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.
The research aims to study the reliability of government institutions, including the audit directors, which are one of the most important oversight formations in the Ministry of Construction, Housing and Public Municipalities, on which the responsibility for comprehensive auditing of all the Ministry's (municipalities) formations falls on the Managing the Audit Program according to the specification (ISO 19011: 2018) to improve the audit performance which requires compliance with the application of the audit management system in accordance with the standard Specification (ISO 19011: 2018), depending on the methodology of the case study, and using of checklists, which were chosen ac
... Show MoreThe purpose of this paper is to identifying the results of the clubs participating in the men's Volleyball Premier League for the period from (1991) to (2022), archive the results of the Iraqi clubs participating in the Iraqi Premier League for men for the period from (1991) to (2022), and diagnosing and analyzing the causes of fluctuation in the participation of some Iraqi clubs in the Premier League for men for the period from (1991) to (2022). The nature of the research necessitated that the researcher use the historical approach or the so-called documentary approach, taking advantage of the historical development that took place for the participation of Iraqi clubs for men in the Premier League from (1991) until 2022), the last league h
... Show MoreThe subject of the strategic vision is of great importance to all companies because they live in an environment of rapid change in various areas of life. Supports the performance of its operations in a better way, towards appropriate strategic growth and achieving success. The research aims to determine the level of interest of the researched company in the research variables (strategic vision and growth strategy), and the importance of the research came in being an attempt to provide the theoretical and scientific foundations for the research variables (strategic vision and growth strategy). As for the research method, it was relied on the descriptive analytical method, relying on the questionnaire as a means of obtaining data from the
... Show MoreAutorías: Omar Saeed Sabbar, Ali Mousa Jawad, Maher Amer Jabbar. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 3, 2023. Artículo de Revista en Dialnet.
The research aims to study the basic concepts of the underwriting policy with its various indicators. The researcher studies the underwriting policy with its various indicators (sex, health status, age of the insured, insurance amount, The method of acceptance, payment method, and duration of insurance) where each of these indicators constitute an important factor in the productivity of life insurance policies, where the productivity of life insurance policies face many difficulties because insurance is a service and not a tangible material commodity and its benefits and not current. Therefore, the life insurance company needs to use a prudent underwriting policy so as not to endanger its financial position due to the expansion of the un
... Show MoreSewage water is a mixture of water and solids added to water for various uses, so it needs to be treated to meet local or global standards for environmentally friendly waste production. The present study aimed to analyze the new Maaymyrh sewage treatment plant's quality parameters statistically at Hilla city. The plant is designed to serve 500,000 populations, and it is operating on a biological treatment method (Activated Sludge Process) with an average wastewater inflow of 107,000m3/day. Wastewater data were collected daily by the Mayoralty of Hilla from November 2019 to June 2020 from the influent and effluent in the (STP) new in Maaymyrh for five water quality standards, such as (BOD5), (COD), (TSS), (TP)
... Show MoreAbstract:
The distribution or retention of profits is the third decision among financial management decisions in terms of priority, whether at the level of theory or practice, as the issue of distribution or retention is multi-party in terms of influence and impact, as determining the optimal percentage for each component is still the subject of intellectual debate because these decisions are linked to the future of the organization and several considerations, The research focus on the nature of the policies followed by the Iraqi banking sector As the sample chosen by the intentional sampling method was represented by the Commercial Bank of
... Show MoreMy research deals with the positions that the Prophet (PBUH) distressed. And condolences to those who lost her father and other problems and calamities that impede the life of women, has been given to the Lord of men, and good qualities, to strike the nation's finest proverbs in ensuring lost and lost of women and children, to be shown to us humanity in its finest form, and the best analyzed, and I hope God help And guidance and Rashad
The problem of the tagged research (experimentation in the works of the artist Muhammad al-Kinani is an analytical study) dealt with the nature of the concept of experimentation and its work in the works of Muhammad al-Kinani. Which adopts the removal of the concept of style and artistic style and takes the experience away from the pattern of repetition The importance of the research comes through the identification of the materials founding the artistic work. The current research benefits the specialists in the field of arts from the students of studies with a new and renewed formulation of creativity. The research objectives shed light on the contemporary experiences of the artist Muhammad Al-Kinani and its importance in benefiting res
... Show MoreThe current research included (the evaluation of Information Security Management System on according to international standard (ISO / IEC 27001: 2013) in Iraqi Commission for Computers and Informatics), for the development of an administrative system for information security is considered a priority in the present day, and in the light of the organizations dependence on computers and information technology in work and communication with others. The international legitimacy (represented by the International Organization for standardization (ISO)) remains the basis for matching and commitment and the importance of the application of information Security Management System accordi
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