Efeito da adição de feldspato e/ou resíduo de caulin em formulações à base de argila ilítica

The red pottery industry in Piauí state is well developed and stands out at the national context for the technical quality of its products. The floor and wall tile industry, however, is little developed since the state has only one company that produces red clay-based ceramic tiles. This thesis aims at using the predominantly illitic basic mass of the above mentioned industry, with the addition of feldspar and/or kaolin residue in order to obtain products of higher technical quality. Kaolin residue consists basically of kaolinite, muscovite mica and quartz; the feldspar used was potassic. In this experiment, basic mass (MB) was used for experimental control and fifteen formulations codified as follows: F2, F4, F8, F16, F32, FR2, FR4, FR8, FR16, FR32, R2, R4, R8, R16 and R32. All raw materials were dry-milled, classified, formulated and then humidified to 10% water. Thereafter, test samples were produced by unixial pressing process in a rectangular steel matrix (60.0 x 20.0 x 5.0) mm3 at (25 MPa). They were fired at four temperatures: 1080°C, 1120°C, 1160°C, with a heating rate of 10°C/min during up to 10 min in an electric oven, and the last one in an industrial oven with a peak of 1140°C, aim ing to confirm the results found in laboratory and, finally, technological tests were performed: MEA, RL, AA, PA, TRF and PF. The results revealed that the residue under study can be considered a raw material with large potential in the industry of red clay-based ceramic tiles, since the results found both in laboratory and in the industry have shown that the test samples produced from the formulations with up to 4% feldspar and those produced with up to 8% feldspar and residue permitted a reduction in the water absorption rate and an increase in the mechanical resistance while those samples produced with up to 4% residue had an increase in the mechanical resistance when compared to those produced from the basic mass and that the formulation with 2% feldspar and residue presented the best technological properties, lowering the sintering temperature down to 1120°C

Novaja drama e Teatr Praktika: uno sguardo al teatro russo contemporaneo. Proposta di traduzione della piéce di Natalija Mošina "Žara"

Questa tesi si pone come scopo quello di studiare la scena teatrale contemporanea russa, utilizzando come pretesto la traduzione della piéce “Žara” dell’autrice Natalija Mošina. Mošina fa parte del movimento teatrale chiamato ‘novaja drama’, che si è sviluppato in Russia a partire da fine anni Novanta. Nel primo capitolo tratteremo brevemente la storia del teatro russo del Novecento, per osservare come si è giunti alla formazione di questo nuovo movimento. Passeremo poi ad analizzare il movimento vero e proprio, concentrandoci sulle posizioni artistiche dei suoi membri e sul tipo di innovazione che vogliono portare al teatro russo. Proporremo poi una selezione dei luoghi che rinnovano la scena teatrale moscovita. Il secondo capitolo è interamente dedicato ad uno di questi luoghi, il Teatr Praktika, primo teatro statale ad occuparsi esclusivamente di testi contemporanei, di cui vedremo la storia dalla sua fondazione ai giorni nostri e analizzeremo il repertorio vedendo come gli spettacoli messi qui in scena riflettano le posizioni del novaja drama. Nel capitolo conclusivo parleremo più approfonditamente della pièce da noi tradotta vedendo come si colloca all’interno della produzione dell’autrice e del novaja drama, analizzandone la messa in scena al Praktika. Proporremo poi delle riflessioni sulla traduzione di testi teatrali facendo riferimento alla traduzione da noi svolta, che proporremo di seguito.

Los Yacimientos de Arcillas de la Isla de Bioko. Caracterización y Aplicaciones Tecnológicas.

Las recientes investigaciones realizadas en los potentes yacimientos de arcillas que se encuentran en la Ciudad de Malabo (Bioko Norte), República de Guinea Ecuatorial, revelaron la presencia mayoritaria de una fase compuesta por sepiolita, acompañada por especies secundarias de feldespato, caolinita, hematita, moscovita e illita. Los análisis por microscopía electrónica de barrido (MEB), difracción de rayos x (DRX) y agregado orientado con etilenglicol (AO), indican un comportamiento similar y homogéneo de la composición de las muestras estudiadas. Por otro lado, los análisis químicos, puzolanicidad, granulometría (tamizado en seco), consistencia, tiempo de inicio y final de fraguado y la determinación de la estabilidad de volumen, confirman la idoneidad de estas arcillas sepiolíticas no expansivas para sustituir hasta un 25% del cemento portland en los proyectos de mezclas de morteros. No se tiene noticia sobre la realización de proyectos de investigación en estas formaciones sedimentarias, por lo que se considera el primer trabajo de carácter científico que se inicia para la caracterización, sistematización y posibles aplicaciones de estas arcillas en la aún incipiente industria de la construcción ecuatoguineana.

Los Yacimientos Ecuatoguineanos de Arenas Silíceas. Caracterización y Establecimiento de sus Posibles Usos.

Dentro de la amplia diversidad de rocas y minerales industriales que yacen en la República de Guinea Ecuatorial se encuentran los yacimientos e indicios de arenas silíceas de Bioko Norte. Las escasas crónicas mencionan actividades de explotación esporádica y temporera en tres pequeñas cortas, actualmente paralizadas, que se ubican en la aldea de El Cacahual, aproximadamente al suroeste de la ciudad de Malabo, destinadas a la fabricación de morteros para pequeñas construcciones locales. Sin embargo, no se registran estudios sobre la composición y la calidad tecnológica de estos materiales. Los recientes trabajos de investigación llevados a cabo por investigadores de la Escuela de Minas de Madrid y la Universidad de Moa (Cuba), con la colaboración de profesores de la Universidad Nacional de Guinea Ecuatorial, y cuyos resultados se ofrecen en estas líneas, incluyeron campaña de muestreo, caracterización y aplicaciones de estos materiales. Las primeras conclusiones establecen que en la composición sustancial de estos yacimientos aparece el cuarzo como principal fase mineral, acompañado por feldespato, caolinita, mica moscovita e illita (DRX). El estudio morfológico de las muestras por medio de la microscopía electrónica de barrido (MEB) permitió describir granos con dimensiones muy cercanas y con formas angulosas, subangulosas y ocasionalmente subredondeadas, que indican un transporte escaso o casi nulo; esta evidencia infiere la naturaleza residual de estos yacimientos, formados a partir de la alteración y posterior redeposición eluvial de un supuesto protolito de composición granitoide. Por otra parte, la presencia de fases representadas por dolomita y hematita podrían ser el testimonio de la acción de procesos hidrotermales que afectaron a estas formaciones. Otras tareas que complementaron esta investigación, como el estudio granulométrico, contenido en materia orgánica y ensayos de resistencias mecánicas, que fueron realizadas por el Laboratorio Oficial para Ensayos de Materiales de Construcción (LOEMCO), corroboran la calidad tecnológica de estas arenas.

Efeito da adição de feldspato e/ou resíduo de caulin em formulações à base de argila ilítica

The red pottery industry in Piauí state is well developed and stands out at the national context for the technical quality of its products. The floor and wall tile industry, however, is little developed since the state has only one company that produces red clay-based ceramic tiles. This thesis aims at using the predominantly illitic basic mass of the above mentioned industry, with the addition of feldspar and/or kaolin residue in order to obtain products of higher technical quality. Kaolin residue consists basically of kaolinite, muscovite mica and quartz; the feldspar used was potassic. In this experiment, basic mass (MB) was used for experimental control and fifteen formulations codified as follows: F2, F4, F8, F16, F32, FR2, FR4, FR8, FR16, FR32, R2, R4, R8, R16 and R32. All raw materials were dry-milled, classified, formulated and then humidified to 10% water. Thereafter, test samples were produced by unixial pressing process in a rectangular steel matrix (60.0 x 20.0 x 5.0) mm3 at (25 MPa). They were fired at four temperatures: 1080°C, 1120°C, 1160°C, with a heating rate of 10°C/min during up to 10 min in an electric oven, and the last one in an industrial oven with a peak of 1140°C, aim ing to confirm the results found in laboratory and, finally, technological tests were performed: MEA, RL, AA, PA, TRF and PF. The results revealed that the residue under study can be considered a raw material with large potential in the industry of red clay-based ceramic tiles, since the results found both in laboratory and in the industry have shown that the test samples produced from the formulations with up to 4% feldspar and those produced with up to 8% feldspar and residue permitted a reduction in the water absorption rate and an increase in the mechanical resistance while those samples produced with up to 4% residue had an increase in the mechanical resistance when compared to those produced from the basic mass and that the formulation with 2% feldspar and residue presented the best technological properties, lowering the sintering temperature down to 1120°C