465 research outputs found
Farmersâ Perceptions and Willingness to Pay for Metarhizium-based Biopesticide to Control Cotton Bollworms in Benin (West Africa)
The study assesses farmersâ perceptions and willingness to pay for a biopesticide developed from Metarhizium anisopliae a fungi. A sample of 400 conventional and organic cotton producers was randomly selected in cotton producing zones in Benin and interviewed for their perceptions on the efficacy of the biopesticide and the likely prices they are willing to pay for the product to control a major pest like Helicoverpa armigera or cotton bollworm causing substantial crop losses. An econometric model (Logit) is used to identify factors highly likely to affect farmerâs willingness to purchase the product. The results show that Helicoverpa armigera or cotton bollworm is perceived by farmers as the most severe pest with losses reaching up to 100%. Farmers attribute the current pest intensity to a number of factors including ineffectiveness of chemical pesticides, delay in access to input mainly fertilizers and the development of refuge host plants for cotton pests. The results also show that most cotton producers and their households members are exposed to chemical insecticides without adequate protection devices during the pest control sprays. Both organic and conventional cotton producers have expressed a significant interest in the use of Metarhizium to control Helicoverpa on cotton. Both types of farmers willing to pay more for any pest control product that would improve cotton product quality for higher cotton price. Three variables influencing farmersâ willing to pay for biopesticides from Metarhizium were efficacy, agro-ecological zone and broad spectrum.Biopesticides, Cotton bollworms, farmers survey, Benin, Agricultural and Food Policy, Community/Rural/Urban Development, Demand and Price Analysis, Farm Management, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, International Relations/Trade, Marketing, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,
Restructuring during pretreatment of platinum/alumina for enantioselective hydrogenation
The influence of reductive and oxidative heat treatment on the enantioselectivity of chirally modified Pt/alumina has been reinvestigated, using the hydrogenation of ketopantolactone as a test reaction. Enhancement in ee by 39-49% has been observed after treatment in hydrogen at 250-600°C, as compared to untreated or preoxidized catalysts. The changes in ee after reductive and oxidative treatments are reversible, and always the final treatment is decisive. A HRTEM study indicates that adsorbateâinduced restructuring of Pt crystallites during hydrogen treatment at elevated temperature can play a role in the selectivity improvement, but the changes are superimposed by the strong structureâdirecting effect of the alumina support. The possible contribution of other effects (complete reduction of Pt n+ surface species, removal of impurities, or change of Pt particle size) could be exclude
Carbon-Supported KCoMoS2 for Alcohol Synthesis from Synthesis Gas
KCoMoS2 was supported on various carbon support materials to study the support effect on synthesis gas conversion. Next to two activated carbons with high micropore volume, a traditional alumina (Îł-Al2O3) support and its carbon coated form (CCA) were studied for comparison. Coating alumina with carbon increases the selectivity to alcohols, but the AC-supported catalysts show even higher alcohol selectivities and yields, especially at higher temperatures where the conversions over the AC-supported catalysts increase more than those over the Îł-Al2O3-based catalysts. Increasing acidity leads to decreased CO conversion yield of alcohols. The two activated-carbon-supported catalysts give the highest yield of ethanol at the highest conversion studied, which seems to be due to increased KCoMoS2 stacking and possibly to the presence of micropores and low amount of mesopores
Patterns and drivers of plant diversity across Australia
Biodiversity analyses across continental extents are important in providing comprehensive information on patterns and likely drivers of diversity. For vascular plants in Australia, community-level diversity analyses have been restricted by the lack of a consistent plot-based survey dataset across the continent. To overcome these challenges, we collated and harmonised plot-based vegetation survey data from the major data sources across Australia and used them as the basis for modelling species richness (α-diversity) and community compositional dissimilarity (ÎČ-diversity), standardised to 400 m2, with the aim of mapping diversity patterns and identifying potential environmental drivers. The harmonised Australian vegetation plot (HAVPlot) dataset includes 219 552 plots, of which we used 115 083 to analyse plant diversity. Models of species richness and compositional dissimilarity both explained approximately one-third of the variation in plant diversity across Australia (D2 = 33.0% and 32.7%, respectively). The strongest environmental predictors for both aspects of diversity were a combination of temperature and precipitation, with soil texture and topographic heterogeneity also important. The fine-resolution (â 90 m) spatial predictions of species richness and compositional dissimilarity identify areas expected to be of particular importance for plant diversity, including south-western Australia, rainforests of eastern Australia and the Australian Alps. Arid areas of central and western Australia are predicted to support assemblages that are less speciose or unique; however, these areas are most in need of additional survey data to fill the spatial, environmental and taxonomic gaps in the HAVPlot dataset. The harmonised data and model predictions presented here provide new insight into plant diversity patterns across Australia, enabling a wide variety of future research, such as exploring changes in species abundances, linking compositional patterns to functional traits or undertaking conservation assessments for selected components of the flora
In situ studies of NO reduction by H-2 over Pt using surface X-ray diffraction and transmission electron microscopy
Feasibility of optical waveguide immunosensors for pesticide detection: physical aspects
In situ studies of NO reduction by H-2 over Pt using surface X-ray diffraction and transmission electron microscopy
In situ studies of NO reduction by H-2 over Pt using surface X-ray diffraction and transmission electron microscopy
<i>In situ</i> studies of NO reduction by H<sub>2</sub> over Pt using surface X-ray diffraction and transmission electron microscopy
In situ studies of NO reduction by H-2 over Pt using surface X-ray diffraction and transmission electron microscopy
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