34,203 research outputs found
A rotating electrical transfer device
The design, development, and performance characteristics of two roll ring configurations - a roll ring being a device used in transferring electrical energy across a continuously rotating or oscillating interface through one or more flexible rolling contacts, or flexures are described. Emphasis is placed on the design problems and solutions encountered during development in the areas of flexure fatigue, contact electroplating, electrical noise, and control of interface geometry. Also, the present status of each configuration is summarized
Gravity-assisted trajectories for unmanned space exploration
Gravity assistance to modify heliocentric trajectories of manned space probe
Long-term material compatibility testing system
System includes procedure for hermetically sealing solid materials and fluids in glass ampoule and use of temperature-controlled facility containing sample holder, which permits sample containers to be retrieved safely and conveniently. Solid material and fluid are sealed within chemically-clean glass ampoule according to highly detailed procedure
Canine liver transplantation under nva cyclosporine versus cyclosporine
The immunosuppressive qualities and other features of a new cyclosporine (CsA) analogue, Nva 2-cyclosporine (Nva 2-CsA) were examined using canine orthotopic liver allografts. The mean survival time was 11.8±9.6 (SD) days in dogs without treatment, 60.8±34.4 days with Nva 2-CsA and 65.1±33.0 days with CsA. Functional abnormalities indicating toxic side effects were not noted either with Nva 2-CsA or with CsA. Using the same oral dose, the rate of blood level rise and the amount of the rise were greater with Nva2-CsA. Histopathologically, Nva2-CsA the treatment was associated with the same degree of hydropic vocuolation in the pars recta of the proximal tubules as CsA treatment. Thus, in the dog, Nva2-CsA had identical immunosuppressive properties as CsA, with no functionally detectable toxicity affecting the liver and kidney. © 1986 by The Williams & Wilkins Co
Control in the technical societies: a brief history
By the time control engineering emerged as a coherent body of knowledge and practice (during and just after WW2) professional engineering societies had existed for many decades. Since control engineering is an interdisciplinary branch of the profession, new sections devoted to control were quickly established within the various existing technical societies. In addition, some new bodies devoted specifically or primarily to control were established. This article, a revised version of a paper presented at the IEEE 2009 Conference on the History of Technical Societies, describes how control engineering as a distinct branch of engineering became represented in technical societies in a number of countries
Understanding the Structural Scaling Relations of Early-Type Galaxies
We use a large suite of hydrodynamical simulations of binary galaxy mergers
to construct and calibrate a physical prescription for computing the effective
radii and velocity dispersions of spheroids. We implement this prescription
within a semi-analytic model embedded in merger trees extracted from the
Bolshoi Lambda-CDM N-body simulation, accounting for spheroid growth via major
and minor mergers as well as disk instabilities. We find that without disk
instabilities, our model does not predict sufficient numbers of intermediate
mass early-type galaxies in the local universe. Spheroids also form earlier in
models with spheroid growth via disk instabilities. Our model correctly
predicts the normalization, slope, and scatter of the low-redshift size-mass
and Fundamental Plane relations for early type galaxies. It predicts a degree
of curvature in the Faber-Jackson relation that is not seen in local
observations, but this could be alleviated if higher mass spheroids have more
bottom-heavy initial mass functions. The model also correctly predicts the
observed strong evolution of the size-mass relation for spheroids out to higher
redshifts, as well as the slower evolution in the normalization of the
Faber-Jackson relation. We emphasize that these are genuine predictions of the
model since it was tuned to match hydrodynamical simulations and not these
observations.Comment: Submitted to MNRA
Dairy Cows Like Ground Corn in Grass Silage
Roughages are a good, and cheap, source of essential nutrients for dairy cows. One possible way to increase roughage consumption is to add some ground corn to grass silage at ensiling or to feed concentrates on top
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