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 present study aimed to identify the problems thatthe students of College of Education, for women in Iraqia university are suffering from and how to overcome them. thesample of the study contained of (392) student which forms (20%) of the basic sample which is (2180) student, distributed on the six departments of the college they have been chosen randomly and the researcher has used the descriptive analytic method by applying one contains (67) items distributed on six fields,they are as follows: study skills field, academic field, curriculums field, students- teacher relationship field, examinations field, students family field,.
The study has come with
... Show Moreيهدف البحث لمحاولة دراسة واقع ادارة الوقت لدى عينه من رؤوساء الأقسام العلمية في كليات ومعاهد هيئة التعليم التقني اذ بلغ حجم العينة (47% ) فرداً تم احتيارهم عشوائياً من (15) كلية ومعهد موزعة في (69 من محافظات القطر وبلغ حجم عينة البحث (17%) من عدد رؤوساء الاقسام العلمية في الهيئة ، ولغرض جمع البيانات تم أعداد استمارة استبيان تمت صياغتها بشكل يؤمن توثيق الوقت الفعل
... Show MoreThe study aims to introduce at the difficulties in which delay the using of the internet In the educational process – learning , Study was conducted on a sample of students in the College of Education for Girls and the effects of variables : possession of computer , availability of the internet service , and the level of parents on these difficulties , Used for this purpose, a total sample size (400) students, distributed Departments . Results showed that the most important difficulties in which delay using of internet were : Lack of knowledge of internet availability , Lack of knowledge of the aim of using this service , and the students satisfaction that the disadvantages is more than the advantages of
... Show Moreاتجهت دول العالم الى تسخير جميع الإمكانيات والخبرات والعلوم من اجل الوصول الى مستويات متقدمة في الرياضات المختلفة ويهدف التدريب الرياضي إلى إعداد اللاعبين إعدادا جيدا تكمن مشكلة البحث من خلال خبرة الباحثتان الميدانية ومتابعة تدريبات لاعبي المدرسة التخصصية كرة اليد فقد لوحظ هناك ضعف واضح في الأداء المهاري ولابد من تطوير أوجه الضعف لتحقيق مستوى انجاز افضل . ويهدف البحث اعداد تمرينات خاصة بأستخدام جهاز ا
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The research aim to know the effect of note–taking by computer method as amentalactivators in achievement of physics subject for the first intermediate class students.
To investigate from aim of the research the research sample was chosen from the first intermediate class students in Al–mutamyzat secondary school for girls. Which belongs to the general administration for the second karkh education which randomly chosen from (9) schools for distinct female students in Baghdad. Then randomly chosen two sections form three about (80) female students at (66.667%) from total sample it’s about (120) female student in the three sections. The randomly chosen too, section (a) to represent experimental group it’s about (41) female
... Show MoreGompharena globosa L., Irisene herbistii Hook. ex Lindl. The results of this study showed that the anatomical characters of the stems epidermis and the indumentum covering different parts of the plant have an important anatomical characters such as the cell wall shape of ordinary epidermal cells also the shape and type of stomata, their presence in some taxa and abscent in others. The hairs also differentiated by their shapes and them types, either they glandular or eglandular also they are different in distribution between the different taxa or in the some taxon.
One of them one of the important books due to its containing valuable information written by the author. Information include the life of the Messenger (Peace be upon him)