60 research outputs found
Investigation of 75-millimeter-bore Deep-groove Ball Bearing Under Radial Load at High Speeds II : Oil Inlet Temperature, Viscosity, and Generalized Cooling Correlation
Effect of bronze and nodular iron cage materials on cage slip and other performance characteristics of 75-millimeter-bore cylindrical roller bearings at DN values to 2x10 to the sixth power
Comparison of Performance of Experimental and Conventional Cage Designs and Materials for 75-millimeter-bore Cylindrical Roller Bearings at High Speed
The results of two investigations, one to determine the relative merits of four experimental and two conventional design 75-millimeter-bore (size 215) cylindrical roller bearings and one to determine the relative merits of nodular iron and bronze as cage materials for this size and type of bearing, are presented in this report. Nine test bearings were operated over a range of dn values (product of bearing bore in mm and shaft speed in r.p.m) from 0.3 x 10(6) to 2.3 x 20(6), radial loads for 7 to 1613 pounds, and oil flows from 2 to 8 pounds per minute with a single-jet circulatory oil feed. Of the six bearings used to evaluate designs, four were experimental types with outer-race-riding cages and inner-race-guided rollers, and two were conventional types, one with outer-race-guided rollers and cage and one with inner-race-guided rollers and cage. Each of these six test bearings was equipped with a different design cage made of nodular iron. The experimental combination of an outer-race-riding cage with a straight-through outer race and inner-race-guided rollers was found to give the best over-all performance based on limiting dn values and bearing temperatures
Preliminary Comparison of 17- and 75-millimeter-bore Cageless Cylindrical Roller Bearings with Conventional Cylindrical Roller Bearings at High Speeds
Preliminary results at high speeds indicate lower bearing temperatures, less internal bearing wear, and greater reliability of the conventional, cage-type cylindrical roller bearings than of either full-complement or special cageless roller bearings of the types investigated, although the latter bearing types have been operated successfully to DN values of 1.0 X 10 superscript 6
Investigation of 75-millimeter-bore Deep-groove Ball Bearings Under Radial Load at High Speeds I : Oil-flow-studies
Influence of Lubricant Viscosity on Operating Temperatures of 75-millimeter-bore Cylindrical-roller Bearing at High Speeds
Self-aligned fabrication process for silicon quantum computer devices
We describe a fabrication process for devices with few quantum bits (qubits),
which are suitable for proof-of-principle demonstrations of silicon-based
quantum computation. The devices follow the Kane proposal to use the nuclear
spins of 31P donors in 28Si as qubits, controlled by metal surface gates and
measured using single electron transistors (SETs). The accurate registration of
31P donors to control gates and read-out SETs is achieved through the use of a
self-aligned process which incorporates electron beam patterning, ion
implantation and triple-angle shadow-mask metal evaporation
Three Key Questions on Fractal Conductance Fluctuations: Dynamics, Quantization and Coherence
Recent investigations of fractal conductance fluctuations (FCF) in electron
billiards reveal crucial discrepancies between experimental behavior and the
semiclassical Landauer-Buttiker (SLB) theory that predicted their existence. In
particular, the roles played by the billiard's geometry, potential profile and
the resulting electron trajectory distribution are not well understood. We
present measurements on two custom-made devices - a 'disrupted' billiard device
and a 'bilayer' billiard device - designed to probe directly these three
characteristics. Our results demonstrate that intricate processes beyond those
proposed in the SLB theory are required to explain FCF.Comment: 17 pages, 4 figures, in press for Physical Review
Siblings of children with autism:The Siblings Embedded Systems Framework
Purpose of review: a range of interacting factors/mechanisms at the individual, family, and wider systems levels influences siblings living in families where one sibling has autism. We introduce the Sibling Embedded Systems Framework which aims to contextualise siblings’ experience and characterise the multiple and interacting factors influencing family and, in particular, sibling outcomes.Recent findings: findings from studies that have reported outcomes for siblings of children with autism are equivocal, ranging from negative impact, no difference, to positive experience. This is likely due to the complex nature of understanding the sibling experience. We focus on particular elements of the framework and review recent novel literature to help guide future directions for research and practice including the influence of culture, methodological considerations, and wider participatory methods.Summary: the Siblings Embedded System Framework can be used to understand interactive factors that affect sibling adjustment and to develop clinically, educationally and empirically based work that aims to enhance and support sibling adjustment, relationships, and well-being in families of children with autism.<br/
Quantificação da resistência tênsil e da friabilidade de um latossolo vermelho distroférrico sob plantio direto
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