Synthesis and characterization of analcime (ANA) zeolite using a kaolinitic rock

Analcime is nowadays an important component in dental porcelain systems, in heterogeneous catalysis, in the nanoelectronic feld, in selective adsorption and in stomatology (dental flling and prosthesis). Analcime synthesis from an impure, silica-rich kaolinite rock coming from Romana (Sassari, Italy) is here presented. A synthesis protocol is proposed that aims to make an improvement of synthesis conditions compared to the past. The hydrothermal treatment is in fact here achieved without aging times and without the use of sodium silicate or other additional silica source reported in the literature. Lower calcination temperature, synthesis temperature and crystallization time are verifed in this work. The kaolin is subjected to calcination at the temperature of 650 °C and then mixed with NaOH. The experiment is performed at ambient pressure and 170± 0.1 °C. The degree of purity of analcime is calculated in 97.57% at 10 h. Analcime is characterized by X-ray difraction, infrared spectroscopy, scanning electron microscopy, inductively coupled plasma optical emission spectrometry and thermal analysis. Density is also calculated. Cell parameters and the amount of amorphous phase in the synthesis powders is estimated with quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. The experimental conditions make the synthesis protocol particularly attractive from an economic point of view. Also this work does not use a commercial kaolin but silica-rich impure kaolinitic rock from a disused quarry. This further reduces the costs of the experimental protocol. It also gives the protocol an added value, as the synthesis of a useful mineral is obtained through the valorization of an otherwise unused georesource. Both chemical and physical characterization of analcime is satisfactory making the experimental protocol very promising for an industrial transfe

Prison de-radicalization strategies, programmes and risk assessment tools

This project\u2019s goal is to assess strategies and programmes which prevent, deter and counter radicalization in prison and identify and analyse good practices regarding new or existing de-radicalization, disengagement and rehabilitation programmes and risk assessment tools. The analysis has been carried out having in mind the international and European standards for the the protection of detainees' rights. Research incorporates qualitative and quantitative data analysis on official government documents and interviews with stakeholders from prison administration and management, prison staff, Imams, chaplains and other religious representatives

Teoría y política económica. Ensayos en honor al profesor Dr. Julio H. G. Olivera

Al tomar conocimiento de la publicación de esta obra fue muy gratificante saber que un grupo de destacados economistas de nuestro país, habiendo recibido la influencia y el legado de un gran exponente del pensamiento económico argentino, como lo fue el Dr. Julio Olivera, decidieron aportar a la escritura de un texto que compila el resultado de un trabajo fructífero en materia de producción científica, como forma de rendir un homenaje a su memoria. La compilación, desde diferentes temas económicos y pluralismo ideológico, aborda cuestiones que se agrupan en cuatro partes cuyos ejes estructurantes incluyen aspectos, tanto metodológicos como disciplinares, que hacen a la particularidad de la ciencia económica.</p

Teoría y política económica. Ensayos en honor al profesor Dr. Julio H. G. Olivera

Al tomar conocimiento de la publicación de esta obra fue muy gratificante saber que un grupo de destacados economistas de nuestro país, habiendo recibido la influencia y el legado de un gran exponente del pensamiento económico argentino, como lo fue el Dr. Julio Olivera, decidieron aportar a la escritura de un texto que compila el resultado de un trabajo fructífero en materia de producción científica, como forma de rendir un homenaje a su memoria. La compilación, desde diferentes temas económicos y pluralismo ideológico, aborda cuestiones que se agrupan en cuatro partes cuyos ejes estructurantes incluyen aspectos, tanto metodológicos como disciplinares, que hacen a la particularidad de la ciencia económica

Synthesis and characterization of wollastonite-2M by using a diatomite precursor

Solid phase reaction synthesis of wollastonite-2M by a natural rock precursor as the source of amorphous silica and CaCO3 is reported. Chemical treatments were carried out on a diatomitic rock from Crotone (Calabria, Italy) in order to measure its reactive silica and CaCO3 contents. Four series of synthesis were performed at 1000°C at ambient pressure by mixing, at different stoichiometry, the diatomitic rock with a natural limestone as a source of additive CaCO3, and sodium carbonate (Na2CO3) as triggering agent. Wollastonite-2M was characterized by chemo-physical, crystallographical and morphological-microtextural analyses. All these characterizations, together with infrared and nuclear magnetic resonance (29Si) responses provide values comparable to literature data. Estimation of the amorphous phase in the synthesis powders was performed through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods, resulting in a final product of 96.3% wollastonite-2M

Synthesis and characterization of Leucite using a diatomite precursor

Leucite is nowadays an important component in ceramic restoration systems with particular suitability to dental porcelains. The leucite synthesis from a hydrothermally-derived precursor is here presented. A silicate solution was prepared by mixing a naturally derived amorphous silica (diatomitic rock from Crotone, southern Italy) with potassium hydroxide and an aluminate solution was obtained by mixing aluminium hydroxide and potassium hydroxide. Three mixtures of varying ratios of aluminate and silicate solutions were prepared and submitted to hydrothermal treatment at 150 °C for one hour. Subsequently these hydrothermal precursors were subjected to calcination at the temperature of 1000 °C for variable time intervals, thus resulting in 3 series of syntheses. The synthesis run 3 turned out to be the best from the point of view of temporal yield showing the crystallization of the leucite after only 15 hours of heat treatment. The products of synthesis run 3 were fully characterised by Powder X-Ray Diffraction, Inductively Coupled Plasma Optical Emission Spectrometry, Infrared Spectroscopy and Thermal Analysis. The amorphous phase in the synthesis powders was estimated by quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. Density of leucite was also achieved by He-pycnometry. The use of a cost effective starting material such as a diatomite in the experimental route makes the process highly attractive for expansion to an industrial scale especially considering that both the chemical and physical characterizations of our leucite product are highly satisfactory. Last but not least we explain some inferences that can be obtained from this process of synthesis in order to a better understanding of some natural occurrences of leucite in geologic systems related to basaltic magmas

Diseño curricular y extensión: la incorporación de un espacio dedicado al aprendizaje en servicios en la licenciatura en economía

El trabajo consiste en una breve descripción de los aspectos tenidos en cuenta durante un proceso de cambio de plan de estudios de la Licenciatura en Economía, carrera de grado que se dicta en la Facultad de Ciencias Económicas (FCE) de la Universidad Nacional del Nordeste (UNNE), que incorporó en el nuevo diseño curricular, actividades de ex tensión obligatorias a ser desarrolladas por los estudiantes. El trabajo realizado por la comisión de cambio curricular tomó en con sideración la normativa vigente y el asesoramiento de profesionales con formación en procesos de cambio curricular, estas cuestiones se sintetizan en el artículo haciendo hincapié y profundizando en el análisis crítico del plan modificado. El nuevo plan ha incorporado un espacio curricular denominado práctica profesional basada en servicios. Es un espacio de una carga de 54 horas presenciales, cuya definición e incorporación al plan se ha realizado en base a una alternativa cuya definición e implementación costó acordar.

Synthesis and characterization of Na‑P1 (GIS) zeolite using a kaolinitic rock

This work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. The results make the experimental protocol very promising for an industrial transfer

Análisis del fondo para el desarrollo del empleo industrial de la Provincia del Chaco

El presente trabajo toma como objeto de estudio el análisis de un ejemplo de política pública plasmada en una ley, a efectos de analizarla y determinar los alcances de la misma, sus posibles efectos sobre la actividad económica y los límites que enfrenta. La medida analizada es el Fondo para el Desarrollo del Empleo Industrial, creado por Ley 6621 del año 2010 de la Provincia de Chaco, ley que fue reglamentada por el Decreto 956 de mayo del 2011 que creó el FODEI (Fondo para el Desarrollo del Empleo Industrial) y por la Resolución Ministerial 976 de Setiembre del 2011. El trabajo se completa con el marco histórico y económico en el que se lleva a cabo la sanción de la ley. El análisis y las conclusiones elaborados toman los conceptos y argumentos teóricos que permiten el estudio del diseño y la dinámica de las políticas públicas, así como, la importancia de su implementación efectiva para la concreción de determinados objetivos socioeconómicos.