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.
داء المشوكات الكيسي (CE) هو مرض وبائي يسبب مرضًا خطيرًا وخسائر اقتصادية في معظم بلدان العالم. MiRNAs هي عامل جيني ضروري لتنظيم الاستجابة المناعية من خلال قدرته على التدخل في التعبير الخلوي ؛ واحد هذه الحوامض النووية الدقيقة -146 أ. هدفت الدراسة الحالية تقييم إذا كان بإمكاننا استخدام microRNA 146a كمؤشر حيوي للكشف عن CEو تحديد العلاقة بين التعبير الجيني microRNA 146a و IL-17 في مرضى CE.حيث اشتملت الدراسة على 50 مريضًا من CE تم إد
... Show MoreIn recent decades, the identification of faces with and without masks from visual data, such as video and still images, has become a captivating research subject. This is primarily due to the global spread of the Corona pandemic, which has altered the appearance of the world and necessitated the use of masks as a vital measure for epidemic prevention. Intellectual development based on artificial intelligence and computers plays a decisive role in the issue of epidemic safety, as the topic of facial recognition and identifying individuals who wear masks or not was most prominent in the introduction and in-depth education. This research proposes the creation of an advanced system capable of accurately identifying faces, both with and
... Show MoreThe vision and philosophy of the economic system in Iraq after 2003 were not clear-cut because of overlapping internal factors was the novelty of the political system and the lack of political and economic decision makers to understanding and conviction full need shaping a new administration for the Iraqi economy is able to succeed economic development programs, and external factors was determinedly organizations international application of shock reforming style and contrary to the social reality and the security which reflected negatively on the work and consistency Lisseeash financial balance between stability and growth and raise the level of consumer spending and the importance of research lies in the ability of fiscal policy to achie
... Show MoreAs performers in a social world, we communicate with other people by sharing information on many different levels. Each utterance includes linguistic information and conveys much information about the speaker’s identity. Variation in voice quality indexes information about the speaker and marks the speaker’s identity as a unique individual. The present study aims to validate the belief that each individual has an inalienable voice print that can’t be imitated. The study verifies that, even the more similar personality between two individuals, or the close position in society the variance is voice quality. The acoustic analysis is performed via analysing the acoustic parameters namely: the fundamental frequency, amplitude, inten
... Show MoreMixing this strategy with a qualitative research design and an idea known as AI-supported journalism, the paper is going to approach the requirements of how AI technologies may transform journalism content and culture in a way beyond what one anticipates; therefore, enabling more of it to reach an audience. The current research used descriptive research design to investigate the potential applications of the AI tools that mediate civilizational conversation and a structured questionnaire to media professionals. AI-driven journalism can promote peaceful cohabitation and mutual respect and thus act as a bridge between cultures, the research said. The piece even goes on to mention the need for media establishments and civil soc
... Show MoreThe study of vegetative change of cities is one of the most important studies related to human life because of its direct correlation with the temporal conditions that occur. These include the economic problems that force people to move and look for job opportunities in the city, which leads to an increase in the population density of cities, especially for cities with an important economic and administrative location as in the capital city of Baghdad. In this study, the effect of the increasing in population density was analyzed on the urban planning of Baghdad city. The decreasing in vegetation was due to the increasing of urban areas on the outskirts of the city, which led to an increase in its area. Moreover, urban cities increased t
... Show MoreABSTRACT
Impkact of Knowledge sharing on organizational innovation Impriscal study in Arabic company .
of Knowledge Management is the main component Knowledge sharing system, it mean the exchange if Knowledge, ideas, and good practice with another individual . Knowledge sharing between persons, then its values can growth .
It is vry important because it can provide us with the contention between virus peoples . the interaction among the people can pass all kind of Knowledge among them. the connection and interaction and interaction enabl
... Show MoreThis study is concerned with the topic of the constant and the variable within the artistic theatrical phenomenon and specifically the accompanying music for the movements, scenes and dramatized idea, which translates the Iraqi environments (the serious ones). The researcher, here, tries to determine those variables and constants as a methodological scientific study to serve the scientific and cultural institutions and contribute in settling them intellectually, and entering them in the academic environments that depend on studying the artistic associations between the theatrical science and musical science. We find that this study which addresses the topic (the constant and the variable in the theatrical show music for the department of
... Show MoreThis research aims to study the contribution of social costs contribution to achieving social luxury in Al-Furat General Chemical Industries company that has considered second largest contamination in the area after the invasive power to deal with chemicals in manufacturing and very dangerous to individual society and environment ,this is first to play an effective role by the senior parties related to sense of social responsibility of the internal and external environment of the company to identify costs that are preventing ,reduced and treating damage caused and achieving sustainable development ,to achieve this goal and what they reached are the difficulty of accounting for the environment and social costs from final accou
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