One of the most important phenomenon that occurs in sheet metal forming processes is the spring-back, which causes several geometrical alterations in the parts. The accurate prediction of springback after bending unloading is the key to the tool design, operation control, and precision estimate concerning the part geometry. This study investigated experimentally the effect of pretension in three rolling direction (0, 90, 45 degree) on the springback behavior of the yellow brass, sheet under V shape bending die. The pre-tension ranges from five different levels starting of 11% to 55% from the total strain in each rolling direction by regular increase of 11 %, then bent on a V-die 90 degree for the springback estimate. From experiment the results revealat that the springback increment with increase pretension ratio and the springback in 45° rolling direction is considerable than the sbringback in 90° rolling direction and the springback in 90° is greater than the sbringback in 0° rolling direction.
الاهمية الاقتصادية للموانىء الحرة مع الاشارة الى المنطقة الاقتصادية الحرة المقترحة في ميناء الفاو
What makes the commercial advertisement distinct is the design structure which is built according to artistic and creative concepts and terms based on the visual and formal interdependence relationships to express the motives of the advertising idea, which is based in its action mechanism on the effective variables, some of which are related to the marketing aspect, and others related to the advertisement aspect. The major aspect is the functional and aesthetic variables, which are represented by the vocabulary of the advertisement area for the open spaces such as the street ads. Its promotional dimension is the active forces in the circulation of commodities and products. Therefore, there would be significant problems the designe
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The research aims to determine the impact of the use of teaching aids for the textbook and graphics teacher illustrations in the collection of historical information and retention, limited research on a sample of students in grade five numbered (68) primary school students of Benin in Baghdad governorate / Breeding Rusafa First, select the researchers of scientific material for students in research Topics are the first and second chapter of the Book of the Arab-Islamic history, set by the Ministry of Education.
And promising targets behavioral and according to the content of subject numbered (100) goal and lesson plans exemplary nu
... Show Moreعلى الرغم من تطور الدراسات التاريخية الخاصة بالمرأة بوصفها حقل معرفي مستقل بدأ منذ نهاية الستينيات من القرن الماضي .ونجاج الكاتبات والباحثات في العديد من بلدان الشرق الاوسط وشمال افريقيا في إعادة المرأة الى التاريخ، الا ان الكتابة التاريخية في العراق مازالت تعاني من نقص كبير في الموضوعات التي تناولت حياة النساء في الماضي. وما يزال الباحثات والباحثين ينظرون الى التاريخ على انه سردية للمعارك والحروب ويو
... Show MoreThe estimation of the parameters of Two Parameters Gamma Distribution in case of missing data has been made by using two important methods: the Maximum Likelihood Method and the Shrinkage Method. The former one consists of three methods to solve the MLE non-linear equation by which the estimators of the maximum likelihood can be obtained: Newton-Raphson, Thom and Sinha methods. Thom and Sinha methods are developed by the researcher to be suitable in case of missing data. Furthermore, the Bowman, Shenton and Lam Method, which depends on the Three Parameters Gamma Distribution to get the maximum likelihood estimators, has been developed. A comparison has been made between the methods in the experimental aspect to find the best meth
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ABSTRACT
Learning vocabulary is a challenging task for female English as a foreign language (EFL) students. Thus, improving students’ knowledge of vocabulary is critical if they are to make progress in learning a new language. The current study aimed at exploring the vocabulary learning strategies used by EFL students at Northern Border University (NBU). It also aimed to identify the mechanisms applied by EFL students at NBU University to learn vocabulary. It also aimed at evaluating the approaches adopted by EFL female students at Northern Border University (NBU) to learn a language. The study adopted the descriptive-analytical method. Two research instruments were developed to collect data namely, a survey qu
... Show Moreان الهدف من هذا البحث هو التعرف على أثر انموذج التفكير النشط في تحصيل طلاب الصف الثاني المتوسط لمادة العلوم و تفـكيرهم البصري. تكونت عينة البحث من (58) طالباً، يتوزعون بين مجموعتين احدهما تجريبية و اخرى ضابطة. تم اعداد اداتين مقننتين احداهما لقياس التحصيل والاخرى لقياس التفــكير البصري، وبعد تطبيق تجربة البحث والحصول على البيانات، التي تمت معالجتها احصائيا باستخدام البرنامج الاحصائي(SPSS)؛ كشفت النتائج عن تفوق
... Show Moreيهدف البحث إلى استقصاء أثر دراسة طالبات كلية العلوم للبنات في جامعة بغداد لمقرر التلوث البيئي في تنمية اتجاهاتهن البيئية، وذلك من خلال التعرّف على النمو في المستوى العام لاتجاهات الطالبات البيئية والكشف عن الفروق الإحصائية في اتجاهاتهن قبل وبعد دراسة المقرر.
وقد تألفت عينة البحث من(50) طالبة من طالبات قسم الفيزياء / الفيزياء الطبية المرحلة الأولى في كلية العلوم للبنات- جامعة بغداد. اعتمدت ا
... Show MoreThe research study aims to investigate the prevalence of the phenomenon of drags and the causes of this phenomenon from the teachers point of view Two hundred Teachers participated in this study Questionnaire was used to collect the data .
The results emphasized the importance 0f the educational counseling through different procedure to prevent drugs abuse . the results also&
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