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 (50-250C) 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 250C 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
Abstract
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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
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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
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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
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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
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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
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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
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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).