18,690 research outputs found

    Effects of conversation interference on annoyance due to aircraft noise

    Get PDF
    The annoyance and interference effects of aircraft flyover noise on face to face conversation were investigated. Twenty 5 minute sessions, each composed of three flyovers, were presented to each of 20 pairs of female subjects in a simulated living room. Flyovers varied in peak noise level (55-79 dB, A-weighted) and spectrum (low or high frequency components). Subjects engaged in conversation for 10 sessions and in reverie for the other 10 sessions, and completed subjective ratings following every session. Annoyance was affected by noise level, but was not significantly different for the two activities of reverie and conversation. A noise level of 77 db was found unacceptable for conversation by 50 percent of the subjects. Conversation interference was assessed by incidence of increased vocal effort and/or interruption of conversation during flyovers. Although conversation interference increased with noise level, the conversation interference measures did not improve prediction of individual annoyance judgments

    Static feed water electrolysis module

    Get PDF
    An advanced static feed water electrolysis module (SFWEM) and associated instrumentation for generating breathable O2 was developed. The system also generates a H2 byproduct for use in an air revitalization system for O2 recovery from metabolic CO2. Special attention was given to: (1) eliminating water feed compartment degassing, (2) eliminating need for zero gravity condenser/separators, (3) increasing current density capability, and (4) providing a self contained module so that operation is independent of laboratory instrumentation and complicated startup/shutdown procedures

    Determination of ASPS performance for large payloads in the shuttle orbiter disturbance environment

    Get PDF
    A high fidelity simulation of the annular suspension and pointing system (ASPS), its payload, and the shuttle orbiter was used to define the worst case orientations of the ASPS and its payload for the various vehicle disturbances, and to determine the performance capability of the ASPS under these conditions. The most demanding and largest proposed payload, the Solar Optical Telescope was selected for study. It was found that, in all cases, the ASPS more than satisfied the payload's requirements. It is concluded that, to satisfy facility class payload requirements, the ASPS or a shuttle orbiter free-drift mode (control system off) should be utilized

    Advanced combined iodine dispenser and detector

    Get PDF
    A total weight of 1.23 kg (2.7 lb), a total volume of 1213 cu m (74 cu in), and an average power consumption of 5.5W was achieved in the advanced combined iodine dispenser/detector by integrating the detector with the iodine source, arranging all iodinator components within a compact package and lowering the parasitic power to the detector and electronics circuits. These achievements surpassed the design goals of 1.36 kg (3.0 lb), 1671 cu m (102 cu in) and 8W. The reliability and maintainability were improved by reducing the detector lamp power, using an interchangeable lamp concept, making the electronic circuit boards easily accessible, providing redundant water seals and improving the accessibility to the iodine accumulator for refilling. The system was designed to iodinate (to 5 ppm iodine) the fuel cell water generated during 27 seven-day orbiter missions (equivalent to 18,500 kg (40,700 lb) of water) before the unit must be recharged with iodine crystals

    Occasional Paper No. 092-1: Health Care Perceptions of Nebraska\u27s Urban & Rural Aged

    Get PDF
    Random samples were drawn in Douglas County, Nebraska (N = 196, mean age = 73.8 years), in the counties surrounding Douglas County also served by the Eastern Nebraska Office on Aging (N = 104, mean age = 72.4 years), and in eleven of the rural Sandhills counties of Nebraska (N = 200, mean age = 76.6). Participants responded to structured interviews of 169 questions that included self-assessed health status, availability of health care and physician services, costs, attitudes toward health care services, health experiences and beliefs. While the Sandhills respondents were significantly older and had less access to health services, they also had fewer annual days of hospitalization. There were no differences in subjective ratings of health or in levels of satisfaction with health care or availability

    Social Conditions of Nebraska\u27s Elderly

    Get PDF
    In 1991, the authors conducted a study of 500 older Nebraskans, comparing 300 people in Omaha and its surrounding counties with a sample of 200 who lived in the very rural Sandhills counties. The purpose of that study was to compare health and health care experience and satisfaction between urban and rural-dwelling elders. Random samples of older people were identified and interviewed by trained telephone operators; each interview took about a half hour. People were asked about their experiences with health and illness, the distance to their primary source of medical care and the distance to the hospital they use, their levels of satisfaction with that health care provider and hospital, their experience with dental care and satisfaction with it, and a number of questions dealing with their health beliefs. Levels of functioning and disability were also assessed through activities of daily living scales

    Numbering of Fullerenes (IUPAC Recommendations 2004)

    Get PDF
    Rules for numbering (C60-Ih)[5,6]fullerene and (C70-D5h(6))[5,6]fullerene were codified in a publication "Nomenclature for the (C60-Ih)[5,6] and (C70-D5h(6))[5,6]fullerenes” published in Pure Appl. Chem.74 (4), 629-695 (2002). The current publication contains recommendations for numbering a wide variety of fullerenes of different sizes, with rings of different sizes, from C20 to C120, and of various point group symmetries, including low symmetries such as Cs, Ci, and C1, as well as many fullerenes that have been isolated and well characterized as pristine carbon allotropes or as derivatives. These recommendations are based on the principles established in the earlier publication and aim at the identification of a well-defined and preferably contiguous helical pathway for numbering. Rules for systematically completing the numbering of fullerene structures for which a contiguous numbering pathway becomes discontiguous are presente

    How to Buy a Continent: The Protocols of Indian Treaties as Developed by Benjamin Franklin and Other Members of the American Philosophical Society

    Get PDF
    In 1743, when Benjamin Franklin announced the formation of an American Philosophical Society for the Promotion of Useful Knowledge, it was important for the citizens of Pennsylvania to know more about their American Indian neighbors. Beyond a slice of land around Philadelphia, three quarters of the province were still occupied by the Delaware and several other Indian tribes, loosely gathered under the wing of an Indian confederacy known as the Six Nations. Relations with the Six Nations and their allies were being peacefully conducted in a series of so-called “Indian Treaties” that dealt with the fur trade, threats of war with France, settlement of grievances, and the purchase of land

    A Re-evaluation of Evidence for Light Neutral Bosons in Nuclear Emulsions

    Full text link
    Electron-positron pair-production data obtained by bombardment of emulsion detectors with either cosmic rays or projectiles with mass between one and 207 and kinetic energies between 18 GeV and 32 TeV have been re-analysed using a consistent and conservative model of the background from electromagnetic pair conversion. The combined data yield a spectrum of putative neutral bosons decaying to e+e- pairs, with masses between 3 and 20 MeV/c^2 and femtosecond lifetimes. The statistical significance against background for these "X-bosons" varies between 2 and 8 sigma. The cross-section for direct production of X-bosons increases slowly with projectile energy, remaining over 1,000 times smaller the the pion production cross-section.Comment: major revision with improved figures; accepted by Int J Mod Phys
    corecore