9,556 research outputs found
Cracks in glass electrical connector headers removed by dry blasting with fine abrasive
Cracking that causes pressure leakage in glass connector headers can be alleviated by manipulating the pin bridgewire connectors. This initiates the surface and meniscus cracks. Dry blasting the header surface with a fine abrasive then removes the cracks
Transpiration cooled turbine blade manufactured from wires Patent
Transpiration cooled turbine blade made from metallic or ceramic wire
Low-speed wind tunnel investigation of the lateral-directional characterisitcs of a large-scale variable wing-sweep fighter model in the high-lift configuration
The low-speed characteristics of a large-scale model of the F-14A aircraft were studied in tests conducted in the Ames Research Center 40- by 80-Foot Wind Tunnel. The primary purpose of the present tests was the determination of lateral-directional stability levels and control effectiveness of the aircraft in its high-lift configuration. Tests were conducted at wing angles of attack between minus 2 deg and 30 deg and with sideslip angles between minus 12 deg and 12 deg. Data were taken at a Reynolds number of 8.0 million based on a wing mean aerodynamic chord of 2.24 m (7.36 ft). The model configuration was changed as required to show the effects of direct lift control (spoilers) at yaw, yaw angle with speed brake deflected, and various amounts and combinations of roll control
Three level atom optics in dipole traps and waveguides
An analogy is explored between a setup of three atomic traps coupled via
tunneling and an internal atomic three-level system interacting with two laser
fields. Within this scenario we describe a STIRAP like process which allows to
move an atom between the ground states of two trapping potentials and analyze
its robustness. This analogy is extended to other robust and coherent transport
schemes and to systems of more than a single atom. Finally it is applied to
manipulate external degrees of freedom of atomic wave packets propagating in
waveguides.Comment: 14 pages, 6 figures; submitted to special issue 'Quantum Control of
Light and Matter' of Optics Communication
Hermetically sealed motion transmitter
Transmitter allows transmission of rotational or single planar arc motion through hermetically sealed chamber without use of dynamic seals or complex mechanisms. Device may interest pressure vessel designers and those who need to isolate equipment from a hostile environment
Limb compression does not alter the forces generated during the vertical jump
PURPOSE: The purpose of this study was to identify potential differences in impulse force generated during the vertical jump while wearing commercially available compression shorts as compared to non-compressive, loose fitting gym shorts.
HYPOTHESIS: Leg muscle compression will produce no significant difference in muscle performance variables generated during a standard vertical jump test when compared to no compression.
METHODS: Twenty five physically active males between the ages of 18 and 30 were recruited for this study. Each subject was asked to wear 4 types of shorts: non-compressive gym shorts (representing a control), regular fitting compression shorts (by manufacturer standard), undersized compression shorts (one size smaller than manufacturer standard), and oversized compression shorts (one size larger than manufacturer standard). The subjects were familiarized with the testing procedures and then completed the three randomized conditions on the same day. The performance tests consisted of 3 sets of 10 countermovement vertical jumps performed upon a force platform. The dependent measures included: velocity at takeoff (Vto; m·s), fatigability across jumps (Vf ; m·s) and surface electromyography (EMG; volts).The maximal impulse generated was taken from the highest curve out 4 of the 10 jumps and average power was determined across the 10 jumps in each condition. The individual compression values were then determined in each condition for each subject with the use of a custom made compression quantification device. Results: There were no significant differences (P>.05) in Vto, Vf, and EMG across compression levels. Conclusions: The compression garments produce no significant change in the forces generated during the vertical jump.Submitted to the faculty of the University Graduate School in partial fulfillment of the requirements for the degree Master of Sciences in the School of Heath, Physical Education, and Recreation, Department of Kinesiology, Indiana Universit
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