7,287 research outputs found
Flexible arms provide constant force for pressure switch calibration
In-place calibration of a pressure switch is provided by a system of radially oriented flexing arms which, when rotated at a known velocity, convert the centrifugal force of the arms to a linear force along the shaft. The linear force, when applied to a pressure switch diaphragm, can then be calculated
Analytic solutions of the geodesic equation in axially symmetric space-times
The complete sets of analytic solutions of the geodesic equation in
Taub--NUT--(anti-)de Sitter, Kerr--(anti-)de Sitter and also in general
Plebanski--Demianski space--times without acceleration are presented. The
solutions are given in terms of the Kleinian sigma functions.Comment: 4 pages, 4 figures, accepted for publication in EP
Micromagnetic Domain Structures in Cylindrical Nickel Dots
The magnetic domain structures of cylindrical nickel dots (diameters from 40 nm to 1700 nm) with anisotropy parallel to the cylinder axis is predicted by the ratio of the dot diameter to the stripe period of unpatterned films with the same perpendicular anisotropy. The dominant domain structure for a given ratio increases in complexity as the ratio increases. We present evidence for the full micromagnetic domain structure for the simplest cases
Thermal/acoustical aircraft insulation material
Attempts made to improve the acoustical properties of low density Fiberfrax foam, an aircraft insulation material, are reported. Characterizations were also made of the physical and thermal properties. Two methods, optimization of fiber blend composition and modification of the foam fabrication process, were examined as possible means of improving foam acoustics. Flame impingement tests were also made; results show performance was satisfactory
Magnetic Response Versus Lift Height of Thin Ferromagnetic Films
The interaction between a magnetic force microscope (MFM) tip and ferromagnetic films of Ni, Co90Fe10 and Py with in-plane magnetization has been investigated. The measured interaction, due to the magnetizing of the films by the MFM tip field, was determined by the phase shift of the cantilever response. The tip-film separation or lift height dependent phase shift was found to be independent of the saturation magnetization of the ferromagnetic film. The result is identical for all three films and micromagnetic simulations give similar results. The reason is at a given tip-sample separation the tip induced magnetization of the film creates a demagnetization field which is equal in magnitude to the tip field at that separation
Evaluation of 3-P sampling as a midcycle measurement of CFI (Ames Plantation)
The objective of this study was to evaluate 3-P sampling as a midcycle volume estimate of CFI. A two-stage 3-P sampling technique was established for forest lands controlled by The University of Tennessee at Ames Plantation whereby the present fixed area plot CFI system was modified to include a midcycle volume and growth estimate based on 3-P sampling. The two-stage 3-P sampling technique was compared with the present CFI system by evaluating the precision and cost of each method. Using 3-P sampling with volume as a predictor and the same tree volume estimating procedures, 120 trees were selected for remeasurement versus the 2,395 trees required by the present CFI method. The pulpwood volume per acre estimated by 3-P sampling was within 1.11% of that obtained by the present CFI system. Three-P sampling estimated 225.71 cubic feet per acre while 228.23 cubic feet per acre was estimated by CFI. Sawtimber volume per acre estimated by 3-P sampling was within 0.56% of that obtained by the present CFI method. Three-P sampling estimated 4186.90 board feet per acre while 4210.39 board feet per acre was estimated by CFI. The relative standard errors for the 3-P volume per acre were 6.78% for pulpwood and 13.53% for sawtimber; relative standard errors for the CFI volume per acre were 6.91% for pulpwood and 7.67% for sawtimber. Modification of the present CFI system, by adding a basal area factor prism sample (during the first stage sample) at every plot center for measuring all trees one inch in diameter and larger, was recommended to accommodate 3-P sampling for midcycle volume and growth estimation
The Formation of Thin Continuous Films from Isolated Nuclei
Formation of thin continuous films from isolated nuclei and effect of electron beam, residual gases, and surface conditions on film growt
Probability of Causation for Lung Cancer After Exposure to Radon Progeny: A Comparison of Models and Data
The estimates of lung cancer risk due to the exposure to radon decay products are based on different data sets from underground mining and on different mathematical models that are used to fit the data. Diagrams of the excess relative rate per 100 working level months in its dependence on age at exposure and age attained are shown to be a useful tool to elucidate the influence that is due to the choice of the model, and to assess the differences between the data from the major western cohorts and those from the Czech uranium miners. It is seen that the influence of the choice of the model is minor compared to the difference between the data sets. The results are used to derive attributable lifetime risks and probabilities of causation for lung cancer following radon progeny exposures
- …