1,352 research outputs found

    Ultra high bypass Nacelle aerodynamics inlet flow-through high angle of attack distortion test

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    A flow-through inlet test program was conducted to evaluate inlet test methods and determine the impact of the fan on inlet separation when operating at large angles of attack. A total of 16 model configurations of approximately 1/6 scale were tested. A comparison of these flow-through results with powered data indicates the presence of the fan increased separation operation 3 degrees to 4 degrees over the flow through inlet. Rods and screens located at the fan face station, that redistribute the flow, achieved simulation of the powered-fan results for separation angle of attack. Concepts to reduce inlet distortion and increase angle of attack capability were also evaluated. Vortex generators located on the inlet surface increased inlet angle of attack capability up to 2 degrees and reduced inlet distortion in the separated region. Finally, a method of simulating the fan/inlet aerodynamic interaction using blockage sizing method has been defined. With this method, a static blockage device used with a flow-through model will approximate the same inlet onset of separation angle of attack and distortion pattern that would be obtained with an inlet model containing a powered fan

    Laboratory-Scale Melter for Determination of Melting Rate of Waste Glass Feeds

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    The purpose of this study was to develop the laboratory-scale melter (LSM) as a quick and inexpensive method to determine the processing rate of various waste glass slurry feeds. The LSM uses a 3 or 4 in. diameter-fused quartz crucible with feed and off-gas ports on top. This LSM setup allows cold-cap formation above the molten glass to be directly monitored to obtain a steady-state melting rate of the waste glass feeds. The melting rate data from extensive scaled-melter tests with Hanford Site high-level wastes performed for the Hanford Tank Waste Treatment and Immobilization Plant have been compiled. Preliminary empirical model that expresses the melting rate as a function of bubbling rate and glass yield were developed from the compiled database. The two waste glass feeds with most melter run data were selected for detailed evaluation and model development and for the LSM tests so the melting rates obtained from LSM tests can be compared with those from scaled-melter tests. The present LSM results suggest the LSM setup can be used to determine the glass production rates for the development of new glass compositions or feed makeups that are designed to increase the processing rate of the slurry feeds

    Biophysical consequences of a relaxing Beaufort Gyre

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zhang, J., Spitz, Y. H., Steele, M., Ashjian, C., Campbell, R., & Schweiger, A. Biophysical consequences of a relaxing Beaufort Gyre. Geophysical Research Letters, 47(2), (2020): e2019GL085990, doi:10.1029/2019GL085990.A biophysical model shows that Beaufort Gyre (BG) intensification in 2004–2016 is followed by relaxation in 2017–2018, based on a BG variability index. BG intensification leads to enhanced downwelling in the central Canada Basin (CCB) and upwelling along the coast. In the CCB, enhanced downwelling reduces nutrients, thus lowering primary productivity (PP) and plankton biomass. Enhanced upwelling along the coast and in parts of the Chukchi shelf/slope increases nutrients, leading to elevated PP/biomass in the Pacific Arctic Ocean (PAO) outside of the CCB. The overall PAO PP/biomass is dominated by the shelf/slope response and thus increases during BG intensification. As the BG relaxes in 2017–2018, these processes largely reverse, with increasing PP/biomass in the CCB and decreasing PP/biomass in most of the shelf/slope regions. Because the shelf/slope regions are much more productive than the CCB, BG relaxation has the tendency to reduce the overall production in the PAO.This work is funded by the NASA Cryosphere Program (NNX15AG68G and NNX17AD27G), the NSF Office of Polar Programs (PLR‐1416920, PLR‐1603259, PLR‐1603266, OPP‐1751363, PLR‐1602521, and PLR‐1503298), the NOAA Climate Program Office (NA15OAR4310170 and NA15OAR4320063AM170), and ONR (N00014‐17‐1‐2545). We thank Drs. Benjamin Rabe and Edward Doddridge for their constructive comments and Kay Runciman for graphics support. CFS reanalysis data used for model forcing are available online (https://www.ncdc.noaa.gov/data‐access/model‐data/model‐datasets/climate‐forecast‐system‐version2‐cfsv2). Model results are in https://pscfiles.apl.uw.edu/zhang/BIOMAS168x180/ website

    Initial Laboratory-Scale Melter Test Results for Combined Fission Product Waste

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    This report describes the methods and results used to vitrify a baseline glass, CSLNTM-C-2.5 in support of the AFCI (Advanced Fuel Cycle Initiative) using a Quartz Crucible Scale Melter at the Pacific Northwest National Laboratory. Document number AFCI-WAST-PMO-MI-DV-2009-000184

    Fire Safety Tests for Cesium-Loaded Spherical Resorcinol Formaldehyde Resin: Data Summary Report

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    A draft safety evaluation of the scenario for spherical resorcinol formaldehyde (SRF) resin fire inside the ion exchange column was performed by the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Fire Safety organization. The result of this draft evaluation suggested a potential change of the fire safety classification for the Cesium Ion Exchange Process System (CXP) emergency elution vessels, equipment, and piping. To resolve this question, the fire properties of the SRF resin were measured by Southwest Research Institute (SwRI) through a subcontract managed by Pacific Northwest National Laboratory (PNNL). The results of initial fire safety tests on the SRF resin were documented in a previous report (WTP-RPT-218). The present report summarizes the results of additional tests performed by SwRI on the cesium-loaded SRF resin. The efforts by PNNL were limited to summarizing the test results provided by SwRI into one consolidated data report. The as-received SwRI report is attached to this report in the Appendix A. Where applicable, the precision and bias of each test method, as given by each American Society for Testing and Materials (ASTM) standard procedure, are included and compared with the SwRI test results of the cesium-loaded SRF resin

    Gleenglass Swarf Research

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    Objective: John Sauer, Gleenglass principal, asked for research into innovative uses for a reclaimed glass slurry, also referred to as swarf. Through our research we were to determine a product and a market that could be manufactured using this fully recycled glass swarf. Background: Mr. Sauer receives the swarf from major glass manufacturers as a fine powder glass suspended in an organic dispersant and water. The swarf is produced through an industrial glass cutting process that results in the glass powder dispersed in water and recyclable glass disks; both are used in the project. Mr. Sauer's swarf studio testing has yet to produce any product with a value great enough to justify processing the swarf. Many of these limitations were believed to be due to the unknown composition and characteristics of the swarf as well as the limited lab testing ability of Mr. Sauer in his studio space. Deliverables: 1. The valuable characteristics of the swarf. 2. Products that can be produced with the swarf. 3. Market for developed products. 4. Capital investment needed to create developed product. 5. Any other applications of the swarf that were outside the scope of residential and commercial building material for use in future DOE grant proposals to the glass manufacturing facilities. 6. Additives that could change the color of the final piece to white, gray, or green

    The STOP COVID 2 study: Fluvoxamine vs placebo for outpatients with symptomatic COVID-19, a fully remote randomized controlled trial

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    BACKGROUND: Prior randomized clinical trials have reported benefit of fluvoxamine ≥200 mg/d vs placebo for patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: This randomized, double-blind, placebo-controlled, fully remote multisite clinical trial evaluated whether fluvoxamine prevents clinical deterioration in higher-risk outpatients with acute coronavirus disease 2019 (COVID-19). Between December 2020 and May 2021, nonhospitalized US and Canadian participants with confirmed symptomatic infection received fluvoxamine (50 mg on day 1, 100 mg twice daily thereafter) or placebo for 15 days. The primary modified intent-to-treat (mITT) population included participants who started the intervention within 7 days of symptom onset with a baseline oxygen saturation ≥92%. The primary outcome was clinical deterioration within 15 days of randomization, defined as having both (1) shortness of breath (severity ≥4 on a 0-10 scale or requiring hospitalization) RESULTS: A total of 547 participants were randomized and met mITT criteria (n = 272 fluvoxamine, n = 275 placebo). The Data Safety Monitoring Board recommended stopping early for futility related to lower-than-predicted event rates and declining accrual concurrent with vaccine availability in the United States and Canada. Clinical deterioration occurred in 13 (4.8%) participants in the fluvoxamine group and 15 (5.5%) participants in the placebo group (absolute difference at day 15, 0.68%; 95% CI, -3.0% to 4.4%; log-rank CONCLUSIONS: This trial did not find fluvoxamine efficacious in preventing clinical deterioration in unvaccinated outpatients with symptomatic COVID-19. It was stopped early and underpowered due to low primary outcome rates. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier: NCT04668950

    Coupling spectral and resource-use complementarity in experimental grassland and forest communites

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    Reflectance spectra provide integrative measures of plant phenotypes by capturing chemical, morphological, anatomical and architectural trait information. Here, we investigate the linkages between plant spectral variation, and spectral and resource-use complementarity that contribute to ecosystem productivity. In both a forest and prairie grassland diversity experiment, we delineated n-dimensional hypervolumes using wavelength bands of reflectance spectra to test the association between the spectral space occupied by individual plants and their growth, as well as between the spectral space occupied by plant communities and ecosystem productivity. We show that the spectral space occupied by individuals increased with their growth, and the spectral space occupied by plant communities increased with ecosystem productivity. Furthermore, ecosystem productivity was better explained by inter-individual spectral complementarity than by the large spectral space occupied by productive individuals. Our results indicate that spectral hypervolumes of plants can reflect ecological strategies that shape community composition and ecosystem function, and that spectral complementarity can reveal resource-use complementarity
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