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).
أن هذه الدراسة هي دراسة نظرية اهتمت بتقديم مدخل معاصر لمنظمات الأعمال، يمكن أن يعتمد علية من أجل تحقيق الريادة و البقاء. وذلك من خلال اعتماد مدخل الهدم الخلاق و تقديم أنموذج قادر على التفاعل مع البيئة بكل ما تقدمه من فرص وتحديات.
وتم تقسيم هذه الدراسة إلى ثلاثة مباحث،تناول المبحث الأول منهجية الدراسة. وبينما تناول المبحث الثاني توضيح مفهوم الهدم الخلاق والعناصر المكونة لهذا المدخل وأخيراً
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Ibn Khaldun is one of the best Arab Muslims scientists who participated in establishing Arabic Muslims heritage in all different disciplines & directions specially in sociology, neurological & his political theories which showed the development of Arabic philosophy in all scientific disciplines specially his introduction
Abook of alzmkchri (AL-Mefsal) considers one of the most book familiarities among grammarians whom begin to explain it importance kitab AL-Takhmair for Khwarizmi separated opinions in grammatical schools that dealt with.
Arabic humanity heritage had considered as a treasure of artistic, literary aspects, which is full of energies to embody investment by suitable historical ideology.
Theatre, art can be used, corresponded to make special essay reflecting a desire to establish cultural notification.
السياسة الداخلية لعراق ما بعد الانتخابات 2010 دراسة في الثوابت والمتغيرات
The historian, Professor Dr. Abdullah Al-Fayyad, left a huge legacy of knowledge product that scholars and stakeholders benefited from in the field of Islamic historical and modern studies,
Arabic humanity heritage had considered as a treasure of artistic, literary aspects, which is full of energies to embody investment by suitable historical ideology.
Theatre, art can be used, corresponded to make special essay reflecting a desire to establish cultural notification.
The effect of 5555 strategy on reading comprehension among 4th preparatory students Assist. Prof. Dr. Hassan Khilbas Hammadi College of Education Ibn Rushd – The University of Baghdad Assistant Lecturer. Waleed Khaled Talib Directorate – General For Education Province Of AL - Anbar The purpose of study is to identify the effect of 5555 strategy on reading comprehension among 4th preparatory students. To do this, null hypothesis was postulated. The author hypothesize that there is no a statistically significant difference at (0.05) level between experimental group's scores who study reading comprehension subject following the 5555 strategy and control group's scores who study the same subject following the traditional method in readin
... Show MoreThe present study aimed at examining the factors that affect the choice of A major among a sample of BA fe(male) students at the levels 3-8 in King Abdulaziz University (KAU), in Jeddah, Saudi Arabia. To meet this objective, a descriptive survey method was used together with a questionnaire that consisted of 4 axes to answer the central question: What are the factors affecting the choice of a major at the university? Results have shown that the item that measured the students’ ability to choose the major ranked (First); it was concerned with the effect on the students' choice of his/her major in the university. On the last position and with respect to this effect came the professional tendencies and desires. Results have also shown tha
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The purpose of the study is to identify the teaching techniques that mathematics' teachers use due to the Brain-based learning theory. The sample is composed of (90) teacher: (50) male, (40) female. The results have shown no significant differences between male and female responses' mean. Additionally, through the observation of author, he found a lack of using Brain-based learning techniques. Thus, the researcher recommend that it is necessary to involve teachers in remedial courses to enhance their ability to create a classroom that raise up brain-based learning skills.