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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
Mon Apr 29 2019
Journal Name
Arab Science Heritage Journal
التطور التطــــــور التـــاريخي للمحكـــمة الاتحادية العـــليا في العــراق وفــق التشـــريعــات القــانــونية الــتي تم اصــــدارهــــا
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On the research that is marked by the historical development of the Supreme Federal Court in Iraq accordance with the issued legal legislations Research Submitted by Adel Amran Hamad Faculty Member, the college of Biotechnology

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Publication Date
Mon Oct 06 2014
Journal Name
Journal Of Educational And Psychological Researches
اثر برنامج أنشطة مكتبية لتنمية بعض القدرات الإبداعية في الأداء اللغوي عند اطفال الرياض
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This study aims to find out the impact of activities office provided to kindergarten children in the development of creativity in linguistic performance goal of capabilities (fluency, flexibility and originality) through the application of the test configuration Algheih Children Riyadh, which consists of (70) Single to measure the skills of language arts four a listening and speaking and a willingness to read and prepare for writing, was applied (30) Single of language arts, listening and speaking in this research, and was the correlation coefficient for the hearing (0.78) and for speaking was (0.61) has been extracted stability of the scale using the equation Alvakronbach the value of (0.73).

The proper

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Publication Date
Sun Jul 03 2005
Journal Name
Political Sciences Journal
التوجهات الفكرية الجديدة لانظمة دول العالم الثالث في ظل النظام العالمي الجديد : العراق نموذجاً
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التوجهات الفكرية الجديدة لانظمة دول العالم الثالث في ظل النظام العالمي الجديد : العراق نموذجاً

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Publication Date
Sun Jan 01 2017
Journal Name
Journal Of The College Of Languages (jcl)
Traducción de los dos verbos auxiliares ser y estar del español al árabe en la frase nominal
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Resumen:

       La traducción de los dos verbos ser y estar no es una tarea tan simple como piensan muchas personas, sino es una de las complicadas y difíciles tareas, ya que el traductor tiene que saber y perfeccionar los correctos casos gramaticales relacionados con esos dos verbos auxiliares  tanto el verbo ser como el verbo estar, especialmente en la frase nominal para que pueda dar una clara y correcta traducción. Usados con el mismo adjetivo, "ser" comunicará una cualidad que es parte de la identidad o naturaleza del sujeto, mientras que "estar" comunicará un estado o circunstancia del mismo. Este e

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Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
Vocabulary Learning Strategies Employed by English as Foreign Language Students at NBU University
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ABSTRACT

Learning vocabulary is a challenging task for female English as a foreign language (EFL) students. Thus, improving students’ knowledge of vocabulary is critical if they are to make progress in learning a new language. The current study aimed at exploring the vocabulary learning strategies used by EFL students at Northern Border University (NBU). It also aimed to identify the mechanisms applied by EFL students at NBU University to learn vocabulary. It also aimed at evaluating the approaches adopted by EFL female students at Northern Border University (NBU) to learn a language. The study adopted the descriptive-analytical method. Two research instruments were developed to collect data namely, a survey qu

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Publication Date
Sun Apr 03 2011
Journal Name
Journal Of Educational And Psychological Researches
أثر التدريس بطريقة التنقيب الحواري في حفظ النصوص الأدبية لدى طلبة قسم اللغة الكردية
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يهدف البحث الحالي إلى معرفة اثر التدريس بطريقة التنقيب الحواري في حفظ النصوص الأدبية لدى طلبة قسم اللغة الكردية، اختارت الباحثة طلبة المرحلة الثانية في قسم اللغة الكردية بكلية التربية ابن رشد، للعام الدراسي
(2008-2009) ميدان لتطبيق تجربتها.
تألفت عينة الدراسة من (48) طالبا وطالبة، تم توزيعها عشوائيا إلى مجموعتين، مجموعة ضابطة (درست بالطريقة الاعتيادية) تألفت من (23) طالبا وطالبة ومجموعة تجريبية (درست بطريقة الت

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Publication Date
Wed Oct 01 2008
Journal Name
Journal Of Educational And Psychological Researches
الضغوط النفسية والعوامل الاجتماعية المؤدية إلى الإصابة بأمراض القولون ( بحث ميداني في مدينة بغداد )
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بالنظر الظروف الراهنة التي يمر بها قطرنا ونتيجة للارتفاع معدل الاصابة بالامراض ذات الطابع النفسي جسمي او ما تعرف بامراض سوء التكيف الناتج عن الضغوط النفسية المستمرة.

ارتأت الحاجة الى دراسة هذا النوع من المرض والتي ترجعها الباحثة الى الاسباب التالية :.

1-تعرض المواطن العراقي الى ضغوط نفسية مستمرة متمثلة بحالة الانفلات الامني والشعور بالقلق المستمر المراف

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Publication Date
Sun Jun 12 2011
Journal Name
Baghdad Science Journal
Parabolic Trough Solar Collector – Design, Construction and Testing
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This paper presents the design, construction and investigates an experimental study of a parabolic Trough Solar Collector (PTSC). It is constructed of multi – piece glass mirror to form the parabolic reflector (1.8 m ? 2.8 m) its form were checked with help of a laser and carbon steel rectangular as receiver. Sun tracker has been developed (using two – axis) to track solar PTSC according to the direction of beam propagation of solar radiation. Using synthetic oil as a heat transfer its capability to heat transfer and load high temperature (?400 oc). The storage tank is fabricated with stainless steel of size 50 L. The experimental tests have been carried out in Baghdad climatic conditions (33.3o N, 44.4o E) during selective days of the

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Intelligent Systems
Void-hole aware and reliable data forwarding strategy for underwater wireless sensor networks
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Abstract<p>Reliable data transfer and energy efficiency are the essential considerations for network performance in resource-constrained underwater environments. One of the efficient approaches for data routing in underwater wireless sensor networks (UWSNs) is clustering, in which the data packets are transferred from sensor nodes to the cluster head (CH). Data packets are then forwarded to a sink node in a single or multiple hops manners, which can possibly increase energy depletion of the CH as compared to other nodes. While several mechanisms have been proposed for cluster formation and CH selection to ensure efficient delivery of data packets, less attention has been given to massive data co</p> ... Show More
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Crossref (5)
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Publication Date
Wed Jun 30 2010
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Producing Oil from Dead Oil Wells Using injected LPG
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In order to reduce hydrostatic pressure in oil wells and produce oil from dead oil wells, laboratory rig was constructed, by injecting LPG through pipe containing mixture of two to one part of East Baghdad crude oil and water. The used pressure of injection was 2.0 bar, which results the hydrostatic pressure reduction around 246 to 222 mbar and flow rate of 34.5 liter/hr fluid (oil-water), at 220 cm injection depth. Effects of other operating parameters were also studied on the behavior of two phase flow and on the production of oil from dead oil wells.

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