166 research outputs found

    Quantitative risk assessment of human salmonellosis from the consumption of typical pork products in the Veneto region of Italy

    Get PDF
    ARSIS is a pilot scheme commissioned by the Veneto Region aimed at evaluating the risk of salmonellosis for Veneto region mhabitants due to the consumption of \u27insaccati\u27, typical pork sausages. The quantitative nsk assessment (QRA) approach was used to assess the risk of human salmonellosis and to est1mate the number of cases in a year among Veneto inhabitants, divided into sex and age classes

    Influence of Bioenergy Crop Production and Climate Change on Ecosystem Services

    Full text link
    Land use change can significantly affect the provision of ecosystem services and the effects could be exacerbated by projected climate change. We quantify ecosystem services of bioenergy‐based land use change and estimate the potential changes of ecosystem services due to climate change projections. We considered 17 bioenergy‐based scenarios with Miscanthus, switchgrass, and corn stover as candidate bioenergy feedstock. Soil and Water Assessment Tool simulations of biomass/grain yield, hydrology, and water quality were used to quantify ecosystem services freshwater provision (FWPI), food (FPI) and fuel provision, erosion regulation (ERI), and flood regulation (FRI). Nine climate projections from Coupled Model Intercomparison Project phase‐3 were used to quantify the potential climate change variability. Overall, ecosystem services of heavily row cropped Wildcat Creek watershed were lower than St. Joseph River watershed which had more forested and perennial pasture lands. The provision of ecosystem services for both study watersheds were improved with bioenergy production scenarios. Miscanthus in marginal lands of Wildcat Creek (9% of total area) increased FWPI by 27% and ERI by 14% and decreased FPI by 12% from the baseline. For St. Joseph watershed, Miscanthus in marginal lands (18% of total area) improved FWPI by 87% and ERI by 23% while decreasing FPI by 46%. The relative impacts of land use change were considerably larger than climate change impacts in this paper. Editor’s note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140015/1/jawr12591_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/140015/2/jawr12591.pd

    Energy dispersive-EXAFS of Pd nucleation at a liquid/liquid interface

    Get PDF
    Energy dispersive extended X-ray absorption fine structure (EDE) has been applied to Pd nanoparticle nucleation at a liquid/liquid interface under control over the interfacial potential and thereby the driving force for nucleation. Preliminary analysis focusing on Pd K edge-step height determination shows that under supersaturated conditions the concentration of Pd near the interface fluctuate over a period of several hours, likely due to the continuous formation and dissolution of sub-critical nuclei. Open circuit potential measurements conducted ex-situ in a liquid/liquid electrochemical cell support this view, showing that the fluctuations in Pd concentration are also visible as variations in potential across the liquid/liquid interface. By decreasing the interfacial potential through inclusion of a common ion (tetraethylammonium, TEA+) the Pd nanoparticle growth rate could be slowed down, resulting in a smooth nucleation process. Eventually, when the TEA+ ions reached an equilibrium potential, Pd nucleation and particle growth were inhibited

    Molybdenum sputtering film characterization for high gradient accelerating structures

    Full text link
    Technological advancements are strongly required to fulfill the demands of new accelerator devices with the highest accelerating gradients and operation reliability for the future colliders. To this purpose an extensive R&D regarding molybdenum coatings on copper is in progress. In this contribution we describe chemical composition, deposition quality and resistivity properties of different molybdenum coatings obtained via sputtering. The deposited films are thick metallic disorder layers with different resistivity values above and below the molibdenum dioxide reference value. Chemical and electrical properties of these sputtered coatings have been characterized by Rutherford backscattering, XANES and photoemission spectroscopy. We will also present a three cells standing wave section coated by a molybdenum layer ∌\sim 500 nm thick designed to improve the performance of X-Band accelerating systems.Comment: manuscript has been submitted and accepted by Chinese Physics C (2012

    The application of inelastic neutron scattering to investigate iron-based Fischer-Tropsch to olefins catalysis

    Get PDF
    Sasol Ltd., the University of Glasgow and EPSRC [award reference EP/P505534/1.] are thanked for the provision of postgraduate studentship (ALD). The STFC Rutherford Appleton Laboratory is thanked for access to neutron beam facilities [RB 1520269/1610413]. Diamond Light Source is thanked for time on B18 beamline through the Catalysis Hub BAG application (SP15151 and rapid access beamtime SP18431). The Royal Society is thanked for the provision of an Industry Fellowship (PBW).The technique of inelastic neutron scattering (INS) is used to investigate how hydrogen is partitioned within a series of Na and S promoted iron-based Fischer-Tropsch-to-olefin catalysts. Two reaction test regimes are examined. First, reaction testing at elevated temperature and pressure demonstrate how Na/S additions enhance short chain olefin selectivity and reduce methane formation under industrially relevant reaction conditions. For a fixed level of Na incorporation (2000 ppm), sulfur concentrations of ≀ 100 ppm result in only a modest improvement in olefin selectivity. However, for sulfur values of ≄ 100 ppm there is a noticeable and systematic increase in C2-C4 olefin selectivity; rising from ∌30.0 % to 35.2% at 250 ppm. Second, using ambient pressure CO hydrogenation as a test reaction in INS and micro-reactor configurations, catalyst samples are further analysed by TPR, TPO, XRD and S K-edge XANES. INS shows the formation of a hydrocarbonaceous overlayer to be significantly attenuated by the presence of the promoters, with increasing S levels significantly reducing the intensity of the sp2 and sp3 hybridised Îœ(C-H) modes of the overlayer, albeit to differing degrees. A probable role for how this combination of promoters is perturbing the form of the hydrocarbonaceous overlayer to subsequently moderate the product distribution is considered.Publisher PDFPeer reviewe

    NEOSTEL: the telescope detail design program for the ESA optical ground network dedicated to NEO discovery and tracking

    Get PDF
    The Fly-Eye architecture applied for a Space Debris and NEO Surveillance and Tracking optical telescope has been originally proposed by CGS and further refined in the framework of the Space Situational Awareness (SSA) Preparatory Program studies. The high level architecture of a Telescope based on the Fly-Eye concept has been defined in the TELAD Study. Following TELAD conceptual design, the activities of NEOSTEL aim now at generating the Detailed Design of a NEO Survey Telescope based on the Fly-Eye concept. All components of the telescope are designed at detailed level to satisfy the specific requirements for the Survey and Follow Up of the Near Earth Objects. The NEO Survey Telescope detailed design generated under this Program will be directly utilized for the manufacturing of the first prototype, planned to be launched by the SSA Program in the second half of 2015. In addition, the result of the Detailed Design will produce the documentation necessary to prepare the future site that will host the NEO Survey Telescope prototype as well as the high level architecture of the data processing SW that will be required at the telescope site. The product of the prototypation activity will then constitute a full Italian key Optical Core Technology, dedicated to the NEO thematic but also extendable to the SST Segment, therefore offering possibility of application both at Civil and at Institutional level. Furthermore the Fly-Eye Telescope Technology can actively collaborate with a dedicated Space Segment, opening the way to a complete and autonomous EU System

    Solid-phase phosphorus speciation in Saharan Bodélé depression dusts and source sediments

    Get PDF
    Phosphorus (P) is one of the most important limiting nutrients for the growth of oceanic phytoplankton and terrestrial ecosystems, which in turn contributes to CO2 sequestration. The solid-phase speciation of P will influence its solubility and hence its availability to such ecosystems. This study reports on the results of X-ray diffraction, electron microprobe chemical analysis and X-ray mapping, chemical extractions and X-ray absorption near-edge spectroscopy analysis carried out to determine the solid-phase speciation of P in dusts and their source sediments from the Saharan BodĂ©lĂ© Depression, the world’s largest single source of dust. Chemical extraction data suggest that the BodĂ©lĂ© dusts contain 28 to 60% (mean 49%) P sorbed to, or co-precipitated with Fe (hydr)oxides, < 10% organic P, 21-50% (mean 32%) detrital apatite P, and 10-22% (mean 15%) authigenic-biogenic apatite P. This is confirmed by the other analyses, which also suggest that the authigenic-biogenic apatite P is likely fish bone and scale, and that this might form a larger proportion of the apatite pool (33 +/− 22%) than given by the extraction data. This is the first-ever report of fish material in aeolian dust, and it is significant because P derived from fish bone and scale is relatively soluble and is often used as a soil fertilizer. Therefore, the fish-P will likely be the most readily form of BodĂ©lĂ© P consumed during soil weathering and atmospheric processing, but given time and acid dissolution, the detrital apatite, Fe-P and organic-P will also be made available. The BodĂ©lĂ© dust input of P to global ecosystems will only have a limited life, however, because its major source materials, diatomite in the BodĂ©lĂ© Depression, undergo persistent deflation and have a finite thickness

    Conversion of glucose to fructose over Sn and Ga-doped zeolite Y in methanol and water media

    Get PDF
    In this study, we use zeolite Y as a support for the synthesis of Sn and Ga doped zeolites aimed at the isomerization of glucose to fructose. Though these materials are inactive in water, they are active in methanol and we could ascertain a reaction pathway involving a hydride shift for the interconversion of glucose to fructose and mannose, and a BrĂžnsted acid pathway with the formation of a methyl fructoside intermediate and its hydrolysis to fructose if water was added afterwards. By using characterizations comprising: chemisorption, XPS, XRD, HAADF-STEM and EXAFS; it was possible to demonstrate that a straightforward impregnation protocol for the preparation of our catalysts, led to Sn/Y mainly consisting of small SnO2 clusters on the external surface of the zeolite, whereas Ga/Y consisting of highly dispersed Ga species mostly inside the zeolite pores; and a catalytic activity that appears to be dominated by BrĂžnsted acid sites

    Identification and manipulation of dynamic active site deficiency-induced competing reactions in electrocatalytic oxidation processes

    Get PDF
    Electrocatalytic organic compound oxidation reactions (OCORs) have been intensively studied for energy and environmentally benign applications. However, relatively little effort has been devoted to developing a fundamental understanding of OCORs, including the detailed competition with side reactions and activity limitations, thus inhibiting the rational design of high-performance electrocatalysts. Herein, by taking the NiWO4-catalysed urea oxidation reaction (UOR) in aqueous media as an example, the competition between the OCOR and the oxygen evolution reaction (OER) within a wide potential range is examined. It is shown that the root of the competition can be ascribed to insufficient surface concentration of dynamic Ni3+, an active site shared by both the UOR and OER. A similar phenomenon is observed in other OCOR electrocatalysts and systems. To address the issue, a “controllable reconstruction of pseudo-crystalline bimetal oxides” design strategy is proposed to maximise the dynamic Ni3+ population and manipulate the competition between the UOR and the OER. The optimised electrocatalyst delivers best-in-class performance and an ∌10-fold increase in current density at 1.6 V versus the reversible hydrogen electrode for alkaline urea electrolysis compared to those of the pristine materials
    • 

    corecore