In this research, the effect of multi-walled carbon nanotubes (MWCNTs) on the alumina/chromia (Al2O3/Cr2O3) nanocomposites has been investigated. Al2O3/Cr2O3-MWCNTs nanocomposites with variable contents of Cr2O3 and MWCNTs were fabricated using coprecipitation process and followed by spark plasma sintering. XRD analysis revealed a good crystallinity of sintered nanocomposites samples and there was only one phase presence of Al2O3-Cr2O3 solid solution. Density, Vickers microhardness, fracture toughness and fracture strength have been measured in the sintered samples. The results show that the relative density, microhardness and fracture strength of nanocomposites are significantly improved at low contents of Cr2O3 and MWCNTs. The increase of MWCNT’s content in the nanocomposites has adversely affected due to increasing the tangle and interaction of MWCNTs with each other, which leads to agglomeration in the nanocomposites. Increasing of Cr2O3 content in nanocomposites increases formation of Al2O3-Cr2O3 solid solution that actually requires the high sintering temperature to achieve good densification. The fracture toughness of Al2O3/Cr2O3-MWCNTs nanocomposites was enhanced by increasing the carbon nanotube content.
يتضمن ھذا البحث تحضير وتشخيص بعض المعقدات الفلزية التي تحوي على ليكاندات مختلطة ل (Amoxicillin)( Axn (و(Picoline-٣) (Pic-٣ (وقد تم دراسة ھذه المعقدات بالطرائق الطيفية (اIشعة تحت الحمراء و اIشعة المرئية –فوق البنفسجية والتوصيلية الموIرية والحساسية المغناطيسية ، ومن نتائج ھذه الدراسات التشخيصية امكن اعطاء الصيغة المقترحة العامة لھذه المعقدات و كاIتي
Let M is a Г-ring. In this paper the concept of orthogonal symmetric higher bi-derivations on semiprime Г-ring is presented and studied and the relations of two symmetric higher bi-derivations on Г-ring are introduced.
اعفاء عقود تراخيص الملكية الصناعية من الحظر وفقا للقانون الامريكي و الاوربي
تعرضت المواقع الاثریة في الع ا رق الى النبش والتخریب،وقد أدى ذلك الى أستخ ا رج أعداداً كبیرة من النصوص المسماریة وتهریبها الى خارج الع ا رق. ومن ضمنها نصوص مدینة أ ري- ساكرك، فقد درست مجموعة من هذه النصوص والبالغ عددها ( ١١٥٩ ) نصاً التي نش رت في في هذا البحث قمنا بد ا رسة ( ٤) نصوص مصادرة لصالح المتحف .(Nisaba مجلد ( 15 الع ا رقي ذات مضامین أقتصادیة تتعلق بالحیوانات،ارخت بین السنة الثانیة والاربعین من حكم الملك شولكي وحت
... Show Moreتكمن مشكلة البحث في أن كليات التربية عامةً وكلية التربية /ابن الهيثم خاصة ما زالت تسير وفق أنماط إدارية تقليدية وأن هناك شكوى تلهج بها الألسن في المجتمع المحيط بأن المخرجات التعليمية لا توازي تطلعات المجتمع وتوجهاته المستقبلية، كذلك الأهمية لتطبيق معايير ضمان جودة تحقق المستوى المطلوب لهذه الكلية أسوة بالمعايير العالمية، إذ هدف البحث في معرفة واقع معايير ضمان الجودة في الكلية والانتقال إلى رؤية مستقبلية ل
... Show MoreThe denoising of a natural image corrupted by Gaussian noise is a problem in signal or image processing. Much work has been done in the field of wavelet thresholding but most of it was focused on statistical modeling of wavelet coefficients and the optimal choice of thresholds. This paper describes a new method for the suppression of noise in image by fusing the stationary wavelet denoising technique with adaptive wiener filter. The wiener filter is applied to the reconstructed image for the approximation coefficients only, while the thresholding technique is applied to the details coefficients of the transform, then get the final denoised image is obtained by combining the two results. The proposed method was applied by usin
... Show MoreUrine samples had been gathered from females living in Baghdad city. The sample consisted of 30 females who suffered from U.T.I (Urinary tract infections) and 20 healthy females. The type of urine U.T.I was specified by the emergency lab in Al-Kindy hospital, and alpha tracks were determined by the nuclear track detector CR-39. The concentrations of alpha in 30 urine samples taken from females who had U.T.I ranged from 0.327ppm-1.583ppm, with an average of 0.94965 ppm. The maximum value 1.583 ppm is belonging to females with an aged 57 years old. The results of healthy female concentration ranged from 0.022 ppm-0.459ppm with an average of (0.30855ppm). The findings revealed that alpha emitter concentrations differed from woman to woman,
... Show MoreThe problem of the study lies in the need for standing on the justifications, reasons and difficulties that face the scientific research matter at Baghdad university. The importance of this study lies in the fact of being scientific research one of the most important methods in developing the teaching members performance efficiency which contributes in teachers contact with the modern developments that emerge in work. That matter which reflexe on the educational process and the scientific production in their universities.
And the research goal is summarized in identifying the difficulties that is facing the scientific research at Baghdad university from the point of view of the lecturers, and also to ide
... Show MoreThe objective of this research paper is two-fold. The first is a precise reading of the theoretical underpinnings of each of the strategic approaches: "Market approach" for (M. Porter), and the alternative resource-based approach (R B V), advocates for the idea that the two approaches are complementary. Secondly, we will discuss the possibility of combining the two competitive strategies: cost leadership and differentiation. Finally, we propose a consensual approach that we call "dual domination".