519 research outputs found

    Modeling and Simulation of Low Temperature Activation Processes

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    A method for simulating dopant activation at low temperatures is proposed and tested, with a proof of concept showing the expected behavior implemented

    Simultaneous CH planar laser-induced fluorescence and particle imaging velocimetry in turbulent flames

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77055/1/AIAA-1998-151-822.pd

    The effect of fuel sprays on emissions from a gas turbine combustor

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76889/1/AIAA-1979-1321.pd

    The study of the turbulent burning velocity by imaging the wrinkled flame surface

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76129/1/AIAA-2002-482-348.pd

    Modeling an Active and Passive Thermal Protection System for a Hypersonic Vehicle

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143043/1/6.2017-0118.pd

    The strain exerted by a vortex on a flame - Determined from velocityfield images

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77209/1/AIAA-1993-362-453.pd

    Parallel fuel injection from the base of an extended strut into supersonic flow

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76778/1/AIAA-1994-711-873.pd

    Characteristics of Cavity-Stabilized Flames in a Supersonic Flow

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77050/1/AIAA-15095-553.pd

    Deposition of mercury in forests across a montane elevation gradient: Elevational and seasonal patterns in methylmercury inputs and production

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    Global mercury contamination largely results from direct primary atmospheric and secondary legacy emissions, which can be deposited to ecosystems, converted to methylmercury, and bioaccumulated along food chains. We examined organic horizon soil samples collected across an elevational gradient on Whiteface Mountain in the Adirondack region of New York State, USA to determine spatial patterns in methylmercury concentrations across a forested montane landscape. We found that soil methylmercury concentrations were highest in the midelevation coniferous zone (0.39 ± 0.07 ng/g) compared to the higher elevation alpine zone (0.28 ± 0.04 ng/g) and particularly the lower elevation deciduous zone (0.17 ± 0.02 ng/g), while the percent of total mercury as methylmercury in soils decreased with elevation. We also found a seasonal pattern in soil methylmercury concentrations, with peak methylmercury values occurring in July. Given elevational patterns in temperature and bioavailable total mercury (derived from mineralization of soil organic matter), soil methylmercury concentrations appear to be driven by soil processing of ionic Hg, as opposed to atmospheric deposition of methylmercury. These methylmercury results are consistent with spatial patterns of mercury concentrations in songbird species observed from other studies, suggesting that future declines in mercury emissions could be important for reducing exposure of mercury to montane avian species.Key PointsTotal mercury and methylmercury concentrations and fluxes are examined across an elevational gradient on an Adirondack, New York mountainMethylmercury concentrations across the elevational gradient are greatest in midelevation coniferous zonesSoil methylmercury concentrations are driven by the internal processing of mercury, rather than external inputs of methylmercuryPlain Language SummaryOnce mercury is emitted into the atmosphere by anthropogenic sources, it can be deposited onto the Earth’s surface. This mercury can then be converted to its toxic form of methylmercury by microbes in the soil and can accumulate in birds, altering physiology, behavior, and reproduction. We examined soils from Whiteface Mountain in the Adirondack region of New York State, USA to determine patterns in the production of methylmercury. We found that methylmercury in soils was highest in the mid‐elevation coniferous forests of the mountain and that the concentration appeared to be driven by soil microbes rather than direct deposition of mercury from the atmosphere. The finding of peak methylmercury at mid‐elevations was consistent with previous studies showing peak bird mercury concentrations at the same elevation. Thus, reductions in methylmercury concentrations in these forests is important to reducing bird mercury concentrations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138300/1/jgrg20832_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138300/2/jgrg20832-sup-0001-2016JG003721-SI.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138300/3/jgrg20832.pd
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