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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
Thu Mar 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة الأساليب المستخدمة في تحديد عدد المركبات الرئيسية مع التطبيق العملي
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The principal components analysis is used in analyzing many economic and social phenomena; and one of them is related to a large group in our society who are the university instructors. This phenomenon is the delay occurred in getting university instructor to his next scientific title. And as the determination of the principal components number inside the principal components depends on using many methods, we have compared between three of these methods that are: (BARTLETT, SCREE DIAGRAM, JOLLIFFE).

     We concluded that JOLLIFFE method was the best one in analyzing the studying phenomenon data among these three methods, we found the most distinguishing factors effecting on t

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Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Measurement of some Air Pollutantsin Printing Units and Copy Centers Within Baghdad City
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Emissions of particulate matter from nanopapers as well as inks and organic solvents during the printing operationand copying machines constitute a threat to human health, especially with long time exposure in closed working environments. The present study was conducted in some printing houses and copying centers of Baghdad city during February and April  .The studyproved the occurrence of an air pollution problem concerning lead and zinc contents in all the study sites. The levels of Pb, Zn and Cu were collected by low volume sampler from the air of the study sites then filter papers digested and determined the heavy metals by flame atomic spectrophotometer. Particulate matter was measured by Aerocet, Microtector  meter device was use

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Publication Date
Tue Aug 01 2023
Journal Name
مجلة كلية دجلة الجامعة
تأثير التدقيق الداخلي على قيمة الوحدات الاقتصادية في ظل جائحة كورونا
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ت نايبتسلاا ثحابلا مدختسا دقو ,ةيداصتقلاا تادحولا ةميق ىلع انوروك ةحئاج لظ يف يلخادلا قيقدتلا ريثأت ةيداصتقلاا تادحولا فادها قيقحت يف مهسي يلخادلا قيقدتلا نا ثحبلا تاجاتنتسا مها تناكو , ثحبلا تاريغتم نيب ةقلاعلا نايبل رطاخملا ةرادأو اهتءافكو اهتيلعاف نيسحتو قيقدتلا عقوم زيزعت ىلع لمعلا تايصوتلا مها تناكو امك, ةمكوحلا تايلمعو ةباقرلاو قيقحتل رارمتسأب ئراوطلا ططخ ثيدحتو ةبقارمو ةحضاو تازفحم ءاشناو ةلمتحم

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Publication Date
Fri May 01 2020
Journal Name
مجلة بحوث الشرق الأوسط
دراسة مقارنة لمستوى التمکین الإداری بین مشرفی التربیة الریاضیة (الاختصاص والفنی) لمدیریات التربیة فی محافظة بغداد A Comparative Study of the Level of Administrative Empowerment between the Physical Education Supervisors (Specialization and Technical) of Education Directorate in Baghdad Governorate
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Publication Date
Mon Jul 14 2025
Journal Name
Al-fatih Journal
Development of explosive power training with weights in a way the ups and downs and its impact on the improvement of some variables Albyukinmetekih and technical performance of the skill of a leap forward on your hands vaulting modern
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Publication Date
Mon Jan 23 2023
Journal Name
Arab Science Heritage Journal
رحلة الحاج الموريسكي بوي مونثون من إسبانيا إلى مكة المكرمة بعد تسليم مملكة غرناطة 897هـ - 1492م، دراسة في مضامين الرحلة "نماذج مختارة" دراسة في مضامين الرّحلة "نماذج مختارة"
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Day after day, Morsek literature 879-1018/1492-1609proves the completion of all literary branches starting from poetry with its different purposes to include prose with its various subjects. In 2016, a complete text of ‘the literature of Morsek journeys

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Publication Date
Mon Dec 26 2022
Journal Name
Arab Science Heritage Journal
رحلة الحاج الموريسكي بوي مونثون من إسبانيا إلى مكة المكرمة بعد تسليم مملكة غرناطة 897هـ - 1492م، دراسة في مضامين الرحلة "نماذج مختارة" دراسة في مضامين الرّحلة "نماذج مختارة"
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Day after day, Morsek literature 879-1018/1492-1609proves the completion of all literary branches starting from poetry with its different purposes to include prose with its various subjects. In 2016, a complete text of ‘the literature of Morsek journey

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Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
اثر استخدام انموذج سكمان في تحصیل طالبات الصف الثاني متوسط ومیلھن نحو مادة الفیزیاء: اثر استخدام انموذج سكمان في تحصیل طالبات الصف الثاني متوسط ومیلھن نحو مادة الفیزیاء
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Publication Date
Sun Jul 23 2017
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
UTILIZATION OF MODIFIED ATMOSPHERE PACKAGING TO EXTEND SHELF LIFE AND MAINTAIN QUALITY OF KHALAL BARHI DATES: UTILIZATION OF MODIFIED ATMOSPHERE PACKAGING TO EXTEND SHELF LIFE AND MAINTAIN QUALITY OF KHALAL BARHI DATES
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Barhi dates fruit are one of the most important date palm cultivars which are some of their properties they are mostly eaten and sold at the khalal stage when it has become yellow compared with rutab stage. At this stage the fruit loses its astringency and becomes sweet and best texture, therefore. High moisture content and rapid ripening of Barhi dates shorten their shelf life, as well the Khalal stage lasts for about 4 weeks until the ripening of the fruits begins and transfer to rutab stage. In the present study, Barhi dates packaging in the first by common air - packaging and
second by Modified atmosphere packaging, MAP A (5% O2 + 20% CO2) and MAP B (40%O2+20%CO2) and stored for 30 days at different temperatures 5 and 20 °C, re

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Publication Date
Wed Nov 22 2017
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
THE EFFECT OF FERMENTATION AND BAKING PROCESSES ON THE PHYATE DEGRADATION DURING THE PROCESS OF MANUFACTURING WHOLE WHEAT FLOUR BREAD.: THE EFFECT OF FERMENTATION AND BAKING PROCESSES ON THE PHYATE DEGRADATION DURING THE PROCESS OF MANUFACTURING WHOLE WHEAT FLOUR BREAD.
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In this research, the influence of the fermentation treatments and baking in Iraqi’s flour type (Ibaa 99, Al-rashed, Tamus, Abu-grabe) and Turkish flour type (Muaamel) on phytic acid was investigated. In whole wheat flour, the phytic acid was (1500, 1290, 1450, 1230, 1440 ( mg/ 100 g flour respectively, and the inorganic phosphorous was (29.18, 25.15, 23.89, 20.85, 22.83) mg/100 g flour respectively. The dough prepared from flour with a higher phytic acid content also contained higher amount of phytic acid. During fermentation, degradation of phytic acid occurred. The cumulative loss of phytic acid after fermentation in all type of dough was ~ 23, 22, 34, 26 and 27% respectively،While increased of inorganic phosphorous occurred. The c

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