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An Experimental Study of the Effect of Vortex Shedding on Solar Collector Performance
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In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation conditions was examined. The variation of angles of attack and wind velocity leads to different values of vortex loading coefficients and shedding frequencies. The relation between the dynamic characteristics and solar collector performance was evaluated. The finite element method was used to estimate the dynamic characteristic of the solar collector in addition to experimental work to evaluate the relation between the dynamic behavior of the collector and its performance.

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Publication Date
Sun Dec 17 2017
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect of Different Reinforcements on the Damping Properties of the Polymer Matrix Composite
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In this research, damping properties for composite materials were evaluated using logarithmic decrement method to study the effect of reinforcements on the damping ratio of the epoxy matrix. Three stages of composites were prepared in this research. The first stage included preparing binary blends of epoxy (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5% and 10%). It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that; it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. The second stage

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Publication Date
Mon Aug 27 2018
Journal Name
Al-khwarizmi Engineering Journal
Efficiency Enhancement of a Dual-axis Solar PV Panel Tracker Using Water-Flow Double Glazing Technique
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The fall angle of sun rays on the surface of a photovoltaic PV panel and its temperature is negatively affecting the panel electrical energy produced and efficiency. The fall angle problem was commonly solved by using a dual-axis solar tracker that continually maintains the panel orthogonally positioning to the sun rays all day long. This leads to maximum absorption for solar radiation necessary to produce maximum amount of energy and maintain high level of electrical efficiency. To solve the PV panel temperature problem, a Water-Flow Double Glazing WFDG technique has been introduced as a new cooling tool to reduce the panel temperature. In this paper, an integration design of the water glazing system with a dual-axis tracker has been ac

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Publication Date
Fri Apr 01 2022
Journal Name
Baghdad Science Journal
Study the Efficiency of Two Concentrations from Algae Cladophora glomerata Extract on the Giardia lamblia parasite
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Giardia lamblia parasite was isolated from the diarrhea samples of patients with Giardiasis dysentery and was developed in HSP media, four mice groups have been used to find in vivo efficacy of two concentrations (128,256) mg/ml of chlorophorm extracts from Cladophora glomerata algae against Giardia lamblia parasite  as compared with (Flagyl) by measuring several biochemical markers as ( GPT and GOT) enzymes ,sodium ,potassium and iron concentration as well as counting the number of parasitic cysts in each mice groups. The results demonstrate that levels of GPTA GOT enzymes have been decreased in mice treated with algal extract. As for the concentration of the Sodium, Potassium and Iron increased in mice treat

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The role of Internal Audit Standards IIA`s in improving the local guideline and its reflection on the efficiency of internal audit performance
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The function of internal auditing has become an important function that aims at achieving objectives that are compatible with these developments and changes that have occurred in many countries in the world, which required the emergence of professional associations and institutes in the profession of internal auditing. Improve the guideline of the internal audit units issued by the Federal Audit Bureau to enhance the efficiency of internal audit performance in Iraqi government units. The researchers adopted the statistical method of proving the hypothesis by constructing a questionnaire that included three main axes: supporting the senior management in adopting the current guide, and the second being the importance of improving t

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Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The effect of performance appraisal dimensions On organization confidence
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This research was designed to study effect of performance appraisal dimensions on organizational confidence.

Asset completion questionnaire was used to collect data of this research from a random simple represent forty employees who works in Iraqi Oil ministry. The main result of this research was positive relations and the effect between performance appraisal and organizational confidence. The research contains some conclusions, the main of it is unimplemented the performance appraisal results in the policies of employees in the ministry and it work in classic methods incentives and training.

The important recommendations must doing to achieve integrating between the result of pe

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Publication Date
Mon Nov 09 2020
Journal Name
Heat Transfer
Experimental performance of cooling photovoltaic panels using geothermal energy in an arid climate
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Publication Date
Thu Mar 01 2007
Journal Name
Al-khwarizmi Engineering Journal
An experimental comparative study between polypropylene and laminated lower limb prosthetic socket
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Most researchers concentrate their studies on the design, stress and pressure distributions of the prosthetic socket. A little attention is considered for the stiffness of the various materials of the prosthetic sockets. Prosthetic laminated sockets in Iraq are costly to be manufactured while polypropylene socket is relatively cheap in comparing with the laminates.

Experimental study is conducted to compare the stiffness of five prosthetic sockets made of different materials. Compression, three point flexural and tensile tests are implemented by the Testometric machine. The laminate sockets give better results in compression than polypropylene. Polypropylene gives good results in bending compared with the laminate sockets. When t

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Publication Date
Sun Jan 01 2023
Journal Name
Aip Conference Proceedings
Study the effect of curved edges on the aerodynamics performance of suction slot
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Publication Date
Fri Sep 30 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The economic feasibility of the accident insurance portfolio in the performance of insurance companies : an analytical study
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The research aims to use performance indicators and financial criteria in evaluating the economic feasibility of the company's insurance portfolios. In addition to identifying the strengths and weaknesses in portfolio's performance to enhance the strengths and address the weaknesses. This is consistent with research problem that dealt with the performance indicators, economic feasibility of company's portfolios and contributing to their improvement, reducing the financial and insurance risks associated with company's business. The research’ sample is represented by the Iraqi Insurance Company as it is one of the oldest financial institutions operating in the insurance sector. It has identified (5) insurance portfolios (marine, engineer

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Publication Date
Fri Sep 15 2023
Journal Name
Journal Of Baghdad College Of Dentistry
Osseointegration effects of whey protein (histological and histomorphological observations): An experimental study on rabbits
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Background: Whey protein is the green-yellow colored, liquid portion of the milk, and it is also called the cheese serum, it is obtained after the separation of curd, during the coagulation of the milk. It contains a considerable amount of α-helix pattern with an evenly distributed hydrophobic and hydrophilic as well as basic and acidic amino acids along with their polypeptide chain. The major whey protein constituents include β-lactoglobulin (β-LG),α-lactalbumin (α-LA), immunoglobulins (IG), bovine serum albumin (BSA), bovine lactoperoxidase (LP), bovine lactoferrin (BLF) and minor amounts of a glycol macro peptide (GMP). Osseointegration can be defined as a process that is immune driven which leads to the formatio

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