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.
من اهداف بعض التجارب هي معرفة تاثير التسلسلات المختلفة لبعض الادوية او التغذية او تجارب التعلم. وفي بعض الاحيان قد تكون الوحدات التجريبية نادرة لهذا نقوم باستخدام الوحدات التجريبية على نحو متكرر. او بسبب الميزانية المحدودة فان صاحب التجربة يخضع كل وحدة تجريبية لاختبارات عديدة ويطلق على هذا النوع من التجارب التي يتم فيها استخدام الوحدات التجريبية (الاشخاص) Subject على نحو متكرر
... Show MoreThe Negro minority in the United States is associated with social injustice,
political deprivation, and economic oppresion. Its members felt that they are
second-class citizens, and that the acceptance of such status will lead to the
continual oppresion of the Whites upon them. As a result, the educated community
adopted a process to put a framework to their opposition to the former's injustice.
This organised framework is exemplified in the "Niagara Movement," which is
regarded as the first national organisation for Negros. The topic of this study is
chosen due to its historical and political significance.
The study consists of an introduction and five sections. The first section
addresses the preliminaries an
This study attempts to highlights on the evaluation of performance efficiency for Investments in both National & Iraqi Insurance companies for the years 2001-2010 and their importance on those companies and the economy of the country in order to find out the investment areas and to compare between investment activity and its revenues as well as to compare performance of both companies in investment field.
The study was based on annual reports and balance sheets of both companies. In many chapters, this study dealt with theoretical and practical aspects of the investments and its revenues. Key hypothesis was based on this study, including four parts of Sub hypotheses about (statistical effective relationship between the
... Show MoreThe problem of the present study lies in the challenges that college education especially that concerns the quality of college teachers performance and developing the level of educational process quality.
This study aimed at constructing a vision the researchers have constructed depending on the standards of performance quality represented by Deming's quality course. The researchers presented a number of skills that should be existed in the performance of college teacher through using the analytic and constructing approach in imagining this drawing to develop performance.
The study results represented by a number of efficiencies that college teachers shoul
... Show Moreيعد شعر المنفى احد اهم روافد الادب المعاصر فهو يعكس الإبداع الشعري الحقيقي للشاعر المنفي، ويعكس في الوقت ذاته الحنين والألم الذي يعاني منه بسبب البعد عن وطنه. ومن ناحية أخرى، يصور شعر المنفى حالة المقاومة والنضال التي يختزنها الشاعر . نتناول في هذا البحث م وضوع شعر المنفى عند شاعرين منفيين لم يلتقيا في بلد واحد ولم يتبنيا ثقافة فكرية مشتركة, إلا أن الشاعرين تحملا نفس مرارة المنفى التي عبرا عنها بشكل واضح في شعر
... Show MoreFind aimed to reveal the teaching practices of the teaching faculties of education departments of the University of Baghdad in the light of the motives of learning from the perspective of students . Researcher selected the research community in a deliberate humanitarian sections of students and faculties of education for girls and IbnRushd . Ed reached basic research sample ( 400 ) students were numbers search tool questionnaire , and included (30) paragraph . In processors statistical data , use the weighted average and the weight percentile , results have shown that it is more paragraphs which received wide acceptance from the viewpoint of students ( do not make fun of the students' answers wrong but corrects and discussed with them )
... Show Moreولد ابو بكر محمد بن زكريا الرازي في الري سنة 250هـ (864م) وتعمق في الطب والكيمياء والفلك والأدب والفلسفة وهو أحد مشاهير الاطباء في زمانه وهذا هو السبب الذي دعاه لأن يتنقل من بلاط الى اَخر , ولم ينعم بالأستقرار في حياته بالنظر الى تقلب الأهواء والاُمراء وأضطراب الأحوال السياسية . قام برحلات كثيرة , وعهدت اليه ادارة بيمارستان ( مصح ومشفى ) الري ثم قام بهذه المهمة نفسها في بغداد.
لقب بـ( طبي
... Show Moreعملية صناعة واتخاذ القرار في السياسة الخارجية للرئيس جورج والكر بوش
وقائع واوراق ندوة (السياسة الخارجية الامريكية في عهد اوباما) التي عقدها فرع الدراسات الدولية في 25 تشرين الثاني 2009