In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at these parameters and comparing them with the randomly used once. The experimental and analytical results showed that the Taguchi method was successful in optimizing the parameters that give the highest properties and it can find the most influential parameter regardless of the material used. Also it showed that the volume fraction was the most influential parameter on the tensile and impact strength. The difference between these composites was in the properties values and that the Kevlar composites have higher tensile and impact strength.
تواجه المؤسسات المختلفة تحديات كثيره تختلف نوعيتها باختلاف توجهات المؤسسه سياسيه او اقتصادية او اجتماعيه ... مما يشكل تهديدا لوجود المؤسسة وسمعتها وبخاصه عند تحول تلك التحديات الى ازمات يجب على المؤسسه التعامل معها والسيطره عليها واحتوائها وهنا ياتي دور ادارة العلاقات العامه في المؤسسه المعنيه للعمل والقيام باعداد برامج خاصه بالتعامل مع الازمات وهو مايعرف ببرامج اداره الازمات . وبطبيعة الحال تختلف عملية
... Show MoreWater resources would be differentiate in Morocco specially in Morocco which appear as form of eyes ,rivers as dissolved water of mountain.
The human takes care of water either as rains to store and use in necessity trying to bring it to Maracas by helping from state .
The religious tried to dig wells to emphasize that water is rumored and do not monopolized.
بحثنا الموسوم بـ (الأغلاط اللغوية في كتاب الإنسان الثاني لمحمود عباس العقاد دراسة في ضوء كتب التصحيح اللغوي الحديثة)، ليس الغاية منه النيل من شخص كاتب كبير، وعلم من أعلام الأدب العربي، بل اعتماد الموضوعية والرد على القول الشائع: (الخطأ الشائع خير من الصواب الضائع)، إذ إِن كثيرًا ممن يسلكون درب الأغلاط اللغوية يعمدون الى التمسك بها محتجين بأن ما ورد في تعبيراتهم ورد في تعبيرات كتّاب كبار، فضلاً عن أن الباحثة ل
... Show Moreيهدف البحث الى دراسة وتحليل التمويل الأخضر كأحد المفاهيم الاساسية والحديثة في عالم الاعمال والاقتصاد العالمي وخاصة بعد الازمات والتحديات التي توالت على العالم نتيجة الكوارث الطبيعة وتغييرات المناخ والضغوطات على الموارد الطبيعية والتي أدت الى احداث اثرا كبيرا في اقتصاديات الكثير من الدول ، مما اضطرت الى إعادة النظر في مشاريعها وانشطتها الاستثمارية بما يوائم وطبيعة البيئة ومتغيراتها ، لذا تحتم اختيار لمثل
... Show MoreThe purpose of this research is to suggest a model which may be used by law enforcement to broaden individual and organizational creativity while providing a more inclusive, holistic view of management within our internal and external organizational structures. This project introduces alternatives to traditional management, leadership styles and problem solving strategies. Law enforcement organizations in the 21st century will face many challenges. Much like community policing impacted the nation in the mid 1980's through the 1990's, the systems thinking approach offers a philosophy for the new millennium.
Most organizations will face many challenges in the next decade of the twentieth first century. Just
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Abstract
The health section is considered to be one of the most important section in the field of service economical and social unit because of its concern in the life of human begin and society and the process of determining t
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The research deals with the Presidents of the Christians who called themselves (Ghaltka) in the book titled (orient chirsy patriarchs) that talked about their scientific practical biography adding to) that their completeness on the position of Ghaltka with its decrees and caliphs who were contemporaries to them ,as well as their places, deaths, cemeteries and their accomplishments In accordance with the powers granted to them and also it mentions the situation of The Abbasid caliphate with them and with the sons of their sect .
يهدف البحث إلى تحضير سلسلة جديدة من معقدات العناصر الانتقالية ثنائية التكافؤ (الكوبلت, النيكل, النحاس, الخارصين ,الكادميوم والزئبق) مع المركبات الحلقية غير المتجانسة (L1) و(L2) والمشتقة من تفاعل 2,1- فينيلين ثنائي امين وسايكلوهكسان -2,1-ثنائي امين مع المركب الوسطي (Pr) على التوالي. شخصت المعقدات ذات الصيغة العامة :- [M(L1or L2)Cl2] بواسطة طيف الرنين النووي المغناطيسي البروتوني والكربوني وقيا
... Show MoreThe writer of this messagewas Tajaddin Ahmad Abdulqader bin Maktoom Al-Qaisy Al-masry.
This message dealt with the biographies of twenty scientists of readers about Quran readings in Cairo . He comprehended these biographies and make it an appendage
he is one of the most prominent Arab personalities who contributed in the Arab Muslim world, scholars and historians who appeared in the seventh century AH - the thirteenth century AD, contributed to enrich the Arab scientific heritage in his distinguished book “The Wonders of Creatures and the Strangeness of Existences” because it contained what God Almighty created and the oddities on dry land and water