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).
The research aims to determine the mix of production optimization in the case of several conflicting objectives to be achieved at the same time, therefore, discussions dealt with the concept of programming goals and entrances to be resolved and dealt with the general formula for the programming model the goals and finally determine the mix of production optimization using a programming model targets to the default case.
The object of this study is to establish a global model to use of DeNovo programming the strategies of multi-Decision making process in the city of Baghdad.
Thus, we have chosen an important and an effective subject in the life of the citizen due to the importance of this subject in the Iraqi citizen of luck of water and for many reasons.
In this thesis, we have tackled the establishment of a global model to be able to reach solution or an alternative model a money the available alternative.
The alternative proposed here utilizes the application of the (DeNovo) programming approach suggested by (1982) in solving t
... Show More
An optical video communication system is designed and constructed using pulse frequency modulation (PFM) technique. In this work PFM pulses are generated at the transmitter using voltage control oscillator (VCO) of width 50 ns for each pulse. Double frequency, equal width and narrow pulses are produced in the receiver be for demodulation. The use of the frequency doubling technique in such a system results in a narrow transmission bandwidth (25 ns) and high receiver sensitivity.
The present research deals with studying the formal variations for the Quranic calligraphy at the beginning of Islam , as being regarded from the original Arabic calligraphies which were developed later till they became as they are now, where the calligraphers in pushing for simulating these original calligraphies and knowing the methods of their writing by the calligraphers at that time.That helped in enriching and developing the aesthetic and designing valuesFor these calligraphies, as being calligraphic achievements represent transmission resulted from the objective, aesthetic and indicative vision in producing the verses according to a certain form. This has a clear impact in tendency to the technical, aesthetic and expressing develo
... Show More
يعد موضوع الثورات العربية من الموضوعات التي تحظى بأهمية كبيرة على المستويين الاقليمي والدولي، لذا فقد طورت مؤسسات الابحاث الدولية ومراكز صنع القرار السياسي والاستراتيجي الاطر والمفاهيم الجديدة في مجال السياسة الدولية، نظرا للتطورات التي شهدتها المنطقة العربية والتي استدعت التطرق الى مجموعة من المفاهيم النظرية ذات العلاقة الوثيقة بما هو حاصل في المنطقة العربية من تغييرات مما تطلب الامر البحث والتدقيق ومن
... Show Moreأصبحت التنشئة الاجتماعية السليمة من أكثر الأدوات في التصدي لأوبئـة العنف والتطرف ومظاهرها المتفشية بصورة أو بأخرى في مجتمعاتنـا المعاصـرة عامـة باختلاف أيديولوجياته الفكرية ومعتقداته الدينيـة ومسـتوى نموهـا الاقتصـادي، وأصبحت بأشكالها المتنوعة معنية بترسيخ التعاليم الدينيـة السـمحة وغـرس القـيم الديمقراطية السليمة ومبادئ وقيم حقوق الإنسان في شتى مجالات الحياة الإنسانية، وهي أيضا تعد حجر الأساس من اج
... Show MoreThe calamities, calamities, problems and constant dilemmas that society is experiencing have made it the responsibility of professors and researchers to find appropriate and effective solutions to these issues, and among those calamities that our societies faced was the problem of the epidemic represented by (Corona-Covid-19),
الحمد لله رب العالمين، والصلاة والسلام على سيد المرسلين، محمد وعلى آله وصحبه أجمعين وبعد:
فإن الله تعالى خلقنا أزواجا، وجعل منا الذكر والأنثى يميل بعضهم إلى بعض بالفطرة والطبع ليكونا بمشيئة الله أسرة، ويرزقان بنين وحفدة، وهذه سنة الله تعالى في الخلق لا يزيغ عنها إلا هالك.
ومن نعم الله تعالى على بني البشر أن جعل النكاح المشروع لا السفاح الممنوع أساس العلاقة بين ال
... Show More