2,069 research outputs found
Automatic thermal switch Patent
Automatic thermal switch for improving efficiency of cooling gases below 40
Improved thermal isolation for superconducting magnet systems
Closed-cycle refrigerating system for superconductive magnet and maser is operated in vacuum environment. Each wire leading from external power source passes through cooling station which blocks heat conduction. In connection with these stations, switch with small incandescent light bulb, which generates heat, is used to stop superconduction
Multistation refrigeration system
A closed cycle refrigeration (CCR) system is disclosed for providing cooling at different parts of a maser. The CCR includes a first station for cooling the maser's parts, except the amplifier portion, to 4.5 K. The CCR further includes means with a 3.0 K station for cooling the maser's amplifier to 3.0 K and, thereby, increases the maser's gain and/or bandwith by a significant factor. The means which provide the 3.0 K cooling include a pressure regulator, heat exchangers, an expansion valve, and a vacuum pump, which coact to cause helium, provided from a compressor, to liquefy and thereafter expand so as to vaporize. The heat of vaporization for the helium is provided by the maser amplifier, which is thereby cooled to 3.0 K
Transmission line for S-band masers
Transmission-line is coaxial. Its outer conductor is made of thin-wall stainless-steel tube; inside is plated with 0.0025 mm copper and 0.0003 mm gold. This combination gives little microwave loss and adequate thermal isolation
Spiraled channels improve heat transfer between fluids
Spiral flow channels increase heat transfer between two fluids in a countercurrent heat exchanger of given volume. The heat exchanger is constructed by connecting a spiraled bellows-shaped ducting between two concentric cylindrical tubes
Automatic thermal switch accelerates cooling-down of cryogenic system
Automatic switch uses short stainless steel tube with copper heat sinks to accelerate helium gas cooling and provides good thermal conductivity and good thermal insulation
The impact of local variations in a temperate maritime climate on building energy use
This is the author accepted manuscript. The final version is available from Taylor & Francis (Routledge) via the DOI in this record.We investigate the impact of local climatic variations on the energy performance of
buildings by conducting simulations using weather files generated from high-resolution
weather measurements covering 33 stations within a 77km2 area in southern Vancouver
Island, British Columbia, Canada. Weather files were created by resampling and
cleaning the data and applying appropriate models to obtain unmeasured values. The
difference in microclimate has been analysed statistically and graphically; average
annual temperature varies by around 1°C, and at certain times there is a 6°C variation
across the (very small) region.
Building energy simulations of a small naturally-ventilated office building and a larger
air-conditioned building were performed using EnergyPlus for all weather files.
Significant variation is found spatially and temporally which would have substantial
implications for building design and energy use. The variation in annual heating energy
use is +/- 5% of the mean, equivalent to 18kWh/m2
/a, with even greater relative
variation in cooling energy use.Engineering and Physical Sciences Research Council (EPSRC) - The creation of localized current and future weather for the built environment (EP/M022099/1
The Quantum Mechanics of Hyperion
This paper is motivated by the suggestion [W. Zurek, Physica Scripta, T76,
186 (1998)] that the chaotic tumbling of the satellite Hyperion would become
non-classical within 20 years, but for the effects of environmental
decoherence. The dynamics of quantum and classical probability distributions
are compared for a satellite rotating perpendicular to its orbital plane,
driven by the gravitational gradient. The model is studied with and without
environmental decoherence. Without decoherence, the maximum quantum-classical
(QC) differences in its average angular momentum scale as hbar^{2/3} for
chaotic states, and as hbar^2 for non-chaotic states, leading to negligible QC
differences for a macroscopic object like Hyperion. The quantum probability
distributions do not approach their classical limit smoothly, having an
extremely fine oscillatory structure superimposed on the smooth classical
background. For a macroscopic object, this oscillatory structure is too fine to
be resolved by any realistic measurement. Either a small amount of smoothing
(due to the finite resolution of the apparatus) or a very small amount of
environmental decoherence is sufficient ensure the classical limit. Under
decoherence, the QC differences in the probability distributions scale as
(hbar^2/D)^{1/6}, where D is the momentum diffusion parameter. We conclude that
decoherence is not essential to explain the classical behavior of macroscopic
bodies.Comment: 17 pages, 24 figure
Enclaves in the Cadillac Mountain Granite (Coastal Maine): Samples of Hybrid Magma from the Base of the Chamber
The Cadillac Mountain intrusive complex is dominated by the Cadillac Mountain granite and a 2–3 km thick section of interlayered gabbroic, dioritic and granitic rocks which occurs near the base of the granite. The layered rocks record hundreds of injections of basaltic magma that ponded on the chamber floor and variably interacted with the overlying silicic magma. Magmatic enclaves, ranging in composition from 55 to 78 wt % SiO2, are abundant in granite above the layered mafic rocks. The most mafic enclaves are highly enriched in incompatible elements and depleted in compatible elements. Their compositions can be best explained by periodic replenishment, mixing and fractional crystallization of basaltic magma at the base of the chamber. The intermediate to silicic enclaves formed by hybridization between the evolved basaltic magma and resident silicic magma. There is little evidence for significant exchange between enclaves and the enclosing granite. Instead, hybridization apparently occurred between stratified mafic and silicic magmas at the base of the chamber. Enclaves in a restricted area commonly show distinctive compositional characteristics, suggesting they were derived from a discrete batch of hybrid magma. Enclaves were probably dispersed into a localized portion of the granitic magma when replenishment or eruption disrupted the intermediate layer
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