Electrical Discharge Machining (EDM) is a widespread Nontraditional Machining (NTM) processes for manufacturing of a complicated geometry or very hard metals parts that are difficult to machine by traditional machining operations. Electrical discharge machining is a material removal (MR) process characterized by using electrical discharge erosion. This paper discusses the optimal parameters of EDM on high-speed steel (HSS) AISI M2 as a workpiece using copper and brass as an electrode. The input parameters used for experimental work are current (10, 24 and 42 A), pulse on time (100, 150 and 200 µs), and pulse off time (4, 12 and 25 µs) that have effect on the material removal rate (MRR), electrode wear rate (EWR) and wear ratio (WR). A Minitab software environment was used to adopt Taguchi method to analyze the effect of input on output parameters of EDM. The results of the present work showed that the best of MRR in copper and brass electrodes with (current 42 A, pulse on time 100 µs and pulse off time 25 µs) are (84.355×10-3 g/min) and (43.243×10-3 g/min) respectively, and the MRR predicted by Taguchi are (86.1751×10-3 g/min) in copper electrode by using the parameters with (current 10 A, pulse on time 200 µs and pulse off time 25 µs) and (43.2979×10-3 g/min) in brass electrode at current 42 A, pulse on time 100 µs, and pulse off time 25 µs. The lowest EWR occurs with a value of (1.4510×10-3 g/min) with (current 10 A, pulse on time 100 µs, pulse off time 4 µs) variables when using a copper electrode. The highest WR (2.602508) was found for the brass electrode with (current 24 A, pulse on time 200 µs, pulse off time 4 µs) variables.
رمي البحث الحالي الى تعّرق أثر أنموذج فراير في اکتساب المفاهيم البلاغية عند طالبات الصف الخامس الادبي في مادة البلاغة. ووضع الباحثون الفرضية الصفرية الآتية: "ليس هناک فرق ذو دلالة احصائية عند مستوى (0.05) بين متوسط ودرجات طالبات المجموعة التجريبية اللواتي يدرسن مادة البلاغة بانموذج فراير، ومتوسط درجات طالبات المجموعة الضابطة اللواتي يدرسن المادة نفسها بالطريقة التقليدية (القياسية) في الاختيار البعدي لا کتسا
... Show Moreتهدف الدراسة الحالية إلى معرفة أثر استخدام نموذج ويتلي في اكتساب طلاب الصف الثاني الأساسي لمادة قواعد اللغة العربية. وللتحقق من هدف الدراسة فرضت الفرضيات الصفرية الآتية: الفرضية الصفرية الأولى هي (لا توجد فروق ذات دلالة إحصائية عند مستوى (0.05) بين متوسط درجات المجموعة التجريبية التي درست مادة قواعد اللغة العربية وفق نموذج ويتلي ومتوسط درجات المجموعة الضابطة التي درست مادة قواعد اللغة العربية وفق الطريق
... Show MoreThe current research aims to know on influence strategy (thinking – pairing – sharing) in learning subject of Islamic civilization of Arab and keep it for students 4th class / literary in order to aim of research , the researcher takes measures of experimental method which included selection of experimental designing with partial adjustment in two groups (experimental and controlling) . Experimental group studies according to strategy (thinking – pairing – sharing) , while controlling group studies according to normal way , the researcher choose Zari secondary school for boys in Baghdad intently to run experiment within it. Sample of studying consist of from (64) students , by (32) student in experimental group and (32) students
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The impact of cartoon concepts strategy in the Achievement of the first grade student's average in geography and visual thinking
The study aimed to measure the impact of cartoon concepts strategy to Achievement, visual thinking in the first grade students in the average geographical material.
Find sample consisted of 52 students were divided into two groups, the first experimental studied strategy cartoon concepts and the control group was studied in the traditional manner of parity between the two variables (chronological age, the overall rate, prior knowledge, the degree of intelligence, visual) thinking.
... Show MoreThe present study aims at knowing the effect of instrumental enrichment in the acquisition of geographical concepts for first grade student in intermediate school. The study is restricted in the students of first grade student in intermediate school\ The EducationalDirectorate of Rusafa for academic (2013/2014),for the purpose of achieving the objective, the following hypotheses:
There is no statistical significant different at the level of (0.5) between the scores of the experimental group who study geography according to the instrumental enrichment and the scores of the control group who learned geographical according to the traditional methods.
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... Show MoreThe Journal of Studies and Researches of Sport Education (JSRSE)
Hospitals are part of the service organizations and most importantly at the level of individuals because they are tied to the people health and their daily lives , the nursing service is one of the important services provided by hospitals, and nurses are the human resource that offers this service, from this standpoint the idea of research came to prepare work Scheduling for nurses in a scientific way to improve performance operational for their services and provide efficient service available 24 hours a day, the research use one of the modern and scientific rules of scheduling its “schedule of
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