The performance of a vapor compression refrigeration system (VCRS)-based residential air conditioner operating in a high-ambient temperature (HAT) country was investigated using six zero-ODP (ozone depletion potential) refrigerants as replacements to R22. The non-flammable alternative refrigerants considered in the present research were R134a, R404A, R407C, R410A, R448A, and R507A. Using the basic conservation laws, the VCRS was modeled during steady-state operation and solved using engineering equation solver (EES) software. Coefficient of performance (COP), pressures and temperatures at compressor suction and discharge, Global Warming Potential (GWP), critical pressure and temperature, compressor pressure ratio, volumetric cooling capacity (VCC) specific cooling capacity (SCC), and refrigeration effect were utilized as assessment criteria for the alternative refrigerants considered. From these refrigerants, the highest values of suction pressure, discharge temperature, and condenser pressure were attained by R410A. In addition, the discharge temperatures for all refrigerants, except R134a, were all higher than their corresponding critical values, causing a quicker drop in the VCRS’s performance. As an alternative refrigerant, R407C showed the highest SCC of 141.0 kJ/kg followed directly by 139.2 and 138.0 kJ/kg for R410A and R448A, respectively. A reverse trend was found for VCC with respective values of 4722 and 3775 kJ/m3 for R410A and R448A. Lower volume flow rates and smaller-sized compressors are expected for higher VCC refrigerants. The same trend was found for the compressor’s specific work input and condenser’s specific heat transfer with values of (51.14, 46.82, and 45.38 kJ/kg) and (190.3, 187.8, and 183.4 kJ/kg) for R410A, R407C, and R448A, respectively. For applications in HAT countries, larger condenser’s specific heat transfer makes the refrigerant more applicable. Conversely, with respect to COP, refrigerant R134a with a value of 3.075 was the superior alternative followed by R448A and R407C with respective COPs of 3.042 and 3.011. Based on the overall assessment in terms of environmental obligation, COP, compressor input power, refrigerant flow rate required, and all the evaluations made in this research, refrigerant R448A was recommended as the most appropriate substitute to R22 which can effectively be used in residential air conditioners in a HAT country.
Neurolinguistics is a new science, which studies the close relationship between language and neuroscience, and this new interdisciplinary field confirms the functional integration between language and the nervous system, that is, the movement of linguistic information in the brain in receiving, acquiring and producing to achieve linguistic communication; Because language is in fact a mental process that takes place only through the nervous system, and this research shows the benefit of each of these two fields to the other, and this science includes important topics, including: language acquisition, the linguistic abilities of the two hemispheres of the brain, the linguistic responsibility of the brain centers, and the time limit for langua
... Show MoreThe developments in forensic DNA technology have led us to perform this study in Iraqi population as reference database of autosomal Short Tandem Repeat (aSTR) DNA markers . A total of 120 unrelated individuals from Wasit province were analyzed at 15 STR DNA markers. Allele frequencies of DNA typing loci included in the AmpFlSTR1 IdentifilerTM PCR Amplification Kit panel from Applied Biosystems (D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, TH01, TPOX, CSF1PO, D19S433, D2S1338, D16S539) and several forensic efficiency statistical parameters were estimated from all the sample. the combined Matching Probability (CMP) using the 15 STR genetic loci in Iraqi population was estimated at 1 in 2.08286E-18 and the Combined
... Show MoreIn this paper, there are two main objectives. The first objective is to study the relationship between the density property and some modules in detail, for instance; semisimple and divisible modules. The Addition complement has a good relationship with the density property of the modules as this importance is highlighted by any submodule N of M has an addition complement with Rad(M)=0. The second objective is to clarify the relationship between the density property and the essential submodules with some examples. As an example of this relationship, we studied the torsion-free module and its relationship with the essential submodules in module M.
The purpose of this paper is to statistically classify and categorize Building Information Modelling (BIM)-Facility Management (FM) publications in order to extract useful information related to the adoption and use of BIM in FM.
This study employs a quantitative approach using science mapping techniques to examine BIM-FM publications using Web of Science (WOS) database for the period between 2000 and April 2018.
The findi
This study aims to study argumentation in political debates by figuring out the logical fallacies employed in the debates of Clinton and Trump, the presidential nominees of the 2016 elections, and Biden and Trump, the leading contenders in the 2020 United States presidential election. The study attempts to answer the questions: (1) What relevance fallacies are adopted in the debate between Trump and Clinton? (2) What rhetorical devices are used to influence the audience and gain voters besides fallacies in the debates selected? The study analyses two texts from two arguments using Damer's (2009) taxonomy of relevance fallacy and rhetorical devices based on Perrine’s (1969) model of communication and interpersonal rhetoric to answe
... Show MoreOne of the artificial lightweight aggregates with a wide range of applications is Lightweight Expanded Clay Aggregate. Clay is utilized in the production of light aggregates. Using leftover clay from significant infrastructure development projects to manufacture lightweight aggregates has a favorable environmental impact. This research examines the expanded clay aggregate production process and the impact of processing parameters on its physical and mechanical qualities. It also looks at secondary components that can be used to improve the qualities of concrete with expanded clay aggregates. The effect of the quantity of expanded clay aggregate on the fresh, hardened, and durability qualities of concrete is also studied.
... Show MoreLead-free 0.88(Na0.5Bi0.5)TiO3–0.084(K0.5Bi0.5)TiO3–0.036BaTiO3 (BNT–BKT–BT) piezoelectric ceramics were prepared using the conventional mixed-oxide method with a sintering temperature range of 1120–1200 °C. The effect of the sintering temperature on the crystal structure, microstructure, and densification, as well as the dielectrics, piezoelectrics, and the pyroelectric properties of BNT–BKT–BT ceramics were investigated. Scanning electron microscopy and X-ray diffraction were used to study the microstructures of the sintered samples. The results showed that the increase in sintering temperature was very effective in improving both the density and electrical properties. However, the samples deteriorated when the sintering te
... Show MoreThis study conduct in Al-Muthanna governorate to assess five concentrations of
This study aims at describing the identity crisis of Diaspora people (Arab -American) in "Laila Halaby's" novel "Once in A promise Land". Halaby tackles the issues of racism, exclusion, and instability of identity that affect the Arab American community after the terrorist event of eleventh of September. She sheds light on the experiences of her significant characters Salwa and Jassim in America, clarifying how this event weakened their social position and turns their presence in America questionable. "Halaby" describes the bitterness of her characters who are induced into a dream of belonging to a land that transcends their original culture and religious values as well as their language. "Halaby" explains the subsistence in America involvi
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