Preferred Language
Articles
/
YBim3JYBVTCNdQwCuoek
Assessment of using different ozone-friendly R22 alternative refrigerants in residential air conditioners in a high-ambient temperature country
...Show More Authors
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>
Scopus Crossref
View Publication
Publication Date
Thu Aug 01 2024
Journal Name
Journal Of Engineering Research
Design, analysis and development of a proton exchange membrane in fuel cell
...Show More Authors

View Publication
Scopus (4)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Corporate And Business Strategy Review
The role of learning organizations in crisis management strategy: A case study
...Show More Authors

The problem of the paper focused on the role of the learning organization in the crisis management strategy, and the extent of the actual interest in both the learning organization and the crisis management and aimed at diagnosing and analyzing that and surrounding questions. The Statistical Package for the Social Sciences (SPSS) program was used to calculate the results and the correlation coefficient between the two main variables. The methodology was descriptive and analytical. The case study was followed by a questionnaire that was distributed to a sample of 31 teachers. The paper adopted a seven-dimensional model of systemic thinking that encourages questioning, empowerment, provision of advanced technologies, and strategic lea

... Show More
View Publication
Scopus (15)
Crossref (9)
Scopus Crossref
Publication Date
Thu Mar 10 2022
Journal Name
Oral Surgery
Evaluation of buffered local anaesthesia in dental extraction: A randomized controlled study
...Show More Authors

Buffering of Local anaesthesia (LA) has been suggested as a mechanism to improve injection comfort and hasten the onset of anaesthesia. Aim This study aimed to evaluate the effectiveness of buffered LA in the extraction of maxillary premolars and molars. Materials and Methods This randomized controlled study included 100 patients who were indicated for extraction of maxillary posterior teeth, they were randomly divided into two groups; a study group that received infiltration of buffered 2% lidocaine hydrochloride with 1:80,000 epinephrine LA, and a control group that received non-buffered 2% lidocaine hydrochloride with 1:80,000 epinephrine LA. The buffering was performed using the Onset® LA buffering system (Onpharma®). The outcome va

... Show More
View Publication
Scopus (6)
Crossref (3)
Scopus Crossref
Publication Date
Wed May 11 2022
Journal Name
Journal Of Economics And Administrative Sciences
Comparing Some Methods For A single Imputed A missing Observation In Estimating Nonparametric Regression Function
...Show More Authors

In this paper, we will study non parametric model when the response variable have missing data (non response) in observations it under missing mechanisms MCAR, then we suggest Kernel-Based Non-Parametric Single-Imputation instead of missing value and compare it with Nearest Neighbor Imputation by using the simulation about some difference models and with difference cases as the sample size, variance and rate of missing data.      

View Publication Preview PDF
Crossref
Publication Date
Wed Jan 01 2020
Journal Name
2nd International Conference On Materials Engineering &amp; Science (iconmeas 2019)
A kinetic model for prodigiosin production by Serratia marcescens as a bio-colorant in bioreactor
...Show More Authors

View Publication
Scopus (19)
Crossref (20)
Scopus Crossref
Publication Date
Wed Sep 15 2021
Journal Name
Arab World English Journal
How Impoliteness Is Portrayed in a School Context: The Marva Collins as a Case Study
...Show More Authors

The present study attempts to examine verbal/nonverbal impoliteness in the classroom interaction and outside it in one of the movies, namely, The Marva Collins. Impoliteness, which is significantly studied within pragmatics, is a negative attitude towards particular behaviors. It always presumes to have emotional concerns for at least one participant who has caused it. This study is an attempt to examine verbal/nonverbal impoliteness in The Marva Collins movie. The study aims to investigate the different types of impoliteness strategies used in the four selected scenes and find out whether the speaker’s status has anything to do with the types of impoliteness. Besides, the functions performed are also examined by following a qual

... Show More
View Publication Preview PDF
Crossref (2)
Clarivate Crossref
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The role of academic leadership practices in activating the human capital / A field research of a Iraqi universities sample / Baghdad
...Show More Authors

The aims of this study to diagnose the role of the (relationship and impact) Academic driving practices dimensions (model the way, inspire a shared vision, challenge the process, enable others to act, encourage the heart ) in the activation of human capital (investment and development) for (knowledge, skills, expertise, creative and training capabilities) in a sample of university professors in Baghdad city(Baghdad University, Al Mustansiriya University, University of Technology). (367 )samples were distributed to (232 at the University of Baghdad, 97 at Al-Mustansiriya University and 38 at the University of Technology). The goals of descriptive analytical method research have been used, questionnaire has been a main tool for dat

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Plant Archives J.
Evaluation of the performance of introduced varieties of maize under different planting dates and environments
...Show More Authors

Scopus (3)
Scopus
Publication Date
Thu Jun 09 2022
Journal Name
2022 International Congress On Human-computer Interaction, Optimization And Robotic Applications (hora)
Study of Inelastic Coulomb Form Factors in 18O using the Radial Wave functions of Transformed Harmonic-Oscillator
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Wed Dec 27 2023
Journal Name
Journal Of Planner And Development
Priorities for the reconstruction of religious buildings in the old city of Mosul using Expert Choice program
...Show More Authors

This paper attempts to shed light on the most influential factors in the importance of religious buildings were destroyed because of the recent war due to the control of terrorist gangs of ISIS over the city of Mosul, and to prioritize their reconstruction and their role in reviving the historical center of Mosul.

The research’s problem emerged in the lack of knowledge about the identifying the most influential factors in the importance of religious buildings and utilizing them to prioritize their reconstruction. This study aims to analyze the factors influencing the importance of religious buildings using the Expert Choice software through the Analytic Hierarchy Process (AHP) to reach an analysis of their weights and propose p

... Show More
View Publication Preview PDF