Natural convection in a trapezoidal enclosure with partial heating from below and symmetrical cooling from the sides has been investigated numerically. The heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1/5, 2/5, 3/5, 4/5 are considered. The laminar flow field is analyzed numerically by solving the steady, two-dimensional incompressible Navier-Stokes and energy equations. The Cartesian velocity components and pressure on a collocated (non-staggered) grid are used as dependent variables in the momentum equations discretized by finite volume method; body fitted coordinates are used to represent the trapezoidal enclosure, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The range of Rayleigh number is (103≤ Ra ≤105) and Prandtl number is 0.7. The results show that the average Nusselt number increases with the increases of the source length.
The latest open commercial markets among countries, shift of capitals, and rise of mass economic, large international organizations, and international contracts leaded to a great increase of competition among countries for attracting capital for investments, specially among under developing countries which had bad economic situation, and which thinks that investment is the best solution to solve their old economic problems.
Developing small, and medium establishments in all economic sectors became the main economic force and natural resources for the development and growth of under developing countries. Small and medium establishments became the majority of any country establishments, and the past international experience shows t
... Show Moreأختير مشروع مزرعة فدك في محافظة النجف االشرف المستثمر من العتبة العلوية المقدسة. يقع المشروع في الجهة الشمالية شرقا ة عرض ''54.38 '57 º31 الـــــــــــى ً الغربية لمحافظة النجف االشرف بين خطي طول ''18.78 '0 º 44 الى ''53.46 '7 º44 ودائر ''17.53 '2 º32 شماال بمساحة اجمالية للمشروع تقدر بـــ 35493 هكتار لتقييم بعض الصفات الكيميائية للترب الصحراوية في تحديد دليل نوعيتها وصحتها لمشروع مزرعة فدك/ محافظة النجف االشرف، اذ تم اخذ 40 عينة سطحية
... Show Moreيهدف هذا البحث الى تقويم الأنشطة والأسئلة التقويمية المتضمنة في محتوى كتاب الحاسوب للصف الخامس الإعدادي وفق التفكير الإبداعي ومقترحات تطويرها، وذلك بالإجابة عن السؤال الآتي: ما نسبة توافر مهارات التفكير الإبداعي في الأنشطة والأسئلة التقويمية المتضمنة في محتوى كتاب الحاسوب المقرر لطلبة الصف الخامس الإعدادي (الاحيائي والتطبيقي، والادبي) من وزارة التربية العراقية/ المديرية العامة للمناهج في العام الدراسي (2
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“Child of today is a man of the future" this slogan is one of the most popular logos of international organizations and institutions that dealing with human beings needs in general and children needs in particular, whether these needs are educational, health, social, or economic. Children require special care and extra legal protection, since the child-raising is not the Child’s own issue, but it's the issue of the society in which he/she would integrate.
As the education and language skillsacquisition primarily associated with hearing, because human being receives most of the skills and knowledge through the hearing; that imitate sounds and learn how to speak isacquired only by hearing, so therefore the hearing - impairedchi
... Show MoreThe study aims to measure and evaluate the return and the risk formulas of Islamic finance of Jordan during the period (2000 – 2009) according of increasing importance of these banks in recent and coming years to face challenges to maximize returns and minimize risks through financing with Islamic formula to investigate of existence statistical significant relationship between returns and risking Islamic bank , has been use of financial other statistical measurement. Measuring return and risk of Islamic banks have not been widely considered ,except in few descriptive studies . The controversy among academic and professionals about hot to measure and evaluate a comprehe
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In the last two decades, arid and semi-arid regions of China suffered rapid changes in the Land Use/Cover Change (LUCC) due to increasing demand on food, resulting from growing population. In the process of this study, we established the land use/cover classification in addition to remote sensing characteristics. This was done by analysis of the dynamics of (LUCC) in Zhengzhou area for the period 1988-2006. Interpretation of a laminar extraction technique was implied in the identification of typical attributes of land use/cover types. A prominent result of the study indicates a gradual development in urbanization giving a gradual reduction in crop field area, due to the progressive economy in Zhengzhou. The results also reflect degradati
... Show Moreتبحث هذه الدراسة في المهارات االتصالية عند المحررين الصحفيين وترتيب أولويات امتالكها لديهم إذ تلعب المهارات االتصالية دورا مهما في نجاح عملية التحرير الصحفي للرسالة بكل أنواعها سواء كانت خبرا أو مقاال أو تقريرا أو تحقيقا أو حديثا ، وتتنوع هذه المهارات بين األساسية المتعلقة باالتصال والمالحظة القوية وسرعة التعبير وبين المكملة لها المتعلقة باللغة والمعنى واإلرسال واالستقبال ، وتأتي هذه الد ارسة لتركز الضوء
... Show MoreThis experiment was conducted to examine the effects of injected gibberellic acid GA3 in subcutaneous of hens neck and supplemental vitamin D3 to control basal diet on productive performance and egg shell thickness ,relative weight of egg shell of aged laying hens. Two hundred and seventy Lohmann Brown laying hens at 73 weeks of age were randomly assigned to three treatments groups. Each treatment consist of three replicates (30 hens / replicate). The treatments were : T1 control were injected subcutaneous with 0.2 ml / kg of body weight of ethanol: sesame oil solution, T2 and T3 were injected subcutaneous with 0.2 ml / kg of body weight of ethanol: sesame oil solution which contained 400 μg GA3/ kg of body weight /week during 8 weeks (tre
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