Results 31 to 40 of about 491,279 (390)

A Review of Concepts, Benefits, and Challenges for Future Electrical Propulsion-Based Aircraft

open access: yesAerospace, 2020
Electrification of the propulsion system has opened the door to a new paradigm of propulsion system configurations and novel aircraft designs, which was never envisioned before.
Smruti Sahoo, Xin Zhao, K. Kyprianidis
semanticscholar   +1 more source

Propulsion on a superhydrophobic ratchet [PDF]

open access: yesScientific Reports, 2014
Liquids in the Leidenfrost state were shown by Linke to self-propel if placed on ratchets. The vapour flow below the liquid rectified by the asymmetric teeth entrains levitating drops by viscosity. This effect is observed above the Leidenfrost temperature of the substrate, typically 200°C for water.
Dupeux, Guillaume   +4 more
openaire   +5 more sources

Efficiency of fish propulsion [PDF]

open access: yesBioinspiration & Biomimetics, 2015
It is shown that the system efficiency of a self-propelled flexible body is ill-defined unless one considers the concept of quasi-propulsive efficiency, defined as the ratio of the power needed to tow a body in rigid-straight condition over the power it needs for self-propulsion, both measured for the same speed. Through examples we show that the quasi-
Maertens, Audrey   +2 more
openaire   +6 more sources

Genetic algorithm-based multiple moving target reaching using a fleet of sailboats

open access: yesIET Cyber-systems and Robotics, 2019
This study addresses the problem of Dynamic Travelling Salesman Problem for a multi-agent system using a fleet of sailboats. A genetic algorithm (GA) is proposed, which attributes to each agent a varying number of targets to be collected.
Viel Christophe   +4 more
doaj   +1 more source

Targeting Paretic Propulsion and Walking Speed With a Soft Robotic Exosuit: A Consideration-of-Concept Trial

open access: yesFrontiers in Neurorobotics, 2021
Background: Soft robotic exosuits can facilitate immediate increases in short- and long-distance walking speeds in people with post-stroke hemiparesis.
Franchino Porciuncula   +11 more
doaj   +1 more source

The Kinky Propulsion of Spiroplasma [PDF]

open access: yesCell, 2005
Bacteria have evolved many different means of generating movement. In this issue of Cell, Shaevitz et al. (2005) describe the swimming movement of a helical bacterium called Spiroplasma. They discover that Spiroplasma propels itself by generating two temporally distinct kinks that travel the length of the bacterium. These results point to the existence
Charles W. Wolgemuth, Nyles W. Charon
openaire   +3 more sources

Comparison of Active Drag Using the MRT-Method and the MAD-System in Front Crawl Swimming

open access: yesProceedings, 2018
The purpose of this study was to compare the active drag values estimated by the MRT-method and the MAD-system. Six male competitive swimmers participated in this study and performed front crawl with arms only condition.
Kenzo Narita   +3 more
doaj   +1 more source

Analysis of Energy Utilization and Losses for Jet-Propelled Vehicles

open access: yesAerospace, 2021
The global control volume-based energy utilization balance for an aerospace vehicle is extended to allow for the analysis of jet-propelled vehicles.
Mohammad Abbas, David W. Riggins
doaj   +1 more source

Swimmers’ Effective Actions during the Backstroke Start Technique

open access: yesSensors, 2023
The analysis of the external forces of swimming starts has revealed how swimmers propel themselves out of the block, but data should be properly interpreted to fully understand force-generation mechanisms.
Karla de Jesus   +7 more
doaj   +1 more source

Perspectives, frontiers, and new horizons for plasma-based space electric propulsion

open access: yesPhysics of Plasmas, 2020
There are a number of pressing problems mankind is facing today that could, at least in part, be resolved by space systems. These include capabilities for fast and far-reaching telecommunication, surveying of resources and climate, and sustaining global ...
I. Levchenko   +8 more
semanticscholar   +1 more source

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