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).
بلا شك ان عملية اختيار القرار الصائب للموظف من مجموعة التفضيلات المقدمة له، ستحقق بالتأكيد لديه الشعور بالرضا، وكما ستدفعه الى المزيد من اتخاذ القرارات نحو الخيارات من دون تردد او شك مما ستخلق في نفسه الثقة والرضا الذاتي والايجابية في التفكير . ونلاحظ بان اغلب موظفي الدولة يمارسون وظائف لا تبعث في نفوسهم الرضا سواء كانت تلك الوظائف تعود الى القطاعات الحكومية او القطاعات الخاصة، وذلك لأنهم قد اجبروا على ممارس
... Show Moreيُسلط البحث الضوء على الدور الجيواستراتيجي للمرأة في مجالي الإغاثة والتنمية ضمن نظام الحوكمة الصحية الدولية، متخذاً من منظمة الصحة العالمية (WHO) أنموذجاً تحليلياً لتقييم فاعلية العمل الإنساني. تنطلق الدراسة من إشكالية "المفارقة الهيكلية"؛ ففي حين تُشكل المرأة (70%) من القوى العاملة وتمثل فاعلاً محورياً وعنصراً حاسماً لامتصاص الصدمات ومنع تفكك النظم المجتمعية في بؤر الأزمات المعقدة (كما أثبتت النماذج في غزة، ا
... Show Moreتولي المجتمعات المتقدمة اجتماعياً واقتصاديا وثقافيا وعلميا اهتماما بارزا للعنصر البشري واستثماره على أفضل صورة ممكنة لتحقيق التقدم والرفاهية لتلك المجتمعات وللأفراد على حد سواء , وتحتل تنمية الثروة العقلية واستثمارها محل الصدارة حيث يبذل اهتمام خاص للكشف عن المواهب والكفاءات المبدعة وتنميتها وتوجيهها ورعايتها علميا وتربويا ومهنيا وذلك لان العنصر البشري يعد جزءا لا يتجزأ من الثروة القومية للأمة حيث
... Show MoreThe problem of the research is that some companies lack the mechanisms and policies that to enhance the loyalty of these valuable resources, which led to difficulties in generating knowledge, producing, storing, investing and investing information to achieve a sustainable competitive advantage. In addition, companies are still working with the traditional wage system (monthly salaries), which makes people not think about adding value to work. The research aims to determine the level of variables for researchers to clarify the impact of the organizational innovation climate on sustainable competitive advantage. The Qualitative approach is used based on research. The research was applied
... Show MoreThis paper deals with the most important issue in sustainable demelpment in Arabic Islamic economic ideology.
It discusses the concept of zakat & its developments.It give ahistorical view on Zakat depanding or Holy Quran we identify that zakat depanding or Holy Quran. We identify that Zakat must be: gold, silver &its position inits indgment suchas cashpaper
Israel is one of the countries most interested in Iran's nuclear program file, and the progress of negotiations between Iran and the six countries and will end it, as well as the nature of the relationship between Iran and the United States of America. Is determined by the Israeli vision of the nature of Iran's nuclear program Iran's policy toward Israel orientations, which does not recognize the existence of Israel. Israel, therefore, one of the countries pushing to prevent Iran from acquiring nuclear technology. However, those Israeli efforts did not succeed in achieving its objectives, the United States of America and European countries is well aware of the risk of stenosis on Iran, as well as the risks and the consequences of militar
... Show Moreتناول المقال موضوع استثمار الذكاء الاصطناعي في تحليل البيانات الضخمة داخل المؤسسات العلمية، وركز على توضيح أهمية هذا التكامل في تعزيز الأداء الأكاديمي والبحثي. استعرضت المقالة تعريفات كل من الذكاء الاصطناعي والبيانات الضخمة، وأنواع البيانات داخل المؤسسات العلمية، ثم بينت أبرز التطبيقات العملية مثل التنبؤ بأداء الطلبة، والإرشاد الذكي، وتحليل سلوك المستخدمين، والفهرسة التلقائية. كما ناقشت المقالة التحدي
... Show MoreThis study deals with it the era of Taher Bin Al Hussein for his son Abdullah when preside Diyarbakir and Rabia in succession of ALMa`amoon Abbasi in the political and historical dimensions
In the past, an absolute authority was held by the father and his decisions were imposed
and obeyed strictly without discussion. Later, many economical changes took place and
affected all of the family members dramatically creating a whole new concept of authority
in the family, a one that is based upon sound leadership, mutual understanding and
consultation among family members.
Women carried responsibility of doing all domestic jobs and served family members,
however, when she went to work outside her house, these loads began disturbing and
exhausting her. Therefore, man started to participate in assisting his wife. In addition,
industrial advances contributed in making these jobs easier than before.
This has