7,869 research outputs found

    Experimental and CFD airflow studies of a cleanroom with special respect to air supply inlets

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    Investigations were carried out into the airflow in a non-unidirectional airflow cleanroom and its affect on the local airborne particle cleanliness The main influence was the method of air supply A supply inlet with no diffuser gave a pronounced downward jet flow and low levels of contamination below it, but poorer than average conditions in much of the rest of the room A 4-way diffuser gave much better air mixing and a more even airborne particle concentration throughout the cleanroom Other variables such as air inlet supply velocity, temperature difference between air supply and the room, and the release position of contamination also influenced the local airborne cleanliness A CFD analysis of airflow fields in a cleanroom was compared with measured values It was considered that a turbulent intensity of 6%, and a hydraulic diameter based on the actual size of the air inlet, should be used for the inlet boundary conditions and, when combined with a k-epsilon standard turbulence model, a reasonable prediction of the airflow and airborne particle concentration was obtained

    Particle and microbial airborne dispersion from people

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    The airborne dispersion of particles from 55 people (30 females and 25 males) was measured. The dispersion per minute of microbe carrying particles (MCPs) averaged 2,400 when wearing personal indoor clothing, and 177 when wearing cleanroom garments. One exceptional person, whose dispersal rates were not included in these results, dispersed 11,000 per minute when wearing cleanroom garments. The dispersion rate of particles ≥5μm per minute averaged 332,000 when wearing indoor clothing, and 37,300 when wearing cleanroom garments. The dispersion rate of particles ≥0.5μm per minute averaged 2,130,000 when wearing indoor clothing, and 1,020,000 when wearing cleanroom garments. The dispersion rates for particles and MCPs were higher in males than females. Depending on the method used, the average equivalent particle diameter of the MCPs was 9μm or 18μm. There was no situation where the dispersion of MCPs was not accompanied by substantial numbers of both ≥0.5μm and ≥5.0μm airborne particles, and there appears to be little advantage in measuring particles ≥5.0μm when using airborne particle counting to indirectly monitor the dispersion of MCPs. When wearing cleanroom garments, the ratio of ≥0.5μm particles to MCPs was found to average 5,800:1, and for ≥5.0μm particles it was 210:1

    Investigating the Impact of the Spatial Distribution of Deprivation on Health Outcomes

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    A comprehensive survey of hearing questionnaires: how many are there, what do they measure, and how have they been validated?

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    The self-report questionnaire is a popular tool for measuring outcomes in trials of interventions for hearing impairment. Many have been designed over the last fifty years, and there is no single standard questionnaire that is widely accepted and used. We felt it would be a valuable resource to have a comprehensive collection of all adult hearing-loss questionnaires (excluding those wholly devoted to tinnitus, children, or cochlear implants) and to survey their degree of validation. We collated copies of every published hearing difficulty questionnaire that we could find. The search was primarily done by iterative reference searching. Questionnaire topics were obtained by mapping the text of each questionnaire onto a set of categories; reports of validation methods were taken from the primary paper(s) on each questionnaire. In total we found 139 hearing-specific questionnaires (though many others were found that were primarily about something else). Though not formally systematic, we believe that we have included every questionnaire that is important, most of those of some notice, and a fair fraction of those obscure. We classified 111 as “primary” and the remaining 28 as “contractions”, being shortened versions of a primary without any new questions. In total, there were 3618 items across all the primary questionnaires. The median number of items per questionnaire was 20; the maximum was 158. Across all items, about one third were concerned with the person’s own hearing, another third with the repercussions of it, and about a quarter with hearing aids. There was a wide range in validation methods, from only using items chosen statistically from wider pools and with formal validation against independent measures of clinical outcomes, to just reporting a correlation with an audiogram measure of hearing loss. The “state of play” of the field of hearing questionnaires will be discussed

    The subjective effect of multiple co-channel frequency modulated television interference

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    As the geostationary orbit/spectrum becomes saturated, there is a need for the ability to reuse frequency assignments. Protection ratios (the ratio of wanted signal power to interfering signal power at the receiver) play a key role in determining efficient frequency reuse plans. A knowledge of the manner in which multiple sources of co-channel interference combine is vital in determining protection ratio requirements such that suitable margin may be allocated for multiple interfering signals. Results of tests examining the subjective assessment of multiple co-channel frequency modulated television signals interfering with another frequency modulated TV system are presented

    'Bring us the female condom': HIV intervention, gender and political empowerment in two South African communities

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    The quotation which heads this paper encapsulates two important issues in AIDS research in South Africa: the one is substantive, the other methodological. The link between them is the rapid spread of HIV/AIDS in the country and the indication not only that women are more at risk of infection than men, but that, as in many other parts of the world, much of their vulnerability is gender based. ‘Bring us the female condom’ sums up the response of one particular group of black South African women to AIDS education. Their demand was a reflection of their relative domestic and gender empowerment - and also a high degree of political mobilization. However, their position is not necessarily shared by other black women. But the call for the female condom went further: it was a challenge to rethink our position as researchers and particularly to face the implications of commitment to a participatory model of community based intervention research

    Elderly Patients’ Perception of Pain Management after Open and Reduction Internal Fixation Surgery

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    Little is known about pain and pain management in older adults who experience open reduction and internal fixation (ORIF) surgery. This qualitative descriptive phenomenological study explored two research questions: (a) What are the perceptions of pain and pain management in patients between 65 and 75 years of age, 48 hours after ORIF surgery in a community hospital? (b) What are the perceptions of adaptation after ORIF? A pilot study included four patients in two units of a Southern California hospital, followed by open ended, semi-structured interviews with 10 participants. Four themes emerged: (a) elderly patients experience different patterns of pain and coping mechanisms; (b) elderly patients experience pain after gaining consciousness from ORIF surgery; (c) effective pain management requires patients’ empowerment and opportunity to participate in pain management decisions; (d) elderly patients perceive adaptation as a process of change and acceptance. Multimodal pain management strategies, including regional opioids and systemic anti-inflammatories, could reduce post-operative, generalized bio-physiological stress experienced by elderly patients

    Balancing Care and Authenticity in Digital Collections: A Radical Empathy Approach To Working With Disk Images

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    Both traditional recordkeeping and radical empathy frameworks ask us to carefully consider: the presence of sensitive information within digital content; those who created, are captured by, and are affected by a record (or the absence of that record); and the consequences of retaining or discarding that information. However, automated digital archiving workflows – in order to handle the scale and volume of digital content – discourage contextual and empathetic decision-making in favour of preselected decisions. This paper explores the implications on labor and privacy of the common practice to “take and keep it all” within the context of radical empathy. Practices which promote retention of complete disk images and encourage the creation of access copies with redacted sensitive data are vulnerable. The decision to discard must be deliberate and, often, must be enacted manually, outside of the workflow. The motivation for this model is that the researcher, archivist, curator, or librarian can always return to the original disk image in order to demonstrate authenticity, allow for emulation or access, or to generate new access copies. However, this practice poses ethical privacy concerns and does not demonstrate care. We recognize that the resources necessary to review disk images and make contextual decisions that balance both privacy and authenticity are sizable due to the manual nature of this work: this places strain and further labor on staff and practitioners using current digital archival and preservation tools. We proffer that there is a need to develop tools which aid in efficient and explicit redaction, but also allow for needed contextual and empathetic decision-making. Further we propose that more staff time is required to make these decisions and if that staff time is not available, then the institution should consider itself incapable of ethically stewarding the content and protecting those affected. Pre-print first published online 01/24/202
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