Computer aided design of horizontal axis turbine

This paper presents a computer-based method for modelling the blades of horizontal axis turbines using B-spline surfaces. The method uses common design parameters for the geometry of this type of turbine and produces a final set of B-spline surfaces for the geometry of the blades that can be used for the visualisation, calculations and construction of the rotor surface. The method begins with the creation of a 3D set of offsets that constitute the rotor blades based on a 2D definition of the airfoils, which is normally used in the design of different stations along the rotor blade. It also uses geometrical parameters such as the skew and rake or coning distribution. The method stresses the fitting of the blade?s leading edge, which has a significant impact on the properties of the rotor and separately models the trailing edge of the blades. B-spline curves and surfaces are used in this method because they are widely used in CAD-CAM software products and can be easily exported to other programs

Texture Evolution of AZ31 Magnesium Alloy Sheet at High Strain Rates

In the current contribution the mechanical behaviour at high strain rates of AZ31 magnesium alloy sheet is studied. Uniaxial deformation properties were studied by means of tensile split Hopkinson pressure bar (SHPB) at different temperatures. The influence of the strain rate and temperature on the deformation mechanisms was investigated by means of electron backscatter diffraction (EBSD) and neutron diffraction. It is shown that twinning plays an important role on high strain rate deformation of this alloy, even at elevated temperatures. Significant evidence of prismatic slip as a deformation mechanism is observed, also at warm temperatures, leading to the alignment of directions with the tensile axis and to a spread of the intensities of the basal pole figure towards the in-plane direction perpendicular to the tensile axis. The rate of decrease of the CRSS of non-basal systems is observed to be slower than at quasi-static rates. Secondary twinning and pyramidal slip were also outlined for some conditions. At warm temperatures, in contrast to quasi-static range, a generalized dynamic recrystallization is not observed. Moreover, the activation of rotational recrystallization mechanisms is reporte

Twinning and grain subdivision during dynamic deformation of a Mg AZ31 sheet alloy at room temperature

The microstructural evolution of an AZ31 rolled sheet during dynamic deformation at strain rates of ∼103 s−1 has been investigated by electron backscatter diffraction, X-ray and neutron diffraction. The influence of orientation on the predominant deformation mechanisms and on the recovery processes taking place during deformation has been systematically examined. The results have been compared with those corresponding to the same alloy tested quasi-statically under equivalent conditions. It has been found that strain rate enhances the activation of extension twinning dramatically, while contraction and secondary twinning are not significantly influenced. The polarity of extension twinning is even reversed in some grains under selected testing conditions. Significant grain subdivision by the formation of geometrically necessary boundaries (GNBs) takes place during both quasi-static and dynamic deformation of this AZ31 alloy. It is remarkable that GNBs of high misorientations form even at the highest strain rates. The phenomenon of recovery has been found to be orientation dependen

La hegemonía cultural del glolugar: entre la relegación y la reivindicación local. El caso de Valencia

El artículo tiene por objeto abordar cómo la hegemonía del glolugar, en tanto que figura paradigmática de los procesos urbanos neoliberales, ha implicado un determinado modelo de política cultural y de desarrollo urbano que hemos podido singularizar en el caso de la ciudad de Valencia y la Ciudad de las Artes y de las Ciencias. La hegemonía cultural del glolugar no se puede entender sin enmarcarla en una tendencia global como es la extensión del urbanismo neoliberal, la ciudad es concebida como una entidad competitiva inmersa en un espacio global que promueve el mercado y la mentalidad emprendedora a través de nuevas prácticas de la gestión pública. En el caso de Valencia, el proyecto de ciudad neoliberal ha pivotado sobre los grandes proyectos y eventos, con la espectacular Ciudad de las Artes y de las Ciencias como mascarón de proa. Nuestra reflexión pretende vincular urbanismo neoliberal, política cultural y modelo de ciudad, utilizando como clave de bóveda el rol que el glolugar en nuestro caso la Ciudad de las Artes y de las Ciencias, tiene en el proceso. Sin embargo, frente a las políticas neoliberales del glolugar se ha ido conformando desde los barrios populares una serie de acciones socio-culturales desarrolladas por una red de asociaciones, grupos, colectivos e iniciativas culturales. Estas respuestas, unas más profesionales y otras más críticas con dicho modelo, ahora en crisis, proponen iniciativas culturales resistentes y alternativas

The cultural hegemony of the global places: between relegation and the local claim. The case of Valencia

El artículo que presentamos tiene por objeto abordar cómo la hegemonía del glolugar, en tanto que figura paradigmática de los procesos urbanos neoliberales, ha implicado un determinado modelo de política cultural que hemos podido singularizar en el caso de la ciudad de Valencia y la Ciudad de las Artes y de las Ciencias. La hegemonía cultural del glolugar no se puede entender sin enmarcarla en una tendencia global como es la extensión del urbanismo neoliberal, la ciudad es concebida como una entidad competitiva inmersa en un espacio global que promueve el mercado y la mentalidad emprendedora a través de nuevas prácticas de la gestión pública. En el caso de Valencia, el proyecto de ciudad neoliberal ha pivotado sobre los grandes proyectos y eventos, con la espectacular Ciudad de las Artes y de las Ciencias como mascarón de proa. Nuestra reflexión pretende vincular urbanismo neoliberal, política cultural y modelo de ciudad, utilizando como clave de bóveda el rol que el glolugar en nuestro caso la Ciudad de las Artes y de las Ciencias, tiene en el proceso. Sin embargo, frente a las políticas neoliberales del glolugar se ha ido conformando desde los barrios populares una serie de acciones socio-culturales desarrolladas por una red de asociaciones, grupos, colectivos e iniciativas culturales, que abordamos en cuarto lugar. Estas respuestas, unas más profesionales y otras más críticas con dicho modelo, ahora en crisis, proponen iniciativas culturales resistentes y alternativas.This paper discusses how the hegemony of the global place (glolugar), the paradigmatic figure of the urban neoliberal processes, has implied a certain model of cultural policy and urban development. This model has been developed in the project of City of the Arts and of the Sciences, in Valencia City. The cultural hegemony of the glolugar cannot be understood without framing it in a global trend since it is the extension of the neoliberal urbanism. In this frame, the city is conceived as a competitive entity in a global space that promotes the commoditization of urban space and the entrepreneurial attitude in the local public management. From the analysis of the City of the Arts and of the Sciences, we will investigate the links between neoliberal urbanism, cultural politics and city model. Nevertheless, we will show how the struggles against these neoliberal policies of the glolugar there has been conforming in the popular neighborhoods some socio-cultural actions, to counteract this gentrifying trend and to propose an alternative culture and urban planning

La Restauració d'instruments de física de la Universitat de Barcelona

According to our archives, in the later years of the 19th century it is on record that classes of Physics, Astronomy and Experimental Physics among others were taking place in the University of Barcelona. For this reason, at that time the University acquired the first instruments for the teaching of Physics which increased notably in number until the end of the century and have continued to do so since then. The Faculty of Physics of the University of Barcelona has collected along his years of existence an important collection of scientific instruments, related both for research and for teaching. A small part has been restored but there is still a lot of work to do

DO SPORT COMPRESSION STOCKINGS IMPROVE COMFORT AND ACCELEROMETRY PARAMETERS IN RUNNERS?

In this study, we analysed accelerometry data from runners foot strikes with and without sport compression stockings. Also, we measured comfort perceived with these garments due its importance to a succesful performance. Ten male runners (n=10) exerted two laboratory test condition in different days: a) without compression stockings and b) with one kind of compression in each leg. Accelerometry data were registered using sensors in tibia and head. Also participants filled out a comfort test in stockings’ condition. Medium compression (MC) impacts attenuation was lower than no compression (NC) condition (p\u3c0,05). General comfort perceived was 66%. In conclusion, compression stockings demonstrated a protective effect against impacts and were perceived as comfortable

Influence of hesperidin on the systemic and intestinal rat immune response

Polyphenols, widely found in edible plants, influence the immune system. Nevertheless, the immunomodulatory properties of hesperidin, the predominant flavanone in oranges, have not been deeply studied. To establish the effect of hesperidin on in vivo immune response, two different conditions of immune system stimulations in Lewis rats were applied. In the first experimental design, rats were intraperitoneally immunized with ovalbumin (OVA) plus Bordetella pertussis toxin and alum as the adjuvants, and orally given 100 or 200 mg/kg hesperidin. In the second experimental design, rats were orally sensitized with OVA together with cholera toxin and fed a diet containing 0.5% hesperidin. In the first approach, hesperidin administration changed mesenteric lymph node lymphocyte (MLNL) composition, increasing the TCRαβ+ cell percentage and decreasing that of B lymphocytes. Furthermore, hesperidin enhanced the interferon (IFN)-γ production in stimulated MLNL. In the second approach, hesperidin intake modified the lymphocyte composition in the intestinal epithelium (TCRγδ+ cells) and the lamina propria (TCRγδ+, CD45RA+, natural killer, natural killer T, TCRαβ+CD4+, and TCRαβ+CD8+ cells). Nevertheless, hesperidin did not modify the level of serum anti-OVA antibodies in either study. In conclusion, hesperidin does possess immunoregulatory properties in the intestinal immune response, but this effect is not able to influence the synthesis of specific antibodies