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.
The creative arts in general and the theatre in specific represent man's rushing and carving for freedom, goodness and beauty, and the relation between creativity and freedom has always been fluctuating following the censorship pressures of all types and shapes the political, religious and social. Since the theatre is the closest and more touching creative art to the problems of the society of numerous types and levels and it was and has always been playing an enlightening role in shedding light on what the societies experiencing with crises and problems in all directions. The theatre, thus, derives the essence of existence from life, through topics concerned with what the human being is. It seeks to be the real witness and partne
... Show MoreAbstract A descriptive study was carried out on nurses who were working at burn. Units in Baghdad city hospitals, Al-Kindy , Al-Yarmook, Al-Qadisiya, Al-karkh, and Al-Karama hospital, in the period from 20th july 2003 to 20th November 2003. The study aimed to identify the nurses performance about pain management for burned patients at burn units and find out the relationship between the demographic characteristics and performance . A purposive (non-probability) sample of (40) nurses, (24) male nurses and (16) female. The data were collected through the use of observational checklist, which comprised (
Objectives: to assess Socio Demographic, Reproductive Characteristics, and healthy dietary behaviors. among women with osteoporosis . To determine the relationship between the socio demographic characteristics, reproductive data and dietary related behaviors. Methodology: A descriptive analytic design was conducted on Non- Probability ( purposive sample) of (90) women who have suffering from osteoporosis attend to (DEXADual-Energy X-ray Absorptiometry) unit in Merjan Teaching Hospital in Hilla City. A questionnaire has been used as a tool of data collection and consists of three part ;including : Soci
Abstract: E2F6 is a member of the E2F family of transcription factors involved in regulation of a wide variety of genes through both activation and repression. E2F6 has been reported as overexpressed in breast cancers but whether or not this is important for tumor development is unclear. We first checked E2F6 expression in tumor cDNAs and the protein level in a range of breast cancer cell lines. RNA interference-mediated depletion was then used to assess the importance of E2F6 expression in cell lines with regard to cell cycle profile using fluorescence-activated cell sorting and a cell survival assay using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The overexpression of E2F6 was confirmed in breast tumor cDNA samp
... Show MoreIn this paper, we propose a new and efficient ferroelectric nanostructure metal oxide lithium niobate [(Li1.075Nb0.625Ti0.45O3), (LNTO)] solid film as a saturable absorber (SA) for modulating passive Q-switched erbium-doped fiber laser (EDFL). The SA is fabricated as a nanocomposite solid film by the drop-casting process in which the LNTO is planted within polyvinylidene fluoride-trifluoroethylene [P(VDF-TrFE)] as host copolymer. The optical and physical characteristics of the solid film are experimentally established. The SA is incorporated within the cavity of EDFL to examine its capability for producing multi-wavelength laser. The experimental results proved that a multi-wavelength laser is produced, where stable four lines with central
... Show MoreElastic magnetic electron scattering form factors in Ca-41 have been investigated. 1f7/2 subshell has been adopted as a model space with one neutron, and Millinar, Baymann and Zamick 1f7/2 model space effective interaction (F7MBZ) has been used as a model space effective interaction to generate the model space vectors for the M1, M3, M5, M7, and total form factors. Discarded space (core and higher configuration orbits) have been included through the first order perturbation theory to couple the partice-hole pair of excitation with 2ћω excitation energy in the calculation of the form factors and regarding the realistic interaction density dependence M3Y as a core polarization interaction with five sets of modern fitting parameters. Fina
... Show MoreIn this work, substantial evidence was obtained for ligand reduction in cerium tetrakis acac complexes. Also, this ligand reduction of a negatively charged ligand proved to depend far less on the nature central metal than neutral ligands does. It is supposed that in Mz(acac)z complexes the charge is distributed evenly over the whole molecule. In this work these complexes were prepared and characterized by IR and CHN analysis to indicate the purities of these complexes. The electrochemistry techniques were shown as obtained for ligand reduction. This research was carried out at School of Chemistry and Molecular Science, Sussex University, U.K.
Background: laparoscopic cholecystectomy (LC) is getting popularity for the treating of symptomatic gall bladder disease; conversion from laparoscopic to open cholecystectomy (OC) is also common.
Objective : To find out the prevalence of causes, risk factors of conversion from LC to OC among patient suffering from gall bladder disease, and to explore the most common causes of conversion from laparoscopic to open cholecystectomy.
Methods: This prospective study was conducted in the department of general surgery at Alkindy teaching hospital from first of January 2016 to the end of December 2017 .Nine hundred twenty patient were included. Patient age, gender, his
... Show MoreThe research covered Creeds in Assyrian Sculpture
(Assyrian Sculptures) The ability of the Assyrian sculptor to
contrast these creeds and tendon in Assyrian sculpture, in various variations, including prominent and stereotypical plaques and winged bulls, in addition to the obelisks and hunting scenes of the Lionسion hunting scenes of the black
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