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alkej-389
Transient Behavior Analysis for Solar Energy Storage in PCM-CFM Material Using Equivalent Heat Capacity Method as Storage Model
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A paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30o, 45o and 60o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat method was employed to describe the heat storage and release in the mushy zone. Experimental results referred to an increase in thermal conductivity of paraffin wax that supported by copper foam matrix more than ten times. While the ventilation effect was still active for hours after the sun set, depending on the heat storage amount. Maximum ventilation mass flow rate with TESB collector was recorded with value equals to 36.651 kg/hr., when the overall discharge coefficient that was calculated for the system equals to 0.371. Experimental results showed that the best working angle range was 45~60o, and the highest air to the collector approaching temperature appeared to the double passes flat plate collector. Results gave greater heat storage efficiency of (47)% when the maximum solar radiation was 780 W/m2 at 12.00pm, while the energy summation through duration charge time was 18460 kJ. Computational results, depending on the equivalent heat capacity method for heat storage or release from phase change material that supported by copper foam matrix, showed the behavior of paraffin wax melting and solidification situation through periodic for charge and released heat from the solar collector. Also, these results gave agreement approaching the experimental results for the heat storage in the combined heat storage material, with standard error of 16.8%.

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Publication Date
Fri Dec 31 2021
Journal Name
Iraqi Journal Of Laser
The influence of no-core fibre length on the sensitivity Optical fibre Humidity sensor
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Abstract: Reflection optical fibre Humidity sensor is presented in this work, which is based on no core fibre prepared by splicing a segment of no core fibre (NCF) at different lengths 1-6 cm with fixed diameter 125 µm and a single mode fibre (SMF). The range of humidity inside the chamber is controlled from 30% to 90% RH at temperature ~ 30 °С. The experimental result shows that the resonant wavelength dip shift decreases linearly with an increment of RH% and the sensitivity of the sensor increased linearly with an increasing in the length of NCF. However, a high sensitivity 716.07pm/RH% is obtained at length 5cm with good stability and reputability.  Furthermore, the sensor is shif

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Publication Date
Wed Nov 14 2018
Journal Name
Arab Science Heritage Journal
المنهج المنهج الأدبي في كتاب "أدب الكتاب" للصولي (ت335هـ) دراسة منهجية
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It is summarized that Abu-Baker Al-Soly is one of Arabic Muslim scientists who had special style in literary writing specifically in sciences and knowledge that had depended on the encyclopedia culture gained from various fields of science , this means that he was an individual who had participated to characterize features of Islamic –Arabic history enhanced the rules of it , this matter would encourage us to know the method and style of writing in the field of intellectual life in which the writer depended on the procedures direction of scientists that he lived in the Abbasid era .

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Publication Date
Fri Jun 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
جدلية التنظرية في الذاكرة المنظمة بين متاهة النماذج الصناعية وواقعيةالنموذج الهجين
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جدلية التنظرية في الذاكرة المنظمة بين متاهة النماذج الصناعية وواقعيةالنموذج الهجين

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Publication Date
Wed Dec 12 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Stress and Its Associated Factors among Students of the College of Nursing University of Baghdad
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Objectives: The current study aims at identifying the level of perceived stress among nursing college students and determining the factors associated with stress they have. Methodology: A cross-sectional descriptive study initiated for the period on November 1st, 2014 to May 1st, 2015. The study has been conducted on the undergraduate nursing college students / University of Baghdad. The sample of the study was consisted of (128) students who were selected purposively. The questionnaire of the study was adopted and modified for the present study which consisted of socio-demographic data and the scale of

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
أثر تحسين جودة الخدمات التأمينية في تحقيق المزايا التنافسية: دراسة ميدانيــة
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يعد التأمين أحد المؤسسات المالية ذات التأثير على برامج التنمية ، وما زال قطاع التأمين يعاني من العديد من المشاكل منها الوعي أو التشريع أو كيفية توظيفه كمورد اقتصادي واجتماعي خدمة للمجتمع والمؤسسات والافراد. وحيث أن التأمين يقدم خدمة تستوجب التزامها بمواصفات محددة ، لذا أصبح من الضروري دراسة آليات تحسين جودة الخدمة التأمينية وكذلك دراسة واقع العملية التسويقية للخدمة التأمينية وما ينالها من تحديات داخلية أ

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Publication Date
Tue Jul 02 2024
Journal Name
مجلة الأستاذ للعلوم الإنسانية والإجتماعية
بنية الزمن في رواية ( ما بعد الجحيم ) للدكتور حسين سرمك حسن .
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يعد الزمان عنصراً جمالياً مساهماً له القدرة على خلق المعنى والدلالة ، ومشاركاً في الاستراتيجية الحكائية إذ ينتقل من مجرد عنصر حكائي إلى محرض للمتلقي فهو زمان الإنسان الداخلي .

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Publication Date
Wed Jul 01 2015
Journal Name
Journal Of Educational And Psychological Researches
مدخل في سيكولوجيــة طب الاسنــان علم نفس طب الاسنــان (Psychology Dentistry )
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When we study the history of dentistry we can investigate some methodology styles which  lead us to psychology – dentistry or take the relationship between psychology and dentistry, and this type of specialization  which is Medical psychology has its own methodology and subjects, as the historical sequence in this filed lead to how evolution occurred in this branch of medicine, which was accompanied by many factors , and this factor that contributed to the consolidation of the misconceptions about the social, family and the media culture and gave a distorted picture of Dentistry and the attending physician or dentist  and show  him as someone tough , ruthless and violent in his dealings and style , these pro

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Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
Personal and Moral Responsibility and Its Relation with Moral Flexibility upon Faculty of Secondary Schools
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Abstract

The factor that keeps society from collapsing and regressing to chaos, violence, and lawbreaking is to stick to the human moral principles and criteria of moral behavior that prevent the spread of corruption and crime to the extent that law becomes devoid of activity and loss its dot errant power in front of chaos. The role of moral behavior is to motivate individuals to respect the general laws in dealing with others. Because of the dissemination of odd behavior patterns within our society, the social links are been badly affected and it's urgent for educational institutions to perform their duty in working on spreading awareness about moral values and avoid deviant directions and socially threatening t

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Publication Date
Thu Jul 01 2010
Journal Name
Political Sciences Journal
السياسة الداخلية لعراق ما بعد الانتخابات 2010 دراسة في الثوابت والمتغيرات
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السياسة الداخلية لعراق ما بعد الانتخابات 2010 دراسة في الثوابت والمتغيرات

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Publication Date
Sat Sep 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Director's leadership features and Impact on productive efficiency Study at Iraqi general insurance company: Study at Iraqi general insurance company
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أدى التغير السريع في البيئة الخارجية للمنظمة إلى  ظهور حالة من التنافس الشديد مما زاد تخوف الشركات من فقدان الحصة السوقية والخسارة . مما حدا بالمنظمات إلى الاهتمام بوجود مدير يحمل صفات وخصائص قيادية لما فيه من ميزات في تنظيم الإنتاج  ومقابلة الطلب وتقليل التكاليف وتطوير الأداء للحصول على ميزة تنافسية تحافظ او تزيد من حصتها السوقية وإرباحها .

تسعى الدراسة الى تحديد عدد من الاهداف كان اهمها معرفة الع

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