فى هذه الدراسة تم تحديد خواص دالة هاملتون بإستخدام نمودج المفاعلة البوزونية IBM-2 وإيجاد أفضل البارامترات لدالة هاملتون وحساب قيم مستويات الطاقة وإحتمالية الإنتقال للنظائر Hg200-194، Kr90-84 ومقارنتها بالنتائج التجريبية والمحسوبة بطرق نظرية أخرى. Abstract In this study, we have determined the most appropriate Hamiltonian using the interacting boson model (IBM-2), and obtained the best fitting values of parameters to construct the Hamiltonian. We also have calculated the energy levels and the transition probabilities for Kr84-90and Hg194-200 and have compared the calculated values with experimental data and with the results of other calculations.
نجاة سالم الشفتري (2010)

Abstract Laser surface treatment of materials is one of the most effective methods of improving properties and performance of metallic articles. This technique proved its capabilities and advantages in comparison with other methods of surface treatment As an example, it has been shown that the distortion caused by this type of treament is at least one order of magnitude smaller than by that due to other techniques. Moreeover, laser beam is capable of reaching practically any point of the surface whatever it is narrow or difficult to reach by other techniques. The current work investigates the possibility of improving certain mechanical properties of both technically pure aluminum and A1-4o/oSi alloy, using ruby laser of 3 xl 05 W/cm2 power density. The surface of the investigated materials has been impregnated by SiC particles of varying size ranges, with or without firrther alloying of the surface with Titanium powder addition to the impregnated mixture. The laser treatment included coating one surface of each specimen of SiC particles by means of a binder added at a certain ratio (with or without Ti additions to the mixture). The coated surface was then subjected to the laser beam, which melted a layer I OO-150Jilll thick. Due to hydrodynamic effects the melt mixes with SiC particles and dissolves some or all of the added Ti and rapidly solidifies forming a thin layer distinct in properties from the original surface. Two groups of specimens were used in this study. The first group was treated by impregnating SiC particles of one size range with or without Ti-additions. Various numbers of laser pulses have been applied increasmg in a geometrical progression (1-2-4-8 pulses). These specimens were used for the study of the effect of varying: 1) the chemical composition of the substrate materials ;2) the number of laser pulses :and 3) the effect of Ti additions to the impregnating mixture on the microstracture and microhardness of the treated zones. The specimens of the 2nd group were coated by a square network of laser treated zones each 1.5mm in diameter. These specimens have been used to study :1) the effect of the chemical composition of the substrate material ;2) the size of the SiC particles and 3) the effect of Ti addition to the mixture on the wear perfomance of the treated specimens. Identical specimens have been used to determine the solubility of Si into the aluminum phase during the test by means of x-ray diffraction. This dissolved Si is partly responsible for the increase ID microhardness and wear resistance of the investigated specimens. The results show the positive effect of the applied treatment on the properties and preformence of technically pure AI and A-4%Si alloy. The materials microhardness within the treated zones has been increased by a factor of 2.7 and 2.4 for pure Al and Al-4%Si substrates, respectively. The microstructure of the treated zones became more homogeneous and the penetration of SiC particles into them has been increased with increasing the number of the applied laser pulses. The wear resistance of pure Al has been increased by a factor of 73.6 due to laser assisted impregnation, while that of AI-4%Si by afactor of 42.5. Wear resistance was found to increase with I) Si addition to the base metal; 2) Ti addition to the impregnated mixture, and 3) increasing the SiC particle size. This thesis is a part of a wider study that deals with surface treatment of Al and AI-Si alloys undertaken in our laboratry. Such study proved how effective the laser alloying and impregnation of such alloys in improving some of their mechanical properties which are important in industrial application, especially in internal combustion engine design.
أسماء عبد الرزاق وهرة (2002)

يستخدم الجادولنيوم كعامل لتحسين تباين صور الرنين المغناطيسي في أغلب حالات التصوير التي يتعذر فيها تحديد نوع الاصابة او طبيعة الورم، ويتميز الجادولنيوم بخصائص مغناطيسية تمكنهُ من التأثير على زمن الاسترخاء للبروتونات الموجودة في النسيج. مما يسبب في زيادة شدة الاشارة أو تقليلها حسب نوع الصورة. ويهدف هذا البحث لدراسة العلاقة بين زيادة شدة الإشارة في أنسجة الدماغ بعد استخدام الجادولنيوم وبعض البارامترات المحسوبة إحصائيا عن طريق معالجة صور الرنين باستخدام طريقة مصفوفة التكرارات للمستويات الرماديةGrey Level Co-occurrence Matrix. وحيث أن زيادة شدة الاشارة تكون نتيجة تقصير زمن الاسترخاء في الصورة المرجحة T1. تم دراسة إحدى أهم العوامل المؤثرة في الإشارات المكونة لصورة الرنين المغناطيسي وهو زمن الاسترخاء، وتم توضيح تأثير زمن الاسترخاء الطولي T1 والعرضي T2على تباين انسجة الدماغ في صور الرنين، ثم قمنا بمعالجة صور مرجحة لزمن الاسترخاء الطولي (T1- Weighted) أُخدت في المقطع المحوري (axial)، هذه الصور لحالات مصابة بأورام في الدماغ تم فيها استعمال الجادولنيوم. اهتمت هذه الدراسة بتحديد العلاقة بين زيادة شدة الاشارة في الانسجة المصابة وبعض البارامترات المحسوبة احصائياً عن طريق المعالجة. كما تم دراسة مدى استجابة الانسجة الطبيعية للجادولنيوم وتم مقارنتها بالأنسجة المصابة. واثبتت النتائج ان زيادة شدة الإشارة بعد استعمال حُقن الجادولنيوم في المناطق التي تحتوي على أنسجة مصابة يزيد في قيم البكسل المكونة لصورة الرنين. وبينت النتائج أن زيادة شدة الإشارة تتناسب مع تلك البارامترات المحسوبة كُلا حسب طبيعة النسيج. Abstract Gadolinium used as a factor to improve the contrast magnetic resonance images, in most cases of imaging that can't determine the type of lesion or tumor. Gadolinium is characterized by magnetic properties of being able to influence the relaxation time of protons in tissue. This would cause an increase or decrease in the intensity of the signal depending on the type of image. This research aims to study the relationship between the increases in signal intensity in the brain tissue by using Gadolinium. Statistically method would be implied after resonance images are processed, using a matrix method of iterations for gray level, it is know as Grey Level Co-occurrence Matrix. In T1-weighted image, an increase in signal intensity is duo to shorting of relaxation time. Relaxation time which is considered as one of the most important aspect effecting the signal component from MRI images was studied in depth. Also, the effect of relaxation time longitudinal T1 and transverse T2 on the variation of brain tissue were clarified. Then, T1-weighted axial images were processed. Images used in this work were taken from patients with brain tumor, and contrast agent (Gadolinium) was used to enhance them. This study focused on identifying the relationship between the increase in signal intensity in the lesion tissues and statistically calculated parameters. The respond of normal and effected tissues the Gadolinium were compared. The study shows that an in increases in pixel intensity, after contrast is introduced, in areas with infected tissue. Also, the results indicate that signal intensity commensurate with those calculated parameters.
تهاني عياد صالح العباني (2014)