31 research outputs found
Nuestra memoria de la guerra para vivir en paz
Esta memoria da cuenta de sus vidas, planes,
inconformidades, desencuentros, pero también insiste en sus sueños de vivir con dignidad y con justicia social.
Desde el año 2005, investigadoras de la universidad iniciaron un primer acercamiento a través de una
investigación de una enfermedad cultural, propia de la población indígena de la costa Caribe nicaragüense
–grisi siknis–. En los hallazgos identificamos que el tema del conflicto bélico era un aspecto muy presente en
la memoria de la población, es decir, la población mantiene una carga pesada de la historia con consecuencias
psicológicas profundas. Un segundo acercamiento al tema fue en el año 2007, prácticamente una parte del mismo
equipo de investigadoras nos adentramos al Wangki, esta vez para profundizar en la forma en que el desarraigo
vivido por la población del río Coco, marcó la vida de las mujeres miskitu debido al hecho de ser sacadas a la
fuerza de sus comunidades, la división de sus familias, los dolores y sufrimientos por la zozobra de tener a sus
maridos e hijos en los frentes de guerra, en las cárceles, pero además tener que asumir solas la responsabilidad
del sostén de la familia. Muy duro para ellas fue el hecho de perder lo que junto a su familia habían edificado
durante toda su vida. La expulsión del río Coco, significó el rompimiento del espacio geográfico y sociocultural
determinado por parámetros culturales que constituyen un pasado común, así como por las redes económicas
y sociales. Finalmente, la situación vivida por la población del río Coco evidencia que el contexto de guerra
dejó consecuencias invisibles en las personas: dolores, llagas y martirios en el alma y en el pensamiento, que no
cicatrizan tan fácilmente como las heridas físicas. La selección de las tres comunidades en estudio responde a diferentes criterios: San Carlos fue seleccionado
debido a que antes del traslado forzado por el gobierno de ese entonces, hubo una serie de brotes de actividades
hostiles en contra del gobierno por parte del recién organizado movimiento indígena armado. San Carlos y Asang
tienen tendencias ideológico/ políticas contrarias que afloran con más fuerza en los períodos de campañas políticas
de procesos electorales, pero sobre todo por la historia de desarraigo que vivieron ambas comunidades. Para el
caso de la comunidad de Santo Tomás de Umra, fue incluida para tener y abordar la visión vivida por la población
indígena Sumu/Mayangna
Degradation pathways of emerging contaminants using TiO2-activated carbon heterostructures in aqueous solution under simulated solar light
This work deals with the degradation of three emerging contaminants (acetaminophen, ibuprofen and antipyrine) in water under simulated solar light using different catalysts of TiO2/activated carbon heterostructures. The heterostructures, based on anatase phase, were successfully synthesized following three different methods (solvothermal, microwave-assisted and sol-gel), using lignin as carbon precursor. The sol-gel photocatalyst only yielded 50% conversion of acetaminophen and a low mineralization (15%), probably due to the higher crystal and particle size and lower surface area of this heterostructure, as a consequence of the higher temperature reached during the heat-treatment included in this synthesis route to achieve anatase crystallization. In contrast, the heterostructure prepared by the microwave-assisted procedure achieved complete conversion after 6 h of reaction. Regarding the contaminants, ibuprofen was the most easily removed, requiring 3 h for complete disappearance, while antipyrine showed the highest resistance to photodegradation, not being completely removed after 6 h. The photocatalytic performance was also evaluated for a mixture of these three pharmaceuticals at different initial pH. The fastest and highest mineralization (ca. 50%) occurred around neutral pH. The study proposes the oxidation degradation pathways of the three pharmaceuticals under solar-simulated irradiation from the analysis of the reaction intermediatesThe authors acknowledge the financial support from Spanish MINECO (project CTQ2016-78576-R). M. Peñas-Garzón thanks Spanish MECD for FPU16/00576 grant. Authors thank the Research Support Services of the University of Extremadura (SAIUEx) for its technical and scientific suppor
Comparison of different precious metals in activated carbon-supported catalysts for the gas-phase hydrodechlorination of chloromethanes
Four precious metals supported on activated carbon are compared as catalysts in the gas-phase hydrodechlorination (HDC) of chloromethanes. The intrinsic activity or turnover frequency (TOF) of the catalysts follows the order Pd/C > Rh/C > Pt/C > Ru/C in the HDC of dichloromethane (DCM) while the sequence Pd/C > Pt/C > Rh/C > Ru/C was found for the HDC of chloroform (TCM). High selectivities to non-chlorinated products were obtained in all cases except for the HDC of TCM with Rh/C and Ru/C where the selectivity to DCM greatly depends on the operating conditions. A wider diversity of non-chlorinated hydrocarbons was obtained as reaction products with these two catalysts, especially in the HDC of TCM, favoring the formation of carbonaceous deposits which provoked a marked deactivation of the catalysts. In contrast, CH4 was the only non-chlorinated product obtained with the Pt/C catalysts which showed by far the highest stability. Different reaction pathways were found depending on the catalyst and the starting chloromethane. The different reactivity of the metals is explained in terms of their different electronic structure and the physicochemical properties of the catalystsThe authors gratefully acknowledge financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) through the project CTM2011-28352. M. Martín Martínez acknowledges the Spanish Ministerio de Ciencia e Innovación (MICINN) and the European Social Fund for her research grant. J. Bedia also wishes to thank the MICINN for financing his research through the “Juan de la Cierva” postdoctoral program
Mixed Ti-Zr metal-organic-frameworks for the photodegradation of acetaminophen under solar irradiation
Mixed Ti-Zr metal-organic-frameworks (MOFs)have been synthesized and tested as photocatalysts under solar-simulated radiation using acetaminophen (ACE)as target pollutant. These materials were obtained upon partial substitution of Ti by Zr atoms in the crystalline structure of NH2-MIL-125(Ti)MOF. The effect of the Ti:Zr molar ratio on their characteristics and catalytic behaviour has been analysed. Materials with high Zr relative amount (60–80%)showed amorphous structure and low solar-photocatalytic activity. In contrast, lower Zr proportions resulted in new MOFs with well-defined crystalline structure and high activity for the solar photocatalytic degradation of ACE, even higher than that of the bare Ti MOF. Results with scavengers allowed concluding that O2[rad]− radicals are the main reactive species, although photogenerated [rad]OH radicals and electrons also contribute to the degradation. The stability of the most active photocatalyst was confirmed upon three successive runsThe authors acknowledge the financial support from Spanish MINECO (project CTQ2016-78576-R). M. Peñas-Garzón thanks Spanish MECD for FPU16/00576 grant. Authors thank the Research Support Services of the University of Extremadura (SAIUEx) for its technical and scientific support. We also thank to Dr. Juan Cabanillas for his help with PL measurement
Hydrodechlorination of dichloromethane with mono- and bimetallic Pd-Pt on sulfated and tungstated zirconia catalysts
Monometallic (Pt or Pd) and bimetallic (Pt-Pd) catalysts supported on zirconia promoted with sulfate (SZ) or tungsten oxide (WZ) were prepared and tested in the gas-phase hydrodechlorination of dichloromethane. The catalysts showed a high selectivity to non-chlorinated products (between 80% and 90% at 250 °C) being methane the main reaction product. As a general trend, the WZ catalysts yielded significantly higher dichloromethane conversion than the SZ ones, yielding all the catalysts initial conversions higher than 80% at a reaction temperature of 250 °C. However, the former showed a very poor stability regardless of the metallic active phase. On the other hand, the presence of palladium in the sulfated zirconia catalyst avoids deactivation as proved in long-term experiments (80-h time on stream). XPS and elemental analyses of the used catalysts suggest that adsorption of organochlorinated species is a cause of deactivation by blocking the active sites. In the monometallic SZ Pt catalyst, deactivation occurs also by poisoning of the Pt sites by the H 2S resulting from sulfate reduction under the hydrogen-rich gas atmosphere. The metal particle size appears to be a critical point with regard to stability of the catalysts. The one with the highest dispersion showed the highest stability with no signs of deactivation after more than 80 h on streamThe authors are grateful to the Spanish “Ministerio de Ciencia e Innovación (MICINN)” for financial support (projects CTM2008-04751 and CTM2011-28352). J. Bedia acknowledges the Spanish MICINN for financing his research through the “Juan de la Cierva” post-doctoral program. M. Martín Martínez also wishes to thank the MICINN and the European Social Found for her research gran
Structure sensitivity reaction of chloroform hydrodechlorination to light olefins using Pd catalysts supported on carbon nanotubes and carbon nanofibers
The upgrading of wasted chloroform in hydrodechlorination for the production of olefins such as ethylene and propylene is studied by employing four catalysts (PdCl/CNT, PdCl/CNF, PdN/CNT, and PdN/CNF) prepared by different precursors (PdCl2 and Pd(NO3)2) supported on carbon nanotubes (CNT) or carbon nanofibers (CNF). TEM and EXAFS-XANES results confirm that Pd nanoparticle size increases in the order: PdCl/CNT < PdCl/CNF ∼ PdN/CNT < PdN/CNF, descending the electron density of Pd nanoparticles in the same order. It illustrates that PdCl-based catalysts show donation of electrons from support to Pd nanoparticles, which is not observed in PdN-based catalysts. Moreover, this effect is more evident in CNT. The smallest and well-dispersed Pd nanoparticles (NPs) on PdCl/CNT with high electron density favor an excellent and stable activity and a remarkable selectivity to olefins. In contrast, the other three catalysts show lower selectivity to olefins and lower activities which suffer strong deactivation due to the formation of Pd carbides on their larger Pd nanoparticles with lower electron density, compared to PdCl/CNTThe authors acknowledges FEDER/Ministerio de Ciencia, Innovación
y Universidades – Agencia Estatal de Investigación (CTM2017-85498-R)
and Comunidad de Madrid/UAM (SI1/PJI/2019-00487) for financial
support. The authors acknowledge to ALBA Synchrotron facility for
beamtime at CLAESS (experiment 2016021666-2). Maria Martin Martinez acknowledges a postdoctoral grant (2017-T2/AMB-5668),
from the Comunidad de Madrid “Atracción de Talento” programme.
Sichen Liu acknowledges Ministerio de Ciencia e Innovación for his
research grant (PRE2018-084424
SITUACIÓN ECONÓMICA DE LAS MIPYMES DE ABARROTES EN XALOZTOC, TLAXCALA MÉXICO Y SU CAPITALIZACIÓN
This article describes the realization of a situational analysis of the financial culture and the financing´s sources currently used by MiPyme from the grocery stores sector in the municipality of Xaloztoc, Tlaxcala and a proposal is presented with the alternatives to which they can have access with better conditions, the financing that has high interest costs and a series of requirements to be fulfilled and at the same time the part of the financial culture that the MiPyme of the grocery sector raised since the endogenous and decentralization paradigm of each MiPyme, where the local (territorial) emerges as an alternative for economic growth and social welfare. This analysis was curried out through the application of questionnaires, interviews, detail observation methods in order to obtain truthful and reliable data, which were subsequently analyzed through correlations using the SPSS statistical program which give us results that serve as the basis for granting a proposal appropriate to the conditions of the grocery sector, to help them obtain results that generate a positive impact as a company and a greater use of a monetary resources in order to generate a competitive advantages.En este artículo se describe la realización de un análisis situacional de la cultura financiera y las fuentes de financiamiento utilizadas en la actualidad por las MiPymes del sector de abarrotes en el Municipio de Xaloztoc Tlaxcala y se presenta una propuesta con las alternativas a las que pueden tener acceso con mejores condiciones, el financiamiento que tiene altos costos de interés y una serie de requisitos a cumplir y al mismo tiempo se identifica la parte de cultura financiera de la que carecen las MiPymes del sector de abarrotes planteado desde el paradigma endógeno y de descentralización de cada MiPyme, donde lo local (territorial) emerge como alternativa para el crecimiento económico y el bienestar social. Dicho análisis se llevó a cabo a través de la aplicación de cuestionarios, entrevistas, métodos de observación a detalle con el objetivo de obtener datos veraces y fiables que posteriormente se analizaron mediante correlaciones utilizando el programa estadístico SPSS, lo cual nos arroja resultados que sirven de base para otorgar una propuesta adecuada a las condiciones del sector de abarrotes, que les ayude a obtener resultados que les genere un impacto como empresa positivo y un mayor aprovechamiento de los recursos monetarios con el fin de generar una ventaja competitiva
Modelo de los Cinco Dominios para la evaluación del bienestar animal: caso de un león africano (Panthera leo)
The Five Domains Model is a tool to evaluate the state of animal welfare in captivity through the monitoring of subjective, both negative and positive experiences. There are four physical and functional domains: nutrition, environment, health and behavior; while the fifth domain called mental state is an affective experience. In cases where all domains reach an optimal state, the animal is said to be in good health. In this report, The Five Domains Model was applied to evaluate the management of animal welfare of a resident lion of the Simón Bolívar National Zoological Park and Botanical Garden, Costa Rica, during osteoarthritis treatment received between May and December 2016.El modelo de los cinco dominios es una herramienta que permite evaluar el estado de bienestar animal bajo cuidado humano a través del seguimiento de experiencias subjetivas, negativas y positivas. Existen cuatro dominios atribuidos como físicos y funcionales que son: nutrición, medio ambiente, salud y comportamiento; en tanto que el quinto dominio denominado estado mental, es una experiencia afectiva. En los casos donde todos los dominios alcanzan un estado óptimo se dice que el animal se encuentra con bienestar. En este reporte se aplicó el modelo de los cinco dominios para evaluar el manejo del bienestar animal de un león residente del Parque Zoológico y Jardín Botánico Nacional Simón Bolívar, Costa Rica, durante el tratamiento de osteoartrosis recibido entre mayo a diciembre de 2016
Memoria del III Coloquio Internacional sobre Diversidad Cultural y Estudios Regionales
Del 05 al 07 de noviembre de 2014 se llevó a cabo en la Sede de Occidente de la Universidad de Costa Rica, el III Coloquio Internacional sobre Diversidad Cultural y Estudios Regionales, dicado a Julieta Dobles Izaguirre, Premio Nacional de Cultura Magón, 2013. Este III Coloquio Internacional fue
organizado por el Centro de Investigaciones sobre Diversidad Cultural y Estudios Regionales (CIDICER), primer Centro de Investigaciones de una Sede Regional de la Universidad de Costa Rica. Se contó con personas investigacdoras nacionales e internacionales quienes presentaron sobre temas relacionados
con la diversidad cultural y los estudios regionales.Universidad de Costa Rica/[836-B4-702]/UCR/Costa RicaUCR::Sedes Regionales::Sede de Occidente::Recinto San Ramón::Centro de Investigaciones sobre Diversidad Cultural y Estudios Regionales (CIDICER