968 research outputs found

    Design knowledge capture for the space station

    Get PDF
    The benefits of design knowledge availability are identifiable and pervasive. The implementation of design knowledge capture and storage using current technology increases the probability for success, while providing for a degree of access compatibility with future applications. The space station design definition should be expanded to include design knowledge. Design knowledge should be captured. A critical timing relationship exists between the space station development program, and the implementation of this project

    An approach to design knowledge capture for the space station

    Get PDF
    The design of NASA's space station has begun. During the design cycle, and after activation of the space station, the reoccurring need will exist to access not only designs, but also deeper knowledge about the designs, which is only hinted in the design definition. Areas benefiting from this knowledge include training, fault management, and onboard automation. NASA's Artificial Intelligence Office at Johnson Space Center and The MITRE Corporation have conceptualized an approach for capture and storage of design knowledge

    Off-design correlation for losses due to part-span dampers on transonic rotors

    Get PDF
    Experimental data from 10 transonic fan rotors were used to correlate losses created by part-span dampers located near the midchord position on the rotor blades. The design tip speed of these rotors varied from 419 to 425 m/sec, and the design pressure ratio varied from 1.6 to 2.0. Additional loss caused by the dampers for operating conditions between 50 and 100 percent of design speed were correlated with relevant aerodynamic and geometric parameters. The resulting correlation predicts the variation of total-pressure-loss coefficient in the damper region to a good approximation

    Poverty and Elimination of Urban Health Disparities Challenge and Opportunity

    Get PDF
    The aim of this article is to examine the intersection of race and poverty, two critical factors fueling persistent racial and ethnic health disparities among urban populations. From the morass of social determinants that shape the health of racial and ethnic communities in our urban centers, we will offer promising practices and potential solutions to eliminating racial and ethnic health disparities

    The National Negro Health Week, 1915 to 1951: A Descriptive Account

    Get PDF
    In 1914, Booker T. Washington, founder of Tuskegee Institute, viewed the poor health status of black Americans as an obstacle to economic progress and issued a call for "the Negro people... to join in a movement which shall be known as Health Improvement Week" (Patterson, 1939). Health Improvement Week evolved into the National Negro Health Week, observed annually for 35 years. This article provides an overview of the structure and activities of the National Negro Health Week and suggests implications for public health in the black community today

    Soil-structure interaction during the San Fernando earthquake

    Get PDF
    Accelerograms obtained at two sites during the San Fernando earthquake of 1971 were analyzed to investigate the role of soil-structure interaction, using techniques developed by Bielak and others. Analysis of the data from the site of the Hollywood Storage Building, for which data from the Arvin-Tehachapi earthquake of 1952 are also available, showed evidence of soil-structure interaction in the way the transfer functions between parking lot and basement motion decayed with increasing frequency in the two lateral directions. It is concluded also that interaction probably had a small effect on the response near the EW fundamental frequency during the San Fernando earthquake. Although theoretical and experimentally determined transfer functions are broadly similar, they do not agree in detail. The lack of good agreement for reasonable choices of the parameters of the theoretical model indicates a need for some modifications of the theory or its application, and a need for more measurements at the site. A similar analysis showed no clear evidence of soil-structure interaction for the Millikan Library and Athanaeum buildings on the campus of the California Institute of Technology. If soil-structure interaction caused the major differences measured in the base motions of these two buildings, it is of a more complex form than that considered by present theories

    The Tuskegee Syphilis Study, 1932 to 1972: Implications for HIV Education and AIDS Risk Education Programs in the Black Community

    Get PDF
    The Tuskegee study of untreated syphilis in the Negro male is the longest nontherapeutic experiment on human beings in medical history. The strategies used to recruit and retain participants were quite similar to those being advocated for HIV/AIDS preention programs today. Almost 60 years after the study began, there remains a trail of distrust and suspicion that hampers HIV education efforts in Black communities. The AIDS epidemic has exposed the Tuskegee study as a histotical marker for legitimate discontent of Blacks with the public health system. The belief that AIDS is a form of genocide is rooted in a social context in which Black Americans, faced with persistent inequality, believe in conspiracy theories about Whites against Blacks. These theories range from the belief that the government promotes drug abuse in Black communities to the belief that HIV is a manmade weapon of racial warfare. An open and honest discussion of the Tuskegee Syphilis Study can facilitate the process of rebuilding trust between the Black community and public health authorities. This dialogue can contribute to the development of HIV education programs that are scientifically sound, culturally sensitive, and ethnically acceptable

    Light on the Shadow of the Syphilis Study at Tuskegee

    Get PDF
    In the 1940s, with the disclosure that Nazi doctors had conducted experiments on humans, the term research crime appeared for the first time. Most Americans believed such abuses could never happen here. On a hot day in July 1972, however, the national front-page news described an experiment sponsored by the U.S. government. In Macon County, Alabama, a large group of Black men had gone untreated for syphilis. Over 4 decades, as some of them died, the U.S. government went to great lengths to ensure that the men in the Tuskegee Study were denied treatment, even after penicillin had become the standard of care in the mid-1940

    Centrifuge liquefaction tests in a laminar box

    Get PDF
    The difficulties associated with instrumenting earthquake sites in order to record pore pressure changes in a future event led to the use of scaled model tests performed in a centrifuge. Both dry and saturated sands were employed, contained in a box constructed of aluminium laminae designed to move freely on each other. This would result in shearing distortions developing in the soil unimpeded by the container. Accelerometers, displacement transducers and pore pressure sensors were attached to the box and embedded in the soil at various elevations so as to record the response of the soil to an earthquake-like excitation supplied to the base of the container. A special apparatus was constructed to imitate earthquake motion. In some tests on saturated sand, the soil profile was liquefied. Test results of accelerations, lateral and vertical displacements and pore pressures against time for typical earthquake inputs are given. The data, obtained under controlled conditions, can be compared with the various calculation methods for dynamically generated pore pressures
    • …
    corecore