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Experimental Study on the Effect of Insertion of Copper Lessing Rings in Phase Change Material (PCM) on the Performance of Thermal Energy Storage Unit
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Abstract

One of the most suitable materials to be used in latent heat thermal energy storage system (LHTES) are Phase change materials, but a problem of slow melting and solidification processes made many researchers focusing on how to improve their thermal properties. This experimental work concerned with the enhancing of thermal conductivity of phase change material. The enhancing method was by the addition of copper Lessing rings in phase change material (paraffin wax). The effect of diameter for the used rings was studied by using two different diameters (0.5 cm and 1cm). Also, three volumetric percentages of rings addition (3%, 6% and 10%) were tested for each diameter. The discharging process was done with four velocities for each case. The obtained results indicated that the maximum volumetric percentage gave a diminished time for melting and maximized the heat transfer in both PCM and air sides as compare with the case of no rings, but the effect of these rings had lower effect on the solidification time. In case of 1 cm rings diameter minimum time for melting was obtained for both 3% and 6% volumetric percentages as compared with the same percentages in case of 0.5 cm diameter rings, while the latter with 10% volumetric percentage overcomes the 1 cm diameter rings for the same previous percentage. Also it can be seen that the minimum velocity (v=1m/s) gave the utmost outlet temperature and with the maximum one (v=3m/s), the minimum solidification time achieved.

Keyword: Thermal energy storage systems, Latent heat storage, Phase change materials, Heat transfer enhancement.

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Publication Date
Wed Oct 01 2008
Journal Name
Journal Of Educational And Psychological Researches
العلاقــة بين المقرر الدراســي والتخصـص والتحصـيل العلمي في الكيميــاء والاتجــاه نحــو العـلوم لدى طلبــة كليــة التربيــة ابن الهيثــم / جامعــة بغــداد
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تهدف هذه الدراسة إلى معرفة الفرق في التحصيل الدراسي في الكيمياء والاتجاه نحو العلوم بين طلاب التخصص العلمي وطلاب التخصص الصناعي الصف الأول كلية التربية ابن الهيثم، كذلك تهدف الدراسة إلى معرفة العلاقة بين التحصيل الدراسي في الكيمياء ودرجات اختبار نهاية الفصل في الكيمياء، والمعدل التراكمي بعد أخذ المقرر الدراسي والاتجاه نحو العلوم بالنسبة لطلاب التخصص العلمي وطلاب التخصص الصناعي.

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Structural and Optical Properties for Nanostructure (Ag2O/Si & Psi) Films for Photodetector Applications
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Ag2O (Silver Oxide) is an important p-type (in chasm to most oxides which were n-type), with a high conductivity semiconductor. From the optical absorbance data, the energy gap value of the Ag2O thin films was 1.93 eV, where this value substantially depends on the production method, vacuum evaporation of silver, and optical properties of Ag2O thin films are also affected by the precipitation conditions. The n-type and p-type silicon substrates were used  with porous silicon wafers to precipitate  ±125 nm, as thick Ag2O thin film by thermal evaporation techniques in vacuum and via rapid thermal oxidation of 400oC and oxidation time 95 s, then characterized by measurement of

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Publication Date
Tue Aug 30 2022
Journal Name
مجلة واسط للعلوم الریاضیة
المناخ التنظيمي لشعب الرياضة المدرسية في أقسام الانشطة الرياضية و المدرسية لمحافظة بغداد من وجهة نظر مدرسي التربية الرياضية للمرحلة المتوسطة
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يهدف البحث الحالي إلى دراسة تأثير المناخ التنظيمي لشعب الرياضة المدرسية في اقسام الانشطة الرياضية على مدرسي التربية الرياضية لأهمية المناخ التنظيمي لما يمثله من الخصائص والسلوكيات التي يتأثر بها العاملون التي قد تتباين من مكان لآخر والبيئة الجغرافية وثقافتها النوعية وذلك باستخدام المنهج الوصفي ولتتحقق من خلال الدراسة الميدانية, يتمثل مجتمع البحث الحالي من مدرسي التربية الرياضية في مدارس محافظة بغداد وال

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Publication Date
Sun Jan 01 2017
Journal Name
مجلة علوم الرياضة في جامعة ديالى
إتخاذ القرار و علاقته بإنماط الشخصية و الإدراك البنائي لدى مدراء منتديات الشباب و الرياضة في محافظات الفرات الأوسط و الجنوبية.
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Publication Date
Sun Jan 01 2017
Journal Name
مجلة كلية الادارة والاقتصادللدراسات الاقتصادية والادارية والمالية
تصميم الترتيب الداخلي األمثل باستعمال تقنية التخصيص النسبي المحوسب للتسهيالت )CRAFT)بحث تطبيقي في الشركة العامة لصناعة الزيوت النباتية – مصنع المأمون
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The facilities layout are among the most important of the most influential factors in the efficiency of the production system, and represents the systematic layout of the various work centers, tools, persons, and other auxiliary services within the factory. Careful selection of the technique that would be used in Re-layout, represents an important step in reaching to the optimum layout that keeps on reducing handling costs and reduce unnecessary movement of materials, as well as the regularity and functioning of the flow of materials through the facilities. The research aims to propose a new layout of (Al-M'ammon Factory / The General Company for Vegetable Oils Industry), and then re-layout according to the new propose layout by using of te

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Science
Investigate and Prepare silver Nano Particles Using Jet Plasma
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Nano- particles (Ag NPs) are synthesized by using plasma Jet  argon gas. The prepared Ag NPs are characterized by Atomic Absorption Spectroscopy (AAS) The measure was performed for different time exposuring 15,30,45 and 60 sec. The results shows the low concentration of nano-silver time expose (15 sec) and very) and high concentration at 60 sec. The UV-VIS spectrometer for nano-silver different time exsposuring to plasma, shows the Surface Plasmon Resonance (SPR) appeared around 419 nm, and the  energy gab is 4.1 eV for the 15 second exposure and 1.6eV for 60 second exposure.  The Scanning Probe Microscope (SPM) is used to identify the characterization of silver  nanoparticles, the average diameter of nano-silver  for 15 second exp

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Scopus (8)
Crossref (4)
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Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
معوقات تطبيق الإدارة الإلكترونية في وزارة التربية والتعليم بسلطنة عمان(البوابة التعليمية الإلكترونية أنموذجاً) من وجهة نظر موظفي المديرية العامة لتقنية المعلومات
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Drawbacks of Implementing Electronic Management in the Ministry of Education (A sample: Oman Educational Portal) from the Point of View of IT Staff. The study aimed at discovering the drawbacks of implementing electronic management in the Ministry of Education (a sample: Oman Educational Portal) from the point of view of IT staff, and that is by answering the following questions: - What are the main drawbacks (administrative, financial, technical and drawbacks related to human resources) that hinder implementing the electronic management in the Ministry of Education (a sample: Oman Educational Portal) from the point of view of IT staff? - Are there any statistical significance differences at the level (0.05) between study samples on the

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Publication Date
Sun Mar 26 2023
Journal Name
Arab Science Heritage Journal
الاديب الكاتب والمؤرخ الفقيه يحيى بن خلدون (ت 780هـ/ 1379م) كاتب ديوان الانشاء في دولة بني زيان (633-962هـ/ 1235-1554م) بتلمسان
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    A prominent figure such as Yahya bin Khaldoun and a scholar of the moroccan countries in the medieval era, and had a special place in the history of the country and the state of Bani Zayan, and the positions he occupied in it and left his scientific, literary and historical traces, leaving him an imprint in the course of history and its events, and in this study
I dealt with the research: his personal life : his name and lineage, then his upbringing and his family.

    The aim of the study is to know this character in the details of his personal and scientific life, according to the historical descriptive research method, including description and presentation of events, and linking them in a

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Publication Date
Wed Jul 14 2021
Journal Name
The Open Civil Engineering Journal
Producing Sustainable Concrete using Nano Recycled Glass
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Background:

Many tools and techniques have been recently adopted to develop construction materials that are less harmful and friendlier to the environment. New products can be achieved through the recycling of waste material. Thus, this study aims to use recycled glass bottles as sustainable materials.

Objective:

Our challenge is to use nano glass powder by the addition or replacement of the weight of the cement for producing concrete with enhanced strength.

Methods:

A nano recycled glass p

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Publication Date
Mon Dec 30 2019
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Biodiesel production from used vegetable oil (sunflower cooking oil) using eggshell as bio catalyst
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Bio-diesel is an attractive fuel fordiesel engines. The feedstock for bio-diesel production is usually vegetable oil, waste cooking oil, or animal fats. This work provides an overview concerning bio-diesel production. Also, this work focuses on the commercial production of biodiesel. The objective is to study the influence of these parameters on the yield of produced. The biodiesel production affecting by many parameters such s alcohol ratio (5%, 10%,15 %, 20%,25%,30%35% vol.), catalyst loading (5,10,15,20,25) g,temperature (45,50,55,60,65,70,75)°C,reaction time (0-6) h, mixing rate (400-1000) rpm. the maximum bio-diesel production yield (95%) was obtained using 20% methanol ratio and 15g biocatalyst at 60°C.

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