William C. Alexander

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This study investigated the potential value of specific cellular responses to acute and chronic exercise as indices of physical fitness. Muscle enzymatic and hemolytic responses following a progressive cycle-ergometer test to maximal aerobic capacity were studied in 12 women and 12 men, aged 27 to 55 yr, who had been previously assigned to "high" and "low"(More)
In this paper, a multiport high-frequency ac link inverter is proposed as the power electronic interface between the photovoltaic (PV) modules, battery energy storage system, and three-phase ac load. In this inverter, a single-stage power conversion unit fulfills all the system requirements, i.e., inverting dc voltage to proper ac, stepping up or down the(More)
 Abstract— In this paper a high frequency ac link photovoltaic (PV) inverter is proposed. The proposed inverter overcomes most of the problems associated with the currently available PV inverters. In this inverter a single stage power conversion unit fulfills all the systems requirements; i.e., inverting dc voltage to proper ac, stepping up or down the(More)
In this paper, the soft-switching ac-link ac-ac buckboost converter will be studied in more detail. This single-stage converter, which is in essence an extension of the dc-dc buck-boost converter, can be an excellent alternative to dc-link converters. Being a buck-boost converter, this converter is capable of both stepping-up and stepping-down the voltage.(More)
The third in a series of Spacelab Mission Development tests was conducted at the Johnson (correction of Johnston) Space Center as a part of the development of Life Sciences experiments for the Space Shuttle era. The latest test was a joint effort of the Ames Research and Johnson Space Centers and utilized animals and men for study. The basic objective of(More)