A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave number (1 & 0.75) for Rayleigh number of (1000).
Background: Beta thalassemia is a typically autosomal recessive form of severe anemia which is caused by an imbalance of two types of protein (alpha and beta) subunits of hemoglobin. Oxidative stress imbalance is the equilibrium between pro-oxidant\antioxidant statuses in cellular system, which results in damaging the cells. Antioxidant is a chemical that delays the start or slows the rate of lipid oxidation reaction and it play a very important role in the body defense system against reactive oxygen species. The aims of this study were to recorded the oro-facial manifestations in beta thalassemic patients and assess the oxidative stress marker malondialdehyde in serum and salivs and their role in the pathogenesis of beta thalassemia and ev
... Show MoreBreast cancer (BC) is one of the most frequently observed malignancy in females worldwide. Today, tamoxifen (TAM) is considered as the highly effective therapy for treatment of breast tumors. Oxidative stress has implicated strongly in the pathophysiology of malignancies. This study aimed to investigate the changes in the levels of oxidants and antioxidants in patients with newly diagnosed and TAM-treated BC. Sixty newly diagnosed and 60 TAM-treated women with BC and 50 healthy volunteers were included in this study. Parameters including total oxidant capacity (TOC), total antioxidant capacity (TAC), and catalase (CAT) activity were determined before and after treatment with TAM. The serum levels of TOC and oxidative stress index (OSI) were
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Gastrointestinal diseases and especially chronic gastritis are mainly induced by Helicobacter pylori infection, and provides the basis for gastric carcinogenesis and colorectal cancer. The study involved the detection of serum anti-H. pylori IgG and IgA antibody of and some serum biomarkers ;CEA and CA19-9 in patients with gastrointestinal diseases. Fifty eight serum samples were collected from 25 males and 33 females .Peripheral venous blood was collected from each patient and sera obtained by centrifugation. Serum anti-H. pylori IgG and IgA ,serum CEA and CA19-9 were evaluated by enzyme-linked immunoadsorbent assays (ELISA).Forty eight serum samples were positive for IgG (82.7% ) divided int
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Hydro cracking of heavy oil is used in refinery to produce invaluable products. In this research, a model of hydro cracking reactor has been used to study the behavior of heavy oil in hydro cracking under the conditions recommended by literature in terms lumping of feed and products. The lumping scheme is based on five lumps include: heavy oil, vacuum oil, distillates, naphtha and gases. The first order kinetics was assumed for the conversion in the model and the system is modeled as an isothermal tubular reactor. MATLAB 6.1 was used to solve the model for a five lump scheme for different values of feed velocity, and temperature.
يهدف هذا البحث إلي معرفة معنى اللغة وتجلياتها في نتاجات الاديب الإسرائيلي الأكثر جدلا في القرن العشرين، إلا وهو الاديب "موشيه سيملانسكي". فقد طغت صورة العربي في الكثير من أعماله الأدبية وتبوات مكانا واضحا، وكانت النظرة تجاهه، نظرة واضحة أيضا، فصورته لم تتغير بتغير الظروف والاتفاقيات، بشكل يتناسب وهذه الظروف، وإنما بقيت تراوح مكانها، ولم تتبدل بنظرة احترام على الأقل، بل على العكس من ذلك، فهناك بعض المطالبات
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منذ بداية نشوء المستشفيات كمنظمات تعنى بصحة الناس، عُرف الصراع (Conflict) بين جماعتي الإدارة والأطباء. وقد تركز محوره في معظم الأحيان حول سلطة أي منهما هي الأقوى في اتخاذ قرارات المستشفى.. هذا إذا ما علمنا أن كل من الطرفين المتعارضين يستمد قوته ويعزز مكانته من خلال سلطته في اتخاذ القرارات. إن جهود كلا الجماعتين الطبية والإدارية تصب في منهل واحد ألا وهو خدمة المريض والارتقاء بالمستوى الصحي ل
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أهمية الدراسة والحاجة اليها:
يعد النشاط المدرسي للمعلم والطالب جهدا عقلياً وبدنياً يبذله المعلم والطالب بمساعدة المدرسة لتحقيق اهداف مرسومة وهو ممارسة تظهر في اداء الطلبة على المستوى الحركي والفعلي والنفسي والاجتماعي بفعالية داخل المدرسة وخارجها. (اللقاني،بلا، ص82).
ان الانشطة والبرامج المدرسية التي تنظم داخل الصف
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