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.
الفيدرالية : نظرة في منطلقاتها الفكرية وآفاقها المستقبلية
تعـد الوحـدة الوطنيـة لأي شـعب قاعـدة الارتكـاز للبنـاء الحضـاري والتقـدم والتطـور والتنميـة في المجـالات كافـة وبغيابها يفقد الشعب المرتكزات الأساسية لآمنه واستقراره، وقدرته على احتواء الأزمات الناشئة عن الاختلافات العرقيـة والدينية والطائفية، وعلى هذا الأساس فان قيادات الشعب الوطنية يكون هاجسها الدائم الحفاظ على الوحدة الوطنية، وسـد كـل الثغـرات والمنافـذ في جـدرانها لكـي لاتنفـذ مـن خلالهـا ريـاح
... Show MoreAcademic libraries characterized from other libraries in the groups of literacy acquired, and
ways to retrieve this information, where it is supposed supply of various combinations of traditional
sources, electronic information, such as books and references, maps and indexes, CD-ROMs and
service-line and so on, via electronic mediator or via the Internet instead of the mediator paper. The
digital technology has changed the way you work by academic libraries, where confined to the
primary mission of these libraries to provide prompt services to the needs of researchers, professors
and students, and the provision of reading different materials, including electronic sources that
support the curriculum and research in el
دور المنظمات الدولية في تفسير معاهداتها المنشئة
in his Diwan, and standing on them, and determines This study dealt with the lexical and semantic fields in the sentimental poems in Walid Hussein's Diwan (I do not desire to whisper the question) that the classification
Quran is a basic reference of production it is as a source to all sciences, Ayat of Quran would mention the importance of benefits of animals. Quran contain full surrat named in animal names as Al-Baqara that is to clarify its benefits and importance in human’s life.
يهدف البحث الى استخدام بحوث العمليات في اتخاذ القرارات الادارية لما لها من اهمية في مواكبة التطورات الحاصلة في مجال استراتيجيات الاعمال ونظم المعلوماتية وإدارة المعرفة في القرن الحالي، إذ لم تعد الأساليب التقليدية في اتخاذ القرارات الإدارية مجدية بعد ظهور توجهات حديثة في الإدارة تركز على ضرورة الاعتماد على الأساليب الكمية كبحوث العمليات, وقد تطور استخدام بحوث العمليات في السنوات الماضية بشكل كبير وأصبحت أ
... Show MoreIn this research the subject of human ability to change, as it is proven in the Koran , which is proof of the argument against the ability of human change , whether the change in the positive or negative direction .
Here the limits of the research are limited to a study of analysis of human ability to change and this establishes the important of knowing that man has the ability while in the wrong way to change the path to the right path which Gifts and guidance .
The search required three demands and conclusion
- The first required :- is to try the idolaters to take out believers by right .
- The second required :- is to change what is inside the soul as a reason to enter blessings on man .
- The third required :- is good
The God Almighty prefer on the Arab nation, and entrusted to carry his message to the secular world as a whole, , gave her all necessities of life in terms of location, who are the heart in the earth's surface. From this blessed place emerged the greatest civilizations and the world has ever known for it than in human history, a four empires Alsamyat