2,112 research outputs found

    Preliminary assessment of power-generating tethers in space and of propulsion for their orbit maintenance

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    The concept of generating power in space by means of a conducting tether deployed from a spacecraft was studied. Using hydrogen and oxygen as the rocket propellant to overcome the drag of such a power-generating tether would yield more benefit than if used in a fuel cell. The mass consumption would be 25 percent less than the reactant consumption of fuel cells. Residual hydrogen and oxygen in the external tank and in the orbiter could be used very effectively for this purpose. Many other materials (such as waste from life support) could be used as the propellant. Electrical propulsion using tether generated power can compensate for the drag of a power-generating tether, half the power going to the useful load and the rest for electric propulsion. In addition, the spacecraft's orbital energy is a large energy reservoir that permits load leveling and a ratio of peak to average power equal to 2. Critical technologies to be explored before a power-generating tether can be used in space are delineated

    Air cushion vehicles: A briefing

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    Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described

    Spacecraft cost estimation

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    Spacecraft subsystem cost estimatio

    Computer optimization of reactor-thermoelectric space power systems

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    A computer simulation and optimization code that has been developed for nuclear space power systems is described. The results of using this code to analyze two reactor-thermoelectric systems are presented

    Persuasion: an analysis and common frame of reference for IS research

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    Information Systems (IS) researchers persistently examine how Information and Communications Technology (ICT) changes attitudes and behaviours but rarely leverage the persuasion literature when doing so. The hesitance of IS researchers to leverage persuasion literature may be due to this literature’s well-documented complexity. This study aims to reduce the difficulty of understanding and applying persuasion theory within IS research. The study achieves this aim by developing a common frame of reference to help IS researchers to conceptualise persuasion and to conceptually differentiate persuasion from related concepts. In doing this, the study also comprehensively summarises existing research and theory and provides a set of suggestions to guide future IS research into persuasion and behaviour change

    Service Co-Creation with the Customer: the Role of Information Systems

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    The Epidemic of Neonatal Abstinence Syndrome, Historical References of Its Origins, Assessment, and Management

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    Neonatal abstinence syndrome (NAS) refers to a constellation of signs that are present in some newborn infants resulting from the abrupt cessation of passive transfer of maternal opioids used during pregnancy. The classic NAS refers to infants born to mothers who used opioids during pregnancy, but the term has broadened to include infants whose mothers have used or abused other psychoactive substances during pregnancy that contribute to the expression of the syndrome. Pregnant women who use opioids do so illicitly, and/or as medically prescribed for pain relief, and/or as medication assisted treatment for opioid dependence. The first case of NAS in infants and the subsequent treatment (or lack thereof) was reported in 1875 and was called Congenital Morphinism. By 2012, the incidence of NAS increased to more than 30 per 1,000 hospital live births, along with an increase in the number of infants being treated pharmacologically for NAS, resulting in an increase in the length of stay and healthcare expenses. We present historical references on NAS, the various factors and events that led to its increasing prevalence and today\u27s current epidemic. We also review the current tools to assess infants with NAS and treatment options in its management

    Open vs.Closed standards for ambient intelligence: an exploratory study of adoption

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    Emerging forms of structurally complex information systems, such as Ambient Intelligence (AmI), requires the integration of a range of technologies. To enable such systems’ development there is a reliance on interoperability standards. However, due to their inherent characteristics, the adoption of open or closed standards by technology vendors can have impacts the later stages of the adoption and diffusion of systems. This paper reports on research-in-progress which explores the adoption of open and closed standards by technology vendors engaged in AmI development. Existing models of innovation adoption and diffusion fail to adequately account for adoption in more complex technological contexts. In order to address such deficiencies, current perspectives on standards are discussed, before a conceptual framework for structuring the research is proposed which integrates both existing adoption theory and standards-oriented research. The use of the European Consumer Electronics sector as a unit of analysis is discussed, before concluding with an overview of how the study will progress

    Nerve agents: A guide for emergency nurses. Part 1

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    Recent incidents in the UK and the alleged chemical attacks in Syria by the Bashar al-Assad regime have brought the subject of chemical weapons back into the public domain. To date these types of event have been relatively rare because terrorist plans to harm large numbers of people have mostly been thwarted. This is the first part of a two-part article on nerve agents. Part one gives an overview of these agents, their historical background and manufacture, and how the agents affect physiology. Part two, which will appear in the next issue, considers the pre-hospital response to the use of nerve agents, including effective triage and decontamination, and in-hospital treatment
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