Electrochemical Grinding (ECG) process is a mechanically assisted electrochemical process for material processing. The process is able to successfully machine electrically conducting harder materials at faster rate with improved surface finish and dimensional control. This research studies the effect of applied current, electrolyte concentration, spindle speed and the gap between workpiece and tool on hardness and material removal rate during electrochemical grinding for stainless steel 316. The characteristic features of the electrochemical grinding process are explored through Taguchi-design-based experimental studies. The better hardness can be obtained at 10 A of the current, 150 g/l of the electrolyte concentration, 0.3 mm of gap and spindle speed of 180 rpm, and the maximum material removal rate can be obtained at 40 A of the current, 250 g/l of the concentration, 0.2 mm of a gap and 180 rpm of spindle speed.
Double skin ventilated roof is one of the important passive cooling techniques that aims to reduce solar heat gain through roofs by reducing both the conduction and convection heat transfer from the roof to the ceiling of buildings. On the other hand, radiant barrier system (RBS) is very powerful in blocking the radiation heat transfer between the two skins. In this research,the effect of placing a thin layer of aluminium foil at different locations on the thermal insulation performance of a double skin ventilated roof model is investigated experimentally and the optimum location that transmits less heat flux from the lower skinis specified.The model is made of two parallel inclined galvanized steel plates. Galvanized steel has been used
... Show Moreنجدّ القرآن الكريم والحديث النبوي الشري يقدمان أر ى ميامين لمقيم الداعية
إلى إ امة مجتمع متماسك البنيان
ناولت هذه الدراسة إحدى الشخصيات الأمريكية التي تأثرت بواقع السود. كان بوكر تاليافيرو واشنطن أحد الأمريكيين السود ، الذين ولدوا في ظل العبودية وتعرضوا للاضطهاد بعد إلغاء حقوق التصويت وإطلاق قوانين جيم كرو من قبل الولايات الجنوبية. ورأى واشنطن خلال عمليات إعادة الإعمار أحوال السود وكيف كانت معاناتهم قبل الحرب الأهلية في ظل ظروف العبودية التي شملت الإذلال ، والحرمان من حقوقهم المدنية والسياسية، فيما لم يختلف
... Show Moreتعد دراسة التراث العلمي العربي من الدراسات التي تلقي الضوء على التطور التاريخي للعلوم العربية وما أنجزته العقلية العربية في هذا الميدان للمدة التاريخية التي ابتدأت بعصر صدر الإسلام وانتهت بالخلافة ويرى الكثير من العلماء سواء كان
The recent escalation in Southeast Asia showed that the region is on the verge of political and economic crises through the United States and its allies imposing economic sanctions against China, and a military escalation that may begin with China’s invasion of Taiwan, especially since two-thirds of the American forces in the world are located in the Taiwan Strait and the South China Sea.
The United States claims that it is ready to defend the island of Taiwan in the event of the start of Chinese military operations, but the reality shows that the United States supports Taiwan militarily by equipping it with modern weapons to defend itself. Supporting Taiwan economically by engaging it in trade agreements with US allies in the r
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يُعدّ الأشخاص ذوو الإعاقة أكبر أقلية في العالم وأكثرها حرمانًا، حيث تشير الإحصاءات إلى أن نحو مليار شخص، أي ما يعادل 15% من سكان العالم، يعانون من بعض أشكال الإعاقة، مع تزايد معدلاتها في البلدان النامية. وتشير الدراسات العلمية إلى أن ذوي الإعاقة قادرون على مزاولة العمل بإتقان ومثابرة، بل وقد تتفوق مهاراتهم أحيانًا على مهارات الأشخاص غير المعاقين، إذا تم اختيار العمل المناسب لقدراتهم ومواهبهم. كما أن حق العمل
... Show Moreobjective of this research is to identify some of the obstacles that face secondary school teachers of the Arabic language courses in using modern teaching methods in class.
The research focuses on secondary school teachers of the Arabic language courses at the central region of Nineveh Governorate for the school year (2008-2009). 30 teachers out of 792, were randomly chosen to apply the research tool upon.
To fulfill the objective of this research, the researcher first surveyed a number of teachers , he then identified four categories of obstacles; obstacles related to school administrative system and environment, the teacher, courses and pupils, and the nature of teaching method
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The letters of the Al-Safa Brothers contain many tales, in which each story is a literary text that is independent from the other texts, but it constitutes a unified entity in its entirety, because these stories contain recurring structural elements that go into building each one of them. The stories - the subject of the analysis - were not keen on something that was keen on adhering to the Sufi vision and its apparent effect on the tales of the messages, starting with the announcement of the narration to the narrator and his attempt to persuade the recipient of the truth of what is being told and its realism, and made him believe it. The stories correspond to the formal construction of the ideal style defined by th
... Show Moreتعمل البنوك والمؤسسات المالية كوسيط مالي بين أصحاب المدخرات والودائع من جهة ومستخدمي هذه الأموال من جهة أخرى، وممارسة هذه الوساطة المالية بين الطرفين توضح العلاقة التي ينشأ عنها الائتمان، فالائتمان علاقة بين طرفين أولهما تزيد موارده على احتياجاته وهم (المدخرون) والثاني تزيد احتياجاته على موارده وهم (المقترضون)، وطبيعة العلاقة التي تنشأ بينهما تأخذ أحد شكلين: مباشر دون وساطة من أي طرف خارجي، أو غير مباشر عن
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Social reform is the main pillar of the organization of societies. Therefore, all religions and theories were directed to focus on this aspect as the most important element for the development of economic and cultural development. In addition to the analysis and application of the Islamic Sharia, he did not present a theory, but offered real solutions and remedies to the crises in our Arab and Islamic societies alike, despite the criticism directed at him. Z his opinions.<
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