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Study the Effect of Different Percentages of Natural (Orange Peels and Date Seeds) and Industrial Materials (Carbon and Silica) on the Mechanical and Thermal Properties of Polymeric Reinforced Composites
دراسة تاثير اضافة المواد الطبيعية (نوى التمر وقشور البرتقال) والصناعية (الكاربون والسليكا) على الخواص الميكانيكية والحرارية للمواد المركبة البولمرية

Authors: Haydar Abed Dahad حيدر عبد ضهد --- Sameh Fareed Hasan سامح فريد حسن --- Ali Hussein Alwan علي حسين علوان
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2018 Volume: 14 Issue: 4 Pages: 16-23
Publisher: Baghdad University جامعة بغداد

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Abstract

Mechanical and thermal properties of composites, consisted of unsaturated polyester resin, reinforced by different kinds of natural materials (Orange peels and Date seeds) and industrial materials (carbon and silica) with particle size 98 µm were studied. Various weight ratios, 5, 10, and 15 wt. % of natural and industrial materials have been infused into polyester. Tensile, three-point bending and thermal conductivity tests were conducted for the unfilled polyester, natural and industrial composite to identify the weight ratio effect on the properties of materials. The results indicated that when the weight ratio for polyester with date seeds increased from 10% to 15%, the maximum Young’s modulus decreased by 54%. When the weight ratio was 5%, the maximum Young’s modulus, yield stress and ultimate tensile stress occurred in the polyester with date seeds. The results of tensile and flexural tests showed that the natural composite material has a higher strength than the industrial material. While the results of flexural tests manifested that the maximum improvement in the flexural strength is obtained for orange peels at 5 wt. %, where the maximum increasing percentage is 153.4% than pure polyester. The thermal conductivity of orange peels decreased to the half value when the weight ratio increased from 10% to 15%. The thermal conductivity for polyester with orange peels was greater than the thermal conductivity of polyester with date seeds with maximum percentage occurred at weight ratio 10% is 14.4%, but the thermal conductivity of the industrial composite material was higher than the natural composite material. Finally, the date seeds composite was a good insulator and it had a reduced heat transfer rate in comparison to the rest of the samples, also the maximum variation of temperature with time occurred in date seeds composite.

تم دراسة الخصائص الميكانيكية والحرارية للمواد المركبة التي تتكون من بولي استر غير مشبع المقواة بأنواع مختلفة من المواد الطبيعية (قشر البرتقال ونوى التمر) والمواد الصناعية (الكربون والسيليكا) مع حجم حبيبي 98 ميكرون. تم اخذ قيم متلفة من النسب الوزنية، %5و %10و 15%. وقد تم اضافة مواد صناعية ومواد طبيعية الى البولي استر. وقد تم أجراء اختبارات الشد و الانحناء والتوصيل الحراري للبولي استر والمواد المركبة الطبيعية والصناعية لتحديد تأثير النسبة الوزنية على خصائص المواد. وأظهرت النتائج أنه عندما زادت نسبة الوزن للبوليستر مع نوى التمر من 10٪ إلى 15٪، انخفض معامل المرونة بنسبة 54٪. عندما تكون النسبة الوزنية لنوى التمر5٪ الحد الأقصى لمعامل المرونة والإجهاد الخضوع والإجهاد الكسر. وأظهرت نتائج اختبارات الشد واالانحناء أن المواد المركبة الطبيعية لها قوة أعلى من المادة الصناعية. في حين أظهرت نتائج اختبارات الانحناء أن الحد الأقصى من التحسن في قوة الانحناء يتم الحصول عليه لقشور البرتقال بنسبة 5٪ ، حيث الحد الأقصى لزيادة هي 153.4٪ بالمقارنة مع البوليستر النقي. وانخفضت الموصلية الحرارية من قشور البرتقال إلى قيمة النصف عندما زادت النسبة الوزنية من 10٪ إلى 15٪. الموصلية الحرارية للبوليستر مع قشور البرتقال أكبر من الموصلية الحرارية من البوليستر مع نوى التمر. وكانت النسبة المئوية القصوى عند النسبة الوزنية 10٪ هي 14.4٪ ولكن التوصيل الحراري للمواد المركبة الصناعية اعلى من المواد المركبة الطبيعية. وأخيرا، فإن المركب نوى التمر هو عازل جيد وله معدل نقل حراري منخفض بالمقارنة مع بقية العينات، وكذلك الاختلاف الأقصى لدرجات الحرارة مع مرور الوقت في مركب نوى التمر.


Article
Some Anatomical Changes in Placenta In Relation To Newborn`s Apgar score

Authors: Mohammed I. Ghanem --- Samia A. Eleiwe
Journal: Mustansiriya Medical Journal مجلة المستنصرية الطبية ISSN: 20701128 22274081 Year: 2014 Volume: 13 Issue: 1 Pages: 49-53
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Background: Sick newborns from apparently normal mothers, typically, have low Apgar scores and at such situation; there are great probabilities, for these newborns to develop several diseases, with poor outcomes. Also, there may be a chance for any prospect baby, to get same health state. Objective: This study was designed to correlate some of the placental topographic anatomical data with the newborn wellbeing, and to lay highlighting, on the presence of any placental abnormality, which could be caused by neither maternal nor fetal factors. Materials and methods: the study included 60 full term placentae of apparently normal mothers, who were admitted to Labor Room at al-Yarmook Teaching Hospital, al-Elwia Maternity Teaching Hospital and al- Khadhra`a Private Hospital, in Baghdad, for a normal vaginal delivery, or even for a caesarian section. The research was done over the period of 1stof February 2013 till end of 15thof April 2013. The newborns were scored high and low in Apgar score. The following anatomical data were selected in this study: the placental weight /newborn weight ratio, the mode of the umbilical cord insertion and the placental thickness, in each of the low and high Apgar score groups of fetuses, as indicators for the functional status of the placenta in these two groups. Results: The placental/newborn weight ratio in low Apgar score group of fetuses, was significantly lower than that in the high Apgar score ones. As regarding the umbilical cord mode of insertion; the eccentric type of insertion was more in both of fetal groups, nevertheless it was relatively higher in the high Apgar score group of fetuses, while the central type was more in the low Apgar score group of fetuses. The marginal type was only seen at the low Apgar score group of fetuses. The mean of thickness of placentae of low Apgar score group, was found to be less than that of the high Apgar score group, Conclusions: There was a strong and significant correlation between the fetal well being and data obtained from these topographic anatomical placental records.

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