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.
إن التطور الهائل في منظومة تكنولوجيا المعلومات والاتصالات في العالم , أثر كثيراً في الجوانب الحياتية والاجتماعية والاقتصادية والسياسية والثقافية عامة والتربوية والتعليمية خاصة, إذ أصبح لها دور كبير في تسيير الكثير من الأمور. ولا بد من القول ان المؤسسات والمنظمات لا يمكن ان تنتقل من القرن العشرين الى القرن الحادي والعشرين إلا إذا أفادت من تكنولوجيا المعلومات والاتصالات, إذ توافر هذه التكنولوجيا الكثير من ال
... Show MoreBank credit function plays an important role in realizing the targets of commercial banks , so that the credit dominate the most of assets for these banks , also the credit contribute by bigger share of operational income for these banks .Bank credit faces
high challenge that it is bank credit risks which hinder realizing goals of bank credit . the researcher discover that in spite of the international accounting standards assured that it is necessary to disclose about risks related assets, which include bank credit, and also disclosure about fund which specified to face probable loss for this credit , but the recent disclosure about bank credit risks and its provision indicate that it faces sever defect which hinder
... Show MoreThe Stressful Life Events consider one of the important thing in humans life in different period of life even school period, where it is deal with vital period of life which is the youth period that represent the hope and precious resources that nation depend on it in building her civilization, structure anddevelopment ,they are part from the present and whole future .As the great effect of stressful life event on humans , increase the need to put a program about psyching-up which consider one of the modren and effective programs.The aim of current search:1. Measure the level of stressful events at the junior high school studen
... Show MoreTo evaluate the toxicity of benzalkonium chloride in aquaculture, the hemato-serological indices of Nile tilapia Oreochromis niloticus are used as biomarkers. Following exposure to three concentrations of benzalkonium chloride BAC 0.1, 0.25, 0.50, and 1 mg/l (BAC1,2,3 and 4) in aquaria for two durations 21 and 42 days, the microbiological assay in fish aquaria, in addition to blood parameters were assessed. Except for the mean difference between BAC2 and BAC3 (P > 0.05) at 42 days, the mean values of the bacterial counts revealed a significant difference between all compared groups (0.05 ≥ P ≤ 0.01). Following exposure to the lower concentrations of BAC (1, 2 and 3), the main blood parameters of Oreochromis niloticus namely red bl
... Show Moreان دراسة الاحوال الاجتماعية في الاسكندرية خلال العصر المملوكي امر مهم لاسيما ان الحياة الاجتماعية في مصر عامة والاسكندرية خاصة اتصفت بكونها بطيئة التغيير خلاف جوانب الحياة الاخرى التي اتصفت بسرعة تغير مجراها كما وان تاريخ الاسكندرية الاجتماعي كان زاخرا بالكثير من نواحي النشاط الانساني من ميادين العمل والتسلية والترفيه والاعياد والافراح فضلا عن تنوع عناصره السكانية وهذا ما سنتناوله ضمن محاور هذا البحث.
... Show MoreReceived several formats historical kings of old Babylonian era carries connotations military as it chronicled the kings of this era Sunni rule work, was in the forefront of those formulas taken from weapons-grade events have the history of years of their rule, and the keenness of the Kings on the industry that weapon and because it is dedicated to the goddess is the weapon of God, and which pulls the Goddess encouragement and an support them in their wars, they think the Iraqis ancient gods be carrying weapons at the forefront of their armies to fight the enemy with them as well as the receipt of a lot of alliances
لم يكن من السهولة على الباحث في مجال التربية والتعليم تحديد مراحل التعليم في العصر العباسي الأخير او وضع فواصل محددة بين تلك المراحل المختلفة من ذلك العصر، لان التعليم آنذاك كان يتميز بالمرونة التي تتيح للتعليم الحرية المطلقة في اختيار نوع الدراسة والمادة الدراسية التي يريد دراستها.
فكانت المساجد والكتاتيب والمجالس العامة والخاصة هي المؤسسات العلمية الاولى للتعليم عند المسلمين في عهد ال
... Show MoreThe religious forgiving in Islam takes its highest moral value from the law of Muslims (Holy Quran) that practically embodied through the biography of passenger Mohammad (pubh) and the caliphs who behave also according to prophet did to treat with non muslim who were a part of society those are Jewish ,
تعد ظاهرة الصراعات ظاهرة قديمة كقدم الوجود البشري وهذا يطبق على المستوى الدولي مما يجعل الدول الصغرى هي ساحة تصفيات كما هو الحال في سوريا مما يجعل الامن الانساني فيها معدوم