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Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material
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In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant air mass flow rate of (0.0375 kg/sec). The parameters that affect the thermal performance of the SAH with and without the PCMs presented by solar radiation, the difference in air temperature, outlet air temperature, instantaneous thermal efficiency, and daily efficiency are evaluated. The experimental results show that when using the PCM, the temperature of the outlet air was enhanced and increased over the ambient temperature by (1.5 - 6.5 C) after sunset for 5 hours period. It was found that the instantaneous thermal efficiency of the heater using thermal storage exceeds 100% after sunset, this is due to a large amount of heat stored in the paraffin wax that has been released during the discharge process. Also, it was found that the daily efficiency of the double pass SAH integrated with and without thermal energy storage unit was (56, 47%) respectively.

 

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Publication Date
Sun Oct 01 2023
Journal Name
Baghdad Science Journal
Evaluation of the cytotoxic effects of the colchicine compound isolated from the leaves of Calotropis procera (Ait) against MCF-7 and SK-GT-4 cancer cell lines.
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Alkaloids are regarded as important nitrogen-containing chemical compounds that serve as a rich source for discovering and developing new drugs where most plant-origin alkaloids have antiproliferation effects on different kinds of cancers. Alkaloids’ continence of Calotropis procera leaves are detected by two biochemical alkaloid reagents. Also GC-MS analysis for leaf alkaloid extract was done that showed the existence of one type of alkaloid compound at retention time12.8min detected as colchicine (C22H25N06( by comparing it with colchicine standard reference (Sigma Aldrich) with M.wt 399g/mol and percentage area 7.1%. Furthermore, identification, separation, and purification

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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
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
Suspicion in the truth that the satisfaction of the student in the criticism of the speech of the poet and the writer to I bin Al-Atheer
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Suspicion in the truth that the satisfaction of the student in the criticism of the speech of the poet and the writer to I bin Al-Atheer

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Publication Date
Wed Jun 30 2021
Journal Name
Gsc Biological And Pharmaceutical Sciences
Differences in some cranial bones between two Cyprinidae species, Common carp Cyprinus carpio (Linnaeus, 1758) and Crucian Carp Carassius carassius (Linnaeus, 1758) Collected from Tigris River, Iraq
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The present study attempts to identify some of the differences between the skull bones of two species Cyprinus carpio and Carassius carassius, which belong to the Cyprinidae family. The study is a taxonomic diagnostic study between the two species which are considered local fish abundant in the Iraqi aquatic environment

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Challenges of applying IFRS 16 to the Iraqi environment and its role in improving Financial indicators of economic units Applied to the General Company of Iraqi Airways
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Abstract

The leases, are regarded as one of the most controversial accounting issues in recent years, since they  represents one of the important sources of funding, which may be exploited by the tenant as off- Balance sheet Financing , which negatively affects the quality of financial reporting. The Financial Accounting Standards Board (FASB) and the International Accounting Standards Board (IASB) have "significant" interest in accounting for leases . FASB issued Statement of Financial Accounting Standards 13 on lease contracts in 1976 and IASB issued IAS 17 in 1980, which was amended in 1997 and IFRS 16, issued in January 2016, which will be effective on January 1, 2019 , to solve

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Publication Date
Wed Feb 01 2023
Journal Name
Journal Of Engineering
Applying the WaterGEMS Software to Conduct a Comparison of the Darcy-Weisbach and Hazen-Williams Equations for Calculating the Frictional Head Loss in a Selected Pipe Network
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Darcy-Weisbach (D-W) is a typical resistance equation in pressured flow; however, some academics and engineers prefer Hazen-Williams (H-W) for assessing water distribution networks. The main difference is that the (D-W) friction factor changes with the Reynolds number, while the (H-W) coefficient is a constant value for a certain material. This study uses WaterGEMS CONNECT Edition update 1 to find an empirical relation between the (H-W) and (H-W) equations for two 400 mm and 500 mm pipe systems. The hydraulic model was done, and two scenarios were applied by changing the (H-W) coefficient to show the difference in results of head loss. The results showed a strong relationship between both equations with correlation coefficients of 0.999,

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Publication Date
Wed Oct 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
knowledge strategic abilities And impact in the building of competitive advantage Field research the views of a sample of the administrative leaders of the Iraqi private banks
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The research synthesis variables of competitive advantage and the mechanism achieved by focusing on knowledge abilities and strategic of the administrative leadership, and governments and the developed countries took the racing frantically and my destiny to invest more money and resources to development of wealth and human knowledge is so choice investment winner always and who Aaikhyee never, because God Almighty give humans the abilities of all other creatures and that these abilities varying from person to person, there is the problem of search provoking questions about the essence of what it's about research and both sides theoretical and field, the objective of this research

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Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Evaluating the quality of educational services according to the modified Servqual modelStudy of a sample of students of the Faculty of Management and Economics / University of Baghdad
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The research aims to apply a modified SERVQUAL model to evaluate the quality of the educational services via conducting exploratory research for students from the College of Administration and Economics- Department of Business Administration- Evening studies at the University of Baghdad. Questionnaire of two parts was distributed to a sample of (72) students out of (720) students of the 2nd.,3rd. and 4th. year in the beginning of the second semester of the year 2008-2009 to measure the expectations and perceptions to the quality of the educational services. Five major dimensions were analyzed to see the gaps for (22) variables. The study concluded that there were (13) variables confirmed that the

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Publication Date
Wed Aug 31 2022
Journal Name
Al-kindy College Medical Journal
Antimicrobial Activity of Lepidium Sativum against Multi drug resistant and sensitive Pseudomonas aeruginosa from clinical isolates, Khartoum State, Sudan: Lepidium Sativum against Clinical isolates of Pseudomonas aeruginosa
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Background: L. sativum, are traditionally used for the treatment of various diseases and thought to have medicinal value. Isolates from many part of the world is now multidrug resistant. Therefore, there is an urgent need to look for and test an alternative herbal drug.

Objective: The present study aimed to evaluate the antibacterial activity of L. Sativum seed extract against multi drug resistant (MDR) and sensitive Pseudomonas aeruginosa clinical isolates.

Subjects and Methods: An ethanolic and aqueous stock extracts were prepared from L.  sativum seed plant then serial dilutions were prepared and the obtained concentrations (50, 25, 12.5 and 6.2 mg/ml) were tested against 30 multidrug-resistan

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Theories of the structure of modern finance : practical application of pecking order theory and the life cycle of the company/analytical research of asmple of foreign companies
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 Is the subject of the financial structure of the most important topics for which she received the interests of scientific research in the field of financial management , as it emerged several theories about choosing a financial structure appropriate for the facility and behavior change funding them , and in spite of that there is no agreement on a specific theory answer various questions in this regard , and a special issue of the financial structure optimization.

The objective of the research was to identify the most important theories of the structure of modern financial theory has been to focus on the capture of financial firms in two different stages of their life cycle , so-called growth and ma

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