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Experimental Study on the Effect of Insertion of Copper Lessing Rings in Phase Change Material (PCM) on the Performance of Thermal Energy Storage Unit
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Abstract

One of the most suitable materials to be used in latent heat thermal energy storage system (LHTES) are Phase change materials, but a problem of slow melting and solidification processes made many researchers focusing on how to improve their thermal properties. This experimental work concerned with the enhancing of thermal conductivity of phase change material. The enhancing method was by the addition of copper Lessing rings in phase change material (paraffin wax). The effect of diameter for the used rings was studied by using two different diameters (0.5 cm and 1cm). Also, three volumetric percentages of rings addition (3%, 6% and 10%) were tested for each diameter. The discharging process was done with four velocities for each case. The obtained results indicated that the maximum volumetric percentage gave a diminished time for melting and maximized the heat transfer in both PCM and air sides as compare with the case of no rings, but the effect of these rings had lower effect on the solidification time. In case of 1 cm rings diameter minimum time for melting was obtained for both 3% and 6% volumetric percentages as compared with the same percentages in case of 0.5 cm diameter rings, while the latter with 10% volumetric percentage overcomes the 1 cm diameter rings for the same previous percentage. Also it can be seen that the minimum velocity (v=1m/s) gave the utmost outlet temperature and with the maximum one (v=3m/s), the minimum solidification time achieved.

Keyword: Thermal energy storage systems, Latent heat storage, Phase change materials, Heat transfer enhancement.

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Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Effect of the documentary credit opening procedures on The obligate of time limits prescribed by the contract
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This research aims to analyze the effect between letter of credit opening  and implementation procedures which considered one of the most important Foreign services submitted by bank institutions to their customers on Time contracted time limit commitment contract by some Iraqi commercial banks, descriptive analytical method used in This research The questionnaires designed a tool main research to gather information to get to know the effect ,  Seventy questionnaire forms were distributed, sixty seven forms were analyzable , The answers were analyzed by the arithmetic mean and standard deviation and test the level of influence between variables simple linear regression. The result showe

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Publication Date
Fri Jun 01 2018
Journal Name
Journal Of Engineering
Experimental Study of Optimum Chilled Water Distribution Configuration in Air Conditioning Terminal Unit Using RSM Technique
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The distribution of chilled water flow rate in terminal unit is an important factor used to evaluate the performance of central air conditioning unit. A prototype of A/C unit has been made, which contains three terminal units with a complete set of accessories (3-way valve, 2-way valve, and sensors) to study the effect of the main parameters, such as total water flow rate and chilled water supply temperature with variable valve opening. In this work, 40 tests were carried out. These tests were in two groups, 20 test for 3-way valve case and 20 test for 2-way valve case. These tests were performed at three levels of valve opening, total water flow rate and water supply temperature according to the design matrices establis

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Publication Date
Fri Oct 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The effect of applying total quality management on the competitiveness from the point of view of the front-rows employees for customer service (An analytical study of Palestinian local banks)
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The study aimed to identify the effect of Total Quality Management on enhancing competitiveness through the opinions of employees of the front- rows of customer service in local Palestinian banks, the researcher adopted an analytical descriptive method through developing a special questionnaire to accomplish the study’s objectives and answer its questions. The study involved all the Palestinian local banks, with their scattered branches in West Bank. The study sample consisted of 3470 executive employees for banking services out of 4753 employees, in the rate of 73%, and the study sample reached (485) employees who were randomly selected working in the front -rows to provide services in the local Palestinian banks during the ye

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Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Enhancement of Hoisting System Performance
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In this paper it is required to enhance the performance of a mechanical system (here: a Hoisting System) where it is preferred to lift a different payloads with approximately the same speed of lifting and keeping at the same time the good performance, and this of course needs some intelligence of the system which will be responsible on measuring the present load and taking into account the speed and performance desired in order to achieve the requirements or the criteria. The process therefore is a Mechatronics System design which includes a measuring system, a control or automation technique, and an actuating system. The criteria built here in this research using a given Hoist system's characteristics and parameters and changing one of

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Publication Date
Sun Jan 01 2023
Journal Name
Technologies And Materials For Renewable Energy, Environment, And Sustainability: Tmrees23fr
The effect between combination of cold plasma and gold nano material on blood components
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A simple low-cost approach at various exposure times was utilized to generate cold plasma in the aim to fabricate AuNPs. UV-Visible spectra and X-ray diffraction were used to characterize the nanoparticles (XRD). Surface Plasmon resonance was observed in the synthesized AuNPs at 530, 540, and 533 nm. For all samples, the patterns of XRD show very intensive peaks implying the fcc crystalline structure of AuNPs. The average crystallite size of AuNPs is ranging between 20-30 nm. The observation of morphology by FESEM revealed the spherical formation of AuNPs. Doses of 100 and 200 ppm of AuNPs were adapted to investigate their effect on the blood-mixture with and without a 20-second of cold plasma exposure. The WBC components in the blood

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Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Impact of the global financial crisis on the efficiency of activity of the Iraqi Stock Market, "An Empirical Study for the period 2006-2008”
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Abstract
  financial market occupy very important place in the economic activity all over the world countris, and its importance increased with considerable technological progress in the world of transportation ,communications and information where its impact have spread over the whole world, which led to link the international economy in a kind of international relations so that the open policy became the prevailing trend in national and regional economies within the framework of the new world order.

the international economy has faced the financial crisis, global, that hit all world economies although the United States is the center of the crisis and the starting spark for it w

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Publication Date
Wed Dec 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Silver-Zinc Zeolite Incorporation on Some Properties of Condensation Silicone Impression Material
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Background: elastomeric impression materials are indicated when a high degree of accuracy is required, due to their excellent properties like details reproduction, dimensional stability and tear strength but with main two disadvantages those are their hydrophilicity as well as the absence of antibacterial activity. This study aimed to evaluate the effect of incorporation of 0.5% wt Ag-Zn zeolite into condensation silicone through the following tests; setting time, dimensional stability, reproduction of details, wettability, and hardness . Materials and methods: one hundred specimens were constructed of condensation silicone, divided into two groups for the first 50 specimens one0.5% by wt Ag -Zn zeolite was added, keeping the other fifty sp

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Publication Date
Wed Jun 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of Optiglaze Coating on the Staphylococcus aurous and Porosity of Heat Cured Acrylic Material
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Background: Polishing technique for acrylic resin material have great effect on properties of acrylic material and bacterial colonization such as staphylococcus aurous, which are responsible for many acrylic prosthetic infections such as the commonly ocular infections. Ineffective polishing technique could affect roughness and subsequently porosity of acrylic materials.So, a new effective method for polishing acrylic was used depending on the use of optiglaze coating material. So, this study aimed to evaluate the effect of optiglaze polishing on porosity of acrylic resin material and staphylococcus aurous activity in comparison to conventional polishing technique. 

Materials and methods: Specimen(n=120) were prepared :20 spe

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Publication Date
Tue Aug 15 2023
Journal Name
Al-academy
Effect of partial substitution of alkaline oxides with lithium oxide (Li2O) on low-temperature ceramic glaze
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The research aims to study the effect of adding (Li2O) to an alkaline glaze containing (K2O, Na2O). Although all the alkaline oxides have common properties, each oxide has something that distinguishes it. The molecular weight of (Li2O) is two times less than that of (Na2O) and three times that of (K2O). Therefore, it is added in small proportions. In addition, it is a very strong flux, so it is not used alone, but rather replaces a part of other alkaline oxides. It was added to an alkali glass that matured at a temperature of 980CO in proportions (2.0,1.4,1.2,0.8,0.4%) instead of (Na2O), using lithium carbonate (Li2CO3) as an oxide source. The glazes mixtures were applied to a white pottery body, and the samples were fired and cooled acc

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Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of exercising occupational hypocrisy on organizational strategic success: An Empirical study on university of kufa faculty of administration and economic
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This research aims to identify the relationship between occupational hypocrisy and organizational strategic success, It was done by analyzing the correlations and influence between variables,  applied to a random sample of university professors at the University of Kufa faculty of administration and economic.

 The main tool for data collection is the survey were questionnaires were distributed randomly to the professors , and (43) questionnaires were returned, and test its validity by using (SEM) (Structural Equation Modeling), Hypothesis has been tested by using Statistical Package for Social Sciences (SPSS v. 18), The research found a set of conclusions:(The occupational hypocrisy has

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