Inspired by the natural design of bacterial flagella, we report artificial bacterial flagella ABF that have a comparable shape and size to their organic counterparts and can swim in a controllable fashion using weak applied magnetic fields. The helical swimmer consists of a helical tail resembling the dimensions of a natural flagellum and a thin soft-magnetic “head” on one end. The swimming loc...

Models of propulsion motors, generators, gas turbines, and power converters are used to determine weights and volumes, evaluate designs, and predict performance of power system components for all-electric navy ships. The finite element analysis method using 3D CAD models is used to validate designs and predict performance under prescribed constraints that simulate realistic operational conditio...

A problem of great concern in aviation and submarine propulsion is the control of the boundary layer and, in particular, the methods to extend the laminar region as a means to decrease noise and fuel consumption. In this paper we study the flow of air along an airfoil when a layer of ionized gas and a longitudinal electric field are created in the boundary layer region. By deriving scaling solu...

Over 2500 active satellites are in orbit as of October 2020, with an increase ~1000 smallsats the past two years. Since 2012, over 1700 have been launched into orbit. It is projected that by 2025, there will be 1000 per year. Currently, these do not sufficient delta v capabilities for missions beyond Earth They confined to their pre-selected and most cases, they cannot avoid collisions. Propuls...

Objective. To compare the energy expenditure of two types of manual wheelchair propulsion. Design. Experimental and comparative design using matched controls. Background. A new manual wheelchair propulsion technique is proposed to minimize the overload exerted on the upper limb during the classical propulsion. The energy cost and other parameters of this new propulsion technique were evaluated....

During wheelchair propulsion, in order to apply power to the pushrim effectively, shoulder and trunk stabilization is needed to control arm movements and the consequent transfer of power from the limbs through to the pushrim. Available trunk control may be one of the most important force-generating mechanisms during wheelchair propulsion, particularly when an individual is fatigued or propellin...

Photofission enables a unique capability for the domain of non-chemical space propulsion. An ultra-intense laser enables the capacity to induce nuclear fission through the development of bremsstrahlung photons. A fundamental architecture and performance analysis of a photofission pulsed space propulsion system through the operation of an ultra-intense laser is presented. A historical perspectiv...

Abstract This paper studies the electromagnetic field used for driving a vibro-impact capsule prototype small bowel endoscopy. Mathematical models of and system are introduced, analytical solution magnetic force applied on is derived verified by experiment. The impact between inner mass body also compared via numerical simulation experimental testing. By comparing capsule’s progressions under d...

The concept of multilevel inverters, introduced about 20 years ago entails performing power conversion in multiple voltage steps to obtain improved power quality, lower switching losses, better electromagnetic compatibility, and higher voltage capability. The benefits are especially clear for medium-voltage drives in industrial applications and are being considered for future naval ship propuls...