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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
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Budget Deficiency and Its Treatment Prospects and Policies with Reference to Iraq (2003-2012)
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Developed and underdevelopment countries, on equal terms, face the problem of budget deficiency. Budget deficiency means that the public expenditure surpasses the public revenues. This, on the international level, is one of the most serious economic problems with many direct effects on the national economy, and depends, basically, on its finance chosen method. Looking for a solution to this problem, for this reason and many other ones, has been highlighted in spite of the many attempts to reduce the role of the governmental expenditure. Budget deficiency can not be attributed to a single unique cause since it is complex phenomenons the causes of which are related to many factors contribute to its occurrence, some of which refer t

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Publication Date
Tue Jul 11 2023
Journal Name
Journal Of Educational And Psychological Researches
Psychological stability and its relationship to Integration University and spiritual intelligence among University students
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The current research aimed to identify psychological stability and its relationship to university integration and spiritual intelligence among university students. The research sample consisted of (158) students from the College of Education - Al-Mustansiriya University.

A scale was applied: psychological stability, university integration, and spiritual intelligence,   and by using the (Pearson) correlation coefficient, and the t-test, the results showed: the sample members enjoy psychological stability, university integration, and spiritual intelligence, and there is a positive, statistically significant correlation between the research variables, and the results resulted in some recommendations and proposals.

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Publication Date
Fri Aug 06 2021
Journal Name
Research Journal Of Pharmacy And Technology
Hepatitis B Surface Antigen level and its Correlation with Age, Gender, and Liver Biomarkers
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Background: Measuring the concentration of hepatitis B surface antigen (HbsAg) in HBV patients can be determined with immunoassay techniques. This study aimed to measure the HbsAg titers in chronic HBV patients and to assess its correlation with patients' ages, gender, and with the levels of liver enzymes and total serum bilirubin. Materials and Method: Fifty-eight chronic hepatitis B infected patients were enrolled in this study. Age and gender of the patients were recorded. HbsAg concentration was tested with automated Immunoanalyzer. The patients were also tested for ALT, AST, ALP, and TSB by automated chemistry analyzer. Results: All the chronic HBV patients have positive HBsAg titers above the negative cutoff (0.05U/L) with mea

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Publication Date
Thu Feb 12 2026
Journal Name
Journal Of Baghdad College Of Dentistry
An Evaluation of Ion Released from Two Brands of Brackets in Three Types of Mouthwashes
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Background: Mouthwashes used widely as ancillary to mechanical oral hygiene methods. Little information provided about the effect of mouthwashes on ions released from orthodontic brackets. Therefore, the present study has been established to evaluate the effect of different mouthwashes on the corrosion resistance and the biocompatibility of two brands of brackets. Materials and Methods: Eighty premolar stainless steel brackets were used (40 brackets from each brand). They were subdivided into four subgroups (n=10) according to immersion media (deionized distilled water, Corsodyl, Listerine and Silca herb mouthwashes). Each bracket was stored in a closely packed glass tube filled with 15ml of the immersion media and incubated for 45 days at

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Publication Date
Wed Jan 15 2003
Journal Name
كلية الترا ث الجامعة
Estimating an Exponentiated Expanded Power Function Distribution Using an Artificial Intelligence Algorithm
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The distribution of the expanded exponentiated power function EEPF with four parameters, was presented by the exponentiated expanded method using the expanded distribution of the power function, This method is characterized by obtaining a new distribution belonging to the exponential family, as we obtained the survival rate and failure rate function for this distribution, Some mathematical properties were found, then we used the developed least squares method to estimate the parameters using the genetic algorithm, and a Monte Carlo simulation study was conducted to evaluate the performance of estimations of possibility using the Genetic algorithm GA.

Publication Date
Mon Mar 13 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Comparative Study of The Amount of Apically Extrusion Of Debris During Root Canal Preparation Using Wave Oneâ„¢, Trushape 3Dâ„¢, Hyflexâ„¢ CM and One Shapeâ„¢ Instrumentation Systems (An In Vitro Study)
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Background: Many types of instruments and techniques are used in the instrumentation of the root canal system. These instruments and techniques may extrude debris beyond the apical foramen and may cause post-instrumentation complications. The aim of this study was to evaluate the amount of apically extruded debris resulted by using 4 types of nickel-titanium instruments (WaveOne, TRUShape 3D conforming files, Hyflex CM, and One Shape files) during endodontic instrumentation. Materials and methods: Forty freshly extracted human mandibular second premolar with straight canals and a single apex were collected for this study. All teeth were cut to similar lengths. Pre-weighted glass vials were used as collecting containers. Samples were randoml

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Publication Date
Tue May 22 2012
Journal Name
Thesis
Production and characterization of methionine γ- lyase from Pseudomonas putida and its effect on cancer cell lines
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Production and characterization of methionine γ- lyase from Pseudomonas putida and its effect on cancer cell lines

Publication Date
Sat Jul 01 2023
Journal Name
Chemical Methodologies
Acid Activation of Iraqi Bentonite Clay and Studying its Structural, Dielectric and Electrical Behavior at Various Temperatures
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Iraqi calcium bentonite was activated via acidification to study its structural and electrical properties. The elemental analysis of treated bentonite was determined by using X-ray fluorescence while the unit crystal structure was studied through X-ray diffraction showing disappearance of some fundamental reflections due to the treatment processes. The surface morphology, on the other hand, was studied thoroughly by Scanning Electron microscopy SEM and Atomic Force Microscope AFM showing some fragments of montmorillonite sheets. Furthermore, the electrical properties of bentonite were studied including: The dielectric permittivity, conductivity, tangent loss factor, and impedance with range of frequency (0.1-1000 KHz) at different temperatu

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Publication Date
Mon Jun 23 2025
Journal Name
Journal Of Biotechnology Research Center
Production of protein isolate and its enzymatic hydrolysates from local pumpkin seeds and studying their functional properties
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Background: Pumpkin seeds are a valuable source of high-quality protein and can be utilized as functional food ingredients due to their properties, such as solubility, foam formation, and stability. This study aims to produce protein isolate and its enzymatic hydrolysates from local pumpkin seeds to study their properties. Methodology: Preparing defatted pumpkin seeds for protein extraction, followed by the enzymes’ hydrolysis using Trypsin and Pepsin enzymes separately and together in two methods. The determination of amino acids and the degree of hydrolysis was conducted; moreover, protein properties were studied, including solubility, emulsifying activity, stability index, foaming capacity, and stability. Results: A protein sample was

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Publication Date
Wed Oct 10 2018
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
ISOLATION AND IDENTIFICATION OF FUNGI WHICH INFECT FENNEL Foeniculum vulgare Mill. AND ITS IMPACT AS ANTIFUNGAL AGENT
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    The study included isolation and diagnosis of fungi that infect Foeniculum vulgare Mill planted in the Department of Drugs and Medicinal Plants, Pharmacy College - University of Baghdad, different symptoms such as wilting and yellowing, stunting on the plants were observed fungi: Alternaria alternata, Rhizoctonia solani, Phoma herbarum and Fusarium oxysporum, The disease incidence ranging between 5-10%. Studied the effect of Foeniculum vulgare plant seeds extract against Alternaria alternata, Rhizoctonia solani, Phoma herbarum and Fusarium oxysporum,where tested  the concentrations  0,2.5 and 5%  of alcoholic extract of fennel seeds showed ef

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