it has been revealed that the surface stress effect plays an important role in the mechanical behavior ofstructures (such as bending, buckling and vibration) when their dimensions are on the order ofnanometer. in addition, recent advances in nanotechnology have proposed several applications fornanoscale shells in different fields. hence, in the present article, within the framework of surfaceel...

gyroscopes are used as rotation rate sensors. conventional gyroscopes are heavy and bulky, which creates important problems regarding their usage in different applications. micro-gyroscopes have solved these problems due to their small size. the beam micro-gyroscope is one of the popular types of inertial sensors. their small dimensions and low energy consumption are key reasons for their popul...

seismic waves are filtered as they pass through soil layers, from bedrock to surface. frequencies and amplitudes of the response wave are affected due to this filtration effect and this will result in different ground motion characteristics. therefore, it is important to consider the impact of the soil properties on the evaluation of earthquake ground motions for the design of structures. soil ...

nowadays, different methods are used to solve optimization problems which ,one of the newest is bco method that are inspired by the nature and derived from the social life of bees of these methods can be noted that bco is derived from the social life of bees. we use in this paper fuzzy logic for bee‟s decision stage. at the end, we solve two different problem that have already been solved by es...

with speed increasing in high-speed trains, due to limitations of other types of brakes, aerodynamic brake has become an important braking method. in this task to make better use of brake’s panel different configurations are examined and the best panel shape which provides the reasonable drag coefficient is introduced. the results of simulations are carried out with the computational fluid dyna...

the natural frequency and pull-in instability of clamped-clamped nano-actuators in the presence of a dielectric layer are analyzed. the influence of the presence of casimir force, electrostatic force, fringing field effect, axial force, stretching effects and the size effect are taken into account. the governing equation of the dynamic response of the actuator is transformed in a non-dimensiona...

in this paper, a structural damage identification method (sdim) is developed for plate-like structures. this method is derived using dynamic equation of undamaged/damaged plate, in which local change in flexural rigidity is characterized utilizing a damage distribution function. the sdim requires to modal data in the intact state and frequency response of damage state where most of vibration ba...

this study introduces the differential transform method (dtm) to analyse the free vibration response of a rotating, closed section, composite, timoshenko beam which features material coupling between flapwise bending and torsional vibrations due to ply orientation. the governing differential equations of motion are derived using hamilton’s principle and solved by applying dtm. the natural frequ...

introduction: the feedback provided by auditory apparatus equips normal hearing people with an important controlling mechanism over the speech production processes. the speech of hearing-impaired children is both perceptually and acoustically abnormal. this study tried to compare the formant frequencies of three long vowels in persian-speaking children who used cochlear implant and those who we...