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.
مستخلص البحث أهمية البحث عن طريق إعداد برنامج تدريبي يعتمد هذه الطريقة التدريبية في تطوير التحمل الخاص عن طريق العمل على بناء مستوى جيد من التحمل الخاص لدى اللاعبين الشباب في مرحلة الإعداد الخاص, تحقيق نتائج جيدة على مستوى أداء الواجبات المهارية والخططية المطلوبة منه في أثناء زمن المباراة, حيث ارتأت الباحثة من خلال إعداد برنامج تدريبي إلى رفع مستوى (التحمل الخاص) لدى لاعبي كرة القدم وبالتالي يمكنها أن تساع
... Show MoreThis research is important because of the importance of the subject matter and the implications for the future of development in Iraq. This requires linking the accounting systems with the economic developments. The accounting system we will address in this research is the cost accounting system and its role in determining value added tax. The value added tax and the extent of the relationship with the general accounting principles of cost accounting through which the value added is determined provided the use of a sound and effective cost system.
The problem of research was about knowing the role of cost accounting in determining the value added
... Show Moreيهدف البحث الحالي التعرف على اسباب السرقة لدى تلاميذ المرحلة الابتدائية كما يراها معلموهم ومعلماتهم ، وعن الاساليب المتبعة في معالجة ظاهرة السرقة من قبلهم ، ولقد شملت عينة البحث على ( 200 ) فرداً من معلمي ومعلمات تلاميذ المرحلة الابتدائية في مدينة المكلا للعام الدراسي ( 2004 ـ 2005 ) ، وقد استخدمت الباحثة استبياناً أعدته كأداة للوصول الى اهداف البحث بعد ان تم التأكد من صدقه وثباته ، استخدمت الباحثة معادلة ارتب
... Show MoreThat the government sector takes a big place in the countries and represents a significant role in the face of challenges and adaptation to the important and necessary changes that occur today, including the use of electronic. The electronic computer is a requirement of modern technology in various fields of science, including accounting, Because it derives its entity and content from the spirit of society and its mentality in all its branches, especially the subject of the research system of government accounting Because of its impact on the planning and financial implementation, especially in the preparation and implementation of the State budget, along with expenditure and revenue. Addressing tells us that the first of the sear
... Show MoreAl2O3 and Al2O3–Al composite coatings were deposited on steel specimens using Oxy-acetylene gas thermal spray gun. Alumina was mixed with Aluminum in six groups of concentrations (0, 5, 10,12,15 and 20% ) Al2O3, Specimens were tested for corrosion using Potentiodynamic polarization technique. Further tests were conducted for the effect of temperature on polarization curve and the hardness tests for the coated specimens. At first, Modelling was carried out using MINITAB-19, least square method, as a 2nd degree nonlinear model, bad results were achieved because of the high nonlinearity. Better result w
ABSTRACT Background: One of the challenges to use chlorhexidine is its effect on the amount of microleakage after restoration; however, use of the materials with antibacterial properties after tooth preparation and before restoration has been widespread. The objective of this, in-vitro, study was to evaluate the influence of consepsis (chlorhexidine gloconate disinfectant) application on microleakage in class II cavities restored with light cured composite using universal adhesive system; etch and rinse technique –self etch technique. Materials and Methods: Forty class II cavities were prepared on mesial and distal surfaces of 20 non-carious mandibular third molars. The cavities were divided into four groups; (n =10 for each group).
... Show MoreThis research includes the synthesis of some new N-Aroyl-N \ -Aryl thiourea derivatives namely: N-benzoyl-N \ -(p-aminophenyl) thiourea (STU1), N-benzoyl-N \ -(thiazole) thiourea (STU2), N-acetyl-N ` -(dibenzyl) thiourea (STU3). The series substituted thiourea derivatives were prepared from reaction of acids with thionyl chloride then treating the resulted with potassium thiocyanate to affored the corresponding N-Aroyl isothiocyanates which direct reaction with primary and secondary aryl amines, The purity of the synthesized compounds were checked by measuring the melting point and Thin Layer Chromatography (TLC) and their structure, were identified by spectral methods [FTIR,1H-NMR and 13C-NMR].These compounds were investigated as a
... Show MoreThe research included preparation of new iron(II) complexes with mixed ligands including benzilazine(BA) and semicarbazone ligands {benzilsemicarbazone- BSCH or benzilbis(semicarba-zone)- BBSCH2 or salicylaldehydesemicarbazone- SSCH2 or benzoinsemicarbazone- B'SCH2}.by classical and microwave methods. The resulted complexes have been characterized using chemical and physical methods. The study suggested that the above ligands form ionic complexes having formulae [Fe(SCHi)(BA)(Cl)m](Cl)2-m {where SCH, BSCH, BBSCH2, SSCH¬2 or B'SCH2 ligands; m=1 or 2}. Hexacoordinated mononuclear complexes have been investigated by this study and having octahedral geometries. The effect of laser ray type visible region have been studied on solid ligands and
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