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Assessment of using different ozone-friendly R22 alternative refrigerants in residential air conditioners in a high-ambient temperature country
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Abstract<p>The performance of a vapor compression refrigeration system (VCRS)-based residential air conditioner operating in a high-ambient temperature (HAT) country was investigated using six zero-ODP (ozone depletion potential) refrigerants as replacements to R22. The non-flammable alternative refrigerants considered in the present research were R134a, R404A, R407C, R410A, R448A, and R507A. Using the basic conservation laws, the VCRS was modeled during steady-state operation and solved using engineering equation solver (EES) software. Coefficient of performance (COP), pressures and temperatures at compressor suction and discharge, Global Warming Potential (GWP), critical pressure and temperature, compressor pressure ratio, volumetric cooling capacity (VCC) specific cooling capacity (SCC), and refrigeration effect were utilized as assessment criteria for the alternative refrigerants considered. From these refrigerants, the highest values of suction pressure, discharge temperature, and condenser pressure were attained by R410A. In addition, the discharge temperatures for all refrigerants, except R134a, were all higher than their corresponding critical values, causing a quicker drop in the VCRS’s performance. As an alternative refrigerant, R407C showed the highest SCC of 141.0 kJ/kg followed directly by 139.2 and 138.0 kJ/kg for R410A and R448A, respectively. A reverse trend was found for VCC with respective values of 4722 and 3775 kJ/m<sup>3</sup> for R410A and R448A. Lower volume flow rates and smaller-sized compressors are expected for higher VCC refrigerants. The same trend was found for the compressor’s specific work input and condenser’s specific heat transfer with values of (51.14, 46.82, and 45.38 kJ/kg) and (190.3, 187.8, and 183.4 kJ/kg) for R410A, R407C, and R448A, respectively. For applications in HAT countries, larger condenser’s specific heat transfer makes the refrigerant more applicable. Conversely, with respect to COP, refrigerant R134a with a value of 3.075 was the superior alternative followed by R448A and R407C with respective COPs of 3.042 and 3.011. Based on the overall assessment in terms of environmental obligation, COP, compressor input power, refrigerant flow rate required, and all the evaluations made in this research, refrigerant R448A was recommended as the most appropriate substitute to R22 which can effectively be used in residential air conditioners in a HAT country.</p>
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Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
X-ray Data and Transition Temperature Measurements of Ca Doped Bi2Sr2La2Cu3O10+δ Superconductor
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We studied the effect of Ca- doping on the properties of Bi-based superconductors by
adding differ ent amounts of CaO
to the Bi
2
Sr2La2-xCaxCu3O10+δ
compound. consequently, we
obtained three samples A,B and C with x=0.0, 0.4 and 0.8 respectively. The usual solid-state
reaction method has been applied under optimum conditions. The x-ray diffraction analy sis
showed that the samples A and B have tetragonal structures conversely the sample C has an
orthorhombic structure. In addition XRD analysis show that decreasing the c-axis lattice
constant and thus decreasing the ratio c/a for samples A,B and C resp ectively. The X-ray
florescence proved that the compositions of samples A,B and C with the ra

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
STUDY OF TEMPERATURE EFFECT ON THE HARDNESS FOR EPOXY RESIN AND UNSATURATED POLYESTER
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This search aim to measure Hardness for Epoxy resin and for unsaturated Polyester resin as base materials for composite Hybrid and the materials used is Hybrid fiber Carbon-Kevlar. The Hand Lay-up method was used to manufacture plates of Epoxy resin (EP) and unsaturated Polyester EP,UPE backed by Hybrid fiber (Carbon-Kevlar) and with small volume fraction 5,10 and 15 for every there are Layer of fibers (1,2 and 3). The hardness test was count for material EP, UPE resin and there composites and that we notice that the Hardness (HB) decreased with increase of temperatures.

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Publication Date
Wed May 01 2019
Journal Name
Optik
Ag2S/ZnO Nanorods Composite Photoelectrode Prepared by Hydrothermal Method: Influence of Growth Temperature
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Publication Date
Sun Dec 01 2002
Journal Name
Iraqi Journal Of Physics
Dependence of the Hall Mobility and Carrier Concentration on Thickness and Annealing Temperature
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Hall effect measurements have been made on a-As2Te3 thin films different thickness film in the range (200-350) nm. The Hall mobility in a-As2Te3 thin films decreases with increasing annealing temperature but the carrier concentration increases. When increasing the film thickness increases the Hall mobility decreases, while the carrier concentration increases.

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Publication Date
Wed Jan 01 2020
Journal Name
Iraqi National Journal Of Nursing Specialties
Assessment of Nurses knowledge toward prevention of Complications related Valvular Replacement Surgery at Surgical Department in AL-Nasiriyah Heart Center
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Objectives: The study aims to assess  the nurses knowledge toward prevention of complications related to valvular  replacement surgery and to find out the relationship between nurses knowledge and their demographic and occupational characteristic's Which as (Age, gender, level of education ,years of experience in Surgical Department , and training sessions)

 

Methodology: A descriptive design  (a cross-sectional study ) was carried out from December 2017 to May 2018 in order to assess nurses' knowledge of preventing complications Valvular Replacement Surgery at Surgical Department in  Nasiriyah Heart Center on a purposive (non-probability) sample

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Publication Date
Sat Jun 30 2012
Journal Name
Al-kindy College Medical Journal
Assessment of Neck Circumference Measurement among Type 2 Diabetic Patients in Identifying: Obesity and the Likelihood of Developing Metabolic syndrome.
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Background: Obesity is an evolving major health problem in both developed and developing countries. Traditional obesity indices as body mass index, waist circumference, waist-hip-ratio are well known measures to identify obese subjects, however, neck circumference as an index of upper-body obesity was found to be a simple and time-saving screening measure that can be used to identify obesity and the likelihood of developing metabolic syndrome in type 2 diabetic patients.
Aim: to investigate the relationship of neck circumference (NC) to obesity and metabolic syndrome in Iraqi subjects with type 2 diabetes.
Methods: The study group included 90 type 2 diabetic subjects (48 men and 42 women) aged 30-68 years. The subjects were those w

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Publication Date
Wed Jun 19 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Impact of Self-Assessment on Income and Sale Tax Collection' From the Point View of Income Tax Auditors in Jordan
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This study aimed to show the extent of compliance with the income taxpayer  to provide tax returns and increase the speed of collection of these taxes in addition to increasing confidence in  Income Tax department and reduce the number of cases transferred to the courts and promote taxpayer awareness in charge of the importance of self-assessment system, and study sought to investigate the effect of the existence of records documents, technical audit, and computational audit and documentary audit on income tax collections in Jordan, from the point of viewof Jordanian income tax auditors ,results shows there's a strong  relation between these variables and Income Tax collections.

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Publication Date
Thu Feb 29 2024
Journal Name
International Journal Of Design &amp; Nature And Ecodynamics
Artificial Neural Network Assessment of Groundwater Quality for Agricultural Use in Babylon City: An Evaluation of Salinity and Ionic Composition
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Publication Date
Sat Jan 31 2009
Journal Name
Not Published
Assessment of the pediatric nurse's knowledge about the nosocomial infection in neonatal intensive care unit of Baghdad pediatric teaching hospitals
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Publication Date
Thu Mar 01 2018
Journal Name
International Journal Of Oral And Maxillofacial Surgery
Assessment of facial asymmetry before and after the surgical repair of cleft lip in unilateral cleft lip and palate cases
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