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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
Tue Jul 11 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effect of SPAWN Strategy on the Life Skills among the Second Grade Intermediate Students
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The aim of the research is to find out the effect of the SPAWN strategy on the life skills of second-intermediate-grade students. This study stage represented the research community within the intermediate and secondary governmental daytime schools affiliated with the Directorate of Education of Diwaniyah. The experiment was applied in Al-Razai Intermediate School on a sample of second-grade intermediate students, including 66 students distributed into two groups: (32) students within the experimental group and (34) students within the control group. The two groups were equivalent with a number of variables (chronological age, intelligence test, previous information test, life skills scale). The results indicated that the two groups were

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The Effect of PDEODE Strategy on the Acquisition of Historical Concepts of First Class of Intermediate Students
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The research aims to find out the effect of PEDODE Strategy on the acquisition of historical concepts of First Intermediate Grade. To achieve this goal, the researcher has put forward this zero hypothesis: There is no statistically significant difference at the level of (05,0) between the mean of the students' marks in the experimental group who study the history subject using PEDODE strategy and that of the students' marks in the control group who study the subject according to the traditional method in the post-testing on the acquisition of historical concepts. The sample of the study consists of (62 female-students) of First Intermediate Grade in the Directorate of Baghdad Education/ Karkh2nd for the academic year 2016-2017. The sampl

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Publication Date
Sun Jan 26 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Evaluation of Financial Performance of the Iraqi Insurance Company
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Insurance Companies perform a prominent role in providing services and bolstering national economy, and they contribute in achieving the aims of the economic development plans in addition to many other social and economic benefits. So it is necessary to evaluate the activity of these companies continuously to define performance level and its nature. Financial analysis is one of the important instruments that helps in analyzing and explanation of data in such a way that enable administration to define performance level and diagnosing strength and weakness points. This study tackles the state of affairs of the Iraqi Insurance Company which is considered as one of the active national institutions, due to its distinguished role in collecting

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Transparency of government performance to the state of iraq
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The most important recommendations of this research are:-

1.The benefit of the other countries experiences about the transparency of the government performance, without depending on the transparency that imitating the other experiences; that may not fit with the Iraqi government units.

2.The Ministry of Finance has to prepare the citizen guidebook about the government performance which is considered an essential document, it should be simple and available for all the parties of relation; and for not specialized citizen for the purpose of simplifying the understanding of government performance details.

3.The benefit of the government units websites of inte

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Publication Date
Tue Dec 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Study of the Performance of Batch Reactive Distillation Column
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Batch reactive distillation was studied in packed bed column. Esterification of methanol with acetic acid to produce methyl acetate and water with homogenous sulfuric acid as a catalyst was considered. This system was chosen because the reaction is reversible and the boiling point of reactant and products are different.
The reaction was carried out with and without distillation column and shows that the reactive distillation is more efficient from the conventional process (reactor and then separation). The conversion of acetic acid and concentration of methyl acetate increase by (30.43% and 75.14%) respectively at the best condition (reflux ratio 2, feed mole ratio 2 and batch time 90 minute).
The influence of various parameters, s

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Publication Date
Fri Aug 30 2024
Journal Name
Iraqi Journal Of Science
The Migration Effect on an Eco-toxicant Model
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This paper proposes and studies an ecotoxicant system with Lotka-Volterra functional response for predation including prey protective region. The equilibrium points and the stability of this model have been investigated analytically both locally and globally. Finally, numerical simulations and graphical representations have been utilized to support our analytical findings

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Publication Date
Tue Jun 14 2005
Journal Name
Iraqi Journal Of Laser
Bending Effect on the Single Mode Optical Fibers
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Bending effects on the transmission of optical signal are investigated on a single mode
optical fiber (SMOF) of 10 m length, core radius of 5 μm and optical refractive index difference
0.003. The bending radii (R) were between 0.08 and 0.0015 m. A great decrease in the amplitude is
shown for radii below 0.01 m. Sudden break down occurs for radii less than 0.0015 m. Birefringence
(B) is difficult to measure for long fibers. Meanwhile, B was found by comparing with calibrated
fiber of the same properties but of length of 0.075 m. The results show an increase in propagation
constant (Δβ) and the decrease in beat length (Lb), and show that bending decreases the critical radius
of curvature (Rc) related to B. The chang

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Mechanical and thermal properties of cockles shell cementing material
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Mortar of ordinary Portland cement was blended with cockles shell
powder at different weight ratios to investigate the effect of powder
admixture on their strength and thermal conductivity. Results showed
that addition of cockles shell powder at 50% of mortar weight
improves hardness and compressive strength notably and reduces the
thermal conductivity of the end product. Results suggest the
possibility to incorporate cockles shell powders as constituents in
cement mortars for construction and plastering applications.

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Crossref (2)
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
Enhanced efficiency of CdTe Photovoltaic by thermal evaporation Vacuum
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Crossref (21)
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
Enhanced efficiency of CdTe Photovoltaic by thermal evaporation Vacuum
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