444 research outputs found

    From working in the wheat field to managing wheat: women innovators in Nepal

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    This article presents research conducted in Nepal’s Terai plains in 2014-15 showing that women are innovating in wheat to the extent that wheat farming is experiencing a shift from feminization of agricultural labor towards women taking control over decision making. Processes accounting for this include male out-migration, non-governmental organizations working on promoting women’s equality that has developed women’s confidence, individual support from extension agents, and strong cooperation between women to foster each other’s “innovation journeys.

    Controlling palladium particle size and dispersion as a function of loading by chemical vapour impregnation: an investigation using propane total oxidation as a model reaction

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    A series of Pd/Al2O3 catalysts with metal weight loadings of 1.0 wt%, 2.5 wt%, and 5.0 wt% were synthesised by chemical vapour impregnation (CVI) and used for the total oxidation of propane. All the catalysts were highly active for propane total oxidation. Extensive characterisation showed essentially identical catalyst structural and chemical characteristics, with consistent nanoparticle size, dispersion, and metal oxidation state regardless of metal loading. The major difference between catalysts was the number of surface palladium sites which scaled directly with metal loading. Turnover frequency calculations showed that the intrinsic activity of each catalyst is the same, with conversion scaling with the number of active sites. The number of active sites was normalised experimentally with catalyst performance proving to be identical regardless of weight loading. This study shows that CVI is a technique that can produce active catalysts with high levels of control and consistency of active metal nanoparticles as a function of loading. The same level of control over dispersion and activity was not achieved when catalysts were prepared by conventional aqueous impregnation. The fundamental understanding of CVI is important for the design of highly active catalysts, which is exemplified for propane total oxidation, but has wider significance for other applications of supported metal catalysts

    Characterisation of preproendothelin-1 derived peptides identifies Endothelin-Like Domain Peptide as a modulator of Endothelin-1

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    These studies were supported by the Medical Research Council (UK) (Grant G0801509), Community Fund of the National Lottery Charities Board, William Harvey Research Foundation and British Cardiac Research Trust. The LC-MS/MS facility was supported by Barts and the London Charity (297/2249)

    Working towards an engagement turn to agricultural research in the Tonle Sap Biosphere,Cambodia

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    A new generation of agricultural research programs are embracing use of participation as a vehicle for achieving greater impact and supporting transformative change in complex social-ecological systems. In this paper, we share learning from use of participatory action research in the Tonle Sap biosphere in Cambodia, as the main implementing methodology within a large multi-partner agricultural research program. We describe the program’s espoused approach to applying participatory methodologies focusing on co-ownership, equity and reflexivity with stakeholders throughout the research process. We then reflect upon our practice as we pursued initiatives to support increased income and nutrition outcomes for the poorest people in a diverse aquatic agricultural system characterized by inequality. We discuss the challenges and early successes of the process and share three enabling conditions that support a shift towards quality of participation in agricultural research: (1) focusing at the outset on a strengthsbased mind-set, (2) staging a critical stance to progressively build equity in process and outcomes, and (3) institutionalizing reflexivity to facilitate ongoing learning

    Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

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    Enhancing the understanding of the glycerol to lactic acid reaction mechanism over AuPt/TiO2 under alkaline conditions

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    The oxidation of glycerol under alkaline conditions in the presence of a heterogeneous catalyst can be tailored to the formation of lactic acid, an important commodity chemical. Despite recent advances in this area, the mechanism for its formation is still a subject of contention. In this study, we use a model 1 wt. % AuPt/TiO2 catalyst to probe this mechanism by conducting a series of isotopic labeling experiments with 1,3-13C glycerol. Optimization of the reaction conditions was first conducted to ensure high selectivity to lactic acid in the isotopic labeling experiments. Selectivity to lactic acid increased with temperature and concentration of NaOH, but increasing the O2 pressure appeared to influence only the rate of reaction. Using 1,3-13C glycerol, we demonstrate that conversion of pyruvaldehyde to lactic acid proceeds via a base-promoted 1,2-hydride shift. There was no evidence to suggest that this occurs via a 2,1-methide shift under the conditions used in this study

    Gas phase clycerol valorization over ceria nanostructures with well-defined morphologies

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    Glycerol solutions were vaporized and reacted over ceria catalysts with different morphologies to investigate the relationship of product distribution to the surface facets exposed, particularly, the yield of bio-renewable methanol. Ceria was prepared with cubic, rodlike, and polyhedral morphologies via hydrothermal synthesis by altering the concentration of the precipitating agent or synthesis temperature. Glycerol conversion was found to be low over the ceria with a cubic morphology, and this was ascribed to both a low surface area and relatively high acidity. Density functional theory calculations also showed that the (100) surface is likely to be hydroxylated under reaction conditions which could limit the availability of basic sites. Methanol space-time-yields over the polyhedral ceria samples were more than four times that for the cubic material at 400 °C, where 201 g of methanol was produced per hour per kilogram of the catalyst. Under comparable glycerol conversions, we show that the rodlike and polyhedral catalysts produce a major intermediate to methanol, hydroxyacetone (HA), with a selectivity of ca. 45%, but that over the cubic sample, this was found to be 15%. This equates to a 13-fold increase in the space-time-yield of HA over the polyhedral samples compared to the cubes at 320 °C. The implications of this difference are discussed with respect to the reaction mechanism, suggesting that a different mechanism dominates over the cubic catalysts to that for rodlike and polyhedral catalysts. The strong association between exposed surface facets of ceria to high methanol yields is an important consideration for future catalyst design in this area
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