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Exergy Analysis of a Domestic Refrigerator
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An energy and exergy thermodynamic analysis using EES program was done for a domestic refrigerator working with R-134a using vapor compression refrigeration cycle. The analysis deals with the system component, i.e. compressor, condenser, evaporator and the expansion device. The analysis depends on the entropy generation minimization approach to improve the refrigerator performance by exploring the optimum design points. These design points were derived from three different theories governing the entropy generation minimization using exergy analyzing method. These theories were first applied to find the optimum balance between the hot inner condenser area and the cold inner evaporator area of the refrigerator and between its hot and cold thermal conductances. Nine types of condensers were used according to its internal surface area and thermal conductance, in order to reach the minimum entropy generation in the refrigerator. The results showed that the compressor has the lowest exergy efficiency of 25%. The expansion device was the second component after the compressor with exergy efficiency of 92%, followed by the condenser with an efficiency of 93%. The evaporator was found to have an exergy efficiency of 98 %. The experimental tests were repeated for the nine condensers sizes with three different ambient temperatures 25℃, 30℃ and 35℃.  The exergy analysis showed that the design of the refrigerator mainly depends on thermal conductance calculations rather than the surface inner area estimation.

 

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Publication Date
Mon Jan 26 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of the Efficiency of Three Different Obturation Techniques to Obturate the Isthmus Area of Roots Canals Prepared by Two Different Instrumentation Techniques (An In Vitro Study)
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Background: The isthmus is a difficult area in the root canal complex to manage. The research aimed to evaluate the efficiency of three different obturation techniques (lateral condensation, EandQ (thermoplasticized gutta percha system) and Soft Core (thermoplasticized core carrier gutta percha system)) to obturate the isthmus area of roots prepared by two different instrumentation techniques (rotary ProTaper universal and ProTaper Next systems). Material and method: Sixty freshly extracted teeth were randomly divided into two main groups (A and B) of 30 teeth each. Group A was prepared by rotary ProTaper Universal whereas group B was prepared by ProTaper Next system. Each main group was then randomly subdivided into three subgroups of 10 t

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Selection of the initial value of the time series generating the first-order self-regression model in simulation modeAnd their impact on the accuracy of the model
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In this paper, compared eight methods for generating the initial value and the impact of these methods to estimate the parameter of a autoregressive model, as was the use of three of the most popular methods to estimate the model and the most commonly used by researchers MLL method, Barg method  and the least squares method and that using the method of simulation model  first order autoregressive through the design of a number of simulation experiments and the different sizes of the samples.

                  

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Global Pharma Technology
Calculation of Stabilization Energy of Tetrahedrane with its Nitrogen Substituted Derivatives by DFT Method and Driving an Empirical Relation Connect it with Charge Functions of the Molecule
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In this work the strain energy of tetrahedrane and its nitrogen substituted molecules were calculated by isodesmic reaction method according to DFT quantum chemical fashion, the used basis set was 6-31G/B3-LYP, in addition all structures were optimized by RM1 semi-empirical method. From the obtained data we estimate an empirical equation connect between strain energy of the molecule with charge functions represented by dipole moment of the molecule plus accumulated charge density involved within the tetrahedron frame plus the number of nitrogen atoms. The results indicate the charge spreading factors by polarization and processes are the most important factors in decreasing the strain energy.

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Publication Date
Sat Nov 11 2023
Journal Name
Journal Of Dental Research, Dental Clinics, Dental Prospects
Investigating the effect of Er,Cr:YSGG laser agitation of sodium hypochlorite on the removal of mature biofilm in the complex root canal systems using atomic force microscopy
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Background. Endodontic infections caused by remaining biofilm following disinfection with chemical fluids encourage secondary bacterial infection; hence, employing laser pulses to activate the fluids is advised to improve microbial biofilm clearance. This study investigated the performance of Er,Cr:YSGG laser in photon-induced photoacoustic streaming (PIPS) agitation of 5.25% sodium hypochlorite (NaOCl) to enhance the removal of mature Enterococcus faecalis (E. faecalis) biofilms in complex root canal systems. Methods. The mesial roots of the lower first and second molars were separated and inoculated with E. faecalis bacteria for 30 days. The roots were irrigated with 5.25% NaOCl, some of them were agitated with passive ultrasonic

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Publication Date
Thu Jun 27 2019
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
FIRST RECORD OF SOLOSTAMENIDES PAUCITESTICULATUS KRITSKY & ÖKTENER, 2015 (MONOGENOIDEA, MICROCOTYLIDAE) FROM GILLS OF ABU MULLET PLANILIZA ABU (HECKEL, 1843) FROM EUPHRATES RIVER OF SAMAWA CITY, SOUTHERN IRAQ
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    A total of 54 abu mullet Planiliza abu (Heckel, 1843) were collected from two stations (north and south stations) along the Euphrates River near Samawa City, Al-Muthanna province and were examined during the period from October 2016 till September 2017 for parasites. Six out of 35 examined fishes from the north station (17.1%) and one out of 19 examined fishes (5.3%) from south station were infected with the microcotylid Solostamenides paucitesticulatus Kritsky & Öktener, 2015. The parasite was illustrated and described, and it is considered as a new record for the parasitic fauna of fishes of Iraq.

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Publication Date
Mon Aug 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Business Process Reengineering in the institutional performance : Research in the office of the General Inspector in the Ministry of Higher Education and Scientific Research
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Abstract

       This research is aimed at indicating the impact of business process reengineering on corporate performance in the Office of the Inspector General of the Ministry of Higher Education and Scientific Research of the Iraqi study has identified a problem in a number of the most important questions - what the impact of the Business Process Reengineering at the corporate office performance indicators respondent? What are the actual results of the analysis of paths Administrative Process Engineering and Corporate Performance respondent in the office? In order to achieve the goal of the research and answer the questions of the problem, the study applied to a sample of

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Publication Date
Mon Jan 09 2023
Journal Name
College Of Islamic Sciences
The door of speaking souls From the book explaining the features of the origins of religion For Sheikh Abdul Rahman bin Abdullah Al-Khonji study and investigation
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Praise be to God who created the soul, perfected it, and inspired it with its immorality and piety. He says in His Noble Book: ﭤ Fajr: 27-30 Glory be to You, O God! O Lord, on whom I have chosen for You as a beloved from myself and the soul of the two worlds, may our master Muhammad be sacrificed for him, who enlightened the horizons with his introduction to enlightenment. It soon ends with the end of pleasure, which is the opposite of the pleasure of thought and meaning, as it is permanent and continuous, and from here we see that the Messenger of God, may God’s prayers and peace be upon him, urges us in various places to seek knowledge and fortify the soul and thought in a way that raises one’s status and protects him from the st

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
The application of quality requirements in the Ministry of Labour and Social Affairs using the international standard (ISO 9001: 2015) Korean case study of the Iraqi Center
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This research aims to study the mechanism of application of international specification requirements (ISO 9001: 2015) at the Iraqi Center- Korean Vocational Training return to vocational training department at the Ministry of Labour and Social Affairs for the purpose of preparing and creating the center to get a certificate of conformity with the requirements of the standard (ISO 9001: 2015) that would elevate the level of performance and services provided in the respondent Center after it is identified and the study of the reality of the quality management system by identifying strengths and weaknesses in the system to diagnose the gap and find ways to address that gap, and adopted the researchers the case study method to conduc

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Publication Date
Fri Oct 01 2021
Journal Name
Journal Of Al-rafidain University College For Sciences ( Print Issn: 1681-6870 ,online Issn: 2790-2293 )
The Use of Logistic Regression Model in Estimating the Probability of Being Affected By Breast Cancer Based On the Levels of Interleukins and Cancer Marker CA15-3
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Breast cancer has got much attention in the recent years as it is a one of the complex diseases that can threaten people lives. It can be determined from the levels of secreted proteins in the blood. In this project, we developed a method of finding a threshold to classify the probability of being affected by it in a population based on the levels of the related proteins in relatively small case-control samples. We applied our method to simulated and real data. The results showed that the method we used was accurate in estimating the probability of being diseased in both simulation and real data. Moreover, we were able to calculate the sensitivity and specificity under the null hypothesis of our research question of being diseased o

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Publication Date
Sat Feb 09 2019
Journal Name
Journal Of The College Of Education For Women
The biography of King Faisal I from the early period of his life to his building to the first step of the modern Iraqi state (1883-1924)
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The environment and the placesthat prince Faisal Bin AL-Husein influenced his childhood ,
behaviourand future . his expereence in his early life in leading the battles and
arabRevoluionenriched him . inspite of his short periedand harsh experience of leadersmp.
he gained an experienencein ruling iraqadter 1921 . The Syrian experiencetaught him how to
deal with the strong and establish the government as he beliered in the slogan: independence
is taken not given. He established the consititution and the election . he made a solid
basefeconomy of in his time, Iraq , Iraq be came the country number ( 53) as an
independency country on the third of November 1932 . he died peacefuliy after Iraq's
indepence.

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