Computational study of three-dimensional laminar and turbulent flows around electronic chip (heat source) located on a printed circuit board are presented. Computational field involves the solution of elliptic partial differential equations for conservation of mass, momentum, energy, turbulent energy, and its dissipation rate in finite volume form. The k-ε turbulent model was used with the wall function concept near the walls to treat of turbulence effects. The SIMPLE algorithm was selected in this work. The chip is cooled by an external flow of air. The goals of this investigation are to investigate the heat transfer phenomena of electronic chip located in enclosure and how we arrive to optimum level for cooling of this chip. These parameters, which will help enhance thermal performance of electronic chip and flow patterns, through the understanding of different factors on flow patterns. The results show the relation between the temperature rise, heat transfer parameters (Nu, Ra) with (Ar, Q) for two cases of laminar and turbulent flows.
Abstract
The research aims to identify the mediator role of workplace spirituality in the relationship between psychological capital and entrepreneurial behavior: field research to a sample opinions from employees at the center of the Iraqi ministry of Oil . The importance of the current research emerged from paucity of studies that have attempted to identify and know the nature of the relationship between the variables as well as trying to find the current address and realistic problem directly affects the performance of employees in the Iraqi oil sector.
In order to achieve the goal of research the use of the analytical method (quantitative)
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Some major pollutants of polycyclic aromatic hydrocarbons (PAH) those discharged as water produced (WP) from the AlAhdab oil field (AOF) in the ponds close to it may leak to the water resources around and eventually reaches the marshes which will affect its ecosystem. Thus, this work aims to track the availability of PAH in the water resources and the Main Outfall Drain (MOD) nearby. The determination of PAH was evaluated using “High-Performance Liquid Chromatography (HPLC)”. The mean concentration of sixteen PAH in the produced water within the field was relatively high (0.01 to 10.89 g/ml) with standard deviations of (0.10.9). While, PAH outside the field were gradually diminishes down to (0.01-0.039) x10-2 g/ml which exceeds th
... Show MoreIn this paper, the Normality set will be investigated. Then, the study highlights some concepts properties and important results. In addition, it will prove that every operator with normality set has non trivial invariant subspace of .
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Corruption is a phenomenon that exists in all times and places, they appear in the developing countries and in developed countries, and in all political systems. And its repercussions and economic repercussions on the society in which it is rampant, and lead to the undermining of economic development and obstruction, is also working on increasing poverty and unemployment, as well as its role in the worsening of social problems, and political instability. And corruption is deviant behavior is illegal and contrary to the teachings of the religious and moral values. The emergence of this phenomenon is due to several reasons, including political, economic, social and cultura
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The Planning and Resource Development Department of the Iraqi Ministry of Health is very interested in improving medical care, health education, and village training programs. Accordingly, and through the available capabilities of the ministry, itdesires to allocate seven health centers to four villages in Baghdad, Iraq therefore the ministry needs to determine the number of health centers allocated to each of these villages which achieves the greatest degree of the overall effectiveness of the seven health centers in a fuzzy environment. The objective of this study is to use a fuzzy dynamic programming(DP) method to determine the optimal allocation of these centers, which allows the greatest overall effectiveness of these health centers
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In this research work an attempt has been made to investigate about the Robustness of the Bayesian Information criterion to estimate the order of the autoregressive process when the error of this model, Submits to a specific distributions and different cases of the time series on various size of samples by using the simulation, This criterion has been studied by depending on ten distributions, they are (Normal, log-Normal, continues uniform, Gamma , Exponential, Gamble, Cauchy, Poisson, Binomial, Discrete uniform) distributions, and then it has been reached to many collection and recommendations related to this object , when the series residual variable is subject to each ( Poisson , Binomial , Exponential , Dis
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البحث معني بظاهرة اللجوء من العالم الاسلامي الى العالم الغربي وما يحيط بهذه الظاهرة من تحديات سواء كانت سلبية او ايجابية والبحث يوضح احكام العقيدة الاسلامية للحكم على هذه الظاهرة التي اصبحت من النوازل في هذا العصر
Los lingüistas no árabes suelen quedar perplejos a la hora de interpretar el fenómeno de Al-ḍdad, −normalmente traducido en español como palabras autoantónimas (1)− en la lengua árabe, en el que los arabistas, y entre ellos los españoles, han quedado sombrosos ante este fenómeno. El jefe del tribunal de la defensa de mi tesis me pidió que le explicara este fenómeno según mi teoría “El esquema básico de la referencia”; pues me dijo que no podía imaginar que una palabra tuviera dos significados opuestos, y en ese momento le expliqué la palabra albayn البين que significa la separación, o la relación o el enlace que comentar
... Show MorePhonological metathesis can be defined as an alternation in the normal sequence of two sounds under certain conditions. The present paper is intended to give a detailed synchronic description of phonological metathesis in Iraqi Arabic dialect. For data collection, the researchers have adopted two naturalistic techniques, viz., observation and notes taking. A synchronic analysis is carried out to provide some evidence that describe the sequential change of phonological metathesis in the dialect under investigation. Such sequential changes of metathesized sounds are presented and tabulated. The study concludes with the following finding that this process is not limited to cases where two consonant sounds are transposed, but three consonant
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