Further evidence to change the medical classification system of the National Wheelchair Basketball Association

A number of researchers have long questioned systems used for classifying athletes with disabilities. Wheelchair basketball players have gained much attention from researchers. Despite this, no change to the NWBA classification system has been made since it was first adopted in 1984. This study investigated the NWBA classification system. At two summer basketball camps, 46 players were tested to assess player sprint performance and stratification under the NWBA medical classification system. The group consisted of Class 1, 2, and 3 players. Electronic timing gates were used to collect 20 meter sprint-times. Results indicate that Class 1 players were significantly slower compared to Class 2 and 3 players (p < .05) with no difference between Class 2 and 3. The results of this study support a change to this system

Theoretical, numerical, and experimental investigation of pressure rise due to deflagration in confined spaces

Estimating pressure rise due to deflagration in a fully or partially confined space is of practical importance in safety design of a petrochemical plant. Herein, we have developed a new theoretical model to predict the pressure rise due to deflagration in both fully and partially confined spaces. First, the theoretical model was compared and validated against experimental data from the closed-space experiments with hydrogen, methane, propane, and ethane. The theory predicted accurate pressure rises near the stoichiometric regime for all fuel types; outside the stoichiometric regime, especially, for rich mixtures of hydrocarbons with air, the theory over-predicted pressure rise since it does not account for soot formation and the associated energy losses by radiation. Experimental investigation of propane and hydrogen deflagration was conducted in a partially confined space and the theory-based predictions agreed with the data up to 5%. Parametric numerical study was performed to investigate the effect of the initial pressure and temperature of gaseous fuels on pressure rise. (C) 2017 Elsevier Masson SAS. All rights reserved