13,997 research outputs found

    VLA-Max '91 tests of high energy flare physics

    Get PDF
    The potential for the Very Large Array (VLA) contributions during the coming maximum in solar activity is illustrated by unpublished observations of solar flares on 28 May, 8 June, 24 June, and 30 September 1988. Some of this data appears in the two papers by Willson et al., referenced in this article. The VLA can be used to spatially resolve flaring active regions and their magnetic fields. These results can be compared with simultaneous x ray and gamma ray observations from space. Examples are provided in which spatially separated radio sources are resolved for the pre-burst, impulsive and decay phases of solar flares. The emergence of precursor coronal loops probably triggers the release of stored magnetic energy in adjacent coronal loops. Noise storm enhancements can originate in large-scale coronal loops on opposite sides of the visible solar disk. An interactive feedback mechanism may exist between activity in high-lying 90 cm coronal loops and lower-lying 20 cm ones

    Advanced engineering design program at the University of Illinois for the 1987-1988 academic year

    Get PDF
    The participation of the University of Illinois at Urbana-Champaign in the NASA/USRA Universities Advanced Engineering Design Program (Space) is reviewed for the 1987 to 88 academic year. The University's design project was the Manned Marsplane and Delivery System. In the spring of 1988 semester, 107 students were enrolled in the Aeronautical and Astronautical Engineering Departments' undergraduate Aerospace Vehicle Design course. These students were divided into an aircraft section (responsible for the Marsplane design), and a spacecraft section (responsible for the Delivery System Design). The design results are presented in Final Design Reports, copies of which are attached. In addition, five students presented a summary of the design results at the Program's Summer Conference

    Compact, variable, moving sources observed on the sun at 2 centimeters wavelength

    Get PDF
    The Very Large Array (VLA) was used to observe the active region AT 4508 in the C-configuration between 1530 and 2330 UT on June 4, 1984. The position of this region was N06 E57 at 1300 UT on this day. Followup observations were made between 1500 and 2300 UT on January 17, 1986 in the D-configuration. Observations were compared with Mt. Wilson magnetograms. Results are discussed

    Diverse Aging and Health Inequality by Race and Ethnicity

    Get PDF
    Although gerontologists have long embraced the concept of heterogeneity in theories and models of aging, recent research reveals the importance of racial and ethnic diversity on life course processes leading to health inequality. This article examines research on health inequality by race and ethnicity and identifies theoretical and methodological innovations that are transforming the study of health disparities. Drawing from cumulative inequality theory, we propose greater use of life course analysis, more attention to variability within racial and ethnic groups, and better integration of environmental context into the study of accumulation processes leading to health disparities

    Early Origins of Adult Cancer Risk Among Men and Women: Influence of Childhood Misfortune?

    Get PDF
    Objective—To examine the effect of five childhood misfortune domains—parental behavior, socioeconomic status, infectious diseases, chronic diseases, and impairments—on all-site and selected site-specific cancer prevalence and all-site cancer incidence. Method—Panel data from the Health and Retirement Study (2004–2012) were used to investigate cancer risk among adults above the age of 50. Results—Risky parental behavior and impairment in childhood were associated with higher odds of all-site cancer prevalence, and childhood chronic disease was associated with prostate cancer, even after adjusting for adult health and socioeconomic factors. Moreover, having one infectious disease in childhood lowered the odds of colon cancer. Cancer trends varied by race and ethnicity, most notably, higher prostate cancer prevalence among Black men and lower all-site cancer among Hispanic adults. Discussion—These findings underscore the importance of examining multiple domains of misfortune because the type and amount of misfortune influence cancer risk in different ways

    Top, Bottom Quarks and Higgs Bosons

    Get PDF
    In this talk, I will discuss possible new physics effects that modify the interaction of Higgs boson(s) with top and bottom quarks, and discuss how to detect such effects in current and future high energy colliders.Comment: LaTeX, 16 pages including 5 figure

    ROBOSIM: An intelligent simulator for robotic systems

    Get PDF
    The purpose of this paper is to present an update of an intelligent robotics simulator package, ROBOSIM, first introduced at Technology 2000 in 1990. ROBOSIM is used for three-dimensional geometrical modeling of robot manipulators and various objects in their workspace, and for the simulation of action sequences performed by the manipulators. Geometric modeling of robot manipulators has an expanding area of interest because it can aid the design and usage of robots in a number of ways, including: design and testing of manipulators, robot action planning, on-line control of robot manipulators, telerobotic user interface, and training and education. NASA developed ROBOSIM between 1985-88 to facilitate the development of robotics, and used the package to develop robotics for welding, coating, and space operations. ROBOSIM has been further developed for academic use by its co-developer Vanderbilt University, and has been in both classroom and laboratory environments for teaching complex robotic concepts. Plans are being formulated to make ROBOSIM available to all U.S. engineering/engineering technology schools (over three hundred total with an estimated 10,000+ users per year)
    • …
    corecore