14,420 research outputs found
Urban Low-Income African American Men, HIV/AIDS, and Gender Identity
This article explores the sociocultural meanings attached to sexual behaviors and conceptions of masculinity among low-income African-American males. The author argues that HIV/AIDS prevention programs should incorporate strategies to help this population achieve a more healthy gender identity
"Ultimate state" of two-dimensional Rayleigh-Benard convection between free-slip fixed temperature boundaries
Rigorous upper limits on the vertical heat transport in two dimensional
Rayleigh-Benard convection between stress-free isothermal boundaries are
derived from the Boussinesq approximation of the Navier-Stokes equations. The
Nusselt number Nu is bounded in terms of the Rayleigh number Ra according to
uniformly in the Prandtl number Pr. This Nusselt
number scaling challenges some theoretical arguments regarding the asymptotic
high Rayleigh number heat transport by turbulent convection.Comment: 4 page
Polarization perception device
A polarization perception device comprises a base and a polarizing filter having opposite broad sides and a centerline perpendicular thereto. The filter is mounted on the base for relative rotation and with a major portion of the area of the filter substantially unobstructed on either side. A motor on the base automatically moves the filter angularly about its centerline at a speed slow enough to permit changes in light transmission by virtue of such movement to be perceived as light-dark pulses by a human observer, but fast enough so that the light phase of each such pulse occurs prior to fading of the light phase image of the preceding pulse from the observer's retina. In addition to an observer viewing a scene in real time through the filter while it is so angularly moved, or instead of such observation, the scene can be photographed, filmed or taped by a camera whose lens is positioned behind the filter
Aeronautical fuel conservation possibilities for advanced subsonic transports
The anticipated growth of air transportation is in danger of being constrained by increased prices and insecure sources of petroleum-based fuel. Fuel-conservation possibilities attainable through the application of advances in aeronautical technology to aircraft design are identified with the intent of stimulating NASA R and T and systems-study activities in the various disciplinary areas. The material includes drag reduction; weight reduction; increased efficiency of main and auxiliary power systems; unconventional air transport of cargo; and operational changes
Manned simulations of the SRMS in SIMFAC
SIMFAC is a general purpose real-time simulation facility currently configured with an Orbiter-like Crew Compartment and a Displays and Controls (D and C) Subsystem to support the engineering developments of the Space Shuttle Remote Manipulator (SRMS). The simulation consists of a software model of the anthropomorphic SRMS manipulator arm including the characteristics of its control system and joint drive modules. The following are discussed: (1) simulation and scene generation subsystems; (2) the SRMS task in SIMFAC; (3) operator tactics and options; (4) workload; (5) operator errors and sources; (6) areas for further work; and (7) general observations
Ethics in Correctional Education
Ethics has been researched in corrections and education separately; however, there has been limited research related to the dialogue in correctional education. This paper defines the state of ethics in correctional education, identify the function of ethical dilemmas for correctional educators, and suggest a method for resolving dilemmas
The Economic Value of Marine Recreational Fishing: Analysis of the MRFSS 1998 Pacific Add-on
Marine Recreational Fishing Statistics Survey (MRFSS) economic add-on data has been collected since 1994. The data are comprised of two geographically identical datasets for the Southeast region (1997, 2000), five identical datasets for the Northeast region (1994, 1996, 1997, 1999, 2000), and one dataset for the Pacific region (1998). Measures of the economic value of fishing sites and harvest have been derived from demand models estimated with data from the Northeast and the Southeast regions. In this paper we present a demand model estimated for the Pacific region (i.e., west coast). For consistency, the model is based on the 1994 and 1997 studies. Measures of the economic value of fishing sites and harvest are developed. We demonstrate how the model can be used for fisheries management decisions.
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