Papers by JOAQUIN BASTIDA
Scientific Reports
This study analyses the interactions among crustose and lichenicolous lichens growing on gypsum b... more This study analyses the interactions among crustose and lichenicolous lichens growing on gypsum biocrusts. The selected community was composed of Acarospora nodulosa, Acarospora placodiiformis, Diploschistes diacapsis, Rhizocarpon malenconianum and Diplotomma rivas-martinezii. These species represent an optimal system for investigating the strategies used to share phycobionts because Acarospora spp. are parasites of D. diacapsis during their first growth stages, while in mature stages, they can develop independently. R. malenconianum is an obligate lichenicolous lichen on D. diacapsis, and D. rivas-martinezii occurs physically close to D. diacapsis. Microalgal diversity was studied by Sanger sequencing and 454-pyrosequencing of the nrITS region, and the microalgae were characterized ultrastructurally. Mycobionts were studied by performing phylogenetic analyses. Mineralogical and macro- and micro-element patterns were analysed to evaluate their influence on the microalgal pool availa...
Clay Minerals
ABSTRACTCompositional and microstructural analysis of mullites in porcelain whitewares obtained b... more ABSTRACTCompositional and microstructural analysis of mullites in porcelain whitewares obtained by the firing of two blends of identical triaxial composition using a kaolin B consisting of ‘higher-crystallinity’ kaolinite or a finer halloysitic kaolin M of lower crystal order was performed. No significant changes in the average Al2O3 contents (near the stoichiometric composition 3:2) of the mullites were observed. Fast and slow firing at the same temperature using B or M kaolin yielded different mullite contents. The Warren–Averbach method showed increase of the D110 mullite crystallite size and crystallite size distributions with small shifts to greater values with increasing firing temperature for the same type of firing (slow or fast) using the same kaolin, as well as significant differences between fast and slow firing of the same blend at different temperatures for each kaolin. The higher maximum frequency distribution of crystallite size observed at the same firing temperature...
Presencia de pirofilita en reemplazamientos de conchas de espiriféridos (Brachiopoda) del Devónic... more Presencia de pirofilita en reemplazamientos de conchas de espiriféridos (Brachiopoda) del Devónico de la zona centroibérica. (Macizo Hespérico, España) Appearance of pyrophyllite as replacements of spiriferids (Brachiopoda) Shells of the devonian in the Central-Iberian zone (Hesperic Massif, Spain).
Journal of the European Ceramic Society, 1997
The microstructural evolution of mullite during the thermal transformation of kyanite has been st... more The microstructural evolution of mullite during the thermal transformation of kyanite has been studied in the temperature range 1200–1600 °C. The shape and size of the grains were analysed by means of SEM-EDS while crystallite size evolution was studied by X-ray line profile analyses.The results obtained showed that total transformation of kyanite to mullite takes place between 1350 and 1400
Prague, September 2-5, 2004, 2000
El Keuper de Valencia presenta dos series evaporíticas, una inferior (unidad Kl) y otra superior ... more El Keuper de Valencia presenta dos series evaporíticas, una inferior (unidad Kl) y otra superior (unidades K4 y K3). Se analizan lutitas de varias columnas y localidades en puntos centrales y marginales de la cuenca valenciana. En conexión con la sucesión de la serie detrítica intermedia a la evaporítica superior, se reconoce un cambio en la asociación de los minerales de la arcilla (principalmente> desarrollo de interestratificados de clorita-esmectita), que se interpreta como resultante del confinamiento progresivo, hecho que asimismo se reflej a en el contenido en boro de las arcillas.
Microstructural information on the physical properties of nanocrystalline materials have imporlan... more Microstructural information on the physical properties of nanocrystalline materials have imporlanles technological applications. The applied mineralogy of great importance in the ceramic industry, aims to phase characterization minerals with nanometric dimensions: of great importance in the physical properties of the porcelain. Many microstructure properties (crystallite size and shape, lattice distortion, ...) can be characterized by crystallographic techniques polycrystalline diffraction materiais. Broadening analysis diffraction peaks allows characterization of domains diffraction (usually called crystallites). In this paper we present the analysis microestrutural (crystallite size and lattice distortion) X-ray diffraction of ias majority phases (corundum, quartz and mullite) present in a siliceous and aluminous porcelain electrotechnical applications obtained by cooking at about 1300 ºC.
RESUMEN Se analizan las características fisicoquímicas, mineralógicas y tecnológicas de arcillas ... more RESUMEN Se analizan las características fisicoquímicas, mineralógicas y tecnológicas de arcillas pertenecientes a diversas formaciones geológicas aflorantes en la provincia de Valencia, utilizadas o utilizables como materias primas cerámicas. Ceramic clays of the province of Valencia An analysis is made of the physical, chemical, mineralogical and technological characteristics of clays belonging to several geological formations that appear on the surface in the province of Valencia, which are used or may be used as ceramic raw materials. Argües céramiques de la province de Valence L'analyse porte sur les caractéristiques physico-chimiques, minéralogiques et techniques d'argiles qui appartiennent'a diverses formations géologiques affleurant dans la province de Valence et qui sont utilisées ou utilisables comme matières premieres cáramiques. Keramische Tone in der Provinz Valencia Es werden die physikalisch-chemischen, mineralogischen und technologischen Eigenschaften von ...
See articles in "Cryst. Res. Technol. 31 (1996) 1085-1093" and "Journal of the Eur... more See articles in "Cryst. Res. Technol. 31 (1996) 1085-1093" and "Journal of the European Ceramic Society 20 (2000) 403-412"
The coals of the district of Teruel (NE Spain) presents as mine wastes several industrial mineral... more The coals of the district of Teruel (NE Spain) presents as mine wastes several industrial minerals aud rocks (sands, kaolins, clays, Al-sulfates) the mining of wich would be interesting. The aim of this work is the mineralogical an ceramic characterisation of these cLays. So mineralogical and petrographical data as well as íechnological data concerning granulometry, chemical analysis and Atterberg index have bean used in order to compare these clays with those analized and typified in previous works and with those actually used as ceramic raw materials in the NP of Teruel.
See article in "Bol.Soc.Esp. Mineralogía 19 (1996) 119-129"
En el presente trabajo se estudia la reducción de la porosidad superficial de cuerpos cerámicos p... more En el presente trabajo se estudia la reducción de la porosidad superficial de cuerpos cerámicos porosos por láser. El tratamiento se realiza en dos etapas: En la primera las superficies de los cuerpos cerámicos se impregnan con una solución basada en silicato sódico y/o potásico susceptible de formar vidrio durante el tratamiento láser. En la segunda etapa se irradian los cuerpos cerámicos, ensayándose diferentes configuraciones de los parámetros de la radiación láser. Se realizan ensayos de absorción de agua para evaluar la evolución de la porosidad, obteniendo reducciones significativas con respecto al valor de la cerámica sinterizada sin tratar. Se caracterizan las fases cristalinas en función del tipo de tratamiento por medio de difracción de rayos X, y se estudia la superficie generada mediante microscopía óptica y electrónica.
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Papers by JOAQUIN BASTIDA