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.
This research was designed to study effect of performance appraisal dimensions on organizational confidence.
Asset completion questionnaire was used to collect data of this research from a random simple represent forty employees who works in Iraqi Oil ministry. The main result of this research was positive relations and the effect between performance appraisal and organizational confidence. The research contains some conclusions, the main of it is unimplemented the performance appraisal results in the policies of employees in the ministry and it work in classic methods incentives and training.
The important recommendations must doing to achieve integrating between the result of pe
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يهدف البحث الحالي التعرف على اسباب السرقة لدى تلاميذ المرحلة الابتدائية كما يراها معلموهم ومعلماتهم ، وعن الاساليب المتبعة في معالجة ظاهرة السرقة من قبلهم ، ولقد شملت عينة البحث على ( 200 ) فرداً من معلمي ومعلمات تلاميذ المرحلة الابتدائية في مدينة المكلا للعام الدراسي ( 2004 ـ 2005 ) ، وقد استخدمت الباحثة استبياناً أعدته كأداة للوصول الى اهداف البحث بعد ان تم التأكد من صدقه وثباته ، استخدمت الباحثة معادلة ارتب
... Show MoreThe researcher tried to show the importance of using environmental taxes as an effective economic factor for reducing contaminators resulting from cars exhausts, and presenting a suggested pattern for environmental taxes as a nucleus and a starting point for a wider implementing of environmental taxes in Iraq. &nbs
... Show Moreي لا ماق ثحبلا فادهأ قيقحتلو ثحبلا ةنيعل نايبتسا ءارجاو فراصملل ةيلاملا مئاوقلا ليلحتب ثحاب اهمهأ ناك تاجاتنتسا ىلإ ثحابلا لصوت دقو لإ صاخ معد دوجو مدع نم ةيفرصملا رطاخملا ةراد ةروصب اهدوجو مدعو فراصملل ةماعلا تارادلاا يف اهدوجو رصتقي ثيح ،ايلعلا تاهجلا لبق نم ديزي امم ،عورفلا يف ةلاعف مدع ةجيتن عورفلا نم ةدلوتملاو فراصملا اههجاوت يتلا رطاخملا اهمهأ ناك تايصوت ىلإ ثحابلا لصوت دقو امك ،ةيفرصملا تلاماعم
... Show MoreThe past decades have witnessed a development in the concept of corporate governance and the transformation of a concept that is limited to large companies listed in capital markets in major economies to an issue that concerns all business activities in the public and private sectors in both large and small countries. The aim of this research is to propose a guide to the mechanisms and rules of governance in the municipal institutions that contributes to the activation of the internal control system to reduce the fraud and manipulation of this activity. Institutions. The research was based on the hypothesis that the implementation of the principles and rules of governance in municipal institutions lead to the contribution of the activati
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In recent years, the attention of researchers, governments and international non-governmental organizations has focused on the aggressive practices adopted by companies with the aim of evading the tax burden or from paying the tax obligations imposed on them by law, as the results of these practices are negatively affected by tax revenues. And that companies are part of the society in which they work, and they have rights and obligations, including paying taxes. The research community is the Iraqi private shareholding companies, and the research sample was 4 companies within the private sector and in the field and finance - banking, insurance, industrial and service, which are Ashur Bank, Al-Ahlia Insurance Company, Baghdad Soft
... Show MoreAddition of bioactive materials such as Titanium oxide (TiO2), and incorporation of bio inert ceramic such as alumina (Al2O3), into polyetheretherketone (PEEK) has been adopted as an effective approach to improve bone-implant interfaces. In this paper, hot pressing technique has been adopted as a production method. This technique gave a homogenous distribution of the additive materials in the proposed composite biomaterial. Different compositions and compounding temperatures have been applied to all samples. Mechanical properties and animal model have been studied in all different production conditions. The results of these new TiO2/Al2O3/PEEK biocomposites with different
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إنها وصف واقعي أو خيالي لأفعال تهدف إلى ترفيه أو تثقيف المستمع أو القارئ. (روبرت لويس ستيفنسون) يقول أحد رواد سرد القصص البارزين: هناك ثلاث طرق فقط لكتابة قصة: إما أن يختار الكاتب حبكة ثم يجعل الشخصيات تتناسب معها، أو أن يختار شخصية ويختار الأحداث والمواقف التي تُطور الحبكة. الحبكة هي التصميم أو المنطق أو البنية لنوع معين من الخطاب الذي يُطور وحداته من خلال تسلسل زمني. وهي تُعطي القصة...