نتایج جستجو برای: beam

تعداد نتایج: 113050  

Journal: :international journal of nano dimension 0
m. heidari mechanical engineering group, aligudarz branch, islamic azad university, aligudarz, iran

the static pull-in instability of beam-type micro-electromechanical systems is theoretically investigated. two engineering cases including cantilever and double cantilever micro-beam are considered. considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent euler-bernoulli beam model is used based on a modified couple stress theory, c...

Introduction: Beam-angle optimization (BAO) is a computationally intensive problem for a number of reasons. First, the search space of the solutions is huge, requiring enumeration of all possible beam orientation combinations. For example, when choosing 4 angles out of 36 candidate beam angles, C36 = 58905 possible combinations exist.  Second, any change in a   beam 4 config...

Journal: :iranian journal of radiation research 0
m. momennezhad nuclear medicine research center, emam reza hospital, mashhad university of medical sciences, mashhad, iran m.t. bahreyni toosi medical physics research center, mashhad university of medical sciences, mashhad, iran r. sadeghi nuclear medicine research center, emam reza hospital, mashhad university of medical sciences, mashhad, iran h. gholamhoseinian department of medical physics, medical school, mashhad university of medical sciences, mashhad, iran sh. nasseri department of medical physics, medical school, mashhad university of medical sciences, mashhad, iran

background: the presence of a wedge filter in the beam trajectory can modify the beam quality and cause some changes in the dosimetry parameters which are usually difficult to be measured directly and accurately. material and methods: in this study the mcnp-4c monte carlo code was used to simulate the 9 mv photon beam generated by a linear accelerator. upon getting a good agreement between the ...

ژورنال: سنجش و ایمنی پرتو 2013

In order to investigate the possibility of using the T.R.R beam tubes in BNCT, it is necessary to select the best one from three north beam tubes. This beam tube should have more flux and better spectrum compared to others. So, after simulation of the last configuration of reactor’s core (NO.55) by MCNP4C code, the neutron flux and spectrum were calculated at the start, middle, and end of each ...

Journal: :mechanics of advanced composite structures‎ 2015
keivan torabi majid rahi hassan afshari

in this paper, eringen’s nonlocal elasticity and timoshenko beam theories are implemented to analyze the bending vibration for non-uniform nano-beams.  the governing equations and the boundary conditions are derived using hamilton’s principle. a generalized differential quadrature method (gdqm) is utilized for solving the governing equations of non-uniform timoshenko nano-beam for pinned-pinned...

The static pull-in instability of beam-type micro-electromechanical systems is theoretically investigated. Two engineering cases including cantilever and double cantilever micro-beam are considered. Considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent Euler-Bernoulli beam model is used based on a modified couple stress theory, c...

2005
F. Zimmermann

Several techniques have been proposed for compensating the effects of the head-on or long-range beam-beam interaction. These include alternating crossing at several interaction points, electromagnetic wires, electron lenses, and superbunches. I discuss some prominent compensation schemes and their R&D status, with special emphasis on the LHC and its upgrade. 1 HISTORY AND PERSPECTIVE The beam-b...

Journal: :international journal of transportation engineereing 2014
saeed mohammadzadeh seyed ali mosayebi

for dynamic analyses of railway track structures, the algorithm of solution is very important. for estimating the important problems in the railway tracks such as the effects of rail joints, rail supports, rail modeling in the nearness of bridge and other problems, the models of the axially beam model on the elastic foundation can be utilized. for studying the effects of axially beam on the ela...

Jalal Najafi Mohamad Bagher Menhaj Mojtaba Kazemi

The ball and beam system is one of the most popular laboratory setups for control education. In this paper, we design a fuzzy PD cascade controller for a ball and beam system using Asexual Reproduction Optimization (ARO) technique. The ball & beam system consists of a servo motor, a grooved beam, and a rolling ball. This system utilizes a servo motor to control ball’s position on the beam. Chan...

J. Jafari Fesharaki, R. Hamzehpour,

In this paper, controlling the location of the tip of an L-shape beam under gravity field is investigated. The beam is covered with piezoelectric patches. The gravity filed moves the tip of beam downward and the actuators with induced voltage move the tip to the previous location. to optimize the best location and voltages for actuators, the particle swarm optimization algorithm code is develop...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید