameters with increasing Zn-contents. The optical properties of Cd1-xZnxS thin films were studied by the transmittance, absorption coefficient and energy gap for deposition conditions (80ºC temperature pH= 10 and time 3h). The transmittance is measured in the range from ( 300 nm to 900 nm) for all the films, in the visible wavelength region, the average transmittance greater than (80 %) at Zn-content (x = 0 to 0.7). The Cd1-xZnxS thin films have high optical absorption coefficients where the value reaches at (1.2×105 cm-1). The energy band gap ( Eg) values of Cd1-xZnxS thin films are ( 2.4 eV to 3.4 eV) corresponding to the Zn-content ( x = 0 to 0.7) respectively. In other word, the optical band gap of Cd1-xZnxS thin films become wider as Zn-content increases. All the Cd1-xZnxS films show that the resistivity varied in the range ( 0.45× 103 Ω.cm to 5.9× 103 Ω.cm) corresponding to the Zn-content (x = 0 to 0.7), respectively. Also the activation energies Ea1 (0.124 eV to 0.833 eV) and Ea2 (0.063 eV to 0.277 eV) varied with the increasing Zn-content (x) in the films (x = 0 to 0.7). Hall measurements indicate that the Cd1-xZnxS thin films have same conduction type (n-type) conductivity. The carrier concentration and mobility values for Cd1-xZnxS thin films vary with zinc content , furthermore their values are (5.201× 10¹² cm-3- 1.263× 1012cm-3) and (140.5 5 cm2V-1S-1 - 22.435 cm2V-1S-1 ) respectively.

Synthesis and Characteristics Study of ZnO/Porous Si Hetrojunction

By: Mohammed Waleed Muayad    Supervised By: Dr.Uday Muhsin Nayef   year: 2013

Abstract

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In this project, porous silicon preparing by electrochemical etching (ECE) technique using different parameters such as silicon orientation ((100) & (111)), etching time (5, 10, 20 & 35 min), current density (10, 20, 30 & 40 mA/cm2) and HF concentration (15%, 20% & 30%). And next step of project was deposition of ZnO thin film on glass by spray pyrolysis technique from Zinc nitrite and study the effect of changing thickness of ZnO film (100, 200, 500 & 800 nm). And the final step of project consist deposition ZnO film on PS. The measurement refer with nano- structure (mesoporous silicon), the PS (100) gives the characteristics of nanoscale better than directional silicon (111) due to the crystal structure and the different in interaction between the HF electroyied and silicon. And The measurements of ZnO refer n-type semiconductor with hexagonal structure (polycrystalline structure) and this structure helps to emit several wavelengths from ZnO, also the decreasing of ZnO thickness leads to increasing in energy gap due to decreasing in grain size . And when when ZnO was deposited on PS the properties of both ZnO and PS will improved, where the structure properties showed the deceasing in crystal size with good adhesion between ZnO and PS. Morphology showing crystalline regularity and growth of ZnO film and improving of structural stability of the PS substrate. Optical measurement (PL & R%) shows increasing in absorption of light with increasing in blue shift of PS and increasing in UV emission of ZnO film, Raman measurement show quantum confinement in PS layers with decreasing in variation mode of ZnO film, and the electrical properties of ZnO/PS show large increasing in resistivity come from increasing in depletion layer of the sponge structure of Al/ZnO/PS/c-Si/Al .

A Study on the UV-Visible Plasma Emission from Al and Fe Targets Produced by a Q- Switched Nd: YAG Laser

By: Mustafa Mohammed Ridha Sabhan AL-Wiealy   Supervised By: Asst. Prof. Dr. Sabah Habeeb Sabeeh and Dr. Naseer Mahdi Hadi   year: 2013

Abstract

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The present work concerned the study of pulsed plasma generation by a 6 ns Nd: YAG pulsed laser at 1064 nm wavelength with a maximum pulse energy of 500 mJ focused rough on Al and Fe solid target samples in air at atmospheric pressure and vacuum. The emitted spectrum from the plasma plume was in the range of [300–750] nm and was recorded using a monochromator and Silicon Photo Detector (PD). Measurements of electron temperature and electron density of the produced plasma at different laser energies and at different vacuum pressures are described using different emission spectral lines. Plasma diagnostics are based on optical emission spectroscopy and Local Thermodynamic Equilibrium (LTE) assumption. Excitation temperature of plasma is determined from the Boltzmann plot. Temperature of Al plasma at atmospheric pressure was 1eV (11600 Kº) and at vacuum pressure was 1.22 eV (14144.9 Kº). Temperature of Fe plasma at atmospheric pressure was 1.466 eV (16997.1 Kº) and at vacuum pressure was 1.711 eV (19837.6 Kº). The electron density was determined from the FWHM of the Stark broadening. The electron density for Al plasma at atmospheric pressure was 7.0×1018 cm−3 and at vacuum pressure was 7.5×1018 cm−3. The results of the electron density for Fe plasma at atmospheric pressure was 8.2×1018 cm−3 and at vacuum pressure was 9.0×1018 cm−3. Also the results show a maximum value of electron density at delay time of 5.5µs after laser pulse. Also the results show intensity thresholds for Al plasma, and the saturation at laser energy of 420 mJ. Also the results show intensity thresholds for Fe plasma and the saturation at laser energy 500 mJ.

Deposition InAs Nano film and Studying some of the Physical Properties

By: Rana Kadum Abd-Alnabi   Supervised By: Ali M. Mousa Al - Zuhery   year:2013

Abstract

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Practically all material changing into nano as long as their grain radius become smaller than Bohr radius. InAs semiconductor having the second large Bohr radius and having also a small band gap which makes us choosing as a material for our study. To deposited nanoInAs spray pyrolysis was adopted since it is cheap and gives the possibility of controlling thin films characteristics. In this work a three principle parameters was studied, the first is spraying time, the second was the substrate temperature and the third was the solution morality in order to determine the best deposition conditions which could be used in making hetrojunction Measurement emerged that the crystal structure of thin films change significantly with change spray parameter on the optical and electric properties ,where describes the X-Ray schemes that all films were multiple crystal and levels of crystalline most frequent and highest intensity levels were(111) and (200) at the diffraction (25.442)°and (29.442)° respectively In addition to this was the expense of some structural characteristics such as grain size, strain, micro strain and the lattice constant. Thickness increased linearly with increasing temperature, while decreasing thickness at temperature higher than 300 C°,as well as thickness increased linear with increasing spray time. Analysis of transmittance and absorbance spectrum, using UV-VIS spectroscope at range(200-1100)nm was to increase thin films impact on those properties where there is no permeability spectral the region of at least 300nm, and then show a sharp increase in permeability and stabilizes after 400nm at temperature 250C° and 270C° and at higher temperature less permeability. Repeated the same results at different times of spraying. As the spectral absorbance it show quantitavely exclusively of energy gap at 300nm wavelength. And repeated the same energies at different spray time. Energy gap was greater than the value in mass situation and decreases with the spray time and temperature of substrate An addition, the increase in temperature deposition led to increased electrical conductivity, as to the results of the adoption of connectivity on the spray time also found that the conductivity increases with spray time.

Synthesis and characterization of magnesium ferrites material

By: Ghead Kalaf Salman    Supervised By: Asst. Prof. Dr. Sabah Mohammed Ali Ridha    year: 2012

Abstract

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In this work preparation NiZn and NiZnMg nano ferrites samples , using sol-gel auto combustion method at temperature about 2000C, then pelletized and sintered at different temperatures (1273, 1373 and 14730k).They have showed spinel structure and inherent ‎properties of high electrical resistivity, low electrical losses and high ‎density material. Therefore, these ferrites have a potential candidate for high frequency applications The present work is study the electrical and structural ‎properties of Ni1-xZnxFe2O4 and Ni0.7-yZn0.3MgyFe2O4, where (x=0, 0.1, ‎‎0.2, 0.3) and (y=0, 0.1, 0.2, 0.3) respectively, and shows effect of chemical composition ‎on electrical, structural, and physical properties. Crystalline ferrite nano- powders and grains were successfully synthesized and the ‎process has resulted in the formation of (19-22.6 nm) nano-sized particles, and (34-52 nm) nano-sized sintered grains. Chemical phase analysis carried out by x-ray diffraction method ‎confirms the formation of the expected ferrites structure, where lattice parameter and crystallite size increase but the x-ray density and porosity ‎decreased when increasing the Zn content in NiZn ferrites. Also the same behavior takes place when Mg content increases in NiZnMg-ferrites. Resistivity of all samples have been measured at temperatures in The range of ‎‎ (300-540) K0 and found it decreases with the increasing of temperature like ‎a semiconductor, and resistivity and temperature were used to calculate the ‎activation energy. Activation energy results showed decreases when increase the Zn content in NiZn ferrites. Resistivity and activation energy both are increasing with high concentration of Mg ions. The dielectric properties are measured using (LCR) meter in the frequency ‎range of (100 Hz – 200 kHz), dielectric constant (εr'), the loss tangent ‎‎ (tanδ) and the loss factor (εr′′) are calculated from capacitance ‎data, that the dielectric parameters decrease with increase of the ‎frequency.‎ model. This behavior is typical of ferrite materials as explained by Koop’s model. Conductivity and dielectric loss were increased ‎with the increase of the Zn content for NiZn ‎ferrite, while conductivity and dielectric constant were decreased with increase the ‎amount of Mg ion for NiZnMg -ferrite.‎ Found the resistivity of samples increase the ‎amount of Mg batter than the models of sintered samples.

Fabrication and Characterization of Porous Silicon Photovoltaic Devices

By: Ayoub Hassan Jafar   Supervised By: Ayoub Hassan Jafar   year: 2012

Abstract

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Porous silicon (PS) layers have been prepared in this work by electrochemical etching (ECE) technique of a (111) p-type silicon wafer with resistivity (1.5-4 Ω.cm) in hydrofluoric (HF) acid of 20% concentration. Various affecting parameters were studied such as the current density (10, 20, 40, and 50 mA/cm2), and etching time (10, 20, and 40 min). We have studied the optical properties (Reflectivity), vibration properties (Raman), surface properties (FTIR), structural properties (XRD), morphological properties (AFM), and electrical properties (I-V, C-V, photocurrent, and photosensitivity). Also we prepared PS layers by ECE for p-n silicon at different current densities (5, 10, and 40 mA/cm2) with fixed etching time at 20 min, in 20% HF acid, in order to study the photovoltaic measurements for solar cell. The PS surface showed lower reflectance values compared with bulk silicon. Raman spectra measurements showed a broadened peak and shifted below 520 cm-1 for PS layers. In freshly prepared PS layer, the FTIR studies demonstrated the presence of silicon-hydrogen bonds, related to groups formed at the extended PS surface. As the PS layers were stored, various silicon-oxygen vibrational modes became apparent. X-ray diffraction showed when crystal size was reduced toward nanometric scale, then a broadening of diffraction peaks (111) were observed and the width of the peak was directly correlated to the size of the nanocrystalline domains. AFM images showed the PS layer had sponge like structure, and average diameter of pore and thickness of PS layer increased with increasing the current density and etching time. The electrical properties of prepared PS; namely current densityvoltage characteristics in dark, showed that the pass current through the PS layer decreased by increasing the current density and etching time, due to increase the resistivity of PS layer. The PS layer showed a rectifying behaviour with different rectification ratio. C-V measurements demonstrated that the charge carries decrease and width of depletion layer increase by increasing the current density and etching time. The photosensitivity measurements of prepared PS layer showed the peak value in visible region at (400-600nm) increased with increasing the current density and etching time.

Preparation and characterization of silver nanoparticles by chemical methods

By: Salah Mahdi Abd Ulaziz   Supervised By: Assistant Prof. Dr. Mukhlis M. Ismail    year: 2012

Abstract

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This thesis presents new, easy, and quick methods to prepare silver nano-particles at high concentrations without aggregate, non-toxic and free of pollution. The size and properties of these particles are controlled. The AgNPs are prepared the approach chemical reductive silver salt solution (AgNO3) with seven different methods. The main difference between the methods adopting different reducing agents and methods that used same reducing agents but of different quantities is explained. The AgNPs are found to be pure and stable for long time. Structures confirmed from X-ray diffraction (XRD) and the crystillate size was determined using Scherrer's equation to be about 32 nm (for AgNPs were prepared by 1mM of AgNO3 reduce with 2 mM NaBH4). Effect of chemical solutions are studied utilizing absorption spectra measures. This is used to get knowledge of the better concentration for the preparation of NPs, which improves the efficiency of the generation of NPs in the manner of the chemical method. Solutions of NaBH4 at 2 mM, and (CTAB) at 0.8 mM, and oxalic acid at 14 mM, are found to enhance the efficiency for all the generation and the disperse, however, reduceing the aggregation of the AgNPs. Absorption spectra for AgNPs showed a sharp and single absorption peaks. In this search, the peak is extend between range 385-600 nm which indicates the generation of NPs of pure silver. Better concentration for the preparation of silver particles in different solutions such as for NaCl was 5 mM, and PVP at 6 mM, where this concentration enhances the efficiency for all generations, size, dispersion, and prevents aggregation of the NPs prepared. Nanocompsite matter was prepared from AgNPs, and a polymer PVA. Decrease band gab energy for polymer PVA is tuned by adding different concentrations of AgNPs (from 5.82 eV to 2.65 eV).

Study of Physical Properties of CdZnS Ternary Thin Films Prepared by Chemical Bath Deposition

By: Fadheela Hussen Oleiwe   Supervised By: Dr. Selma Mohammed H. Al -Jawad   year: 2012

Abstract

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In this work, a series of Cd1-xZnxS 0.05 ≤ x ≤ 0.7 ternary thin films were prepared on glass substrates using chemical bath deposition (CBD ) method. An attempt was made to modify the band gap of CdS (2.4 eV) by preparing a mixed lattice with a high band gap material, ZnS (3.7 eV), giving a new set of materials. Cadmium sulphate, Zinc sulphate, and thiourea are used as the basic source materials in the deposition bath. Many growth parameters have been considered in this study to specify the optimum condition, namely (temperature of solution, pH, and deposition time) for properties Cd0.5Zn0.5S thin film. Structural, optical and electrical properties of Cd1-xZnxS thin films are investigated and analyzed extensively with respect to growth conditions. The Cd1-xZnxS films are annealed in air at temperatures (300) ºC at constant time of ( 60 min). Structure and surface morphology of Cd1-xZnxS thin films were characterized by X-ray diffraction (XRD), Atomic Force microscope (AFM), Optical Microscopic, and Scanning Electron Microscopy (SEM) Measurements. The XRD indicates that all the grown films show only one diffraction peak located at (2θ= 26.7°) with hexagonal structure in predominant (002). The average grain size changes from (9.3nm to 4.48nm) with the increase in Zn- content (x = 0 to 0.65). It was found that as the Zn- content increases, the peak intensity decreases and for (x ≥ 0.7) the films have amorphous character. The values of lattice constant ‘a’ and ‘ c’ have been observed to vary with composition from (5.75 nm to 4.68 nm) and (6.66 nm to 6.62 nm), respectively, with the increase in Zn- content ( x = 0 - 0.65) . The AFM studies showed that the smooth surface texture was observed in the deposited Cd1-xZnxS films with (x= 0.3) , the surface roughness of the Cd1-xZnxS thin films is about ( 2.66nm to 9.47nm) and the root mean square (RMS) is about ( 3.41nm to 11.9nm) with increase in Zn- content (x = 0.3 to 0.6) .The optical microscopic measurement observes that films surface become increasingly coarse at increasing the Zn- concentration. The SEM exhibits that grains in the film are distributed to cover the surface of the substrate completely, the grains become small in diameters with increasing Zn-contents. The optical properties of Cd1-xZnxS thin films were studied by the transmittance, absorption coefficient and energy gap for deposition conditions (80ºC temperature pH= 10 and time 3h). The transmittance is measured in the range from ( 300 nm to 900 nm) for all the films, in the visible wavelength region, the average transmittance greater than (80 %) at Zn-content (x = 0 to 0.7). The Cd1-xZnxS thin films have high optical absorption coefficients where the value reaches at (1.2×105 cm-1). The energy band gap ( Eg) values of Cd1-xZnxS thin films are ( 2.4 eV to 3.4 eV) corresponding to the Zn-content ( x = 0 to 0.7) respectively. In other word, the optical band gap of Cd1-xZnxS thin films become wider as Zn-content increases. All the Cd1-xZnxS films show that the resistivity varied in the range ( 0.45× 103 Ω.cm to 5.9× 103 Ω.cm) corresponding to the Zn-content (x = 0 to 0.7), respectively. Also the activation energies Ea1 (0.124 eV to 0.833 eV) and Ea2 (0.063 eV to 0.277 eV) varied with the increasing Zn-content (x) in the films (x = 0 to 0.7). Hall measurements indicate that the Cd1-xZnxS thin films have same conduction type (n-type) conductivity. The carrier concentration and mobility values for Cd1-xZnxS thin films vary with zinc content , furthermore their values are (5.201× 10¹² cm-3- 1.263× 1012cm-3) and (140.5 5 cm2V-1S-1 - 22.435 cm2V-1S-1 ) respectively.

Effect of Changing Different Preparation Conditions on Physical Properties of Zinc Oxide Nanoparticles Prepared by LP-PLA technique

By: Halah Hassan Rashed   Supervised By: Assist. prof. Dr. Evan T. Salem   year: 2012

Abstract

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In this work ZnO Nanoparticles were fabricated using Liquid Phase Pulse Laser Ablation technique and gives very simple, cheap and a single step method for the preparation of zinc oxide Nanoparticles with no need for any complex or expensive further steps. Also, It shows a long period of stability, less aggregation, non toxic and contamination colloidal Nanoparticles, In addition this work provides a controlled method to prepare Nanoparticles with a specific properties depended on the preparation conditions and laser parameters. In the present work, at which ablation of pure Zn metal target in DIW was accomplished using 9 nsec Q-switched Nd:YAG laser at (1.06 µm) laser wavelength , at different laser fluence and number of laser pulses, and the effect of these parameters on optical, photoluminescence, amount of ablated material, structural and surface morphology have been studied. The atomic absorption result shows that the amount of the ablated material is directly proportional to the laser fluence and number of laser pulses. The UV-Visible show a red shift in the absorption spectra related to the shift in the energy gap due to the size increase in the particle size with to higher laser fluence. A blue shift was however recognized with a larger number of laser pulses. The photoluminescence result gives a blue shift with the decrease in laser fluence and number of laser pulses. The X-Ray diffraction pattern revealed the presence of (100) plane related to ZnO wurtize structure. The Fourier transform infrared spectroscopy result shows that the intensity of the Zn-O bond vibrational mode is proportional directly to the laser fluence and the number of laser pulses. Grain size of the obtained NPs are found to increase with laser fluence and decreased with the number of laser pulses as shown by the AFM result.

Sliding Wear Behavior of Oxygen-Free High Conductivity Copper C10300, AA4145 Aluminum Alloy and Brass Alpha under Lubricated Condition

By: Haitham Talib Hussein   Supervised By: Dr. AbdulHadi Kadhim Alogailai   year: 2012

Abstract

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Improvement the Efficiency of Silicon Solar Cell

By: Luban Rasheed Majeed   Supervised By: Dr. Sariya D.AL. ALgawi   year: 2009

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In this work, we prepared a thin film of In2O3 by rapid thermal oxidation at different thickness (106-200-350-500nm) within a range of oxidation temperature (350-400-450C°). Two types of substrate have been used in this work; the structural, optical and electrical properties have been studies for those films which prepared on glass substrates. Also the films are deposited onto the second type p-n junction's silicon solar cells, to study the performance of this film as antireflection coating. The structural properties for the prepared films In2O3 were studied through tests optical microscope and X-Ray diffraction, it is appeared that the film, is polycrystalline. The optical properties show an increasing in transmission characteristics at the visible (400-700nm).the direct energy band gap have been increased with increasing the film thickness from (3.41-3.63eV),however for indirect it is increased with thickness from (2.25-2.65eV). The calculations also included some optical constants such that transmittance, absorption coefficient and refractive index. The electrical properties of In2O3 film, shows that the activation energy of the film to be about (0.5-0.38eV) in the range of temperature (30-150 C°) and results of Hall effect shows that the type of the film is (n-type) ,and that the Hall constant decreases as thickness increases. The measurement of the short circuit current-open circuit voltage show improved with conversion efficiency of the p-n junction solar cell after coating by In2O3 film an increases film thickness and oxidation temperature ( 3.95%) before coating it became (10.95%) after coating by In2O3 film 500nm thickness at 450C° oxidation temperature And through the study of the detectives properties ,the maximum spectral response at the wave length 800nm was (0.126A/W) before the coating improved after coating it became (0.45A/W) ,at the same wavelength, as for the Quantum efficiency ,it was( 1.95%) before the coating became ( 7%) at the same wave length by In2O3 film 500nm thickness at 450C° oxidation temperature . And at studying of the short circuit current-open circuit voltage of the solar cell before and after texturing and coating by In2O3 film show improved with conversion efficiency (0.29%) before texturing , while after texturing and coating by In2O3 film it became (3%) also show the measurement improved with spectral response and Quantum efficiency , was the maximum spectral (0.036A/W) before texturing at the wave length 800nm improved after texturing and coating by In2O3 film it became (0.24A/W) ,at the same wave length, as for the Quantum efficiency ,it was(0.55%) before the texturing it became ( 3.83%) after the texturing and coating this to make the film as anti reflecting coating .

Increasing the conductivity of cadmium telluride films

By: Waseem Najeeb Ibrahim   Supervised By: Asst. Prof. D. Muslm F. Gwaad Al-Zubadi    year:2009

Abstract

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In this work ,the study of structural,optical and electrical properties of (CdTe) thin films which was prepared by thermal vacuum evaporation on glass substrate at room temperature, the annealing effect and CdCl2 heat treatment effect at (300˚C) temperature for (15min) time on the film properties was studied, in addition to study the effect of CdCl2 heat treatment for various molariries (0.1,0.2,0.3)M ,dipping time (5,10,15)min and anealing time (5,15,30)min on the properties of films . The structural studies have been performed by X-Ray diffraction technique which showed that the deposition film is polycrystalline in nature , and increasing in the grain size after annealing and CdCl2 treatment and contrast in appearence and disappearence of planes in crystal structure, optical microscope was employed to study the surface morphologies . From optical measurement , the deposited film have direct energy band gap (Eg) and it was found to be (1.56,1.54,1.48) eV for deposited films at room temperature and annealed without and with CdCl2 treatment at (300˚C) for (15min) respectively . The electrical measurements explained that D.C. conductivity increased after the film annealing and CdCl2 treatment and all films have two values of activation energy (Ea1) and (Ea2) and found that it decreased after annealing and CdCl2 treatment , from the study of Hall effect , all samples showed that (p-type) with carriers concentration (p) and mobility () increases after annealing and CdCl2 treatment , from the results of current – voltage characteristics for dark and illumination of CdTe thin films explain that the dark and photo current increased after annealing and CdCl2 heat treatment .

Oxidation of cadmium thin films and studying some physical properties

By: Atheer Ibraheem Abd Ali AL-Khfagy   Supervised By: Dr. Ali M. Mousa Al-Zuhery   year: 2007

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Transparent Conducting Oxide (TCO) is a Special Type of Material, Since They have Metallic Electrical Conductivity and at same Time They are Highly Transparent and for a Wide Range of Wave length. The Band Gab They Have Makes Them suitably for a wide Rang of Application's Cadmium Oxide (CdO) is one of These Oxide, Which have been Used Studied Vastly and a different method have been used for the Deposition. in this Work we Oxidize Cadmium Thin Film's Which already Deposited by D.C Sputtering. During The Work, we Studied the Heat of annealing Temperature and annealing Time from the Work all Treated Film's was Polycrystalline with different Diagram according to annealing parameter. The plane (111) is the predominate and with the (200)&(220) the Cadmium plain appeared only for the Film annealing with (2)mint and (200º C) , also it is appeared with annealing Temperature (100º C) and (30)mint from the Optical measurement we a sure that the Band Gab is direct With value Ranged between (2.4-2.7)eV and the Transition are allowed direct certain Sample. Which Show littlie bit and this may be due to defect al Film's have high absorption Coefficient Ranged (104-105)cm-1 also Electrical measurement shoed They Activation Energy Ranged (0.013-0.12)eV which means that Fermi level is near by films have highly Electrical Conductivity (102 – 103) Ω-1.cm-1 which is Probability due to the Presence of Cadmium atoms.

تأثير اضافة الزركونيا (ZrO2) في الخواص الميكانيكية والحرارية للبوكسايت العراقي

By: انتصار محمد خضير البدراني    Supervised By: د. شهاب أحمد زيدان الجبوري   year: 2008

Abstract

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Use Iraqi Bauxite (64.2%) Alumina was calculated at (1400 ) and Grain gradient limited after add kaolin and Sodium Silicate to increase compaction bauxite grain and then addition different weight percentage from zirconia to mixture (20%, 15%, 10%, 5%). The samples were formed by using bi- axial pressing. These samples were fired in two temperatures (1200 , 1400 ) . Studies the physical properties (Shrinkage, density and porosity), thermal properties (thermal conductivity, thermal expansion , specific heat capacity, and thermal shock), mechanical properties (compression strength , and Diametrical strength). Found from measuring get simple change in (Shrinkage dimension and thermal expansion) with add ZrO2 , increasing of zirconia percentage leads to decreasing of (mass shrinkage , porosity, thermal conductivity, specific heat capacity). And increasing of (density and compression strength). Add zirconia effected on properties from two side; first from side properties and another from side made zirconium silicate phase.

a study of behaviourism of thermal isolation and fire-proofing for cement-perlite mortar

By: hassan hady hussein   Supervised By: Dr.balkees.m.deya    year: 2008

Abstract

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The research involves the use of lightweight aggregate (perlite) with Portland cement to make perlite mortar using to Improve the thermal isolation and fire proof for masonry units. The cement:perlite ratio was [ 1:7, 1:5.6, 1:4.7, 1.4, 1:3.5] by volume. The research involves a study of mechanical, thermal and physical properties for all specimens that had been make in normal situation. One of the mechanical properties, which were study, is the percentage of flow to know the amount of flow ability and maintained between (90 – 100 %). Where the mechanical and physical tests are the 28 days air-dry density and compressive strength respectively. In addition, for the thermal properties that have been study are the thermal conductivity and time endurance on the flame for dry specimens in 60 day old. The other physical properties are the study of the effect of increasing the thickness or the amount of cement of specimens at the time endurance on fire. Generally the result shows that the increasing of cement quantity are improves the workability of the mortar and decreasing the water-cement ratio as comported to a mortar poor in cement moreover that rising up the value of compressive strength and air-dry density. In another hand the experimental work proof that the increasing of cement ratio on the mix (mortar) is effect negatively on the thermal properties of the dry mortar by increasing the value of the thermal conductivity and decreasing the time endurance on the fire for the tested specimens moreover that increase the cracks and make it show early. Moreover above, when we fix the cement:perlite ratio in the mortar and increasing the thickness of the specimens to study the physical properties We found that the increasing effect positively on the time endurance on the fire. In addition, from all physical and thermal experimental that has been making we found that the perlite is working like a scattering material for the heat, because of its porosity, that can contain the air inside it and this porosity make the heat transfer be slower as comported with another solid material, and for all of this, the perlite is one of most successful isolations for a heat less than 800 degrees.

Preparation of BST Ferroclectric Materail Using Wet - Chemical Method and Studying Their Structural and Physical Properties

By: Rawa ahmed helal al omairy   Supervised By: DR. SABAH M.A.RIDH   year: 2008

Abstract

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BaxSr1-xTiO3 (BST) ferroelectric nano powders were processed with three concentrations (x = 0.5, 0.7 and 0.9) by reacting TiO2 powder in aqueous solution of BaCl2 and SrCl2 using a technique known as oxalic acid route. A sintering process has been done at temperature (800oC, 1000 oC and 1100 oC) and a soaked time (1.5h, 2.5h, 4h), in this step, the solid phase reaction takes place between the constituents giving the ferroelectric phase. XRD analysis has been carried out in order to examine the appearance and the stability of the BST ferroelectric phase. Also the grain size obtained from this test which reached to (15.4, 34.65, 42.13 nm) for the three concentrations (x = 0.5, 0.7 and 0.9) respectively. The ferroelectric phase was subjected to several tests to obtain some of the BST ferroelectric properties. The microstructure test which gives a clearly observation about the distortion and the grain growth for the same subjected samples to the XRD analysis. Then, an electrical test involves a permittivity with temperature, the permittivity reached to (more than 530,700 and 500) at Curie temperature, while the loss factor reached (0.175, 0.19, and 0.2). The quality factor and the resistivity with temperature were examined too, all these tests have been done for the three concentrations of BST system. Moreover permittivity, loss factor and the quality factor with frequency in ranges (103 - 105 Hz) were studied and we found that these tests (permittivity, loss factor and quality) exhibit good stability in this range of frequency. The last test was the breakdown strength test. The BST apparent densities were (5.5, 5.5, 5.45) gm/cm3 for (x = 0.5, 0.7 and 0.9) respectively by using Archimedes law, while the bulk density and apparent porosity were calculated arithmetical. The shrinkage was too small for all of the three systems. In this investigation we found that the oxalic acid method is a good method to prepare a ferroelectric phase with high density and small porosity. The nano BST grains and the high density have large dependence in the electrical properties, which is clearly observed in the broaden of the permittivity and loss factor peaks, in other words the broaden indicated that the transition never depend on Curie temperature and this is an important property in microwave applications. The stability of the permittivity, loss factor and quality with frequency range (103 -105 Hz) imply to the good capability of using nano BST ferroelectric in tunable devices.

Preperation of polymer semiconductor and study their electrical properties

By: Dr. Sewench N. Rafeeq   Supervised By: Dr. Moayyd N. Fat – Hulla   year: 2008

Abstract

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تم تحضير متراكب بوليمري من بولي فانيل الكحول / بولي أنلين بعملية الاكسدة الكميائية للأنلين مستعملاً نوعين من العوامل المؤكسدة (6H2O. Fecl3) و (2H2O . Cucl2) وذلك بثلاث طرق تحضيرية:

  1. تحضير نماذج من بولي فاينل الكحول بسمك (1 mm) ثم غمرها في مونو مير الانلين لمدة (3) أيام وبعد تجفيفها تم ادخالها في محاليل العوامل المؤكسدةالمحضرة بتراكيز مختلفة، وبأستخدام نوعين من المذيبات (الايثانول والاسيتونيترال)مستخدما فترات زمنية مختلفة لعملية البلمرة.
  2. تحضير نماذج منبولي فاينل الكحول المحمل بالعامل المؤكسد (mm1) بتراكيز مختلفة وتم تعريضها الى بخار الانلين لمدة (12) يوم.
  3. تحضير نماذج من بولي فاينل الكحول المحمل بالعامل المؤكسد(mm1) بتراكيز مختلفة وتم تعريضها الى بخار كل من الانلين وحامض الهيدروكلوريك بتركيز (1N) في انٍ واحد ولفترة زمنية محددة (7) أيام.

تم دراسة الخواص الكهربائية لنماذج المحضرة والتي تضمنت سلوك التيار الفولتية، التوصيلية الكهربائية وتأثير درجة الحرارة عليها. أظهرت النتائج ان النماذج المحضرة تمتلك خاصية توصيلية كهربائية والتي تعتمد على كل من تراكيز المحاليل المؤكسدة وزمن البلمرة وطريقة التحضير. تم التعرف على نوعية وتركيز وحركية حاملات الشحنة بتطبيق تأثير هول بينما طاقة التنشيط ونوع حاملات الشحنة بتطبيق تأثير سيبك والتي اظهرت ان حاملات الشحنة هي من نوع (P) واظهرت صفة أشباه الموصلات. تم التصوير المجهري وفحص X-ray لنماذج محددة.

Deposition and Study of Physical Properties of CuxS Thin Films Prepared by Chemical Bath Deposition

By: Abbas Fadhil Sabbar Al- Shareefi   Supervised By: Dr. Ali M. Mousa    year: 2008

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Structural, optical and electrical properties of copper sulfide films were investigated and analyzed extensively with respect to growth conditions. Annealing in vacuum at pressure 2x10-2 torr, different temperature (100,150,200,250 and 300) °C at constant time of 30 min, were adopted. The annealing process in different times (15,60,90,120, and 240) min at constant temperature of 200 ºC were adopted as well. The effects of doping on the properties of the films were studied. Two types of doping salts were used (AlCl3 & FeCl3) with four different weights (1, 1.5, 2 and 2.5) mg. From XRD, it has been fond that all films at different deposition parameters are amorphous, but annealed films showed some degree of crystallinity. Doping has no effect on the XRD. Optical measurements contained study of transmission and absorption by using spectrophotometer were carried out. Transmittance decreased with increasing the dipping number and doping weights, while the transmittance increased with increasing the time and temperature of annealing .The direct optical energy band gap range was between (2.17-2.56) eV. The electrical conductivity increased with increasing of dipping number, also with increasing the doping weight of Al .While the electrical conductivity deceased with the increasing of doping weight of Fe and with annealing time and temperature. The electrical conductivity was found to be (0.044- 45.453) (Ωcm)-1, whereas the activation energy was (0.115 -0.948) eV.

Study the Electrical Properties of Piezoelectric Material (PZT) Prepared by Organic acid Precursor Method

By: Abdul karim Ziedan Khalf Al- Jebory    Supervised By: Asst. Prof. Dr. Sabah M. Ali Ridha   year: 2008

Abstract

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the present work the compound of piezoelectric nanopowders with a general system PbZrxTi1-xO3 (PZT) at (x =0.3, 0.5 and 0.7) was prepared using organic acid precursor method. The prepared sample was subjected to some tests in order to obtain several of PZT piezoelectric properties. X-Ray diffraction (XRD) analysis was used to examine the growth and stability of PZT piezoelectric phases. Then grain sizes were measured (39, 36 and 30 nm) for (x=0.3, 0.5 and 0.7) receptively. The microstructure of the prepared sample was studied by using optical microscope to observation the distribution and the grain growth. Physical properties such as bulk density, apparent density, apparent porosity and the shrinkage were measured, where the value of bulk density reached (5.78, 6.11, 5.9 gm/cm3) at 1100oC for 2h. On the other hand, the shrinkage value was (0.064, 0.034, and 0.042) at 700Co when compared with the values (0.0055, 0.011 and 0.0092) at 1100Co at different concentrations (x= 0.3, 0.5 and 0.7) respectively. Electrical properties such as dielectric constant (εr) and dielectric loss (tanδ) were measured as a function of temperature. The value of dielectric constant were reached to (1000, 1200 and 1050) at curie temperature, while the dielectric loss reached (1.1, 1.05 and 1.15) at different concentrations (x= 0.3, 0.5 and 0.7) respectively. In addition electrical resistivity (Ro) and quality factor (Q) were measured as a function of temperature. Also the dielectric strength was measured. Also (dielectric constant, dielectric loss and quality factor) were measured as a function of frequency at range (103-105 Hz), were (εr=270, 365 and 235), (tanδ=0.375, 0.275 and 0.42), (Q=2.7, 3.7 and 2.5) at different concentrations (x= 0.3, 0.5 and 0.7) respectively.

تصميم وتنفيذ منظومة اتصالات ليزر فيديوية باتجاه واحد في الفضاء الحر

By: لبيب عمر عبد الغني النعيمي   Supervised By: د. حيدر عبد الرضا صالح البكري   year: 2008

Abstract

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In this project an optical communication system was designed and implemented to transmit one-video channel simplex technique with line of sight . The constructed simplex optical communication system consists of a transmitter ( uses a laser beam of a wavelength λ = 650 nm as a carrier wave in free space ), and a receiver ( uses PIN diode as a detector ) each in one side. Intensity modulation (IM) technique has been used to transmit video signal of a frequency range (0~5) MHz bandwidth The video signal fed by monitoring camera type (X3 ) 231 and the voice signal fed by Mic, each signal will be amplified and converted to a modulated intensity of laser beam, sent to the associated receiver . Each receiver converts the laser signal to a weak electrical signal ; the signal will be amplified and converted back to an analoque signal to produce the original transmitted signal, and sent to TV set to be monitored in black and white color video with sound . The transmission range for the present system was five meters , that can be developed to suit for longer range .

Preparation of Lead Iodide Layer and Studying the Influence of both Deposition Conditions and Doping on its Physical Properties

By: Natheer Jamal Omran Al-Rubaie   Supervised By: Prof. Dr. Ali M. Mousa    year: 2008

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In this work study, deposition method adopted using solution to deposit lead iodide layers, the method is easy, low cost, provides the possibility of large area deposition at required thickness and dose not need sophisticated techniques. This research studies the influence of deposition under different conditions and doping in the properties of lead iodide layers. Four different deposition conditions are used (deposited samples in dark, deposited samples in dark under the influence of a magnetic field, deposited samples in light, deposited samples in light under the influence of a magnetic field). Also two types of salts dopants were used with four different weights (0.002, 0.0025, 0.003, 0.0035 g) namely: (AlCl3 and CoCl2). Current study focused on structural, optical and electrical properties of layer prepared under different conditions and doping. The experimental results of XRD showed polycrystalline hexagonal structure with four main peaks which correspond to: [(001) (002) (003) (004)]. It is found that both deposition conditions and doping don’t affect on lead iodide structural. The optical measurements data were analyzed and interpreted in term of direct electronic transitions. Transmission spectrum of undoped and doped lead iodide layers exhibit a sharp increment start around (~520 nm) and it becomes sharper with doping. It was observed that lead iodide has wide direct band gap (2.3 eV), the energy gap is affected by depositions conditions and doping; it decreases as samples deposited in dark and with increased doping weight. The electrical measurements showed that the electrical conductivity of PbI2 varies according to deposition conditions and doping. Pure samples showed highest value for sample which's deposited in dark with applied magnetic field (5.05x10-9Ω-1cm-1) and it increased when the film is illuminated by light to (5.15x10-8 Ω-1cm-1). The doped samples showed increasing in the value of dark current with increasing doping weight. The best ratio of photoconductivity to dark conductivity ( ) obtained from doping sample by (Co) doping in weight (0.002g). Also the activation energies determined for different samples and their values changed by the range of (0.38 - 0.162 eV).

Optical and Electrical Properties of CdO Thin Films Prepared by Chemical Bath Deposition Technique

By: Hadia Kadhim J.Alogili   Supervised By: Dr. Selma Mohammed H. Al -Jawad   year: 2008

Abstract

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In this work CdO films were prepared by using chemical bath deposition technique, which is a simple, inexpensive and suitable technique for large deposition area. The cadmium nitrate salt was used as a source of cadmium ions, many growth parameters have been considered in this work to specify the optimum conditions, namely (cadmium ion concentration, deposition time, temperature of solution and pH value).The structure, optical and electrical properties of CdO films are investigated and analyzed extensively with respect to growth conditions. Annealing in air at different temperatures (548, 573, 598, and 623k) at constant time of (15min.), X-Ray diffraction technique has confirmed the formation of cadmium oxide (CdO), and proved that the optimum deposition conditions which produce pure phase of CdO are through molarity of nitrate 0.2M, 80C°, pH=9 and at deposition time of 30min. The average grain size increases with annealing process due to relaxation in the tensile strain for deposition films. High quality films are achieved by adding KCN solution, leading to increasing in average grain size, transmission, and electrical conductivity from 16nm, 75%, and 88 (Ω.cm)-1 to 36nm, 85%, and 365(Ω.cm)-1 respectively after KCN solution added. The values of thermal activation energies in low and high temperature regions could be altered with deposition conditions, where changed from 0.1532eV and 0.2825eV to 0.2910eV and 0.3650eV respectively after KCN added to the preparation solution. The CdO film has two values of activation energies as a result of polycrystalline structure. The CdO film which was deposited by bath contain to the KCN solution, the concentration and mobility of carriers reach to values of 4.5*1019 cm-3 and 50.69 cm2/V.sec respectively.

Study the effect of magnetic field on tap water and (CaCO3 and CaC2O4) solutions

By: Ahmed Salih Hammad   Supervised By: Dr. Ali M. Mousa    year: 2007

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In this work magnetic water was prepared and its properties were studied. Also CaCO3 and CaC2O4 solutions characteristics were studied, which represent the basic components to form scales in the equipments and systems that are in touch with water, calcium oxalate also forms kidney stone. The magnetic field that was used was supplied by electrical magnets, where the magnetic field values were between (0.06-1T), at exposure time of magnetic field (5-35 min). In the first stage of research, tap water was exposed to a magnetic field between (0.06-0.4T) with exposure time ranging between (5-35min). After studying the characteristics of exposed tap water, it was found that the pH value was increased from (7.2 to 7.6) and the conductivity increased from 700(µs/cm) to 725(µs/cm), TDS values also increased from 300 to 340 (ppm), while surface tension was decreased from 0.073 to 0.058 N/m. The second stage of research covers some characteristics of calcium carbonate solution, also morphology and nature of its scales using optical microscope. It was found that after exposing tap water to the magnetic field, pH value were increased from 7.7 to 7.86 and conductivity increased from 140 to 170 (µs/cm), while TDS values were increased from 50 to 80 (ppm). Morphology of calcium carbonate was observed after, exposing it to magnetic field. It was found that the scale was light little adhesion to surface. The third stage of this research deals with calcium oxalate solution, after exposing it to the magnetic field varying from (0.3 to 1)T and exposing time (5-30 min). It was found that the conductivity increased from 50 to 100(µs/cm), TDS values were increased from 50 to 85(ppm).The morphology of CaC2O4 precipitates after magnetic treatment was smooth with little adhesion to surface. Finally it was concluded that the magnetic treatment reduces the scales in the instruments and also has good medical advantages.

Study Of Mechanical and Physical Properties of Novolak Resins Supported With The Iraqi Oil Coal Particles

By: Inteesar Mohammed Shatti   Supervised By: Dr. Salam Hussein Ali   year: 2007

Abstract

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This study was performed by using Phenol-Formaldehyde Resin Type (Novolac) as basic material for the composite material and added to (14%) of the Hardened hexamine tetra mine (HMTA) while the granules of Iraqi oil coal as a supporting material. Samples were prepared in two different percentages of the Reinforcement material (Iraqi oil Coal) in (5%) and in (10%) . After that a study was performed for some of the physical characteristics of the samples and a comparison was made between the results obtained from them. The mechanical characteristics which were studied were represented by the bending test and the impact test. Also the dispersion factor was calculated after submerging the samples simultaneously for a defined period of time in each of distilled water and kerosene and generally the result showed regarding the mechanical the mechanical characteristics. The increase of these characteristics for the mixing percentage determined by (10%) and these two percentages were taken as basis not to concentrate on them in the previous researches and at these two percentages and as follows: In the bending test the module of Elasticity (E) were greater in the percentage of coal amounting (5%) and around (1.024 kn/m2) compared with (0.57 – 0.326 kn/m2) At the mixing percentage amounting (10%). And for the impact test also the impact resistance ranged between (2.24 kj/m2) For the mixing percentage amounting (5%) from the mixing percentage amounting (10%) which ranges between (1.52 kj/m2 – 1.44 kj/m2). In the permeability and dispersion test the samples of mixing percentage amounting (10%) for the oil coal showed resistance to dispersion weaker than the samples of mixing percentage amounting (5%) in kerosene and water respectively.

Parameters Estimation of a Sealed TEA CO2 Laser Catalysts

By: Duha Saadi Ahmed Al-Rifaii   Supervised By: Dr. Adawiya J.Haider   year: 2007

Abstract

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The oxidation of carbon monoxide CO over supported noble metal catalyst is an important part of the catalytic control in sealed-off TEA CO2 laser system. Despite the large number of researches dealing with the subject, kinetics of reaction is still unsettled. However, this project falls into three parts focused on oxidation CO to CO2 over supported noble metal catalysts: The first part is to determine the activity of supported noble metal catalysts (i.e. Pt/Al2O3, Pd/Al2O3) in removal CO as CO2 gas phase, and study the effect of reaction rate parameter k (sec ) on conversion processes of CO to CO2 at =2500 (sec) by using model of first order reaction at isothermal conditions. The second part is to calculate CO2 production rates for the steady state oxidation of CO over supported noble metal catalyst such as (Pt/Al2O3) in mathematical models at temperature T=473(K) and pressure p=1(atm) that produce for Herz & Marin model-I and for Herz & Marin model-II. Then they are compared with Langmuir-Hinshelwood-Hougen-Watson rate, which is about . Also, these results improve first order reaction in CO2 at low concentration of CO. The effect of temperatures range (476K to 570K) on CO2 rates ( ) was also investigated and shows the same behavior of first order reaction in CO2. Finally, according to the results of CO2 production rates ( ) of Herz & Marin model-I and II, the volume of catalyst ( ) was calculated by using the numerical evaluation of integral space time ( ) at constant volume (i.e. dv/dt=0) and volumetric flow rate Q=10(cm . sec ) which give a technological path to design catalyst reactor in sealed-off CO2 laser system for the experimental part.

using of laser therapy in bacterial wounds

By: Lamya Fadhel Al – Barram    Supervised By: Prof.Dr. Jassim .Al – Hilo and Dr. Akram . Al – Mashhdani    year: 2007

Abstract

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The effect of laser to killing & inactivate wounds bacteria has been studied, in order to using it as an active method for sterilization & treatment. To achieve that, two types of pathogen wounds bacteria were used, which isolated from the wounds patients at Al – kindee hospital , they were : Staphylococcus aureus & Pseudomonas aeruginosa . Photosensitization technique was applied as a method for bacterial killing using Toludine blue – O (photosensitizers) conjugated with three types of lasers that emitted in the visible region of the electromagnetic spectrum:  Argon laser with power of 150 mW , and wavelength of 514 nm , was used at the first time for bacterial killing field by photosensitization technique.  Nd:YVO4 laser with power of 10 mW , and wavelength of 532 nm, was used at the first time for bacterial killing field by photosensitization technique.  He – Ne laser , with power of 5 mW , and wavelength of 632.8 nm. Bacteria were irradiated after spread it on the nutrient medium (blood agar) by using four concentrations of the photosensitizer Toludine blue – O (0.01 , 0.05 , 0.1 ,0.2)% (w/v) at 1 cm & 50 cm (distance from the irradiation source) , for S . aureus. For P. aeruginosa and mixture of two bacteria , the concentrations using were reduced to 0.01 , 0.05 , 0.1 % (w/v) , and the distance between the irradiation source and the sample was choosed as 50 cm only . All of samples were irradiated without using the Toludine blue – O (0.0 % (w/v)) . The irradiation results revealed appearance of a clear bacterial killing regions equivalent to laser spot size diameter (and more of that) when the two types of bacteria and their mixture were irradiated by Argon laser at all dyes concentrations & all irradiation periods which range 1 , 2 , 3 , 4 , 8 minutes by comparison with the Nd:YVO4 and He – Ne lasers . Bacterial killing regions were obtained when S . aureus bacteria were irradiated by Argon laser for 1 minute at 0.01 % (w/v), whereas bacterial killing regions were noticed during irradiating for 8 minutes by He – Ne laser & for 12 minutes by Nd:YVO4 laser using 0.05 % (w/v) at 1 cm & 50 cm (from the irradiation source and the sample) . In addition , Bacterial killing regions were equivalent to laser spot size diameter (and more of that) were obtained when the tow types of bacteria and their mixture irradiated by Argon laser without using the Toludine blue – O (laser alone) , whereas no any Bacterial killing regions appeared when they irradiated by Nd:YVO4 & He – Ne lasers alone (without using photosensitizer) even the period irradiation reached to 15 minutes. On the other hand , the 0.1 % (w/v)concentration of Toludine blue – O dye was considered as an ideal concentration, when it using as a photosensitizer conjugated with laser light to form the photochemical reaction , because the Bacterial killing regions were noticed for all treatments with three types lasers irradiations and for all irradiation periods . In this study , increasing of P. aeruginosa bacteria sensitivity to killing by photosensitization technique were revealed , by the comparison with the S . aureus bacteria when using the Toludine blue – O dye conjugated with three types of lasers, the best diameter for bacterial killing were obtained about 6 mm when P. aeruginosa bacteria were irradiated by Argon laser for 3 minutes by using 0.1 % (w/v) of the photosensitizer, whereas bacterial killing diameter was about 5 mm when S . aureus bacteria irradiated by Argon laser for 4 minutes by using the same photosensitizer concentration . On the other hand, the results were revealed that there is no a clear differences of Bacterial killing regions formation when S . aureus bacteria were irradiated at 1 cm or 50 cm (the distance between the irradiation source and the sample) .

Study the Optical and Electrical Properties of Silicon Nanostructure

By: Mohammed Abdul Sattar Ibrahem   Supervised By: Dr. Bassam Ghalib Rasheed   year: 2007

Abstract

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Construction of Pulsed Laser Ablation (PLA) system has been carried out. Nd:YAG pulsed laser has been employed to prepare silicon films constituting silicon nanoparticles. Various laser parameters were examined to produce films of different properties such as the laser energy, laser fluence, number of pulses and the targetsubstrate distance. We have studied the optical, structural and some electrical properties of the deposited films. Optical properties were included like the transmission, absorption, electronic and photoluminescence while a study on the structural properties was carried out using x-ray diffraction and the film morphology. Moreover, J-V characteristic in the dark and under light illumination have been conducted to study some of the film electrical properties. Our experimental data have been fitted with the theoretical quantum confinement model to analyze the photoluminescence curves and estimate the nanoparticle sizes and their distribution. From the optical transmission studies, we have found that the band gap of the nanostructured films lies between (1.5 – 2.4) eV due to the existence of various nanoparticle sizes in the deposited film. Furthermore, the photoluminescence (PL) spectra indicate that the estimated band gap lies between (1.6 – 2.4) eV. The corresponding nanoparticle sizes contributing the PL emission is in the range (22 – 38) A°. These results were found to be inconsistent with that obtained by the x-ray analysis. Finally, it was observed that the film morphology is significantly affected by the laser fluence and the target-substrate distance. Therefore, one could prepare various films suitable for different applications.

تأثير نسب الخلطات HIPS / PP على بعض الخواص الميكانيكية والفيزياوية

By: مصطفى عبد الستار أبراهيم   Supervised By: الدكتورة بثينة علاء الدين أبراهيم   year: 2007

Abstract

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The project involved the preparation of two-polymer blends of Poly-Propylene (PP), and high impact polystyrene (HIPS) in different proportions (50-100)% with the aim of arriving at the best physical blending percentage. For this purpose, a single-screw extruder is used in test-sample preparation, followed by hot-press several plates extruded along opposite directions. In order to study the influence of blending on the mechanical properties and some physical properties, several tests are performed included (tensile, compression, bending strength, impact resistance, creep and relaxation time, thermal conductivity, and dielectric constant, diffusion test using alkaline(KOH), acidic(HNO3), and saline(CaCl2) solution, in addition to optical microscopy and thickness measurement of extruded plate-samples ). Longitudinal and transverse tensile tests are performed for the extruded test-samples while for pressed - plate samples only longitudinal tensile test is done. In both cases, results reveal that the best blending percentage is (80/20)%(PP/HIPS), derived from tensile and ultimate stress when compared with those for pure pressed materials. Test results of extruded test samples show elongation percentage improvement with improved mechanical properties . From the calculations of modulus of elasticity for tensile, bending and compression, and from hardness tests, the best blending percentage is (70/30)%(PP/HIPS), also at this blending percentage, the greatest creep rate and relaxation times are realized. Impact resistance results show that for all blending percentages are lower than that for pure (HIPS), with some improvement for the blending percentages (50/50)%, (60/40)%, (90/10)% of (PP/HIPS) as compared to pure polypropylene. Thermal conductivity results are found to vary between those for pure polypropylene and high-impact polystyrene except for the blending percentages (70/30)% and (90/10)% (PP/HIPS) which appear higher. Dielectric tests reveal that the dielectric constant, in general, shows higher value than that for pure polypropylene and high-impact polystyrene . Diffusion coefficient tests results show the highest obtained value is for the (60/40) % and (50/50) % (PP/HIPS) blends, while for the other blend percentages it varies between that for polypropylene and high-impact polystyrene with some apparent improvement due to the effect of chlorides on the blends except of the (50/50)%(PP/HIPS) blend. Thickness measurements reveal that plate thickness increases with increase of (HIPS) percentage, with gradual decrease in brightness of samples, greatest brightness is observed in the (90/10)%(PP/HIPS) blend. Pure polypropylene appears transparent. Optical microscopy shows increase in crystallinity with gradual increase in nucleation reaching nucleation in high-impact polystyrene.

Study Into Some physical properties of NiS Thin Film Prepared By Spraying Pyrolysis

By: Wasna'a Mohammed Abed Al-Rodh   Supervised By: Prof. Dr. Alaa El – Naimi   year: 2007

Abstract

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In this research, Nickel Sulphide thin films have been prepared by Spray Pyrolysis deposited on thin glass substrate at 513±278kº to study their structural, optical & electrical properties, Nickel Sulphide thin films have been prepared by using 0.05M Nickel Chloride aqueous solution & Thioria aqueous 0.05 M. The effect of annealing on thin films at 350Co temperature & time of 60min was also studied. The results of (X – ray) diffraction showed that NiS thin films have amorphous structure, but the annealed films started to have a polycrystalline structure. Optical microscope showed that the annealing of films had reduced the surface deformation. The optical measurements show that the films have relatively high absorption coefficient(1.8×105cm-1) at wavelength from 950nm up to 1200nm & the absorption coefficient reduce with the annealing (1.05×105cm-1). The energy gap was increase when the films annealed from(1.05)eV up to)1.16)eV for the direct–allowed transition and from(0.99)eV to (1.06)eV for the an-allowed transition and(0.96)eV to(1.045)eV for an direct–allowed transition an from(0.9)eV to(1.0(1eV for an-allowed-in direct transition. Through studying the electrical conductivity, it has been found that it decreases with annealing at temperature of 623ko, the activation energy for un-annealed thin film was (0.7eV) but after annealed it was (0.8eV). Seebak effect showed that all films are P–type for the annealed and un-annealed films.

Analytical Study of Opacity and Escape Factore in Laser Produced Plasma

By: Rahman Ismiel Mahdi   Supervised By: Dr. Sabah H. Sabeeh    year: 2006

Abstract

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An analytical study of spectral lines (in soft x-ray region) of laser produced plasma (LPP) is carried out. The work is concentrated on two main points, firstly: studying of the opacity broadening of spectral lines and secondly: studying the escape factor of photons. The opacity broadening and escape factor are studied for Al, C, Mg, Si, Ge and LiF plasmas, the selected wavelengths was (6–35 Å) which have a lot of applications in many fields such as biological applications (x-ray microscopy), integrate circuit industry , x-ray laser , x-ray source etc . The opacity broadening is studied as a function of plasma size and plasma density, the effect of the difference between energy levels of emission spectral lines on opacity of plasma is also studied. The escape factor which represents the probability of photons to escape from plasma is studied as a function of opacity. From our results that have been obtained one can notice that the opacity of plasma increases with increases in size and density of plasma, atomic number of target and also it is increases with decreases the difference of energy between energy levels of spectral lines. We notice also that the escape factor is increases with decreases the opacity, where the escape factor of spectral line of higher series member transitions is very large compare with the escape factor of spectral line of lower series member transitions ,and also we found that the escape factor is decreases with increases the atomic number of the target .

The Effect of Doping & Annealing In Some Physical Properties Of Cu2S Thin Film Prepared By Spraying Pyrolysis

By: Mustafa Amer Hassan    Supervised By: Prof. D. Alaa Al – Naimi   year: 2006

Abstract

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In this research, Copper Sulphide thin films have been prepared by spray pyrolysis to study their structural , optical & electrical properties by using 0.1M Copper nitrate aqueous solution & Thioria aqueous 0.1M & 0.4M . The films were doped with Aluminum by 1%, 2%, 3% ratios. In addition to this the effect of annealing on the undoped thin films at 200Co temperature & different times of 60min. & 120min. were investigated . The results of ( X – ray ) diffraction showed that the doped and undoped have amorphous structure , but the annealed films start to have a polycrystalline structure . The films prepared with a low ratio of Thioria have a high amounts of Chalcocite phase. Optical microscope showed that the annealing & doping of films had reduce the surface deformation. The optical measurements show that the films with low ratio of Thioria have relatively high absorption coefficient & the absorption coefficient increase with the doping ratio & reduce with increase the Thioria concentration & annealing time. The allowed direct energy gap was reduced with doping & increase when the films annealed. Through studying the electrical conductivity, it has been found that it increase with increasing of doping ratio & decreases with annealing at temperature of 200Co . But Thioria concentration is the mean operator acting in the electrical conductivity where conductivity increase with increasing Thioria concentration. Seebak effect showed that all films are P - type.

Study Gamma Ray Buildup Factor For Black Carbon And Graphite

By: Nabeil Janan Bahnam    Supervised By: Dr.Nabeil E. Fawaz   year: 2006

Abstract

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The number buildup factor (B.U.F) for two source and 1.012 mCi (37.444 MBq) and 1.304 mCi (48.248MBq) using scintillation detector (3"×3") NaI(Tℓ) to the Iraqi powders of black carbon (B.C) and graphite after mixing with remnant binder material (epoxy risen) with mixing ratios 40% and 50% ,were studied in this research. Four cylindrical shields were made with diameter of 6.2cm, two from black carbon (B.C) with mixing ratio 40% and 50% and another two from graphite, with thickness between (0.5-7.58)cm for each shields .the linear attenuation coefficients and buildup factor were calculated. Empirical equations (Capo, Berger, Power, Taylor, and Exponential) were used to fit the experimental buildup factor data. The fitting were successful with equations (Capo, Berger, Power) and the Average Percentage Diversion estimated to be (0.16% , 0.21%, 0.22%) respectively, large diversion were noticed when (Taylor, Exponential) equations been used with A.P.D (0.36% , 0.71%) respectively. The result illustrating that the buildup factor with energy 1.25 MeV for black carbon and graphite (40% and 50%) with thickness between (0-0.5398 ) and (0-0.7541) m.f.p respectively, highly depends on the mixing ratios, bulk density and type of material. Reductions in buildup factor values were noticed with increasing the mixing ratios, bulk density. Moreover the buildup factor values for black carbon found to be higher than that for graphite. Result also shows, that the buildup factor with energy 0.662 MeV for both black carbon and graphite with 50% mixing and thickness rang between (0-8421) m.f.p , a little increase for black carbon of thickness . No effect for mixing ratios, bulk density and type of material were noticed at this energy. There is an increased in buildup factor values when the radiation energy increased.

The Ehrhart polynomial of Zonohedron and its applications

By: Manar Musab Ftekhaan    Supervised By: Asst.prof.Dr. Shatha Assaad salman    year: 2013

Abstract

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Some basic mathematical tools such as convex sets, polytopes and combinatorial topology, are used quite heavily in applied fields such as geometric modeling, meshing, computer vision, medical imaging and robotics. It is intended for a broad audience of mathematically inclined. A polytope plays a central role in different areas of mathematics; therefore we shall take a polytope with one kind of them, which is known as a Zonohedron. The matroid and arithmetic matroid with their properties are also given. The concept of the Platonic solids is introduced with their properties. Multiplicity Tutte polynomial and Ehrhart polynomial for a Zonohedron Z(X) in 2-dimension and 3-dimensions are introduced. Theorem for the relation between the numbers of integral points of a Zonohedron and the set of generating vectors is proved. Combinatorial interpretation of the associated multiplicity Tutte polynomial with different examples is presented to demonstrate our results. The expression ‘duality’ means a mapping between points and plans (or vertices and faces) is introduced, together with the computation of the Ehrhart polynomial for the dual of Zonohedron and platonic solid.

AN IMPROVED SECRET SHARING SCHEME BASED ON GRAPH THEORY

By: KADHIM ALI KADHIM Al-RUBAYE   Supervised By: Asst. prof. Dr. Nadia Mohammed Ghanim and Asst. prof. Dr. Nuha Abd-uljabbar Rajab    year: 2013

Abstract

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In this work, a novel construction of a secret sharing scheme is proposed and proved to be new theorems and observations depending on some special graph’s properties such as regularity degree and dominating cardinality. In this work the minimum independent dominating set of vertices as an access structure is used to find the key instead of the theories used in previous methods such as H. Sun method. Some algorithms that helps to implement this novel construction are designed as follows: algorithm to find minimum independent dominating set of vertices (MID). algorithms to construct and reconstruct the proposed secret sharing scheme of ranks 2, 3, m≥4. The information rate (ρ) is used as a measure for the efficiency of secret sharing scheme. Therefore, the main aim of this study is to improve information rate values by applying the proposed method to 21 different graphs which have an order between 4 to 24 and regularity degree between 2 to 8, the resulted information rate for proposed perfect secret sharing scheme has an improvement over other methods such as H. Sun and S. Shieh method and Stinson method and we found that: For rank 2: =2/r , while the higher information rate obtained by H. Sun and S. Shieh method is ρ=2/(r+1). For rank 3: ρ=6/((n-r)(n-r-1)+2), while the higher information rate obtained by H. Sun method is ρ=6/((n-1)^2+2). For rank m≥4: ρ=(m-1)!/(((n-r)(n-r-1)+1) ) , while the higher information rate obtained by H. Sun method is ρ=6/((n-1)^2+2). To apply the proposed method to big graphs with a large number of vertices, the proposed algorithms and H. Sun method have been implemented by using VB. NET 2008. In order to satisfy fair comparison under the same environments, the results values agree with the theoretical results, where the experimental result is deduced to prove the efficiency of this method over other previous method in term of information rate and execution time.

ON SOME RESULTS OF ANALYSIS IN A STANDARD FUZZY METRIC SPACES

By: Zeina Abdul Ameer Hussain   Supervised By: Assistant Professor Dr.Jehad R.Kider   year: 2013

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In this thesis the definition of standard fuzzy metric space is introduced as a modification of the notion of fuzzy metric space due to Kramosil and Michalek then several properties of this space are studied and discussed after some illustrative examples are given. Further the definition of convergence sequence, Cauchy sequence and F-bounded standard fuzzy metric space are modified. Also the definition of continuous and uniform continuous function are modified , we proved that a mapping f:X→Y is continuous on X if and only if f^(-1)(G) is open in X for all open subset G of Y . A necessary and sufficient condition for a standard fuzzy metric space to be complete is given then completions of standard fuzzy metric space are discussed. We show that unfortunately there exists a standard fuzzy metric space that dose not admit any completion. Also we show that for each completable standard fuzzy metric space there is a unique completion up to F-isometry. The compact standard fuzzy metric spaces and F-totally bounded are defined then we proved that F-totally bounded complete standard fuzzy metric space is compact. Moreover the continuous and uniform continuous functions on a compact space is studied to prove that continuous functions and uniform continuous functions are equivalent on compact standard fuzzy metric spaces. At this end the notion of standard fuzzy pseudo metric space is introduced to prove that the completion of standard fuzzy pseudo metric space is a standard fuzzy metric space. The definition of standard fuzzy quasi metric space is introduced then an internal characterization of those standard fuzzy quasi-metric space that admit a bicompletion is given, we also show that such a bicompletion is unique up to F-isometry. Finally the fuzzy distance between a compact set and a point is defined as an introduction to define the fuzzy distance between two compact sets then a method for constructing a Hausdorff standard fuzzy metric on the set of the nonempty compact subset of a given standard fuzzy metric space is proposed. At this end we proved that if the given standard fuzzy metric space is complete then the Hausdorff standard fuzzy metric space is complete.

بعض الخوارزميات لتقريب مسائل التغاير

By: أسماء عبدالاله عبد الرحمن   Supervised By: أ.م.د. سهى نجيب شهاب   year: 2012

Abstract

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This thesis presents a number of algorithms for the approximate solution of variational problems based on first and second Chebyshev wavelets. The convergence of second. Chebyshev wavelets are first discussed. Then some new relations between first and second Chebyshev wavelets are derived. The proposed algorithms to find extremum value of variational problem are based on using Euler-Lagrange equation. To facilitate the computation, a new property is derived called operational matrix of derivative. Using the operational matrices of derivative and integration, for first and second Chebyshev wavelets. The problem is converted to solving a system of algebraic equation. All algorithms are tested on a variety of problems.

The Artin's Exponent of A Special Linear Group SL(2,2k)

By: Lemia Abd Alameer Hadi   Supervised By: Prof.Dr.Mohammed Serdar I.Kirdar   year: 2008

Abstract

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The set of all n×n non singular matrices over the field F form a group under the operation of matrix multiplication, This group is called the general linear group of dimension n over the field F, denoted by GL(n,F) . The subgroup from this group is called the special linear group denoted by SL(n,F) . We take n=2 and F=2k where k natural, k>1. Thus we have SL (2,2k). Our work in this thesis is to find the Artin's exponent from the cyclic subgroups of these groups and the character table of it's. Then we have that: a SL(2,2k ) is equal to 2k-1 .

Artin's exponent for any arbitrary characterS of finite special linear groups

By: Simaa hassan Aziz   Supervised By: prof.dr.mohammed serdar i.kiradar   year: 2008

Abstract

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The main purpose of this work is to find the Artin exponent of finite special linear groups from any arbitrary characters of cyclic subgroups of these special linear groups and denoted by: a (SL(2, p)) Where p is any prime such that p ≥ 5, and we found that a (SL (2, p)) is equal to 2.

ON FUZZY HILBERT SPACES

By: Raghad Ibrahim   Supervised By: Dr.Jehad R. Kider    year: 2008

Abstract

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In this thesis we recall the definition of a fuzzy metric space and the definition of fuzzy normed space then the related concepts are discussed, much attention is paid to the concept of fuzzy completeness. Also we recall the definition of fuzzy inner product space and give some new results after introducing new concepts such as fuzzy convergence; fuzzy Hilbert spaces then we prove that if A ̃ is any fuzzy closed subspace of a fuzzy Hilbert space H then H =(A ) ̃⊕Z ̃ where Z ̃= A ̃^⊥. Finally we introduce fuzzy Hilbert dimension after that we prove that two fuzzy Hilbert spaces H and G both real or complex are isomorphic if and only if they have the same fuzzy Hilbert dimension.

Spectral Method for Continuous Optimal Control Problems with Chebyshev Polynomials

By: Jabbar Abed Eleiwy   Supervised By: Dr. Suha Najeeb Shihab    year: 2008

Abstract

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This thesis is concerned with the approximate solutions of finite quadratic optimal control (QOC) problems that are governed by ordinary differential equations which represent the constraints. The proposed method is classified as indirect methods which are usually based on the necessary optimality conditions. Besides necessary conditions, sufficient condition has to be checked to ensure the optimality of the solution. The result by applying these conditions is two points boundary value problem (TPBV). In this work very efficient algorithms are proposed, which are based on applying the idea of spectral method using the Chebyshev polynomials: which include Chebyshev polynomials of the first kind, Chebyshev polynomials of the second kind and shifted Chebyshev polynomials of the first kind. To facilitate the computations, new properties of Chebyshev polynomials are derived. Finally, the proposed algorithms have been applied to several examples.

Using Fractals In Information hiding

By: Thenaa Ali Kadhum   Supervised By: Dr. Nadia M. G. Al- Sai'di    year: 2008

Abstract

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In this thesis we introduce a new method for hiding information as images then decrypt them to find the message. Many of us lump cryptography with Steganography, it's true that the later is a way to encrypt the information, but still there are differences. These differences will be cleared in this thesis. We suggested a method to hide the information by the self similarity patterns of fractals, using the affine transformations to create the image as the attractor of the iterated function system. The privilege of the IFS is that we can send long messages, as just one image. That is by embedding the information as a text in an image and extracting it. Decoding the attractor by Barnsley's collage method is to find the values of the coefficients that created the image, that in fact are the letters of the message that are hidden in an innocent colored image.

Development Of Lagrange’s Method To solve Linear Programming Problems

By: Owse Nidhal Thiab   Supervised By: Associated prof. abbas Ahmed Hassan   year:2008

Abstract

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The aim of this study is to develop Lagrange’s method for the solution of linear programming. Throughout this study many of methods have been carried out to find out the optimal solution for the linear programming problems as the simplex method and Lagrange’s multiplications method and the method of normal Kuhn – Tucker‘s conditions. We have studied Lagrange‘s method and throughout several derivations, we came to a conclusion to mathematical forms by which it can be possible to get to the solution without doing long derivations. The form we obtained is much better than normal Lagrange method .thus; we can avoid a lot of derivations and summarize the number of probabilities of eradicating some of the changeable items which had rapidly got to the optimal solution.

An Approximate Solution of Some Continuous Time Linear-Quadratic Optimal Control Problem via Generalized Laguerre Polynomial

By: Hala Rahman Gaber   Supervised By: Dr. Suha N. AL-Rawi   year:2007

Abstract

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This thesis is concerned with the approximate solution of finite linear quadratic optimal control problem that are governed by a system of ordinary differential equation. The proposed method is classified as direct method, which is employed by using special technique to convert the LQOC problem into a quadratic programming problem. It is based on generalized Laguerre polynomials as a basis functions to aproximate the system state variables by a finite length of the basis functions series of unknown parameters. Furthermore, some important formulas which are concerned the generalized Laguerre polynomials are derived and proved as essential in the proposed method. Finally, the proposed algorithm was illustrated by several examples.

ON SOLOMON THEOREM Of RATIONAL VALUED CHARACTERS

By: Maysoon Mahmood Kaittan   Supervised By: Prof.Dr.Mohammed Serdar I.Kirdar   year: 2007

Abstract

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The main Theorem in this work is Solomon Theorem which states that the factor group (R(G))/(T(G)) has a finite exponent dividing |G| . The theorem study the relation between ch'QG, the subring of chG generated by the set of rational valued characters of G and ch'QG generated by characters defined by certain families of subgroups of an arbitrary finite group G. This result has several applications including an extension to ch'QG of the Artin's Induction Theorem in which these certain families of subgroups are cyclic. Lam determined that the last positive integer A(G) such that A(G) χ is an integral linear combination of the induced principal characters of cyclic subgroups, for any rational valued character χ of G, A(G) is called the Artin exponent of G. The main objective of this thesis is to find the Artin Exponent of the Special Linear Groups SL(2,2k), k natural, by the aid of Solomon Theorem of Rational Valued Character. It is found that the Artin Exponent, A(G), of G =SL(2, 2k), k natural and k >1, is A(G) =2K-1. and A(SL(2,2k) ) = 2 , when k = 1

Computational Methods for Solving Special Type of the Integral Equations

By: Khawla Abdul-Hussein Al-Zubaidi   Supervised By: Ass.Prof.Dr.Omar Mohammed AL-Faour    year: 2006

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This thesis is concerned with the analytic, numerical and approximate solutions of linear Fredholm integral equation of the second kind. The proposed numerical methods are based on the extrapolation procedure coupled with closed Newton-Cotes formulas, while the approximate methods in this work are employed by using variational technique with different types of basis functions including: algebric polynomials, Legendre polynomials and Chebyshev polynomials. In this technique, we may find many functions for every linear Fredholm integral equation of the second kind whose minimum is the solution of the problem. Furthermore, the proposed algorithms have been applied for several examples. We find the proposed methods produce satisfactory results.

Numerical Treatments of System of Fredholm Integral Equations

By: Ghada Hassan Ibrahim   Supervised By: Dr.Omar Mohammad AL-Faour    year:2006

Abstract

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The main aim of this thesis is to study and modify some approximate and numerical method to treat linear system of Fredholm integral equations. For the approximate method for solving linear system of Fredholm integral equations including Neumann Series method have been modified to be applicable for solving this system. Also, the existence and uniqueness theorem for the Fredholm integral equation has been generalized to system of Fredholm integral equations. Moreover, five different types of Nystrom or quadrature methods “Trapezoidal, Simpson’s 1/3, Simpson’s 3/8, Bool’s and Weddel’s” have been modified and successfully employed to give numerical solution for this system. Also, the convergence theorem of the Nystrom methods and the error analysis for the single Fredholm integral equation has been generalized to linear system of Fredholm integral equations. This thesis presents five algorithms based on extrapolation method including: Trapezoidal extrapolation, Simpson’s 1/3 extrapolation, Simpson’s 3/8 extrapolation, Bool’s extrapolation and Weddel’s extrapolation to get more accurate results. Finally, at the end of each methods, Algorithms and programs developed and written in MATHLAB (version 6.5).

Numerical Solutions and Algorithms for Optimal Control Problems

By: Saba Sattar Hassen   Supervised By: Dr.Suha N. AL-Rawi   year: 2006

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This thesis presents some approximate solutions to both linear and nonlinear quadratic optimal control problems that are governed by a system of ordinary differential equations which represent the constraints. The proposed method is classified as direct method which is employed by using state vector parameterization (SVP) to convert the quadratic optimal control problems into quadratic programming problem. The state vector parameterization is based on spline polynomials including: B-spline and Catmull-Rom spline as basis functions to approximate the system state variables by a finite length of the basis functions series of unknown parameters. Furthermore, some important formulas concerning the spline polynomials are derived and proved which are essential in the proposed method. Finally, the proposed algorithms have been applied for several examples giving satisfactory results.

Numerical Solution of Two-Points Boundary Value Problem

By: Bushra Eesa AL-Robeay   Supervised By: Dr. Omar Mohammad AL-Faour    year:2006

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This thesis is based on solving both linear and nonlinear two-points oundary value problem TPBVP using some numerical and approximate methods. Newton-Kantorovich method is used to convert the nonlinear TPBVP into linear boundary value problem. The numerical methods are based on finite difference and Numerov difference methods. The mathematical study of convergence and stability of these methods are introduced. Furthermore, the idea of the extrapolation technique coupled with the proposed numerical methods is applied to solve TPBVP. In addition, the weighted residual method including collocation and Garlekin's methods are applied to solve the above problems approximately with two basis functions: power polynomial and Chebyshev polynomials. Finally, some numerical examples show that the proposed methods give satisfactory results.

A COMPARISON STUDY OF IMAGE CODING Algorithms

By: Enass Hamudi Kareem   Supervised By: Dr. Matheel Emad AL-Deen Abdlmunim   year: 2006

Abstract

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Image processing can be considered as an essential part of wide range computer application. In the last decade, the wavelet transform has diffused in most digital signal processing applications, where it plays a very important role in image processing analysis. This thesis deals with image coding. Image coding using Huffman or run length code does not use transform. Moreover image coding using threshold or zonal code is using transforms to code images. Two types of transforms Discrete Cosine Transform (DCT) or Discrete Wavelet Transform (DWT) have been used after segmenting the image into blocks, and then Zonal coding algorithm or threshold coding algorithm is used to get the coded image. As result the (DWT) gives better results than (DCT), where the Mean Square Error (MSE) in DWT is less than the MSE in DCT, which gives us a conclusion that using wavelet transform is better than other transforms when it is used for image coding. Also, the threshold coding gives better results compared with zonal coding. The performance of proposed methods has been evaluated by computer simulations using MATLAB 7.0 language and performed on personal computer Pentium_4 with 2.4 GHZ processor, 40 GB hard disc and 256MB main memory.

ON HIGHER DERIVATIONS AND HIGHER HOMOMORPHISMS OF PRIME RINGS

By: Anwar k. Faraj    Supervised By:    year: 2006

Abstract

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Let R be a ring not necessarily with an identity element. A wellknown result proved by I.N.Herstein concering derivations in prime rings have been extensively studied by many authors like, M.Bresar, N.M.Shammu and M.Ashraf and N.Rehman. Also, C. Haetinger and M.Ferro extended this result to higher derivations. The main purpose of this work is i. Extend N.M.Shamm's theorem to higher N-derivations by giving the concept of higher N-derivation. A higher Nderivation of a ring R is defined as a family of additive mappings of R into itself , for all u∈U, r,s∈R , n∈N,where U is a Jordan ideal of R. ii. We answer the question of C.Haetinger and W.Cortes whether the result of C.Haetinger and M.Ferro is also true for Jordan generalized triple higher derivations. iii. We introduce the concept of (U,R) derivations and generalized (U,R) derivations. Then we extend Awatar's theorem and we extend this result to higher (U,R) derivations and generalized higher (U,R) derivations by giving corresponding definitions. A well-known result of I.N.Herstein concerning Jordan homomorphism and Jordan triple homomorphism has been extensively extended by M. Bresar. Also R.C. Shaheen extended these results to generalized Jordan homomorphism and generalized Jordan triple homomorphism iv. We introduce the concepts of higher homomorphism, Jordan homomorphism and generalized Jordan triple homomorphism and their generalization and we extend the above results and study these concepts onto 2-torsion free prime ring.

Expansion Methods For Solving Linear Fractional Integro-differential Equations

By: Ahmed Mohammed Shucker   Supervised By: Dr. Suha N. AL-Rawi    year: 2006

Abstract

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This thesis presents some Expansion methods for solving linear fractional integro-differential equations of both Fredholm and Volterra types. The expansion method is associated with the weighted residue techniques including the following methods: collocation, least squares and Galerkin which have been used to treat the above problems. In addition two orthogonal functions: Chebyshev and Legender as well as two spline functions: B-spline and Catmall-Rom spline have been used as a basis functions to approximate the unknown function within the proposed approximated methods. Some new formulas of fractional derivatives for each Chebyshev, Legender, B-spline and Catmall-Rom spline functions have been derived which are very useful in simplifying the computations in this work. Moreover, the convergence and stability of all approximated methods are investigated. Additionally, the proposed methods have been applied to several examples with satisfactory results and a program for each method is written with the aid of MATLAB version (6.5).

NUMERICAL METHODS FOR A SYSTEM OF LINEAR VOLTERRA INTEGRAL EQUATIONS

By: Sumaya Abdul Abaas Saify    Supervised By:Asst.Prof.Dr. Omar Mohammed Al-Faour    year: 2005

Abstract

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The main aim of this thesis is to study and modify some analytic and numerical methods to treat a system of linear second kind Volterra integral equations. For the analytic treatment two methods for solving single Volterra integral equation including Laplace transform and successive approximation method have been modified to be applicable to solve the system. Runge-Kutta methods including: Runge-Kutta second order, Runge-Kutta third order and Runge-Kutta of fourth order have been modified to give numerical solution to this system and study the convergent of the algorithms of Runge-Kutta methods. In addition, block methods which include: method of two, three and four blocks have been used to find numerical solution to this system. The package “NSSLSKVIE” is constructed to find the numerical solutions to system of linear Volterra integral equations using all the above methods. Finally, at the end of each method, algorithms and programs are developed and written in MATLAB (Version 6.5).

Study and Development The Solution of Linear Programming problems with Free Variables

By: Rasheed Basheer Reheima   Supervised By: Associated Prof. Abbas Ahmed Hassan    year: 2005

Abstract

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The objective of this thesis is to study and development the solution of linear programming problems with free variables. This thesis studied number of methods with its algorithms to solve the above problems. The thesis studied one of classical methods which expressed any free variable as a difference between two nonnegative variables, then the modified MPS method is studied which expressed any free variables as a function of remaining nonnegative variables . It is found that MPS method is better than classical method, since MPS method reduced the tables number, make the calculations easier and reduced the solution time. Also MPS method used some basic theorems to determine the solution result for some problems from the initial table with out depending on the problem detail solution . This thesis also includes appendix represented the package programs with Visual Basic language (Microsoft Visual Basic 6.0), to get a good forms of display at execution and solving all the problems that may be found in this scope to apply all methods that included in this thesis.

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