Performance Technologies, Incorporated

About: Performance Technologies, Incorporated is a based out in . It is known for research contribution in the topics: Quantum turbulence & Bose–Einstein condensate. The organization has 66 authors who have published 76 publications receiving 2271 citations.

The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3

Abstract: The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. The goal of CM3 is to address emerging issues in climate change, including aerosol–cloud interactions, chemistry–climate interactions, and coupling between the troposphere and stratosphere. The model is also designed to serve as the physical system component of earth system models and models for decadal prediction in the near-term future—for example, through improved simulations in tropical land precipitation relative to earlier-generation GFDL models. This paper describes the dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component (AM3) of this model. Relative to GFDL AM2, AM3 includes new treatments of deep and shallow cumulus convection, cloud droplet activation by aerosols, subgrid variability of stratiform vertical velocities for droplet activation, and atmospheric chemistry driven by emiss...

Hitting a Baseball: A Biomechanical Description

Abstract: A tremendous amount of time and energy has been dedicated to the development of conditioning programs, mechanics drills, and rehabilitation protocols for the throwing athlete. In comparison, a significantly smaller amount has been spent on the needs of the hitting athlete. Before these needs can be addressed, an understanding of mechanics and the demands placed on the body during the swing must be developed. This study uses three-dimensional kinematic and kinetic data to define and quantify biomechanics during the baseball swing. The results show that a hitter starts the swing with a weight shih toward the rear foot and the generation of trunk coil. As the hitter strides forward, force applied by the front foot equal to 123% of body weight promotes segment acceleration around the axis of the trunk. The hip segment rotates to a maximum speed of 714° /sec followed by a maximum shoulder segment velocity of 937°/sec. The product of this kinetic link is a maximum linear bat velocity of 31 m/sec. By quantifying...

Motion analysis system employing various operating modes

Abstract: A motion analysis system and apparatus incorporates markers which are secured at various joints of the subject's body as well as pressure sensitive shoes or insoles which are worn by the subject. The subject is caused to perform motion such as walking or running. While performing this motion, the subject is televised by means of two video cameras. The video signal from the cameras is stored by means of video recorders and then processed on a frame-to-frame basis to provide digitized data. The pressure sensitive insoles provide signals which are processed according to analog to digital conversion techniques whereby a display is also provided which indicates the pressure applied to the subject's foot while performing. The remaining data as supplied by the first and second video cameras and which is digitized is then further processed to present various displays showing the gait, the angular position of the various joints of the patient and various other information indicative of the particular walking characteristics of the subject. The data thus produced and processed by the system enables a practitioner to judge the persons's walking gait as compared to a normal user.