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Melting Enhancement in a Triple-Tube Latent Heat Storage System with Sloped Fins
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Due to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions through the inner and the outer tubes. Various configurations, dimensions, and orientations of the circular fins at different flow conditions of the heat-transfer fluid were numerically examined and optimized using an experimentally validated computational fluid-dynamic model. The results show that the melting rate, compared with the base case of finless, can be improved by 88% and the heat charging rate by 34%, when the fin orientation is downward–upward along the left side and the right side of the PCM shell. The results also show that there is a benefit if longer fins with smaller thicknesses are adopted in the vertical direction of the storage unit. This benefit helps natural convection to play a greater role, resulting in higher melting rates. Changing the fins’ dimensions from (thickness × length) 2 × 7.071 mm2 to 0.55 × 25.76 mm2 decreases the melting time by 22% and increases the heat charging rate by 9.6%. This study has also confirmed the importance of selecting the suitable values of Reynolds numbers and the inlet temperatures of the heat-transfer fluid for optimizing the melting enhancement potential of circular fins with downward–upward fin orientations.

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Publication Date
Wed Apr 01 2015
Journal Name
Journal Of Educational And Psychological Researches
Analysis of Palestinian Ministry of Education Test Results in Mathfor Eighth Graders basic Public Schools in Tulkarm
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هدفت هذه الدراسة إلى تحليل نتائج الاختبار الوطني الموحد الذي تطبقه وزارة التربية والتعليم الفلسطينية في مادة الرياضيات لطلبة الصف الثامن الأساسي في المدارس الحكومية في محافظة طولكرم، وذلك لمعرفة مستوى الطلبة على هذا الاختبار في ضوء متغيرات الجنس والمنطقة التعليمية ونوع المدرسة، ومعرفة علاقة التحصيل على هذا الاختبار بتحصيل الطلبة المدرسي والمعدل العام. ولتحقيق ذلك تم تحليل درجات (3218) طالباً وطالبة؛ وهم ي

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Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Knowledge Upgrading on Business Continuity:A Field Research in Private Colleges and Universities in Baghdad
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The research aims to study the effect of knowledge upgrade on business continuity in private colleges and universities in Baghdad. The research problem is summarized in the main question (were the academic leaders able to employ knowledge upgrading to enhance business continuity). The most important of this sector were the universities and the private college in the city of Baghdad as a field for this research, the researchers conducted a field visit to (10) universities or private colleges, the research sample consisted of (177) individuals from the deans of colleges and their assistants, as well as heads of scientific and administrative departments. The data was analyzed and the hypotheses were tested using the appropriate statistical

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Publication Date
Tue Mar 28 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Phytochemical Study of Steroidal Sapogenin “Tigogenin” Present in the Leaves of Yucca aloifolia Cultivated in Iraq
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This study detects the presence of the most important steroidal sapogenin “Tigogenin” in the leaves of Yucca aloifolia widely cultivated in Iraq. The absence of any study concerning the Tigogenin content of this medicinal plant in Iraq, and the industrial importance of Tigogenin depending on its role as a precursor in the synthesis of some steroidal drugs, acquired this study its value. This study concerned with extraction, identification, isolation, and purification of Tigogenin from the leaves of Yucca aloifolia. Extraction of this compound was carried out using two methods. Identification of this compound was done using thin layer chromatography (TLC) where different solvent systems had been tried. Liberm

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Publication Date
Sat Feb 01 2014
Journal Name
American University Of Sharjah (aus) "second International Conference On Sustainable Systems And The Environmental (isse14)
Correlating BOD5 and COD of Sewage in Wastewater Treatment Plants; Case study Al- Diwaniyah WWTP in Iraq
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This study aims to establish an empirical correlation between biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) of the sewage flowing in Al-Diwaniyah wastewater treatment plant. The strength of the wastewater entering the plant varied from medium to high. High concentrations of BOD5 and COD in the effluent were obtained due to the poor performance of the plant. This was observed from the BOD5 /COD ratios that did not confirm with the typical ratios for the treated sewage. To improve the performance of this plant, regression equations for BOD5 and COD removal percentages were suggested which can be used to facilitate rapid effluent assessment or optimal process control. The equations relating the percentage removal of

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of e-learning standards in auditing in auditing the performance of customer capita: applied research
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                  In light of the corona pandemic, educational institutions have moved to learning and teaching via the Internet and e-learning ,and this is considered a turning  point in course of higher education in Iraq in particular and education in general, which generated a great challenge for educational institutions to achieve the highest possible levels in practices and processes to reach the highest quality of their outputs from graduate students to the labor market that auditing performance by adopting e-learning standards is one of the effective tools that help the management of educational institutions by providing information on the ex

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Publication Date
Thu Apr 01 2021
Journal Name
Biochem. Cell. Arch.
Role of Spraying Potassium Fertilizer Types in Improving of flag Leaf Contribution in Grain Yield of Wheat
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A field experiment was carried out during winter season of 2019 at Al-Muradiya research state, Babylon government, Iraq, to study the role of the sprayed types of potassium fertilizer in improving of flag leaf contribution in grain yield of wheat. The layout of the experiment was randomized complete block design in factorial arrangement at three replicates. The experiment included spraying common and nano potassium fertilizer at booting stage, in addition to control treatment (spraying of distilled water) as a first factor, and removal treatments (removal of flag leaf at 10% anthesis stage and nonremoval) as a second factor. The results showed that the spraying of nano potassium fertilizer was significantly superior in the dry matter transp

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Scopus
Publication Date
Thu Feb 03 2022
Journal Name
Open Access Macedonian Journal Of Medical Sciences
Femtosecond Small Incision Lenticular Extraction in comparison to Femtosecond Laser In situ Keratomileusis Regarding Dry Eye Disease
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 Abstract Objective: Comparison of femtosecond small incision lenticule extraction (FS-SMILE) versus Femtosecond laser Insitu keratomileusis (FS-LASIK) regarding dry eye disease (DED) and corneal sensitivity (CS) after those refractive surgeries. Methods: A comparative prospective study conducted for a period of 2 years; from March 2017 until February, 2019. Enrolled patients were diagnosed with myopia. Fifty patients (100 eyes) were scheduled for bilateral FS-SMILE and the other 50 patients (100 eyes) had been scheduled for bilateral FS-LASIK. Both groups were followed for six months after surgery. The age, gender, and preoperative refraction for both groups were matched. Complete evaluation of dry eye disease had been

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Crossref
Publication Date
Sun Jul 07 2013
Journal Name
Journal Of Educational And Psychological Researches
Effect of Using Computer in Getting and Remaining Information at Students of First Stage in Biology Subject
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Effect of Using Computer in Getting and Remaining Information at Students of First Stage in Biology Subject MIAAD NATHIM RASHEED LECTURER Abstract The recent research goal is to know the influence of computer use to earn and fulfillment information for students of first class in biology material and to achieve that put many of the zeroing hypothesis by researcher as follow: There were no differences between statistical signs at level (0,05) between the average students' marks who they were study by using computer and between the average student ' marks who they were study in classical method of earning and fulfillment. The researcher chose the intentional of the medical technical institute that included of two branches the first class (A

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Publication Date
Mon Dec 24 2018
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
MINERALOGY AND GEOCHEMISTRY OF CORAL REEF IN IRAQI MARINE ENVIRONMENT IN THE NORTH PART OF ARABIAN GULF
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    Coral reef area in northwest of the Arabian Gulf was investigated for mineralogy and geochemistry to throw lights on such unique Iraqi Marine Environment; six specimens of two main species of coral reefs, Platygyra pini Chevalier, 1975 and Octocoral Menella were collected at two sites. While eight samples of the surrounding sediments are chosen from other two sites. The mineralogy is determined by XRD, and reveals that calcite, low magnesium-calcite, and aragonite are the main minerals that comprise the Octocoral Menella in site 1, whilst aragonite and calcite are dominate in the P. pini coral reef at site 4.

    The non–carbonate fractions indicate that thes

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Publication Date
Mon Sep 30 2019
Journal Name
College Of Islamic Sciences
Loqmania commandments in the Koran And its impact in the refinement of the doctrine and morals emerging
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Luqman's story stated that human instinct, if I was brought up properly, reaches wisdom and inflicts the right to everything. It is to go to worship God and adhere to the satisfaction of morals and high morals that are ordered to meet among human beings in this life, because this worship educates in the soul the most beautiful morals needed by human beings of honesty, honesty and modesty, and the work of good and virtues, and distancing the soul from evil and vices.

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