In this work, functionally graded materials were synthesized by centrifugal technique at different
volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T
= 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites
and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina
(Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength
occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value was
at 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the functionally
graded samples were enhanced by 43.69% and 52.74%, respectively, if loaded from the alumina-rich side.
On the other hand, when loading (FGM) from the epoxy side, the amount of decrease in bending resistance
was 122.4% while the improvement in bending modulus was 81.11% compared to pure epoxy. Scanning
electron microscopy (SEM) revealed the fracture surface of the impact samples and the gradient scattering of
nanoparticles in the epoxy matrix. Numerous applications can be used to manufacture the functionally
graded material by centrifugal casting method, including for the manufacture of gears and all bending
applications such as leaf springs.
ارتبط الانسان بالطبيعة بأشكالها المختلفة ارتباطا وثيقا ، فهي تمثل الحاضنة له بمجالات حياته كلها، فما كان من الأدباء الا أن يجعلوها في كثير من الأحيان مادة لأدبهم وأرضية خصبة لنتاجهم، فتمظهرت بصورها المختلفة وحاجة الانسان لها وخيرها وشرها في الأدب على مدى التاريخ، والعرب شأنهم شأن غيرهم من الأمم فمنذ عصر ما قبل الاسلام كانت الطبيعة منفذا مهما وملجأ للشعراء في انتاج الأدب وابداعه وإلى يومنا هذا، ونحن إذ نتحد
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העיון הזה מדבר על דבר ההשגה על הטקסטים המקראיים בידי כמה מסופרים ופילוסופים יהודים אשר הושפעו מהרעיונותיהם של הפילוסופים האירופיים מחד גיסא, ואת הרעיונות של ההשכלה מאידך גיסא. היהודים היו חיים בבידוד, ותחת השליטה של הרבנות (רבנים) שהייתה שליטה מוחלטת. כבר העבודה של הרבנות מאז ימי קדם להעלות רעיונות במוחם של היהודים בתור העם הנבחר, והם מעולים ועדיפים על בני אדם. הם כל כך מסתמכים על פסוקים מה
... Show Moreمشكلة البحث:- تواجه المجتمعات العربية في المرحلة الراهنة ,تحديات كبيرة تستهدف الشاب العربي ،والتأثير عليه في الجوانب الاجتماعية والتربوية والثقافية والاقتصادية والأمنية والسياسية ولغض تسليط الأضواء على هذه الجوانب ولاسيما الجانب الاجتماعي،من هنا تبرز مشكلة البحث الحالي في التعرف على توقعات الشباب العربي لمشكلاتهم الاجتماعية في المرحلة الراهنة .
أهمية البحث:-
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This research paper sheds light on the stages of Atmospheric forecast in Iraq. It was found that atmospheric forecast in Iraq has passed through several successive and interrelated historical stages. Each stage is characterized by special methods of prediction that are different from other stages. The oldest stages used astronomy to forecasting cases of cold , heat, flood and drought
يهدف هذا البحث الموسوم بـ (المنهج النقدي في كتاب الرجال للنجاشي(ت 450هـ )إلى تسليط الضوء على حياة النجاشي ومكانته العلمية والكشف عن منهجه النقدي في كتابه المذكور.
This study sheds light on female entrepreneurship in Palestine, and explores the reasons behind its relative weakness as compared with men, and with female entrepreneurship in other countries. This study aims at proposing effective policies and doable measures to enhance female entrepreneurship. Achieving this objective will carry significant impact on employment and economic growth at large, and increase women’s economic participation, scaling up their independence, and demonstrating their skills and abilities, and putting women on an equal footing with men. Furthermore, entrepreneurial activity has increasingly become one of the key drivers of economic development. An increased rate of entrepreneurial activities among women,
... Show MoreThere are many researches deals with constructing an efficient solutions for real problem having Multi - objective confronted with each others. In this paper we construct a decision for Multi – objectives based on building a mathematical model formulating a unique objective function by combining the confronted objectives functions. Also we are presented some theories concerning this problem. Areal application problem has been presented to show the efficiency of the performance of our model and the method. Finally we obtained some results by randomly generating some problems.
The current research aims to provide a conceptual and applied frame on the subject of multi- level analysis in the research of business administration. The research tries to address some of the problems that befall the preparation of research and studies at the Arab level and local level, where the unity of theory and measurement and analysis, as well as clarify the various types of conceptual constructs and give researchers the ability to distinguish different models related to the level of analysis. On the other hand, this research provides an example of
... Show MoreThis aim research of this discussion impact of investment in human capital dimensions (training, education, knowledge management, skills development) and its components (knowledge, skills, abilities, value) with the Office of the Inspector General's staff - Ministry of Culture in Iraq, has depended questionnaire as a tool in the collection data and information ,subjected to a measure of validity and reliability, and distributed to a sample of (63) individuals were distributed in positions (director, director of the Division of employees) have been analyzed data search using ready-statistical software (SPSS) the used hypothesis testing and correlati
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