The two-dimensional transient heat conduction through a thermal insulation of temperature dependent thermal properties is investigated numerically using the FVM. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner surface with a step change in temperature and subjected at its outer surface with a natural convection boundary condition associated with a periodic change in ambient temperature and heat flux of solar radiation. Two thermal insulation materials were selected. The fully implicit time scheme is selected to represent the time discretization. The arithmetic mean thermal conductivity is chosen to be the value of the approximated thermal conductivity at the interface between adjacent control volumes. A temperature dependent specific heat capacity proposed by a 4th Degree polynomial is fitted. A good agreement is obtained when the predicted results are compared with those obtained from the analytical solution.
يتضمن ھذا البحث تحضير وتشخيص بعض المعقدات الفلزية التي تحوي على ليكاندات مختلطة ل (Amoxicillin)( Axn (و(Picoline-٣) (Pic-٣ (وقد تم دراسة ھذه المعقدات بالطرائق الطيفية (اIشعة تحت الحمراء و اIشعة المرئية –فوق البنفسجية والتوصيلية الموIرية والحساسية المغناطيسية ، ومن نتائج ھذه الدراسات التشخيصية امكن اعطاء الصيغة المقترحة العامة لھذه المعقدات و كاIتي
انتخابات الرئاسة الامريكية : الالية والاهداف مع اشارة خاصة الى انتخابات 2008-2012
Developed and underdevelopment countries, on equal terms, face the problem of budget deficiency. Budget deficiency means that the public expenditure surpasses the public revenues. This, on the international level, is one of the most serious economic problems with many direct effects on the national economy, and depends, basically, on its finance chosen method. Looking for a solution to this problem, for this reason and many other ones, has been highlighted in spite of the many attempts to reduce the role of the governmental expenditure. Budget deficiency can not be attributed to a single unique cause since it is complex phenomenons the causes of which are related to many factors contribute to its occurrence, some of which refer t
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Maulticollinearity is a problem that always occurs when two or more predictor variables are correlated with each other. consist of the breach of one basic assumptions of the ordinary least squares method with biased estimates results, There are several methods which are proposed to handle this problem including the method To address a problem and method To address a problem , In this research a comparisons are employed between the biased method and unbiased method with Bayesian using Gamma distribution method addition to Ordinary Least Square metho
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Abstract
Oil is the most important natural resources in Iraq and represents the goal to others as well as Iraqi people. It is gift from God to all Iraqi people now and future. So we must maintain it and invest its revenue that achieve development in country and ensure the next generations' rights in it without external costs or negative externalities from extracted and invested it.
The most problems that we attempt to solve by this research are the exhausted, environmental degradation and theft from next generation that produced with oil contracts between Iraq and foreign companies. From here was th
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In this study, we made a comparison between LASSO & SCAD methods, which are two special methods for dealing with models in partial quantile regression. (Nadaraya & Watson Kernel) was used to estimate the non-parametric part ;in addition, the rule of thumb method was used to estimate the smoothing bandwidth (h). Penalty methods proved to be efficient in estimating the regression coefficients, but the SCAD method according to the mean squared error criterion (MSE) was the best after estimating the missing data using the mean imputation method
Abstract:
Most of the studies on this subject, small industrial projects, by researchers and scholars in the economic field show the great and increasing importance of doing this kind of projects, the extent of which can be determined by the contribution of these projects to indicators and macroeconomic and sectorial variables. So this research aims to show the extent of the economic contribution of projects in selected international experiences and in the Iraqi economy. As international experiences have provided the opportunity for the progress and growth of small projects in their economies, which led to an increase in the contribution of these projects in the recruitment of economically active manpower, in added
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the financial resources represent a basic factor of production ;It is obvious that the housing sector needs the resources to finance the building operation to produce all the housing units. Finance is the cornerstone of any housing strategy , as its successes dependent on the success of the financing methods and the creation of charnels and effective methods for the provision of the required finances for both individuals and instantly concerned with the production of housing units. The kinds of financial institutions vary from one country to another according to the nature of the economic and financial system. The lending conditions also vary as well as the capital cost of the housing units needed The housing operations is concer
... Show MoreThe study of biopolymers and their derivative materials had received a considerable degree of attention from researchers in the preparation of novel material. Biopolymers and their derivatives have a wide range of applications as a result of their bio-compatibility, bio-degradability and non-toxicity. In this paper, chitosan reacted with different aldehydes(2,4 –dichloro- benzaldehyde or 2-methyl benzaldehyde), different ketones (4-bromoacetophenone or 3-aminoacetophenone) to produce chitosan schiff base (1-4) . Chitosan schiff base (1-4) reacted with glutaric acid or adipic acid in acidic media in distilled water according to the steps of Fischer and Speier to produce compounds (5-12)
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