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The Experimental Assessment of R134a and Its Lower GWP Alternative R1234yf in an Automobile Air Conditioning System
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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.

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Publication Date
Wed Jun 07 2023
Journal Name
Journal Of Educational And Psychological Researches
The Feeling of Job Alienation and Its Relationship to Organizational Commitment among Free Lecturers in Secondary Schools: Imam Al-Kadhum College (peace be upon him ( Kindergarten and Special Education Department
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The current study aims to identify the feeling of job alienation and organizational commitment among free lecturers in secondary schools, as well as to identify the significance of the differences in the feeling of job alienation according to the gender and the significance of the differences in organizational commitment according to the gender. It also aims to identify the correlation between the feeling of job alienation and organizational commitment. To achieve the objectives of the research, the researcher developed two scales: one consisted of (24) items to measure the vacancy in job alienation and the other consisted of (24) items to measure the organizational commitment. The two tools were applied to a sample of (200) male and fem

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Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Influence of Organizational Power on the Achievement of Entrepreneurship for Business Organizations An Analytical Study of the Views of a Sample of Managers in the Iraqi Ministry of Education
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This research aims to study the influence of organizational power on the achievement of entrepreneurship for business organizations. It is an analytical study of the views of a sample of managers in the Iraqi Ministry of Education. The research highlights the contribution that can be made from the knowledge of the theory of business organizations in achieving organizational success. The organizational power of the organization contributes to achieving entrepreneurship in the business environment and achieving a competitive position in the work environment. The research dealt with two variables: the first is the independent variable, the organizational power in its dimensions (Expend Power, Structural Power, Prestige Power). And t

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Publication Date
Wed May 01 2019
Journal Name
Desalination And Water Treatment
Synthesis and characterization of alumina-grafted acrylic acid monomer and polymer and its adsorption of phenol and p-chlorophenol
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Aluminum oxide (ALO) was grafted by acrylic acid monomer (AlO-AM) and then, it was polymerized to produce alumina grafted poly(acrylic acid) (AlO-AP). The prepared AlO-AM and AlO-AP were characterized by Fourier-transform infrared, differential scanning calorimetry , thermogravemetric analyzer and particle size distribution. Adsorption equilibrium isotherms, adsorption kinetics and thermodynamic studies of the batch adsorption process were used to examine the fundamental adsorption properties of phenol (P) and p-chlorophenol (PCP). The experimental equilibrium adsorption data were analyzed by three widely used two-parameters Langmuir, Freundlich and DubininRadushkevich isotherms. The maximum P and PCP adsorption capacities based on t

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Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
Synthesis of Six and Seven-membered Heterocyclic Molecules Containing an Adamantyl Fragment and an X-ray Crystal Structure of (E)-N-(adamantan-1-yl)-1-(3-nitrophenyl)methanimine
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       Our work included a synthesis of three new imine derivatives—1,3-thiazinan-4-one, 1,3-oxazinan-6-one and 1,3-oxazepin-4,7-dione—which contained an adamantyl fragment. These were produced via the condensation of the Schiff`s base (E)-N-(adamantan-1-yl)-1-(3-aryl)methanimine with 3-mercaptopropanoic acid; 3-chloropropanoic acid; and maleic, citraconic anhydride, respectively. These new imines were prepared via the condensation of adamantan-1-ylamine and 3-nitro-, 3-bromobenzaldehyde in n-BuOH. We obtained a good yield of products. FTIR, 1H NMR spectroscopy and C.H.N.S analysis were used to diagnostic the products. The molecular structure of (E)-N-(adamantan-1-yl

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Publication Date
Fri Apr 01 2022
Journal Name
Baghdad Science Journal
Interactive Effects of Major Insect Pest of Watermelon on its Yield in Wukari, Nigeria
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Watermelon is known to be infested by multiple insect pests both simultaneously and in sequence. Interactions by pests have been shown to have positive or negative, additive or non additive, compensatory or over compensatory effects on yields. Hardly has this sort of relationship been defined for watermelon vis-à-vis insect herbivores. A 2-year, 2-season (4 trials) field experiments were laid in the Research Farm of Federal University Wukari, to investigate the interactive effects of key insect pests of watermelon on fruit yield of Watermelon in 2016 and 2017 using natural infestations. The relationship between the dominant insect pests and fruit yield were determined by correlation (r) and linear regression (simple and multiple) analys

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Publication Date
Thu Nov 02 2023
Journal Name
Journal Of Engineering
Improving Voltage Stability in Kurdistan Power System in Areas with Deficit Power Production by Rescheduling the Active Power Based on PSS/E Simulation
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This paper aims to improve the voltage profile using the Static Synchronous Compensator (STATCOM) in the power system in the Kurdistan Region for all weak buses. Power System Simulation studied it for Engineers (PSS\E) software version 33.0 to apply the Newton-Raphson (NR) method. All bus voltages were recorded and compared with the Kurdistan region grid index (0.95≤V ≤1.05), simulating the power system and finding the optimal size and suitable location of Static Synchronous Compensator (STATCOM)for bus voltage improvement at the weakest buses. It shows that Soran and New Koya substations are the best placement for adding STATCOM with the sizes 20 MVAR and 40 MVAR. After adding STATCOM with the sizes [20MVAR and 40MV

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Publication Date
Thu Mar 31 2022
Journal Name
Psychological Science
The health and social repercussions of the epidemic crisis (Covid-19) on women (An exploratory study for some private universities - Baghdad / Karkh)
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The current research aims to first - reveal the social repercussions of COVID-19 on women A - The impact of the epidemiological crisis on the social structure of the family B - Psychological and social pressures that women are exposed to during the Covid pandemic C - Social isolation resulting from the injury of a member Second - Understanding the health consequences of COVID-19 on women A- Mechanisms of differentiation in the treatment of Covid-19 treatment, home or hospital As for the limits of the research, the current research is determined by some private universities of students, female employees and teaching staff in Karkh district, which number eight (Al-Hikma, Al-Farahidi, Al-Farabi, Tigris, AlTurath, Al-Rashid, Al-Mashreq, Al-Nuso

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Publication Date
Sun Jan 01 2017
Journal Name
Indian Journal Of Pathology And Microbiology
Assessment of topoisomerase II-alpha gene status by dual color chromogenic in situ hybridization in a set of Iraqi patients with invasive breast carcinoma
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Abstract Background: The human epidermal growth factor receptor 2(HER2) proto-oncogene is overexpressed or amplified in approximately 15%-25% of invasive breast cancers. Approximately 35% of HER2-amplified breast cancers have coamplification of the topoisomerase II-alpha (TOP2A) gene encoding an enzyme that is a major target of anthracyclines. Hence, the determination of genetic alteration (amplification or deletion) of both genes is considered as an important predictive factor that determines the response of breast cancer patients to treatment. The aims of this study are to determinate TOP2A status gene amplification in a set of Iraqi patients with breast cancer that have had an equivocal (2+) and positive HER2/neu by immunohistochemistry

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Engineering
Performance of Solar Adsorption Cooling System Using Methanol and Activated Carbon as a Working Pair
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The need for renewable energy sources is higher than ever due to rising global warming, climate change, and ozone depletion. For refrigeration and air conditioning applications, adsorption refrigeration systems are viable alternatives cooling techniques. This study is a topic and part of the M.Sc. thesis. A field solar-powered ice maker unit was created, studied, tested, and evaluated on the 13th and 30th of May, 2022. Activated carbon and methanol pair was used to set up a refrigeration system in Baghdad (Al Dora). Experimental tests were carried out outdoors to determine the coefficient of performance COP and specific cooling power SCP of the system. The results showed that the lowest temperature

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Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
Mesoporous Silica Nanoparticles as a System for Ciprofloxacin Drug Delivery; Kinetic of Adsorption and Releasing
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Mesoporous silica (MPS) nanoparticle was prepared as carriers for drug delivery systems by sol–gel method from sodium silicate as inexpensive precursor of silica and Cocamidopropyl betaine (CABP) as template. The silica particles were characterized by SEM, TEM, AFM, XRD, and N2adsorption–desorption isotherms. The results show that the MPS particle in the nanorange (40-80 nm ) with average diameter equal to 62.15 nm has  rods particle morphology, specific surface area is 1096.122 m2/g, pore volume 0.900 cm3/g, with average pore diameter 2.902 nm, which can serve as efficient carriers for drugs. The adsorption kinetic of Ciprofloxacin (CIP) drug was studied and the data were analyzed and found to match well with

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