Optimización de un dispositivo de bombeo asimétrico

El bombeo asimétrico se caracteriza por ser una técnica de bombeo sin válvulas en el que la presión ejercida por el actuador se localiza en la mitad del elemento activo, siendo la instalación asimétrica respecto de dicho elemento ya que si fuera completamente simétrico no habría generación de flujo. Una posible aplicación del bombeo asimétrico es la implementación de implantes activos cardiovasculares para personas que padecen el Síndrome del Corazón Izquierdo Hipoplásico y necesitan someterse al procedimiento de Fontan. El objetivo va a ser optimizar el dispositivo de bombeo asimétrico variando los diferentes parámetros de la instalación y conseguir así las mejores prestaciones posibles. También se describirá la instalación con su correspondiente modelo en 3D y se explicará cómo se ha elaborado el actuador que comprime el tubo flexible.Asymmetrical pumping is characterized by being a valveless pumping technique in which the pressure exerted by the actuator is in the middle of the active element, the installation being asymmetric with respect to said element, since if it were full symmetric there would be no flow generation. The most promising application of asymmetric pumping is the realization of cardiovascular implants for people who suffer Hypoplastic Left Heart Syndrome and need to undergo the Fontan procedure. The objective will be to optimize the asymmetric pumping device by varying the different parameters of the installation and achieve the best possible performance. The installation will also be described with its corresponding 3D model, and it will be explained how the actuator that compresses the flexible tube has been made.Departamento de Ingeniería Energética y FluidomecánicaGrado en Ingeniería en Tecnologías Industriale

Influence of the sputtering flow regime on the structural properties and magnetic behavior of Fe-Ga thin films (Ga ∼ 30 at.%)

In this paper we analyze the structure of Fe-Ga layers with a Ga content of ∼30 at.% deposited by the sputtering technique under two different regimes. We also studied the correlation between the structure and magnetic behavior of the samples. Keeping the Ar pressure fixed, we modified the flow regime from ballistic to diffusive by increasing the distance between the target and the substrate. X-ray diffraction measurements have shown a lower structural quality when growing in the diffusive flow. We investigated the impact of the growth regime by means of x-ray absorption fine structure (XAFS) measurements and obtained signs of its influence on the local atomic order. Full multiple scattering and finite difference calculations based on XAFS measurements point to a more relevant presence of a disordered A2 phase and of orthorhombic Ga clusters on the Fe-Ga alloy deposited under a diffusive regime; however, in the ballistic sample, a higher presence of D0_3/B2 phases is evidenced. Structural characteristics, from local to long range, seem to determine the magnetic behavior of the layers. Whereas a clear in-plane magnetic anisotropy is observed in the film deposited under ballistic flow, the diffusive sample is magnetically isotropic. Therefore, our experimental results provide evidence of a correlation between flow regime and structural properties and its impact on the magnetic behavior of a rather unexplored compositional region of Fe-Ga compounds

Local and medium range order influence on the magnetic behavior of sputtered ga-rich fega thin films

We have investigated the influence of the growth power on the structural properties of Fe_100_(-x)Ga_x (x ca. 29) films sputtered in the ballistic regime in the oblique incidence. By means of different structural characterizations, mainly X-ray diffraction and X-ray absorption spectroscopy, we have reached a deeper understanding about the influence of the local and medium range order on the magnetic behavior of Ga-rich FeGa thin films. On the one hand, the increase of the growth power reduces the crystallite size (medium order) that promotes the decrease of the coercive field of the layers. On the other hand, the growth power also determines the local order as it controls the formation of the A2, B2, and D0_3 structural phases. The increase of the uniaxial in-plane magnetic anisotropy with growth power has been correlated with the enhancement of both Ga pairs and a tetragonal distortion. The results presented in this work give more evidence about the magnetic anisotropy sources in Ga-rich FeGa alloys, and therefore, it helps to understand how to achieve a better control of the magnetic properties in this family of alloys

Real-time evolution of a large-scale relativistic jet

Context. Astrophysical jets are ubiquitous in the Universe on all scales, but their large-scale dynamics and evolution in time are hard to observe since they usually develop at a very slow pace. Aims. We aim to obtain the first observational proof of the expected large-scale evolution and interaction with the environment in an astrophysical jet. Only jets from microquasars offer a chance to witness the real-time, full-jet evolution within a human lifetime, since they combine a 'short', few parsec length with relativistic velocities. Methods. The methodology of this work is based on a systematic recalibraton of interferometric radio observations of microquasars available in public archives. In particular, radio observations of the microquasar GRS 1758-258 over less than two decades have provided the most striking results. Results. Significant morphological variations in the extended jet structure of GRS 1758-258 are reported here that were previously missed. Its northern radio lobe underwent a major morphological variation that rendered the hotspot undetectable in 2001 and reappeared again in the following years. The reported changes confirm the Galactic nature of the source. We tentatively interpret them in terms of the growth of instabilities in the jet flow. There is also evidence of surrounding cocoon. These results can provide a testbed for models accounting for the evolution of jets and their interaction with the environment.Comment: 5 pages, 3 figures, 2 tables. Accepted for publication in Astronomy and Astrophysics Letter

IMEGE: Image-based Mathematical Expression Global Error

Mathematical expression recognition is an active research eld that is related to document image analysis and typesetting. Several approaches have been proposed to tackle this problem, and automatic methods for performance evaluation are required. Mathematical expressions are usually represented as a coded string like LATEX or MathML for evaluation purpose. This representation has ambiguity problems given that the same expression can be coded in several ways. For that reason, the proposed approaches in the past either manually analyzed recognition results or they reported partial errors as symbol error rate. In this study, we present a novel global performance evaluation measure for mathematical expression based on image matching. In this way, using an image representation solves the representation ambiguity as well as human beings do. The proposed evaluation method is a global error measure that also provides local information about the recognition result.Álvaro Muñoz, F.; Sánchez Peiró, JA.; Benedí Ruiz, JM. (2011). IMEGE: Image-based Mathematical Expression Global Error. http://hdl.handle.net/10251/1308

An integrated grammar-based approach for mathematical expression recognition

This is the author’s version of a work that was accepted for publication in Pattern Recognition. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Pattern Recognition 51 (2016) 135–147. DOI 10.1016/j.patcog.2015.09.013.Automatic recognition of mathematical expressions is a challenging pattern recognition problem since there are many ambiguities at different levels. On the one hand, the recognition of the symbols of the mathematical expression. On the other hand, the detection of the two-dimensional structure that relates the symbols and represents the math expression. These problems are closely related since symbol recognition is influenced by the structure of the expression, while the structure strongly depends on the symbols that are recognized. For these reasons, we present an integrated approach that combines several stochastic sources of information and is able to globally determine the most likely expression. This way, symbol segmentation, symbol recognition and structural analysis are simultaneously optimized. In this paper we define the statistical framework of a model based on two-dimensional grammars and its associated parsing algorithm. Since the search space is too large, restrictions are introduced for making the search feasible. We have developed a system that implements this approach and we report results on the large public dataset of the CROHME international competition. This approach significantly outperforms other proposals and was awarded best system using only the training dataset of the competition. (C) 2015 Elsevier Ltd. All rights reserved.This work was partially supported by the Spanish MINECO under the STraDA research project (TIN2012-37475-C02-01) and the FPU Grant (AP2009-4363).Álvaro Muñoz, F.; Sánchez Peiró, JA.; Benedí Ruiz, JM. (2016). An integrated grammar-based approach for mathematical expression recognition. Pattern Recognition. 51:135-147. https://doi.org/10.1016/j.patcog.2015.09.013S1351475

Ergogenic aids in competitive handball players: a narrative review.

Handball performance is a team-sport characterized by high intensity efforts interspersed with recovery periods. Due to high demands of handball performance, the use of ergogenic aids is a common strategy of handball players with the aim of enhancing handball performance, to allow more effective training, and to increase the rate of recovery. Although the use of ergogenic aids is generalized in the whole spectrum of competitive handball (e.g., from recreational to professional players), only a few ergogenic aids have been investigated to test their effectiveness to increase handball performance. In addition, no previous study has summarized the scientific literature on this topic to determine the ergogenic aids with good level of evidence regarding their effectiveness to increase handball physical performance. Thus, the aim of this narrative review was to describe the prevalence in the use of ergogenic aids in handball players and to analyse this information to identify which of these substances may increase physical performance in an intermittent sport such as competitive handball.post-print690 K

El proceso de implantación del Sistema de Gestión Ambiental en la Universidad Politécnica de Valencia

En este artículo se describe el proceso de implantación de un sistema de gestión ambiental, según los requisitos de la norma UNE-EN ISO 14001 y el Reglamento Europeo EMAS, en la Universidad Politécnica de Valencia. El docuento describe las 15 fases en las que se dividió el proceso de implantación y aporta indicaciones sobre las herramientas de difusión utilizadas para fomentar el conocimiento del sistema y de los impactos ambientales generados por la actividad de la universidad.Sansano Del Castillo, I.; Muñoz Sánchez, Á. (2009). El proceso de implantación del Sistema de Gestión Ambiental en la Universidad Politécnica de Valencia. http://hdl.handle.net/10251/6381

The role of surface to bulk ratio on the development of magnetic anisotropy in high Ga content Fe100-xGax thin films

In this work we show the development of bulk in-plane magnetic anisotropy in high Ga-content (Ga = 28 at. %) Fe_(100-x)Ga_x thin films as the layer thickness increases. This result is in clear contrast with the generally reported decrease of this anisotropy with the film thickness. We propose the interrelation between the enhancement of the Ga-pair correlations and a collinear distortion of the bcc structure within the sample plane as the origin of the magnetic anisotropy. Our results have been obtained by employing a combination of long and local range structural probe techniques with bulk and surface magnetic characterization techniques. The key point shown in this work is that the in-plane structural anisotropy and hence, the magnetic anisotropy, are developed as the layer thickness increases. This fact strongly suggests that the surface to bulk free energy ratio plays a key role in the formation of ordered phases with a distorted bcc cell in Fe_(100-x)Ga_x films with x around 28 at. %. Our work also shows the arising of new phenomena in these high Ga content alloys due to the close correlation between structural and magnetic properties

Análisis de sistemas de producción agrícola en tres municipios del departamento de Nueva Segovia, 2017-2018

En Nicaragua la agricultura, ganadería y especies forestales son la base de la economía nacional esto permite la seguridad alimentaria de las familias productoras. El presente trabajo fue realizado para caracterizar las Unidades de Producción en tres municipios del departamento de Nueva Segovia durante el período 2017-2018. Se aplicaron encuestas socieconómicas desarrolladas por la Asociación de la Central de Cooperativas (PRODECOP R, L), Community Agroecoly Network (CAN), Santa Clara University (SCU), Fundación AGROPOLIS y La Universidad Nacional Agraria, en el marco del proyecto “Evaluación de estrategias de diversificación en sistemas cafetaleros manejados por pequeños productores a pequeña escala en Mesoamérica”. Basado en la información recopilada se procedió a muestrear, procesar y analizar registros de 70 unidades productivas , a través de análisis descriptivos y multivariados. Los resultados mostraron que la mayoría de las unidades de producción son manejadas por hombres, se encuentran agrupados en cooperativas tienen acceso a los principales servicios básicos. Los productores son propietarios de sus parcelas, utilizan materiales criollos principalmente en los cultivos anuales y estén presentes algunos frutales, café, y la ganadería es poca destinada al autoconsumo. En los municipios se consideró que existe una tendencia a la diversificación de sus áreas de producción y conservación de la cobertura forestal encontrándose 39 especies forestales agrupadas en 19 familias botánicas, las cuales son empleadas con fines industriales, maderables, leña y cercas vivas. Se encontró que existe una alta disponibilidad de agua usada principalmente para el consumo de las familias y labores domésticas la cual es catalogada con una condición de buena y muy buena calidad por parte de los pobladores