Bobbin friction stir welding (BFSW) is a variant of the conventional friction stir welding (CFSW); it can weld the upper and lower surface of the work-piece in the same pass. This technique involves the bonding of materials without melting. In this work, the influence of tool design on the mechanical properties of welding joints of 6061-T6 aluminum alloy with 6.25 mm thickness produced by FSW bobbin tools was investigated and the best bobbin tool design was determined. Five different probe shapes (threaded straight cylindrical, straight cylindrical with 3 flat surfaces, straight cylindrical with 4 flat surfaces, threaded straight cylindrical with 3 flat surface and threaded straight cylindrical with 4 flat surfaces) with various dimensio

The aim of this research is to employ the roundhouse strategy to study its impact on the students achievement of the 10th grade in physics and their core thinking. After the application of the research experience and gaining data, which was processed statistically using the statistical packages program (SPSS). The results of the researcher revealed the superiority of the students of the experimental group who studied using the roundhouse strategy on the students of the control group who studied the usual method in the achievement test. As results showed that there were statistically significant differences between the average scores of the experimental group and the average scores of the control group students in the core thinking test and

The researcher aims to Diagnose the reality of research variables, strategic leadership and decision support systems, and their impact on crisis management in the General Company for Steel Industries because of their important role in preventing crises and reducing their occurrence for the research company in particular and other companies in general affiliated with the Ministry of Industry and Minerals, as well as clarifying theoretical concepts of research variables As it included the answer to questions related to the research problem, including (Is there an impact of the strategic leadership in managing crises if decision support systems are used), and the researcher adopted the descriptive and analytical approach in its comp

Bragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the

      In developing countries, individual students and researchers are not able to afford the high price of the subscription to the international publishers, like JSTOR, ELSEVIER,…; therefore the governments and/or universities of those countries aim to purchase one global subscription to the international publishers to provide their educational resources at a cheaper price, or even freely, to all students and researchers of those institutions. For realizing this concept, we must build a system that sits between the publishers and the users (students or researchers) and act as a gatekeeper and a director of information: this system must register its users and must have an adequate security to e

Abstract :

       The research aims to diagnose some of the negative phenomena
 ( Counterfiting , Pettifogging , Embezzlement ) that have been detected over the past ( 2010 – 2014 ), a fixed-term part of the national strategy for the fight against corruption launched by the Joint Council for the fight against corruption in Iraq and measuring the application of government control according to the American standard GAO standards and identifying the potential for the application of those standards gap. It has been collecting data and information of special issues of corruption reports and meeting with (42) employees and the use of a checklist has been prepared for thi

 هدفت هذه الدراسة الى التعرف على مدى فاعلية المعلمين في تطبيق نموذج بنائي في تدريس مادة العلوم للصف الثاني الأساسي . وقد استخدمت استراتيجيات نوعية في جمع البيانات وتحليلها . وأوضحت نتائج الدراسة ان المعلمين تقربوا أكثر إلى السلوك البنائي , وابدوا رغبة في استخدام استراتيجيات بنائية في تدريسهم للعلوم . واختتمت الدراسة بمجموعة من التوصيات .

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يعد موضوع التنافس بين القوى الكبرى من الموضوعات المستقبلية المهمة التي تؤشر لنا جانبا من صور العلاقات الدولية التي تتسم بالصراع والتعاون من ناحية، والتعاون والتنافس من ناحية أخرى، وبقدر تعلق الموضوع بالمنطقة العربية التي تعد إحدى أهم المناطق العالمية إثارة في مستوى التفاعلات بأنساقها المختلفة، كونها منطقة لازالت محكومة بعوامل غير مستقرة، تشكل نافذة فاعلة لتدخلات القوى الكبرى الساعية إلى إعادة تشكيل المد

Estimation the unknown parameters of a two-dimensional sinusoidal signal model is an important and a difficult problem , The importance of this model  in modeling Symmetric gray- scale texture image . In this paper, we propose employment Deferential Evaluation algorithm and the use of Sequential approach to estimate the unknown frequencies and amplitudes of the 2-D sinusoidal components when the signal is affected by noise. Numerical simulation are performed for different sample size, and various level of standard deviation to observe the performance of this method in estimate the parameters of 2-D sinusoidal signal model , This model was used for modeling  the Symmetric gray scale texture image and estimating by using

Problem of research as defined, including the following:what is impact organizing of configuration for still life in paintings of students in the Department of Art Education in subject of colors ?Study of well training for organized in painting of still life is necessary for a teacher of art education to contribute effectively to the performance of his letter, so is this research in response to the public goals for a subject of art education. The current research aims to:1. Impact organization of configuration for still life in paintings of students in the Department of Art Education for the first grade in subject of colors2. Role organization of configuration for still life in the painting to serve the educational process in subject of