386 research outputs found
CO2 hydrogenation to methanol on In2O3/ZrO2 fibrillar catalysts.
Hydrogenation of CO2 to produce methanol is regarded as one of the most promising processes for achieving full deployment of carbon capture, utilization and storage technologies, which are needed to decrease the emission of greenhouse gases. In this communication, In2O3-ZrO2 nanostructured fibrillar catalysts, prepared by electrospinning technique, has been proposed for CO2 hydrogenation. The effect of the calcination temperature as well as the indium loading on the CO2 conversion have been evaluated.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Carbon-based biomass-derived catalysts for deoxygenation of fast pyrolysis bio-oil
Producing energy and chemicals from biomass is an interesting alternative for replacing conventional fossil sources with a renewable feedstock while enabling zero net greenhouse gases emissions. Particularly, fast pyrolysis of biomass waste enables the production of bio-oil, which can be upgraded to biofuels or value-added chemicals. The sustainability of this process can be enhanced by preparing carbon-based catalysts from the same biomass waste used as raw material for the biooil production, decreasing the inputs of the process and allowing recovery and recycle of the active phase by combustion of the carbon substrate. In this work, catalytic fast pyrolysis of olive stone residues was studied using mesoporous carbon-based acid catalysts prepared by activation with H3PO4 of olive stones.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Las posibilidades de EAD (Encoded Archival Description) 2002 para la descripción archivística multinivel: Un caso concreto de aplicación
Se presenta EAD (Encoded Archival Description) versión 2002 como estándar de facto para el tratamiento y difusión de instrumentos tradicionales de descripción archivística. Se analiza, comenta y critica el sistema previsto en EAD para tratar instrumentos de descripción a dos o más niveles. Así, se expone el mecanismo general habilitado y se relaciona con la definición y las cuatro reglas de descripción multinivel enunciadas en la Norma internacional general de descripción archivística ISAD(G); se analizan los niveles que contempla de forma estándar, también comparados con los previstos en ISAD(G), y las diversas posibilidades y alternativas disponibles en EAD en relación con la descripción multinivel; finalmente se critican aquellos aspectos susceptibles de simplificación o mejora. Se cita un caso real de aplicación de EAD 2002 a un instrumento de descripción archivística multinivel: la versión electrónica del Catálogo de Pergaminos del Archivo Municipal de Córdoba
Aportaciones del Foro de expertos sobre la cohesión, la diversidad y el desarrollo territorial: reflexiones en torno al libro verde de la Comisión de las Comunidades Europeas
Removal of paracetamol on biomass-derived activated carbon: Modeling the fixed bed breakthrough curves using batch adsorption experiments
The remediation of paracetamol (PA), an emerging contaminant frequently found in wastewater treatment plants, has been studied in the low concentration range (0.3–10 mg L−1) using as adsorbent a biomass-derived activated carbon. PA uptake of up to 100 mg g−1 over the activated carbon has been obtained, with the adsorption isotherms being fairly explained by the Langmuir model. The application of Reichemberg and the Vermeulen equations to the batch kinetics experiments allowed estimating homogeneous and heterogeneous diffusion coefficients, reflecting the dependence of diffusion with the surface coverage of PA. A series of rapid small-scale column tests were carried out to determine the breakthrough curves under different operational conditions (temperature, PA concentration, flow rate, bed length). The suitability of the proposed adsorbent for the remediation of PA in fixed-bed adsorption was proven by the high PA adsorption capacity along with the fast adsorption and the reduced height of the mass transfer zone of the columns. We have demonstrated that, thanks to the use of the heterogeneous diffusion coefficient, the proposed mathematical approach for the numerical solution to the mass balance of the column provides a reliable description of the breakthrough profiles and the design parameters, being much more accurate than models based in the classical linear driving force.We gratefully thank Junta de Andalucía (P09-FQM-5156) and Spanish Ministry of Economy and Competitiveness (MINECO – Spain) (Project CTQ2012-36408) and Fondo Europeo de Desarrollo Regional (FEDER – Spain) for financial support
MgO-containing porous carbon spheres derived from magnesium lignosulfonate as sustainable basic catalysts
The presence of alkalis in lignosulfonate allows an easy preparation of sustainable MgO-containing carbon catalysts with surface basicity by carbonization of magnesium lignosulfonate and/or further partial gasification of the produced char with CO2. Carbon spheres with different chemical and physical properties were obtained from lignosulfonate treated at temperatures ranging from 500 to 900 ºC. Carbonization at 900 °C generates hollow porous carbon spheres (pore volume of 0.20 cm3/g and apparent surface area of 465 m2/g) with magnesium content of 12%. A kinetic study of CO2 gasification of the carbon spheres obtained at 900 °C at temperatures in the range of 700 – 800 °C revealed that the gasification rate can be accurately described by the random pore model up to conversion values of 0.5. Based on this study, in order to develop additional porosity on the carbon spheres obtained at 900 °C, a partial gasification with CO2 at 750 °C for 30 min was carried out, reaching surface areas higher than 700 m2/g and 15.3% of Mg loading, with an overall preparation yield of 30%. All the obtained carbon materials were tested as catalyst for 2-propanol decomposition, showing a high selectivity to acetone, evidencing the basic character of these carbon catalysts. The highest activity and selectivity were shown by the CO2-activated carbon spheres (conversion and acetone selectivity higher than 90% at 420 °C), indicating that magnesium lignosulfonate is an attractive raw material for the preparation of sustainable carbon catalysts for biorefinery applicationsThe authors wish to thank MICINN (RTI2018-097555-B-100) and Junta de Andalucía (UMA18-FEDERJA-110 and P18-RT-4592) for financial support. M.G.R. acknowledges the assistance of MICINN through an FPU Grant (FPU 18/01402). // Funding for open access charge: Universidad de Málaga / CBU
Aplicación del formato hipertextual a textos legales: el ejemplo del código del Mercosur
Texto de la comunicación incluida en el Congreso Internacional de Información - INFO 99, del 2 al 6 de octubre de 1999, en La Habana (Cuba), organizado por el IDICT (Instituto de Información Científica y Tecnológica). La comunicación fue presentada, pero no se incluyó en las actas por un error en la edición de las mismas.Descripción del proyecto que realizaron la editorial Ciudad Argentina (Buenos Aires, Argentina) y el Departamento de Biblioteconomía y Documentación de la Universidad Carlos III de Madrid (España) para la conversión del Código del Mercosur a un formato electrónico e hipertextual. El proyecto permitió llevar a la práctica las similitudes conceptuales entre la interrelación de textos legales y el enlace de los mismos mediante hipertextos. La aplicación se desglosó en una serie de tareas consecutivas (análisis documental del texto, organización electrónica del mismo, establecimiento de hiperenlaces entre textos seleccionados), partiendo de una concepción que pretendía unos resultados legibles (en cualquier plataforma, con aplicaciones gratuitas, mediante un lenguaje extendido y fácil de usar), así como los resultados finales. En su realización, se constató la necesidad de emplear equipos interdisciplinares (expertos documentales en derecho y técnicos en documentación automatizada), atender a la utilidad final del producto, emplear tecnologías más sencillas pero más potentes, y facilitar la accesibilidad al mayor número posible de usuarios
Autovaloración de estudiantes universitarios de su participación en programas de aprendizaje-servicio orientados a la inclusión educativa de menores en riesgo de exclusión social
Positive affect is inversely associated with mortality in individuals without depression
Background: Some studies have analyzed the relation between well-being and mortality but none of them have attempted to disentangle the differential influence that positive affect, negative affect, and evaluative well-being might have on mortality using a longitudinal design in the general population and measuring independently and accurately each component of well-being. The aim of the present study is to assess the association of these well-being components with mortality after adjusting for health and other lifestyle factors and to analyze whether this association is different in people with and without depression. Methods: A nationally representative sample of 4753 people from Spain was followed up after 3 years. Analyses were performed with Cox regression models among the total sample and separately in people with and without depression. Results: In the analyses adjusted for age, sex, and years of education, all three well-being variables showed separately a statistically significant association with mortality. However, after adjustment for health status and other confounders including the other well-being components, only positive affect remained as marginally associated with a decreased risk of mortality in the overall sample [HR = 0.87; 95% CI = 0.73-1.03], in particular among individuals without depression [HR = 0.82; 95% CI = 0.68-0.99]. Conclusion: Positive affect is inversely associated with mortality in individuals without depression. Future research should focus on assessing interventions associated with a higher level of positive affect.The research leading to these results has received funding from the European Union Horizon 2020 Framework Programme for Research and Innovation under grant agreement 635316 (ATHLOS Project), from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement number 223071 (COURAGE in Europe), from the Spanish Ministry of Science and Innovation ACI- Promociona (ACI2009-1010), from the Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM) Mental Health and Disability Instruments Library Platform, and from the Instituto de Salud Carlos III-FIS research grants PS09/00295, PS09/01845, PI12/01490, and PI13/00059. Projects PI12/01490 and PI13/00059 have been co-funded by the European Union European Regional Development Fund (ERDF) “A Way to Build Europe.” The study was supported by the Instituto de Salud Carlos III Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). NMM is supported by the programme “Contratos predoctorales para Formación de Personal Investigador, FPI-UAM,” Universidad Autónoma de Madrid, Spai
Plant catalases as NO and H2S targets
Catalase is a powerful antioxidant metalloenzyme located in peroxisomes which also plays a central role in signaling processes under physiological and adverse situations. Whereas animals contain a single catalase gene, in plants this enzyme is encoded by a multigene family providing multiple isoenzymes whose number varies depending on the species, and their expression is regulated according to their tissue/organ distribution and the environmental conditions. This enzyme can be modulated by reactive oxygen and nitrogen species (ROS/RNS) as well as by hydrogen sulfide (H2S). Catalase is the major protein undergoing Tyr-nitration [post-translational modification (PTM) promoted by RNS] during fruit ripening, but the enzyme from diverse sources is also susceptible to undergo other activity-modifying PTMs. Data on S-nitrosation and persulfidation of catalase from different plant origins are given and compared here with results from obese children where S-nitrosation of catalase occurs. The cysteine residues prone to be S-nitrosated in catalase from plants and from bovine liver have been identified. These evidences assign to peroxisomes a crucial statement in the signaling crossroads among relevant molecules (NO and H2S), since catalase is allocated in these organelles. This review depicts a scenario where the regulation of catalase through PTMs, especially S-nitrosation and persulfidation, is highlighted
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