554 research outputs found

    Fluid Phase Separation (FPS) experiment for flight on a space shuttle Get Away Special (GAS) canister

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    The separation of fluid phases in microgravity environments is of importance to environmental control and life support systems (ECLSS) and materials processing in space. A successful fluid phase separation experiment will demonstrate a proof of concept for the separation technique and add to the knowledge base of material behavior. The phase separation experiment will contain a premixed fluid which will be exposed to a microgravity environment. After the phase separation of the compound has occurred, small samples of each of the species will be taken for analysis on the Earth. By correlating the time of separation and the temperature history of the fluid, it will be possible to characterize the process. The experiment has been integrated into space available on a manifested Get Away Special (GAS) experiment, CONCAP 2, part of the Consortium for Materials Complex Autonomous Payload (CAP) Program, scheduled for STS-42. The design and the production of a fluid phase separation experiment for rapid implementation at low cost is presented

    Using task farming to optimise a street-scale resolution air quality model of the West Midlands (UK)

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    High resolution air quality models combining emissions, chemical processes, dispersion and dynamical treatments are necessary to develop effective policies for clean air in urban environments, but can have high computational demand. We demonstrate the application of task farming to reduce runtime for ADMS-Urban, a quasi-Gaussian plume air dispersion model. The model represents the full range of source types (point, road and grid sources) occurring in an urban area at high resolution. Here, we implement and evaluate the option to automatically split up a large model domain into smaller sub-regions, each of which can then be executed concurrently on multiple cores of a HPC or across a PC network, a technique known as task farming. The approach has been tested for a large model domain covering the West Midlands, UK (902 km2), as part of modelling work in the WM-Air (West Midlands Air Quality Improvement Programme) project. Compared to the measurement data, overall, the model performs well. Air quality maps for annual/subset averages and percentiles are generated. For this air quality modelling application of task farming, the optimisation process has reduced weeks of model execution time to approximately 35 h for a single model configuration of annual calculations

    Mapping urban green infrastructure : a novel landscape-based approach to incorporating land-use and land-cover in the mapping of human-dominated systems

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    Common approaches to mapping green infrastructure in urbanized landscapes invariably focus on measures of land-use or land-cover and associated functional or physical traits. However, such one-dimensional perspectives do not accurately capture the character and complexity of the landscapes in which urban inhabitants live. The new approach presented in this paper demonstrates how open-source, high spatial and temporal resolution data with global coverage can be used to measure and represent the landscape qualities of urban environments. Through going beyond simple metrics of quantity, such as percentage green and blue cover it is now possible to explore the extent to which landscape quality helps to unpick the mixed evidence presented in the literature on the benefits of urban nature to human well-being. Here we present a landscape approach, employing remote sensing, GIS and data reduction techniques, to map urban green infrastructure elements in a large UK city-region. Comparison with existing urban datasets demonstrates considerable improvement in terms of coverage and thematic detail. The characterisation of landscapes, using census tracts as spatial units, and subsequent exploration of associations with social-ecological attributes highlights the further detail which can be uncovered with the approach. For example, eight urban landscape types identified for the case study city exhibited associations with distinct socio-economic conditions accountable not only to quantities but also qualities of green and blue space. The identification of individual landscape features through simultaneous measures of land-use and land cover demonstrated unique and significant associations between the former and indicators of human health and ecological condition. The approach may therefore provide a promising basis for developing further insight into the processes and characteristics which affect human health and wellbeing in urban areas, both in the UK and beyond

    Effects of Inherent Tissue Anisotropy on Measurements Obtained with a Clinical Ultrasonic Imaging System

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    Our overall goal is to develop clinically applicable tissue characterization methods, based on quantitative analyses of backscattered ultrasound, which can differentiate normal from diseased heart segments. In implementing these methods there is a need to compensate for the inherent anisotropic properties of the heart that are exhibited in echocardiographic images. [1–4] Furthermore, quantitative tissue characterization methods may be able to exploit the inherent anisotropy of the myocardium to achieve assessment of cardiac properties.[5–9] The specific aims of this investigation were to measure the spectral properties of backscattered ultrasound using a clinical imaging system and to determine effects of inherent tissue anisotropy on measured spectral properties of backscattered ultrasound

    The HANDE-QMC Project: Open-Source Stochastic Quantum Chemistry from the Ground State Up.

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    Building on the success of Quantum Monte Carlo techniques such as diffusion Monte Carlo, alternative stochastic approaches to solve electronic structure problems have emerged over the past decade. The full configuration interaction quantum Monte Carlo (FCIQMC) method allows one to systematically approach the exact solution of such problems, for cases where very high accuracy is desired. The introduction of FCIQMC has subsequently led to the development of coupled cluster Monte Carlo (CCMC) and density matrix quantum Monte Carlo (DMQMC), allowing stochastic sampling of the coupled cluster wave function and the exact thermal density matrix, respectively. In this Article, we describe the HANDE-QMC code, an open-source implementation of FCIQMC, CCMC and DMQMC, including initiator and semistochastic adaptations. We describe our code and demonstrate its use on three example systems; a molecule (nitric oxide), a model solid (the uniform electron gas), and a real solid (diamond). An illustrative tutorial is also included

    Discovery of a nanodiamond-rich layer in the Greenland ice sheet

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    We report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5!106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 0.1 ka. However, more investigation is needed to confirm this association

    The Vehicle, 1961, Vol. 3 no. 2

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    Vol. 3, No. 2 Table of Contents The Voting CattleLinda Kay Campbellpage 5 But For the Passage of TimeDon Shepardsonpage 14 LoveJon Woodspage 16 Infinite JourneyJames E. Martinpage 19 The Clover ChainRichard W. Blairpage 20 SnowballSusan Daughertypage 24 Sureness Is NeverDon Shepardsonpage 26 ConceptionChristine McCollpage 34 Comedy: Relief and GriefTom McPeakpage 35 The Unspoken WordChristine McCollpage 35 CharmBenjamin Polkpage 36 Screaming SpiderTom McPeakpage 39 Just Once in an Early SpringE.J.B.page 39 HummingbirdPauline B. Smithpage 40 Willow TreesPauline B. Smithpage 40 MaturityChristine McCollpage 41 The New YearLinda Campbellpage 41 The StormMary-Jean Pitratpage 42 Ebony IvoryJean Danenbargerpage 42 The Fireball MailAllen Engelbrightpage 43 ExpectationChristine McCollpage 44 CatastropheChristine McCollpage 44 SophisticationBenjamin Polkpage 45 On Playing BridgeMyrna Jo Handleypage 46 SonnetMignon Stricklandpage 48https://thekeep.eiu.edu/vehicle/1009/thumbnail.jp

    The Vehicle, 1961, Vol. 3 no. 2

    Get PDF
    Vol. 3, No. 2 Table of Contents The Voting CattleLinda Kay Campbellpage 5 But For the Passage of TimeDon Shepardsonpage 14 LoveJon Woodspage 16 Infinite JourneyJames E. Martinpage 19 The Clover ChainRichard W. Blairpage 20 SnowballSusan Daughertypage 24 Sureness Is NeverDon Shepardsonpage 26 ConceptionChristine McCollpage 34 Comedy: Relief and GriefTom McPeakpage 35 The Unspoken WordChristine McCollpage 35 CharmBenjamin Polkpage 36 Screaming SpiderTom McPeakpage 39 Just Once in an Early SpringE.J.B.page 39 HummingbirdPauline B. Smithpage 40 Willow TreesPauline B. Smithpage 40 MaturityChristine McCollpage 41 The New YearLinda Campbellpage 41 The StormMary-Jean Pitratpage 42 Ebony IvoryJean Danenbargerpage 42 The Fireball MailAllen Engelbrightpage 43 ExpectationChristine McCollpage 44 CatastropheChristine McCollpage 44 SophisticationBenjamin Polkpage 45 On Playing BridgeMyrna Jo Handleypage 46 SonnetMignon Stricklandpage 48https://thekeep.eiu.edu/vehicle/1009/thumbnail.jp
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