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ABSTRACTThe preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many studies have been carried out on the best way to control hygrothermal conditions. In old buildings located in maritime temperate climate zones (such as Portugal) with strong thermal inertia, and which have low ventilation rate (relative to the volume and number of visitors), daily and seasonal hygroscopic inertia may help to assure the maintenance of RH stabilization conditions. The use of expensive active systems may be minimized through the passive behaviour of internal finishing building materials. This work presents the results of an experimental laboratory study conducted in a flow chamber to demonstrate the enormous potential of hygroscopic materials in stabilizing interior relative humidity. Based in these results and in-situ monitoring in a museum housed in a building, located in Porto, with a typical construction of the 1950s (granite masonry and reinforced concrete slabs), a numerical analysis was done to quantify the influence of hygroscopic materials in stabilizing the interior relative humidity. 相似文献
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Tyler J. Stidwill Rene Albert Turcotte Phil Dixon David J. Pearsall 《Sports Engineering》2009,12(2):63-68
The purpose of this study was to develop a portable force measurement system for ice hockey skating. The system consisted
of three strain gauge pairs affixed to an ice hockey skate’s blade holder with wire leads connected to a microprocessor controlled
data acquisition device carried in a backpack worn by the skater. The configuration of the strain gauges simultaneously determined
the vertical and medial–lateral force components experienced by the blade holder with a resolution accuracy of 1.9 N and a
coefficient of variation of 9.2%. On-ice testing of this system with subjects performing forward start, acceleration, and
constant velocity skating permitted unencumbered, natural movement and demonstrated clear, unambiguous signal responses, high
trial-to-trial repeatability, and easy data retrieval. The practicality and accuracy of this testing approach have many applications,
such as a quantitative tool for skating force assessment to aid athletes and coaches, as well as providing the means to examine
other skill-specific dynamics. 相似文献
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V. J. Hinton D. C. De Vivo R. Fee E. Goldstein Y. Stern 《Learning disabilities research & practice》2004,19(3):146-154
Duchenne Muscular Dystrophy (DMD) is a neurogenetic developmental disorder that presents with progressive muscular weakness. It is caused by a mutation in a gene that results in the absence of specific products that normally localize to muscle cells and the central nervous system (CNS). The majority of affected individuals have IQs within the normal range, generally with lower verbal than performance IQ scores. Prior work has demonstrated selective deficits on tests of verbal span and immediate memory. For the current study, 26 boys with DMD (and normal intellectual function) and their unaffected siblings were evaluated. Paired comparisons demonstrated that the children with DMD had significantly poorer academic achievement scores than their siblings, even though their vocabulary levels and home and educational environments were comparable. Children with DMD also had more behavioral concerns, physical disabilities, and poorer verbal memory spans. Linear regression indicated that behavioral concerns, executive function, and physical disability did not contribute substantially to academic performance, whereas performance on verbal span did. DMD presents with a selective developmental aberration in verbal span that has wide‐ranging consequences on learning skills. 相似文献
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