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.
This study concerns a new type of heat exchangers, which is that of shell-and-double concentric tube heat exchangers. The case studies include both design calculations and performance calculations.
The new heat exchanger design was conducted according to Kern method. The volumetric flow rates were 3.6 m3/h and 7.63 m3/h for the hot oil and water respectively. The experimental parameters studied were: temperature, flow rate of hot oil, flow rate of cold water and pressure drop.
A comparison was made for the theoretical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (- 1.6%). The percentage
... Show MoreTraditional healthcare for chronic wounds and Cold Atmospheric Plasma (CAP) treatments relies on passive dressings and large-volume stationary equipment operating with open-loop systems, which severely limits their use and confines it to specialized clinical environments. To address the lack of active thermal safety mechanisms in mobile devices, this research proposes a wearable smart plasma patch equipped with a closed-loop adaptive electronic control system to ensure safe patient care and treatment at home. The smart patch integrates real-time analog biosensors to continuously monitor skin temperature and relative humidity. An algorithm running on a microcontroller dynamically adjusts the high-voltage plasma parameters using Pulse
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In research it is an important phonemic change for the speaker to reach Ease and lightness ,wich is the kinetic follow-up , and we tried to collect the scattered matter in the various dialects.
it is studied with the ancient and modern Showing the occurrence of this term between both sides Then we clarified the phoneme explanation for this phenomenon
احتلت قضية غسيل الاموال أهمية كبيرة على الساحة الاقتصادية العالمية خلال الفترة الاخيرة إدراكا من المجتمع الدولي لأثارها السلبية على الاستقرار الاقتصادي و خاصة على الاستثمار المحلي و الدولي و لذلك يتزايد الاهتمام بها و سبل مواجهتها من قبل العديد من الدول و المنظمات الدولية و المراكز المالية الكبرى , حيث تهدد هذه الظاهرة الاقتصاد العالمي و خاصة اقتصاديات العالم النامي و من بينها الاقتصاديات العربية .
ان
... Show MoreIn research it is an important phonemic change for the speaker to reach Ease and lightness ,wich is the kinetic follow-up , and we tried to collect the scattered matter in the various dialects
ملخص البحث
العولمة ظاهرة اقتصادية سياسية اجتماعية لها انعكاساتها المختلفة على المجتمعات وعلى منظمات الأعمال في مختلف دول العالم، هذه الظاهرة أدت إلى المزيد من النتائج التي زادت منظمات الأعمال في الدول الغنية غناً وزادت منظمات الأعمال في دول العالم الثالث فقر، وقد ترتب على ذلك نتائج ايجابية لدى المجتمعات الغربية والمؤتلفة معها بسبب سيطرة منظمات الأعمال في تلك الدول على الأسواق في البلدان الن
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The research intended to take into consideration the phenomena of employing the temporary employees through the business organization increasingly, which has become one of the most apparent features of the contemporary strategy of the human resources management. It depends on the analytical descrptive Approach to meet the research problem which has been focalized around the dispute praising regarding the phenomena of the temporary employment and its dimensions and challenges which can be faced by the management of human resources as a result .The importance of the research is represented as one of rare research which confronts to the phenomena of the temporary employment in the Iraqi business environment. The most prominent objec
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The researcher seeks to know the extent of applying the concept of design by Iraqi electronic press sites to provide media product with the acceptance of their browsers and ensure their repeated visits to such sites in the framework of the guiding rules for laser browsing. The researcher uses analytical study on a sample of six Iraqi electronic newspaper sites to identify the general features of their design and the methods of distribution of the structural elements of the pages. The researcher also conducts a field study on a sample of the surfers of electronic newspaper sites to see the extent of their evaluation to their design and the degree of their satisfaction.