A random laser is a non-conventional laser whose feedback mechanism is based on dissorder-induced light. However, random lasers occur in gain media with numerous scatterers and produce coherent laser emission without any predesigned cavity. The generation of coherent emission from multiple scattering is quite general and its basic principles are shown here using sulforhodamine B-TiO suspensions system. These suspensions were pumped with 337.1 nm pulses from N2 laser and the spectral and temporal behavior of light emitted from the pumped surface was recorded. When we pump power above a certain threshold a dramatic narrowing of the emission line width and a shortening of the emitted pulses were observed. We have experimentally found that in a random laser based scattering, the threshold pumping density decreases with pump energy increased.
تعد ظاهرة الارهاب المتزايدة في العالم من اخطر اشكال التهديدات الامنية التي تواجة الدول لانها تستهدف في جانب مهم منها امن واستقرارومستقبل مجتمعاتها لاسيما اذا جمع الفعل الارهابي بين مطامع واهداف القوى الخارجية التي لا تريد استخدام ادواتها المباشرة وانما بالاعتماد على محركات في خلق الازمات داخل الدول المستهدفة
... Show More
Sn effect on the phase transformation behavior, microstructure, and micro hardness of equiatomic Ni-Ti shape memory alloy was studied. NiTi and NiTiSn alloys were produced using vacuum induction melting process with alloys composition (50% at. Ni, 50% at.Ti) and (Ni 48% at., Ti 50% at., Sn 2% at.). The characteristics of both alloys were investigated by utilizing Differential Scanning Calorimetry, X- ray Diffraction Analysis, Scanning Electron Microscope, optical microscope and vicker's micro hardness test. The results showed that adding Sn element leads to decrease the phase transformation temperatures evidently. Both alloy samples contain NiTi matrix phase and Ti2Ni secondary phase, but the Ti2Ni phase content dec
... Show More
(2)
(1)
Liquid electrodes of domperidone maleate (DOMP) imprinted polymer were synthesis based on precipitation polymerization mechanism. The molecularly imprinted (MIP) and non-imprinted (NIP) polymers were synthesized using DOMP as a template. By methyl methacrylate (MMA) as monomer, N,Nmethylenebisacrylamide (NMAA) and ethylene glycol dimethacrylate (EGDMA) as cross-linkers and benzoyl peroxide (BP) as an initiator. The molecularly imprinted membranes were synthesis using acetophenone (APH), di-butyl sabacate (DBS), Di octylphthalate (DOPH) and triolyl phosphate (TP)as plasticizers in PVC matrix. The slopes and limit of detection of l
... Show MoreAddition of bioactive materials such as Titanium oxide (TiO2), and incorporation of bio inert ceramic such as alumina (Al2O3), into polyetheretherketone (PEEK) has been adopted as an effective approach to improve bone-implant interfaces. In this paper, hot pressing technique has been adopted as a production method. This technique gave a homogenous distribution of the additive materials in the proposed composite biomaterial. Different compositions and compounding temperatures have been applied to all samples. Mechanical properties and animal model have been studied in all different production conditions. The results of these new TiO2/Al2O3/PEEK biocomposites with different
... Show More
(1)
الملخص: تعد عناصر اللياقة البدنية العمود الفقري للألعاب الرياضية وخصوصا في الالعاب الجماعية ومنها لعبة كرة القدم للصالات والتي تعد من الالعاب الرياضية التي تتطلب بذل جهود كبيرة خلال المنافسة نظرا لطبيعة الاداء الذي يمتاز بالقوة والسرعة طيلة شوطي المباراة وهذا يتطلب من اللاعب امتلاكه للياقة بدنية عالية تؤهله للإيفاء بهذه المتطلبات خلال المنافسة، لذا نجد المدربين يتبعون كافة الاساليب وطرائق التدريب في سب
... Show More
تضمن البحث تحقيق مخطوط"، سرور الفؤاد بالصافنات الجياد في معرفة الخيل
وأسمائياالشيخ محمد العمري" وكما ظاىر من عنوان المخطوط إنوُ يتناول الخيل، والخيل
موضوع ميم في حياة العربي قبل الاسلام باعتباره يمثل جزءاً من تفاصيل حياتو الملازمة لوُ
واعتماده عمييا ىذا أولاً وثانياً ماتحمموُ الخيول من معاني الفروسية والعنفوان وماتثيره في
الأنسان من حب الأقتناع والمتعة المتحققة من النظر إلييا وحبو لمسبق،