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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
Mon Dec 20 2021
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
MORPHOLOGY AND MOLECULAR IDENTIFICATION OF THE LARVAL STAGE OF TWO SPECIES FROM THE GENUS CHRYSOBOTHRIS ESCHSCHOLTZ, 1829 (COLEOPTERA, BUPRESTIDAE)
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The genus of Chrysobothris Eschscholtz, 1829 is one of the most diverse and widespread genera of the family Buprestidae of some 700 described species distributed throughout the world. In Iraq, particularly in the Kurdistan region, about 4 species had been recorded so far, many of these species are sympatric, share larval host plants, and are difficult to reliably separate morphologically. The current study investigates species limits and relationships among the recognized species occurring within the Erbil Province; mitochondrial cytochrome C oxidase (COX I) molecular analysis confirmed the monophyly of two Chrysobothris species, Ch. affinis (Fabricius, 1794) and Ch. chrysostigma (Linnaeus, 1758). Implications of the resultant larval mor

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Publication Date
Fri Jan 01 2021
Journal Name
Aip Conference Proceedings
Preparation and characterization of mawsonite Cu6Fe2SnS8 [CFTS] thin films via the semi-computerized spray pyrolysis technique for photovoltaic applications
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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Impact the quality of the food in the rates of malnutrition in the city of Baghdad and Baquba - Iraq
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This research aims to identify the nutritional status of the individual's relationship to malnutrition using anthropometric measurements such as weight, height and impact on the values ??of the blood study sample included 200 male and 200 female of the inhabitants of the cities of Baghdad and Baquba reviewers Central Mahtbrat

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Publication Date
Fri Apr 30 2021
Journal Name
Onkologia I Radioterapia
The prevalence of lymph proliferative disorders in a group of Iraqi patients and its relation to blood indices parameters
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Abstract: Lymphoproliferative Disorders (LPDs) are a group of neoplasms affecting various cells within lymphoid system. Each type has different treatment a..70619

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Publication Date
Tue Jan 01 2013
Journal Name
Asian Journal Of Management Research
The influence of human resources management practices, and government’s role in the organizational performance of small businesses in Malaysia
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This study tries to examine a model involving human resources management practices, employees’ outcomes, governmental support, and organizational performance of small businesses in Malaysia. It was hypothesized that HRM practices will be positively related to the organizational performance (financial and operational), and that employees’ outcomes would serve as a mediator in the relationship between HRM practices and performance. Also it was hypothesized that the governmental support will be positively related to organizational performance. The statistical results on data gathered from a sample of 265 small manufacturing businesses will demonstrate the nature of relationships among the study variables. Theoretical and practical

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Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Strategic dimension for theory of constraints and its impact in decision making: بحث تطبيقي في الشركة العامة للصناعات الجلدية
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The research illustrated that the theory of constraints is   "A group of concepts and basics that aim at helping the management in order to determine the difficulties and how to overcome these difficulties through determining the necessary change and how these change can be done efficiently and effectively ".

       The research showed that the theory of constraint including its tools calls for magnifying throughput, constricting the product cycle , determining  the optimal production mix , utilization of scare resources and canceling the idle time , that achieving  throughput  increasing  then  increasing  profit .

      Moreov

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Publication Date
Sun Sep 02 2012
Journal Name
Baghdad Science Journal
Testing the ability of Porcellionides pruinosus (Brandt 1833) Isopoda Crustaceans to decompose and consume cellulosean wastes in different ecosystems
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The present study was undertaken to use individual terrestrial crustacean from Isopoda such as the species Porcellionides pruinosus (Brandt 1833) as environmental cleaner and that through the test of their abilities in decomposition of residues of some cellulosean wastes such as wood pieces which contain high ratio of urban wastes, and residue of Zea mays and particularly leaves as plant waste in agricultural fields and residue of Cynodon dactylon plants which compose the main wastes in most of gardens and parks. Experiments were conducted relatively in stable laboratory conditions to ensure environmental conditions similar to crustaceans' life. The results showed presence of good efficiency of these individuals in treating such wastes as

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Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The psychological, social and academic problems that encounter students of college of education in Al-Anbaar University /Al-qaim
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The study aims to identify the psychological, social, and academic problems that encounter students at the college of education. To this end, the researcher utilized the descriptive approach, where a questionnaire was used as a tool to collect the study data. The findings of study revealed that the main academic problems are inability to understand what the students read, lack of concentration over the process of studying. The Difficulty of preparation for test. Lack of ability to memorize quickly. As for the prominent social problems: the excessive usage of social media that drove students away from their main tasks, the Lack of participation in social activities, the scarcity the religious information. The psychological problems includ

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Publication Date
Fri Jan 11 2019
Journal Name
Iraqi Journal Of Physics
Assessment of natural radioactivity levels and annual equivalent doses in some milk powdered samples for adults used in Baghdad
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In this paper the specific activity of 238U, 232Th and 40K
radionuclides were determined by sodium iodide enhanced by
thallium NaI(Tl) detector and assessment the annual effective dose
in samples of powder milk from different companies such as
Almunaish, Seven Caw, Molty and Altunsa for adult available in
Baghdad markets. The specific activity of 40K has the greater value in
all the samples which is in the range of allowed levels globally that
suggested by UNSCEAR. The mean value of annual effective doses
were 0.121, 0.314775 and 0.305 mSv/y for 238U, 232Th and 40K
respectively.

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Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Weightings of Imam Ibn al-Mundhir               In his middle book in Sunan, unanimity and difference - the book of prayer
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The Imam Ibn al-Mundhir is likely in Shafi'i school. He has outlined some issues and disagreed with his doctrine. And that the vocabulary on which he relied on the weighting is correct and correct and I choose which I say. One of the most likely issues is the delay of Isha prayer to the darkness. And other issues simplified in the folds of research and study.

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