Show: 25 50 75 100 Results

Search results: 25 out of 948

التاثير التثبيطي لزيت الحبة السوداء والعسل على التاثير السمي الوراثي لعقار التاموكسفين == Inhibitory Effects of Nigella sativa Oil and Honey on the Genotoxicity of Tamoxifen in Mice

Author name: ايات منعم علي السوداني
Supervisor name: Khulood Al-Samarraee | Esmail K.Shubber
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

دراسة بكتريولوجية ووراثية على عوامل الضراوة لبكتريا Klebsiella pneumoniae المعزولة من التهابات القناة البولية == Bacteriological and Genetic Study on Virulence Factors of Klebsiella pneumonia Isolated from Urinary Tract Infections

Author name: مهند رضا مهدي ال شكر
Supervisor name: Majed H. Al-Gelawi
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

دراسة الفعالية البيولوجية لمستخلص الشاترك == Biological Study on the Activity of Fumaria officinalis Extracts

Author name: مهند حسن حسين العزاوي
Supervisor name: Khulood W. Al-Samarraei | Alice K. Melconian
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

دراسة بعض التغيرات الكروموسومية الناتجة عن التلوث بالاوكراتوكسين A في الفئران == Study of Some Chromosomal Variations Caused by Ochratoxin A Contamination in mice

Author name: نور الحكم حسن علي التكريتي
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

تاثير بكتريا حامض اللاكتيك على المسببات البكتيرية لمرض حب الشباب الالتهابي الشديد == The Effect of Lactic Acid Bacteria on Bacterial Causes of Severe Acne Vulgaris

Author name: رنا قاسم نعيم الدليمي
Supervisor name: Abdul W. Baqir | Hussain M. Ghazi
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

دراسة الفعالية البايولوجية خارج الخلية لمستخلص Pleurotus oyster == In vitro Study of Biological Activity of Pleurotus oyster Extract

Author name: علياء سعد عبد كركوش
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

تاثير Probiotic على عوامل الحركة وظاهرة الانثيال لبكتريا Proteus mirabilis == Effect of Probiotic on Motility Factors and Swarming Phenomenon of Proteus mirabilis

Author name: ريم وليد يونس زين العابدين
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science - Department Of Biotechnology
Language: English
University location: Baghdad
First pages:

تاثير Probiotic على بكتريا Proteus mirabilis وصفتها الالتصاقية

Author name: غيداء حسين عبد الرحيم الجبوري
Supervisor name: Abdul W. Baqir
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science
Language: English
University location: Baghdad
First pages:

التمييز بين الذكور والاناث لنبات الهوهوبا خارج وداخل الجسم الحي باستخدام تقنية ال PCR == Molecular Differentiations of simmondsia chinensis

Author name: جميل ربيع جميل العبيدي
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science
Language: English
University location: Baghdad
First pages:

دراسة تاثير مستخلصي ازهار نبات القيصوم داخل وخارج الجسم على الخصوبة في ذكور الفئران == In vivo and in vitro Study on the Effects of Achillea millefolium Flower Extracts on Fertility in Mice Male

Author name: ضفاف يوسف يعقوب بطي
Supervisor name: Khulood Al-Sameraei | Mohammed A. Ibrahim
General topic: Biology
Specific topic: Biotechnologies
Degree: Master
University: Al-Nahrain University - College Of Science
Language: English
University location: Baghdad
First pages:

تحضير ودراسة خواص الفصل لطور ثابت جديد لتقنية HPLC == PREPARATION AND CHARACTERIZATION OF NEW HPLC STATIONARY PHASE

Author name: هاجر سعد نجم
Supervisor name: شهباز احمد مكي
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Chemistry Department
Language: English
University location: Baghdad
First pages:
Abstract: prepared by the reaction of congo red solution with amberlite anion exchange.SUMMaRYThe F.T.I.R elemental analyses have configured the attachment of congo red on the resin as has indicated by the physical appearance of the new resin.The resin capacities of newly prepared resin has calculated the resin capacity for the amberlite - congo red resin was found to average 7.36 meq/ gm and for the amberlite resin 3.0 meq./gm.The new stationary phase has been packed into stainless steel column. This has been done by the special technique. The chromatographic performance of the packed column was characterized the number of plate numbers, height equivalent of a theoretical plates(HETP) capacity factors, selectivity factor and peak asymmetry were measured by analyzing different analysis on the new column using different mobile phases composition and flow rates. The parameters were measured from analysis of some amino acids such as phenyl alanine, tyrosine and tryptophan. The analysis of amino acids using amberlite - congo red column has performed with an aqueous mobile phase adjusted at pH 10. The average number of plates, N was(111.09 - 284.3) . The plate height H was (0.01343) cm, capacity factor, ḱ were ranged from(3.5 - 3.76). and peak asymmetry value was1.06. The analysis of some amino acid of the some column but with a mobile phase adjusted at pH 10 with 20% aceto nitrile, the chromatographic parameters were plate’s number, N was(176.3307). plate height H was(0.128) cm, capacity factor Ќ were ranged from(2.98 - 4.65).

تصميم مراة ايونية تعمل كمصحح للزيوغ باستخدام طريقة القيم الحدودية == DESIGN OF ION MIRROR AS AN ABERRATION CORRECTOR USING BOUNDARY VALUES METHOD

Author name: محمد سلام مزاحم العبيدي
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:

تصحيح الزيغ بسبب عدم التراصف في العدسات الكهروسكونية == THE ABERRATION CORRECTION DUE TO MISALIGNMENT IN ELECTROSTATIC LENSES

Author name: رؤى تحسين عبد الله الصميدعي
Supervisor name: احمد كمال احمد
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: اجري بحث حاسوبي في مجال بصريات الجسيمات المشحونة. يهتم البحث بتصميم منظومات عدسات كهروسكونية بوجود وعدم وجود تاثير عدم التراصف تعمل تحت ظروف تكبير مختلفة.ان توزيع مجال الجهد لعدسه احادية الجهد وعدسة مغمورة كهروسكونية تم تمثيله بدوال تحليلية. تم حل معادلة الاشعة المحورية للمجالات المقترحة لايجاد مسار الجسيمات المشحونة المارة في كل عدسة. ومن توزيع الجهد المحوري ومشتقتيه الاولى والثانية .تم حساب الخواص البصرية كالبعد البؤري والزيغين الكروي واللوني. كذلك تم ايجاد شكل اقطاب كل عدسة كهروسكونية ببعدين وبثلاثة ابعاد. ويعتمد الزيوغ في العدسات الكهروسكونية اعتمادا كبيرا على تراصف الاقطاب، وقد وجد انه عامل مهم يؤثر على الشكل الهندسي لمنظومة العدسة الكهروسكونية. ان نتائج هذه الدراسة لا تبرهن نظريا" امكانية تصميم منظومات عدسة كهروسكونية بزيوغ واطئة فحسب بل تبين امكانية تصنيع مثل هذه العدسات عمليا". | A computational investigation has been carried out in the field of charged - particle optics. The work is concerned with the design of electrostatic lenses with and without misalignment effect operated under different magnification conditions. The potential field distributions of einzel and immersion electrostatic lenses have been represented by analytic functions. The paraxial ray equation has been solved for the proposed fields to determine the trajectory of the charged particles traversing each lens. From the axial potential distribution and its first and second derivatives, the optical properties such as the focal length and spherical and chromatic aberrations have been compute. The electrode shape of each electrostatic lens has been determined in the two - and three - dimensions. The aberration of the electrostatic lens is highly dependent on the alignment of the electrodes and it has been found to be an important parameter affecting the geometry of the electrostatic lens system. The results of this investigation not only prove in theory the possibility of designing electrostatic lens systems with low aberration but also show the possibility of constructing such lenses in practice

دراسة النشاط الاشعاعي لنماذج من التربة والماء في بغداد وكربلاء والبصرة == Determination of the Radioactivity in Soil and Water in Baghdad, Karbala and Basrah Samples

Author name: مصطفى عرب بداي علي البيضاني
General topic: Physics
Specific topic: Solid State and Materials Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: يتضمن البحث دراسة عملية لتحديد تراكيز اليورانيوم وغاز الرادون في التربة والماء لمناطق من بغداد وكربلاء والبصرة وللتعرف على مدى تلوث تلك المناطق بالمواد المشعة بعد احداث الحرب على العراق عام 2003 .تضمن الجزء الاول ايجاد تراكيز اليورانيوم في التربة والماء باستخدام كاشف الاثر (CR - 39) حيث استخدم التفاعل U - 235(n,f)U - 236 كمصدر لشظايا الانشطار النووي وذلك بقصف نواة اليورانيوم U - 235 بالنيوترونات الحرارية من المصدر النيوتروني (Am - Be) بفيض نيوتروني حراري (5 ×103 n cm - 2 s - 1) .تم تحديد التراكيز بالحسابات المعتمدة على المقارنة مع النماذج القياسية، وقد اوضحت النتائج التي حصلنا عليها ان اعلى تركيز لليورانيوم في التربة (2.73 ppm) في منطقة التاجي واعلى تركيز لليورانيوم في الماء (2.12 ppm) في منطقة العشار. تضمن الجزء الثاني ايجاد تراكيز غاز الرادون في التربة والماء باستخدام تقنية عد اثار جسيمات الفا المنبعثة من غاز الرادون فيكاشف الاثر (CR - 39) .وقد اوضحت النتائج التي حصلنا عليها ان اعلى تركيزلغاز الرادون في التربة (666 Bq/m3) في منطقة التاجي واعلى تركيز للرادون في الماء (14 Bq/m3) في منطقة العشار. اوضحت النتائج التي حصلنا عليها بان اعلى تراكيز لليورانيوم والرادون كان في منطقة التاجي ببغداد وفي منطقة العشار بالبصرة بسبب كون تلك المناطق مسرح للعمليات الحربية ضد العراق عام 2003 . | The aim of this project is to measure the uranium and radon gas concentrations in soil and water samples taken from regions situated in Baghdad, Karbala and Basrah, and to limit the level of contamination with radionuclides for these regions during the 2003 war.The first part contains the determination of uranium concentration in soil and water samples using CR - 39 Track detector. The nuclear reaction used a source of nuclear fission fragments is 235 - U (n , f) obtained by the bombardment of U - 235 with thermal neutrons from (Am - Be) source which has flux of (5 ×103 n cm - 2 s - 1). The concentrations values were calculated by a comparison with standard samples which prepared in our laboratory.The results obtained show that the higher concentration of uranium in soil samples was (2.73 ppm) in Al - Tajii region, and the higher concentration for water samples was (2.12 ppm) in Al - Ashaar region.The second part contains the determination of radon concentration in soil and water samples using alpha - emitters registration which emits from radon gas in (CR - 39) track detector.The results show that the higher concentration for radon gas in soil samples was (666 Bq/m3) in Al - Tajii region and in water samples was (14 Bq/m3) in Al - Ashaar region.The results show the maximum values of uranium and radon concentrations were in the (Al - Tajii and Al - Ashaar) regions, because these regions were a field of military operations during the 2003 war

نظام اخفاء البيانات ذو معدل اخفاء عالي باستخدام تحويل الافين وطريقة البت الاقل اهمية == High Hiding Rate Image Steganography System Based On Affine Transform and LSB Method

Author name: محمد خليل خلاف سهيل القيسي
Supervisor name: لؤي ادور جورج | اياد عبد العزيز العاني
General topic: Physics
Specific topic: Solid State and Materials Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: The spying and intrusion operation had been widely spread to steal the information especially with the development of computer networks (like, Internet). To prevent this danger the development of a new technology called “digital information hiding” was developed in such a way that the intruder cannot notice the existence of secret information in the media.In this project an image steganograph system is introduced. The proposed system is based on using the affine transform to represent the blocks of the secret image in terms of the blocks of the cover image. Then, the least significant bits (LSB) insertion method is utilized to hide the quantized affine transform coefficients of the secret image in the cover image. Also in this research some block indexing methods are utilized to improve (i.e, speed up) the involved trials of affine mappings. Three systems (they are traditional IFS, IFS with symmetry predictions, and IFS with symmetry prediction and blocks indexing) have been established. They used to manage the way of selecting the suitable domain (cover) to represent the range (secret) block. The domain search operation will not need to make all isometric - block tests on each domain block. The best domain isometric state is assessed using the introduced isometric predictor; which is based on the moment status of the matched block. This will significantly reduce the matching time because only one match, instead of eight, will be tested to evaluate the IFS - similarity between any range and domain block. Also, a block indexing method is introduced to filter the domain blocks, and filter - in only those domain blocks that have similar block index with that of the mapped range block to be tested using IFS - matching.Some of the well known fidelity measures (like, MSE and PSNR) have been used to asses the quality of the reconstructed image. The conducted test results indicated that the proposed improvements have reduced the required hiding time down to 6.81 second (around 80 times in comparison with the traditional scheme) without making significant degradation in image quality

تاثير نسب ومعاملات الحزم على دقة تصنيف صور الاقمار الصناعية المتعددة الاطياف == Effect of Band Ratios and Indices on Classification Accuracy of Multispectral Satellite Images

Author name: سيف كامل شنين
Supervisor name: اياد عبد العزيز العاني | صلاح عبد الحميد صالح
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: Multispectral satellite images are holding whole information about the areaunder investigation. Many of digital processing techniques are used to extractmost of the possible information from these images, such these techniques arespectral band ratios, Tasseled Cap transformation and Principle ComponentAnalysis (PCA). These techniques are play good part for features extraction andreducing the number of spectral bands with no loses in information.The research aims to apply classifications on band ratios and image indiceswhich include PCA and Tasseled Cap transformations, of Enhanced ThematicMapper Plus (ETM+) satellite images, and to show how the accuracies of theclassification are differ from the accuracy of classification of the raw ETM+ bandsimages.The results show that the best bands ratios that adopted to represent fiveselected land features are 5/7, 4/5, 2/5, 1/4, and 2/4. Optimum Index Factormethod (OIF) has been adopted on raw bands combinations, and on the bandsratio combinations to select which band combination that contains muchinformation, where the results show that the best combination for raw bands is3 - 4 - 7, and best combination for ratios band is 4/5 - 1/4 - 2/5.Iterative Self Organizing Data Analysis (ISODATA) method has beenadopted as unsupervised classification, and Maximum Likelihood method assupervised classification. The overall accuracies are 87.18%, 89.45%, 89.26%,and 89.52% for raw bands, band ratios, Tasseled Cap, and PCA respectively,which showed that transformation techniques give good spectral enhancementsand feature extraction which are undistinguishable in raw image, and representgood tools to increase the accuracy of classification.

دراسة متانة الربط الانتشاري بين السيراميك والمعادن في الحالة الصلبة == Investigation of the Relaibility of Diffusion Bond Strength Between Ceramic - Metals in Solid State

Author name: اروى غازي ناجي الطائي
Supervisor name: زاريه ازات سركيس | ثامر عبد الجبار جمعة
General topic: Physics
Specific topic: Solid State and Materials Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:

دراسة تعجيل الالكترونات باستخدام تفاعل الليزر مع البلازما الممغنطة للاتصادمية == Study of Laser Acceleration of Electrons in a Magnetized Collisionless Plasma

Author name: امال محمد كنيوي العكايشي
Supervisor name: خالد عباس يحيى | محمد عبد الزهراء حبيب
General topic: Physics
Specific topic: Electronics Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: A theoretical and computational investigation was carried out in the field of laser - plasma interaction using the Finite Difference Method to study the acceleration of electrons with non - relativistic velocities in a non - magnetized and magnetized collisionless plasmas.First, a (Nd : YAG) laser pulse of 25 fs duration and 5x1015 W/cm2 intensity was assumed in the present study.When this laser pulse was allowed to interact with a stationary electron in vacuum, it was found that the electron is accelerated during the interaction only and returns to stationary state after the laser pulse has passed, in agreement with previous works.Also, the interaction of the same laser pulse with a collisionless plasma at electron density ne= 1x1018 cm - 3 was studied. It was noticed that the energy of the electron during the interaction has reached a maximum value of ~ 1 keV at laser pulse intensity of 5x1015 W/cm2, while the energy of the electron after the interaction reached ~ 15 eV for the same laser pulse intensity.Finally, the interaction of the same laser pulse with a plasma was studied at electron density ne=1x1018 cm - 3 in the presence of an external magnetic field for the three values of the field strength B= 60 MG, 70 MG and 80 MG. It was found that there is an increase in the acceleration of the electron to reach a maximum energy of ~ 19 keV at a laser pulse intensity of 5x1015 W/cm2 and an applied external magnetic field strength of 80 MG during the interaction. However, the electron energy after the interaction reached ~ 3 keV at a laser pulse intensity of 5x1015 W/cm2 and an applied external magnetic field strength of 70 MG. This is due to a sustainable generated laser wakefield of ~ 2x109 V/cm. Thus, it is concluded that an applied external magnetic field assists the acceleration of the electron and can subsidize for a high laser beam intensity

محاكاة العين البشرية باستخدام الخوارزمية الجينية == SIMULATION OF HUMAN EYE USING GENETIC ALGORITHEM

Author name: لؤي عبد الصاحب رسول الطائي
Supervisor name: سهى موسى خورشيد الاوسي | محمد صاحب الطائي
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: The aim of this research is simulate an optical system for the human eye using Genetic algorithm. The considered optical characteristics of the optical system simulator include spot size (Z), spot diagram, and effective focal length (EFL). These characteristics are determined with the aid of some mathematical relations, which give the efficiency and accuracy of the adopted optical system design. The work has been performed in two stages : In the first stage, Genetic Algorithem optimization (GA) is used to get the best design by optimizing the optical featurs of the eye elements. The optimal eye design was tested using Zemax software, the test includes estimation of the image quality, and optimal performance for the proposed optical eye system.The second stage was implementing a specially developed software to simulate the behavior of the human eye. The simulator using visual basic 6 and works under Windows operating system, it is able to plot the eye design graphically, and can estimate the considered optical functions to determine the efficiency of the eye simulator.The simulator showed agood results for spot size, spot diagram and EFL, the present work has been gained some credibility when the considered optical functions achieved by the simulator are found compatible with those achieved by Zemax, since the comparison showed a behavioral matching between them, which ensure the correct path of the GA based eye design and the successful proposed eye design.

دراسة الفجوات المصنعة بهيئة عيوب بواسطة الاشعة السينية لمصبوبة المنيوم ومفاصل لحام الفولاذ == X - ray Radiographic Study of Simulated Voids - Like Defects in Aluminum Casting and Welded Joints in Steel

Author name: فرقد رشيد سعيد الزبيدي
Supervisor name: مازن فضيل محروك | ثامر عبد الجبار جمعة
General topic: Physics
Specific topic: Solid State and Materials Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: This project investigates the detection and evaluation of imperfections in internal structures of castings and welded joints by x - ray radiography. Optimum radiography conditions that lead to clear and high contrast image on the radiograph were studied.Equations derived earlier for finding the size and depth of defects in castings were used in this project to test their applicability to a wide range of geometrical parameters used in radiography.The importance of non - destructive testing NDT in industry is discussed. X - ray radiography being one of the NDT techniques, has some privilege over other techniques. For example, welded joints sometimes contain internal flaw or blowholes that may escape detection by other NDT techniques but can not escape detection by x - rays. Two kinds of samples are prepared for radiography. The first sample is aluminum casting through which two different sizes of steel spheres are included. This sample was radiographed from two opposite sides and the x - ray films were analyzed.The second sample is steel plates which are welded by arc welding and then radiographed by x - rays.Imperfections in this sample such as incomplete root penetration, undercut and porosity were detected by x - ray radiography. Different conditions influencing the preparation and radiography of the above samples were studied. The prepared welded sample was radiographed three times for different high voltages (120,140,160) kV respectively with an exposure time of (80) second. The best quality image where the defects can be detected clearly if its size is (5%) of the radiographed object using (120) kV and (140) kV. Moreover the results show that the optimum film gradient was found at (140)kV and the contrast is better than obtained with (120)kV while darkening image was found at (160)kV.In field of the aluminum casting, the two equations were derived earlier proved their capabilities as a right method for identification each of size and depth of such defects in castings and welded joints

دراسة قدرة الايقاف والمدى للبروتونات == Study of Stopping Power and Range for Protons

Author name: مصطفى عبد المحسن عبد العالي
Supervisor name: محمد احمد صالح
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: The calculation of the value of stopping power and the range for the proton is done by two ways : first, using Bethe - Bloch formula and second, using Bragg - Kleeman rule. The differences between the experimental and theoretical values of stopping power and range required studying the corrections for Bethe - Bloch formula which are represented by the maximum energy and density correction and then comparing the results with experimental values. Using these two formulas it has been found that the results computed by the Bethe - Bloch formula without corrections (maximum energy and density correction) are in agreement with experimental results for βγ ≤ 2 ( E ≤ 2×103MeV ) and for βγ ≤ 102 ( E ≤ 105MeV ) with corrections. The maximum energy and density corrections contributed to decrease the difference with the experimental results for βγ ≥ 102 ( E ≥ 105MeV ).The values of stopping power computed using the Bragg - Kleeman rule are in agreement with experimental results for E ≤ 200MeV and the range values computed using the Bragg - Kleeman rule are in agreement with the results computed using the Bethe - Bloch formula for E ≤ 400MeV .The results show that the energy losses for protons at the high energy values are low and vise versa; the energy losses for protons at the low energy values are high.The present calculations confirm that the proton looses its largest energy at the end of its path in matter

تاثير المعاملة الحرارية على بعض الخواص الميكانيكية للمتراكب المنيوم - كاربيد البورون == Effect of heat treatment on some mechanical properties of Aluminum - Boron carbide composites

Author name: لمى جمال عباس الرماحي
Supervisor name: قاصد عبد الستار صالح الجنابي | سعد رحمة الله
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: Aluminum matrix composites reinforced with boron carbide are currently employed in the nuclear industry. It's used as a control rod in nuclear reactors; Since B4C has very high absorption cross section for thermal neutrons. The objective of this work is to study the effect of heat treatment on the mechanical properties of the Al - B4C metal matrix composites prepared by powder metallurgy techniques. Compressibility was measured with the Al powder. The chosen compaction pressure was 2500psi. Samples were prepared by adding 5%, 10%wt B4C to Al as well as the Al powder. Sinterability was evaluated at different temperatures (400,450,500,550,600,650°C) during 2, 4, 6, 8; 10 hr for soaking time.Mechanical test were evaluated, showed little improvement in hardness, compressive strength and young's modulus in temperatures 400,450,500,550°C, and significant improvement in hardness and compressive strength in temperatures 600and 650°C, and also improvement to the elastic modulus. Specific samples were irradiated by neutron source, and mechanical tests showed little decrease in their mechanical properties (hardness and compressive strength) due to low neutron fluence available that gives insignificant effec

قياس تركيز باعثات الفا في الادرار البشري باستخدام كاشف الاثر النووي في الحالة الصلبة PM - 355 == Determination of alpha emitters concentration in human

Author name: شيماء ذياب عطية العبودي
Supervisor name: مازن مانؤيل الياس | ندى فاضل توفيق
General topic: Physics
Specific topic: Nuclear and Environmental Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: This work owes its importance to the fact that it aims at knowing and measuring the concentrations of alpha - particles emitters discrete by the human body in the urine in particular. Knowledge of these concentrations is extremely important since it reveals whether a person has received such doses of radioactive materials emitting alpha - particles that result in the occurrence of malignant tumor and mutations. This subject being so essential to the health of individuals and being a great help to physicians to make the proper diagnosis in the relevant cases, has imposed itself on us as the topic of this thesis. Human urine samples were taken from Iraqi workers in different fields (phosphate plants, fertilizer plants, teaching staff in nuclear physics laboratory, painters, patient and reference healthy people of different ages), using PM - 355 solid state nuclear track detectors. The exposure method was used by immersing PM - 355 detectors in urine samples for three weeks, then etching by 6.25N NaOH for 5 hrs. The track density was measured via an optical microscope. The alpha emitters concentrations in the urine samples were calculated in comparison with standard samples that were prepared in the nuclear laboratory of physics department - College of Science AL - Nahrain University.The obtained results show that the concentrations of alpha emitters in the urine samples of patients range from 1.81ppm to 2.87ppm , from 0.087ppm to 1.32ppm in reference healthy people, in painters from 0.77ppm to 1.46ppm,workers in phosphate plants from 0.94 ppm to 1.89 ppm, workers in fertilizer plants from 1.0ppm to1.42 ppm , and from 1.0 ppm to 1.29 ppm in teaching staff in nuclear physics laboratory .Deductions from the results of this work regarding the dependence of concentrations on the person's occupation, years of service, sex, age and health condition have been dealt with in sufficient details as required.

اثر التلدين على الخواص البصرية لاغشية اوكسيد الالمنيوم (Al2O3) الرقيقة المحضرة بطريقة الترسيب الكيميائي الحراري == The effect of annealing on the optical properties of (Al2O3) thin films prepared by chemical spray pyrolysis

Author name: عبير كمال جعفر
Supervisor name: خضير عباس مشجل | ابتسام محي عبد العزيز
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: The recent study deal with the structural and optical properties of Al2O3 thin films prepared by the chemical spray pyrolysis technique at glass substrate(450°C) and studying the effect of annealing at different temperatures (500,550,600) °C on the optical properties.The results of X - ray diffraction showed that the prepared films are polycrystalline, the study of optical properties included the record of transmittance spectrum of the films with the wavelengths range from (300 - 900)nm, and then measuring the forbidden energy gap of electronic transitions where it was found that the values of the forbidden energy gap of both allowed and forbidden transitions are (3.4)eV and (2.5)eV successively and it was (1.6)eV for the allowed indirect transition. When annealing the Al2O3 thin films, the values of the forbidden energy gap of the allowed and forbidden of direct transitions are (2.7)eV and (3.6)eV and it is (1.9)eV for the allowed indirect transition. Also, absorption coefficient , reflectance and optical constants such as extinction coefficient, refractive index, dielectric constants with it's two parts real and imaginary and optical conductivity as a function of photon energy have been studied, the study showed that the annealing caused an increase in energy gap values, reflectance, transmittance, refractive index and real part of dielectric constant, and a decrease in the values of absorptance, absorption coefficient, extinction coefficient, imaginary part of dielectric constant and the optical conductivity.

نموذج بطارية باستخدام برامجيات PSPICE مع مغير شحن ثنائي الاتجاه == Pspice Battery Model with Bidirectional Charging Converter

Author name: زينة موفق قدوري حسين العزاوي
Supervisor name: زينب منذر يونس كبة
General topic: Physics
Specific topic: Physics
Degree: Master
University: Al-Nahrain University - College Of Science - Physics Department
Language: English
University location: Baghdad
First pages:
Abstract: This research intents to design Bidirectional Converter that can be used in wide applications from uninterrupted power supplies (UPS), photovoltaic (PV) and battery charging and discharging system, to auxiliary power supplies designed primarily with a general module depending on Orcad PSPICE program.Lead Acid battery model (12V) is putted, which is used in wide applications. The model consists of charge efficiency and battery voltage components. The charge efficiency factor can vary from (0 to 1) and is dependent on the Battery State of charge and charge current. The voltage component of the model consists of amp - hour integrator which tracks the net current flowing into the battery terminal (Battery voltage). The output of the integrator gives us the state of charge so, it is connected to a table driven voltage source, ETABLE, which generates the equivalent open circuit battery voltage. The method used here is implemented in orcad PSPICE program with bidirectional converter of properties (D=0.4, P=12W, Vo=12V, f=1 KHz, Io=1A).
1 ... 21 22 23 24 25 ... 38