Shock capturing techniques for hp-adaptive finite elements

The aim of this work is to propose an hp-adaptive algorithm for discontinuous Galerkin methods that is capable to detect the discontinuities and sharp layers and avoid the spurious oscillation of the solution around them. In order to control the spurious oscillations, artificial viscosity is used with the particularity that it is only applied around the layers where the solution changes abruptly. To do so, a novel troubled-cell detector has been developed in order to mark the elements around those layers and to impose linear order in them. The detector takes advantage of the evolution of the value of the gradient through the adaptive process.Peer ReviewedPostprint (published version

On discrete maximum principles for discontinuous Galerkin methods

The aim of this work is to propose a monotonicity-preserving method for discontinuous Galerkin (dG) approximations of convection–diffusion problems. To do so, a novel definition of discrete maximum principle (DMP) is proposed using the discrete variational setting of the problem, and we show that the fulfilment of this DMP implies that the minimum/maximum (depending on the sign of the forcing term) is on the boundary for multidimensional problems. Then, an artificial viscosity (AV) technique is designed for convection-dominant problems that satisfies the above mentioned DMP. The noncomplete stabilized interior penalty dG method is proved to fulfil the DMP property for the one-dimensional linear case when adding such AV with certain parameters. The benchmarks for the constant values to satisfy the DMP are calculated and tested in the numerical experiments section. Finally, the method is applied to different test problems in one and two dimensions to show its performance.Preprin

Ús de fongs per a la degradació de filtres solars

Els compostos que trobem en cremes solars o d'altres productes i que s'utilitzen per reduir l'efecte de les radiacions ultraviolades en el nostre cos s'alliberen cada vegada més al medi ambient, sense que els procediments habituals per eliminar compostos no desitjats, com les depuradores, estiguin encara preparats per eliminar-los. Aquesta investigació, duta a terme al Departament d'Enginyeria Química de la UAB en un projecte en col·laboració amb l'IDAEA-CSIC, ha utilitzat fongs ligninolítics per eliminar aquests productes. La investigació conclou que aquests fongs són prometedors per a l'eliminació d'aquests nous contaminats però que encara som lluny de la seva implementació definitiva.Los compuestos que podemos encontrar en cremas solares o de otros productos y que se utilizan para reducir el efecto de las radiaciones ultravioletas en nuestro cuerpo se liberan cada vez más al medio ambiente, sin que los procedimientos habituales para eliminar compuestos no deseados, como las depuradoras, estén aún preparados para eliminarlos. Esta investigación, llevada a cabo en el Departamento de Ingeniería Química de la UAB en un proyecto en colaboración con el IDAEA-CSIC, ha utilizado hongos ligninolíticos para eliminar estos productos. La investigación concluye que estos hongos son prometedores para la eliminación de estos nuevos contaminantes pero que todavía estamos lejos de su implementación definitiva.The compounds found in sunscreens and other products used to reduce the effect of ultraviolet radiations in our body are released into the environment, without the usual procedures to remove unwanted compounds such as treatment facilities, are prepared to remove them. This research, carried out at the Department of Chemical Engineering at UAB in collaboration with the IDAEA-CSIC, has used ligninolytic fungi to remove these products. This research concludes that these fungi are promising for the elimination of these new pollutants but we are still far from its implementation

Design and Implementation of Acoustic Source Localization on a Low-Cost IoT Edge Platform

The implementation of algorithms for acoustic source localization on edge platforms for the Internet of Things (IoT) is gaining momentum. Applications based on acoustic monitoring can greatly benefit from efficient implementations of such algorithms, enabling novel services for smart homes and buildings or ambient-assisted living. In this context, this brief proposes extreme low-cost sound source localization system composed of two microphones and the low power microcontroller module ESP32. A Direction-Of-Arrival (DOA) algorithm has been implemented taking into account the specific features of this board, showing excellent performance despite the memory constraints imposed by the platform. We have also adapted off-the-shelf lowcost microphone boards to the input requirements of the ESP32 Analog-to-Digital Converter. The processing has been optimized by leveraging in parallel both cores of the microcontroller to capture and process the audio in real time. Our experiments expose that we can perform real-time localization, with a processing time below 3.3 ms.This work was supported in part by the Spanish Government under Grant TIN2017-82972-R, Grant ESP2015-68245-C4-1-P, and Grant RTI2018-097045-B-C21, and in part by the Valencian Regional Government under Grant PROMETEO/2019/109

Interpretation of cyclic voltammetry measurements of thin semiconductor films for solar fuel applications

A simple model is proposed that allows interpretation of the cyclic voltammetry diagrams obtained experimentally for photoactive semiconductors with surface states or catalysts used for fuel production from sunlight. When the system is limited by charge transfer from the traps/catalyst layer and by detrapping, it is shown that only one capacitive peak is observable and is not recoverable in the return voltage scan. If the system is limited only by charge transfer and not by detrapping, two symmetric capacitive peaks can be observed in the cathodic and anodic directions. The model appears as a useful tool for the swift analysis of the electronic processes that limit fuel production.The research leading to these results is supported by Universitat Jaume I Project P1·1B2011-50

Use of stable isotope probing to assess the fate of emerging contaminants degraded by white-rot fungus

The widespread of emerging contaminants in the environment and their potential impact on humans is a matter of concern. White-rot fungi are cosmopolitan organisms able to remove a wide range of pharmaceuticals and personal care products (PPCP) through cometabolism (i.e. laccases and peroxidases) or detoxification mechanisms (i.e. cytochrome P450 system). However, the use of PPCP as carbon source for these organisms is largely unexplored. Here, we used carbon stable isotope tracer experiments to assess the fate of anti-inflammatory diclofenac (DCF) and UV filter benzophenone-3 (BP3) during degradation by Trametes versicolor. The comparison between carbon isotopic composition of emitted carbon dioxide from 13C-labelled DCF ([acetophenyl ring-13C6]-DCF) and 13C-BP3 ([phenyl-13C6]-BP3) versus their 12C-homologue compounds showed mineralization of about 45% and 10% of the 13C contained in their respective molecules after 9 days of incubation. The carbon isotopic composition of the bulk biomass and the application of amino acid-stable isotope probing (SIP) allowed distinguishing between incorporation of 13C from BP3 into amino acids, which implies the use of this emerging contaminant as carbon source, and major intracellular accumulation of 13C from DCF without implying the transformation of its labelled phenyl ring into anabolic products. A mass balance of 13C in different compartments over time provided a comprehensive picture of the fate of DCF and BP3 across their different transformation processes. This is the first report assessing biodegradation of PPCP by SIP techniques and the use of emerging contaminants as carbon source for amino acid biosynthesis

Uso del modelo sistémico complejo para la mejora de la formación permanente del profesorado de los campos de aprendizaje

La investigación ha sido realizada en el marco de un curso de formación del profesorado iniciado el año 2006 dirigido a los equipos educativos de los Campos de Aprendizaje (CdA). El objetivo es analizar el modelo de ciencia que los educadores tienen y transmiten mediante los contenidos de las actividades y los materiales didácticos. Los fundamentos teóricos parten del paradigma de la complejidad, como marco orientador de pensamiento, acción y ética; y del aprendizaje a través de modelos mentales. En un marco de Educación Ambiental (EA), partiendo del Modelo Sistémico Complejo (MSC), se han establecido unas categorías para analizar el grado de complejidad de los materiales mencionados

Water Oxidation at Hematite Photoelectrodes with an Iridium-Based Catalyst

The iridium complex [Cp*Ir(H2O)3](SO 4) was used as an organometallic source for the electrodeposition of iridium oxide onto Fe2O3. The new iridium-containing electrode allowed us to study the coupling between the photocatalytic properties of hematite and the electrocatalytic properties of the iridium-based material. A cathodic shift of the photocurrent for water oxidation upon electrodeposition of the iridium complex was observed, which increased with increasing surface concentration of IrOx on Fe2O3. The shift for the highest surface concentration of iridium tested amounts to 300 mV at 200 μA·cm-2 current density. The catalytic mechanism of the IrOx layer was unveiled by impedance spectroscopy measurements fitted to a physical model and can be explained on the basis of a highly capacitive layer, which enhances charge separation and stores photogenerated holes at Fe2O3, subsequently oxidizing water. These findings improve our understanding of the mechanism of water oxidation by heterogeneous Ir-based catalysts coupled to semiconductor electrodesJ.B. acknowledges support by projects from Ministerio de Economía y Competititvidad (MINECO) of Spain (Consolider HOPE CSD2007-00007) and Generalitat Valenciana (PROMETEO/2009/058). F.F.S. thanks the funding of University Jaume I- Bancaixa (Grant P1·1B2011-50). S.G. acknowledges support by MINECO of Spain under the Ramon y Cajal programme. Mrs. Encarna Blasco from the Instituto Tecnológico de Cerámica is acknowledged for carrying out the structural characterization by XPS. The SCIE of Universidad de Valencia is acknowledged for the SEM images

Hydrolysis and methanogenesis in UASB-AnMBR treating municipal wastewater under psychrophilic conditions: Importance of reactor configuration and inoculum

Three upflow anaerobic sludge blanket (UASB) pilot scale reactors with different configurations and inocula: flocculent biomass (F-UASB), flocculent biomass and membrane solids separation (F-AnMBR) and granular biomass and membrane solids separation (G-AnMBR) were operated to compare start-up, solids hydrolysis and effluent quality. The parallel operation of UASBs with these different configurations at low temperatures (9.7 ± 2.4°C) and the low COD content (sCOD 54.1 ± 10.3 mg/L and pCOD 84.1 ± 48.5 mg/L), was novel and not previously reported. A quick start-up was observed for the three reactors and could be attributed to the previous acclimation of the seed sludge to the settled wastewater and to low temperatures. The results obtained for the first 45 days of operation showed that solids management was critical to reach a high effluent quality. Overall, the F-AnMBR showed higher rates of hydrolysis per solid removed (38%) among the three different UASB configurations tested. Flocculent biomass promoted slightly higher hydrolysis than granular biomass. The effluent quality obtained in the F-AnMBR was 38.0 ± 5.9 mg pCOD/L, 0.4 ± 0.9 mg sCOD/L, 9.9 ± 1.3 mg BOD5/L and <1 mg TSS/L. The microbial diversity of the biomass was also assessed. Bacteroidales and Clostridiales were the major bacterial fermenter orders detected and a relative high abundance of syntrophic bacteria was also detected. Additionally, an elevated abundance of sulfate reducing bacteria (SRB) was also identified and was attributed to the low COD/SO42– ratio of the wastewater (0.5). Also, the coexistence of acetoclastic and hydrogenotrophic methanogenesis was suggested. Overall this study demonstrates the suitability of UASB reactors coupled with membrane can achieve a high effluent quality when treating municipal wastewater under psychrophilic temperatures with F-AnMBR promoting slightly higher hydrolysis rate

RITA: a 1U multi-sensor Earth observation payload for the AlainSat-1

The Remote sensing and Interference detector with radiomeTry and vegetation Analysis (RITA) is one of the Remote Sensing payloads selected as winners of the 2nd GRSS Student Grand Challenge in 2019, to fly on board of the 3U AlainSat-1. This CubeSat is being developed by the National Space Science and Technology Center (NSSTC), United Arab Emirates University. RITA has been designed as an academic mission, which brings together students from different backgrounds in a joint effort to apply very distinct sensors in an Earth Observation mission, fusing their results to obtain higher-accuracy measurements. The main payload used in RITA is a Total Power Radiometer such as the one on board the FSSCat mission. With these radiometric measurements, soil moisture and ice thickness will be obtained. To better characterize the extensive Radio-Frequency Interferences received by EO satellites in protected bands, several RFI Detection and Classification algorithms will be included to generate a worldwide map of RFI. As a novel addition to the 3Cat family of satellites and payloads, a hyper-spectral camera with 25 bands ranging from 600 to 975 nm will be used to obtain several indexes related to vegetation. By linking these measurements with the soil moisture obtained from the MWR, pixel downscaling can be attempted. Finally, a custom- developed LoRa transceiver will be included to provide a multi-level approach to in-situ sensors: On-demand executions of the other payloads will be able to be triggered from ground sensors if necessary, as well as simple reception of other measurements that will complement the ones obtained on the satellite. The antennas for both the MWR and the LoRa experiments have been developed in-house, and will span the entirety of one of the 3U sides of the satellite. In this work, the latest development advances will be presented, together with an updated system overview and information about the operations that will be conducted. Results obtained from the test campaign are also presented in the conference