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Effect of Different Compressor Speeds on the Energy and Exergy of an Automobile Air-Conditioner Using R134a in the Absence and Presence of a Liquid-Suction Heat Exchanger
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Refrigerant R134a has been widely utilized in automotive air conditioning systems (AACSs); R134a has a high global warming potential (GWP) of 1430 despite having zero ozone depletion potential (ODP). Coming refrigeration systems must include refrigerants with low GWP and zero ODP. The aim of this experimental study is to evaluate the thermal performance of an (AAC) with different values of compressor speeds, i.e., (1000, 1700, and 2400 rpm) and two thermal loads, i.e., (500 and 1000 Watt) with the absence and presence of liquid suction heat exchanger (LSHX) using R134a. The results showed that adding LSHX enhanced the COP cycle by 7.18%, 10.7%, and 3.09% for the first, second, and third speed, respectively, at 500 Watt, while the enhancements were 10.27 %, 23.3 %, and 11.5 % for the first, second, and third speed, respectively, at 1000 Watt. Increasing the compressor speed decreased COP due to a reduction in RE and increased the compression effect, increasing the work done by the motor on the compressor that caused a reduction in COP. The compressor exergy destruction (X des. Comp.) decreased when LSHX was added by 6.13%, 2.22%, and 18.8% for the first, second, and third speed, respectively. However, X des. comp. increased with compressor speed due to the system’s pressure difference rise because of decreasing evaporation and increasing condensation pressures. As a result, the entropy generation increased. The increase in discharge temperature and pressure of the compressor led to a high friction force between the moving part of the compressor and the refrigerant, so the energy losses increased. Increasing the compressor speed decreased the total exergy performance of the cycle by 5.8 %, 7.5 %, and 16.7 % for the first, second, and third speed, respectively, due to increasing the compressor discharge temperature, increasing the X des. comp. and thermostatic expansion device and decreasing condenser and evaporator. Increasing X des. comp was higher than the destruction in the condenser and evaporator, which canceled the effect of others, so the total exergy performance of the cycle decreased.

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Publication Date
Sun Oct 05 2025
Journal Name
University Of Anbar Sport And Physical Education Sciences
Anxiety and its relationship to the performance of the front hand hop followed by an anterior spherical flip with a half lap on the jumping platform
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Publication Date
Fri Jan 15 2021
Journal Name
Plant Archives
STUDY OF THE EFFECT OF SPEED, DEPTH OF THE CULTIVATION AND THE NUMBER OF TIMES THE SPRING – LOADED CULTIVATOR PASSES ON SOME TECHNICAL PARAMETERS OF THE CULTIVATOR AND ON WEED CONTRO
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Publication Date
Fri Jan 01 2021
Journal Name
Plant Archives
STUDY OF THE EFFECT OF SPEED, DEPTH OF THE CULTIVATION AND THE NUMBER OF TIMES THE SPRING – LOADED CULTIVATOR PASSES ON SOME TECHNICAL PARAMETERS OF THE CULTIVATOR AND ON WEED CONTROL
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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of social audit in social performance an applied study of the views of a sample of managers and staff of Algerian business organizations
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            This research aims at clarifying the concept of social auditing, which is one of the most important reasons for its emergence is social responsibility accounting and its role in measuring the social performance of enterprises. The study also aimed to know how social auditing has an impact and its role in improving the social performance of business organizations, and the research refers to testing the hypotheses of an impact of social auditing on social performance through a commitment to social responsibility. The research sample consisted of 200 individuals from 20 Algerian business organizations and represented individuals who were researched in managers and em

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Publication Date
Wed Oct 18 2023
Journal Name
Iraqi National Journal Of Nursing Specialties
The Effect of a Training Program on the Diabetic Patients Utilizing Skills of Insulin Injection Technique
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Objectives: The study aims to evaluate patients’ performance toward insulin injection after training program to
identify the variation in skill of patients in insulin injection technique with regard to some variable (i.e.
educational level and duration of insulin injection.
Methodology: A quasi experimental study has been conducted on diabetic patients.
An observational checklist had been prepared which consisted of 4 main areas with 37 sub-items, which are
syringe preparation for injection, insulin drawing; skin preparation for injection and insulin injection. Each of the
sub-items has 2 options yes or no. One score for positive answer and zero for no.
The sample of the study consisted of (n =30) males and females

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Publication Date
Tue Jul 14 2015
Journal Name
Ibn Al-haitham J. For Pure & Appl. Sci.
Effect of Annealing Temperature and Thickness on the Structural and Optical Properties of CdSeThin Films
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CdSe alloy has been prepared successfully from its high purity elements. Thin films of this alloy with different thicknesses (300,700)nm have been grown on glass substrates at room temperature under very low pressure (10-5)Torr with rate of deposition (1.7)nm/sec by thermal evaporation technique, after that these thin films have been heat treated under low pressure (10-2)Torr at (473,673)K for one hour. X-ray patterns showed that both CdSe alloy and thin films are polycrystalline and have the hexagonal structure with preferential orientation in the [100] and [002] direction respectively. The optical measurements indicated that CdSe thin films have allowed direct optical energy band gap, and it increases from (1.77- 1.84) eV and from

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Publication Date
Fri Jan 01 2016
Journal Name
Middle-east Journal Of Scientific Research
Question Classification Using Different Approach: A Whole Review
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Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
The role of MIS in the negotiation process "An Analytical Study in a Sample of Iraqi Organizations"
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Negotiation is considered as one of the most important kinds of communication in the contemporary organizations, which depend on the important role of managerial information systems in providing necessary and suitable information for success of the negotiation process.

Accordingly, this study aims at measuring the extent of the variables effect of managerial information system in the negotiation process.

To achieve this study, two hypotheses were chosen; the first is the correlation relation and the second is the effect, and statistical means represented by correlation coefficient "Spearman" and (R2) were used.

 A Number of conclusions were

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Publication Date
Tue Oct 01 2024
Journal Name
Journal Of Physics: Conference Series
An Effect of Al on the Properties of ZnIn<sub>2</sub>Se<sub>4</sub> Thin Film
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Abstract<p>Zinc-indium-selenide ZnIn<sub>2</sub>Se<sub>4</sub> (ZIS) ternary chalcopyrite thin film on glass with a 500 nm thickness was fabricated by using the thermal evaporation system with a pressure of approximately 2.5×10<sup>−5</sup> mbar and a deposition rate of 12 Å/s. The effect of aluminum (Al) doping with 0.02 and 0.04 ratios on the structural and optical properties of film was examined. The utilization of X-ray diffraction (XRD) was employed to showcase the influence of aluminum doping on structural properties. XRD shows that thin ZIS-pure, Al-doped films at RT are polycrystalline with tetragonal structure and preferred (112) orientation. Where the </p> ... Show More
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Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Influence of Organizational Power on the Achievement of Entrepreneurship for Business Organizations An Analytical Study of the Views of a Sample of Managers in the Iraqi Ministry of Education
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This research aims to study the influence of organizational power on the achievement of entrepreneurship for business organizations. It is an analytical study of the views of a sample of managers in the Iraqi Ministry of Education. The research highlights the contribution that can be made from the knowledge of the theory of business organizations in achieving organizational success. The organizational power of the organization contributes to achieving entrepreneurship in the business environment and achieving a competitive position in the work environment. The research dealt with two variables: the first is the independent variable, the organizational power in its dimensions (Expend Power, Structural Power, Prestige Power). And t

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