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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
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The effect of unsecured use of chemical pesticides on the environment and health in Iraq
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The wide use of pesticides in recent years leads to rapid distribution of these pollutants in the environment (air, water and soil).They were transported by means of air or water to biological ecosystems. They become more toxic through the processes of biological magnification while some of them persist for along period.The aim of this work is to show the negative effect that chemical pesticides causes, and in the same to show their side effect on the environment and health in Iraq. We could conclude that the bad use of these chemicals could cause an urgent impact now or in the future. Governmental offices dealing with these materials should take the right measures to minimize the danger and the misuse of these chemicals by seeking alternat

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Publication Date
Sun Dec 07 2014
Journal Name
Baghdad Science Journal
The effect of temperature and chemical solutions on the Compressive strength of particulate hybrid composites
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In this work a hybrid composite materials were prepared containing matrix of polymer (polyethylene PE) reinforced by different reinforcing materials (Alumina powder + Carbon black powder CB + Silica powder). The hybrid composite materials prepared are: • H1 = PE + Al2O3 + CB • H2 = PE + CB + SiO2 • H3 = PE + Al2O3 + CB + SiO2 All samples related to electrical tests were prepared by injection molding process. Mechanical tests include compression with different temperatures and different chemical solutions at different immersion times The mechanical experimentations results were in favour of the samples (H3) with an obvious weakness of the samples (H1) and a decrease of these properties with a rise in temperature and the increasing

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Crossref
Publication Date
Sun Jan 01 2023
Journal Name
International Journal Of Research In Social Sciences & Humanities
The Effect of Reporting About Value Creation on the Earnings Quality of Iraqi Economic Entities
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The study aims to measure the impact of reporting on value creation on the earnings quality of the economic unit by presenting and discussing the conceptual aspects of the value creation process through multi-capital and the importance of reporting it in Iraqi private banks in addition to presenting and analyzing the concept of profit quality and its measurement models. Therefore, the checklist prepared for this purpose was used based on previous studies related to the subject in order to determine the level of reporting of the research sample banks by analyzing the content of the annual reports of those banks as well as adopting the Tobin's Q scale to measure the value of the economic unit and then using some statistical models to

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Crossref
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
On The Dynamical Behavior of a Prey-Predator Model With The Effect of Periodic Forcing
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The dynamical behavior of a two-dimensional continuous time dynamical system describing by a prey predator model is investigated. By means of constructing suitable Lyapunov functional, sufficient condition is derived for the global asymptotic stability of the positive equilibrium of the system. The Hopf bifurcation analysis is carried out. The numerical simulations are used to study the effect of periodic forcing in two different parameters. The results of simulations show that the model under the effects of periodic forcing in two different parameters, with or without phase difference, could exhibit chaotic dynamics for realistic and biologically feasible parametric values.

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Publication Date
Thu Dec 14 2023
Journal Name
Malaysian Journal Of Mathematical Sciences
The Effect of Alternative Resource and Refuge on the Dynamical Behavior of Food Chain Model
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This article examines and proposes a dietary chain model with a prey shelter and alternative food sources. It is anticipated that mid-predators' availability is positively correlated with the number of refuges. The solution's existence and exclusivity are examined. It is established that the solution is bounded. It is explored whether all potential equilibrium points exist and are locally stable. The Lyapunov approach is used to investigate the equilibrium points' worldwide stability. Utilizing a Sotomayor theorem application, local bifurcation is studied. Numerical simulation is used to better comprehend the dynamics of the model and define the control set of parameters.

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Publication Date
Mon Jun 22 2020
Journal Name
Baghdad Science Journal
Studying the Effect of Magnesium Oxide Nanoparticles Prepared on the Surface of Poly Methyl Methacrylate
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          In this paper, magnesium oxide nanoparticles (MgO NPS) have been prepared and characterized and its concentration effect has been studied on polymers surface (MgO NPS). The results showed that the degradation of poly methyl methacrylate increased when using such metal oxide. The results also showed that the metal oxide increased the degradation of poly methyl methacrylate. X-ray diffraction, scanning electron microscopy, atomic force microscopy were used to study the morphological characteristics and size of nano MgO particles analysis.  Films were prepared by mixing the different masses of MgO NPS (0.025, 0.05, 0.1, 0.2 and 0.4) % with a polymer solution ratio (W/V) 7 %. Photo-

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Scopus (1)
Crossref (1)
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Publication Date
Tue Oct 01 2024
Journal Name
Association Of Arab Universities Journal Of Engineering Sciences
Interactive Design of Pediatric Hospital spaces
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Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
Simplification of new fashion design methods
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Simplification of new fashion design methods

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Design and construction of Video extractor
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Design and construction of video extractor circuit require an understanding of several parameters, which include: Selector circuit, extracting circuit which contains sampling signal and multiplexing. At each radar pulse, the video signal is fed to one of the selector. The fast filter has a pass –band from 190 Hz to 1800 Hz. These frequencies correspond to targets having radial velocities laying between and 10 Kph and 200 Kph.Slow filter: 60 Hz to 230 Hz for radial velocities laying between 3.5 and 13 Kph.The video- extractor is organized in four PCB CG (A-B-C-D) each one having 16 selector. The sampling signal (ADS) (1-2-3-4) control the 4-line-to-16-line decoders. 8 multiplexers of 8 inputs each, are required for the multiplexing of the

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Crossref
Publication Date
Thu Apr 14 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
Study The Effect of α-amylase Inhibitors Isolated from Plant Sources on Some Mold.: Study The Effect of α-amylase Inhibitors Isolated from Plant Sources on Some Mold.
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Activity test of the inhibitors purified from barley and broad beans crop proved the inhibition activity against 6 types of rots Pencillium ssp and Aspergellusflavus and Aspergillus niger and Fusarium solani and Fusarium semitectum and Mucor with three concentrations 0.1 and 0.2 and 0.3 mg/ml, where the inhibitor purified from the second peak of broad beans proved that it had a higher inhibition activity against the growth of test rots which were 53.75 and 62.5 and 78.5 and 76.25 and 84 and 18.8% respectively, at 0.3 mg/ ml followed by the first peak of the inhibitor purified from broad beans the inhibition activity were 43.75 and 50 and 62.96 and 75 and 80 and 12.5 then the inhibitor purified from barley in which the inhibition activity

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