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31.
Roberts L 《Endeavour》2000,24(2):55-58
The history of the steam engine is generally linked to that of the Industrial Revolution. This article seeks to uncouple this seemingly necessary link by examining other contexts in which the steam engine was introduced and developed.  相似文献   
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The roles and functions of 52 school psychologists from Iowa and Tennessee were examined. A multivariate analysis of variance (MANOVA) was used to test differences between reported time spent on prereferral, assessment, intervention, consultation, and curriculum-based assessment. Significant differences were found for the time spent in all areas. A second one-way MANOVA was used to test the differences between the two groups in reported actual time spent and desired time spent. A significant difference was found for consultation. A third MANOVA was utilized to test the differences between the two groups' desired time spent on the five variables. A significant difference was found for curriculum-based assessment. The results suggest that school psychologists in Tennessee and Iowa occupy different roles. School psychologists in Tennessee reported spending the majority of their time on assessment activities, whereas the Iowa sample balances their time between the five functions. The Iowa role exemplifies alternative functions for school psychologists. The Tennessee role is oriented more toward the refer, test, place model.  相似文献   
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The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders’ bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14)?=?6.448; p?=?.010) and peak torque (F(2,14)?=?4.777; p?=?.026), but no significant difference was found for time to peak power (F(2,14)?=?0.200; p?=?.821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658?±?221?W, compared to 1436?±?129?W and 1380?±?56?W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in ?0.01?s and a 45/16 in 0.22?s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.  相似文献   
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