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The Effect of Fin Design on Thermal Performance of Heat Sink
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      An experimental and computational study is conducted to analyze the thermal performance of heat sinks and to pick up more profound information in this imperative field in the electronic cooling. One important approach to improve the heat transfer on the air-side of the heat exchanger is to adjust the fin geometry. Experiments are conducted to explore the impact of the changing of diverse operational and geometrical parameters on the heat sink thermal
performance. The working fluid used is air. Operational parameters includes: air Reynolds number (from 23597 to 3848.9) and heat flux (from 3954 to 38357 W/m
2 ). Conformational parameters includes: change the direction of air flow and the area of conduction/convection. Six . parallel plate heat sinks are fabricated and tested in small wind tunnel: flat plate, cross-cut, perforated, perforated cross-cut, zigzag and serpentine. Three-dimensional numerical simulations using commercial available FLUENT 15 software, based on the Navier–Stokes equations standard k-ε applied turbulence model and energy equation, are acquired for forced convection of air in same heat sinks under the same experimental conditions. It is found that the numerical prediction of base temperature is in good agreement with experimental data. Results show that the Reynolds number has a significant effect on the thermal performance of the system. With increasing free stream velocity, the heat transfer coefficient increases and consequently the thermal resistance decreases. Furthermore, it is found that the heat transfer coefficient and thermal resistance are depending on heat flux. From the comparison analysis of various geometries of heat sinks, the perforated-cut heat sink showed the best thermal performance indicated heights Nusselt number and heat transfer coefficient, lowest thermal resistance.

 
 

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Publication Date
Thu Dec 31 2020
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
THE USE OF MICROENCAPSULATION TECHNOLOGY WITH COATING LAYER BY LAYER TO IMPROVE THE STABILITY OF THE Lactobacillus casei TOWARDS THE BILE SALTS AND TREATMENT HEAT.: THE USE OF MICROENCAPSULATION TECHNOLOGY WITH COATING LAYER BY LAYER TO IMPROVE THE STABILITY OF THE Lactobacillus casei TOWARDS THE BILE SALTS AND TREATMENT HEAT.
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This study aimed to improve the microencapsulation technique using a type coating the encapsulation Layer by Layer, which provide the best protection for life Lactobacillus casei in the extrusion method and use the microencapsulation of materials of the protein concentrated by protein 80% and the coating with alginate and chitosan have the results showed the variation in the difference of the binding process encapsulation yield among the types of coating through. by studying of these the effect o stability of the bio probiotic free cell and the three types coated towards three different concentrations from bile salts 0, 0.3, 0.5 and 0.7% when the periods of time different of zero and two and three hours at incubation the recorded

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The phenomenon of negative behavior has studied as a social and psychological phenomenon that effect on the performance and life of workers inside and outside the organization. The adoption of this phenomenon is studied in terms of the role of the interna
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The phenomenon of negative behavior has studied as a social and psychological phenomenon that effect on the performance and life of workers inside and outside the organization. The adoption of this phenomenon is studied in terms of the role of the internal environment of the organization in addressing this behavior, being the variables belong to the field of organizational behavior to see the results of those variables on the Iraqi organizations, since the specificities of it differ from the rest of the Arab and foreign environments. Therefore, this study focused on testing the relationship of the internal environment of the organization and its role in addressing the negative behavior of the workers.

thi

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Publication Date
Thu Dec 18 2025
Journal Name
College Of Basic Education Researches Journal
Identify the effect of exercise of the arm is the practice in the development of accurate performance skill transmission (short and long) arm of practice for students badminton
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Publication Date
Wed Jan 01 2020
Journal Name
Plant Archives
STUDY OF THE EFFECT OF COLD PLASMA ON THE REPRODUCTIVE ENDOCRINOLOGY OF MALE RATS
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Cold atmospheric plasma (CAP) is used widely in medical and biological fields because of non-thermal effected. Direct application of plasma is preferred in medical functions, so, direct application of cold plasma has obtained by the floating electrode dielectric barrier discharge (FE-DBD) system. The purpose of this paper to review the effect of (CAP) on the reproductive hormones (testosterone, LH, E2, progesterone, for male rats. The study appeared that no significant effect on E2 and progesterone hormone for all time of exposure, besides this significant difference in LH hormone (P<0.05) at 15 sec, (P<0.0001) at 30, 90 sec and (P<0.001) at 60 sec of exposure to plasma. Added to that significant difference (P<0.01) at 15, 30, 60 sec and no

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Publication Date
Sun Dec 07 2008
Journal Name
Baghdad Science Journal
The effect of doping ratio of Cu on the structural properties of CdSe Films
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Films of CdSe have been prepared by evaporation technique with thickness 1µm. Doping with Cu was achieved using annealing under argon atmosphere . The Structure properties of these films are investigated by X-ray diffraction analysis. The effect of Cu doping on the orientation , relative intensity, grain size and the lattice constant has been studied. The pure CdSe films have been found consist of amorphous structure with very small peak at (002) plane. The films were polycrystalline for doped CdSe with (1&2wt%) Cu contents and with lattice constant (a=3.741,c=7.096)A°, and it has better crystallinty as the Cu contents increased to (3&5wt%) Cu. The reflections from [(002), (102). (110), (112), and (201)]planes are more prominen

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Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
The effect of Cu concentration on some of the electrical properties of CdSe films
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The CdSe pure films and doping with Cu (0.5, 1.5, 2.5, 4.0wt%) of thickness 0.9μm have been prepared by thermal evaporation technique on glass substrate. Annealing for all the prepared films have been achieved at 523K in vacuum to get good properties of the films. The effect of Cu concentration on some of the electrical properties such as D.C conductivity and Hall effect has been studied.
It has been found that the increase in Cu concentration caused increase in d.c conductivity for pure CdSe 3.75×10-4(Ω.cm)-1 at room temperatures to maximum value of 0.769(Ω.cm)-1 for 4wt%Cu.All films have shown two activation energies, where these value decreases with increasing doping ratio. The maximum value of activation energy was (0.319)eV f

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Publication Date
Sun Oct 14 2018
Journal Name
Industrial Lubrication And Tribology
Thermal stress analysis of dry friction clutches
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Purpose

The purpose of this paper is to present an approach to compute accurately the distributions of the frictional heat generated, contact pressure and thermal stresses at any instant during the sliding period (heating phase) of the single-disc friction clutch system works in the dry condition and the complex interaction among them.

Design/methodology/approach

Numerical work was achieved using the developed elastic and thermal finite element models (axisymmetric models) to simulate the engagement of the single-disc friction clutch system.

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Publication Date
Wed Sep 30 2020
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Studying Thermal Cracking Behavior of Vacuum Residue
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   In the oil industry, the processing of vacuum residue has an important economic and environmental benefit. This work aims to produce industrial petroleum coke with light fuel fractions (gasoline, kerosene , gas oil) as the main product and de asphalted oil (DAO) as a side production from treatment secondary product matter of vacuum residue. Vacuum residue was produced from the bottom of vacuum distillation unit of the crude oil. Experimentally, the study investigated the effect of the thermal conversion process on (vacuum residue) as a raw material at temperature reaches to 500 °C, pressure 20 atm. and residence time for about 3 hours. The first step of this treatment is constructing a carbon steel batch re

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Publication Date
Fri Mar 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of the internal audit in the performance enhancing
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  After the internal audit as a tool of internal control in any organization, and helps in the evaluation of all internal control activities, as a tool to ensure compliance with the plans and policies to achieve the goals of the institution as much as possible of the efficiency, effectiveness, and should have the Internal Audit full independence and is linked to senior management, and aims to get the credibility and accuracy of information and data, and keep abreast of modern developments.

  The practical side includes the preparation of the questionnaire, which included a set of questions that fit the hypothesis of the research, was Tozeiha the research sample consisting of employees of the Internal Audit Department an

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Crossref
Publication Date
Thu Oct 01 2020
Journal Name
Biochemical And Cellular Archives
EFFECT OF EXPRESSION OF TAFAZZIN (TAZ) ON THE DEVELOPMENT OF CERVICAL CARCINOMA
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: Cervical cancer representsone of the possibly preventable cancer. The study was designed to find the possible correlation of Tafazzin on the progression of cervical carcinoma. Two groups of paraffinized blocks were included. The study group of 30 cervical tumors as well as 15 biopsies of healthy cervical tissues. After sectioning on a positive charge, immunohistochemical application (IHC) was performed to detect Tafazzin expression. Nighnty percentage (27 out of 30) of the studies group showed positive overexpression as shown in with a significant association of the expression with cervical cancer with a significant association. There is a possible role of TAZ in hastening the development of cervical cancer through different mechanisms. F

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