Performance optimization in switched reluctance motor drives

In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. A prototype machine has been developed as very attractive design for a steering electric motor, both from a cost and size perspective. A fourphase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design

Modelling and Simulation of Moored Devices for Ocean Currents Energy Harnessing

The main objective of this paper is the presentation of modelling solutions off loating devices that can be used for harnessing energy from ocean currents. It has been structured into three main parts. First, the growing current interest in marine renewable energy in general, and in extracting energy from currents in particular, is presented, showing the large number of solutions that are emerging and some of the most significant types. GESMEY generator is presented in second section. It is based on a new concept that has been patented by the Universidad Politécnica de Madrid and which is currently being developed through a collaborative agreement with the SOERMAR Foundation. The main feature of this generator is that on operation is fully submerged, and no other facilities are required to move to floating state for maintenance, which greatly increases its performance. Third part of the article is devoted to present the modelling and simulation challenges that arise in the development of devices for harnessing the energy of marine currents, along with some solutions which have been adopted within the frame of the GESMEY Project, making particular emphasis on the dynamics of the generator and its contro

Dispositivo para aprovechar la energía de corrientes marinas

En este articulo se expone el proceso seguido en la definición y desarrollo de un generador, denominado GESMEY, para el aprovechamiento de la energía de las corrientes marinas situadas a más de 40 metros de profundidad, lo que junto a sus características definitorias que le permiten evolucionar en el seno marino sólo utilizando fuerzas hidrodinámicas, le definen como un dispositivo con mejores prestaciones que los existentes a la fecha. Por ello puede afirmarse que GESMEY es ya un dispositivo perteneciente a una segunda generación de convertidores

Nano-second laser interference photoembossed microstructures for enhanced cell alignment

Photoembossing is a powerful photolithographic technique to prepare surface relief structures relying on polymerization-induced diffusion in a solventless development step. Conveniently, surface patterns are formed by two or more interfering laser beams without the need for a lithographic mask. The use of nanosecond pulsed light-based interference lithography strengthens the pattern resolution through the absence of vibrational line pattern distortions. Typically, a conventional photoembossing protocol consists of an exposure step at room temperature that is followed by a thermal development step at high temperature. In this work, we explore the possibility to perform the pulsed holographic exposure directly at the development temperature. The surface relief structures generated using this modified photoembossing protocol are compared with those generated using the conventional one. Importantly, the enhancement of surface relief height has been observed by exposing the samples directly at the development temperature, reaching approximately double relief heights when compared to samples obtained using the conventional protocol. Advantageously, the light dose needed to reach the optimum height and the amount of photoinitiator can be substantially reduced in this modified protocol, demonstrating it to be a more efficient process for surface relief generation in photopolymers. Kidney epithelial cell alignment studies on substrates with relief-height optimized structures generated using the two described protocols demonstrate improved cell alignment in samples generated with exposure directly at the development temperature, highlighting the relevance of the height enhancement reached by this method. Although cell alignment is well-known to be enhanced by increasing the relief height of the polymeric grating, our work demonstrates nano-second laser interference photoembossing as a powerful tool to easily prepare polymeric gratings with tunable topography in the range of interest for fundamental cell alignment studies

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study

AbstractWe aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement >30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68–81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13–0.40; p <0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14–5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI

New Structured Materials in the Study of the Mechanobiological Processes Related to the Heart Failure

Cardiovascular diseases are the number one of death globally. According to the World Health organization 17.7 million people died from cardiovascular diseases in 2015, representing 31% of all global deaths. In these diseases the cardiac homeostasis is disrupted by a non-appropriate myocardium remodelling. The cardiac extracellular matrix (ECM) provides not only the biochemical environment but also a natural scaffold surrounding and connecting cardiac cells and distributing mechanical forces throughout the organ. Thus, the properties of the ECM are essential for the maintenance of the functional myocardium. Alterations in cardiac ECM structure associated with heart failure influence cell-matrix and cell-cell adhesions modifying cell shape and mechanotransduction. The need to understand the cardiac ECM remodelling mechanisms that allow us to identify new therapeutic targets lead us to create biomimetic scaffolds which emulate the structure, topography, mechanics and chemical composition of ECM. Here, we present the development of modulable materials for the manufacturing, by using photopolymerizable materials, of structured hydrogels with myocardium properties of stiffness and elastic modulus in physiological and pathological conditions

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Inkjet‐based technology for microencapsulation of gold nanoparticles within biocompatible hydrogels

Herein, an inkjet‐based technology as a versatile high throughput methodology for the microencapsulation of gold nanoparticles (AuNPs) inside a biocompatible chitosan hydrogel is described. This continuous automated inkjet production approach generates 30 µm diameter polymeric microcapsules and offers a high rate of production and nanoparticle encapsulation efficiency of 14 nm diameter AuNPs, precise control of the microcapsule size, and ease of scale‐up. The hybrid microcapsules demonstrate biocompatible cell‐adhesion properties and resist degradation over a large range of pH, making them particularly relevant for a variety of potential health applications.Authors thank Spanish MICINN Project No. BIO2017‐84246‐C2‐1‐R and DGA and Fondos Feder (Bionanosurf E15_17R). A.A. acknowledges the Ministerio de Educación, Cultura y Deportes of Spanish Government for an FPU Grant No. (FPU014/06249). I.S.S. acknowledges Ministerio de Economía y Competitividad del Gobierno de España for her FPI Grant No. (BES‐2015‐071304).Peer reviewe

Válvula microfluídica, procedimiento de fabricación y usos de la misma

La presente invención se refiere a un procedimiento de fabricación de una válvula microfluídica, que comprende al menos un material mecánicamente inerte a una o más propiedades físico-químicas en el tiempo; e imprimir sobre el sustrato, mediante fabricación aditiva, una disposición de uno o más filamentos de un material con respuesta mecánica a una o más de dichas propiedades físico-químicas en el tiempo. El sustrato de material inerte y los filamentos de material con respuesta mecánica configuran un volumen de paso de un fluido a través de la válvula, donde la sucesión de filamentos del que la variación de uno o más de los parámetros físico-químicos induce una alteración en el orden molecular del LCP, contrayendo o expandiendo sus cadenas poliméricas a lo largo de una dirección longitudinal o transversal de los filamentos, y conduciendo a la reducción o al aumento del volumen de paso de fluido.Peer reviewedConsejo Superior de Investigaciones Científicas (CSIC), Universidad de ZaragozaA1 Solicitud de patente con informe sobre el estado de la técnic