The graphene oxide (GO) is successfully prepared from a purified natural graphite through a pressurized oxidation method. We experimentally demonstrate that GO as an optical media can be used for spatial light modulation based on plasma channels induced by femtosecond pulses. The modulated beam exhibits good propagation properties in free space. It is easy to realize the spatial modulation on t...

We present an improved methodology for a thermal transient method enabling simultaneous measurement of thermal conductivity and specific heat of nanoscale structures with one-dimensional heat flow. The temporal response of a sample to finite duration heat pulse inputs for both short (1 ns) and long (5 ls) pulses is analyzed and exploited to deduce the thermal properties. Excellent agreement has...

n this paper work, sensorless speed control of three phase induction motor is to be carried out using predictive current method and space vector PWM. A closed loop estimation system is proposed with robustness against motor parameters variation is used for the control approach. The novelty of the presented solution is the integration of a simple observer for both speed/flux and current control ...

Three-phase induction motor is an alternating current that most widely used in industry or offices. In principle, the operated at a constant speed, if given load not balanced with its speed of will change. For this reason, one common methods to adjust rotational as desired use Variable Frequency Drive (VFD). The VFD can be controlled by pulse generator PWM (pulse width modulation) and SVPWM (sp...

This paper considers the theoretical and experimental approaches to performance improvement of pneumatic linear actuators. Two On/Off, 3/2 pneumatic valves were used to control the position of a pneumatic piston rod through the closed-loop application of a PWM (Pulse Width Modulation)-sliding mode algorithm. System parameters have been experimentally selected in order to reduce the tracking err...

An analysis is made of the deflected forms assumed by an elastic strip when it is bent and stretched around a rigid drum. A summary is first given of the method of analysis used and the results obtained in a previous study where the drum width is equal to or greater than that of the strip. This work is then extended to the case where the strip width exceeds that of the drum. Defiected forms and...

The Multilevel Inverter topology is advantageous in high-power and power-quality demanding application without use of transformer with reduced harmonic distortion. This paper explain the basic type of Multilevel Inverter such as diode clamped multilevel inverter (neutral point clamped), flywheel capacitor multilevel inverter (capacitor clamped), cascade multilevel inverter also the modulation a...