Catalytic Membrane Reactor: Multilayer membranes elaboration

International audienceMethane conversion to syngas is very attractive for hydrogen or clean fuel production and provides an alternative to oil products. An efficient architecture for the membrane reactor is constituted of a porous support, a thin dense membrane and a catalyst layer. This work is focused on the elaboration process of such asymmetric membranes by co-sintering of at least the porous support and the dense membrane and specially the choice of well adapted materials. La0.8Sr0.2Fe0.7Ga0.3O3-δ perovskite material has been chosen as the dense membrane because it exhibits a good compromise between oxygen flux and stability. The choice of the material for the porous support is mainly oriented by the sintering behaviour of the membrane, the thermal expansion behaviour of both layers to avoid cracks formation under working conditions and the chemical inertness of both materials. Several formulations fulfilling these three requirements were synthesized by liquid phase reaction and tape-cast. A pore forming agent was added in the support tapecasting slurry in order to create a controlled porosity. Then, the porous support has been characterized in term of gas permeability and thermal expansion under working conditions. Keywords: Ceramic membrane, co-sintering, perovskite, syngas, mixed conducting materials

Oxygen permeation and dimensional stability under pO2 gradient of (La,Sr)(Fe, Ga)O3-delta perovskite membranes

International audienceNatural gas conversion into syngas, is very attractive for hydrogen or cleanfuel production and provides a new alternative to oil products ......

Catálogo provisional de hongos hipogeos de Asturias y posibles fitobiontes asociados

Censo provisional de hongos con ciclo vital hipogeo hallados en la Comunidad Autónoma del Principado de Asturias y relación de posibles fitobiontes a ellos asociados. Se describen recolecciones de algunos infrecuentes táxones hallados en la zona: Arcangeliella stephensii, Elaphomyces aculeatus, E. cyanosporus. E. decipiens, E. leucosporus, E. mutabilis, E. papillatus, E. persoo nii y E. septatus, Genabea fragi lis, Genea vagans, G/01l1US flavisporum. Gymnomyces xanthosporus, Hysterangium calcareum, H. pompholyx, Stephensia bombycina , S. crocea, Tuber excavatum f. ntonticellianum, T foetidum, T fulgens , T mesentericum y T regianum. Un total de 85 táxones han sido censados para el área de estudio.This is a provisional ccnsus of hypogeous fungi from the Autonomous Community of the "Principado de Asturias", and it reports their possible hosts. Collections of sorne infrequent taxa found in the area are included, i.e, Arcange/iella ste phensii, Elaphomy ces aculeatus, E. cyanosporus, E. decipiens, E. leucosporus , E. muta bilis, E. papillatus. E. persoonii and E. septatus, Genabea fragilis, Genea vagans, G/O/llUS flavisporum, Gymnomyces xanthosporus , Hysterangium calcareum, H. pompholyx, Stephensia bombycina, S. crocea, Tuber excavatum f. monticellianum, T foetidum, T fulgens, mesentericum and T regianum. . A total of 85 taxa are recorded

Catálogo provisional de hongos hipogeos de Asturias y posibles fitobiontes asociados

Censo provisional de hongos con ciclo vital hipogeo hallados en la Comunidad Autónoma del principado de Asturias y relación de posibles fitobiontes a ellos asociados. Se describen recolecciones de algunos infrecuentes táxones hallados en la zona: Arcangeliella stephensii, Elaphomyces aculeatus, E. cyanosporus. E. decipiens, E. leucosporus, E. mutabilis, E. papillatus, E. persoo nii y E. septatus, Genabea fragilis, Genea vagans, Glomus flavisporum. Gymnomyces xanthosporus, Hysterangium calcareum, H. pompholyx, Stephensia bombycina, S. crocea, Tuber excavatum f. ntonticellianum, T foetidum, T fulgens, T mesentericum y T regianum. Un total de 85 táxones han sido censados para el área de estudio.This is a provisional census of hypogeous fungi from the Autonomous Community of the "Principado de Asturias", and it reports their possible hosts. Collections of sorne infrequent taxa found in the area are included, i.e, Arcangeliella stephensii, Elaphomyces aculeatus, E. anosporus, E. decipiens, E. leucosporus, E. muta bilis, E. papillatus. E. persoonii and E. septatus, Genabea fragilis, Genea vagans, Glomus flavisporum, Gymnomyces xanthosporus, Hysterangium calcareum, H. pompholyx, Stephensia bombycina, S. crocea, Tuber excavatum f. monticellianum, T foetidum, T fulgens, mesentericum and T regianum. A total of 85 taxa are recorded

Colour segmentation of citrus fruits images for stem location

After mechanical harvesting, Cirrus fruits with long stems may cause damage on adjacent fruits during transportation and storage. A first step to solve before measuring the stem and taking the decision of cutting it or not, is the orientation of fruits. For this purpose, an image analysis method to locate the stem insertion point based on colour segmentation is proposed and evaluated. Four classes were defined for segmentation: background, peel, stem-calyx and cut stem, and a classifier based on bayesian decision rules was developed assuming that the independent variables (RGB) followed a normal distribution function, and that the classes had equal covariance matrix. The results point out an excellent performance of the classifier for the first two classes, and satisfactory for the other two. The location algorithm used information of areas and centroids to estimate the coordinates of the stem insertion point. From a total of 86 images tested, it was correctly estimated a 90,3% of times. The method resulted to be efficient for fruits without leaves appended to the stem

Oxygen permeation, thermal and chemical expansion of (La, Sr)(Fe, Ga)O3−δ perovskite membranes

International audienceDense ceramic membranes made from mixed conductors are interesting because of their potential applications formethane conversion into syngas (H2 and CO mixture). Such membranes need to present a low differential dimensional variation between the opposite faces submitted to a large gradient of oxygen partial pressure, in order to minimize mechanical stresses generated through the membrane thickness. Besides, high oxygen permeability is required for high methane reforming rate. La(1−x)SrxFe(1−y)GayO3−δ materials fulfil these two main requirements and were retained as membranes in catalytic membrane reactors (CMR). The variations of expansion and oxygen permeation of La(1−x)SrxFe(1−y)GayO3−δ perovskite materials with the partial substitution of lanthanum and iron cations, temperature and oxygen partial pressure, were studied. For low temperatures (800 ◦C), TEC, then dimensional stability of the membrane, and oxygen permeation of La(1−x)SrxFe(1−y)GayO3−δ materials, are significantly affected by Sr content and oxygen partial pressure. Ga has a stabilisation effect on the TEC and has no influence on oxygen permeation flux. A good compromise between dimensional stability and oxygen permeation of materials was found to be La0.7Sr0.3Fe0.7Ga0.3O3−δ compositio

Evaluación no destructiva de la calidad de productos hortofrutícolas en líneas de confección

En el sector hortofrutícola, la exigencia de calidad por parte del consumidor es cada vez mayor. Actualmente, hay una creciente demanda dirigida a una adecuada automatización de los procesos industriales que permitan garantizar una calidad excelente del producto final. El Centro de AgroIngeniería del Instituto Valenciano de Investigaciones Agrarias (IVIA), en colaboración con el sector industrial, ha desarrollado durante los últimos años sensores electrónicos y sistemas de inspección por visión artificial que permiten una clasificación automática de distintos productos hortofrutícolas muy significativos para la agricultura española, entre los que cabe citar: - Un sensor de firmeza capaz de clasificar melocotones en tres categorías: muy firmes, firmes y poco firmes. Los ensayos realizados en una línea de confección precomercial demuestran que el sensor puede trabajar adecuadamente a 8 frutas s-1 y es capaz de clasificar la firmeza con un 80% de repetibilidad. - Un prototipo capaz de inspeccionar automáticamente granos de granada para el consumo por visión artificial. La máquina individualiza, inspecciona, clasifica y separa los granos de granada en cuatro de categorías de calidad que son función de su color y tamaño, rechazando aquellos que no cumplen las especificaciones mínimas y agrupando los que presentan características similares. Con ello se consigue el envasado en lotes de producto uniforme y de alta calidad, resultando más atractivo al consumidor. - Un sistema para clasificar automáticamente gajos de mandarina para conserva por visión artificial. El sistema distingue entre gajos enteros, rotos o dobles, además de detectar la presencia de semillas en los gajos. El sistema clasifica correctamente más del 75% de los gajos analizados

Análisis del orden de entrada en el sistema de franquicia español

Desde las perspectivas de marketing, dirección estratégica y organización industrial se ha analizado la sostenibilidad de las ventajas competitivas (Barney, 1991; Hamel y Prahalad, 1994; Carpenter y Nakamoto, 1994; Kalyanaram et al., 1995; Covin et al., 1999). Así, la teoría del orden de entrada explica que aquellas empresas que entran antes en un mercado obtienen ventajas frente a las siguientes entrantes (Michael, 2003). Por tanto, esta investigación, centrada en el sector de la franquicia, analiza la influencia del momento de entrada en los resultados empresariales.From marketing, strategic management and industrial organization perspectives, it has been analyzed the sustainability of competitive advantages (Barney, 1991; Hamel and Prahalad, 1994; Carpenter and Nakamoto, 1994; Kalyanaram et al., 1995; Covin et al., 1999). The first-mover advantage explains that those firms that entry before in the market gain more advantages than the followers (Michael, 2003). Therefore, this research, focused on the franchised distribution system, analyzes the influence of the timing of entry on profitability