5,993 research outputs found
Design of the Galileo remote science pointing actuators
This paper describes the two actuators developed for pointing the remote science instruments from the spinning Galileo spacecraft. Details of the key elements are presented together with their design features and developmental difficulties. Four techniques used for power and signal transfer across the actuators' rotating joints are also discussed
Wetting on Lines and Lattices of Cylinders
This paper discusses wetting and capillary condensation transitions on a line
and a rectangular array of cylinders using an interface potential formalism.
For a line of cylinders, there is a capillary condensation transition followed
by complete wetting if the cylinders are sufficiently close together. Both
transitions disappear as the cylinder separation is increased. The dependence
of the wetting phase diagram of a rectangular array of cylinders is discussed
as a function of the chemical potential, substrate--fluid interaction strength
and surface tension.Comment: 17 pages in total: 11 pages of Latex document and 6 pages of figures,
Latex Version 2.09, OUTP-93-40
Forecasting UK Industrial Production Over the Business Cycle
This paper examines the information available through leading indicators for modelling and forecasting the UK quarterly index of production (seasonally adjusted). The emphasis is on one-quarter ahead prediction, especially over the 1990s recession. Linear specifications considered are univariate autoregressive models together with dynamic single indicator and multiple indicator models. Both univariate and leading indicator versions of nonlinear Markov switching specifications are also examined. In the latter case, the transition probabilities are modelled as logistic functions of the leading indicators, allowing the lead times to differ for the expansion to expansion and recession to recession probabilities. Despite general evidence that the term structure of interest rates helps regime classification in the Markov switching models, these models perform relatively poorly in forecasting the 1990s production recession. It is suggested that this poor performance may be due to the nature of that recession, which differed from previous major UK postwar recessions in having no single quarter where industrial production declined substantially. However, a three indicator linear specification does well. The leading indicator variables in this latter model are a short-term interest rate, the stock market dividend yield and the optimism balance from the quarterly survey conducted by the Confederation of British Industry.
Variability of extreme daily precipitation in the United Kingdom. Observed and simulated relationships with the synoptic scale atmospheric circulation
Effect of casing treatment of overall performance of axial-flow transonic fan stage with pressure ratio of 1.75 and tip solidity of 1.5
The effect of a number of casing treatments on the overall performance of a 1.75-pressure-ratio, 423-m/sec-tip-speed fan stage was evaluated. The skewed slot configuration with short-open slots over the midportion of the rotor had a stall margin of 23.5 percent, while the solid casing had a stall margin of 15.0 percent. The skewed slot configuration with long open slots extending ahead of and over portion of rotor displaced the stall line to the lowest flow at all speeds tested. At design speed, the peak efficiency for the long, forward open slots was 1 point less than that for the short midopen slots and 3 points less than that for the solid casing
Effects of tip clearance on overall performance of transonic fan stage with and without casing treatment
The overall performance of a transonic fan stage is presented for various tip clearances, with and without casing treatment. The stage was tested with a solid casing, and with open skewed slots and closed skewed slots in the casing over the rotor blade tips. Four nominal nonrotating rotor blade tip clearances from 0.061 to 0.178 centimeter were used. For all three casings, the pressure ratio and efficiency decreased with increasing tip clearance. The stall margin for a given casing also decreased with increasing clearance. At design speed and a given tip clearance, the highest stall margin was obtained with the open-slot casing, and the lowest stall margin was obtained with the solid casing
Performance of a 1.15-pressure-ratio axial-flow fan stage with a blade tip solidity of 0.5
The overall and blade-element performance of a low-solidity, low-pressure-ratio, low-tip-speed fan stage is presented over the stable operating range at rotative speeds from 90 to 120 percent of design speed. At design speed a stage peak efficiency of 0.836 was obtained at a weight flow of 30.27 kilograms per second and a pressure ratio of 1.111. The pressure ratio was less than design pressure ratio, and the design energy input into the rotor was not achieved. A mismatch of the rotor and stator blade elements resulted due to the lower than design pressure ratio of the rotor
Performance of a transonic fan stage designed for a low meridional velocity ratio
The aerodynamic performance and design parameters of a transonic fan stage are presented. The fan stage was designed for a meridional velocity ratio of 0.8 across the tip of the stage, a pressure ratio of 1.57, a flow of 29.5 kilograms per second, and a tip speed of 426 meters per second. Radial surveys were obtained over the stable operating range from 50 to 100 percent of design speed. The measured, peak efficiency (0.81) of the stage occurred at a pressure ratio of 1.58 and a flow of 28.7 kilograms per second
Rehabilitation of a 49 Year-Old Male Who Underwent a Right Knee Anterior Cruciate Ligament Reconstruction with Moderate to Severe Degenerative Joint Disease of the Left Knee
Background/purpose: Anterior cruciate ligament (ACL) rupture is reported to be one of the most common and most serious injuries among physically active individuals, There are a multitude of articles addressing rehabilitation following ACL reconstruction, but there is no clear best method\u27 identified in the evidence, Subjects with a combination of ACL rupture and degenerative joint disease are less frequent in occurrence, and also lack evidence to identify the most appropriate rehabilitation method.
Description: This case study provides the details of the first 8 weeks of rehabilitation for a 49 year old male subject who underwent anterior cruciate ligament reconstruction of one knee with moderate to severe degenerative joint disease of the contralateral knee.
Outcome: The subject was able to recover full range of motion of the anterior cruciate ligament reconstructed knee and was able to gain 10 degrees of flexion in the knee with degenerative joint disease within 4 weeks of right knee ACL reconstructive surgery, The subject was able to perform all ADL activities to include stairs without discomfort at 6 weeks post-op, Thigh girth at 15 cm above the medial joint line was equal at 8 weeks post-op, KT-1000 score indicated less than I mm difference at 8 weeks postop.
Discussion: The rehabilitation program for this patients\u27 ACL reconstructed knee followed a traditional, evidence based approach with modifications for patients age and presence of degenerative joint disease in the contralateral knee. A combination of closed chain exercise, neuromuscular re-education and open chain exercises were used with this patient. The short-term results appear to be encouraging related to range of motion and muscle function. However, in this patients\u27 case-as well as for other patients undergoing this procedure, the long-term (5 -10 years) outcome is most important
SAM 2 data user's guide
This document is intended to serve as a guide to the use of the data products from the Stratospheric Aerosol Measurement (SAM) 2 experiment for scientific investigations of polar stratospheric aerosols. Included is a detailed description of the Beta and Aerosol Number Density Archive Tape (BANAT), which is the SAM 2 data product containing the aerosol extinction data available for these investigations. Also included are brief descriptions of the instrument operation, data collection, processing and validation, and some of the scientific analyses conducted to date
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