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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
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
A novel online coupling of ion selective electrode with the flow injection system for the determination of vitamin B1
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A simple, fast, selective of a new flow injection analysis method coupled with potentiometric detection was used to determine vitamin B1 in pharmaceutical formulations via the prepared new selective membranes. Two electrodes were constructed for the determination of vitamin B1 based on the ion-pair vitamin B1-phosphotungestic acid (B1-PTA) in a poly (vinyl chloride) supported with a plasticized di-butyl phthalate (DBPH) and di-butyl phosphate (DBP). Applications of these ion selective electrodes for the determination of vitamin B1 in the pharmaceutical preparations for batch and flow injection systems were described. The ion selective membrane exhibited a near-Nernstian slope values 56.88 and 58.53 mV / decade, with the linear dy

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Publication Date
Wed Sep 29 2021
Journal Name
College Of Islamic Sciences
the purposes of belief The concept of the purposes of belief and its importance: The first requirement: the concept and the aim of contractual purposes, The second requirement: the importance of nodal purposes
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Abstract

This research deals with the definition of the concept of nodal purposes, And what is related to it, from its aim and importance, And for the purposes of the importance of Streptococcus In trying to understand the nodal truths For different minds, Especially with those who object to the introduction of belief in purposes studies, This research has two requirements:

 The first requirement: the concept and the aim of contractual purposes,It consists of two branches, The first is in the concept of nodal purposes, And it dealt with the definitions in terms of language and terminology And what we see is proportional to what aim

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Publication Date
Tue Sep 03 2024
Journal Name
African Journal Of Biomedical Research
Assessment of Solubility, Moisture Content, Water Absorption and Thickness of Bioplastic synthesized from Iraqi Amber Rice Husks
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Publication Date
Tue Apr 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Relationship between Emotional Intelligence and Decision Making Styles And their effect on Performance Excellence the university" An exploratory search for a sample of the administrative leaderships in the Mustansiriya University"
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   Addressed this research the impact of intelligence emotional dimensions of the main(self awareness, and self-management, and social awareness, and relationship management) in the performance excellence the university(performance optimization, and strategic development) this is by middling the styles decision making which are (rational and intuitive, and dependent, and spontaneous, and avoidant), and Go search of an intellectual dilemma raise fundamental questions revolve around the search was to answer those questions through a theoretical framework for search variables first and test models of the relationship and second through the impact six hypotheses President.The objective of the research to make sure the contr

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Publication Date
Thu Nov 08 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
An Epidemiological Approach of Hydrocephaly Parameters in Duhok Province
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Objective(s): This study was conducted to deal with the importance and effect of various variables which might
have influence in hydrocephaly occurrence.
Methodology: A retrospective design was performed and continued for 4 months. It included 89 nonrandomized
consecutive samples collected from the Early Detection of Childhood Disabilities Center (E.D.C.D.C.)
Duhok. The population involved was the entire cases of both sexes that attended the centre during the period from
1
st.Jan, 1998 to 30th. Dec. 2008 with final diagnosis of hydrocephaly. Patients’ records from the centre were used to
collect data.
Results: Hydrocephaly has been recognized as a public health problem in Duhok province, Iraqi Kurdistan region,<

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Publication Date
Mon Jan 01 2018
Journal Name
Matec Web Of Conferences
Investigation of surface area of lakes and marshes from satellite images by using remote sensing and geographic information system integration in Iraq
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Water level and distribution is very essential in almost all life aspects. Natural and artificial lakes represent a large percentage of these water bodies in Iraq. In this research the changes in water levels are observed by calculating the areas of five different lakes in five different regions and two different marshes in two different regions of the country, in a period of 12 years (2001 - 2012), archived remotely sensed images were used to determine surface areas around lakes and marshes in Iraq for the chosen years . Level of the lakes corresponding to satellite determined surface areas were retrieved from remotely sensed data .These data were collected to give explanations on lake level and surface area fluctuations. It is imp

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Auditing the performance of the structural capital according to standards of e-learning and its reflection on the performance of universities: applied research
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The developments and transformations taking place in the era and the growth of knowledge economies and communication technology led this development to compel higher education institutions in Iraq to reconsider their objectives to keep pace with development. And one of the most important tools of development was the application of e-learning standards and its long-term impact on the performance of the educational institution. Performance auditing plays an important role in verifying the extent to which these institutions have implemented their activities and programs that auditing performance by adopting e-learning standards helps the institutions’ management by providing appropriate information on the extent to which they achieve thei

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Publication Date
Thu Jul 18 2024
Journal Name
Journal Of Economics And Administrative Sciences
The Role Of Cognitive Sharing In Enhancing The E-Learning Quality An Analytical Study Of A Sample Of Iraqi Universities
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The world faced many communication challenges in 2020 after the Covid-19 pandemic, the most important of which was the continuation of schooling. Therefore, the research aimed to analyze the current reality of the studied universities in terms of strengths and weaknesses and measure the implementing level of quality requirements of e-learning. This research studies the impact of knowledge sharing in its dimensions (behavior, organizational culture, work teams, and technology) on the e-learning quality and its dimensions (e-learning management, educational content, evaluation ,and evaluation). After conducting the survey, there was a difference in the universities’ application of the quality requirements of e-learning, as the study

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Publication Date
Tue Jan 27 2026
Journal Name
Al Ghary Journal Of Economic And Administrative Sciences
The impact of strategic knowledge on strategic improvisation: an exploratory study of some private hospitals in the city of Baghdad
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Publication Date
Fri Nov 09 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Assessment of Directly Observed Therapy Short Course (DOTs) Program Therapy in Treatment of Tuberculosis in Al-Sader City 2003-2005
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Objectives: Assessment outcome of DOTS (Directly observed therapy short course) program in Al-Sader City
Sector that was established by the WHO.
Methodology: Three cohorts groups of patients attending Baghdad TB institute and TB center in Al-Sader city
were followed retrospectively. The 1st cohort included (314) patients registered in year (2003), the 2nd cohort
included (327) patients registered in year (2004), the 3rd cohort included (321) patients registered in year
(2005). The collected data were analyzed for case detection, treatment outcomes, retreatment outcomes,
treatment success, and retreatment success in regard to time, age and sex.
Results: The following rates were extracted for the three cohort: Case det

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