139,129 research outputs found
Subatmospheric Brayton-cycle Engine Program Review
A solar energy powered electrical generator utilizing a Subatmospheric Brayton cycle engine is examined. The generator consists of a subatmospheric, Brayton-cycle engine and a permanent magnet (PM) alternator. The electrical power is generated by an alternator driven directly by the Brayton-cycle engine rotating group. Features that enhance reliability and performance include air foil bearings on both the Brayton-cycle engine rotating group and the PM alternator, an atmospheric-pressure solar receiver and gas-fired trim heater, and a high temperature recuperator. The subatmospheric Brayton-cycle engine design is based on that of the gas fired heat pump engine
Wire material reduces compressor blade vibration
Wire material /Inconel/ having high friction and low wear characteristics, reduces vibratory stress and prevents compressor blade failure
Resin additive improves performance of high-temperature hydrocarbon lubricants
Paraffinic resins, in high temperature applications, improve strength of thin lubricant film in Hertzian contacts even though they do not increase bulk oil viscosity. Use of resin circumvents corrosivity and high volatility problems inherent with many chemical additives
The kinetic glass transition of the Zr46.75Ti8.25Cu7.5Ni10Be27.5 bulk metallic glass former-supercooled liquids on a long time scale
Viscosity and enthalpy relaxation from the amorphous state into the supercooled liquid state was investigated in the bulk metallic glass forming Zr46.75Ti8.25Cu7.5Ni10Be27.5 alloy below the calorimetric glass transition. At different temperatures, the viscosities relax into states that obey the same Vogel–Fulcher–Tammann relation as the data obtained at higher temperatures in the supercooled liquid. Enthalpy recovery experiments after relaxation in the same temperature range show that the enthalpy of the material reaches values that also corresponds to the supercooled liquid state. The glass relaxes into a metastable supercooled liquid state, if it is observed on a long time scale. Equilibration is possible far below the calorimetric glass transition and very likely even below the isentropic temperature
High-temperature, long-life polyimide seals for hydraulic actuator rods
Two types of polyimide seals are developed for hydraulic actuator rod in low pressure second stage of two-stage configuration. Each seal melts test objectives of twenty million cycles of operation at 534 K. Analytical and experimental study results are discussed. Potential applications are given
Gas lubricant compositions Patent
High temperature gas lubricant consisting of two fluoro-bromo-methane
Filled polymers for bearings and seals used in liquid hydrogen
Filled polytrifluorochloroethylene /PTFCE/ shows better thermal stability, less creep, and higher compressive moduli than filled polytetrafluoroethylene /PTFE/. Bearing and seal materials exhibiting the best characteristics contain a high percentage of PTFCE
Heart Rate Patterns Observed in Medical Monitoring
Medical monitoring of heart rate patterns during conditions of sleep, quiet rest, breath-holding, hypoxia, and increased g forces of aircraft fligh
Metallic film diffusion for boundary lubrication Patent
Metallic film diffusion for boundary lubrication in aerospace engineerin
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