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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
Thu Mar 01 2018
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Addition of Combination of Plasma Treated Polyester and Polyamide Fibers on Surface Roughness and Some Mechanical Properties of Heat Cured Acrylic Resin
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Publication Date
Sun May 10 2015
Journal Name
Al-academy
The system and Disorder of shape and content in Interior Design Educational halls in the Ministry of Labor and Social Affairs (Analytical study): رجاء سعدي لفتة
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Dealing with this study to find a link principle in the construction of the system and disorder to the promise of the principles and concepts of intellectual and philosophical form and content in the act of interior design of the halls education in the Ministry of Labor and Social Affairs , which leads to a reaction design objective and functionally and to increase the strength of the effect on users of the coaches and trainers . As it informs the side cognitive and developmental study of the design of the interior spaces . So it was the goal of research in the detection of the nature of the system and disorder with Focus indicators and the type of regulations and privacy and what constitutes the framework of knowledge in order to explai

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Publication Date
Mon Feb 13 2023
Journal Name
Journal Of Educational And Psychological Researches
Patterns of Feedback Used in the E-Learning System from the Teachers of the First Cycle in the Governorate of Muscat at the Sultanate of Oman
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Abstract

This study aims to identify the degree to which the first cycle teachers use different feedback patterns in the e-learning system in addition to the differences in the degree of use according to specialization, teaching experience, and in-service training in the field of classroom assessment, as well as the interaction between them. The study sample consisted of (350) female teachers of the first cycle in government schools in Muscat Governorate for the academic year 2020/2021. The study used a questionnaire that contained four different patterns of feedback, which are reinforcement, informative, corrective, and interpretive feedback. The psychometric properties of the que

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Publication Date
Mon Jan 18 2021
Journal Name
Iraqi Journal Of Science
The Policy of Integration in Developing The Skills of People with Special Needs Through A Professional Didactic Approach “Analytical Field Study on the Reality of Integrated Classes in Azrou City”
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In view of the importance of the educational act, and the effective role played by the school in building the society on the basis of solidarity and equal opportunities, as well as the rehabilitation of emerging generations to exercise their rights and duties, as well as integration into the world of knowledge, communication and in different social and environmental circles[1]. The process of integrating special needs children, in regular or integrated classes within regular public schools or specialized rehabilitation educational centers, is of great importance to these groups of society, their families and society in general[2]. Based on the above, the research will start by answering the followingquestions:

How can the parents

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Electronic trading system and its refletion in the trading of stock market indices –an analytical study of the Iraqi market for securities–
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The research aims at identify the role of the electronic trading system used in the Iraq stock exchange to promote trading activity for the stocks of listed companies in this market.

To prove the hypothesis of research, it was selected the main trading indicators for the market to be a main field in test the research hypothesis.it was selected as the period of time for (9)years span between the years (2005-2013) because they represent the first two articles of equal time periods represent aperiod that preceded the introduction of electronic trading system  while the second represents the period of time that followed 

The research found a number of conclusions but the mo

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Publication Date
Wed Oct 28 2020
Journal Name
Iraqi Journal Of Science
Qualitative and Quantitative Studies of the Effects of Spherical Aberration on the Optical System in the Cases of Coherent and Incoherent Illumination
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In this paper, we study the effects of coherent and incoherent illumination on the optical imaging system. The effects were studied qualitatively in terms of Point Spread Function (PSF) and Modulation Transfer Function (MTF), and quantitatively in terms of Root Mean Square Error (RMSE). Different values of radius of aperture were investigated in the presence and absence of spherical aberration with various magnitudes of spherical aberration (M=1, 2, and 3). The experiments were performed using homogeneous media.

     The results show that imaging with incoherent illumination is better than imaging with coherent illumination, especially for small aperture. Also, we found that the effects of spherical aberration

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Publication Date
Wed Sep 16 2020
Journal Name
Route Educational & Social Journal
Effect of applying the QR-Code system for acquisition chemistry and creative thinking in of first class female student at intermediate schools.
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This research aims at identifying the system of applying the QRcode system for acquisition of chemistry by first class female students studying at intermediate schools knowledge and its effect on creative thinking. The research sample consisted of (63) female students in one of the intermediate schools in Baghdad/Iraq using two equivalents experimental and control groups. The scientific context used was based on the chemistry text book related to the periodic table, (Metals) for the first group of students and Alkaline metals,Nonmetals, Metalloides) for the second group. The research methodology employed consisted of the followings :Measuring students acquisition using (35) issues. The results were verified for their face validity and obtai

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Publication Date
Mon Jan 01 2018
Journal Name
Matec Web Of Conferences
Investigation of surface area of lakes and marshes from satellite images by using remote sensing and geographic information system integration in Iraq
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Water level and distribution is very essential in almost all life aspects. Natural and artificial lakes represent a large percentage of these water bodies in Iraq. In this research the changes in water levels are observed by calculating the areas of five different lakes in five different regions and two different marshes in two different regions of the country, in a period of 12 years (2001 - 2012), archived remotely sensed images were used to determine surface areas around lakes and marshes in Iraq for the chosen years . Level of the lakes corresponding to satellite determined surface areas were retrieved from remotely sensed data .These data were collected to give explanations on lake level and surface area fluctuations. It is imp

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Publication Date
Sat Oct 01 2022
Journal Name
Colloids And Surfaces A: Physicochemical And Engineering Aspects
Application of natural deep eutectic solvents in bulk liquid membrane system for removal of free glycerol from crude fatty acid methyl ester
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Fatty Acid Methyl Ester (FAME) produced from biomass offers several advantages such as renewability and sustainability. The typical production process of FAME is accompanied by various impurities such as alcohol, soap, glycerol, and the spent catalyst. Therefore, the most challenging part of the FAME production is the purification process. In this work, a novel application of bulk liquid membrane (BLM) developed from conventional solvent extraction methods was investigated for the removal of glycerol from FAME. The extraction and stripping processes are combined into a single system, allowing for simultaneous solvent recovery whereby low-cost quaternary ammonium salt-glycerol-based deep eutectic solvent (DES) is used as the membrane phase.

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Clinical And Experimental Dentistry
Comparison of the accuracy of intraoral digital impression system and conventional impression techniques for multiple implants in the full-arch edentulous mandible
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