The structural properties of ternary chalcopyrite AgAlSe2 compound alloys and thin films that prepared by the thermal evaporation method at room temperature on glass substrate with a deposition rate (5±0.1) nm s-1 for different values of thickness (250,500 and 750±20) nm, have been studied, using X-ray diffraction technology. As well as, the optical properties of the prepared films have been investigated. The structural investigated shows that the alloy has polycrystalline structure of tetragonal type with preferential orientation (112), while the films have amorphous structure. Optical measurement shows that AgAlSe2 films have high absorption in the range of wavelength (350-700 nm). The optical energy gap for allowed direct transition we

Tin dioxide doped silver oxide thin films with different x content (0, 0.03, 0.05, 0.07) have been prepared by pulse laser deposition technique (PLD) at room temperatures (RT). The effect of doping concentration on the structural and electrical properties of the films were studied. Atomic Force Measurement (AFM) measurements found that the average value of grain size for all films at RT decrease with increasing of AgO content. While an average roughness values increase with increasing x content. The electrical properties of these films were studied with different x content. The D.C conductivity for all films increases with increasing x content. Also, it found that activation energies decrease with increasing of AgO content for all films.

A thin film of AgInSe2 and Ag1-xCuxInSe2 as well as n-Ag1-xCuxInSe2 /p-Si heterojunction with different Cu ratios (0, 0.1, 0.2) has been successfully fabricated by thermal evaporation method as absorbent layer with thickness about 700 nm and ZnTe as window layer with thickness about 100 nm. We made a multi-layer of p-ZnTe/n-AgCuInSe2/p-Si structures, In the present work, the conversion efficiency (η) increased when added the Cu and when used p-ZnTe as a window layer (WL) the bandgap energy of the direct transition decreases from 1.75 eV (Cu=0.0) to 1.48 eV (Cu=0.2 nm) and the bandgap energy for ZnTe=2.35 eV. The measurements of the electrical properties for prepared films showed that the D.C electrical conductivity (σd.c) increase

Indexing manuscripts is one of the important technical operations carried out by the indexer because of the descriptive or bibliographic data it provides

    Indexing manuscripts is one of the important technical operations carried out by the indexer because of the descriptive or bibliographic data it provides.

عاش البيروني في القرن الرابع الهجري الذي كان يمثل مثاراً للصراعات السياسية والفكرية، ومن خلال هذه الأوضاع المتأزمة برز البيروني كعلم من اعلام هذا القرن، ومن أبرز مفكري الحضارة العربية الاسلامية فنجده كتب في الرياضيات

مشكلة البحث والحاجة إليه.

     من المشاكل الشائعة والمألوفة بين طلبتنا هي قلق الامتحان، ذلك القلق الذي يبقى طبيعيا مادام في مستواه الطبيعي وهو يختلف من طالب الى آخر في صور ظهوره المختلفة فقد يبدو واضح الأعراض لدى بعض الطلبة؛ فقد يؤثر على تذكرهم للمادة العلمية أو الإجابة على بعض الأسئلة أو يؤثر على تركيزهم وتشتت انتباههم وتفكيرهم والتوتر وسرعة الانفعال. (11: بلا)

وكل

A thin film of SnSe were deposited by thermal evaporation technique on 400 ±20 nm thick glass substrates of these films were annealed at different temperatures (100,150,200 ⁰C), The effect of annealing on the characteristics of the nano crystalline SnSe thin films was investigated using XRD, UV-VIS absorption spectroscopy, Atomic Force Microscope (AFM), and Hall effect measurements. The results of X-ray displayed that all the thin films have polycrystalline and orthorhombic structure in nature, while UV-VIS study showed that the SnSe has direct band gap of nano crystalline and it is changed from 60.12 to 94.70 nm with increasing annealing temperature. Hall effect measurements showed that all the films have a positive Hall coeffic