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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
Tue Jun 15 2021
Journal Name
Al-academy
The semiotic of the Islamic blazon - a related analytical study between the Islamic blazon and its publicity message: رغده بنت فيصل بن خضر الدعواني
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This study discusses the semiotic of the Islamic blazon - a related analytical study between the Islamic blazon and its visual publicity message. The aim of the current study is to explore the related relationship between the Islamic blazon and its visual publicity message. The sample is contained Five of Islamic blazon in the Mamelukes period which is between 1250 to 1517. The methodology is descriptive-analytical, and the result is that there is a clear relation between the Islamic blazon with its visual publicity message. This study's recommendation is to go towards analyzing the meanings of the cultural legacies of the Islamic civilization, and researching the implicit meanings accompanying these features leads to a deeper understand

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Publication Date
Wed May 01 2024
Journal Name
Journal Of Physics: Conference Series
A study of the Electrical and Dialectical proprieties of S<sub>60-</sub>Se<sub>40-X</sub>-Pb<sub>X</sub>Chalcogenide Compound
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Abstract<p>In this study, the melting-cooling method was used to prepare the chalcogenide compound S<sub>60</sub>-Se<sub>40-X</sub>-Pb<sub>X</sub>. Four samples were obtained by partial replacement of Selenium with Lead in the weight ratios x = 0, 10, 20, and 30, respectively. The materials were mixed separately, ground, placed in quartz ampoules, and heated to 500 degrees Celsius. After conducting several operations on the samples, their insulating properties were studied, represented by the real dielectric constant and the imaginary dielectric constant, and the electrical conductivity was measured as a function of the frequency. It was found that partial replacement plays an impo</p> ... Show More
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Publication Date
Tue Feb 08 2022
Journal Name
South Asian Journal Of Social Sciences And Humanities
The Impact of University Leadership and the University Organizational Environment on the Performance of staff: A Case Study at Al Maaqal University (Private Sector)
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This study aims to explore the impact of the interaction of the university leadership and the university organizational environment on the performance level of the staff at Al-Maaqal university. This university was chosen as a field of study because it is a new university and needs studies that develops and contributes to improve its overall performance. The problem defined by the following question: to what extent does the interaction of the university leadership and the university organizational environment affect the performance level of the teaching staff at AlMaaqal University?). The method of this study adopted a major hypothesis in which there is a statistically significant effect of university leadership and university environment o

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Publication Date
Thu Oct 12 2017
Journal Name
Iraqi Journal Of Laser
A Comparative Evaluation of Post-Operative Pain and Function after Gingival Depigmentation Using 940 Nm Diode Laser And Conventional Bur Method: 6 Months Study
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The aim of the study was to evaluate the efficacy of diode laser (λ=940 nm) in the management of gingival hyperpigmentation compared to the conventional bur method. Materials and methods: Eighteen patients with gingival hyperpigmentation were selected for the study with an age between 12-37 years old. The site of treatment was the upper gingiva using diode laser for the right half and the conventional method for the left half. All patients were re-evaluated after the following intervals: 3 days, 7 days, 1 month and 6 months post-operation. Pain and functions were re-evaluated in each visit for a period of 1 day, 3 days and 1 week post-operation. Laser parameters included 1.5 W in continuous mode with an initiated tip (400 μm) placed in

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Publication Date
Mon Jun 13 2022
Journal Name
International Journal Of Health Sciences
Iraqi EFL teachers, supervisors and students’ perception of CLT principles and practices at Iraqi schools: A study of its benefits, snags, and future directions
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Even though in recent decades a bulk of studies have been accomplished on the use of communicative language teaching (CLT) in English as a foreign language (EFL) environments, fairly a limited numbers of studies precisely dealt with investigating the attitudes of language teachers, students and supervisors concerning the principals of CLT in the context of Iraq. Henceforth, this study was designed to delve into the attitudes of teachers, learners and supervisors about the implementation. To this end, the study was accomplished using a mixed method design. The present study was carried out in two phases: designing and using a questionnaire plus interviewing the teachers, students and supervisors (51 language learners, 41 teachers and

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Job enrichment, knowledge capital and its impact on strategic success: exploratory study at a sample of the Iraqi government and Private Colleges on Baghdad
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The problem of research was the lack of research that dealt with issue of the job design approach that is more suitable for knowledge work, therefore, the research aims to determine the impact of job enrichment,  and knowledge capitalon strategic success, starting from the hypothesis that there significant impact of job enrichment and knowledge capital on strategic success, to achieve this goal the researchers from the theoretical literature and  related studies conclude to the construction of the scheme shows the hypothetical relationship between the variables, which was adopted job enrichment as independent variable while knowledge capital plays two roles, the first as an independent variable and the second as an intermediate

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Publication Date
Tue May 30 2023
Journal Name
Dirasat: Human And Social Sciences
The Family of Minister Al-Sayyid Al-Ajall: A Study of Its Political, Administrative, and Urban Role (7th-8th Century AH / 13th-14th AD)
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Objectives: The study aimed to clarify the role of Al-Sayyid Al-Ajall and his family in the service of the Mongol Empire. They worked to develop its administrative and military institutions, benefiting from their extensive experience in administration, politics, economics, and urban affairs. Due to their capabilities, they received the patronage of Genghis Khan and subsequent generations, earning the confidence of the ruling Mongol authority. As a result, they were granted significant powers within the state.       Methods: The study relied on the analytical method to analyze historical texts, compare them with others, and discuss them accurately. Results: The study yielded several results, including the minister's keen interes

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Publication Date
Mon Nov 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Strategic leadership skills as a moderate of the impact of environmental challenges on effective management of the environment according to the model (VUCA Prime)
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Purpose – The main purpose of this research is to highlight the main role of strategic leadership skills for top managements in accessing to effective management in accordance with the (VUCA Prime) methodology in (VUCA) environment as Miniature virtual environment, which refers to (Volatility), (Uncertainty), (Complexity), and (Ambiguity).

methodology – To achieve the research objective, this study selected the quantitative approach in research design, Questionnaire was used as the main instrument for data collection, the sample comprised the opinion poll (106) individual who functions as a head department. (Structural equation modelling by (Smart Pls3)

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Publication Date
Sat Dec 28 2024
Journal Name
Journal Of Physical Education
The Effect of a Psychological Counseling Program to reduce irrational ideas and the causal attribution of the coaches of the gymnasium sports care center
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The research aimed to prepare a psychological counseling program for the coaches of the Sports Care Center in the gymnasium, and to learn about the impact of the psychological counseling program in reducing irrational ideas and causal attribution of the coaches of the Sports Talent Care Center in the gymnasium, to assume that there are statistically significant differences between the results of the tribal and posttests of the research group Experimental in the scale of irrational ideas, and there are statistically significant differences between the results of the tribal and posttests of the experimental research group in the scale of the causal attribution scale, The experimental approach was adopted by designing one experimental

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Publication Date
Sun Jan 14 2018
Journal Name
Journal Of Engineering
The effect of Laser Shock Peening on Fatigue Life Using Pure Water and Hydrofluoric Acid As a Confining Layer of Al – Alloy 7075-T6
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Laser shock peening (LSP) is deemed as a deep-rooted technology for stimulating compressive residual stresses below the surface of metallic elements. As a result, fatigue lifespan is improved, and the substance properties become further resistant to wear and corrosion. The LSP provides more unfailing surface treatment and a potential decrease in microstructural damage. Laser shock peening is a well-organized method measured up to the mechanical shoot peening. This kind of surface handling can be fulfilled via an intense laser pulse focused on a substantial surface in extremely shorter intervals. In this work, Hydrofluoric Acid (HF) and pure water as a coating layer were utilized as a new technique to improve the properti

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