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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
Thu Nov 08 2018
Journal Name
Arab Science Heritage Journal
براعة براعة علماء الأندلس في الزراعة من خلال مؤلفاتهم الفلاحية
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           It was the sayings of Andalusia scholars in agriculture based on experiments and theories that helped a lot in the success and development of agriculture in the Andalusia ,and also The divisions of the soil and out types and forms it helped a lot of to know arable of non-arable land earth and all off the determination of the color of repentance is important often discovered by agricultural scientists and that helped in the cultivation of certain crops in certain land without another land.and though each particular agricultural crops specific soil in which to live and not live in other soil ,

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Publication Date
Sat Nov 02 2019
Journal Name
السياسية والدولية
دور الجامعات العراقية في اعداد القيادات الشبابية لتعزيز المسؤولية المجتمعية
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تعد الجامعات من أهم المؤسسات المجتمعية التي تؤثر وتتأثر بالجو الاجتماعي المحيط بها، فهي من صنع المجتمع من ناحية، ومن ناحية أخرى هي أداته في صنع قياداته السياسية، الفكرية، الفنية، والمهنية، ومن هنا كان لكل جامعة رسالتها التي تتولى تحقيقها، فالجامعة في القرن العشرين تختلف رسالتها وغايتها عن الجامعة في القرن الحادي والعشرين. ولكي تقوم الجامعة بدور أفضل في خدمة المجتمع وتحمل المسؤولية المجتمعية فلابد لها من وض

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Publication Date
Wed May 11 2022
Journal Name
Journal Of The College Of Law/al-nahrain University
التزام الملاك بنفقات صيانة الاجزاء المشتركة وأعبائها في الاسكان العمودي.
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The phenomenon of multi-class construction and landlords has increased in Iraq, and this is not justified except because of the change in the economic and social conditions in it, because like any social system interacts with what happens in society, whether it is positive or negative, and since the vertical housing system contains common parts and these parts need to Maintenance and preservation, and in order to continue to perform the construction and other parts in an effective and regular manner for a long period of time and with appropriate efficiency, it must be maintained, and maintenance is one of the most important and difficult problems facing the partners. It is recognized that it is not possible to understand these practical dif

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Publication Date
Thu Jan 03 2019
Journal Name
Journal Of Planner And Development
دور قوانين الاستثمار في الانتاج السكني منطقة الدراسة- محافظة السليمانية
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Publication Date
Sat Dec 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
محاولة جادة لتأطير نظرية اصحاب المصالح في دراسات إدارة الاعمال
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المستخلص

تتميز هذه الورقة بتناولها موضوعاً يخشى الكثيرون الخوض فيه للملابسات الدائرة حوله، وهو اصحاب المصالح كموضوع مهم في الفكر الستراتيجي. فخاضت في مفاهيمه العامة وتصنيفاته ومنظوراته، ووجدت في مفهومه بأنهم اولئك الذين يمكن تمثيلهم بالمجاميع او الوحدات المستقلة التي ترتبط بمنظمة الاعمال عبر شبكة علاقات مؤثرة مختلفة الابعاد والاتجاهات، واذا ما حدث أي خلل في توازن هذه العلاقات، قد ت

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Publication Date
Sat Sep 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
استخدام برمجة (DeNovo) لتطوير شبكة المياه في استراتيجيات القرار المتعدد
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The object of this study is to establish a global model to use of DeNovo programming the strategies of multi-Decision making process in the city of Baghdad.

Thus, we have chosen an important and an effective subject in the life of the citizen due to the importance of this subject in the Iraqi citizen of luck of water and for many reasons.

In this thesis, we have tackled the establishment of a global model to be able to reach solution or an alternative model a money the available alternative.

        The alternative proposed here utilizes the application of the (DeNovo) programming approach suggested by (1982) in solving t

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Publication Date
Mon Dec 01 2025
Journal Name
مجلة الترجمة واللسانيات
الحبكة ودورها في الادب القصصي نماذج مختارة من الكتاب المقدس
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Publication Date
Fri Jan 11 2019
Journal Name
Iraqi Journal Of Physics
Porous silicon prepared by photo electrochemical etching assisted by laser
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Porous silicon (PS) layers are prepared by anodization for
different etching current densities. The samples are then
characterized the nanocrystalline porous silicon layer by X-Ray
Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier
Transform Infrared (FTIR). PS layers were formed on n-type Si
wafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2
current density for fixed 10 min etching times. XRD confirms the
formation of porous silicon, the crystal size is reduced toward
nanometric scale of the face centered cubic structure, and peak
becomes a broader with increasing the current density. The AFM
investigation shows the sponge like structure of PS at the lower
current density porous begi

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Publication Date
Fri Jun 30 2017
Journal Name
Journal Of Engineering
Aluminium Matrix Composites Fabricated by Friction Stir Processing A Review
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      Aluminum alloys widely use in production of the automobile and the aerospace because
they have low density, attractive mechanical properties with respect to their weight, better
corrosion and wear resistance, low thermal coefficient of expansion comparison with traditional
metals and alloys. Recently, researchers have shifted from single material to composite materials
to reduce weight and cost, improve quality, and high performance in structural materials.
Friction stir processing (FSP) has been successfully researched for manufacturing of metal
matrix composites (MMCs) and functional graded materials (FGMs), find out new possibilities
to chemically change the surfaces. It is shown th

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Publication Date
Thu Jan 02 2020
Journal Name
Arab Science Heritage Journal
الظاهرة اللغوية بين الوص ف والتفسير أث ر المفاهي م الكل ي ة في التوفيق بين الاتجاهين العقلاني والطبيعي في دراس ة اللغ ة البشرية
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This research investigates modern linguistics in terms of the “universality” concept, through which linguistics shifted its attention from the description of the phenomenon into finding an interpretation of it. Then it investigates what needs interpretation in the language

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