183 research outputs found

    Understanding the active sites of boron nitride for CWPO: An experimental and computational approach

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    Hexagonal boron nitride (h-BN) has been explored as a catalyst for degrading persistent organic pollutants in wastewater by Catalytic Wet Peroxide Oxidation (CWPO). Herein, the superior activity of the h-BN on the phenol degradation (model pollutant) compared to other metal-free catalysts, such as carbon-based ones, and the lower selectivity to CO encourage the potential application of h-BN catalysts in CWPO processes. Through a combined density functional theory calculations, experimental reactions and catalyst characterization approach, a com- prehensive study on the reaction mechanism has been conducted. According to this, only defected B atoms in the h-BN layer, protonated as B-(OH2)+, decompose the hydrogen peroxide into highly reactive hydroxyl radicals. The radical species diffuse towards inner h-BN regions and react with the phenol adsorbed by π-π interaction on the h-BN surface. Oxidation by-products cause carbonaceous deposits and progressive deactivation of the h-BN catalyst that can be directly regenerated by burning off in air.Comunidad de Madrid-S2018/EMT-4341Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación de España, y fondos FEDER de la Unión Europea (MCIU/AEI/FEDER, UE)-RTI2018-095052-B-I00Ministerio de Ciencia e Innovación de España y EU-FEDER-PID2019-106871 GB-I00Junta de Andalucía-FEDER-US-1381410Comunidad de Madrid-PEJD-2018-PRE/AMB-901

    Understanding the active sites of boron nitride for CWPO: An experimental and computational approach

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    [EN] Hexagonal boron nitride (h-BN) has been explored as a catalyst for degrading persistent organic pollutants in wastewater by Catalytic Wet Peroxide Oxidation (CWPO). Herein, the superior activity of the h-BN on the phenol degradation (model pollutant) compared to other metal-free catalysts, such as carbon-based ones, and the lower selectivity to CO encourage the potential application of h-BN catalysts in CWPO processes. Through a combined density functional theory calculations, experimental reactions and catalyst characterization approach, a comprehensive study on the reaction mechanism has been conducted. According to this, only defected B atoms in the h-BN layer, protonated as B-(OH), decompose the hydrogen peroxide into highly reactive hydroxyl radicals. The radical species diffuse towards inner h-BN regions and react with the phenol adsorbed by π-π interaction on the h-BN surface. Oxidation by-products cause carbonaceous deposits and progressive deactivation of the h-BN catalyst that can be directly regenerated by burning off in air.The authors thank the financial support by the Community of Madrid and the Government of Spain through the projects: S2018/EMT- 4341 and RTI2018-095052-B-I00 (MCIU/AEI/FEDER, UE), respectively. The work done at the University of Sevilla was funded by Spanish Ministerio de Ciencia e Innovación and EU-FEDER, grant PID2019-106871 GB-I00, and the Junta de Andalucía-FEDER, grant: US-1381410. Also, G. Vega acknowledges the Community of Madrid for the Predoctoral contract PEJD-2018-PRE/AMB-9019, co-financed by the European Social Fund through the Youth Employment Operational Program and the Youth Employment Initiative (YEI) 2018. J. Carbajo thanks the financial support by the Government of Spain for a grant under the Juan de la Cierva_Incorporación programme (IJCI-2017- 32682). The authors would like to thank A. Pérez for performing the BET and TGA measurements

    Price and service competition with maintenance service bundling

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    In many equipment manufacturing industries, firms compete with each other not only on products price, but also on maintenance service. More and more traditional products oriented firms are offering their customers products bundled with maintenance service (P&S bundles). In this study, we examine firms’ incentive to offer customers products bundling with long-term maintenance or repair support service in a duopoly competitive environment. When providing P&S bundles, a firm need to determine the service level (in terms of average response time guarantee for the service in this paper) to offer and needs to build a service facility to handle the maintenance service requirements. Based on the analysis of three sub-game models, we characterize the market conditions in which only one firm, both firms or neither firm will offer P&S bundles. Finally, we analyze the affects of several market factors on firms’ strategy choices

    'Mobile Only' Users Powered by Fixed-Mobile Substitution

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    In a context of partial fixed-mobile substitution, we analyze fixed-mobile bundling and mobile-to-fixed off-loading in a duopoly model in which consumers buy one or two products. A joint purchase discount mitigates fixed-mobile substitutability and consequently reduces mobile-only and fixed-only consumers. Practises like introducing a small discount, applied on a bundle of multiple service or mobile-to-fixed offloading by both operators are analysed. We find that such practises do not have negative impacts on the profits of whole market and lead to both consumers' surplus and welfare gains. The investment incentives in fixed network are positive and can be boosted by FM bundling without considering regulatory intervention and before taking into account of fixed costs. The investment incentives in mobile network are more likely a situation of prisoners' dilemma where operators should invest as long as there are mobile-only consumers

    Competition and Vertical/Agglomeration Effects in Media Mergers: Bagging Bundle Benefits

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    Existing frameworks (such as used by the New Zealand Commerce Commission in its recent evaluation of the proposed merger between Sky Television and Vodafone) require, as a first step, the definition of the relevant markets affected by the merger or vertical integration activity. Historic precedents in the telecommunications sector have tended towards finding that vertical agglomeration effects when network operators integrate downstream into the provision of applications and services to end-consumers are harmful to competition. Such Structure-Conduct-Performance methods of evaluating mergers and other aspects of market performance are problematic when the firm(s) concerned supply many different products, both together in various different bundle forms and separately as individual components. Defining the markets for (merger) analysis on the basis of only one of the components in a possible bundle that the (merged) firm may supply risks overlooking the complex interactions that occur on the demand side when consumers make their purchase decisions. This is especially likely to be an issue in the supply of internet applications and content bundled with broadband internet access. Consumers have heterogeneous preferences for different applications and content (hereafter ‘content’), and will purchase (or access) many different content types. Even though ownership of rights to distribute one content may confer a degree of market power in for the owner-provider over those consumers with very strong preferences for this content over all others, it is not axiomatic that the firm will be able to exert this power over consumers whose preferences are more evenly distributed. The more variety there is in the content bundles available, and the more heterogeneous are consumers’ preferences across the various content types, the greater is the number of possible markets in which interaction is likely to occur and the more problematic it becomes to identify the relevant markets for analysis of mergers and antitrust cases. We propose that classic merger and antitrust analysis based on econometric cost-benefit analysis can be augmented by using simulation and numerical analysis of a range of bundle offers expected to be relevant in decision-making. We develop a simple model and use it to demonstrate how this approach could have informed the recent New Zealand Commerce Commission decision about the proposed Sky-Vodafone merger by offering some quantitative estimates of total and consumer welfare and provider profits under the proposed factual (with bundling) and counterfactual (individual component sales) cases. The approach may also inform other analyses, such as the assessment of the effects of two-sided markets and firm pricing decisions

    Effect of the acrylic acid content on the permeability and water uptake of latex films

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    Acrylic acid (AA) is a monomer commonly employed in emulsion polymerization to provide electrostatic colloidal stability and improve specific film performance. The addition of AA not only modifies the kinetics of the polymerization, but also it takes part in the interaction between colloidal particles, which has a strong influence on their packing and consequent latex film properties. In this contribution a theoretical modeling of the latex film formation is presented and compared to experimental results: water vapor permeability and latex film capacitance are studied as a function of AA content. It has been shown that water uptake is mainly affected by film morphology which in turn is defined by intercolloidal interaction and drying rate.Comment: 16 pages, 7 figure

    Evaluation of Location-Specific Predictions by a Detailed Simulation Model of Aedes aegypti Populations

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    Skeeter Buster is a stochastic, spatially explicit simulation model of Aedes aegypti populations, designed to predict the outcome of vector population control methods. In this study, we apply the model to two specific locations, the cities of Iquitos, Peru, and Buenos Aires, Argentina. These two sites differ in the amount of field data that is available for location-specific customization. By comparing output from Skeeter Buster to field observations in these two cases we evaluate population dynamics predictions by Skeeter Buster with varying degrees of customization.Skeeter Buster was customized to the Iquitos location by simulating the layout of houses and the associated distribution of water-holding containers, based on extensive surveys of Ae. aegypti populations and larval habitats that have been conducted in Iquitos for over 10 years. The model is calibrated by adjusting the food input into various types of containers to match their observed pupal productivity in the field. We contrast the output of this customized model to the data collected from the natural population, comparing pupal numbers and spatial distribution of pupae in the population. Our results show that Skeeter Buster replicates specific population dynamics and spatial structure of Ae. aegypti in Iquitos. We then show how Skeeter Buster can be customized for Buenos Aires, where we only had Ae. aegypti abundance data that was averaged across all locations. In the Argentina case Skeeter Buster provides a satisfactory simulation of temporal population dynamics across seasons.This model can provide a faithful description of Ae. aegypti populations, through a process of location-specific customization that is contingent on the amount of data available from field collections. We discuss limitations presented by some specific components of the model such as the description of food dynamics and challenges that these limitations bring to model evaluation
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