Diagrama de flujo para prevención secundaria de la obesidad según el origen del problema: P.E.I.C. “Bimbela”

Objective: Development of a flowchart that allows the professional Primary Care to carry out the decision with the obese patient, depending on the source of the problem.Methods: Based on the premises of Virginia Henderson, on factors influencing the independence of patients to meet their basic needs: lack of strength (can not), lack of will (do not want) or lack of knowledge (do not know); it has developed a decision diagram depends on "the source of the problem": “Comprehensive Comunity Educational Project (C.C.E.P.) Bimbela”.Results: Cases with criteria consistent inclusion non-pharmacologic dietoterapic program for obese adults in consultation Community Nursing. The program took place between January 2012 and December 2013 (96 weeks).Conclusion: The flowchart can provide carry out the decision in Primary Care, allowing improve adherence to weight loss and maintenance program.Objetivo: Elaboración de un diagrama de flujo que permita al profesional de Atención Primaria llevar a cabo la toma de decisiones con el paciente obeso, en función del origen del problema. Material y Métodos: Partiendo de las premisas de Virginia Henderson sobre los factores que influyen en la independencia de los pacientes para cubrir sus necesidades básicas: falta de fuerza (no puede), falta de voluntad (no quiere) o falta de conocimientos (no sabe); se ha elaborado un diagrama de decisión según “el origen del problema”: “Proyecto Educativo Integral Comunitario (P.E.I.C.) Bimbela”.Resultados: Se captaron aquellos casos con criterios de inclusión compatibles con un programa dietoterápico no farmacológico para pacientes obesos adultos en la consulta de Enfermería Comunitaria. Se desarrolló entre Enero 2012 y Diciembre 2013 (96 semanas).Conclusión: El diagrama de flujo permite facilitar la toma de decisiones en  Atención Primaria, logrando una buena adherencia al programa de adelgazamiento y mantenimiento de peso

30 años conviviendo con el SIDA

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Application of a modeling tool to describe fly ash generation, composition, and melting behavior in a wheat straw fired commercial power plant

Ash behavior is a key operational aspect of industrial-scale power generation by means of biomass combustion. In this work, FactSage™ 6.4 software was used to develop and assess three models of wheat straw combustion in a vibrating grate-fired commercial boiler of 16 MWth, aiming to describe the inorganic elements release as well as fly ash melting behavior and composition. Simulations were carried out solving four consecutive calculation stages corresponding to the main plant sections. Chemical fractionation was adopted in order to distinguish between reactive, inert and partially reactive biomass fractions. The developed models allow take into account different levels of partial reactivity, values of the temperature for each sub-stage on the grate, and ways to apply entrained streams based on data from the elemental analyses of the fly ashes. To this end, two one-week experimental campaigns were conducted in the plant to carry out the sampling. It has been found that considering chemical fractionation is indispensable to describe the entrainment of solid particles in the gas stream. In addition, the best results are obtained by adopting a small reactivity (2%) of the inert fraction. As for fly ash composition, the concentrations of the major elements showed good agreement with the results from the chemical analyses. In the case of S and Cl, calculations revealed a match with gas cooling effects in the superheaters as well as an entrainment effect. The melting behavior together with the presence of KCl and K2SO4 condensates, point out at possible corrosion phenomena in walls at temperatures of 700–750 °C.This research was funded by the Spanish Ministerio de Economía y Competitividad (MINECO), in accordance with the provisions of article 31 Regulation of Law 38/2003, of November 17, General Subsidies, approved by Royal Decree 887/2006, of July 21. Funding was received within the framework of the MULTIBOM (Development of Multi-fuel Biomass Combustion Technology for High-Power Electrical Production) project, which has received public funding from the INNPACTO subprogramme (Prj. Re. num. IPT-2012-0155-120000). Luis M. Gandía thanks Banco de Santander and Universidad Pública de Navarra for their financial support under 'Programa de Intensificación de la Investigación 2018' initiative, as well as Spanish Ministerio de Ciencia, Innovación y Universidades and the European Regional Development Fund (ERDF/FEDER) (grant RTI2018-096294-B-C31)

Catalytic hydroprocessing of lignin β-O-4 ether bond model compound phenethyl phenyl ether over ruthenium catalysts

The catalytic hydroprocessing of phenethyl phenyl ether (PPE), a model compound of one of the most significant ether linkages within lignin structure, β-O-4, has been studied. Reactions were carried out using two ruthenium-based catalysts, supported on different materials: 3.8 wt.% Ru/C and 3.9 wt.% Ru/Al2O3. Aiming at studying the reaction mechanism, experiments were carried out at 150 °C and 25 bar in H2 atmosphere, with varying feed to catalyst mass ratios and reaction time. Differences between the relative importance of the steps of the mechanism were observed when using those two catalysts. The most significant finding was the predominance of the cleavage of Cβ-O bonds compared to the cleavage of the Caryl-O when using Ru/Al2O3 as catalyst; whereas with Ru/C, the two routes were nearly equivalent. It has been observed that the kinetic model describes the general tendencies of consumption and formation of the different products, but some over/under estimation of concentrations occurs. Finally, the effect of temperature was also explored by carrying out reactions at 100 and 125 °C, observing that decreasing temperature from 150 to 125 or 100 °C favored the dimer hydrogenation route versus the hydrogenolysis of the ether bonds

SYNTHESIS GAS BY CATALYTIC STEAM REFORMING OF BIO-OIL

The concept of biomass refinery or biorefinery, has attracted great attention during the last decade. The idea is to process lignocelullosic residues converting the resulting products or fractions of them into a variety of fine chemicals or high added value products and raw materials serving as a feedstock for other valuable chemicals and commodities. One of the most interesting paths for the thermochemical conversion of biomass is fast pyrolysis of biomass followed by catalytic steam reforming of the liquid pyrolysis products (bio-oil) or its fractions. The product gas from this process is a H2 rich with moderate CO content which, conveniently conditioned, may serve as a valuable feedstock in the production of various chemicals, offering numerous possibilities. The bio-oil is a complex mixture of oxygenated organic compounds and water in a 85/15 mass ratio. The main constituents include alcohols, carboxylic acids, sugars, aldehydes and ketones, as well as more complex carbohydrates and lignin derived materials. It can be split into two main fractions by water addition: a highly valued organic fraction that can be used as a feedstock to produce fine chemicals, and water insoluble and an aqueous fraction, less valuable, that can be catalytically steam reformed. The catalysts for the steam reforming process are usually nickel based, similar to those commercial employed in the catalytic steam reforming of natural gas and naphthas. Their main advantages are their high activity and selectivity to hydrogen, as well as their relative low cost compared to other catalysts based on noble metals. However, there still remains the challenge of developing nickel based catalysts with an adequate resistance to deactivation by coke deposition. Therefore, the aim of the present work is to develop a suitable nickel coprecipitated catalyst for the catalytic steam reforming of the aqueous fraction of biomass pyrolysis liquids. The catalyst must be not only active and selective to hydrogen, but resistant to deactivation by coke deposition and to attrition, in order to be fed in a future in a fluidized bed setup. In the present work, the catalytic steam reforming of model compounds of the aqueous fraction of bio-oil has been studied with Ni/Al coprecipitated catalysts in a microscale fixed bed setup. Several catalysts with different nickel contents have been tested at 650 ºC. The effect of promoters (Cu and Mg) on product gas yields has also constituted a matter of study. Further work will be accomplished with the aqueous fraction of bio-oil. The experimental setup consists of a fixed bed inside a tubular quartz reactor operating at atmospheric pressure. The bed is constituted by a mixture of sand (used as inert filler) and a Ni-based catalyst. The experimental procedure implies in-situ reduction of the catalyst with hydrogen and further reforming of the organic. The exiting flow is forced into a condenser and finally the remaining product gases are analysed on-line with a Micro GC before venting. Typically, 20-30 mg of catalyst were used and the organic was fed by means of a HPLC metering pump

Obtención de carbones activos a partir de lignina procedente del pasteado semiquímico de Miscanthus giganteus

En este Proyecto Fin de Carrera se ha estudiado la producción de carbones activos a través de un proceso de pirolisis en tres etapas. Dichas etapas son: una pirolisis a baja temperatura (torrefacción), liberando fundamentalmente CO2 y vapor de agua, seguida de una pirolisis del material a temperaturas típicas de 500-600 ºC para generar el char precursor del carbón activo, y una última etapa de activación de los precursores generados para obtener el carbón activo aprovechando los gases liberados en la primera etapa. El presente proyecto se ha centrado en el estudio de la tercera etapa, la activación del char precursor obtenido en la segunda etapa de pirolisis. El objetivo principal del presente proyecto es la preparación y caracterización de carbones activos a partir del char precursor mediante una activación física con CO2 puro. Para llevar a cabo los experimentos, se utilizaron fundamentalmente tres plantas experimentales; la planta de pirólisis, la de activación y la de desulfuración. La planta de pirólisis se diseñó y construyó para que permitiera la preparación de suficiente cantidad de char precursor para efectuar los posteriores experimentos de activación. La pirólisis se llevó a cabo a diferentes temperaturas (500, 550 y 600 ºC) con un tiempo de retención a la temperatura final (“hold time”, HT) de 0 minutos y calentamiento en rampa de 10 ºC/min pasando continuamente N2 para conseguir una atmósfera inerte. La activación física del material se realizó durante 20 minutos a diferentes temperaturas (700, 850 y 900 ºC) con un calentamiento hasta la etapa de activación de 10 ºC/min. Asimismo, se efectuó la caracterización de las materias primas mediante análisis elemental e inmediato, y la determinación del poder calorífico de las mismas. También se han caracterizado los sólidos obtenidos tras las etapas de pirólisis y de activación mediante adsorción de N2 (por los métodos BET y BJH), difracción de rayos X (XRD) y la determinación del poder calorífico de los chares precursores obtenidos en la etapa de pirólisis. Finalmente se realizó un experimento de adsorción de H2S de una corriente gaseosa con un carbón activo obtenido tras una etapa de pirólisis a 600 ºC y posterior activación a 850 ºC. El experimento de desulfuración se efectuó durante dos horas a 900 ºC utilizando un caudal de gas de 50 mL N/min con un contenido de H2S del 0,5 % (v/v), analizando la corriente de gas a la salida del reactor mediante cromatografía de gases

Oxygen/steam charcoal gasification in a fluidized alumina bed

Mixtures of oxygen and steam were used as gasifying agents to produce a gas stream with high hydrogen content. The effects of the equivalence ratio (ER) and steam to carbon ratio (S/C) on gasification performance were studied at 900 ºC. The highest hydrogen yield (0.412 Nm3/kg charcoal) and apparent energy efficiency (33.43%) were achieved using a mixture that had a S/C ratio of 0.625 and an ER equal to 0.3 (pure oxygen). The results showed that the carbon conversion improved when the ER and the S/C ratio were augmented, and that the production of tars increased when the S/C ratio was increased. The use of γ-Al2O3 as bed material was effective in the cracking of the tars, as well as on the cracking of hydrocarbons heavier than methane. Please click Additional Files below to see the full abstract