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Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Emissions From Miombo Woodland And Dambo Grassland Savanna Fires, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, Donald R. Blake, Song Gao, Thomas W. Kirschsetter
Emissions From Miombo Woodland And Dambo Grassland Savanna Fires, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, Donald R. Blake, Song Gao, Thomas W. Kirschsetter
Chemistry and Biochemistry Faculty Publications
[1] Airborne measurements of trace gases and particles over and downwind of two prescribed savanna fires in Zambia are described. The measurements include profiles through the smoke plumes of condensation nucleus concentrations and normalized excess mixing ratios of particles and gases, emission factors for 42 trace gases and seven particulate species, and vertical profiles of ambient conditions. The fires were ignited in plots of miombo woodland savanna, the most prevalent savanna type in southern Africa, and dambo grassland savanna, an important enclave of miombo woodland ecosystems. Emission factors for the two fires are combined with measurements of fuel loading, combustion …
Thickness Dependence Of Magneto-Transport In Cu-Co Granular Thin Films, Jian Qing Wang, Ngocnga Dao, Ham H. Kim, Scott L. Whittenburg
Thickness Dependence Of Magneto-Transport In Cu-Co Granular Thin Films, Jian Qing Wang, Ngocnga Dao, Ham H. Kim, Scott L. Whittenburg
Chemistry and Biochemistry Faculty Publications
This work explores the thickness dependence of magneto-transport properties in granular thin films with different thickness. These results are compared with silver-based film series studied earlier. It was observed that the thickness dependence of the GMReffect was sensitive to the surface chemistry of the films. The extraordinary Hall effect (EHE) in these films was measured and found to be different from the Ag-based system. In the Cu-based system, the EHE is a weak function of film thickness over the range studied. When the variation of the spontaneous magnetization is taken into account the effective EHE has a universal thickness dependence
Heterogeneous Chemistry Involving Methanol In Tropospheric Clouds, A. Tabazadeh, Robert J. Yokelson, H. B. Singh, Peter V. Hobbs, J. H. Crawford, L. T. Iraci
Heterogeneous Chemistry Involving Methanol In Tropospheric Clouds, A. Tabazadeh, Robert J. Yokelson, H. B. Singh, Peter V. Hobbs, J. H. Crawford, L. T. Iraci
Chemistry and Biochemistry Faculty Publications
In this report we analyze airborne measurements to suggest that methanol in biomass burning smoke is lost heterogeneously in clouds. When a smoke plume intersected a cumulus cloud during the SAFARI 2000 field project, the observed methanol gas phase concentration rapidly declined. Current understanding of gas and aqueous phase chemistry cannot explain the loss of methanol documented by these measurements. Two plausible heterogeneous reactions are proposed to explain the observed simultaneous loss and production of methanol and formaldehyde, respectively. If the rapid heterogeneous processing of methanol, seen in a cloud impacted by smoke, occurs in more pristine clouds, it could …
Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 2. First Intercomparison Of Open-Path Ftir, Ptr-Ms, And Gc-Ms/Fid/Ecd, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wein Min Hao, T. Shirai, Donald R. Blake
Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 2. First Intercomparison Of Open-Path Ftir, Ptr-Ms, And Gc-Ms/Fid/Ecd, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wein Min Hao, T. Shirai, Donald R. Blake
Chemistry and Biochemistry Faculty Publications
No abstract provided.
Vemap Phase 2 Bioclimatic Database. I. Gridded Historical (20th Century) Climate For Modeling Ecosystem Dynamics Across The Conterminous Usa, T. G. F. Kittel, N. A. Rosenbloom, J. A. Royle, C. Daly, W. P. Gibson, H. H. Fisher, P. Thornton, D. N. Yates, C. Kaufman, R. Mckeown, D. Bachelet, D. S. Schimel, Steven W. Running, Vemap2 Participants
Vemap Phase 2 Bioclimatic Database. I. Gridded Historical (20th Century) Climate For Modeling Ecosystem Dynamics Across The Conterminous Usa, T. G. F. Kittel, N. A. Rosenbloom, J. A. Royle, C. Daly, W. P. Gibson, H. H. Fisher, P. Thornton, D. N. Yates, C. Kaufman, R. Mckeown, D. Bachelet, D. S. Schimel, Steven W. Running, Vemap2 Participants
Ecosystem and Conservation Sciences Faculty Publications
Analysis and simulation of biospheric responses to historical forcing require surface climate data that capture those aspects of climate that control ecological processes, including key spatial gradients and modes of temporal variability. We developed a multivariate, gridded historical climate dataset for the conterminous USA as a common input database for the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP), a biogeochemical and dynamic vegetation model intercomparison. The dataset covers the period 1895-1993 on a 0.5° latitude/longitude grid. Climate is represented at both monthly and daily timesteps. Variables are: precipitation, mininimum and maximum temperature, total incident solar radiation, daylight-period irradiance, vapor pressure, and …
Detailed Spatially Distributed Geothermal Heat-Flow Data For Modeling Of Basal Temperatures And Meltwater Production Beneath The Fennoscandian Ice Sheet, Jens-Ove Näslund, Peter Jansson, James L. Fastook, Jesse Johnson, Leif Andersson
Detailed Spatially Distributed Geothermal Heat-Flow Data For Modeling Of Basal Temperatures And Meltwater Production Beneath The Fennoscandian Ice Sheet, Jens-Ove Näslund, Peter Jansson, James L. Fastook, Jesse Johnson, Leif Andersson
Computer Science Faculty Publications
Accurate modeling of ice sheets requires proper information on boundary conditions, including the geothermal heat flow (or heat-flow density (HFD)). Traditionally, one uniform HFD value is adopted for the entire modeled domain. We have calculated a distributed, high-resolution HFD dataset for an approximate core area (Sweden and Finland) of the Scandinavian ice sheet, and imbedded this within lower-resolution data published for surrounding regions. Within the Last Glacial Maximum ice margin, HFD varies with a factor of as much as 2.8 (HFD values ranging between 30 and 83mWm–2), with an average of 49mWm–2. This average value is 17% higher than 42mWm–2, …
Ice Dynamics Preceding Catastrophic Disintegration Of The Floating Part Of Jakobshavn Isbræ, Greenland, Jesse V. Johnson, Paul R. Prescott, Terence J. Hughes
Ice Dynamics Preceding Catastrophic Disintegration Of The Floating Part Of Jakobshavn Isbræ, Greenland, Jesse V. Johnson, Paul R. Prescott, Terence J. Hughes
Computer Science Faculty Publications
The floating terminal of Jakobshavn Isbræ, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam.
Efficient Linkage Discovery By Limited Probing, Robert B. Heckendorn, Alden H. Wright
Efficient Linkage Discovery By Limited Probing, Robert B. Heckendorn, Alden H. Wright
Computer Science Faculty Publications
This paper addresses the problem of discovering the structure of a fitness function from binary strings to the reals under the assumption of bounded epistasis. Two loci (string positions) are epistatically linked if the effect of changing the allele (value) at one locus depends on the allele at the other locus. Similarly, a group of loci are epistatically linked if the effect of changing the allele at one locus depends on the alleles at all other loci of the group. Under the assumption that the size of such groups of loci are bounded, and assuming that the function is given …