Violencia e invisibilidad indígena : La cuestión de los pueblos originarios durante el primer peronismo

El presente trabajo busca profundizar en el análisis de los vínculos existentes entre el primer gobierno peronista y la cuestión indígena, centrándose en las políticas gubernamentales desarrolladas por el gobierno de Perón frente a dos fuertes conflictos violentos que tuvieron lugar entre 1946 y 1947: el "Malón de la paz", la movilización indígena llevada a cabo entre mayo y agosto de 1947, cuando 174 kollas caminaron 2000 kilómetros desde la Puna y el valle de Orán hasta la Capital Federal para reclamar por la titularidad de sus tierras, en manos de terratenientes y en denuncia de las condiciones de explotación en las que trabajaban; y "Masacre de Rincón Bomba", el conflicto desarrollado en una pequeña localidad de Formosa, cuando indígenas de comunidades wichi, tobas y principalmente pilagás fueron masacradas por la Gendarmería Nacional en un confuso episodio, que sale a la luz hace pocos años. El objetivo en ambos puntos es doble: por un lado analizar la relación entre los intereses e intenciones del gobierno de Juan Domingo Perón para con las comunidades originarias, visibilizando su existencia y sus condiciones de vida en tanto sujetos de derechos históricamente vulnerados. Por otro, abrir el debate historiográfico sobre el quehacer de los historiadores respecto de una temática que ha sido silenciada durante décadas, negando la existencia y la identidad de los pueblos originarios

Dossier : Pueblos indígenas latinoamericanos: historias de lucha, memorias de resistencia

Fil: Rosas, Sabrina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Microsociología del estigma: el papel de las leyendas contemporáneas en la construcción social del VIH y el SIDA en la República Dominicana

El estigma social, entendido como “un atributo profundamente desacreditador” (Goffman, 1963/1986), ha sido reconocido como un elemento que “contribuye dramáticamente a la expansión de la epidemia” (De Moya et al., 1998a) del VIH en la República Dominicana, impactando negativamente tanto la Respuesta Nacional como la calidad de vida de personas que viven con esta condición de salud. Estudios previos (Miric, 2005) sugieren el análisis de leyendas contemporáneas como un elemento clave para la comprensión del estigma social vinculado al VIH y al SIDA y de los mecanismos a través de los cuales este fenómeno se construye y se mantiene en la sociedad Dominicana. Partiendo de lo anterior, se llevó a cabo un estudio observacional, descriptivo y transversal, enfocado en el análisis de las leyendas contemporáneas sobre el VIH y al SIDA y su relación con el fenómeno de estigma social vinculado a esta condición de salud en la República Dominicana desde una perspectiva microsociológica. El estudio se fundamenta en el concepto de marcos organizativos de Erving Goffman (1974) y su trabajo pionero en la conceptualización del estigma social, como un enfoque teórico fértil y, a la vez, poco explorado en el análisis del papel desempeñado por las leyendas contemporáneas en la construcción social del VIH y el SIDA en la sociedad dominicana...

Electrooxidation methods to produce pseudocapacitance-containing porous carbons

Surface oxygen groups play a key role on the performance of porous carbon electrodes for electrochemical capacitors in aqueous media. The electrooxidation method in NaCl electrolyte using a filter press cell and dimensionally stable anodes is proposed as a viable process for the generation of oxygen groups on porous carbon materials. The experimental set-up is so flexible that allows the easy modification of carbon materials with different configurations, i.e. cloths and granular, obtaining different degrees of oxidation for both conformations without the requirement of binders and conductivity promoters. After the electrooxidation method, the attained porosity is maintained between 90 and 75% of the initial values. The surface oxygen groups generated can increase the capacitance up to a 30% when compared to the pristine material. However, a severe oxidation is detrimental since it may decrease the conductivity and increase the resistance for ion mobility.

Carbon–carbon asymmetric aqueous capacitor by pseudocapacitive positive and stable negative electrodes

An asymmetric aqueous capacitor was constructed by employing zeolite-templated carbon (ZTC) as a pseudocapacitive positive electrode and KOH-activated carbon as a stable negative electrode. The asymmetric capacitor can be operated with the working voltage of 1.4 V, and exhibits an energy density that is comparable to those of conventional capacitors utilizing organic electrolytes, thanks to the large pseudocapacitance of ZTC. Despite relatively thick electrode (0.2 mm) configuration, the asymmetric capacitor could be well operated under a current density of 500 mA g −1.

Preparation of homogeneous CNT coatings in insulating capillary tubes by an innovative electrochemically-assisted method

Preparation of homogeneous CNT coatings in insulating silica capillary tubes is carried out by an innovative electrochemically-assisted method in which the driving force for the deposition is the change in pH inside the confined space between the inner electrode and the capillary walls. This method represents a great advancement in the development of CNT coatings following a simple, cost-effective methodology.

Binderless thin films of zeolite-templated carbon electrodes useful for electrochemical microcapacitors with ultrahigh rate performance

Controlled nanozeolite deposits are prepared by electrochemical techniques on a macroporous carbon support and binderless thin film electrodes of zeolite-templated carbon are synthesized using the deposits as templates. The obtained film electrodes exhibit extremely high area capacitance (10–12 mF cm−2) and ultrahigh rate capability in a thin film capacitor.

Electroadsorption of arsenic from natural water in granular activated carbon

The adsorption and electroadsorption of arsenic from a natural water has been studied in a filter-press electrochemical cell using a commercial granular activated carbon as adsorbent and Pt/Ti and graphite as electrodes. A significant reduction of the arsenic concentration is achieved when current is imposed between the electrodes, especially when the activated carbon was located in the vicinity of the anode. This enhancement can be explained in terms of the presence of electrostatic interactions between the polarized carbon surface and the arsenic ions, and changes in the distribution of most stable species of arsenic in solution due to As(III) to As(V) oxidation. In summary, electrochemical adsorption on a filter-press cell can be used for enhancement the arsenic remediation with activated carbon in the treatment of a real groundwater.

On the origin of the high capacitance of nitrogen-containing carbon nanotubes in acidic and alkaline electrolytes

The synthesis of nitrogenated carbon nanotubes (N-CNTs) with up to 6.1 wt% N, via the use of pyridine as the nitrogen containing carbon precursor, can provide a facile route to significantly enhance the low intrinsic specific capacitance of carbon nanotubes. The nitrogen functionalities determine this, at least, five-fold increase of the specific capacitance.

Methoxylation of α-pinene over mesoporous carbons and microporous carbons: A comparative study

A biomass derived carbon, a commercial microporous carbon and a xerogel mesoporous carbon catalysts were used in the study of α-pinene methoxilation reaction and the influence of textural and physical–chemical properties of the carbons was evaluated. Biomass carbon presented the higher activity, whereas the commercial one is the less active in the conditions studied. The main product of the reaction was α-terpinyl methyl ether and good values of selectivity were obtained over all the catalysts. A kinetic model was developed assuming that the α-pinene is consumed according to the parallel reaction network. The kinetic model presents high quality fittings to the experimental concentration profiles. These results show that it is possible to activate a waste residue using H3PO4 and convert it to high added value product such as acid catalyst.

Electrospinning of silica sub-microtubes mats with platinum nanoparticles for NO catalytic reduction

Silica sub-microtubes loaded with platinum nanoparticles have been prepared in flexible non-woven mats using co-axial electrospinning technique. A partially gelated sol made from tetraethyl orthosilicate was used as the silica precursor, and oil was used as the sacrificial template for the hollow channel generation. Platinum has been supported on the wall of the tubes just adding the metallic precursor to the sol–gel, thus obtaining the supported catalyst by one-pot method. The silica tubes have a high aspect ratio with external/internal diameters of 400/200 nm and well-dispersed platinum nanoparticles of around 2 nm. This catalyst showed a high NO conversion with very high selectivity to N2 at mild conditions in the presence of excess oxygen when using C3H6 as reducing agent. This relevant result reveals the potential of this technique to produce nanostructured catalysts onto easy to handle conformations.

Tailoring the Surface Chemistry of Activated Carbon Cloth by Electrochemical Methods

This paper presents a systematic study of the effect of the electrochemical treatment (galvanostatic electrolysis in a filter-press electrochemical cell) on the surface chemistry and porous texture of commercial activated carbon cloth. The same treatments have been conducted over a granular activated carbon in order to clarify the effect of morphology. The influence of different electrochemical variables, such as the electrode polarity (anodic or cathodic), the applied current (between 0.2 and 1.0 A) and the type of electrolyte (HNO3 and NaCl) have also been analyzed. The anodic treatment of both activated carbons causes an increase in the amount of surface oxygen groups, whereas the cathodic treatment does not produce any relevant modification of the surface chemistry. The HNO3 electrolyte produced a lower generation of oxygen groups than the NaCl one, but differences in the achieved distribution of surface groups can be benefitial to selectively tune the surface chemistry. The porous texture seems to be unaltered after the electro-oxidation treatment. The validity of this method to introduce surface oxygen groups with a pseudocapacitive behavior has been corroborated by cyclic voltammetry. As a conclusion, the electrochemical treatment can be easily implemented to selectively and quantitatively modify the surface chemistry of activated carbons with different shapes and morphologies.