In this paper, a microcontroller-based electronic circuit have been designed and implemented for dental curing system using 8-bit MCS-51 microcontroller. Also a new control card is designed while considering advantages of microcontroller systems the time of curing was controlled automatically by preset values which were input from a push-button switch. An ignition based on PWM technique was used to reduce the high starting current needed for the halogen lamp. This paper and through the test result will show a good performance of the proposed system.
The method of powder technology has been utilized in fabrication of machinable
ceramics by the approach of glass-ceramic principles. The crystalline ceramic phases
partially dissolved by host glass while the undissolved part remain responsible for the
machinability by the usual cutting tools. Thus avoiding the unnecessary use of special
dies to cast fully melted composition and initiate recrystallization process. Two types of
machinable ceramics have been successfully prepared, the first with high silica content
and the other with high alumina content. A comparison of their properties and discussed.
يتناول البحث دراسة وتحليل علاقات الهند مع دول مجلس التعاون الخليجي، كونها تحظى بأهمية كبيرة، انطلاقا من الدور المتزايد الذي يطلع به الطرفين على المستوى الإقليمي والدولي، إذ ان الهند من القوى الصاعدة ولها تأثير في التفاعلات الإقليمية والدولية، بينما تتميز دول مجلس التعاون الخليجي بأهمية جيوستراتيجبة واقتصادية كبيرة بالنسبة للقوى الكبرى، نظرا لموقعها الاستراتيجي ولامتلاكها مصادر الطاقة المهمة، و
... Show Moreفي هذا البحث نحاول تسليط الضوء على إحدى طرائق تقدير المعلمات الهيكلية لنماذج المعادلات الآنية الخطية والتي تزودنا بتقديرات متسقة تختلف أحيانا عن تلك التي نحصل عليها من أساليب الطرائق التقليدية الأخرى وفق الصيغة العامة لمقدرات K-CLASS. وهذه الطريقة تعرف بطريقة الإمكان الأعظم محدودة المعلومات" LIML" أو طريقة نسبة التباين الصغرى" LVR" والتي تمثل حسب الصيغة (14.2) الوجه الآخر لطريقة الLIML والتي تشتهر في تقدير معلمات معادل
... Show MoreMany production companies suffers from big losses because of high production cost and low profits for several reasons, including raw materials high prices and no taxes impose on imported goods also consumer protection law deactivation and national product and customs law, so most of consumers buy imported goods because it is characterized by modern specifications and low prices.
The production company also suffers from uncertainty in the cost, volume of production, sales, and availability of raw materials and workers number because they vary according to the seasons of the year.
I had adopted in this research fuzzy linear program model with fuzzy figures
... Show MoreIn this paper, a new form of 2D-plane curves is produced and graphically studied. The name of my daughter "Noor" has been given to this curve; therefore, Noor term describes this curve whenever it is used in this paper. This curve is a form of these opened curves as it extends in the infinity along both sides from the origin point. The curve is designed by a circle/ ellipse which are drawing curvatures that tangent at the origin point, where its circumference is passed through the (0,2a). By sharing two vertical lined points of both the circle diameter and the major axis of the ellipse, the parametric equation is derived. In this paper, a set of various cases of Noor curve are graphically studied by two curvature cases;
... Show Moreيهدف البحث إلى تحديد مستوى الشعور بقلق الكتابة لدى طلاب المرحلة الثانوية في مادة اللغة الإنجليزية كلغة أجنبية، وما إذا كان هناك فرق ذو دلالة إحصائية بين الطلاب والطالبات في الشعور بقلق الكتابة. علاوة على ذلك يهدف البحث إلى التعرف على ما إذا كان هناك فروق ذات دلالة إحصائية بين الطلاب ذوي الكفاءة المنخفضة والعالية من حيث قلق الكتابة، وكذلك التعرف على نوع العلاقة الارتباطية بين كفاءة الطلبة وقلق الكتابة. تم
... Show MoreAbstract :
Researchers have great interest in studying the black box models this thesis has been focused in the study one of the black box models , a ARMAX model which is one of the important models and can be accessed through a number of special cases which models (AR , MA , ARMA, ARX) , which combines method of the time series that depend on historical data and and regression method as explanatory variables addition to that past errors , ARMAX model importance has appeared in many areas of application that direct contact with our daily lives , it consists of constructing ARMAX model several traditional stages of the process , a iden
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