In this paper, an overview of the techniques applied to AC electric propulsion field has been done. Actual study cases of electric ship propulsion schemes are considered. An impartial comparison between three-level converters versus two-level converter from the viewpoint of electric ship propulsion requirements has been done. Diodeclamped three-level converters using direct torque control (DTC)...

[Purpose] This study sought to ascertain whether, in hemiplegic patients, the effect of a wheelchair cushion to suppress pelvic posterior tilt when initiating wheelchair propulsion would continue in subsequent propulsions. [Subjects] Eighteen hemiplegic patients who were able to propel a wheelchair in a seated position participated in this study. [Methods] An adjustable wheelchair was fitted wi...

in this research the simulation of an air independent proton exchange membrane fuel cell (pemfc) propulsion system was taken into consideration. the system consists of several parts including pem fuel cell stack, metal hydride and liquid oxygen (lox) tanks, and also pre-heaters of oxygen and hydrogen gases along with other heat exchangers, to ensure proper operation of system. the heat recovery...

We have studied optical trapping and propulsion of red blood cells in the evanescent field of optical waveguides. Cell propulsion is found to be highly dependent on the biological medium and serum proteins the cells are submerged in. Waveguides made of tantalum pentoxide are shown to be efficient for cell propulsion. An optical propulsion velocity of up to 
6 µm/s on a waveguide with a width of...

“Today’s theories shape tomorrow’s reality” and “tomorrow’s standard of living will depend on the success of today’s theories”. These old truths, having proved themselves so many times in our history, should make us responsible for the implementation, creation, development, distribution of new scientific theories. The idea of Switching Magnetic Energy is obtained from the principle of Electroma...

1. Pulsed Plasma Thruster Pulsed plasma thrusters (PPTs) are expected to be used as a thruster for a small satellite. The PPT has some features superior to other kinds of electric propulsion. It has no sealing part, simple structure and high reliability, which are benefits of using a solid propellant, mainly Teflon (poly-tetrafluoroethylene: PTFE). However, performances of PPTs are generally lo...

Electro hydro dynamic (EHD) and electrostatic propulsion devices were developed in the 1920s by Thomas Townsend Brown. One such device, called a “lifter”, has no moving parts and, in the air, operates on electrical energy. It is a fashionable device and has a very simple structure, basically consisting of a narrow wire electrode and a large, flat one. However, it has a low ratio of propulsion f...

this work focuses on modelling, optimal control and numerical simulation of the ship electric propulsion system provided by a double star synchronous machine. The in-depth analysis of the operation of the propulsion system of the vessel allowed us to model elements of the propulsion system. Thus, a non-linear global model was obtained describing the operation of the entire propulsion system. Th...

The transition to electric propulsion aircraft requires electrical motors or generators with high power density. “zero resistivity” of the superconducting materials could be used in machines produce magnetic fields and reduce use heavy components such as ferromagnetic parts. discovery recent developments High Temperature Superconductors (HTS) technology make machine a serious candidate future a...