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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 Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
محاولة لصياغة برنامج تمويلي متكامل لدعم المشروعات الصغيرة والمتوسطة في العراق
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تعمل البنوك والمؤسسات المالية كوسيط مالي بين أصحاب المدخرات والودائع من جهة ومستخدمي هذه الأموال من جهة أخرى، وممارسة هذه الوساطة المالية بين الطرفين توضح العلاقة التي ينشأ عنها الائتمان، فالائتمان علاقة بين طرفين أولهما تزيد موارده على احتياجاته وهم (المدخرون) والثاني تزيد احتياجاته على موارده وهم (المقترضون)، وطبيعة العلاقة التي تنشأ بينهما تأخذ أحد شكلين: مباشر دون وساطة من أي طرف خارجي، أو غير مباشر عن

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Publication Date
Sun Mar 31 2024
Journal Name
Iraqi Journal Of Political Science
Terrorist organizations employ technological development to threaten international security and stability
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Technological development intersects with terrorism to a large extent, beyond the use of the Internet and social media, in order to spread ideas, obtain support and financing, and recruit new elements, to the area of tactics and techniques of terrorist attacks, and everything related to the arsenal of terrorist weapons in the present and future, while technology offers many benefits. In various fields, and contribute to achieving multiple gains for humanity, they provide extremist and terrorist organizations and elements with a set of weapons and means through which they attempt to bypass monitoring and control efforts and the restrictions imposed on the use of weapons. They also help in planning and implementing their terrorist operations,

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Publication Date
Sun Jul 17 2022
Journal Name
Al–bahith Al–a'alami
Employing; Health Awareness, Health Awareness Announcements: (A research takenfrom a master’s degree thesis)
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The goal of health awareness is to familiarize people with health information and facts, and make them realize their sense of responsibility towards their health and the health of others.   And translate that goal in practice through applying healthy and sound behaviors spontaneously. This, the goal, is pursued by health awareness announcements through employing announcement persuasion of health as one of the methods of influencing the masses to adopt ideas, behaviors, and adherence to health advice and guidelines; The study aims to analyze the content of the Ministry of Health and Environment announcements regarding health awareness and to reveal the most employable persuasions in health awareness announcements

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Publication Date
Tue Jan 05 2010
Journal Name
Political Sciences Journal
دور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي
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دور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي

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Publication Date
Tue Dec 01 2020
Journal Name
Al-khwarizmi Engineering Journal
Applying Trade-off Curve to Support Set-Based Design application at an Aerospace Company
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Companies compete greatly with each other today, so they need to focus on innovation to develop their products and make them competitive. Lean product development is the ideal way to develop product, foster innovation, maximize value, and reduce time. Set-Based Concurrent Engineering (SBCE) is an approved lean product improvement mechanism that builds on the creation of a number of alternative designs at the subsystem level. These designs are simultaneously improved and tested, and the weaker choices are removed gradually until the optimum solution is reached finally. SBCE implementations have been extensively performed in the automotive industry and there are a few case studies in the aerospace industry. This research describe the use o

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Publication Date
Fri Jan 01 2010
Journal Name
Journal Of The College Of Languages (jcl)
El color como símbolo literario En (Cañas y Barro) de Vicente Blasco Ibáñez
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            El color es uno de los elementos novelísticos que ayudan los autores para desarrollar las acciones y llevarlas al desenlace adecuado. Y Blasco Ibáñez depende al color para pintar las escenas artísticas dentro sus novelas, especialmente, sus novelas que pertenecen al siglo de naturaleza. Él conocido con la abundancia de los colores para describir el ambiente y los personajes, como indica el autor catedrático José A. Balseiro:

  "su pluma no supo__ como el pincel de los primitivos__ del matiz logrado a toques mínimos, pacientes. ¿No era, a caso, coterráneo de Joaquín Sorolla, en cuya paleta mediterránea celebrábase, día tras día, el milagro del f

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
آليات حوكمة الشركات التي تؤثر في اتخاذ المدقق الداخلي للقرار الاخلاقي
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اصبح لمجالس الادارة في الشركات دوراً حاسماً في تعزيز الحوكمة الفاعلة، كونها تتحمل المسؤولية النهائية عن نظم الرقابة الداخلية في شركاتها، ويلعب التدقيق الداخلي دوراً اساسياً في مساعدة تلك المجالس على القيام بمهمات الحوكمة. ولهذا يبذل مجمع المدققين الداخليين الامريكي جهداً كبيراً في توجيه اعضاءه ليكونوا متخصصين في اصول حوكمة الشركات وتحسين وتقوية اخلاقيات العمل وسلامة المنظمة.

لذا فإن ا

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Publication Date
Wed May 01 2019
Journal Name
Journal Of Engineering
Reduced Complexity SLM Method for PAPR Reduction
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In this paper, the computational complexity will be reduced using a revised version of the selected mapping (SLM) algorithm. Where a partial SLM is achieved to reduce the mathematical operations around 50%. Although the peak to average power ratio (PAPR) reduction gain has been slightly degraded, the dramatic reduction in the computational complexity is an outshining achievement. Matlab simulation is used to evaluate the results, where the PAPR result shows the capability of the proposed method.  

 

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Publication Date
Wed Jan 11 2017
Journal Name
Journal: Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of some Metal Complexes with (3Z ,5Z, 8Z)-2-azido-8-[azido(3Z,5Z)-2-azido-2,6- bis(azidocarbonyl)-8,9-dihydro-2H-1,7-dioxa-3,4,5- triazonine-9-yl]methyl]-9-[(1-azido-1-hydroxy)methyl]-2H1,7-dioxa-3,4,5-triazonine – 2,6 – dicarbonylazide(L-AZ) .
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The reaction of LAs-Cl8 : [ (2,2- (1-(3,4-bis(carboxylicdichloromethoxy)-5-oxo-2,5- dihydrofuran-2-yl)ethane – 1,2-diyl)bis(2,2-dichloroacetic acid)]with sodium azide in ethanol with drops of distilled water has been investigated . The new product L-AZ :(3Z ,5Z,8Z)-2- azido-8-[azido(3Z,5Z)-2-azido-2,6-bis(azidocarbonyl)-8,9-dihydro-2H-1,7-dioxa-3,4,5- triazonine-9-yl]methyl]-9-[(1-azido-1-hydroxy)methyl]-2H-1,7-dioxa-3,4,5-triazonine – 2,6 – dicarbonylazide was isolated and characterized by elemental analysis (C.H.N) , 1H-NMR , Mass spectrum and Fourier transform infrared spectrophotometer (FT-IR) . The reaction of the L-AZ withM+n: [ ( VO(II) , Cr(III) ,Mn(II) , Co(II) , Ni(II) , Cu(II) , Zn(II) , Cd(II) and Hg(II)] has been i

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Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Argon plasma needle source
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Non thermal argon plasma needle at atmospheric pressure was generated. The experimental set up is based on very simple and low cost electric components that generate electrical field sufficiently high at the electrodes to ionize various gases, which flow at atmospheric pressure. The high d.c power supply is 7.5kV peak to peak, the frequency of the electrical field is 28kHz, and the plasma power less than 15W. The plasma is generated using only one electrode. In the present work the voltage and current discharge waveform are measured. Also the temperature of the working Ar gas at different gas flow and distances from the plasma electrode tip was recorded

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