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.
When we study the history of dentistry we can investigate some methodology styles which lead us to psychology – dentistry or take the relationship between psychology and dentistry, and this type of specialization which is Medical psychology has its own methodology and subjects, as the historical sequence in this filed lead to how evolution occurred in this branch of medicine, which was accompanied by many factors , and this factor that contributed to the consolidation of the misconceptions about the social, family and the media culture and gave a distorted picture of Dentistry and the attending physician or dentist and show him as someone tough , ruthless and violent in his dealings and style , these pro
... Show Moreهدفت الدراسة الحالية التعرف على البلادة العاطفية لطلبة الجامعة وكذلك التعرف على معنوية الفروق في البلادة العاطفية تبعاً لمتغيري: النوع (ذكور-اناث) والتخصص الدراسي (علمي –انساني) ، تآلفت عينة الدراسة من (400) طالب وطالبة موزعين بالتساوي حسب النوع والتخصص الدراسي تم اختيارهم عشوائيا من طلبة الجامعة، استخدمت الباحثة مقياس البلادة العاطفية من (اعداد الباحثة) وبعد تطبيق المقياس على عينة البحث واستخراج البيانات با
... Show Moreobjective of this research is to identify some of the obstacles that face secondary school teachers of the Arabic language courses in using modern teaching methods in class.
The research focuses on secondary school teachers of the Arabic language courses at the central region of Nineveh Governorate for the school year (2008-2009). 30 teachers out of 792, were randomly chosen to apply the research tool upon.
To fulfill the objective of this research, the researcher first surveyed a number of teachers , he then identified four categories of obstacles; obstacles related to school administrative system and environment, the teacher, courses and pupils, and the nature of teaching method
... Show MoreThe study aims to identify the concept of empowering women from the point of view of experts in the Palestinian society, specifically in Gaza, as well as to explore the foundations of their formation of this concept. Additionally, the study seeks to clarify the most important challenges facing the empowerment of women in Palestinian society. The study used the design of a grounded theory that seeks to build the theory through deep analysis of the data, as qualitative data were collected through holding two focus groups and six in-depth interviews with the study sample, who were selected by the method of targeted sampling. The sample included (16) individuals (9 female experts, 7 male experts) holding academic and community leadership pos
... Show MoreOur research, entitled(Population and economic determinants of society and its impact in the history of contemporary Baghdad 1940-1960), dealt with a number of historical facts and events of the social, demographic and economic
الملخص: لتحقيق أهداف البحث قامت الباحثتان ببناء مقياس للتفكك الاسري اعتمادا على نظرية (باندورا) وتكون بصورته النهائية من (24) فقرة ، وطبق المقياس على عينة البحث البالغة (150) تلميذ وتلميذة تم اختيارهم بالطريقة العشوائية البسيطة من مجتمع البحث ،وبعد جمع البيانات تم معالجتها باستعمال الوسائل الإحصائية منها الاختبار التائي، وتحليل التباين الرباعي والاختبار الفائي، وتوصل البحث الى النتائج الأتية :ان أفراد عينة ال
... Show Moreيُعدّ الأشخاص ذوو الإعاقة أكبر أقلية في العالم وأكثرها حرمانًا، حيث تشير الإحصاءات إلى أن نحو مليار شخص، أي ما يعادل 15% من سكان العالم، يعانون من بعض أشكال الإعاقة، مع تزايد معدلاتها في البلدان النامية. وتشير الدراسات العلمية إلى أن ذوي الإعاقة قادرون على مزاولة العمل بإتقان ومثابرة، بل وقد تتفوق مهاراتهم أحيانًا على مهارات الأشخاص غير المعاقين، إذا تم اختيار العمل المناسب لقدراتهم ومواهبهم. كما أن حق العمل
... Show Moreتعد دراسة التراث العلمي العربي من الدراسات التي تلقي الضوء على التطور التاريخي للعلوم العربية وما أنجزته العقلية العربية في هذا الميدان للمدة التاريخية التي ابتدأت بعصر صدر الإسلام وانتهت بالخلافة ويرى الكثير من العلماء سواء كان
The principal components analysis is used in analyzing many economic and social phenomena; and one of them is related to a large group in our society who are the university instructors. This phenomenon is the delay occurred in getting university instructor to his next scientific title. And as the determination of the principal components number inside the principal components depends on using many methods, we have compared between three of these methods that are: (BARTLETT, SCREE DIAGRAM, JOLLIFFE).
We concluded that JOLLIFFE method was the best one in analyzing the studying phenomenon data among these three methods, we found the most distinguishing factors effecting on t
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