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.
<p>In this paper, we prove there exists a coupled fixed point for a set- valued contraction mapping defined on X× X , where X is incomplete ordered G-metric. Also, we prove the existence of a unique fixed point for single valued mapping with respect to implicit condition defined on a complete G- metric.</p>
Abstract Since unmethylated CpG motifs are more common in DNA from bacteria than vertebrates, and the unmethylated CpG motif has recently been reported to have stimulatory effects on lymphocytes, we speculated that bacterial DNA may induce inflammation in the urinary tract. To determine the role of bacterial DNA in lower UTI, we intraurethrally injected prokaryotic DNA (extracted from E. coli) in white mice and performed histopathological study for the kidneys and urinary bladders, 24 h after the exposure. The results showed infiltration of inflammatory cells, shrinkage of glomerulus and increase the capsular space, as well as edema formation in kidney tissues. Moreover, urinary bladder sections showed infiltration of inflammatory cells.
... Show MoreBackground: Mental health of children has recently been
receiving increased attention in many parts of the world.
However, such attention has been lacking in developing
countries, particularly in the form of systematic research
Aim: The study aimed to find out the frequency of
behavior disorders in a sample of primary school children
and the different social and demographic factors that might
be related to this disorder.
Methods: The study is a cross-sectional one that included
918 primary school pupils in both urban and rural areas of
Baghdad. Rutter's questionnaire teacher's version was used
to assess the pupils, and the demographic data was obtained
by special questionnaire sent to the parents to be
Background: The influence of glucose metabolism is seen in many infectious diseases, making diabetic patients more vulnerable to sepsis and other serious sequelae of bacterial invasion such as UTI and vaginitis.Patients and method: sixty two patients (women) were suffering from GUTIs consulting Al-Elwya hospital from November- 2009 to March -2010. Two samples were taken from those patients (urine samples and vaginal swabs); these samples were cultured on Blood, Chocolate, and MacConkey's agar for isolation of bacteria.Results: The study group consists of sixty two women suffering from (GUTI), their ages range from 18-55 years. Thirty eight of them were diabetic women and twenty four of them were non- diabetic women. Twenty t
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Muslim scholars have established fundamental rules for deriving rulings to be a methodology for every mujtahid who wants to extract rulings from his reliable sources, and one of the most prominent fundamental rules on which many rulings are built is the permissible and the many rulings related to it.
Leaving what is permissible on its own terms sometimes causes embarrassment and distress in some cases, so we need something that restricts it. In our Islamic law, many legal rulings are embodied in which the restriction of what is permissible is in the public interest, or to relieve embarrassment in public.
Because of the importance of this fundamentalist rule, and the difference in some
... Show MoreStudies were conducted from 1980 to 1989 to determine the insect pests infested animal museum collections in Iraq. Twelve species of Coleoptera were recovered, eleven belonged to the Dermestidae, and one to the Tenebrionidae. Of these Anthrenus coloratus Reitt. and Phradonoma nobile (Reitt.) were the most commonest and widely distributed species. Trogoderma bactrianum Zhant. and Orphilus niger (Rossi) were recorded here for the first time in Iraq.
Constructal theory plays a major role in the conceptual design stage of the structural system in architecture. It provides a conceptual framework for predicting the form depending on natural systems to model those systems geometrically according to the constructal law that works in two directions: the first is towards predicting the general form of the structural system, and the second is the physical application of the law in the process of detailed design of the parts of the system. The aim of this paper is to determine the mechanism adopted in the structural design according to the constructal theory, assuming that the structural design according to the constructal theory achieves
The problem of the research lies in choosing agility tests suitable to the test taker to observe the relative changes in some players. In addition to that, there are a lot of agility tests that lack special test models that coordinate gender and age. This means the youth basketball player on one hand and time and distance in applying the tests on the other. The importance of the research lies in designing agility tests for youth basketball players to achieve variations in tests a matter that will benefit coaches in their training. The subjects of the research were (30) youth basketball players from the specialized school of the National Center that sponsor gifted basketball players in Baghdad for the season 2014 – 2015. The data was colle
... Show MoreGas Lasers are important tools that are used in variety purposes, for their low and (cw) output power. The aim of this study was to prepare a way to calculate an optimum stimulated emission cross-section in a gas laser containing a mixture of Xenon and Neon by (30%-70%). The process was a theoretical study of each gas in separate in terms of their physical properties as an active medium. The results of these calculations are logic and more convenient than other mixtures used before
The study includes the phytoplankton compositions in Alaaras Lake , in summer 2008 and winter , spring , summer 2009. Samples were collected from three selected sites at north , middle and south of lake. A total of 74 taxa of phytoplankton were identified . The diatoms were the dominated by 44 taxa represented 82.8% of the total indentified species, followed by green algae ( Chlorophyta ) of 20 taxa (8.5%), and blue green algae (Cyanophyta of 7 taxa (7.2%). Tow species were recorded of Pyrrophyta and one species of Euglenophyta .The seasonal variation for Diatoms density showed tow peaks during Autumn and summer. Few species were dominated during the most studied period such as Cocconeis placentula var. euglypta, Synedra fasciculata and
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