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.
İlk çağlarda yaşayan insanların hayal dünyasını tanıtan masallar görünümünde olan destanlar‚ aslında‚ milleylerin tarih öncesi devirlerde başlayan kuruluşlarını‚ inanışlarını‚ erdemlerini‚ fikir ve sanatlarını anlatır.
Destanlar‚ kökü tarihe dayanan olayların, halk gözüyle görülen‚ halk ruhuyla duyulan masallaşmış görüntüleridir. Destanlarda milletlerin dinleri, türlü inanışları‚ Tanrı karşısındaki davranışları, yaşadıkları coğrafyanın özellikleri ile birleşmiş duyguları vardır.
Su köpüğünden yaratılmış‚ bir ağacın karnından doğmuş, ışık kümelerinin içinden çıkmış‚ fil kadar kuvvetli, güneş kadar güzel insanların maceralarını
يعد مفهوم العولمة ظاهرة عالمية كونها نزعة طاغية في الوقت الحالي منسوبة الى العالم ، ولم تدخل بعد قوائم المفردات في القواميس السياسية والاقتصادية . (الأسدي ،2004-ص88).وأن العولمة " Globlization أخذت مدلولان ، الاول يدل على الانفتاح وحرية التفكير ومتابعة الاكتشافات في مختلف المجالات والابتعاد عن الرتابة والروتين . اما الثاني فيدل على سطحية التفكير وحب التغيير لأجل التغيير ونبذ الماض
... Show MoreThe general health of palm trees, encompassing the roots, stems, and leaves, significantly impacts palm oil production, therefore, meticulous attention is needed to achieve optimal yield. One of the challenges encountered in sustaining productive crops is the prevalence of pests and diseases afflicting oil palm plants. These diseases can detrimentally influence growth and development, leading to decreased productivity. Oil palm productivity is closely related to the conditions of its leaves, which play a vital role in photosynthesis. This research employed a comprehensive dataset of 1,230 images, consisting of 410 showing leaves, another 410 depicting bagworm infestations, and an additional 410 displaying caterpillar infestations. Furthe
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طريقة سهلة وبسيطة ودقيقة لتقدير السبروفلوكساسين في وجود السيفاليكسين او العكس بالعكس في خليط منهما. طبقت الطريقة المقترحة بطريقة الاضافة القياسية لنقطة بنجاح في تقدير السبروفلوكساسين بوجود السيفاليكسين كمتداخل عند الاطوال الموجية 240-272.3 نانوميتر وبتراكيز مختلفة من السبروفلوكساسين 4-18 مايكروغرام . مل-1 وكذلك تقدير السيفاليكسين بوجود السبروفلوكساسين الذي يتداخل باطوال موجية 262-285.7 نانوميتر وبتراكيز مخ
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اجري هذا البحث للتعرف على "اثر استخدام طريقة الاكتشاف في تحصيل تلميذات الصف السادس الابتدائي وتنمية المهارات الاجتماعية لديهن في مادة التاريخ" ،واقتصرت عينة البحث الحالي على تلميذات الصف السادس الابتدائي في مدرسة زيد بن ثابت للبنات في مدينة الموصل حيث تكونت عينة البحث من (60)تلميذة تم توزيعهم بشكل متساو الى مجموعتين احداهما تجريبية تدرس باستخدام طريقة الاكتشاف وعددها (30) تلميذة في حين درست المجموع
... Show MoreThe research aimed to diagnose and interpretation of impact nature between Communities of practice dimensions (participation and spreading knowledge, confidence, social capital build) deportation strategic change choices (reengineering business process, business re-structuring, business innovation) in construction companies in the Iraqi Ministry of Construction and Housing, the research tested 4 construction companies working in investing sector in Iraq, the research applied on a sample of 102 persons who participated in Communities of practice distributed in several administrative levels (directors, division directors, project directors and engineers) the research used questionnaire as a main tool for dat
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Data of multispectral satellite image (Landsat- 5 and Landsat-7) was used to monitoring the case of study area in the agricultural (extension and plant density), using ArcGIS program by the method of analysis (Soil adjusted vegetative Index). The data covers the selected area at west of Baghdad Government with a part of the Anbar and Karbala Government. Satellite image taken during the years 1990, 2001 and 2007. The scene of Satellite Image is consists of seven of spectral band for each satellite, Landsat-5(TM) thematic mapper for the year 1990, as well as satellite Landsat-7 (ETM+) Enhancement thematic mapper for the year 2001 and 2007. The results showed that in the period from 1990 to 2001 decreased land area exposed (bare) and increased
... Show MoreThe microstructures of rapidly solidified laser clad layers of laser cladding of Inconel 617 with different nickel-aluminum premixed clad powders are discussed. The effect of different cladding speeds on the microstructures of rapidly solidified laser clad layers is discussed too. The detailed microstructural results showed that different growth mechanisms are produced during rapid solidification. These are planar, cellular, cellular/dendritic and dendritic.
The assessment of a river water’ quality is an essential procedure of monitor programs and is used to collect basic environmental data. The management of integrated water resources in a sustainable method is also necessary to allow future generations to meet their water needs. The main objective of this research is to assess the effect of the Diyala River on Tigris River water quality using Geographic Information System (GIS) technique. Water samples have been collected monthly from November 2017 to April 2018 from four selected locations in Tigris and Diyala Rivers using the grab sampling method. Fourteen parameters were studied which are Turbidity, pH, Dissolved Oxygen, Biological Oxygen Demand, Electrical Conductivi
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Length of plasma generated by dc gas discharge under different vacuum pressures was studied experimentally. The cylindrical discharge tube of length 2m was evacuated under vacuum pressure range (0.1-0.5) mbar at constant external working dc voltage 1500V. It was found that the plasma length (L) increased exponentially with increasing of background vacuum air pressure. Empirical equation has been obtained between plasma length and gas pressure by using Logistic model of curve fitting. As vacuum pressure increases the plasma length increases due to collisions, ionizations, and diffusions of electrons and ions.