Características de los elementos resistentes tipo sandwich construidos en materiales compuestos avanzados a partir de tejidos tridimensionales

Sandwich-type structures have proved to be alternatives of great success for several fields of application, and specially in the building sector. This is due to their outstanding properties of .specific rigidity and strength against bending loads and other range of advantages like fatigue and impact resistance, attainment of flat and smooth surfaces, high electric and thermal insulation, design versatility and some others. However, traditional sandwich structures present problems like their tendency towards delamination, stress concentrations in bores or screwed Joints, and pre resistance. These problems are alleviated thanks to the use of new sandwich structures built using three dimensional structures of advanced composite materials, maintaining the present advantages for more traditional sandwich structures. At this rate, these new structures can be applied in several areas where conventional sandwich structures used to be like walls, partitions, floor and ceiling structures, domes, vaults and dwellings, but with greater success.Las estructuras tipo sándwich han demostrado ser alternativas de gran éxito para diversos campos de aplicación y, en concreto, en el sector de la construcción, listo es gracias a sus excelentes propiedades de rigidez y resistencia específica frente a cargas de flexión y otra larga lista de ventajas, a la que pertenecen, por ejemplo, su buena resistencia a fatiga, resistencia al impacto, obtención de superficies lisas y suaves, elevado aislamiento térmico y eléctrico, versatilidad de diseño y otras. Sin embargo, las estructuras sándwich, tradicionales presentan una problemática consistente en su tendencia a la delaminación, concentraciones de tensiones ¿aparecidas ante la existencia de agujeros o uniones atornilladas y resistencia al fuego. Estos problemas son pifiados gracias a la aplicación de estructuras novedosas tipo sándwich, construidas a partir de tejidos tridimensionales de materiales compuestos avanzados, manteniéndose las ventajas existentes para las estructuras sándwich tradicionales. De este modo, estas nuevas estructuras pueden ser aplicadas en diversas áreas donde se venían aplicando las estructuras sándwich convencionales, pero con mayor éxito. Como son muros, tabiques, suelos, bóvedas, cúpulas, estructuras de suelo y techo y viviendas

Patrón de depleción glucogénica y respuesta metabólica muscular a la lidia en toros bravos

Se ha investigado el metabolismo muscular y el patrón de depleción glucogénica en 12 toros bravos tras la lidia para establecer su adaptación al ejercicio y el orden de intervención de las fibras musculares. Se obtuvieron biopsias musculares tras la lidia, en el músculo glúteo medio, a una profundidad absoluta de 50 mm, para realizar análisis histoquímicos y bioquímicos. El patrón de depleción glucogénica se evaluó mediante la tinción del ácido peryódico de Schiff, las concentraciones musculares de glucógeno y lactato se cuantificaron mediante fluorimetría y se midió el pH muscular. Durante la lidia, se produjo una intervención importante de las vías glucolíticas, con formación de lactato y acidosis muscular. El patrón de depleción glucogénica mostró un orden de contracción fibrilar I→IIA→IIB. El contenido muscular total de glucógeno tras la lidia dependió fundamentalmente del porcentaje de fibras IIB con contenido elevado en glucógeno. En resumen, durante la lidia existe un metabolismo muscular anaerobio intenso, a pesar de la intervención preferencial de las fibras I y IIA, resultados que podrían haberse debido al efecto del estrés psicológico y liberación de catecolaminas. El bajo pH tras la lidia indicaría una capacidad tamponadora reducida, posiblemente debido a la escasez de precursores energéticos e incapacidad de refosforilación del ADP.Muscle metabolism and glycogen depletion pattern were investigated in 12 4-year old bulls after bullfighting in order to establish their muscular adaptation to exercise and the order of recruitment of muscle fibers. Biopsies were taken immediately after bullfighting from the gluteus medium muscle at an absolute depth of 50 mm to perform histochemistry and biochemistry. Glycogen depletion pattern was evaluated by means of periodic acid Schiff’s stain and muscle glycogen and lactate concentrations were determined fluorometrically. Muscle pH was also determined. During bullfighting, a marked intervention of the glycolytic pathways occurred, with glycogen breakdown, lactate formation and muscle acidosis. Glycogen depletion pattern showed a recruitment order of I→IIA→IIB. Total muscle glycogen content after bullfighting was mainly dependent on the percentage of type IIB fibers with high content in glycogen. In summary, the results showed the high anaerobic metabolism during bullfighting, in spite of the main intervention of type I and IIA fibers, which could have been linked to psychological stress and catecholamines release. Furthermore, the low pH could be indicative of a reduced muscle buffer capacity, possible due to the lack of energy precursors and incapacity for ADP rephosphorilationFacultad de Ciencias Veterinaria

Electron Bernstein waves emission in the TJ-II Stellarator

Taking advantage of the electron Bernstein waves heating (EBWH) system of the TJ-II stellarator, an electron Bernstein emission (EBE) diagnostic was installed. Its purpose is to investigate the B-X-O radiation properties in the zone where optimum theoretical EBW coupling is predicted. An internal movable mirror shared by both systems allows us to collect the EBE radiation along the same line of sight that is used for EBW heating. The theoretical EBE has been calculated for different orientations of the internal mirror using the TRUBA code as ray tracer. A comparison with experimental data obtained in NBI discharges is carried out. The results provide a valuable information regarding the experimental O-X mode conversion window expected in the EBW heating experiments. Furthermore, the characterization of the radiation polarization shows evidence of the underlying B-X-O conversion process.Comment: 21 pages, 14 figure

Differences in muscle enzyme profile and metabolic response to fighting in bulls from one to three years old

The metabolic response to exercise is partially linked to muscle enzyme profile, and both factors might be influenced by ageing. This research aims: 1) To analyze the differences in muscle characteristics of fighting bulls of different ages; and 2) To assess whether the muscle enzyme profile is affected by ageing in the same way it affects other bovine breeds. Muscle biopsies from gluteus medius and semitendinosus muscles were withdrawn immediately after bullfighting, at depths of 3 and 5 cm, from a total of 24 animals, belonging to three age groups: A (1-year-olds; n=6), B (2-year-olds; n=6) and C (3-year-olds; n=12). Muscle concentrations of glycogen, lactate, adenosin triphosphate and glucose-6-P were determined. In addition, activities of citrate synthase, 3-OH-acyl-dehydrogenase, glycogen phosphorylase, lactate dehydrogenase and hexokinase were measured. No significant differences were found between the two analyzed muscles and neither between depths for any of the muscle parameters. Group A showed lower muscle lactate accumulation, with positive correlations between oxidative and glycolytic enzymes, reflecting a balance between both metabolic pathways. Group B was the most oxidative, whereas group C was the most glycolytic. Therefore, muscle oxidative potential achieved its maximum at 2 years of age, whereas the glycolytic capacity increased progressively with ageing. These results are different from those showed by other bovine breeds, with a progressive reduction in oxidative potential from birth. In conclusion, age significantly influences metabolic response to fighting as well as muscle enzyme profile in bulls

Biological actions and determinant factors of the circulating concentrations of insulin-like growth factor type 1, IGF-1, in the horse

El eje somatotrópico es esencial para el desarrollo somático del organismo, determinando el metabolismo celular. Aunque está constituido por diversas hormonas, los componentes esenciales son tres: la insulina, la hormona de crecimiento o GH y los factores de crecimiento similares a la insulina, tipos 1 y 2 (IGF-1 e IGF-2). La cuantificación de la GH es complicada debido, en primer lugar, a su liberación episódica hacia la circulación sistémica y en segundo lugar, a su corta vida media en sangre, unos 20 min. Uno de los lugares de actuación de la GH es el hígado, donde induce la síntesis de IGF-1 e IGF-2. La cuantificación de estos factores, por tanto, se considera un marcador fiable de la función hipofisaria y de la actividad del eje somatotrópico. En la presente revisión bibliográfica, en primer lugar, se describen las principales acciones biológicas del IGF-1. En segundo lugar, se presentan los factores principales que afectan significativamente a sus concentraciones circulantes. Entre estos factores, destacan el tamaño corporal, raza, edad, sexo, momento de la extracción de la muestra, ritmos circadianos, dieta, privación de comida, ejercicio y entrenamiento. El efecto de estos factores debe ser conocido antes de llevar a cabo una aplicación clínica e investigadora del IGF-1 en el caballoThe somatotropic axis is pivotal for somatic development and cell metabolism. Although it is composed by several hormones, the most important components are three: insulin, growth hormone or GH and insulin-like growth factors type 1 and 2 (IGF- 1 and IGF-2). The measurement of GH is difficult and inaccurate, because two main reasons: firstly, the GH hormone is released in an episodic way and secondly, its blood half-life is short, about 20 min. The GH hormone has significant actions on the liver, inducing the synthesis of IGF-1 and IGF-2. The measurement of these factors, therefore, is considered a reliable marker of the activity of the hypophysis and the somatotropic axis. In the present review, firstly, we will describe the main biological actions of the IGF-1 and secondly, we will define the main factors that could significantly influence the circulating concentrations of IGF-1. Among these factors, the most important are body size, breed, age, gender, time of blood extraction, circadian rhythms, diet, food privation, exercise and training. The effect of these factors should be assessed prior to extended clinical and research use of IGF-1 in horse

Stellarator Optimization Using a Distributed Swarm Intelligence-Based Algorithm

The design of enhanced fusion devices constitutes a key element for the development of fusion as a commercial source of energy. Stellarator optimization presents high computational requirements because of the complexity of the numerical methods needed as well as the size of the solution space regarding all the possible configurations satisfying the characteristics of a feasible reactor. The size of the solution space does not allow to explore every single feasible configuration. Hence, a metaheuristic approach is used to achieve optimized configurations without evaluating the whole solution space. In this paper we present a distributed algorithm that mimics the foraging behaviour of bees. This behaviour has manifested its efficiency in dealing with complex problems

Improvements of the particle-in-cell code EUTERPE for petascaling machines

In the present work we report some performance measures and computational improvements recently carried out using the gyrokinetic code EUTERPE (Jost, 2000 [1] and Jost et al., 1999 [2]), which is based on the general particle-in-cell (PIC) method. The scalability of the code has been studied for up to sixty thousand processing elements and some steps towards a complete hybridization of the code were made. As a numerical example, non-linear simulations of Ion Temperature Gradient (ITG) instabilities have been carried out in screw-pinch geometry and the results are compared with earlier works. A parametric study of the influence of variables (step size of the time integrator, number of markers, grid size) on the quality of the simulation is presented.Fil: Sáez, Xavier. Barcelona Supercomputing Center - Centro Nacional de Supercomputacion; EspañaFil: Soba, Alejandro. Barcelona Supercomputing Center - Centro Nacional de Supercomputacion; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sánchez, Edilberto. No especifíca;Fil: Kleiber, Ralf. No especifíca;Fil: Castejón, Francisco. No especifíca;Fil: Cela, José M.. Barcelona Supercomputing Center - Centro Nacional de Supercomputacion; Españ

GWpilot: Enabling multi-level scheduling in distributed infrastructures with GridWay and pilot jobs

Current systems based on pilot jobs are not exploiting all the scheduling advantages that the technique offers, or they lack compatibility or adaptability. To overcome the limitations or drawbacks in existing approaches, this study presents a different general-purpose pilot system, GWpilot. This system provides individual users or institutions with a more easy-to-use, easy-toinstall, scalable, extendable, flexible and adjustable framework to efficiently run legacy applications. The framework is based on the GridWay meta-scheduler and incorporates the powerful features of this system, such as standard interfaces, fair-share policies, ranking, migration, accounting and compatibility with diverse infrastructures. GWpilot goes beyond establishing simple network overlays to overcome the waiting times in remote queues or to improve the reliability in task production. It properly tackles the characterisation problem in current infrastructures, allowing users to arbitrarily incorporate customised monitoring of resources and their running applications into the system. This functionality allows the new framework to implement innovative scheduling algorithms that accomplish the computational needs of a wide range of calculations faster and more efficiently. The system can also be easily stacked under other software layers, such as self-schedulers. The advanced techniques included by default in the framework result in significant performance improvements even when very short tasks are scheduled