971 research outputs found
Removal of hydrogen sulphide by immobilized Thiobacillus thioparus in a biofilter packed with polyurethane foam
Optimal electricity price calculation model for retailers in a deregulated market
The electricity retailing, a new business in deregulated electric power systems, needs the development of efficient tools to optimize its operation. This paper defines a technical-economic model of an electric energy service provider in the environment of the deregulated electricity market in Spain. This model results in an optimization problem, for calculating the optimal electric power and energy selling prices that maximize the economic profits obtained by the provider. This problem is applied to different cases, where the impact on the profits of several factors, such as the price strategy, the discount on tariffs and the elasticity of customer demand functions, is studied. © 2005 Published by Elsevier Ltd
Choroidal Vessel Wall: Hypercholesterolaemia-Induced Dysfunction and Potential Role of Statins
Forest landscape restoration in the drylands of Latin America
Forest Landscape Restoration (FLR) involves the ecological restoration of degraded forest landscapes, with the aim of benefiting both biodiversity and human well-being. We first identify four fundamental principles of FLR, based on previous definitions. We then critically evaluate the application of these principles in practice, based on the experience gained during an international, collaborative research project conducted in six dry forest landscapes of Latin America. Research highlighted the potential for FLR; tree species of high socioeconomic value were identified in all study areas, and strong dependence of local communities on forest resources was widely encountered, particularly for fuelwood. We demonstrated that FLR can be achieved through both passive and active restoration approaches, and can be cost-effective if the increased provision of ecosystem services is taken into account. These results therefore highlight the potential for FLR, and the positive contribution that it could make to sustainable development. However, we also encountered a number of challenges to FLR implementation, including the difficulty of achieving strong engagement in FLR activities among local stakeholders, lack of capacity for community-led initiatives, and the lack of an appropriate institutional and regulatory environment to support restoration activities. Successful implementation of FLR will require new collaborative alliances among stakeholders, empowerment and capacity building of local communities to enable them to fully engage with restoration activities, and an enabling public policy context to enable local people to be active participants in the decision making process. © 2012 by the author(s). Published here under license by the Resilience Alliance
Hydrogen Generation by Treatment of Aluminium Metal with Aqueous Solutions: Procedures and Uses
Storing, reporting and comparing proteomics experiments using the miape generator tool
Comunicaciones a congreso
Eficacia biodescontaminante obtenida mediante la aplicación de Virkon®, Perasafe® e hidróxido sódico sobre superficies de alto riesgo microbiológico
La eficacia de la actividad biodescontaminante de los productos Virkon®, Perasafe® e hidróxido sódico, ha sido evaluada. Los compuestos fueron ensayados en boxes de laboratorios de contención con bioseguridad nivel 3 (NCB3), destinados a alojar animales de experimentación para el estudio de peste porcina africana (PPA), fiebre aftosa (FA) y virus del Nilo Occidental (VNO). Las muestras procedentes de diferentes puntos fueron obtenidas mediante placas RODAC, antes y después de la aplicación del tratamiento desinfectante sobre la superficie ensayada, y los resultados obtenidos fueron expresados como unidades formadoras de colonias por mililitro (ufc/ml). Los resultados obtenidos indican que todos los compuestos ensayados demostraron un alto nivel de eficacia biodescontaminante, pero sin embargo el efecto inducido el compuesto Perasafe® aportó un nivel de eficacia superior al obtenido con los otros compuestos. Así, estos resultados permiten afirmar la idoneidad de Perasafe® para la desinfección de espacios con nivel 3 de bioseguridad.Biodecontaminant effectiveness obtained in surfaces treated with Virkon®, Perasafe®, and sodium hydroxide has been evaluated. The selected compounds were used in boxes from Biosafety Level 3 containment laboratories (NCB3) for animals exposed to classical swine fever (CSF), foot and mooth disease (FMD), and west nile virus (WNV). The samples from selected points were obtained by mean RODAC plates, before and after to the use of selected compounds on surfaces, and the results obtained were expressed as colony-forming units per milliliter (cfu/ml). Results shown that all compounds assayed demonstrated high biodecontaminant efficacy levels; but however Perasafe® was more effective than others compounds assayed. Thus, these results allow affirming that Perasafe® is suitable for the disinfection of surfaces from NCB3 spaces
Influence of nozzle geometry on ignition and combustion for high-speed direct injection diesel engines under cold start conditions
Starting at low temperatures (below 0 °C) is an important issue for current and near future diesel engine technology. Low ambient temperature causes long cranking periods or complete misfiring in small diesel engines and, as a consequence, an increased amount of pollutant emissions. This paper is devoted to study the influence of nozzle geometry on ignition and combustion progression under glow-plug aided cold start conditions. This study has been carried out in an optically accessible engine adapted to reproduce in-cylinder conditions corresponding to those of a real engine during start at low ambient temperature. The cold start problem can be divided in two parts in which nozzle geometry has influence: ignition and main combustion progress. Ignition probability decreases if fuel injection velocity is increased or if the amount of injected mass per orifice is reduced, which is induced by nozzles with smaller hole diameter or higher orifice number, respectively. Combustion rates increase when using nozzles which induce a higher momentum, improving mixture conditions. For these reasons, the solution under these conditions necessarily involves a trade-off between ignition and combustion progress.Authors thank the Spanish Ministry of Innovation and Science for the financial support through the project OPTICOMB (reference code: TRA2007-67961-C03-C01). Authors also thank Daniel Lerida Sanchez de las Heras for his outstanding work in the facility set-up and adaptation and for his support during the tests.Desantes Fernández, JM.; García Oliver, JM.; Pastor Enguídanos, JM.; Ramírez Hernández, JG. (2011). Influence of nozzle geometry on ignition and combustion for high-speed direct injection diesel engines under cold start conditions. Fuel. 90(11):3359-3368. https://doi.org/10.1016/j.fuel.2011.06.006S33593368901
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