836 research outputs found
Thermal experiences of older people during hot conditions in Adelaide
Theme: Fifty years later: Revisiting the role of architectural science in design and practiceThis study examined the thermal experiences of older people during extreme heat and summer more broadly. A longitudinal field study of thermal comfort and thermal acceptability of conditions during summer 2015-16 was conducted as part of a larger project into the overall thermal comfort of older people in Adelaide, South Australia. The experiences and preferences of the participants were arranged into 3 categories: acceptable thermal sensation votes, warm and hot thermal sensation votes and votes recorded on extreme heat days when the maximum outdoor temperature was 35º Celsius or above during the study period. In each category, participants reported sensations of ‘warm’ and ‘hot’ within the acceptable range of operative temperature and humidity suggested by ASHRAE Standard 55. Participants also expressed a desire to feel cooler within this acceptable range, and described conditions within this range as ‘thermally unacceptable’. These results show that older people may be experiencing thermal conditions differently to younger people. Specifically, it appears that these articipants have a desire for cooler temperatures than predicted by ASHRAE Standard 55. The study poses a series of challenges for future research to ensure comfortable and healthy homes for ageing Australians.Rachel Bills, Veronica Soebarto and Terence Williamso
Cold comfort: thermal sensation in people over 65 and the consequences for an ageing population
In Australia the preference of most of the ageing population is to age in place. It is therefore necessary that the thermal environment in homes provides comfort for its occupants to promote healthy ageing. Houses that are too hot or too cold are not only unpleasant to live in but may pose a health risk, especially amongst a vulnerable population.
The study reported in this paper is part of larger research into the thermal practices of people over 65 in Adelaide, South Australia. The aim of this study was to examine the thermal comfort of people over the age of 65 during the coldest winter month as well as during a record breaking hot summer month in 2015. A longitudinal comfort study of both living areas and bedrooms was conducted in 10 South Australian households during these periods. The comfort vote survey included the ASHRAE 7-point sensation scale and the McIntyre 3-point preference scale.
Preliminary data indicate these occupants find thermal conditions comfortable at cooler temperatures than predicted by the ASHRAE thermal comfort standard, with significant numbers of neutral votes occurring at lower temperatures than expected. During the warmer conditions however, the majority of neutral votes were in the region predicted by the model.
This research presents a unique perspective of household thermal comfort in older people during two extremes in temperature conditions in Adelaide. This may have implications for healthy housing design for an ageing population.Rachel Bill
Comparison of Simulator Wear Measured by Gravimetric vs Optical Surface Methods for Two Million Cycles
Understanding wear mechanisms are key for better implants
Critical to the success of the simulation
Small amount of metal wear can have catastrophic effects in the patient such as heavy metal poisoning or deterioration of the bone/implant interface leading to implant failure
Difficult to measure in heavy hard-on-hard implants (metal-on-metal or ceramic-on-ceramic)
May have only fractions of a milligram of wear on a 200 g component
At the limit of detection of even high-end balances when the component is 200 g and the change in weight is on the order of 0.000 1 grams
Here we compare the standard gravimetric wear estimate with
A non-contact 3D optical profiling method at each weighing stop
A coordinate measuring machine (CMM) at the beginning and end of the ru
A lexical transducer for North Slope Iñupiaq
Thesis (M.A.) University of Alaska Fairbanks, 2011This thesis describes the creation and evaluation of software designed to analyze and generate North Slope Iñupiaq words. Given a complete lñupiaq word as input, it attempts to identify the word's stem and suffixes, including the grammatical category and any inflectional information contained in the word. Given a stem and list of suffixes as input, it attempts to produce the corresponding Iñupiaq word, applying phonological processes as necessary. Innovations in the implementation of this software include Iñupiaq-specific formats for specifying lexical data, including a table-based format for specifying inflectional suffixes in paradigms; a treatment of phonologically-conditioned irregular allomorphy which leverages the pattern-recognition capabilities of the xfst programming language; and an idiom for composing morphographemic rules together in xfst which captures the state of the software each time a new rule is added, maximizing feedback during software compilation and facilitating troubleshooting. In testing, the software recognized 81.2% of all word tokens (78.3% of unique word types) and guessed at the morphology of an additional 16.8% of tokens (19.4% of types). Analyses of recognized words were largely accurate; a heuristic for identifying accurate parses is proposed. Most guesses were at least partly inaccurate. Improvements and applications are proposed.National Science Foundation (Award 0534217
An Inversion of Gravity and Topography for Mantle and Crustal Structure on Mars
Analysis of the gravity and topography of Mars presently provides our primary quantitative constraints on the internal structure of Mars. We present an inversion of the long-wavelength (harmonic degree less than or equal to 10) gravity and topography of Mars for lateral variations of mantle temperature and crustal thickness. Our formulation incorporates both viscous mantle flow (which most prior studies have neglected) and isostatically compensated density anomalies in the crust and lithosphere. Our nominal model has a 150-km-thick high-viscosity surface layer over an isoviscous mantle, with a core radius of 1840 km. It predicts lateral temperature variations of up to a few hundred degrees Kelvin relative to the mean mantle temperature, with high temperature under Tharsis and to a lesser extent under Elysium and cool temperatures elsewhere. Surprisingly, the model predicts crustal thinning beneath Tharsis. If correct, this implies that thinning of the crust by mantle shear stresses dominates over thickening of the crust by volcanism. The major impact basins (Hellas, Argyre, Isidis, Chryse, and Utopia) are regions of crustal thinning, as expected. Utopia is also predicted to be a region of hot mantle, which is hard to reconcile with the surface geology. An alternative model for Utopia treats it as a mascon basin. The Utopia gravity anomaly is consistent with the presence of a 1.2 to 1.6 km thick layer of uncompensated basalt, in good agreement with geologic arguments about the amount of volcanic fill in this area. The mantle thermal structure is the dominant contributor to the observed geoid in our inversion. The mantle also dominates the topography at the longest wavelengths, but shorter wavelengths (harmonic degrees greater than or equal to 4) are dominated by the crustal structure. Because of the uncertainty about the appropriate numerical values for some of the model's input parameters, we have examined the sensitivity of the model results to the planetary structural model (core radius and core and mantle densities), the mantle's viscosity stratification, and the mean crustal thickness. The model results are insensitive to the specific thickness or viscosity contrast of the high-viscosity surface layer and to the mean crustal thickness in the range 25 to 100 km. Models with a large core radius or with an upper mantle low-viscosity zone require implausibly large lateral variations in mantle temperature
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Using Geological Implications of a Physical Libration to Constrain Enceladus' Libration State
Observations of Enceladus' south pole revealed large rifts in the crust, called "tiger stripes", which exhibit higher temperatures than the surrounding terrain and are likely sources of observed eruptions. Tidal stress may periodically open the tiger stripe rifts, controlling the timing and location of eruptions. Moreover, shear motion along rifts may produce the heat to drive eruptions
Geological Implications of a Physical Libration on Enceladus
Given the non-spherical shape of Enceladus (Thomas et al., 2007), the satellite will experience gravitational torques that will cause it to physically librate as it orbits Saturn. Physical libration would produce a diurnal oscillation in the longitude of Enceladus tidal bulge which, could have a profound effect on the diurnal stresses experienced by the surface of the satellite. Although Cassini ISS has placed an observational upper limit on Enceladus libration amplitude of F < 1.5deg (Porco et al., 2006), smaller amplitudes can still have geologically significant consequences. Here we present the first detailed description of how physical libration affects tidal stresses and how those stresses then might affect geological processes including crack formation and propagation, south polar eruption activity, and tidal heating. Our goal is to provide a framework for testing the hypothesis that geologic features on Enceladus are produced by tidal stresses from diurnal physical and optical librations of the satellite
The reliability of a semi-quantitative scoring method for taper corrosion and fretting, and its usefulness for predicting the volume of material loss
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