7,463 research outputs found

    Effect of present technology on airship capabilities

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    The effect is presented of updating past airship designs using current materials and propulsion systems to determine new airship performance and productivity capabilities. New materials and power plants permit reductions in the empty weights and increases in the useful load capabilities of past airship designs. The increased useful load capability results in increased productivity for a given range, i.e., either increased payload at the same operating speed or increased operating speed for the same payload weight or combinations of both. Estimated investment costs and operating costs are presented to indicate the significant cost parameters in estimating transportation costs of payloads in cents per ton mile. Investment costs are presented considering production lots of 1, 10 and 100 units. Operating costs are presented considering flight speeds and ranges

    Postcard: Soldiers\u27 Reunion, City Park, Dodge City, Kansas

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    This colorized photographic postcard features a Reunion of Veterans in Dodge City, Kansas. The photo portrays a walking path with trees, tents and people to the left. On the right side of the path is trees and tents. People are sitting in chairs in front of the tents. Red print is on the bottom left of the card. Printed text is on the left side of the card. The name and address has been typed with a typewriter. There is handwriting on the back.https://scholars.fhsu.edu/tj_postcards/1535/thumbnail.jp

    Vacancy ordering effects on the conductivity of yttria- and scandia-doped zirconia

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    Polarizable interaction potentials, parametrized using ab initio electronic structure calculations, have been used in molecular dynamics simulations to study the conduction mechanism in Y2 O3 - and Sc2 O3 -doped zirconias. The influence of vacancy-vacancy and vacancy-cation interactions on the conductivity of these materials has been characterised. While the latter can be avoided by using dopant cations with radii which match those of Zr4+ (as is the case of Sc3+), the former is an intrinsic characteristic of the fluorite lattice which cannot be avoided and which is shown to be responsible for the occurrence of a maximum in the conductivity at dopant concentrations between 8 and 13 %. The weakness of the Sc-vacancy interactions in Sc2 O3 -doped zirconia suggests that this material is likely to present the highest conductivity achievable in zirconias.Comment: 17 pages, 6 figur

    Characterizing heterogeneous dynamics at hydrated electrode surfaces

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    In models of Pt 111 and Pt 100 surfaces in water, motions of molecules in the first hydration layer are spatially and temporally correlated. To interpret these collective motions, we apply quantitative measures of dynamic heterogeneity that are standard tools for considering glassy systems. Specifically, we carry out an analysis in terms of mobility fields and distributions of persistence times and exchange times. In so doing, we show that dynamics in these systems is facilitated by transient disorder in frustrated two-dimensional hydrogen bonding networks. The frustration is the result of unfavorable geometry imposed by strong metal-water bonding. The geometry depends upon the structure of the underlying metal surface. Dynamic heterogeneity of water on the Pt 111 surface is therefore qualitatively different than that for water on the Pt 100 surface. In both cases, statistics of this adlayer dynamic heterogeneity responds asymmetrically to applied voltage.Comment: 6 page, 4 figure

    Solvation at Aqueous Metal Electrodes

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    We present a study of the solvation properties of model aqueous electrode interfaces. The exposed electrodes we study strongly bind water and have closed packed crystalline surfaces, which template an ordered water adlayer adjacent to the interface. We find that these ordered water structures facilitate collective responses in the presence of solutes that are correlated over large lengthscales and across long timescales. Specifically, we show that the liquid water adjacent to the ordered adlayers forms a soft, liquid-vapor-like interface with concomitant manifestations of hydrophobicity. Temporal defects in the adlayer configurations create a dynamic heterogeneity in the degree to which different regions of the interface attract hydrophobic species. The structure and heterogeneous dynamics of the adlayer defects depend upon the geometry of the underlying ordered metal surface. For both 100 and 111 surfaces, the dynamical heterogeneity relaxes on times longer than nanoseconds. Along with analyzing time scales associated with these effects, we highlight implications for electrolysis and the particular catalytic efficiency of platinum.Comment: 9 pages, 8 figure

    Object Matching in Distributed Video Surveillance Systems by LDA-Based Appearance Descriptors

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    Establishing correspondences among object instances is still challenging in multi-camera surveillance systems, especially when the cameras’ fields of view are non-overlapping. Spatiotemporal constraints can help in solving the correspondence problem but still leave a wide margin of uncertainty. One way to reduce this uncertainty is to use appearance information about the moving objects in the site. In this paper we present the preliminary results of a new method that can capture salient appearance characteristics at each camera node in the network. A Latent Dirichlet Allocation (LDA) model is created and maintained at each node in the camera network. Each object is encoded in terms of the LDA bag-of-words model for appearance. The encoded appearance is then used to establish probable matching across cameras. Preliminary experiments are conducted on a dataset of 20 individuals and comparison against Madden’s I-MCHR is reported

    Molecular dark matter in galaxies

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    Clouds containing molecular dark matter in quantities relevant for star formation may exist in minihaloes of the type of cold dark matter included in many cosmological simulations or in the regions of some galaxies extending far beyond their currently known boundaries. We have systematically explored parameter space to identify conditions under which plane-parallel clouds contain sufficient column densities of molecular dark matter that they could be reservoirs for future star formation. Such clouds would be undetected or at least appear by current observational criteria to be uninteresting from the perspective of star formation. We use a time-dependent PDR code to produce theoretical models of the chemistry and emission arising in clouds for our chosen region of parameter space. We then select a subset of model clouds with levels of emission that are low enough to be undetectable or at least overlooked by current surveys. The existence of significant column densities of cold molecular dark matter requires that the background radiation field be several or more orders of magnitude weaker than that in the solar neighbourhood. Lower turbulent velocities and cosmic ray induced ionization rates than typically associated with molecular material within a kpc of the Sun are also required for the molecular matter to be dark. We find that there is a large region within the parameter space that results in clouds that might contain a significant mass of molecular gas whilst remaining effectively undetectable or at least not particularly noticeable in surveys. We note briefly conditions under which molecular dark matter may contain a dynamically interesting mass.Comment: 9 pages, 2 figures, accepted for publication in A&A; additional concluding paragraph added at proof stag

    Consultation skills development in general practice: findings from a qualitative study of newly recruited and more experienced clinical pharmacists during the COVID-19 pandemic.

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    The new structured medication review (SMR) service was introduced into the National Health Service in England during the COVID-19 pandemic, following a major expansion of clinical pharmacists within new formations known as primary care networks (PCNs). The aim of the SMR is to tackle problematic polypharmacy through comprehensive, personalised medication reviews involving shared decision-making. Investigation of clinical pharmacists' perceptions of training needs and skills acquisition issues for person-centred consultation practice will help better understand their readiness for these new roles. A longitudinal interview and observational study in general practice. A longitudinal study of 10 newly recruited clinical pharmacists interviewed three times, plus a single interview with 10 pharmacists recruited earlier and already established in general practice, across 20 newly forming PCNs in England. Observation of a compulsory 2-day history taking and consultation skills workshop. A modified framework method supported a constructionist thematic analysis. Remote working during the pandemic limited opportunities for patient-facing contact. Pharmacists new to their role in general practice were predominantly concerned with improving clinical knowledge and competence. Most said they already practiced person-centred care, using this terminology to describe transactional medicines-focused practice. Pharmacists rarely received direct feedback on consultation practice to calibrate perceptions of their own competence in person-centred communication, including shared decision-making skills. Training thus provided knowledge delivery with limited opportunities for actual skills acquisition. Pharmacists had difficulty translating abstract consultation principles into specific consultation practices. SMRs were introduced when the dedicated workforce was largely new and being trained. Addressing problematic polypharmacy requires structural and organisational interventions to enhance the communication skills of clinical pharmacists (and other health professionals), and their use in practice. The development of person-centred consultation skills requires much more substantial support than has so far been provided for clinical pharmacists. [Abstract copyright: © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

    Alcohol, the overlooked drug: clinical pharmacist perspectives on addressing alcohol in primary care.

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    Attempts to routinely embed brief interventions in health systems have long been challenging, with healthcare professionals concerned about role adequacy, legitimacy, and support. This is the first study to explore clinical pharmacists' experiences of discussing alcohol with patients in their new role in UK primary care, in developing a novel approach to brief intervention. It investigates their confidence with the subject of alcohol in routine practice and explores views on a new approach, integrating alcohol into the medication review as another drug directly linked to the patient's health conditions and medicines, rather than a separated 'healthy living' issue. The study forms part of wider efforts to repurpose and reimagine the potential application of brief interventions and to rework their contents. Longitudinal qualitative study of 10 recruits to the new clinical pharmacist role in English primary care, involving three semi-structured interviews over approximately 16 months, supplemented by 10 one-off interviews with pharmacists already established in general practice. When raised at all, enquiring about alcohol in medication reviews was described in terms of calculating dose and level of consumption, leading to crude advice to reduce drinking. The idea was that those who appeared dependent should be referred to specialist services, though few such referrals were recalled. Pharmacists acknowledged that they were not currently considering alcohol as a drug in their practice and were interested in learning more about this concept and the approach it entailed, particularly in relation to polypharmacy. Some recognised a linked need to enhance consultation skills. Alcohol complicates routine clinical care and adversely impacts patient outcomes, even for those drinking at seemingly unremarkable levels. Changing clinical practice on alcohol requires engaging with, and supportively challenging, routine practices and entrenched ideas of different kinds. Framing alcohol as a drug may help shift the focus from patients with alcohol problems to problems caused for patients by alcohol. This is less stigmatising and provides role legitimacy for pharmacists to address alcohol clinically in medication reviews, thus providing one element in the formation of a new prevention paradigm. This approach invites further innovations tailored to other healthcare professional roles. [Abstract copyright: © 2023. The Author(s).
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