4,517 research outputs found
Fluid-loop reaction system
An improved fluid actuating system for imparting motion to a body such as a spacecraft is disclosed. The fluid actuating system consists of a fluid mass that may be controllably accelerated through at least one fluid path whereby an opposite acceleration is experienced by the spacecraft. For full control of the spacecraft's orientation, the system would include a plurality of fluid paths. The fluid paths may be circular or irregular, and the fluid paths may be located on the interior or exterior of the spacecraft
Electric Wheel-Hub-Drive for Aircraft Application
The German Centre for Aerospace, Institute of Vehicle Concepts, has designed and built a prototype of an electric nose wheel drive for its research aircraft Airbus A320. In this paper the requirements and interfaces, the design of the drive and the test results are described
The Design, Manufacture, and Testing of a Novel Adhesion System for a Climbing Vehicle
We present the design and fabrication of a prototype wall-climbing vehicle employing a unique combined locomotion and adhesion system in which the adhesive vacuum is transmitted through moving, perforated treads. Implementing the adhesion/drive system involved a broad range of design challenges, including: developing reliable sealing of sliding and static interfaces, understanding the frictional interactions between the drive treads and various vehicle components and surfaces on which they ride, as well as designing for lightness, manufacturability, and adjustability. The clean sheet design presented in this thesis was taken from concept to functioning prototype in less than 6 months, requiring a considered mix of off-the-shelf components, custom fabrication, and outsourced production. Proof of concept testing is reviewed, including static pressure and force results as well as dynamic vertical surface maneuverability trials
Sites of action of sleep and wake drugs: insights from model organisms
Small molecules have been used since antiquity to regulate our sleep. Despite the explosion of diverse drugs to treat problems of too much or too little sleep, the detailed mechanisms of action and especially the neuronal targets by which these compounds alter human behavioural states are not well understood. Research efforts in model systems such as mouse, zebrafish and fruit fly are combining conditional genetics and optogenetics with pharmacology to map the effects of sleep-promoting drugs onto neural circuits. Recent studies raise the possibility that many small molecules alter sleep and wake via specific sets of critical neurons rather than through the global modulation of multiple brain targets. These findings also uncover novel brain areas as sleep/wake regulators and indicate that the development of circuit-selective drugs might alleviate sleep disorders with fewer side effects
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