Efficiency analysis of wide band-gap semiconductors for two-level and three-level power converters

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Power devices based on wide band-gap materials are emerging as alternatives to silicon-based devices. These new devices allow designing and building converters with fewer power losses, and are thus more highly efficient than traditional power converters. Among the wide band-gap materials in use, silicon carbide (SiC) and gallium nitride (GaN) devices are the most promising because of their excellent properties and commercial availability. This paper compares the losses produced in two-level and three-level power converters that use the aforementioned technologies. In addition, we assess the impact on the converter performance caused by the modulation technique. Simulation results under various operating points are reported and compared.Peer ReviewedPostprint (author's final draft

Aplicació de gestió (ERP) de projectes i personal pel Centre Tecnològic de Vilanova i la Geltrú

Aquest Projecte Fi de Carrera està destinat a la millora de la gestió de projectes i personal del Centre Tecnològic de Vilanova i la Geltrú (CTVG). El CTVG es relaciona amb empreses de diferents àmbits i els proporciona els seus serveis. Aquests serveis poden ser la creació de diferents treballs. L'objectiu d'aquest projecte és proporcionar un mecanisme de gestió dels processos que van des de la comunicació amb les empreses fins la creació de projectes. Per fer-ho usarem OpenERP, un ERP lliure. Un ERP ens ofereix diferents mòduls operatius que es poden adaptar a les necessitats de diferents empreses. OpenERP ofereix aquesta funcionalitat de forma gratuïta

Análisis de la incidencia de la Covid19 en los patrones de generación de residuos municipales y en las estrategias de gestión en Cataluña

La pandèmia per COVID-19 va submergir el món a un estat d'alarma sanitari que desencadenaria en canvis en l'estil de vida de milions de persones. Les mesures legals preses a Catalunya van obligar a confinar tota la població catalana als seus domicilis entre el 15 de març i el 2 de maig, excepte per a la compra d'aliments i béns essencials, i tots els comerços no essencials van romandre tancats fins a l'1 de juny, amb les associades conseqüències econòmiques i socials, cosa que va comportar un canvi en el comportament dels ciutadans i per tant en la generació de residus municipals. Entre els diferents municipis de Catalunya, s'observen grans diferències en la generació de residus municipals en funció de la quantitat de comerços HORECA, veient els municipis amb més activitat HORECA com els seus residus municipals es redueixen, especialment les fraccions de vidre, matèria orgànica i envasos ; i per altra banda els municipis amb menor activitat HORECA segueixen amb una tendència similar als anys anteriors o lleugerament superior. Els municipis amb menor nombre d'habitants tenen menys canvis que els municipis amb més habitants. Paral·lelament, no s'ha observat la irrupció de nous fluxos de residus a les fraccions resta, malgrat un increment d'envasos de plàstic i metàl·lics. D'altra banda, l'enquesta d'ICTA-UAB mostra que la percepció dels ciutadans de Cerdanyola del Vallès dels seus consums i generació de residus difereixen de la realitat, ja que les xifres consolidades mostren dades de generació de residus molt superiors a les que esperaven els mateixos ciutadans. Finalment, Catalunya ha reduït dràsticament la generació de residus durant l'època de confinament, i en general durant el 2020, per la qual cosa les estratègies implementades focalitzades en la seguretat del treballador i la disminució de la transmissió del virus van ser apropiades.La pandemia por COVID-19 sumergió al mundo a un estado de alarma sanitario el cual desencadenaría en cambios en el estilo de vida de millones de personas. Las medidas legales tomadas en Cataluña obligaron a confinar a toda la población catalana en sus domicilios entre el 15 de marzo y el 2 de mayo, excepto para la compra de alimentos y bienes esenciales, y todos los comercios no esenciales permanecieron cerrados hasta el 1 de junio, con las asociadas consecuencias económicas y sociales, lo que conllevó a un cambio en el comportamiento de los ciudadanos y por lo tanto en la generación de residuos municipales. Entre los distintos municipios de Cataluña, se observan grandes diferencias en la generación de residuos municipales en función de la cantidad de comercios HORECA, viendo los municipios con mayor actividad HORECA como sus residuos municipales se reducen, especialmente las fracciones de vidrio, materia orgánica y envases; y por otro lado los municipios con menor actividad HORECA siguen con una tendencia similar a los años anteriores o ligeramente superior. Los municipios con menor número de habitantes cuentan con menos cambios que los municipios con mayor número de habitantes. Paralelamente, no se ha observado la irrupción de nuevos flujos de residuos en las fracciones resto, a pesar de un incremento de envases de plástico y metálicos. Por otro lado, la encuesta de ICTA-UAB muestra que la percepción de los ciudadanos de Cerdanyola del Vallès de sus consumos y generación de residuos difieren de la realidad, ya que las cifras consolidadas muestran datos de generación de residuos muy superiores a las esperadas por los propios ciudadanos. Finalmente, Cataluña ha redujo drásticamente la generación de residuos durante la época de confinamiento, y en general durante todo 2020, por lo que las estrategias implementadas focalizadas en la seguridad del trabajador y la disminución de la transmisión del virus fueron apropiadas.The COVID-19 pandemic brought the world into a state of health alarm that would trigger lifestyle changes for millions of people. The legal measures taken in Catalonia forced the entire Catalan population to be confined to their homes between March 15 and May 2, except for the purchase of food and essential goods, and all non-essential businesses remained closed until June 1, with the associated economic and social consequences, which led to a change in the behavior of citizens and therefore in the generation of municipal waste. Among the different municipalities of Catalonia, large differences are observed in the generation of municipal waste depending on the number of HORECA businesses, seeing the municipalities with greater HORECA activity as their municipal waste is reduced, especially the fractions of glass, organic matter and packaging; and on the other hand, the municipalities with less HORECA activity continue with a similar trend to previous years or slightly higher. Municipalities with a smaller number of inhabitants have fewer changes than municipalities with a larger number of inhabitants. At the same time, no new waste streams have been observed in the remaining fractions, despite an increase in plastic and metallic packaging. On the other hand, the ICTA-UAB survey shows that the perception of the citizens of Cerdanyola del Vallès of their consumption and waste generation differs from reality, since the consolidated figures show waste generation figures much higher than those expected by the citizens themselves. Finally, Catalonia has drastically reduced waste generation during the confinement period, and in general throughout 2020, so that the strategies implemented focused on worker safety and the reduction of virus transmission were appropriate

Business Process Reengineering based on Measures

Business Process Reengineering (BPR) allows organizations to change their processes in order to improve their activities according to their own objectives. Measurement is needed to evaluate the reengineering process. The Cancer Registry of the Catalan Institute of Oncology (ICO) needs a redesign of some processes. So a systematic review is carried to define the state of the art on the use of metrics in BPR. As a result of the review, the PRiM methodology is selected as the most appropriate for measuring the redesign of the Cancer Registry, which then is modeled using the i* paradigm. Both the “as‐is” model and the “to‐be” model are presented, and metrics are defined to see if the redesign adapts to the expected goals

Nintedanib decreases muscle fibrosis and improves muscle function in a murine model of dystrophinopathy

Duchenne muscle dystrophy (DMD) is a genetic disorder characterized by progressive skeletal muscle weakness. Dystrophin deficiency induces instability of the sarcolemma during muscle contraction that leads to muscle necrosis and replacement of muscle by fibro-adipose tissue. Several therapies have been developed to counteract the fibrotic process. We report the effects of nintedanib, a tyrosine kinase inhibitor, in the mdx murine model of DMD. Nintedanib reduced proliferation and migration of human fibroblasts in vitro and decreased the expression of fibrotic genes such as COL1A1, COL3A1, FN1, TGFB1, and PDGFA. We treated seven mdx mice with 60 mg/kg/day nintedanib for 1 month. Electrophysiological studies showed an increase in the amplitude of the motor action potentials and an improvement of the morphology of motor unit potentials in the animals treated. Histological studies demonstrated a significant reduction of the fibrotic areas present in the skeletal muscles. Analysis of mRNA expression from muscles of treated mice showed a reduction in Col1a1, Col3a1, Tgfb1, and Pdgfa. Western blot showed a reduction in the expression of collagen I in skeletal muscles. In conclusion, nintedanib reduced the fibrotic process in a murine model of dystrophinopathy after 1 month of treatment, suggesting its potential use as a therapeutic drug in DMD patients.España, Ministerio de Economía y Competitividad BFU2016-74975-PEspaña, Instituto Ramón y Cajal PI13/0134

Calibration transfer and drift counteraction in chemical sensor arrays using Direct Standardization

Inherent variability of chemical sensors makes it necessary to calibrate chemical detection systems individually. This shortcoming has traditionally limited usability of systems based on metal oxide gas sensor arrays and prevented mass-production for some applications. Here, aiming at exploring calibration transfer between chemical sensor arrays, we exposed five twin 8-sensor detection units to different concentration levels of ethanol, ethylene, carbon monoxide, or methane. First, we built calibration models using data acquired with a master unit. Second, to explore the transferability of the calibration models, we used Direct Standardization to map the signals of a slave unit to the space of the master unit in calibration. In particular, we evaluated the transferability of the calibration models to other detection units, and within the same unit measuring days apart. Our results show that signals acquired with one unit can be successfully mapped to the space of a reference unit. Hence, calibration models trained with a master unit can be extended to slave units using a reduced number of transfer samples, diminishing thereby calibration costs. Similarly, signals of a sensing unit can be transformed to match sensor behavior in the past to mitigate drift effects. Therefore, the proposed methodology can reduce calibration costs in mass-production and delay recalibrations due to sensor aging. Acquired dataset is made publicly available

A practical method to estimate the resolving power of a chemical sensor array: application to feature selection

A methodology to calculate analytical figures of merit is not well established for detection systems that are based on sensor arrays with low sensor selectivity. In this work, we present a practical approach to estimate the Resolving Power of a sensory system, considering non-linear sensors and heteroscedastic sensor noise. We use the definition introduced by Shannon in the field of communication theory to quantify the number of symbols in a noisy environment, and its version adapted by Gardner and Barlett for chemical sensor systems. Our method combines dimensionality reduction and the use of algorithms to compute the convex hull of the empirical data to estimate the data volume in the sensor response space. We validate our methodology with synthetic data and with actual data captured with temperature-modulated MOX gas sensors. Unlike other methodologies, our method does not require the intrinsic dimensionality of the sensor response to be smaller than the dimensionality of the input space. Moreover, our method circumvents the problem to obtain the sensitivity matrix, which usually is not known. Hence, our method is able to successfully compute the Resolving Power of actual chemical sensor arrays. We provide a relevant figure of merit, and a methodology to calculate it, that was missing in the literature to benchmark broad-response gas sensor arrays

Bioinspired Early Detection through gas flow modulation in chemo-sensory systems

The design of bioinspired systems for chemical sensing is an engaging line of research in machine olfaction. Developments in this line could increase the lifetime and sensitivity of artificial chemo-sensory systems. Such approach is based on the sensory systems known in live organisms, and the resulting developed artificial systems are targeted to reproduce the biological mechanisms to some extent. Sniffing behaviour, sampling odours actively, has been studied recently in neuroscience, and it has been suggested that the respiration frequency is an important parameter of the olfactory system, since the odour perception, especially in complex scenarios such as novel odourants exploration, depends on both the stimulus identity and the sampling method. In this work we propose a chemical sensing system based on an array of 16 metal-oxide gas sensors that we combined with an external mechanical ventilator to simulate the biological respiration cycle. The tested gas classes formed a relatively broad combination of two analytes, acetone and ethanol, in binary mixtures. Two sets of low-frequency and high-frequency features were extracted from the acquired signals to show that the high-frequency features contain information related to the gas class. In addition, such information is available at early stages of the measurement, which could make the technique suitable in early detection scenarios. The full data set is made publicly available to the community

Factorías de Recursos Docentes: un servicio colaborativo de apoyo a la docencia en las Bibliotecas de la UPC

Peer Reviewe

Hacia una estrategia española de producción, certificación y uso de semillas de plantas herbáceas autóctonas

Propuesta para una estrategia española de gestión y certificación de semillas de especies herbáceas autóctonas