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The Experimental Assessment of R134a and Its Lower GWP Alternative R1234yf in an Automobile Air Conditioning System
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Reducing global warming potential (GWP) of refrigerants is needed to the decrease of ozone-depleting of refrigeration systems leakages. Refrigerant R1234yf is now used to substitute R134a inside mobile air conditioning systems. Thermodynamic properties of R1234yf are similar to R134a. Also, it has a very low GWP of 4, compared to 1430 for R134a, making it a proper choice for future automobile refrigerants. The purpose of this research is to represent the main operating and performance differences between R1234yf and R134a. Experimental analysis was carried out on the automotive air conditioning system (AACS) with 3 kW nominal capacity, to test and compare the performance of R134a with R1234yf. Experiments were accomplished for both refrigerants in almost the same working conditions and procedure with a range of ambient temperature varied from 26oC to 50oC. Parameters studied were ambient temperature, type of refrigerant in the system at compressor speed 1450 rpm, and internal thermal loads of passenger room. The performance characteristics of the system, including COP and cooling capacity, were studied by changing different parameters. The results show that COP of R134a is higher than R1234yf by 12.6%, while the refrigeration effect of R134a is higher than R1234yf by 25%. This shows that R1234yf is a suitable and good candidate for drop-in replacement of R134a in AACS.

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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Engineering
A Mathematical Model of a Thermally Activated Roof (TAR) Cooling System Using a Simplified RC-Thermal Model with Time Dependent Supply Water Temperature
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This paper presents a computer simulation model of a thermally activated roof (TAR) to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model) for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time

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Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
Adultery in the Ancient near east from the standpoint of the customs and traditions and the old laws
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Publication Date
Wed Jun 19 2019
Journal Name
Biochemical And Cellular Archives
SYNTHESIS, CHARACTERIZATION, STRUCTURAL, THERMAL, POM STUDIES, ANTIMICROBIAL AND DNA CLEAVAGE ACTIVITY OF A NEW SCHIFF BASE-AZO LIGAND AND ITS COMPLEXATION WITH SELECTED METAL IONS
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SYNTHESIS, CHARACTERIZATION, STRUCTURAL, THERMAL, POM STUDIES, ANTIMICROBIAL AND DNA CLEAVAGE ACTIVITY OF A NEW SCHIFF BASE-AZO LIGAND AND ITS COMPLEXATION WITH SELECTED METAL IONS

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Scopus
Publication Date
Tue Feb 17 2026
Journal Name
Revista Iberoamericana De Psicología Del Ejercicio Y El Deporte, Issn 1886-8576, Vol. 18, Nº. 1, 2023, Págs. 19-29
Constructing A Measure of Psychological Disability and Its Relationship to Some Basic Skills and Fixed Playing Situations for Youth Football Players Under (19) Years Old
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Autorías: Muwafaq Obayes Khudhair, Sanaa Rabeea Abed, Hayder Talib Jasim. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 1, 2023. Artículo de Revista en Dialnet.

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Publication Date
Wed Apr 30 2025
Journal Name
Samarra Journal Of Pure And Applied Science
Synthesis, Spectral Characterization and Biological Activity of Schiff Base ligand Derived from 5-amino-2-phenyl-2,4-dihydro3H-Pyrazol-3-one and its Metal Complexes
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Eight new complexes with the general formula [M(L)2(H2O)2] were prepared resulting from the reaction of the new Schiff base ligand [(E)-5- ((2-hydroxybenzylidene)amino)-2-phenyl-2,4-dihydro-3H-pyrazol-3- one(L)] with metal ions [manganese, cadmium, zinc, copper, nickel, cobalt, Mercury Bivalent and tetravalent platinum. This ligand was derived from the reaction of the amine (5-amino-2-phenyl-2,4-dihydro3H-pyrazol-3-one) with Salicylaldehyde, which is linked to the metal ions via two atoms. The nitrogen is the isomethene group, and the oxygen is the hydroxide group of the pyrazoline ring. The prepared compounds were characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy, and ultraviolet spectroscopy, and from the

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Publication Date
Tue Nov 13 2018
Journal Name
Biochemical And Cellular Archives
Synthesis, characterization, structural, thermal, POM, studies, antimicrobial, and DNA cleavage activity of a new schiff base-azo lighand and its complexation with selected metal ions
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RKRAS L. K. Abdul Karem, F. H. Ganim, Biochemical and Cellular Archives, 2018 - Cited by 2

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Publication Date
Sun Jan 01 2023
Journal Name
2nd International Conference Of Mathematics, Applied Sciences, Information And Communication Technology
Spatial and temporal analysis of the spread of Covid-19 in Iraq
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Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The role of Open Budget in achieving of the transparency and responsibility and Reflect it on the administrative and financial corruption
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Abstract

The open budget means everyone in the society can get information about the government budget in order to watch the governmental works. The aim of the research is to study the concepts of open budget, its advantage, limitations, role of supporting the transparency and questioning the administrative and financial corruption. Thus reflects positively on the national economy by providing governmental information to all users whether they are individuals or belong to the political class, or any other governmental or nongovernmental organizations which are interested in these information.

In order to achieve the objectives of the research aims, we make questionnaire to see aca

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Publication Date
Mon Jan 01 2024
Journal Name
Open Agriculture
Interannual variations of normalized difference vegetation index and potential evapotranspiration and their relationship in the Baghdad area
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Abstract<p>A monthly correlation between urban vegetation growth and potential evapotranspiration (PET) is needed for better knowledge of controlling water resources and organized irrigation processes. This study aims to explore their relationship within an urban area like Baghdad, using a linear regression model to derive a best-fit line drawn in a scatterplot on a monthly time scale. Based on two different monthly data sources: weather variables (e.g., air temperature, solar radiation, and relative humidity) and Sentinel-2 satellite imagery of 2 years, 2018 and 2021, this study presented the interannual variations of PET and normalized difference vegetation index (NDVI). The choice of these ye</p> ... Show More
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Publication Date
Sun Dec 31 2023
Journal Name
College Of Islamic Sciences
The most prominent philosophical and rhetorical concepts in the perspective of philosophers and theologians
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     This research aims to clarify and define the most important philosophical and rhetorical concepts to which many philosophical and rhetorical issues refer، since they have an effective role in the diversity and difference of intellectual schools، which are indispensable in proving major dogmatic issues، such as the concept of (existence، being، essence، and authenticity). Existence or Essence in contrast to the consideration of the other concept)، because it is one of the complex concepts and common words that carry different connotations among thinkers.

   And from (the rule of judging something is a branch of its perception)، the researchers began to define these concepts، as evidence of the sincerity of perce

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