Steined Heraldry: About Los Círculos Morados. Memorias I, By Jorge Edwards Valdés

Indexación: Revista UNABEste trabajo es un análisis del libro Los círculos morados. Memorias I, del escritor chileno Jorge Edwards. Se discuten aquí tres aspectos, interrelacionados entre sí: la forma en la que el autor asume el género autobiográfico (qué entiende por este género, por qué lo elige y cómo se construye como sujeto), la reflexión que realiza sobre la autoridad paterna y las élites (el prestigio del dinero) y las alternativas para salir de esos círculos, considerados como opresivos.This work is an analytical study about the book Los círculos morados. Memorias I, from the Chilean writer Jorge Edwards. Three aspects are discussed here, which are interweaved among themselves: the way the author assumes the autobiographical genre (what he understands by this genre, why he chooses it and how he construct himself as a first grammatical person), the reflection he elaborates about paternal authority and the elites (money’s prestige) and the alternatives to withdraw from the oppressive circles.http://revistahumanidades.unab.cl/wp-content/uploads/2014/07/A6.-CANOVAS.pd

Los relatos del origen: judíos en México

Fecha de recepción: 5 de noviembre de 2007. Fecha de aceptación: 31 de octubre de 2008. Se hace una presentación de la literatura judía en México, teniendo presentes los relatos y textos poéticos escritos por los hijos y nietos de los inmigrantes judíos que escriben en español (y excepcionalmente, en inglés). Para la exposición de este corpus singular −de por lo menos catorce autores y una treintena de textos−, se han dispuesto siete entradas de lectura: Sefarad, Holocausto, Memoria y escritura, Kibbutz, Casa patriarcal, Tradición y bastardía y, finalmente, para el material en inglés, In other words. Estos acápites están concebidos como versiones de una misma forma, lo judaico, evidente en diversos registros conceptuales.

Statistical and kinetic study for leaching of covellite in a chloride media

Covellite is a relatively rare copper sulfide with slow dissolution kinetics. The present investigation used the surface optimization methodology to evaluate the effect of three independent variables (time, chloride concentration and sulfuric acid concentration) on the rate of extracting Cu from covellite. The effects of chloride concentration and temperature over time were also studied. An ANOVA indicated that the linear variables of time and chloride concentration have the greatest influence, this being highly representative (R2 = 0.9945). The highest copper extraction rate (71.23%) at room temperature, was obtained with a high chloride concentration (100 g/L), a low concentration of sulfuric acid (0.5 M), and a leaching period of 600 h. The dissolution is described by the model of the unreacted core, the rate of leaching of the covellite is controlled by the chemical surface reaction at temperatures between 50 and 90°C, with concentrations of 0.5 M of H2SO4, 100 g/L of chloride, and a leaching period of up to 6 hours, where an activation energy of 72.36 kJ/mol was obtaine.The authors are grateful for the contribution of the Scientific Equipment Unit-MAINI of the Universidad Católica del Norte for aiding in generating data by automated electronic microscopy QEMSCAN® and for facilitating the chemical analysis of the solutions. We are also grateful to Marina Vargas Aleuy and Carolina Ossandón Cortés of the Universidad Católica del Norte for supporting the experimental tests

Leaching of pure chalcocite in a chloride media using sea water and wastewater

Chalcocite is the most important and abundant secondary copper ore in the world with a rapid dissolution of copper in an acid-chloride environment. In this investigation, the methodology of surface optimization will be applied to evaluate the e_ect of three independent variables (time, concentration of sulfuric acid and chloride concentration) in the leaching of pure chalcocite to extract the copper with the objective of obtaining a quadratic model that allows us to predict the extraction of copper. The kinetics of copper dissolution in regard to the function of temperature is also analyzed. An ANOVA indicates that the linear variables with the greatest influence are time and the chloride concentration. Also, the concentration of chloride-time exerts a significant synergic e_ect in the quadratic model. The ANOVA indicates that the quadratic model is representative and the R2 value of 0.92 is valid. The highest copper extraction (67.75%) was obtained at 48 h leaching under conditions of 2 mol/L H2SO4 and 100 g/L chloride. The XRD analysis shows the formation of a stable and non-polluting residue; such as elemental sulfur (S0). This residue was obtained in a leaching time of 4 h at room temperature under conditions of 0.5 mol/L H2SO4 and 50 g/L Cl.The authors are grateful for the contribution of the Scientific Equipment Unit- MAINI of the Universidad Católica del Norte for aiding in generating data by automated electronic microscopy QEMSCAN® and for facilitating the chemical analysis of the solutions. We are also grateful to the Altonorte Mining Company for supporting this research and providing slag for this study, and we thank to Marina Vargas Aleuy and María Barraza Bustos of the Universidad Católica del Norte for supporting the experimental tests