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.
Background: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u
... Show Moreالسياسة الروسية في الشرق الاوسط الكبير او (فن اقامة علاقات الصداقة مع كل دول العالم)
تعد ظاهرة الارهاب المتزايدة في العالم من اخطر اشكال التهديدات الامنية التي تواجة الدول لانها تستهدف في جانب مهم منها امن واستقرارومستقبل مجتمعاتها لاسيما اذا جمع الفعل الارهابي بين مطامع واهداف القوى الخارجية التي لا تريد استخدام ادواتها المباشرة وانما بالاعتماد على محركات في خلق الازمات داخل الدول المستهدفة
... Show MoreIrak Türk ağızları Azeri Türkçesinin bir uzantısı olarak değerlendirilir.Kerkük Türkçesiyle yazılan edebi ürünler, Irak Türkçesinin tamamını ifade etmek üzere kullanılmaktadır. Zamanın Eli divanı Kerkük Türkçesile yazılan bir eserdir. Bu yüzden bu divanı seçtik ve Irak Türkmen Türkçesi , Osmanlı Türkçesi ve Türkiye Türkçesi dilleri arasında karşılaştırmalı bir inceleme yaptık.
Bu araştırma, Irak Türkmen şairlerinden birisi sayılan Es’at Naib’in şiirleri üzerinde uygulamalı bir çalışmadanoluşmaktadır. Bu çalışmada adı geçen şairin “Zamanın Eli” Divanından bazışiirlerini önce yeni Türkçeye çevirdik vedaha sonra isim ç
... Show MoreI've dealt with my research is marked by ((urban and population planning for the city of Baghdad, during the reign of the Ottoman governor Muhammad Rashid Alkozlki 1852-1857)), a set of facts and incidents historical with the physical and demographic dimension, which passed on the history of the city of Baghdad on the fifth of the nineteenth century the contract during the Ottoman control Iraq, which lasted almost nearly four centuries
هدف البحث الحالي التعرف على فاعلية انموذج سكمب المعدل في الأصالة الرياضية واتجاه طلاب الصف السادس العلمي نحو البرهان الرياضي ، تَمَّ الاستعانة بالتصميم التجريبي ذي الاختبار البعدي والضبط الجزئي لمجوعتين متكافئتين (تجريبية وضابطة) ، تكونت عينة البحث من (55) طالباً من طلاب الصف السادس العلمي في ثانوية ابن الهيثم للبنين الواقعة في مركز محافظة القادسية ، جرى توزيع طلاب عينة البحث عشوائياً إلى مجموعتين إحداهما تج
... Show MoreIslamic Culture face many challenges Such as، Secularism، westrenism، globalism and Colonialism under current attempts For western States and united states of America to dominate on world and Confront all her Opponent Polaris it be clear when U. S. A. Occupied Afghanistan and Iraq and Threatened many Arabic and Islamic States
the history of Damascus by Ibn ' asaakir d. 571 a.h. 1272 m from local histories books concerned with male citizen narrators, to distinguish between rate and Rob them, this book is more a history of Islamic heritage books on Islamic City, and if we know that Ibn ' asaakir translated it for personal
In this work the effect of choosing tri-circular tube section had been addressed to minimize the end effector’s error, a comparison had been made between the tri-tube section and the traditional square cross section for a robot arm, the study shows that for the same weight of square section and tri-tube section the error may be reduced by about 33%.
A program had been built up by the use of MathCAD software to calculate the minimum weight of a square section robot arm that could with stand a given pay load and gives a minimum deflection. The second part of the program makes an optimization process for the dimension of the cross section and gives the dimensions of the tri-circular tube cross section that have the same weight of
... Show More