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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
Tue Feb 01 2022
Journal Name
Journal Of Engineering
Evaluation and Development of the (Hilla – Daghara) Rivers System
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Shatt Al-Hilla branches from the left of Euphrates River, U/S Hindiyah Barrage, Iraq, and extends about 100 km. It branches at the end into Shatt Al-Diwaniya 112 km and Shatt Al-Daghara 64 km. The study aims to evaluate and develop (Hilla-Daghara) rivers system, which is included Shatt Al-Hilla and Shatt Al-Daghara. Fieldwork began from (26 October until December) 2020. M9, S5 devices, and the installed staff gauges were used to measure discharges and water levels, respectively. A one-dimensional model was developed for the study area by HEC-RAS, after calibration and verification by field measurements; the Manning's n of Shatt Al-Daghara is found to be 0.022. Five Scenarios were simulated to study the reach under the cu

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Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Investigate the effectiveness of investment in the electricity sector And its role in achieving sustainable development
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The provision of electric power is necessary for the advancement of the country's economy. It is the main engine of the economy and its various activities. It is an indicator of social welfare and it is considered as the basic pillars for achieving sustainable development (economic, social, environmental and institutional) by raising the levels of performance and meeting local needs. The problem of research was the absence of a program to audit the performance of the electricity sector contributes to ensure the application of sustainable development. The research was based on the hypothesis that the preparation of a proposed program to audit the performance of the electricity sector contributes to the achievement of The researchers sough

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Publication Date
Sat Mar 02 2024
Journal Name
International Development Planning Review
EXTRAPOLATION OF THE MACHINE AND ITS EFFICIENCY IN DEVELOPING THE SKILL PERFORMANCE AND ACCURACY OF DRIBBLING IN YOUTH FOOTBALL
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Relying on modern work strategies, such as adopting scientific inductions, consolidates the information in the learner’s memory, develops the skill work of the football player, and raises the efficiency of their motor abilities. From this standpoint, the researcher, who is a teacher at the University of Baghdad, College of Physical Education and Sports Sciences, and follows most of the sports club teams in youth football, believes that there must be From extrapolations through the machine and employing it in the field to serve the skill aspect and benefit from scientific technology in development and making it a useful tool to serve the sports field in football, as the goal of the research was the efficiency of machine extrapolation in de

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Publication Date
Tue Nov 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Environmental awareness in the curriculum and its role in sustainable environmental planning
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                The goal of current research to the definition of environmental awareness in the curriculum and its role in sustainable environmental planning, was the research community official regular educational schools (kindergarten, primary, secondary) for the province of Baghdad - Iraq, the sample consisted search of (100) teacher and a teacher, and what research was descriptive analytical, researchers have selected the right tool for the research procedures (closed) questionnaire, distributed to the research sample, has been used by researchers appropriate statistical methods for procedures including: the weighted average extraction unit paragraph,

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Publication Date
Sun Dec 10 2017
Journal Name
Al-academy
Undermining Humanism in Foucault's mind and its implications in the pop art
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The following research has been dealing ( Undermining Humanism in Foucault's thought and its implications in the pop art. meanings and facts which become in the process of the post-modernist.So the research's problem is to ask for undermining Humanism in Foucault's thought and how it formed through the formality of processors and the technical and stylistic and contents in pop art.. How are these technical aspects interact with each other to undermine the humanism in Foucault's mind and with system humanity, intellectual and social relations in the post-modern society . The contents of the first chapter, is the aim of the research, which aims to undermine know humanism in Foucault's mind and its implications in pop art , within the limit

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Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Assessment of Human Investment Efficiency in the Private University Teaching according to the strategy of Higher Education in Iraq and chosen Colleges))
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Abstract:

the current research aims at analyzing the efficiency of the private university teaching  that recently expanded after 2003 ,;besides , the commitment of the private colleges ,definitely Al-Maamun and Al-Mansour colleges with strategy  of the ministry of higher  education and scientific  research.  This could be done through many indications that measure the efficiency of the  private university teaching , including ( the indication of  the efficiency of   using human resources and efficiency  in using  the materialistic indications.  But the human efficiency in these colleges , including the sample  of the research ( Maamun 

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Publication Date
Sat Dec 04 2021
Journal Name
International Journal Of Drug Delivery Technology
Evaluation of the Anti-inflammatory and Anti-oxidant Activity of Crab Components and Crab Shell in Experimental Rats in Comparison with Dexamethasone and Diclofenac Sodium
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Crabs belong to the crustacean family (Decapods crustacean), and their shells contain natural ingredients from which the bioactive compounds are derived. It has been used as folklore medicine in cancer treatment. We investigate the possible anti-inflammatory and anti-oxidant effects for crab shells and whole crabs. Thirty-six rats (150–200 gm) from both sexes were used, divided into six groups, the anti-inflammatory and anti-oxidant activity measured using cotton pellet induce granuloma model. Detection of tumor necrosis factor alpha (TNF α), Interleukin 1 beta (IL-1β), superoxide (SOD), and malondialdehyde (MDA) levels using ELISA Kits. The data analysis by one-way ANOVA followed by the Tukey test. Values are significant at (p < 0.05).

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Publication Date
Wed Feb 20 2019
Journal Name
Political Sciences Journal
The status of the state and its relationship to the concept of force in international relations
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The concept of power despite its implications unclear and unknown was one of the most standards in international relations ambiguity and lack of clarity, however was more standards important and influential in the conduct of international relations, and since that time until today since that ambiguity in the meaning of power and use it as a factor of international relations factors and drive the engines were very different and irony from case to case and from researcher to another, but it may be classified force as the international status enjoyed by the state in the international ocean and here is a structure formed of forces posed by the state, such as economic and political nature of the political system and military power and concept

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Publication Date
Sat Feb 14 2026
Journal Name
Al-academy
Hijab and Burqa in Islamic Fashion System
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Publication Date
Sat Feb 14 2026
Journal Name
Journal Of Baghdad College Of Dentistry
An Evaluation of the Solubility of Four Endodontic Sealers in Different Solvents (An In Vitro Study)
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Background: Complete removal of filling material from the root canal is an essential requirement for endodontic retreatment. The purpose of the present study is to evaluate and compare the dissolving capabilities of various solvents (Xylene, Eugenate Desobturator, Eucalyptol, EDTA and Distilled water (as a control)) on four different types of sealer (Endofill, Apexit Plus, AH Plus and EndoSequence bioceramic sealer). Materials and method: Eighty samples of each sealer were prepared according to the manufacturers' instructions and then divided into ten groups (of 8 samples) for immersion in the respective solvents for 2 and 5 min immersion periods. Each sealer specimen was weighed to obtain its initial mass. The specimens were immersed in

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