Abstract In this work, study was performed using Amorphous polymer – based composites consisting of polystyrene (PS) and carbon black (CB) . Five samples have been prepared with different weight percentage which are (0%CB+100%PS) , (5%CB+95%PS) , (15%CB+85%PS) , (25%CB+75%PS) and (35%CB+65%PS) . The electrical properties have been studied for these samples as follows : Electrical conductivity , relative dielectric constant and the dielectric loss tangent were measured at alternating electric field in temperature range between (30C°) and (60C°) and at four different constant frequencies (100HZ, 1KHZ, 10KHZ and 100KHZ ) . It is noted that the highest value of alternating electrical conductivity at (30C°) is for the sample of composition (25%CB+75%PS) which was (1.25x10 S/m ) and the highest value at temperature (60C°) was for same sample with value of (3.2x10 S/m ) , it should be noted that in general the electrical conductivity increases as the temperature increases where this result shows the behaviour of semiconductors. The relative dielectric constant in the pure sample (0%CB+100%PS) and the other samples with low percentage of carbon black increases as the temperature increases however it decreases as frequency increases. And the samples with higher percentage of carbon black which are (25%CB+75%PS) and (35%CB+65%PS) it was noted that the relative dielectric constant decreases as temperature increases. The lowest value was (1.26) at temperature (30C°) and frequency (10KHZ) for the sample with composition of (15%CB+85%PS), while the highest value at same temperature is (410.2) at (100HZ) for the sample with composition of (25%CB+75%PS), for the relative dielectric constant the highest result it was for the sample (5%CB+95%PS) at (607) at (100HZ) and (45C°). The dielectric loss tangent increases as the carbon black increases in all samples and it was found that the temperature influence will be at high percentage of the carbon black where the temperature of (55C°) the dielectric loss tangent increased to the highest value (1.2X10 ) for the sample of composition (35%CB+65%PS). at the high level of the carbon black it was found that the dielectric loss tangent decreases as the frequency increases.
عادل محمد التميمي (2013)

In this study, we have determind the most appropriate Hamiltonian for the study of even-even Cd 114-120 to calculate, its energy levels using the interacting boson model IBM1. In addition, the backbending (moment of inertia as a function of (hw) of the energy levels for each isotope was indicated through the experimental and calculated values of the energy levels. A simulation program with MATLAP-18 has been built for this purpose, the results were compared with previous experimental data and it was observed that they were on a good agreement.
Dalenda M. Nasef , Suad M. Bograin, Najat Eshaftri , Ayad Ezwam , Sadek Elkadi (10-2021)

في هذا العمل قمنا بدراسة منظومة عناصر المجموعة الثانية (Be, Mg, Ca, Sr, Ba) باستخدام نظرية دالة الدالة للكثافة (DFT)، حيث تعتبر (DFT)من أهم النظريات التي ظهرت خلال العقود القليلة الماضية, وأثبتت نجاحها في اغلب الانظمة الفيزيائية. لقد أثبتت هذه النظرية أن خواص النظام الفيزيائية في حالته الأرضية دالة وحيدة فقط في كثافته الإلكترونية، وفي مقدمتها الخواص الكهربية، كما أن لعناصر المجموعة الثانية أهمية كبيرة في مجال العلوم والتكنولوجيا وتطبيقات عديدة في الصناعات الإستراتيجية المختلفة، وعليه فقد كانت مجال هده الدراسة. إن هدفين تم تحقيقهما في هده الدراسة: اختبار لنظرية دالة الدالة للكثافة (DFT) في الأنظمة المعقدة نسبيا، ودراسة عناصر المجموعة الثانية لأهميتها الصناعية والتقنية. تم تصميم نموذج نظري للكثافة الإلكترونية للعناصر المعدنية في الحالة المفردة (معدن واحد) والمزدوجة (الثنائيات المعدنية) سواء كانت متشابهة أو مختلفة، هذا النموذج في صورة دالة رياضية تصف ما يحدث للكثافة الإلكترونية وبالتالي الشحنة الكهربية الكلية في كل الفضاء الذي يشغله النظام استناداً إلى نموذج جيليوم. لقد حقق هذا النموذج كل الشروط اللازمة للتعبير عن النظام بما في ذلك الحدودية منها ويتوافق مع ما يحدث للأسطح البينية المعدنية بسبب التشابه أو الاختلاف وكذلك المسافة الفاصلة بينهما (2d)، واستجاب أيضا للعمليات التحليلية والحسابية العددية, بكفاءة عالية فقد تم حساب الكثافة الإلكترونية كدالة في المسافة العموديةعلى المستوياتفقط بسبب تماثل الشحنة الكهربية فيها, بالإضافة إلى ذلك فقد تم التوصل إلى صيغ للمجال الكهربي و الجهد الكهربي وكذلك طاقة النظام الكلية وبالتالي إلى حسابها.أظهرت نتائج هذه الحسابات دقة هذا النموذج وقدرته على التكيف مع ظروف النظام، وتميزه عن غيره من النماذج بأنه يعتمد على متغير واحد فقط وهو نصف قطر الحيز الذي يشغله الإلكترون في كل عنصر (rs) و كذلك صلاحيته لكل العناصر المعدنية بغض النظر عن المجموعة التي تنتمي لها. وبصفة عامة كانت نتائج حسابات الكثافة الالكترونية، كثافة الشحنة الكهربية، المجال الكهربي والجهد الكهربي متفقه مع الدراسات السابقة كمياً في حدود بينما كانت أكثر دقة من حيث الكيف، بإظهارها لتذبذبات فريدل والتسرب الميكانيكي الكمي للإلكترونات بوضوح، عليه أثبتت هذه الدراسة نجاح نظرية (DFT) بقوة في مثل هذه الأنظمة وأكدت أهمية استخدام عناصر المجموعة الثانية في مجالات العلوم والتكنولوجيا. Abstract In this work, we have studied Group IIA elements (Be, Mg, Ca, Sr, Ba) by using Density Functional Theory (DFT). DFT is the most important theories appeared during the near past decades, this theory proved clearly that the physical properties of the system in its ground state are a unique function of its electronic density, such as electric properties. The second group elements are of great importance in science and technology fields, it has many applications in various strategic industries, so it was the field of this study. Two goals have been defined for research in this study, first goal is to test DFT in these relative complex systems, and the second, is to provide important information on Group IIA elements, for its applications in science, industry and technology.Theoretical model of the electronic density has been designed of the metallic elements in a single case (One metal) and double case (Bimetallic), whether similar or different interfaces, mathematically this model is a function depends on some parameters, describing the electronic density for the whole space occupied and surrounding by the system and hence the total charge density based on the Julliem strategy. This model satisfied all necessary conditions and described the system perfectly, including, boundary conditions, and the electronic density profiles for both similar and different inter-metal surfaces and its interspacing (2d). It responded analytically, as well as numerically, to the computational processes with high efficiency. The electronic density for all suggested systems was calculated as a function of distance (z) only due to charge symmetry in (xy) planes. In additional to that, the electric field, electrostatic potential and the total energy formulas has been derived and calculated. Our results showed a high degree of accuracy and ability of this model, also its adaptation to the different conditions of the system. This model was distinguished from any other previous models by its dependency on only one variable, which defined for each element (rs), and its suitability for all metallic elements regardless of the group to which they belong. In general the results of the calculations of electronic and charge density, electric field and electric potential are agreed with previous studies quantitatively within while it was higher accuracy qualitatively; by showing clearly Friedl oscillations and the quantum mechanical leakage of electrons .However, this study strongly proves the success of DFT in such systems and confirmed the importance use of the second group elements in the science and technology fields.
أمنية موسى أحمد عليان (2009)