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Exergy Analysis of a Domestic Refrigerator
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An energy and exergy thermodynamic analysis using EES program was done for a domestic refrigerator working with R-134a using vapor compression refrigeration cycle. The analysis deals with the system component, i.e. compressor, condenser, evaporator and the expansion device. The analysis depends on the entropy generation minimization approach to improve the refrigerator performance by exploring the optimum design points. These design points were derived from three different theories governing the entropy generation minimization using exergy analyzing method. These theories were first applied to find the optimum balance between the hot inner condenser area and the cold inner evaporator area of the refrigerator and between its hot and cold thermal conductances. Nine types of condensers were used according to its internal surface area and thermal conductance, in order to reach the minimum entropy generation in the refrigerator. The results showed that the compressor has the lowest exergy efficiency of 25%. The expansion device was the second component after the compressor with exergy efficiency of 92%, followed by the condenser with an efficiency of 93%. The evaporator was found to have an exergy efficiency of 98 %. The experimental tests were repeated for the nine condensers sizes with three different ambient temperatures 25℃, 30℃ and 35℃.  The exergy analysis showed that the design of the refrigerator mainly depends on thermal conductance calculations rather than the surface inner area estimation.

 

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Publication Date
Mon Jun 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Economic Implications of Economic Corruption
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There are  many  economic issues that  concern society at the local and international levels and which constitute  a serious  challenge to the societies  and governments , perhaps  including  the issue of corruption  in all its  forms and manifestations and effects , which  now attract the attention  the issue of human society everywhere .                                                      

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Publication Date
Sun Sep 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Hydrotreating of Sharki Baghdad Residue
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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The economic importance of nanotechnology
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Abstract

Toady technology Nano since it launched human Alivia third interest and anticipation unusual and that by the decision-makers in the world's governments and its institutions and research departments productivity, especially after the US Congress enact a law (the National Initiative for Tknlojba nanotechnology in the United States of America) and the allocation of large sums of money To support this initiative, the research aims to shed light on the concept of technology nanotechnology, which is technology atheist and the twentieth century, and reflect its economic importance and in order to reach the objectives of the research has been the division of research into several axes has been allocated

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Publication Date
Sun Aug 01 2021
Journal Name
Journal Of Engineering
Flood Management of Diyala River
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Diyala Governorate was recently exposed to high flood waves discharged from Hemrin Dam. Since the dam was at its full capacity during the flood period, these waves were discharged to the Diyala River. Because of the reduction in Diyala River capacity to 750m3/s, the cities and villages on both sides of the river banks were inundated. Thus, the study's objective is to design a flood escape out of the Diyala River, to discharge the flood wave through it. The flood escape simulation was done by using HEC- RAS software. Two hundred twenty-three cross sections for the escape and 30 cross-sections of the Diyala River were used as geometric data. Depending on the geological formation that the escape passed t

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Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
ADSORPTION STUDY OF HYDRODESULPHURIZATION CATALYST
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Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K
and hydrogen gas using volumetric apparatus at room temperature respectively. These analyses were used for
determination the effect of coke deposition and poisoning metal on surface area, pore size distribution and
metal surface area of fresh and spent hydrodesulphurization catalyst Co-Mo\Al2O3 .
Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery.
The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with
fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores
of these sample

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Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Engineering
Characteristics of Paper-cement Composite
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This study “discusses the benefit of “addition waste paper as a “new cellulose material “in mortar mixes. A partial addition of waste paper by cement weight was achieved to produce cement composite mortar.  Pulp and paper is the third major industrial dumper of air, soil and water. In recent year, paper and paperboard constitute a greater portion of many countries’ urban solid discarded generation. Beside, it increases characteristic “strength due to existence “of hydrogen links “in the microstructure of “paper. Furthermore, it consume “better thermal protection. The addition percentages “of waste paper used “in this work were (5%, 10%, 15% and 20%) by “mass of cement to measure and evaluat

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Publication Date
Tue Nov 03 2020
Journal Name
Modern Sport
The requirements of sustainable development for colleges of physical education and sports science in Iraq
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l development in addition to environmental reform, which is not possible at its best, and from this the faculties of physical education and sports science realize the scale of the problem and its importance in the development of society that this all puts on the faculties of education Physical and sports sciences are a very difficult task and an end in holiness, for it is the responsibility of the human development service and its leadership, because the community leaders and its elites are those who value their direction and future more than others. The importance of this study comes from the goal of sustainable development to maximizing pain. The net gain from higher education while ensuring the preservation of the quality of reso

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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Study of annealing effect on some Optical Properties of CuIn(SexTe1-x)2 Thin Films
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The optical properties for the components CuIn(SexTe1-x)2 thin films with both values of selenium content (x) [0.4 and 0.6] are studied. The films have been prepared by the vacuum thermal evaporation method with thickness of (250±5nm) on glass substrates. From the transmittance and absorbance spectra within the range of wavelength (400-900)nm, we determined the forbidden optical energy gap (Egopt) and the constant (B). From the studyingthe relation between absorption coefficient (α) photon energy, we determined the tails width inside the energy gap.
The results showed that the optical transition is direct; we also found that the optical energy gap increases with annealing temperature and selenium content (x). However, the width of l

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Radon concentration measurements in sludge of oil fields in North Oil Company (N.O.C.) of Iraq
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In this study the assessment radon concentration in sludge of Oil
Fields in North Oil Company (N.O.C.) of Iraq have been studied
using CR-39 solid–state nuclear track detector technique. A total of
34 samples selected from 12 oil stations in the company have been
placed in the dosimeters. The average radon concentration was found
to be 162.29 Bq/m3 which is fortunately lower than the standard
international limit. The potential alpha energy concentration and
annual effective dose have been calculated. A proportional
relationship between the annual effective dose and radon
concentration within the studied region has been certified.

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Publication Date
Mon Jan 01 2018
Journal Name
Biochemical And Cellular Archives
Optimization of enzymatic conversion of waste office paper using response surface methodology for bioethanol production
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