12,066 research outputs found
Kinesimetric method and apparatus
Apparatus and method for the determination of functional capability of bodies are disclosed. Reach as well as velocity, acceleration and force generation at various positions may be determined for a body by a three dimensional kinesimeter equipped with an ergometer. A general data package indicative of performance potential of a subject body or collection of bodies is provided for interfacing with data characteristics of various environments
Fast food restaurant locations : could they be \u27supersizing\u27 local communities?
This review examines the current state of knowledge related to the location of fast food restaurants. Previous studies have revealed some communities are more exposed to fast food restaurants. However, the influence of increased exposure to fast food on dietary behaviours remains unresolved. This is identified as an area of priority for future research.<br /
Method and apparatus for simulating gravitational forces on a living organism
A method and apparatus for simulating gravitational forces on a living organism wherein a series of negative pressures are externally applied to successive length-wise sections of a lower limb of the organism. The pressures decreasing progressively with distance of said limb sections from the heart of the organism. A casing defines a chamber adapted to contain the limb of the organism and is rigidified to resist collapse upon the application of negative pressures to the interior of the chamber. Seals extend inwardly from the casing for effective engagement with the limb of the organism and, in cooperation with the limb, subdivide the chamber into a plurality of compartments each in negative pressure communicating relation with the limb
The climatological relationships between wind and solar energy supply in Britain
We use reanalysis data to investigate the daily co-variability of wind and
solar irradiance in Britain, and its implications for renewable energy supply
balancing. The joint distribution of daily-mean wind speeds and irradiances
shows that irradiance has a much stronger seasonal cycle than wind, due to the
rotational tilt of the Earth. Irradiance is weakly anticorrelated with wind
speed throughout the year (): there is a weak
tendency for windy days to be cloudier. This is particularly true in
Atlantic-facing regions (western Scotland, south-west England). The east coast
of Britain has the weakest anticorrelation, particularly in winter, primarily
associated with a relative increase in the frequency of clear-but-windy days.
We also consider the variability in total power output from onshore wind
turbines and solar photovoltaic panels. In all months, daily variability in
total power is always reduced by incorporating solar capacity. The scenario
with the least seasonal variability is approximately 70%-solar to 30%-wind.
This work emphasises the importance of considering the full distribution of
daily behaviour rather than relying on long-term average relationships or
correlations. In particular, the anticorrelation between wind and solar power
in Britain cannot solely be relied upon to produce a well-balanced energy
supply.Comment: 19 pages, 19 figures, accepted for publication in Renewable Energy.
Text updated to match accepted version (one footnote added, some references
corrected
A method of isolating treadmill shock and vibration on spacecraft
A major problem is currently felt to exist in the implementation of materials processing on a spacecraft. Crystal growers place requirements of one micro-g or less on the vehicle. Simple math produces startling figures for such a restriction e.g., for each ton of vehicle mass with 10(-6) g acceleration limit; Perturbing Force limit, F = .002 lb. For each 10(5) lbs F = 0.1 lb. For each 10(6) lbs F = 1.0 lb. Forces generated by normal human movement on spacecraft of 5x10(5) pounds weight are on an order-of-magnitude greater than allowed by this specification and forces generated by locomotion on a treadmill are more than two orders-of-magnitude greater. Other exercises and normal onboard functions generate forces in between. To accommodate many essential functions it is obvious that even on a vehicle as large as Space Station, a reduction of more than two orders of magnitude in force is required. Commonly used passive shock and vibration isolation devices are complex, heavy, and also would have difficulty meeting the requirements. However, by a new arrangement, adequate isolation can be obtained. Isolation of the treadmill will be treated since it is considered the most significant disturbance at this time
A computer program incorporating fatigue and fracture criteria in the preliminary design of transport aircraft: An evaluation
The APAS program a multistation structural synthesis procedure developed to evaluate material, geometry, and configuration with various design criteria usually considered for the primary structure of transport aircraft is described and evaluated. Recommendations to improve accuracy and extend the capabilities of the APAS program are given. Flow diagrams are included
Using the Twentieth Century Reanalysis to assess climate variability for the European wind industry
We characterise the long-term variability of European near-surface wind
speeds using 142 years of data from the Twentieth Century Reanalysis (20CR),
and consider the potential of such long-baseline climate data sets for wind
energy applications. The low resolution of the 20CR would severely restrict its
use on its own for wind farm site-screening. We therefore perform a simple
statistical calibration to link it to the higher-resolution ERA-Interim data
set (ERAI), such that the adjusted 20CR data has the same wind speed
distribution at each location as ERAI during their common period. Using this
corrected 20CR data set, wind speeds and variability are characterised in terms
of the long-term mean, standard deviation, and corresponding trends. Many
regions of interest show extremely weak trends on century timescales, but
contain large multidecadal variability. Since reanalyses such as ERAI are often
used to provide the background climatology for wind farm site assessments, but
contain only a few decades of data, our results can be used as a way of
incorporating decadal-scale wind climate variability into such studies,
allowing investment risks for wind farms to be reduced.Comment: 18 pages, plus 4 page supplementary information included here as
Appendix D. This is the authors' corrected version, matching the content of
the version accepted by Theoretical and Applied Climatolog
Comparison of NASTRAN and MITAS nonlinear thermal analyses of a convectively cooled structure
Comparative steady state nonlinear thermal analyses of a scramjet fuel injection strut are presented. The analyses were performed using the NASTRAN finite element program and MITAS, a lumped-parameter thermal analyzer. The strut is subjected to aerodynamic heating on two sides and is internally cooled by hydrogen flowing from internal manifolds through heat exchangers bonded to the primary structure. Based on coolant temperatures determined by MITAS, NASTRAN predicted temperature distributions throughout the strut which were in close agreement with similar MITAS predictions
Hole cutter
An adjustable hole cutter is described for use in forming circular openings in workpieces. The hole cutter is characterized by a mount of a substantially planar configuration, positionable into a plane paralleling the working plane of a selected workpiece. It also contains a shaft for imparting rotary motion to the mount about an axis of rotation normally related to the working plane, a plurality of stabilizing struts for resiliently supporting the mount in parallelism with the working plane as rotary motion is imparted thereto, a drill bit for drilling a pilot hole concentric with the axis of rotation, and an elongated cutting tool adjustably seated within a radially extended slot
Integrated thermal-structural analysis of large space structures
Optimum performance of large space antennas requires very fine control of the shape of the antenna surface since the shape affects both frequency control and pointing accuracy. A significant factor affecting the antenna shape is the temperature of the structure and the resulting deformation. To accurately predict the temperature of the structure, it is necessary first to accurately predict thermal loads. As the structure orbits the Earth, the thermal loads change constantly so that the thermal-structural response varies continuously throughout the orbit. The results from recent applications of integrated finite element methodology to heat load determination and thermal-structural analysis of large space structures are given. Four areas are concentrated on: (1) the characteristics of the integrated finite element methodology, (2) fundamentals of orbital heat load calculation, (3) description and comparison of some radiation finite elements, and (4) application of the integrated finite-element approach to the thermal-structural analysis of an orbiting truss structure
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