piezoelectric actuators are widely used in micro manipulation applications. however hysteresis nonlinearity limits accuracy of these actuators. this paper presents a novel approach utilizing a piezoelectric nano-stage as slave manipulator of a teleoperation system. the prandtl-ishlinskii (pi) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. a pas...

in the last two decades, there has been an increasing interest in structural engineering control methods. shape memory alloys and seismic isolation systems are examples of passive control systems that use of any one alone, effectively improve the seismic performance of the structure. characteristics such as large strain range without any residual deformation, high damping capacity, excellent re...

in recent years, need to increase the convenience of trips in railway vehicles causes that train operators and manufacturers focus on reducing the noise level which is sensed by passengers. in this paper, first the state of modeling acoustic noise in cab train is discussed and natural frequencies and acoustic mode shapes are derived and then formulation of acoustic pressure in the cab will be o...

Passive flow control techniques, and particularly vortex generators have been used successfully in a broad range of aero- hydrodynamics applications to alter the characteristics boundary layer separation. This study aims review how such techniques can mitigate extent impact cavitation incompressible flows. focuses first on characterize key physical principles. It then considers complete passive...

in this paper the optimal design of a dissipator made of aluminium and steel and principallysubjected to shear forces and the preliminary results of the characterization tests are described.the device has been designed on the basis of an optimization procedure with the objective tomaximize the energy dissipated in the device. the response of a 3d frame equipped with thedevice and subjected to 7...

In the design of bridges with large spans, the significant values of the moments at the main deck-structure require very heavy members, either in the case of a beam or a truss deck-structure. In order to minimize the influence of bending moments, several applications of passive control of displacements using cable nets are herein proposed. The base for all the proposed systems is the cables sup...

introduction: lead (pb) is a neurotoxin that its different effects on the central nervous system are well-known. previous studies have reported the potent effects of vitamin c on memory.the present study was undertaken to evaluate the protective effects of vitamin c against leadinduced amnesia. methods: male wistar rats were divided into 4 groups: the control (saline), negative control (lead), ...

background & aim : ventilator associated pneumonia (vap) is the most common infections in critical care units, which leads to more length of hospital stay, costs, and high mortality. therefore, prevention is a priority according to clinical guidelines. the aim of this study is determine the effects of passive versus active implementation of vap guidelines on nurses’ performance in critical care...