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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
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
Critical Thinking Skills of A’Sharqiah University Students According to California Critical Thinking Skills Test and Its Relationship to Some Variables
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Abstract

The research aims to measure the level of critical thinking skills among students of A’Sharqiah University in the Sultanate of Oman, as well as identify the level of their availability based on the variables: gender, academic level, school year, cumulative average, and general diploma / high school ratio. The researchers used the descriptive approach. To achieve the objectives of the study, they used The California Test for Critical Thinking Skills Picture (A) after evaluation (Farraj, 2006). It was applied to a sample of (487) students from A’sharqiah University. The results of the study found that the critical thinking skills of A’sharqiah University students are below the educationally acceptabl

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Publication Date
Wed Jun 29 2022
Journal Name
College Of Islamic Sciences
Evidence for monotheism in Islam and the Qur’an and the meaning of the names and attributes and their unification
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This topic is considered to be of a high degree of importance to every Muslim, and its importance is due to the fact that monotheism is:

Prove that God Almighty is the God who created everything and everything opposite to monotheism is polytheism, and it is taking other than God Almighty as a deity.

Therefore, we have to know the concept of God. If he is known, then he knows the concept of monotheism and the concept of polytheism

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Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Assets Valuation Approaches & its Reflects on Financial Reporting Quality
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Abstract

   The model of financial reporting in  Iraq  Based on a specific set of accounting objectives & concepts, which require the application of the historical cost valuation approach due to the nature of the objectives of financial reporting in Iraq, established under the unified accounting system , which focuses on serving the needs of the state because it the most influential user in setting accounting objectives and concepts, which stems mainly from the nature of the economic system in Iraq, which focuses on the public sector versus the private sector as well as the nature of the ownership business that focuses on partnership versus corpor

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Publication Date
Sun Apr 03 2016
Journal Name
Journal Of Educational And Psychological Researches
Egocentrism & its Relationship with Academic Adaptation among University students
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The research aimed to identifying :

  1. Egocentrism of the university students .
  2. Academic adaptation of the university student.
  3. Differences in Egocentrism according to the both variable ( Gender and Specialization ) of the university student.
  4. Differences in academic adaptation according to the both variable ( Gender and Specialization ) of the university student .
  5. The Contribution of academic adaptation to Egocentrism of the university student .

The sample of the research consisted of ( 400 ) students.      
Tow instruments have been us

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Publication Date
Thu May 01 2025
Journal Name
Dirasat: Human And Social Sciences
The Role of Russian Writers and Intellectuals in the 1905 Revolution in Russia
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Objectives: The main objective of this study is to examine the crucial role that Russian writers and intellectuals played in catalyzing the 1905 Revolution in Russia. Specifically, the study sought to analyze how their literary works, philosophical ideas, and political writings challenged Tsarist autocracy, depicted the suffering of the masses, and inspired opposition movements. The study aimed to highlight the defiant writings that contributed to the rise of political figures and the eventual overthrow of the repressive regime. Methods: The historical narrative and analytical methods were employed, conducting a comparative analysis of prominent works by renowned authors such as Tolstoy, Gorky, and Chekhov. This analysis focused on

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Publication Date
Thu Jun 01 2023
Journal Name
جعفر الصادق
The Role of Criminal Policy in Iraq in Protecting and Improving the Environment
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Publication Date
Fri Jan 15 2021
Journal Name
Palarch's Journal Of Archaeology Of Egypt/egyptology
Belief and practice in the teaching of pronunciation in the Iraqi EFL context
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IH Abdul-Abbas, QJ Rashid, M RasimYounus, PalArch's Journal of Archaeology of Egypt/Egyptology, 2021 - Cited by 9

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Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
The phenomenon of building the act of the actor and the effect in the Quranic readings                          (Structural and semantic study)
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After this systematic presentation of the phenomenon of rotation of formulas, ie the construction of the verb and the verb, and the narrated narratives therein differed among the readers, it became clear to us how the difference was clear between reading and the other, and how readers have varied in their readings of the verb, As we have noted through our modest research that the phenomenon of building the verb for the actor and the effect have included the act of both past and present tense, and not limited to a specific time, and this difference in reading was not limited to a particular environment, but beyond To more than one environment This is evidenced by the readings of various readers from the environment of Kufa, Basra, Mecca,

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Publication Date
Wed Dec 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Gingival Marginal Leakage of Different Tooth Colored Materials Combination as an Intermediate Layer in Class II Composite Restoration (A Comparative In Vitro Study)
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Background: The aim of this in vitro study was to evaluate and compare the microleakage between Vertise Flow T M composite material and other conventional (Filtek Z250, riva light cure and SDR) composite materials when restoring CII mesial box only cavity at gingival margin through die penetration test Materials and methods: Forty maxillary first premolars were prepared with class II box design only cavities. Samples were divided into four groups of ten teeth according to material used: group I (FiltekZ250 only). Group II (SDR+FiltekZ250). Group III (Vertise Flow +FiltekZ250). Group IV (Riva light cure+ FiltekZ250). After 24 hrs. immersion in 2% in methylene blue, samples were sectioned and micro leakage was estimated. Results: None of the

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Publication Date
Mon Feb 16 2026
Journal Name
Al–bahith Al–a'alami
EMPLOYING TWITTER IN THE U.S. PRESIDENTIAL ELECTION CAMPAIGN IN 2016: U.S. PRESIDENTIAL CANDIDATE DONALD TRUMP’S TWEETS AS A “MODEL”: (A Research Drawn from a Master’s Thesis) (An Analytical Study)
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This study aimed to identify the employment of the social networking platform «Twitter» in the 2016 presidential campaign led by the Republican candidate, Donald Trump; and analyse his tweets through his personal account on «Twitter»  for the period from: 10/ 8/2016 to: 11/ 8/2016 which represents the last month of the election campaign.

The study belongs to the type of descriptive studies using the analytical method through an analysis index that includes sub-categories and other secondary categories. The research has adopted the ordinary unit of information material (tweet) as an analysis unit for this purpose.

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