A new scheme of plasma-mediated thermal coupling has been implemented which yields the temporal distributions of the thermal flux which reaches the metal surface, from which the spatial and temporal temperature profiles can be calculated. The model has shown that the temperature of evaporating surface is determined by the balance between the absorbed power and the rate of energy loss due to evaporation. When the laser power intensity range is 107 to108 W/cm2 the temperature of vapor could increase beyond the critical temperature of plasma ignition, i.e. plasma will be ignited above the metal surface. The plasma density has been analyzed at different values of vapor temperature and pressure using Boltzmann’s code for calculation of electron distribution function. This analysis has been used to determine the temporal distribution of the net heat flux, which reaches the solid surface. The net heat flux has been proved to vanish at high plasma density. Accordingly the temporal and spatial distributions of temperature profiles within the solid metal have been modeled depending upon the net heat flux which reaches the target surface.
مشكلة البحث:
يبقى الفن ولا زال في جميع حالات التعاقب البشري ومراحل التطور الانساني الاكثر انطلاقة وتميزاً في التعبير عن واقع الانسان وعن مشاعره وانفعالاته وافكاره ذات الصلة بتأثيرات البيئة المحيطة به.
والفن ولاسيما (الرسم) يمثل وسيلة من وسائل التعبير الفني بل يكاد يكون الرسم وسيلة الانسان الاولى التي عبر فيها بخطوط مرئية عن مجالات حياته وعلاقته بالبيئة التي عاش فيها، ويقينا
... Show MoreIn this subject article analyzed features of a sports indifferent countries during , article analyzed features of a sports media in different countries between social change politcheskih , transformation thematic area dedicated sports periodicals and the influence of these media on the formation of national identity .
Subject of comparative analysis research are sports print media in Ukraine and Iraqi Kurdistan .And highlight the sports as one of modem Kurdish journalism in lraqi Kurdistan that emerged after the spring in 1991 which took her privacy in the field of journalism , and analysis with sports journalism in the era of the independent state of Ukнаraine in the early nineties of the past century .
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Background: clinically significant macular edema (CSME) is the commonest cause of visual loss in patients with diabetes mellitus and laser focal photocoagulation is the golden standard for treating it. Patients and Methods: A frequency doubled Nd: YAG laser was used to treat all eyes included in this study with diabetic maculopathy. Thirty eyes of three insulin dependent and twenty six non insulin dependent diabetic Iraqi patients were included. The study involved twenty six males, three females and followed for one year. Their ages were ranging between 36- 59 years, all of them from patients attending ophthalmic out-patient department in the medical city in the period between January 2005 and June 2006. Eyes divided in to two groups (fifte
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In this study, simply supported reinforced concrete (RC) beams were analyzed using the Extended Finite Element Method (XFEM). This is a powerful method that is used for the treatment of discontinuities resulting from the fracture process and crack propagation in concrete. The mesoscale is used in modeling concrete as a two-phasic material of coarse aggregate and cement mortar. Air voids in the cement paste will also be modeled. The coarse aggregate used in the casting of these beams is a rounded aggregate consisting of different maximum sizes. The maximum size is 25 mm in the first model, and in the second model, the maximum size is 20 mm. The compressive strength used in these beams is equal to 26 MPa.
The subje
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The main objective of this study is to determine whether the use of He-Ne Laser (632.8 nm wavelength and power 0.5 mW) is an eligible and effective tool to kill or reduce the cell viability of Candida albicans isolated from complete upper dentures. Twenty one swabs were taken from the complete upper dentures. Only six swabs showed positive cultures for C. albicans. The isolate was divided into two groups, group I was not irradiated (control), and group II was irradiated by He-Ne Laser for different periods (10, 15, 20, and 30) min. After irradiation, the results showed a significant reduction in the viable cell count and colonies diameters especially at exposure periods 10 and 15 min. Although the low power He-Ne Laser was not eradicating t
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دراسة حاكمية الجامعات وأثرها في القرار الاستراتيجي