746 research outputs found

    Variations in Alaska tidewater glacier frontal ablation, 1985–2013

    Get PDF
    Our incomplete knowledge of the proportion of mass loss due to frontal ablation (the sum of ice loss through calving and submarine melt) from tidewater glaciers outside of the Greenland and Antarctic ice sheets has been cited as a major hindrance to accurate predictions of global sea level rise. We present a 28 year record (1985–2013) of frontal ablation for 27 Alaska tidewater glaciers (representing 96% of the total tidewater glacier area in the region), calculated from satellite-derived ice velocities and modeled estimates of glacier ice thickness. We account for cross-sectional ice thickness variation, long-term thickness changes, mass lost between an upstream fluxgate and the terminus, and mass change due to changes in terminus position. The total mean rate of frontal ablation for these 27 glaciers over the period 1985–2013 is 15.11 ± 3.63Gta⁻Âč. Two glaciers, Hubbard and Columbia, account for approximately 50% of these losses. The regional total ablation has decreased at a rate of 0.14Gta⁻Âč over this time period, likely due to the slowing and thinning of many of the glaciers in the study area. Frontal ablation constitutes only ∌4% of the total annual regional ablation, but roughly 20% of net mass loss. Comparing several commonly used approximations in the calculation of frontal ablation, we find that neglecting cross-sectional thickness variations severely underestimates frontal ablation

    Optical extinction due to intrinsic structural variations of photonic crystals

    Full text link
    Unavoidable variations in size and position of the building blocks of photonic crystals cause light scattering and extinction of coherent beams. We present a new model for both 2 and 3-dimensional photonic crystals that relates the extinction length to the magnitude of the variations. The predicted lengths agree well with our new experiments on high-quality opals and inverse opals, and with literature data analyzed by us. As a result, control over photons is limited to distances up to 50 lattice parameters (∌15ÎŒ\sim 15 \mum) in state-of-the-art structures, thereby impeding large-scale applications such as integrated circuits. Conversely, scattering in photonic crystals may lead to novel physics such as Anderson localization and non-classical diffusion.Comment: 10 pages, 3 figures. Changes include: added Lagendijk as author; simplified and generalized the tex

    Grasses as Biofactories: Scoping out the Opportunities

    Get PDF
    Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins. The choice of plant species depends on a multitude of factors and is determined on a case- by-case basis. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming

    Animal waste management

    Get PDF
    "71/1M""Livestock producers have asked for guidelines on animal waste management that will be feasible and enduring. The Missouri Water Pollution Board has been aware of the need for improvements in methods of handling waste from confined feeding operations and for guidelines for producers. Chapter 204 of Missouri Statutes, as amended, gives the Water Pollution Board the responsibility and authority to correct and/or prevent "pollution" of "waters of the state." These terms are defined in the law and discussed briefly in the first section. With these facts in mind, staff engineers of the Water Pollution Board held a series of meetings with staff members of the Extension Division and Department of Agricultural Engineering of the University of Missouri-Columbia to develop guidelines for disposing of waste from confinement feeding operations. This report is a result of their combined efforts. Others assisting with various phases of development of these guidelines included: School of Engineering, University of Missouri-Columbia; State Department of Health, and the Soil Conservation Service. Research data and experience in handling livestock wastes have been used to develop the guidelines for planning, design, construction, and management of alternative systems of livestock waste management. The information and design guidelines herein are intended primarily for the use of personnel in agencies concerned with animal waste management problems." --PrefaceMissouri Water Pollution Board and Extension Division, University of Missouri - Columbia

    Grasses as Biofactories: Scoping out the Opportunities

    Get PDF
    Key points 1. Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins. 2. The choice of plant species depends on a multitude of factors and is determined on a caseby- case basis. 3. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa. 4. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming

    The acheulean handaxe : More like a bird's song than a beatles' tune?

    Get PDF
    © 2016 Wiley Periodicals, Inc. KV is supported by the Netherlands Organization for Scientific Research. MC is supported by the Canada Research Chairs Program, the Social Sciences and Humanities Research of Canada, the Canada Foundation for Innovation, the British Columbia Knowledge Development Fund, and Simon Fraser UniversityPeer reviewedPublisher PD

    Effect of Condensed Tannin in Lotus Corniculatus and Lotus Pedunculatus on Digestion of Rubisco in the Rumen

    Get PDF
    The in vitro precipitation of ribulose-1,5-bisphosphate carboxylase (Rubisco) by condensed tannin (CT) extracted from Lotus corniculatus and Lotus pedunculatus and the effect of these CT on the in vitro rumen degradation of Rubisco was used to compare the reactivity of these CT. The chemical structure of CT from Lotus corniculatus was homogenous with epicatechin stereochemistry and mostly procyanidin units. The CT from Lotus pedunculatus was heterogenous with mostly prodelphinidin units. The amount of CT required to precipitate all the Rubisco when total soluble leaf protein was incubated with CT from Lotus corniculatus and Lotus pedunculatus was similar. Although CT from both species were able to reduce the in vitro degradation of Rubisco, CT from Lotus corniculatus was less effective than CT from Lotus pedunculatus at reducing this degradation

    Superdeformation in 198^{198}Po

    Full text link
    The 174^{174}Yb(29^{29}Si,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in 198^{198}Po. Resulting γ\gamma rays were observed with Gammasphere. A weakly-populated superdeformed band of 10 γ\gamma-ray transitions was found and has been assigned to 198^{198}Po. This is the first observation of a SD band in the A≈190A \approx 190 region in a nucleus with Z>83Z > 83. The J(2){\cal J}^{(2)} of the new band is very similar to those of the yrast SD bands in 194^{194}Hg and 196^{196}Pb. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.Comment: 10 pages, revtex, 2 figs. available on request, submitted to Phys. Rev. C. (Rapid Communications

    Plans for the LIGO-TAMA Joint Search for Gravitational Wave Bursts

    Full text link
    We describe the plans for a joint search for unmodelled gravitational wave bursts being carried out by the LIGO and TAMA collaborations using data collected during February-April 2003. We take a conservative approach to detection, requiring candidate gravitational wave bursts to be seen in coincidence by all four interferometers. We focus on some of the complications of performing this coincidence analysis, in particular the effects of the different alignments and noise spectra of the interferometers.Comment: Proceedings of the 8th Gravitational Wave Data Analysis Workshop, Milwaukee, WI, USA. 10 pages, 3 figures, documentclass ``iopart'

    Spectroscopy of 194^{194}Po

    Get PDF
    Prompt, in-beam γ\gamma rays following the reaction 170^{170}Yb + 142 MeV 28^{28}Si were measured at the ATLAS facility using 10 Compton-suppressed Ge detectors and the Fragment Mass Analyzer. Transitions in 194^{194}Po were identified and placed using γ\gamma-ray singles and coincidence data gated on the mass of the evaporation residues. A level spectrum up to J≈\approx10ℏ\hbar was established. The structure of 194^{194}Po is more collective than that observed in the heavier polonium isotopes and indicates that the structure has started to evolve towards the more collective nature expected for deformed nuclei.Comment: 8 pages, revtex 3.0, 4 figs. available upon reques
    • 

    corecore