1,944 research outputs found

    Crogenic alloy screening Interim report

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    Evaluation of mechanical properties and fracture strength of aluminum alloys and stainless stee

    Determination of low-temperature fatigue properties of structural metal alloys Final report, Jul. 1964 - Aug. 1965

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    Fatigue testing and determination of low temperature properties of structural metal alloys - aluminum alloy, stainless steel, and nickel alloy

    Cryogenic alloy screening Final report

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    Mechanical properties of cryogenically stretched type 301 stainless steel and aluminum alloys 2021-T81 and X7007-T

    The impact of COVID-19 on BAME populations: a systematic review of experiences and perspectives

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    Black, Asian, Minority Ethnic (BAME) populations have been disproportionately affected by COVID-19, having amongst the highest rates of infection and mortality. Additional risk factors for BAME populations include older age and living with poverty and deprivation. Information has emerged, but peer reviewed research and literature examining the experiences and/or perspectives of this most recent of diseases on BAME populations is fragmented and lacks coalescence. This systematic review will therefore bring together and integrate existing and emergent evidence around the experiences and/or perspectives of COVID-19 on BAME populations

    COLLABORATING IN THE CAPTURE LAB: Computer Support for Group Writing

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67328/2/10.1177_108056999005300208.pd

    Effects of elevated CO2 and temperature on phytoplankton community biomass, species composition and photosynthesis during an experimentally induced autumn bloom in the western English Channel

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    The combined effects of elevated pCO2 and temperature were investigated during an experimentally induced autumn phytoplankton bloom in vitro sampled from the western English Channel (WEC). A full factorial 36-day microcosm experiment was conducted under year 2100 predicted temperature (+4.5°C) and pCO2 levels (800μatm). Over the experimental period total phytoplankton biomass was significantly influenced by elevated pCO2. At the end of the experiment, biomass increased 6.5-fold under elevated pCO2 and 4.6-fold under elevated temperature relative to the ambient control. By contrast, the combined influence of elevated pCO2 and temperature had little effect on biomass relative to the control. Throughout the experiment in all treatments and in the control, the phytoplankton community structure shifted from dinoflagellates to nanophytoplankton . At the end of the experiment, under elevated pCO2 nanophytoplankton contributed 90% of community biomass and was dominated by Phaeocystis spp. Under elevated temperature, nanophytoplankton comprised 85% of the community biomass and was dominated by smaller nanoflagellates. In the control, larger nanoflagellates dominated whilst the smallest nanophytoplankton contribution was observed under combined elevated pCO2 and temperature ( ∼ 40%). Under elevated pCO2, temperature and in the control there was a significant decrease in dinoflagellate biomass. Under the combined effects of elevated pCO2 and temperature, dinoflagellate biomass increased and was dominated by the harmful algal bloom (HAB) species, Prorocentrum cordatum. At the end of the experiment, chlorophyll a (Chl a) normalised maximum photosynthetic rates (PBm) increased > 6-fold under elevated pCO2 and > 3-fold under elevated temperature while no effect on PBm was observed when pCO2 and temperature were elevated simultaneously. The results suggest that future increases in temperature and pCO2 simultaneously do not appear to influence coastal phytoplankton productivity but significantly influence community composition during autumn in the WEC

    Accurately constraining velocity information from spectral imaging observations using machine learning techniques

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    Determining accurate plasma Doppler (line-of-sight) velocities from spectroscopic measurements is a challenging endeavour, especially when weak chromospheric absorption lines are often rapidly evolving and, hence, contain multiple spectral components in their constituent line profiles. Here, we present a novel method that employs machine learning techniques to identify the underlying components present within observed spectral lines, before subsequently constraining the constituent profiles through single or multiple Voigt fits. Our method allows active and quiescent components present in spectra to be identified and isolated for subsequent study. Lastly, we employ a Ca II 8542 {\AA} spectral imaging dataset as a proof-of-concept study to benchmark the suitability of our code for extracting two-component atmospheric profiles that are commonly present in sunspot chromospheres. Minimisation tests are employed to validate the reliability of the results, achieving median reduced χ2\chi^2 values equal to 1.03 between the observed and synthesised umbral line profiles.Comment: 23 pages, 8 figures. Improved formatting of abstract and reference

    Cube law, condition factor and weight-length relationships: history, meta-analysis and recommendations

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    This study presents a historical review, a meta-analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta-analysis explores 3929 weight–length relationships of the type W = aLb for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive-allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as Kmean = 100aLb−3. Relative weight Wrm = 100W/(amLbm) can be used for comparing the condition of individuals across populations, where am is the geometric mean of a and bm is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given
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