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Performance Evaluation of Small Scale Air-Conditioning System Using R22 and Alternative Refrigerants
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A mathematical model has been formulated to predict the influence of high outdoor air temperature on the performance of small scale air - conditioning system using R22 and alternative refrigerants R290, R407C, R410A. All refrigerants were investigated in the cooling mode operation. The mathematical model results have been validated with experimental data extracted from split type air conditioner of 2 TR capacity. This entailed the construction of an experimental test rig which consists of four main parts. They are, the refrigeration system, psychrometric test facility, measuring instrumentation, and auxiliary systems. The conditioned air was maintained at 25 0C dry bulb and 19 0C wet bulb for all tests. The outdoor ambient air temperature was varied from 35 0C to 55 0C in 5 0C increments. The study showed that R290 is the better replacement for R22 when the air conditioning system works under high ambient temperature. It has better performance as a drop in refrigerant. R407C has the closest performance to R22, followed by R410A.

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Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
The Entrepreneurial Performance of an organization in Accordance with Green Human Resources Management C A field Research in Iraq Drilling Company
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              The research aims to determine the role of green human resource management dimensions of (employment Green, training and development, green, performance evaluation Green, compensation and green bonuses) in the performance leadership of the organization dimensions of (advance planning, efficiency, effectiveness, index pioneering, renovation and modernization), Search of paramount importance because it addresses an important and modern issue in performance leadership, namely green management of human resources, aware of the importance of the subject and expected results of the company under study, an analysis of the data obtained through field visits in

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Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Towards building an educational system free of scientific corruption (Applied study in a sample of colleges of higher education in Iraq within the framework of the government program and the directions of the Supreme Council for Combating Corruption)
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Nations are developed with education and knowledge that raise the status of society in its various segments, beyond that it leads to underdevelopment and deterioration in various sectors, whether economic, health, social, etc. If we considered the general name of The ministry of Education & Scientific Studies, then the second part seems to be not functioning, since scientific research has no material allocation and remains based on the material potential of the university professor. As for the first half of the topic, the reality of the situation reveals problems related to the Holy Trinity of Education which is (Professor - Student - the scientific method) where universities suffer at the present time from this problem, and

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Violet Laser Irradiation Effect on The Optical Properties of Cobalt oxide (CoO<sub>2</sub>) Thin Films deposited via Semi-Computerized Spraying System
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Abstract<p>The existing investigation explains the consequence of irradiation of violet laser on the optic properties of (CoO<sub>2</sub>) films. The film was equipped by the utilization of semi-computerized spray pyrolysis technique (SCSPT), it is the first time that this technique is used in the preparation and irradiation using a laser in this technique. From the XRD analysis, the crystalline existence with trigonal crystal system was when the received films were processed by continuous violet laser (405 nm) with power (1W) for different laser irradiation time using different number of times a laser scan (0, 6, 9, 12, 15 and 18 times) with total irradiation time(0,30,45,60,75,90 min</p> ... Show More
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Publication Date
Thu Dec 31 2015
Journal Name
Al-khwarizmi Engineering Journal
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

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Publication Date
Tue Feb 17 2026
Journal Name
Misan Journal For Physical Education Sciences
An analytical study of the percentage of performance contribution of some defensive skills by playing positions (1,5,6) for the free player (libero) in volleyball
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The game of volleyball, like all other sports, has been made by new amendments, the most important of which is the system of what is not the system of the free player in 1998, which gave added importance to the skills of receiving the transmission and defending the stadium being one of the important skills where the law allowed the free player to move and position in the back positions of the stadium Limited support mainly defensive skills. This is to make the state of stability and balance between defensive and offensive skills, which helps in the development of the game and make it exciting and enjoyable for players and fans. Therefore, the researchers decided to shed light by identifying the percentage of the contribution of the free pla

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Publication Date
Sat Mar 27 2021
Journal Name
مجلة دراسات ويحوث التربية الرياضية
Hypoxic exercises by using (training mask) and its effect on the (PMA) and some physiological indicators and achievement for 1500m runners
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Hypoxic training, which in turn is one of the methods adopted in sports training methods, especially in activities that depend on the aerobic system in its performance, which includes training with a lack of oxygen by reducing its molecular pressure, since this method targets functional organs and works temporary responses during training and permanent responses After training as an adaptation to these devices as a result of training in this way, the study aimed to identify the effect of hypoxic exercises using the training mask and the extent of the change in some biochemical indicators, in addition to that to identify the effect of these exercises on the indicator of energy expenditure and )VMA) and the achievement of the effectiveness of

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Publication Date
Tue Feb 17 2026
Journal Name
Sciences Journal Of Physical Education
Individual analysis of kinetic response variables according to the measurement of the H7 system for the best jumping players in the national basketball team 2021
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Publication Date
Sat Sep 23 2023
Journal Name
Sciences Journal Of Physical Education
Individual analysis of kinetic response variables according to the measurement of the H7 system for the best jumping players in the national basketball team 2021
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The skill scale in most of sport activity monitoring a lot of dynamic behaviours conducted with playing situations that help the excerpt's in sport field to evaluate and put right solutions ,soccer one of games that studies in third stage in college and take skills ,dribbling , passing, shooting these skills helps to execute the plans in game ,the researchers notice that there is no test measure the skills of the game in the beginning of the first semester especially in the method of soccer in physical education college and the problem of the research were by answering the question that is there test connect between one or more that one of skill to measure the ability of students to execute the plans in soccer and the conclusion was the bui

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Publication Date
Wed Mar 01 2017
Journal Name
International Communications In Heat And Mass Transfer
Optimization, modeling and accurate prediction of thermal conductivity and dynamic viscosity of stabilized ethylene glycol and water mixture Al 2 O 3 nanofluids by NSGA-II using ANN
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In this study, multi-objective optimization of nanofluid aluminum oxide in a mixture of water and ethylene glycol (40:60) is studied. In order to reduce viscosity and increase thermal conductivity of nanofluids, NSGA-II algorithm is used to alter the temperature and volume fraction of nanoparticles. Neural network modeling of experimental data is used to obtain the values of viscosity and thermal conductivity on temperature and volume fraction of nanoparticles. In order to evaluate the optimization objective functions, neural network optimization is connected to NSGA-II algorithm and at any time assessment of the fitness function, the neural network model is called. Finally, Pareto Front and the corresponding optimum points are provided and

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Publication Date
Mon Apr 03 2023
Journal Name
Chemistryselect
Development and Validation of Spectrophotometric Methods for the Quantitative Determination of Doxycycline Hyclate in Pure Form and Pharmaceutical Formulations Using Flow‐Injection and Batch procedures: A Comparative Study
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Abstract<p>Doxycycline hyclate is an antibiotic drug with a broad‐spectrum activity against a variety of gram‐positive and gram‐negative bacteria and is frequently used as a pharmacological agent and as an effector molecule in an inducible gene expression system. A sensitive, reliable and fast spectrophotometric method for the determination of doxycycline hyclate in pure and pharmaceutical formulations has been developed using flow injection analysis (FIA) and batch procedures. The proposed method is based on the reaction between the chromogenic reagent (V<sup>4+</sup>) and doxycycline hyclate in a neutral medium, resulting in the formation of a yellow compound that shows maximum absorbance at 3</p> ... Show More
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