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Origen de la mineralización y alteración hidrotermal del depósito tipo IOCG Diego de Almagro, III región de Atacama, Chile
(Universidad de Chile, 2016)
mejor comprensión de los procesos de alteración y mineralización que dieron paso a la formación de este yacimiento, y así aportar nuevos antecedentes para establecer un modelo geológico y genético del depósito en el contexto de la Franja Andina de IOCG...
Procesos de Meteorización en Condritos Ordinarios del Desierto de Atacama, Norte de Chile: Nuevos Antecedentes sobre Meteorización de Material Extraterrestre en Ambientes Desérticos
(Universidad de ChileCyberDocs, 2011)
Una completa caracterización de los condritos ordinarios (CO’s) del desierto de Atacama, II región, Chile, fue realizada en el marco de esta tesis doctoral, provenientes de 2 localidades: Pampa de Mejillones (PM), en la zona costera y San Juan (SJ...
Síntesis de carbazol-tio- y aminoquinonas antitumorales
(Universidad de Chile, 2013-09)
caminos,
caminos sobre la mar.
Nunca perseguí la gloria,
ni dejar en la memoria
de los hombres mi canción;
yo amo los mundos sutiles,
ingrávidos y gentiles,
como pompas de jabón.
Me gusta verlos pintarse
de sol y grana, volar
bajo...
grupo de investigación13 estudió la actividad antifúngica de quinonas e hidroquinonas tricíclicas frente a B. cinerea, encontrándose actividades similares a productos comerciales como la iprodiona (fungicida). El estudio reveló que las quinonas actúan...
grupo de investigación13 estudió la actividad antifúngica de quinonas e hidroquinonas tricíclicas frente a B. cinerea, encontrándose actividades similares a productos comerciales como la iprodiona (fungicida). El estudio reveló que las quinonas actúan...
Determinación de zonas homogéneas en la región del Bío-Bío, Chile, para estimar caudales disponibles para dilución en cuencas sin control fluviométrico
(Universidad de Chile, 2018)
El caudal disponible para dilución es aquel que limita la cantidad de caudal vertido en un cuerpo de agua con la finalidad de no dañar el ecosistema aguas abajo. En el DS 90/2000 del Ministerio Secretaría General de la Presidencia, este caudal se...
Evolución geoquímica del magmatismo de la Región de Los Pelambres (31°S) entre el cretácico superior y el mioceno superior: implicancias para la evolución tectónica y metalogénica de los Andes de Chile Central
(Universidad de Chile, 2016)
La Región de Los Pelambres (31°15 32°7 S y 70°15 70°48 O) se encuentra ubicada en la zona central de la región de subducción plana de los Andes centrales de Chile y Argentina y abarca un registro geológico que va desde el Paleozoico superior...
Optimización de la configuración y calendarización del proceso por lotes de planta elaboradora de producto biotecnológico
(Universidad de Chile, 2020)
parte, la necesidad vital de recursos, rutas de reacción alternativas, procesos
químicos industriales amigables con el medio ambiente y económicamente viables, se ha
convertido en una realidad ubicua [1]. En este sentido, el proceso basado en...
. Finalmente, el grado de certeza sobre el valor de los parámetros críticos del proceso podrá ser determinístico o estocástico [4]. 2.2. El problema de la calendarización Los procesos por lotes se diferencian de los procesos continuos principalmente en que el...
. Finalmente, el grado de certeza sobre el valor de los parámetros críticos del proceso podrá ser determinístico o estocástico [4]. 2.2. El problema de la calendarización Los procesos por lotes se diferencian de los procesos continuos principalmente en que el...
Origen y naturaleza de los fluidos de los sistemas volcánicos e hidrotermales activos de los Andes de Chile central (32.5-36°S)
(Universidad de Chile, 2015)
con fluidos de origen meteórico. Las razones de N2/Ar (<1500) y R/Ra (<7.11), al igual que la composición isotópica de H2OV de las descargas fumarólicas relaciona directamente el origen de dichos fluidos con la deshidratación del slab y la consecuente...
Diseño de un procedimiento para la separación de los iones tierras raras lantano(III), cerio(III), praseodimio(III) y neodimio(III) mediante membranas líquidas emulsificadas utilizando como agentes transportadores extractantes organofosforados
(Universidad de Chile, 2013)
membranas líquidas emulsificadas, utilizando extractantes organofosforados como agentes transportadores. Se busca que en cada etapa se provoque la separación de cada elemento, favoreciendo su extracción hacia la fase membrana y/o hacia la fase acuosa interna...
This Thesis proposes a separation route for the lanthanide metal ions, lanthanum (III), cerium (III), praseodymium (III) and neodymium (III), from a sample treat simulates the approximate concentrations of a leaching solution of bastnaesite, by means of Emulsified Liquid Membranes using organophosphorus extractants as transport agents. The purpose is to achieve the separation of each element by their extraction into the membrane phase and/or to the internal aqueous phase or eventually remained mostly in the raffinate. By means of a kinetic study of extraction for all lanthanide elements contained into the feed aqueous phase it was determined that the optimal time for extracting and transferring the elements is 15 minutes, because from this time the maximum extraction and transfer percentages are achieved. Firstly, we conducted a study of extraction behavior of all possible pairs of lanthanide elements, formed between lanthanum, cerium, praseodymium and neodymium, in order to propose a possible route of separation for them by means of Emulsified Liquid Membrane methodology. In this study, the concentration of the CYANEX 272 carrier was varied between 1.25 and 5 mM, bufferized at pH 4 with 3-chloropropionic acid 0.2 M. Under these working conditions it was determined that after three stages of contact an aqueous solution rich in lanthanum having a purity of 86.5% and a yield of 27.9% is obtained. However, the analysis of the extraction through the distribution coefficients, obtained from the extraction study of lanthanide pairs, indicated that a lanthanum solution almost purity of 100% with a yield of 49.1 is obtained. These differences in results are due to that the extraction steps projection requires readjustment of operational conditions on the raffinate to the initial conditions on the feed solution. Secondly, a solution containing cerium, praseodymium and neodymium, based on the assumption that the lanthanum was completely removed, was used as feed solution. Due to in the previous experimental conditions it was not possible to separate one of these three elements it was decided to add hydrogen peroxide as oxidizing agent to the feed solution, in order to cause the change of the oxidation state in the cerium element from 3+ to 4+. Additionally, this modification considered the decreasing of the initial pH value from 4 to 2.5, since it is not possible to have the Ce4+ ions in aqueous solution at pH higher than 3, because it is precipitated as hydroxide. Furthermore, it is known that the extraction of the Ce4+ ions is low and those of praseodymium and neodymium 3+ ions are deficient with the extractant CYANEX 272. For this reason, the extractant D2EHPA from the same organophosphorus family but of higher strength binder, was chosen. At these working conditions, by a projection of this result, is necessary to make two contact steps of the feed solution containing Ce4+, Pr3+ and Nd3+ with a primary emulsion for obtaining a cerium-rich raffinate, with a purity around 100% and a 33.3% yield. Once the separations of lanthanum and cerium from solutions containing the four lanthanide elements are achieved, the study was focused on the separation of the praseodymium/neodymium pair of elements using two alternatives: one of them include complexing or masking agents contained in aqueous solution and, the other, one synergistic agent in the membrane phase. The obtained results indicated that the addition of complexing agents, such as I-, SCN-, citrate and imidazole have not significant effect on the separation of the two elements, while the inclusion of TBP and TOPO as synergistic agents generated, in the best cases, a separation coefficient in the internal aqueous phase for neodymium/praseodymium of 0.84, when 100 mM of TBP is used. By means of a analysis of this separation coefficient, was established that it is necessary to make five contact steps of the feed solution with a primary emulsion, where the praseodymium is concentrated in the inner aqueous phase and neodymium remains in the organic phase, for giving a rich-praseodymium aqueous solution having near 100% purity and a 5.6% yield. Although in some cases the yields are low, the capacity for waste reprocessing is easy to perform in a simple and direct way. For this reason the method has great potential for application in the separation of these lanthanide elements by means of emulsified liquid membranes using the organophosphorus family as carrier...
This Thesis proposes a separation route for the lanthanide metal ions, lanthanum (III), cerium (III), praseodymium (III) and neodymium (III), from a sample treat simulates the approximate concentrations of a leaching solution of bastnaesite, by means of Emulsified Liquid Membranes using organophosphorus extractants as transport agents. The purpose is to achieve the separation of each element by their extraction into the membrane phase and/or to the internal aqueous phase or eventually remained mostly in the raffinate. By means of a kinetic study of extraction for all lanthanide elements contained into the feed aqueous phase it was determined that the optimal time for extracting and transferring the elements is 15 minutes, because from this time the maximum extraction and transfer percentages are achieved. Firstly, we conducted a study of extraction behavior of all possible pairs of lanthanide elements, formed between lanthanum, cerium, praseodymium and neodymium, in order to propose a possible route of separation for them by means of Emulsified Liquid Membrane methodology. In this study, the concentration of the CYANEX 272 carrier was varied between 1.25 and 5 mM, bufferized at pH 4 with 3-chloropropionic acid 0.2 M. Under these working conditions it was determined that after three stages of contact an aqueous solution rich in lanthanum having a purity of 86.5% and a yield of 27.9% is obtained. However, the analysis of the extraction through the distribution coefficients, obtained from the extraction study of lanthanide pairs, indicated that a lanthanum solution almost purity of 100% with a yield of 49.1 is obtained. These differences in results are due to that the extraction steps projection requires readjustment of operational conditions on the raffinate to the initial conditions on the feed solution. Secondly, a solution containing cerium, praseodymium and neodymium, based on the assumption that the lanthanum was completely removed, was used as feed solution. Due to in the previous experimental conditions it was not possible to separate one of these three elements it was decided to add hydrogen peroxide as oxidizing agent to the feed solution, in order to cause the change of the oxidation state in the cerium element from 3+ to 4+. Additionally, this modification considered the decreasing of the initial pH value from 4 to 2.5, since it is not possible to have the Ce4+ ions in aqueous solution at pH higher than 3, because it is precipitated as hydroxide. Furthermore, it is known that the extraction of the Ce4+ ions is low and those of praseodymium and neodymium 3+ ions are deficient with the extractant CYANEX 272. For this reason, the extractant D2EHPA from the same organophosphorus family but of higher strength binder, was chosen. At these working conditions, by a projection of this result, is necessary to make two contact steps of the feed solution containing Ce4+, Pr3+ and Nd3+ with a primary emulsion for obtaining a cerium-rich raffinate, with a purity around 100% and a 33.3% yield. Once the separations of lanthanum and cerium from solutions containing the four lanthanide elements are achieved, the study was focused on the separation of the praseodymium/neodymium pair of elements using two alternatives: one of them include complexing or masking agents contained in aqueous solution and, the other, one synergistic agent in the membrane phase. The obtained results indicated that the addition of complexing agents, such as I-, SCN-, citrate and imidazole have not significant effect on the separation of the two elements, while the inclusion of TBP and TOPO as synergistic agents generated, in the best cases, a separation coefficient in the internal aqueous phase for neodymium/praseodymium of 0.84, when 100 mM of TBP is used. By means of a analysis of this separation coefficient, was established that it is necessary to make five contact steps of the feed solution with a primary emulsion, where the praseodymium is concentrated in the inner aqueous phase and neodymium remains in the organic phase, for giving a rich-praseodymium aqueous solution having near 100% purity and a 5.6% yield. Although in some cases the yields are low, the capacity for waste reprocessing is easy to perform in a simple and direct way. For this reason the method has great potential for application in the separation of these lanthanide elements by means of emulsified liquid membranes using the organophosphorus family as carrier...
Descripción de registros clínicos de perros y gatos con infecciones del tracto urinario (ITU)
(Universidad de Chile, 2014)
Se seleccionaron 48 fichas, de pacientes con urocultivos positivos y con sus respectivos antibiogramas, desde la casuística atendida en el Hospital Veterinario de Alta Complejidad sede Bilbao de la Universidad de Chile, en el período de enero del...
Validación prospectiva del proceso de fabricación de un antipsicótico oral en comprimidos de liberación convencional
(Universidad de Chile, 2016)
) y el sistema de agua. El sistema HVAC permite la protección del producto a través de la prevención de la contaminación y contaminación cruzada, mientras que al evitar la eliminación de polvo se protege al ambiente y también se previene el contacto de...
PRÁCTICA PROLONGADA PARA OPTAR AL TÍTULO DE QUÍMICO FARMACÉUTICO DANNISSA VILLALOBOS ABARZÚA SANTIAGO DE CHILE 2016 MONITOR DE PRÁCTICA Q.F. Marcos Morales Urzúa Gerente de Investigación y Desarrollo Laboratorio Synthon Chile PROFESOR...
PRÁCTICA PROLONGADA PARA OPTAR AL TÍTULO DE QUÍMICO FARMACÉUTICO DANNISSA VILLALOBOS ABARZÚA SANTIAGO DE CHILE 2016 MONITOR DE PRÁCTICA Q.F. Marcos Morales Urzúa Gerente de Investigación y Desarrollo Laboratorio Synthon Chile PROFESOR...