Refrigerant R134a has been widely utilized in automotive air conditioning systems (AACSs); R134a has a high global warming potential (GWP) of 1430 despite having zero ozone depletion potential (ODP). Coming refrigeration systems must include refrigerants with low GWP and zero ODP. The aim of this experimental study is to evaluate the thermal performance of an (AAC) with different values of compressor speeds, i.e., (1000, 1700, and 2400 rpm) and two thermal loads, i.e., (500 and 1000 Watt) with the absence and presence of liquid suction heat exchanger (LSHX) using R134a. The results showed that adding LSHX enhanced the COP cycle by 7.18%, 10.7%, and 3.09% for the first, second, and third speed, respectively, at 500 Watt, while the enhancements were 10.27 %, 23.3 %, and 11.5 % for the first, second, and third speed, respectively, at 1000 Watt. Increasing the compressor speed decreased COP due to a reduction in RE and increased the compression effect, increasing the work done by the motor on the compressor that caused a reduction in COP. The compressor exergy destruction (X des. Comp.) decreased when LSHX was added by 6.13%, 2.22%, and 18.8% for the first, second, and third speed, respectively. However, X des. comp. increased with compressor speed due to the system’s pressure difference rise because of decreasing evaporation and increasing condensation pressures. As a result, the entropy generation increased. The increase in discharge temperature and pressure of the compressor led to a high friction force between the moving part of the compressor and the refrigerant, so the energy losses increased. Increasing the compressor speed decreased the total exergy performance of the cycle by 5.8 %, 7.5 %, and 16.7 % for the first, second, and third speed, respectively, due to increasing the compressor discharge temperature, increasing the X des. comp. and thermostatic expansion device and decreasing condenser and evaporator. Increasing X des. comp was higher than the destruction in the condenser and evaporator, which canceled the effect of others, so the total exergy performance of the cycle decreased.
This research aims to determine the importance of the role that agile leadership plays in supporting programs and areas of investment in human capital, as it is the most important type of capital that the organization possesses and achieves returns that are many times the cost it bears, due to its rare and valuable characteristics. Through six behaviours: (humility behaviour, calm behaviour, wisdom behaviour, patience behaviour, objectivity behaviour, trust behaviour). As for investment in human capital, it was measured through its four elements (skills, knowledge, capabilities, experiences). Despite this, the researched organizations suffer from a decrease in awareness of the importance of this type of investment and the role of
... Show MoreThe excellence and uniqueness is what makes the artwork creative or not, and the School of Op. Art in Iraq came to reveal new phenomena distinct style, unique in units built, although a few worked in this aspect of the art, but they left their mark distinct, in the research, construction and installation of what binds them in heritage and civilization, it is a new vision of linking the past with the present, they adopt and engineering units may be architectural sometimes in composition, concluded a researcher at the end of the research to the main findings and conclusions, which is that more business was a square-shaped or semi-square, which is commensurate painting with visual, which is a set of vocabulary or repeat units, we do not fin
... Show MoreDue to the increase in the number of the satellite channels which resulted from the satellite broadcasting, the demand for the television drama production has increased dramatically, and there has been a significant competitive market, which encouraged the producers to adopt many carrots among them the inclusion of TV series large scenes whose main purpose is to show the volume of the production in the series, let alone achieving the dramatic function. The researcher called this type of scenes (the productive scenes), a name which has not been used before. The researcher studied these scenes and determined his research subject under the title (the production scenes in the TV series) where the research problem has been determined through
... Show MoreInternet paths sharing the same congested link can be identified using several shared congestion detection techniques. The new detection technique which is proposed in this paper depends on the previous novel technique (delay correlation with wavelet denoising (DCW) with new denoising method called Discrete Multiwavelet Transform (DMWT) as signal denoising to separate between queuing delay caused by network congestion and delay caused by various other delay variations. The new detection technique provides faster convergence (3 to 5 seconds less than previous novel technique) while using fewer probe packets approximately half numbers than the previous novel technique, so it will reduce the overload on the network caused by probe packets.
... Show MoreDuring recent decades, hundreds of thousands of Iraqis lost their lives as a result of wars, economic blockade, or acts of violence and terrorism. The loss of a family member, especially husband makes women suddenly bears full responsibility for the family. Lost could impose new changes in psychological, social, and economical roles. These changes usually combine with the negative effects aftermath the lost trauma. Some of the reports in Iraq showed there were increased and huge numbers of widows and orphans. This study aimed to identify the aspects of Posttraumatic Growth (PTG) in Iraq women who lost their close relatives (especially husbands). 52 of Iraqi women who lost their husband and 49 women who experienced other traumatic events
... Show MoreThe roots of international relations: peace or war: A critical review A great debate has taken place about international relations between scholars concerning peace and War .The concept of root is matched with that of exception. And the importance of the research lies in the ensuing results in the report about the legitimacy of war and the space it holds, so if the origin of international relation is war .the obstacles against it are going to decrease .and if the origin lies in peace then the dimension of its legitimacy will narrow. key words: international relation –peace-war. Résumé : L’Origine des relations internationales : guerre ou paix : révisions critiques L’origine des relations internationales entre guerre et paix, a s
... Show MoreVirtual platforms are online classes used in teaching and learning EFL that let both teachers and students connect, communicate and cooperate online in real time. Learners get access to educational possibilities at home easily. Virtual classes can be conducted using a variety of techniques, including video conferencing, Google Meet, Zoom, conversations, reactions, and screen sharing. Users can access these programs on a range of gadgets, including laptops, tablets, and smartphones. The COVID-19 coronavirus pandemic affected all educational institutions, including schools, colleges, and universities. Our Iraqi educational institutions have been switched to use virtual platforms in this pandemic, much as all other foreign institutions
... Show MoreIntelligent or smart completion wells vary from conventional wells. They have downhole flow control devices like Inflow Control Devices (ICD) and Interval Control Valves (ICV) to enhance reservoir management and control, optimizing hydrocarbon output and recovery. However, to explain their adoption and increase their economic return, a high level of justification is necessary. Smart horizontal wells also necessitate optimizing the number of valves, nozzles, and compartment length. A three-dimensional geological model of the As reservoir in AG oil field was used to see the influence of these factors on cumulative oil production and NPV. After creating the dynamic model for the As reservoir using the program Petrel (2017.4), we
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