نتایج جستجو برای: concentrated source and source over circular region

تعداد نتایج: 17021504  

In this paper, a multi-stage Z-source inverter with high boost factor is proposed. The proposed topology by using the combination of a power supply and Z-source networks are increased the voltage. Regarding voltage increase capability over the wide range, good resistance against electromagnetic noise and immunities against shoot through (ST), this inverter can be used widely in the photovoltaic...

In this paper, a new topology for boost Z-source inverterbased on switched-inductor cell is proposed. The operating modes of the proposed inverter are analyzed and also a suitable control method to generate the trigger signals of the inverter is presented. Having a common earth between the input source and inverter and capability to generate a higher voltage gain by using lower amounts of the d...

Abstract: It is assumed that a beam made of material has a physical nonlinear behavior. This beam is analyzed under the moving concentrated and distributed continuous loads. The vibration equations of motion are derived from the Hamilton's Principle and Euler–Lagrange Equation. In this study, the amplitude of vibration, circular frequency, bending moment, stress and deflection of the beam has b...

Introduction: Dust storms are natural hazards that effects on weather conditions, human health and ecosystem. Atmospheric processes are directly affected by the absorption and diffusion of radiation by dust, and dust in the cloud acts as a nucleus of congestion. The main dust regions in the world are arid topographies that have soil that is vulnerable to erosion and poor vegetation, easily erod...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و علوم انسانی 1394

learning english is very popular all over the world nowadays and it is considered a high prestigious language among citizens of different societies. one of the most important materials for learning a new language are textbooks. the debate that whether learning a new language is natural and neutral or ideological and influential on people’s worldviews, has always been of great importance.

Journal: :بینا 0
علیرضا برادران رفیعی baradaran-rafii ophthalmic research center, shahid beheshti university of medical sciences, tehran, iranتهران- پاسداران- بوستان نهم- خیابان پایدارفرد (خیابان امیر ابراهیمی)- پلاک 23- مرکز تحقیقات چشم طلیعه منتهایی montahai ophthalmic research center, shahid beheshti university of medical sciences, tehran, iranتهران- پاسداران- بوستان نهم- خیابان پایدارفرد (خیابان امیر ابراهیمی)- پلاک 23- مرکز تحقیقات چشم مهدی اصلانی eslani ophthalmic research center, shahid beheshti university of medical sciences, tehran, iranتهران- پاسداران- بوستان نهم- خیابان پایدارفرد (خیابان امیر ابراهیمی)- پلاک 23- مرکز تحقیقات چشم

stem cells located at the limbus ,  are the ultimate source for regeneration of the corneal epithelium in the normal and traumatized states.  when limbal stem cells are dysfunctional or deficient, limbal stem cell deficiency (lscd) develops. its surgical management depends on laterality and severity of corneal-limbal involvement. conventional methods of stem cell transplantation are conjunctiva...

پورمقدس, حسین ,

Ground water is considered as a valuable resource for drinking, agricultural, and industrial uses. As human activities are known to affect water quality, studies of this source are necessary to maintain quality standards. Despite heavy agricultural and industrial activity in the Lenjanat region (Isfahan), there has been no evaluation of ground water quality in this area.In this research project...

In this paper, an unmanned aerial vehicle (UAV) assisted cooperative communication system is studied, wherein a source transmits information to the destination through an energy harvesting decode-and-forward UAV. It is assumed that the UAV can freely move in between the source-destination pair to set up line of sight communications with the both nodes. Since the battery of the UAV may be limite...

Journal: :فلسفه و کلام 0
نجف یزدانی محمد سعیدی مهر سید عباس ذهبی

gaining knowledge of the different existential aspects of human being counts among some the most important issues in psychology (‘ilm al-nafs) and anthropology. in this respect, philosophers in philosophical psychology or knowledge of the self have discussed the different degrees of soul and its faculties, whereas ancient philosophers used to deal with such issues in discussions over natural sc...

Journal: :iranian journal of radiation research 0
m. yazdani department of physics, tarbiat moallem university of sabzevar, sabzevar, iran a.a. mowlavi department of physics, tarbiat moallem university of sabzevar, sabzevar, iran

background: monte carlo determination of tg-43 brachytherapy dosimetry parameters and dose distribution calculation for 131cs source model cs-1 are presented in this study. materials and methods: the dose distribution was calculated around the 131cs model cs-1 located in the center of 30 cm ×30 cm ×30 cm water, and soft tissue phantoms cube using mcnp code by monte carlo method. the percentage ...

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