2,430 research outputs found

    Thicker States

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    Aqueous suspension processing of multicomponent submicronic Y-TZP/Al2O3/SiC particles for suspension plasma spraying

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    In order to obtain thermal barrier coatings by Suspension Plasma Spraying (SPS) process with potential new self-healing ability multicomponent submicronic Y-TZP/Al2O3/SiC suspensions were prepared. For this purpose, concentrated aqueous suspensions of individual components, as well as the multicomponent mixture were studied and characterised, in terms of colloidal stability and rheological behaviour to determine the best conditions for processing and preparation of the coatings. In the study, different dispersant contents and sonication times were tested. Subsequently, low concentrated suspensions were prepared to obtain preliminary thermal barrier coatings with the optimised feedstock. Thus, ceramic coatings were deposited by SPS and then characterised in order to assess the microstructure and phase distribution, in particular, the degree of preservation of the sealing agent, SiC, in the final coating as a previous indicator of its self-healing ability

    Mecànica de fluids i termodinàmica

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    Enginyeria Tècnica en Disseny Industrial. 502: Físic

    Mineralogía de los materiales detríticos de la Fm. Escucha (Albiense inferior) en el distrito minero de Teruel (sector Suroriental de la Cordillera Ibérica)

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    The present study focuses on the determination of the source areas of the Escucha Fm. (Albian) sediments in the Teruel Mining District (NE Spain). To this en4 we have carried out a detailed study of the heavy mineral fraction of the sandstone beds from this sedimentary unit at three stratigraphic successions at the Ariño-Oliete and Utrillas subbasins. The minerals found in the stratigraphic successions studied are in low proportions and a few mineral phases are present. Quartz is the dominant phase in the light mineral association, whereas potassium feldspars and plagioclase are in trace amounts. The opaque heavy minerals are hematite and goethite with minor amounts of pyrite. Finally, the transparent heavy minerals may be divided into the three following major associations: a) turmaline, zircon and rutile (resistant minerals); b) kyanite, staurolite and almandine (metamorphic association); and c) metamorphic mineral association from the Ctrillas sub-basin, characterised by very low heavy mineral proportions, and by the absence of one or various mineral phases from the association b. The flow directions from paleochannels and the absence of metarnorphic minerals in the sandstone levels of the upper unit of the Escucha Fm at the northern areas point to the "Platuforma del Ebro" as a possihle source area The minerals with this origin, with variable morphoscopy, could proceed from sedimentary recycling The metamorphic assemblage found in the southern areas may proceed from the "Macizo Castellano", where gneiss and mica-schists are present. It is not possible to precisse exactly the age of the source areas of the detrital sediments of the Escucha Fm This is due to the fact that these may have been different through the basin evolution, and also to the evidence of recycling processes The middle and lower units of the Escucha Fm at Ariño and Oliete, where the workable coa1 seams are present, show a metamorphic assemblage which demonstrate the Paleozoic age of the source lands Consequently, the Triassic units could also supply detrital minerals to the delta system of the Escucha Fm. These results are consistent with the hypothesis of the Triassic origin of the sulphur enrichment of the coals from the Ariño-Oliete area The recycling of detrital sediments from the Escucha Fm or a different source lana could account for the proteciion of the Utrillas sub-basin against the Triassic sulphate supply, and consequently for the lower sulphur content of the coals from this area.

    νμ\nu_\mu disappearance at the SPL, T2K-I and the Neutrino Factory

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    We study the νμ\nu_\mu disappearance channel at T2K-phase I and the SPL and analyse the achievable reduction of present uncertainties in θ23\theta_{23} and Δm232\Delta m^2_{23}. We analyse the impact of discrete ambiguities in sign(Δm223\Delta m^2{23}) and sign(2tanθ232 \tan \theta_{23}). We show how the disappearance channel at the Neutrino Factory is complementary to the ``golden'' and ``silver'' appearance channels and can be used to reduce the eightfold-ambiguity problem in (θ13δ\theta_{13}-\delta).Comment: 2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascat

    Modulating the phase transition temperature of giant magnetocaloric thin films by ion irradiation

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    Magnetic refrigeration based on the magnetocaloric effect at room temperature is one of the most attractive alternative to the current gas compression/expansion method routinely employed. Nevertheless, in giant magnetocaloric materials, optimal refrigeration is restricted to the narrow temperature window of the phase transition (Tc). In this work, we present the possibility of varying this transition temperature into a same giant magnetocaloric material by ion irradiation. We demonstrate that the transition temperature of iron rhodium thin films can be tuned by the bombardment of ions of Ne 5+ with varying fluences up to 10 14 ions cm --2 , leading to optimal refrigeration over a large 270--380 K temperature window. The Tc modification is found to be due to the ion-induced disorder and to the density of new point-like defects. The variation of the phase transition temperature with the number of incident ions opens new perspectives in the conception of devices using giant magnetocaloric materials

    Mineralogía de los materiales detríticos de la Fm. Escucha (Albiense inferior) en el distrito minero de Teruel (sector Suroriental de la Cordillera Ibérica)

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    The present study focuses on the determination of the source areas of the Escucha Fm. (Albian) sediments in the Teruel Mining District (NE Spain). To this en4 we have carried out a detailed study of the heavy mineral fraction of the sandstone beds from this sedimentary unit at three stratigraphic successions at the Ariño-Oliete and Utrillas subbasins. The minerals found in the stratigraphic successions studied are in low proportions and a few mineral phases are present. Quartz is the dominant phase in the light mineral association, whereas potassium feldspars and plagioclase are in trace amounts. The opaque heavy minerals are hematite and goethite with minor amounts of pyrite. Finally, the transparent heavy minerals may be divided into the three following major associations: a) turmaline, zircon and rutile (resistant minerals); b) kyanite, staurolite and almandine (metamorphic association); and c) metamorphic mineral association from the Ctrillas sub-basin, characterised by very low heavy mineral proportions, and by the absence of one or various mineral phases from the association b. The flow directions from paleochannels and the absence of metarnorphic minerals in the sandstone levels of the upper unit of the Escucha Fm at the northern areas point to the "Platuforma del Ebro" as a possihle source area The minerals with this origin, with variable morphoscopy, could proceed from sedimentary recycling The metamorphic assemblage found in the southern areas may proceed from the "Macizo Castellano", where gneiss and mica-schists are present. It is not possible to precisse exactly the age of the source areas of the detrital sediments of the Escucha Fm This is due to the fact that these may have been different through the basin evolution, and also to the evidence of recycling processes The middle and lower units of the Escucha Fm at Ariño and Oliete, where the workable coa1 seams are present, show a metamorphic assemblage which demonstrate the Paleozoic age of the source lands Consequently, the Triassic units could also supply detrital minerals to the delta system of the Escucha Fm. These results are consistent with the hypothesis of the Triassic origin of the sulphur enrichment of the coals from the Ariño-Oliete area The recycling of detrital sediments from the Escucha Fm or a different source lana could account for the proteciion of the Utrillas sub-basin against the Triassic sulphate supply, and consequently for the lower sulphur content of the coals from this area.

    Madera en altura, estado del arte

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    This article is focused on analysing the current situation of timber high-rise construction. It begins with a historical review from the traditional Pagodas (up to 63 m tall) to visions of the future that rises to 350 m. It states the technical development that has led mass timber to today’s engineered products and its researches. It displays timber’s behaviour to fire and its properties as a structural material compared to others more commonly used in high-rise construction. It proves to be as mechanically competitive as concrete or high strength steel. Different strategies can be used against horizontal forces to obtain maximum slenderness. However, its main advantage, from an ecological point of view, is its capacity to absorb CO2, which, along its high degree of prefabrication, makes it a sustainable alternative with an increasing acceptance.El objetivo es mostrar el panorama actual de la edificación en altura con madera. Comienza con una revisión histórica desde las pagodas orientales (hasta 63m de altura) hasta las visiones de futuro (350m). Se muestra el desarrollo tecnológico que ha llevado la madera maciza hasta los productos industrializados actuales y las investigaciones en desarrollo. Se expone su comportamiento ante el fuego y las propiedades como material estructural en comparación con los materiales estructurales más utilizados para la edificación en altura: mecánicamente es tan competitivo como hormigones o aceros de alta resistencia. Ante acciones horizontales hay varias estrategias y se obtienen las esbelteces máximas alcanzables en altura. Su principal ventaja, desde el punto de vista ecológico, es su capacidad de absorber CO2, lo que, junto con el alto nivel de prefabricación, lo convierte en una alternativa sostenible cada vez con mayor aceptació

    Visceral leishmaniasis patients display altered composition and maturity of neutrophils as well as impaired neutrophil effector functions

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    Immunologically, active visceral leishmaniasis (VL) is characterised by profound immunosuppression, severe systemic inflammatory responses and an impaired capacity to control parasite replication. Neutrophils are highly versatile cells, which play a crucial role in the induction as well as the resolution of inflammation, the control of pathogen replication and the regulation of immune responses. Neutrophil functions have been investigated in human cutaneous leishmaniasis, however, their role in human visceral leishmaniasis is poorly understood. In the present study we evaluated the activation status and effector functions of neutrophils in patients with active VL and after successful anti-leishmanial treatment. Our results show that neutrophils are highly activated and have degranulated; high levels of arginase, myeloperoxidase and elastase, all contained in neutrophils’ granules, were found in the plasma of VL patients. In addition, we show that a large proportion of these cells are immature. We also analysed effector functions of neutrophils that are essential for pathogen clearance and show that neutrophils have an impaired capacity to release neutrophil extracellular traps, produce reactive oxygen species and phagocytose bacterial particles, but not Leishmania parasites. Our results suggest that impaired effector functions, increased activation and immaturity of neutrophils play a key role in the pathogenesis of VL

    Genetic selection of maternal lines and digestive efficiency in rabbits: long term selection for litter size at weaning versus hyper selection for reproductive longevity

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    The objective of the present paper is to evaluate how long-term selection for litter size at weaning or short-term hyper selection for reproductive longevity, affect the digestive utilisation of growing and lactating rabbits. A digestibility trial was carried out during the 3rd week of lactation with a total of 27 multiparous does: 14 females came from a line selected for litter size at weaning over 32 generations (V), and 13 from a recently constituted, long lived-productive line (LP). Another digestibility trial was performed during the growing period with a total of 48 growing rabbits (24 from each line). After a 7 d adaptation period, faeces were collected individually for 4 d (from 13 to 16 d of lactation or from 49 to 53 d of age, respectively). Daily feed intake and weight gain recorded during the experimental growing period were similar for both lines (137 g of dry matter (DM)/d and 48 g/d, respectively). Growing rabbits from the V-line showed greater values for the digestibility of the DM and OM (+1 percentage point; P<0.10) and signifi cantly higher values for the acid detergent fi bre (+3 percentage points; P=0.03) than animals from the LP line. No signifi cant differences for the apparent digestibility coeffi cients of crude protein, neutral detergent fi bre, crude fi bre and gross energy were observed between lines, these being on average 65.7, 23.0, 10.7 and 52.6%, respectively. Females from the LP line were initially heavier (+258 g of live weight; P=0.06), and presented a signifi cantly greater daily feed intake (+22 g DM/d; P=0.04) and milk yield (+37 g/d; P=0.01) during the pre-experimental and faeces collection phases (from 6 to 16 d of lactation). V-line lactating does displayed greater values for digestibility for all those nutrients evaluated (from +0.9 and +3.7 percentage points for the crude protein and acid detergent fi bre) compared to the LP line females, although these were only signifi cant for the DM, organic matter and gross energy (+2.3, +2.5, +2.1 percentage points; P<0.05). In conclusion, rabbits selected for litter size at weaning seem to have greater effi ciency for digestive utilisation than those hyper selected for reproductive longevity.This study has been supported by the Spanish CICYT project AGL 2004-02710/GAN.Pascual Amorós, JJ.; Ródenas, L.; Martínez, E.; Cervera, C.; Blas, E.; Baselga, M. (2008). Genetic selection of maternal lines and digestive efficiency in rabbits: long term selection for litter size at weaning versus hyper selection for reproductive longevity. World Rabbit Science. 16(3). doi:10.4995/wrs.2008.62516
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