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.
Objective(s): To assess nurses' practices for neurological unconscious patients in intensive care units.
Methodology: A descriptive study was conducted that included (50) nurse who are working in intensive care
units in hospitals and departments of the nervous system in (4) hospitals (neuroscience hospital, teaching
neurosurgical hospital, surgical specialist hospital, and sheck zaied hospital) in Baghdad city from March, 30th
,
2009 to July, 30th 2009 for the purpose of assessing their skills towards unconscious patients. A purposive "nonprobability
sample" was selected that consisted of (50) nurse who are working in intensive care units. A
questionnaire format and observational checklist were used which consist of
The research problem stems from a chief question: “What is the nature of the responsibility that «Al-Sabah Al-Jadeed» and «Al-Mada» Newspapers have undertaken in promoting the values of citizenship and national belonging in the society? The research aims to achieve a number of goals, including: Determining the most prominent themes that were emphasized in the opinion articles in these two newspapers within the framework of the responsibility of promoting the values of citizenship and national belonging in society, and revealing the most prominent topics that were discussed in opinion articles in the two sample newspapers regarding the promotion of the mentioned values. This research is a desc
... Show MoreThe Recent days witness an in creasing importanc of Islamic Banks which stems from the wide spread in Islamic and non-Islamic countries,Especially in USA and European countries.the consideration in Islamic Banks came after the financial crisis in 2008.Islamic Banks work with conventional banks in most countries,that is,the formers may face the same risks which face the latters,that represent the larger percent of the International Banking system.the problms that may affect Islamic Banks related to many causes,some related to the working in common economic environment.others related to the possibility of simulation to the method of investment and financing in conventional Banks,this mean,the work with principles not compling with
... Show MoreJumping ability is a fundamental variable in many sports, as its execution requires an integration of muscular strength Q1 and certain biomechanical variables. This is particularly evident in gymnastics jumping events and jump shots in ball games, both of which rely on a high level of vertical resistance. Vertical resistance serves as an indicator of an athlete’s ability to overcome their body weight while counteracting gravitational force to achieve optimal performance. As such, it is considered one of the key factors in movements that demand explosive power and speed. The researchers believe that despite the significant relationship between vertical resistance, speed-strength of the arms and legs, and certain biomechanical varia
... Show MoreThe current research sheds light on an important aspect of the great and rapid development in the field of science and technology and modern manufacturing methods as a result of the scientific revolution resulting from the accelerated cognitive development, which prompted designers in general and interior design in particular to exploit and invest in digital technology and the development of digital control in the process of designing the industrial product for the purpose of creativity and innovation through these digital programs Digital models achieve the requirements and desires of the interior designer according to the creative skill using modern software with high efficiency And extreme accuracy that is consistent with the requirem
... Show MoreTourism is a human phenomenon and economic and social activity. It represents an effective forces in the life of the individuals and state alike. As any other economic and human activity has appositive and negative results.
So there is a necessary to planning and activate this sector to get the most possible advantage.
Tourism has special importance out of its effect on the structure and performance of national economy. It can be regarded a dynamic activity with mutual effect include all the economic activities within and out the state. Tourism is affected and affect the production con summing , joineries , communication , ports ,hotel , restaurants ,internal and
... Show MoreThe current research aims through its chapters to verify the relationship and impact of strategic leadership as an independent variable in the marketing performance as a respondent variable, in a leap cement plant, and try to come up with a set of recommendations that contribute to enhancing the practice and adoption of the two variables in the organization under discussion. And based on the importance of the research topic to the community, and to the researched organization and its members, the analytical and analytical approach was adopted in the completion of this research, and the research community included a leap cement plant in Anbar Governorate, while the research sample was represented by (department heads, and people o
... Show MoreRefuse derived fuel (RDF) is considered one of the most important types of low cost thermal energy which can be tapped in the industry, especially the cement industry in particular being the need of high thermal energy during the production processes, and in this paper we have implemented the use of a derivative of the fuel RDF as a substitute for gasoline , to reduce production costs and thereby achieve production efficiency, and the methodology used in this research statistical analysis as well as the use of the cost of kaizen target for the purpose of reducing costs and achieve production efficiency, and this has reduced the cost total cement production by which led to reduce total costs of cement production by 8.4% and an incre
... Show Moreتتبلور فكرة البحث حول التوصل لنوع العلاقة التي تربط التعليم الالكتروني خلال جائحة كورونا برفع المهارات التكنولوجية للأساتذة والطلاب، وتبرز أهمية البحث في ان نجاح الوصول لهذه العلاقة يمكن الإفادة منها في تغيير منهجية تطوير المهارات التكنولوجية مستقبلا وذلك باعتماد الجوانب التطبيقية الفعلية بدلا من الدورات وورش العمل والتي قد لا تضاهي الطريقة العملية في رفع مستوى المهارات المختلفة سواء التدريسية او التكنو
... Show MoreThe musical templates are the fundamental reason for admiration and interest among a lot of cultural and societal medias because of the beauty of it's melodic value, where a lot of Iraqi singing and music specialists and composers try to consolidate daily life idea and translate it into music in a manner that preserve the template and rhythm horizontally and vertically, through the involvement of the scientific and philosophical concepts and theories of modern thought to reach the recipient,, as is the theory of form (Gestalt), one of the most important theories that stretched to their interpretations to the field in general art and in music science, especially, as an area that can be manifested as partial components template music, conn
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