45 research outputs found

    Hydrogen detection study

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    The effectiveness was assessed of a hydrogen (H2) detection concept for regenerative environmental control life support systems (EC/LSS). The concept evaluated was that utilized for the electrochemical depolarized concentrator (EDC) design, constructed, and tested for the EC/LSS space station prototype program. The EDC contains combustible gas detectors (CGDs) which were evaluated with H2. The CGDs were evaluated for linearity, position sensitivity, reproducibility, ambient effects, repeatability, speed of response, recovery time, and interchangeability. The effectiveness of CGDs located within the EDC for sensing H2 leaks at various line replaceable units in the subsystem was determined. The effects of H2 leak rate, H2 concentration of leaking gas and air currents in the vicinity of the EDC were determined. Proposed improvements for the H2 detection concept were documented and alternative H2 detection approaches were identified and analyzed

    Advanced solid electrolyte cell for CO2 and H2O electrolysis

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    A solid electrolyte cell with improved sealing characteristics was examined. A tube cell was designed, developed, fabricated, and tested. Design concepts incorporated in the tube cell to improve its sealing capability included minimizing the number of seals per cell and moving seals to lower temperature regions. The advanced tube cell design consists of one high temperature ceramic cement seal, one high temperature gasket seal, and three low temperature silicone elastomer seals. The two high temperature seals in the tube cell design represent a significant improvement over the ten high temperature precious metal seals required by the electrolyzer drum design. For the tube cell design the solid electrolyte was 8 mole percent yttria stabilized zirconium oxide slip cast into the shape of a tube with electrodes applied on the inside and outside surfaces

    The development of an electrochemical technique for in situ calibrating of combustible gas detectors

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    A program to determine the feasibility of performing in situ calibration of combustible gas detectors was successfully completed. Several possible techniques for performing the in situ calibration were proposed. The approach that showed the most promise involved the use of a miniature water vapor electrolysis cell for the generation of hydrogen within the flame arrestor of a combustible gas detector to be used for the purpose of calibrating the combustible gas detectors. A preliminary breadboard of the in situ calibration hardware was designed, fabricated and assembled. The breadboard equipment consisted of a commercially available combustible gas detector, modified to incorporate a water vapor electrolysis cell, and the instrumentation required for controlling the water vapor electrolysis and controlling and calibrating the combustible gas detector. The results showed that operation of the water vapor electrolysis at a given current density for a specific time period resulted in the attainment of a hydrogen concentration plateau within the flame arrestor of the combustible gas detector

    Evaluation and characterization of the methane-carbon dioxide decomposition reaction

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    A program was conducted to evaluate and characterize the carbon dioxide-methane (CO2-CH4) decomposition reaction, i.e., CO2 + CH4 = 2C + 2H2O. The primary objective was to determine the feasibility of applying this reaction at low temperatures as a technique for recovering the oxygen (O2) remaining in the CO2 which exits mixed with CH4 from a Sabatier CO2 reduction subsystem (as part of an air revitalization system of a manned spacecraft). A test unit was designed, fabricated, and assembled for characterizing the performance of various catalysts for the reaction and ultraviolet activation of the CH4 and CO2. The reactor included in the test unit was designed to have sufficient capacity to evaluate catalyst charges of up to 76 g (0.17 lb). The test stand contained the necessary instrumentation and controls to obtain the data required to characterize the performance of the catalysts and sensitizers tested: flow control and measurement, temperature control and measurement, product and inlet gas analysis, and pressure measurement. A product assurance program was performed implementing the concepts of quality control and safety into the program effort

    Six-man, self-contained carbon dioxide concentrator system

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    A six man, self contained electrochemical carbon dioxide concentrating subsystem was successfully designed and fabricated. It was a preprototype engineering model designed to nominally remove 6.0 kg (13.2 lb) CO2/day with an inlet air CO2 partial pressure of 400 N/sq m (3 mm Hg) and an overcapacity removal capability of 12.0 kg (26.4 lb) CO2/day. The design specifications were later expanded to allow operation at space station prototype CO2 collection subsystem operating conditions

    Six-man, self-contained carbon dioxide concentrator subsystem for Space Station Prototype (SSP) application

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    A six man, self contained, electrochemical carbon dioxide concentrating subsystem for space station prototype use was successfully designed, fabricated, and tested. A test program was successfully completed which covered shakedown testing, design verification testing, and acceptance testing

    Precarious, Always-On and Flexible: A Case Study of Academics as Information Workers

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    The higher education landscape has changed in the last decades. The neoliberal restructuring of universities has led to transformations such as reducing public expenditure, allocating resources based on competition and quasi-market disciplines. These structural transformations have also an effect on the working conditions, practices and relations of subjects within universities. Questions that need to be addressed: How do different working contexts and conditions in the academia shape feelings of autonomy, flexibility and reputation on the one hand and precariousness, overwork and dissatisfaction on the other? What are the broader political realities and potentials in terms of solidarity, participation and democracy at universities? I address these questions based on a theoretical analysis and qualitative interviews with precariously employed academics

    ‘Get yourself some nice, neat, matching box files’: research administrators and occupational identity work

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    To date, qualitative research into occupational groups and cultures within academia has been relatively scarce, with an almost exclusive concentration upon teaching staff within universities and colleges. This article seeks to address this lacuna and applies the interactionist concept of ‘identity work’ in order to examine one specific group to date under-researched: graduate research administrators. This occupational group is of sociological interest as many of its members appear to span the putative divide between ‘academic’ and ‘administrative’ occupational worlds within higher education. An exploratory, qualitative research project was undertaken, based upon interviews with 27 research administrators. The study analyses how research administrators utilise various forms of identity work to sustain credible occupational identities, often in the face of considerable challenge from their academic colleagues

    The Kafkaesque Pursuit of ‘World Class’: Audit Culture and the Reputational Arms Race in Academia

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    Since the 1980s universities have been subjected to a seemingly continuous process of policy reforms designed to make them more economical, efficient and effective, according to yardsticks defined by governments and university managers. The pursuit of ‘excellence’, ‘international standing’ and ‘world class’ status have become key drivers of what Hazelkorn (High Educ Pol 21(2):193–215, 2008) has termed the ‘rankings arms race’ that now dominates the world of academia. These policies are changing the mission and meaning of the public university and, more profoundly, the culture of academia itself. While some authors have sought to capture and analyse these trends in terms of ‘academic capitalism’ and the ‘enterprise university model’, we suggest they might also be usefully understood theoretically as illustrations of the rise of audit culture in higher education and its effects. Drawing on ethnographic examples from the UK, Denmark and New Zealand, we ask: how are higher education institutions being reconfigured by these new disciplinary regimes of audit? How are ranking and performance indicators changing institutional behaviour and transforming academic subjectivities? What possibilities are there for alternative university futures? And what insights can anthropology offer to address these questions

    Relative distancing: a grounded theory of how learners negotiate the interprofessional.

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    A number of extant educational, psychological and sociological theories have been suggested as possessing utility for interprofessional education (IPE). However, there is limited theory proposed that has been derived directly from data. This article adds to the theoretical toolkit by theorizing from data using constructionist grounded theorizing. This article discusses the grounded theorizing of participants' approaches to IPE and describes the social process of relative distancing, a collection of strategies employed by participants to construct their own professional identities and negotiate their way through interprofessional interactions. The categories of relative distancing are conceptualized as (1) integrating the professional and the interprofessional; (2) constellating and maintaining distance; (3) tensioning and manipulating distance and (4) the dimensions of distance. The first, and most theoretically integrative, category will be discussed in detail here. It was found that participants valued certain learning outcomes over others. They favored learning opportunities that were perceived to be of direct relevance to their own professional development and contributed finite personal resources to these. Resources were committed to those interprofessional learning opportunities where relevance was perceived and the conditions of co-presence (with other professions) and a context for interaction were achieved. The discussion draws links between the data and contemporary discourses of economics and identity
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