2,495 research outputs found

    Electrolytic pretreatment unit gaseous effluent conditioning

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    The electrolytic pretreatment of urine is an advanced process that eliminates the need for handling and storing the highly corrosive chemicals that are normally used in water reclamation systems. The electrolytic pretreatment process also converts the organic materials in urine to gases (N2 and O2) that can be used to replenish those lost to space by leakage, venting, and air lock operations. The electrolytic process is more than a pretreatment, since it decreases the urine solids content by approximately one third, thus reducing the load and eventual solids storage requirements of the urine processing system. The evolved gases from the pretreatment step cannot, however, be returned directly to the atmosphere of a spacecraft without first removing several impurities including hydrogen, chlorine, and certain organic compounds. A treatment concept was developed that would decrease the impurities in the gas stream that emanates from an electrolysis unit to levels sufficiently low to allow the conditioned gas stream to be safely discharged to a spacecraft atmosphere. Two methods were experimentally demonstrated that can accomplish the desired cleanup. The bases of the two methods are, repectively: (1) raw urine scrubbing and (2) silica gel sorption

    Pre- and posttreatment techniques for spacecraft water recovery

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    The objective was to develop techniques for satisfactory pretreatment of waste water (urine and wash water) prior to recovery by distillation and satisfactory post-treatment of the recovered water and humidity condensate for purification to the high quality necessary for reuse. The effort included literature and laboratory investigations, feasibility evaluations of candidate approaches, and development of conceptual designs for a waste water pretreatment system and a recovered water post-treatment system

    Water system microbial check valve development

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    Development work on a device for the Space Shuttle that will prevent the transfer of viable microorganisms within water systems is described. The device serves as a check valve in that it prevents the transfer or cross-contamination of microorganisms from a nonpotable system into a potable water system when these systems are interconnected. In this regard, the function of the device is similar to that of the air gap found in conventional one gravity systems. The device is essentially a bed of resin material impregnated with iodine. Basic design data for a variety of flow and temperature conditions are presented, together with results of challenging the beds with suspensions of seven microorganisms including aerobes, anaerobes, and spore formers

    Experimental study of the constituents of space wash water

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    This report presents experimental data, obtained under controlled conditions, which quantify the various constituents of human origin that may be expected in space wash water. The experiments were conducted with a simulated crew of two male and two female subjects. The data show that the expected wash water contaminants originating from human secretions are substantially lower than theoretical projections indicated. The data presented are immediately useful and may have considerable impact on the tradeoff comparisons among various unit processes and systems under consideration by NASA for recycling space wash water

    Mind and body, form and content: how not to do petitio principii analysis

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    Few theoretical insights have emerged from the extensive literature discussions of petitio principii argument. In particular, the pattern of petitio analysis has largely been one of movement between the two sides of a dichotomy, that of form and content. In this paper, I trace the basis of this dichotomy to a dualist conception of mind and world. I argue for the rejection of the form/content dichotomy on the ground that its dualist presuppositions generate a reductionist analysis of certain concepts which are central to the analysis of petitio argument. I contend, for example, that no syntactic relation can assimilate within its analysis the essentially holistic nature of a notion like justification. In this regard, I expound a form of dialectical criticism which has been frequently employed in the philosophical arguments of Hilary Putnam. Here the focus of analysis is upon the way in which the proponent of a position proceeds to explain or argue for his/her own particular theses. My conclusion points to the use of such dialectic within future analyses of petitio principii

    Impact Investing Innovation: Bringing Together Public, Private and Third Sectors to Create Greater Value: The Case of the Public Private Partnership Initiative for the New Public Hospital of Treviso

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    This chapter documents the first pilot project integrating the social impact investing dimension in a large infrastructure project: the project finance for the upgrande and extension of the public hospital in Treviso (Northern Italy). The case study is a compelling example of ‘Shared Value’ highlighting the potential and limits of the theoretical framework developed by Porter and Kramer (Harvard Business Review, 89(1–2), 62–77, 2011)

    A genetic network that suppresses genome rearrangements in Saccharomyces cerevisiae and contains defects in cancers.

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    Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes

    Social networks and labour productivity in Europe: An empirical investigation

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    This paper uses firm-level data recorded in the AMADEUS database to investigate the distribution of labour productivity in different European countries. We find that the upper tail of the empirical productivity distributions follows a decaying power-law, whose exponent α\alpha is obtained by a semi-parametric estimation technique recently developed by Clementi et al. (2006). The emergence of "fat tails" in productivity distribution has already been detected in Di Matteo et al. (2005) and explained by means of a model of social network. Here we show that this model is tested on a broader sample of countries having different patterns of social network structure. These different social attitudes, measured using a social capital indicator, reflect in the power-law exponent estimates, verifying in this way the existence of linkages among firms' productivity performance and social network.Comment: LaTeX2e; 18 pages with 3 figures; Journal of Economic Interaction and Coordination, in pres

    Building social capital through breastfeeding peer support: Insights from an evaluation of a voluntary breastfeeding peer support service in North-West England

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    Background: Peer support is reported to be a key method to help build social capital in communities. To date there are no studies that describe how this can be achieved through a breastfeeding peer support service. In this paper we present findings from an evaluation of a voluntary model of breastfeeding peer support in North-West England to describe how the service was operationalized and embedded into the community. This study was undertaken from May, 2012 to May, 2013. Methods: Interviews (group or individual) were held with 87 participants: 24 breastfeeding women, 13 peer supporters and 50 health and community professionals. The data contained within 23 monthly monitoring reports (January, 2011 to February 2013) compiled by the voluntary peer support service were also extracted and analysed. Results: Thematic analysis was undertaken using social capital concepts as a theoretical lens. Key findings were identified to resonate with ’bonding’, ‘bridging’ and ‘linking’ forms of social capital. These insights illuminate how the peer support service facilitates ‘bonds’ with its members, and within and between women who access the service; how the service ‘bridges’ with individuals from different interests and backgrounds, and how ‘links’ were forged with those in authority to gain access and reach to women and to promote a breastfeeding culture. Some of the tensions highlighted within the social capital literature were also identified. Conclusions: Horizontal and vertical relationships forged between the peer support service and community members enabled peer support to be embedded into care pathways, helped to promote positive attitudes to breastfeeding and to disseminate knowledge and maximise reach for breastfeeding support across the community. Further effort to engage with those of different ethnic backgrounds and to resolve tensions between peer supporters and health professionals is warranted

    Social capital, social inclusion and changing school contexts: a Scottish perspective

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    This paper synthesises a collaborative review of social capital theory, with particular regard for its relevance to the changing educational landscape within Scotland. The review considers the common and distinctive elements of social capital, developed by the founding fathers – Putnam, Bourdieu and Coleman – and explores how these might help to understand the changing contexts and pursue opportunities for growth
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