75 research outputs found

    The Oxy-CaL process: A novel CO2 capture system by integrating partial oxy-combustion with the Calcium-Looping process

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    This paper proposes a novel CO2 capture technology from the integration of partial oxy-combustion and the Calcium-Looping capture process based on the multicycle carbonation/calcination of limestone derived CaO. The concentration of CO2 in the carbonator reactor is increased by means of partial oxy-combustion, which enhances the multicycle CaO conversion according to thermogravimetric analysis results carried out in our work, thus improving the CO2 capture efficiency. On the other hand, energy consumption for partial oxy-combustion is substantially reduced as compared to total oxy-combustion. All in all, process simulations indicate that the integration of both processes has potential advantages mainly regarding power plant flexibility whereas the overall energy penalty is not increased. Thus, the resulting energy consumption per kilogram of CO2 avoided is kept smaller than 4 MJ/kg CO2, which remains below the typical values reported for total oxy-combustion and amine based CO2 capture systems whereas CO2 capture efficiency is enhanced in comparison with the Calcium-Looping process.Ministerio de Economía y Competitividad CTQ2014-52763-C2-2-R, CTQ2014-52763-C2-1-R, MAT2013-41233-

    Correlating Antimicrobial activity and Structure in Montmorillonite modified with Hexadecyltrimethylammonium and Silver

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    The relationship between antimicrobial properties and structure of montmorillonite (MMT) containing hexadecyltrimethylammonium bromide (HDTMA-Br) and silver (Ag) was determined. HDTMA was adsorbed at the clay interlayer by a cation exchange, through the positive head of the ammonium group. At higher surfactant loadings (100 and 200% cation exchange capacity (CEC); MH1 and MH2 samples, respectively) the prevalence of weak adsorption (Van der Waals forces) was observed; whereas below the clay CEC (50%, MH0.5) strong interactions predominated (cation exchange). These different interactions impacted on antimicrobial activity, increasing bactericidal capacity when the surfactant was more available to diffuse. For organo-montmorillonites (OMMT) and all samples with Ag, zeta potential pointed out electrical charge changes on the outer surface, respect to MMT. XPS analyses showed peaks attributed to clusters formation, silver oxidation, and Ag0 in MMTAg and MH0.5-Ag. The Ag0 peak was also present in MH1-Ag and MH2-Ag, the later showing an extra peak associated with AgBr. HDMTA+ and Ag adsorbed on the MMT acted synergistically against Staphylococcus aureus. This effect was less noticeable for Escherichia coli and the result was attributed to both, E. coli outer envelope which might lower the efficacy of HDMTA+ adsorbed on the MMT, and decreasing silver proportions when the surfactant loading increased. MH1-Ag presented the best bactericidal properties, showing synergistic effects against S. aureus, while maintaining activity against E. coli compared to MMT-Ag. Understanding MMT-HDMTA-Ag efficacy contributes to the design of new antimicrobial materials for potential applications in health careFil: Fernández Solarte, Alejandra María. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentina. Corporacion Universitaria Minuto de Dios.; ColombiaFil: Blanco Massani, Mariana Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Molina, Vanesa Magali. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Benítez Guerrero, Mónica. Universidad de Malaga. Facultad de Ciencias; EspañaFil: Torres Sánchez, Rosa M.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentin

    Geophotopedia, an open repository of photographs with geographic elements, Pictures of coastal geomorphology

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    Recoge datos de las VII Jornadas de Geomorfología litoralLa Geophotopedia es un repositorio con acceso libre de fotografías clasificadas y georreferenciadas. En este repositorio, cada usuario puede subir imágenes con información geográfica, que serán clasificadas por especialistas teniendo en cuenta lo que se muestra en ellas. Toda la colección de fotografías geolocalizadas está alojada en el portal gratuito flickr.com y bajo una licencia Creative Commons). Con respecto a las áreas costeras, actualmente se incluyen 258 fotos de 12 países diferentes: 68% de formaciones arenosas, 14% de marismas, 7% de morfologías rocosas y el resto de infraestructuras.Geophotopedia is a repository of classified and georeferenced photographs with free access. In this repository any user can upload images (with geographical information), where geographers and people from of other related sciences will classify them according to what is shown in the picture. Moreover, each photograph will be geolocated. All this collection is hosted at the free portal flickr.com and under a Creative Commons license. Regarding the coastal area, it currently includes 258 photos from 12 different countries: 48% of coastal sand formations, 14% of marshes and 7% of rocky morphologies and other infrastructures

    FACTORES PARA EL DISEÑO Y VISUALIZACIÓN DEL AWARENESS EN SISTEMAS GROUPWARE

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    ResumenEn el área de Trabajo Colaborativo Asistido por Computadora (CSCW), los Groupware son sistemas de información que apoyan a equipos de trabajo en la realización de una actividad colaborativa. Estos sistemas proporcionan información a través de mecanismos visuales que los usuarios utilizan para comprender lo que sucede en el desarrollo de una actividad colaborativa. La información mostrada a los equipos apoya la generación de consciencia o awareness de grupo, la cual es clave para la toma de decisiones, comunicación, colaboración y coordinación de los integrantes del equipo. Para la generación eficiente del awareness, se requieren de mecanismos de visualización construidos a partir de la selección de técnicas que brinden y faciliten la generación de conocimiento, sin provocar una carga cognitiva adicional que dificulte y afecte negativamente el desarrollo intrínseco de la actividad. Sin embargo, la falta de convenciones en el diseño del awareness y la gran variedad de definiciones y enfoques, en gran medida provoca la conceptualización de mecanismos ineficientes para la coordinación y organización de los miembros de un equipo. Por tal motivo, en este artículo se presenta un análisis e identificación de los factores para el diseño y visualización de awareness en los Groupware. Con base en los factores identificados, se propone un modelo con los elementos a considerar en el diseño y desarrollo del soporte de awareness.Palabra(s) Clave: Awareness, Groupware, Visualización. FACTORS FOR THE DESIGN AND VISUALIZATION OF AWARENESS IN GROUPWARE SYSTEMSAbstractIn the area of Computer Supported Collaborative Work (CSCW), Groupware are information systems that support work teams in carrying out a collaborative activity. These systems provide information through visual mechanisms that users use to understand what is happening in the development of a collaborative activity. These systems provide information through visual mechanisms that users use to understand what is happening in the development of a collaborative activity. The information shown to the teams supports the generation of awareness or group awareness, which is key to the decision making, communication, collaboration and coordination of the team members. For the efficient generation of awareness, it requires visualization mechanisms built from the selection of techniques that provide and facilitate the generation of knowledge, without provoking an additional cognitive load that hinders and negatively affects the intrinsic development of the activity. However, the lack of conventions in the design of awareness and the wide variety of definitions and approaches largely causes the conceptualization of inefficient mechanisms for the coordination and organization of team members. For this reason, this article presents an analysis and identification of the factors for the design and visualization of awareness in Groupware. Based on the identified factors, we propose a model with the elements to be considered in the design and development of awareness support.Keywords: Awareness, Groupware, Visualization

    Low-ionization pairs of knots in planetary nebulae: physical properties and excitation

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    We obtained optical long-slit spectra of four planetary nebulae (PNe) with low-ionization pair of knots, namely He 1-1, IC 2149, KjPn 8 and NGC 7662. These data allow us to derive the physical parameters and excitation of the pairs of knots, and those of higher ionization inner components of the nebulae, separately. Our results are as follows. 1) The electron temperatures of the knots are within the range 9500 to 14500 K, similar to the temperatures of the higher ionization rims/shells. 2) Typical knots' densities are 500 to 2000 cm^{-3}. 3) Empirical densities of the inner rims/shells are higher than those of the pairs of knots, by up to a factor of 10. Theoretical predictions, at variance with the empirical results, suggest that knots should be denser than the inner regions, by at least a factor of 10. 4) Empirical and theoretical density contrasts can be reconciled if we assume that at least 90% of the knots' gas is neutral (likely composed of dust and molecules). 5) By using Raga et al. (2008) shock modeling and diagnostic diagrams appropriated for spatially resolved PNe, we suggest that high-velocity shocked knots traveling in the photoionized outer regions of PNe can explain the emission of the pairs of knots analysed in this paper.Comment: The paper contains 11 pages (6 figures and 5 tables). Accepted for publication in MNRAS; added last paragraph for subsection 7.

    Alternative Eco-Friendly Methods in the Control of Post-Harvest Decay of Tropical and Subtropical Fruits

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    The effectiveness on several fruits by the application of alternative methods against fungi is summarized in the present chapter. Several investigations have reported the efficacy of these technologies for controlling fungal infections. Currently, high post-harvest loses have been reported due to several factors such as inefficient management, lack of training for farmers, and problems with appropriate conditions for storage of fruits and vegetables. Even now, in many countries, post-harvest disease control is led by the application of chemical fungicides. However, in this time, awareness about fungi resistance, environmental, and health issues has led to the research of eco-friendly and effective alternatives for disease management. The pathogen establishment on fruits can be affected by the application of GRAS compounds like chitosan, essential oils, salts, among others; besides, their efficacy can be enhanced by their combination with other technologies like ultrasound. Thus, the applications of these alternatives are suitable approaches for post-harvest management of fruits

    The miniJPAS survey : white dwarf science with 56 optical filters

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    Aims. We analyze the white dwarf population in miniJPAS, the first square degree observed with 56 medium-band, 145 Å in width optical filters by the Javalambre Physics of the accelerating Universe Astrophysical Survey (J-PAS), to provide a data-based forecast for the white dwarf science with low-resolution (R ∼ 50) photo-spectra. Methods. We define the sample of the bluest point-like sources in miniJPAS with r <  21.5 mag, a point-like probability larger than 0.5, (u − r)< 0.80 mag, and (g − i)< 0.25 mag. This sample comprises 33 sources with spectroscopic information: 11 white dwarfs and 22 quasi-stellar objects (QSOs). We estimate the effective temperature (Teff), the surface gravity, and the composition of the white dwarf population by a Bayesian fitting to the observed photo-spectra. Results. The miniJPAS data are sensitive to the Balmer series and the presence of polluting metals. Our results, combined with those from the Javalambre Photometric Local Universe Survey (J-PLUS) which has a lower spectral resolution but has already observed thousands of white dwarfs, suggest that J-PAS photometry would permit – down to r ∼ 21.5 mag and at least for sources with 7000   7000 K can be segregated from the bluest extragalactic QSOs, providing a clean sample based on optical photometry alone. Conclusions. The J-PAS low-resolution photo-spectra would produce precise effective temperatures and atmospheric compositions for white dwarfs, complementing the data from Gaia. J-PAS will also detect and characterize new white dwarfs beyond the Gaia magnitude limit, providing faint candidates for spectroscopic follow-up
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