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L'erosió de les platges
No full textXerrada a càrrec de Josep Pintó, doctor en Geografia, on exposa les causes principals de l'erosió a les platges i planteja una sèrie de solucions
Verification of the dependability of an improved negative-sequence based shunt reactor protection in a power grid with inverter-based resources (IBR)
No full textThis thesis validates a simplified negative-sequence–based protection scheme for turn-to-turn faults (TTFs) in shunt reactors and benchmarks its dependability in both conventional synchronousmachine grids and inverter-based resource (IBR) environments. A 500 MW transmission test bench—mark connected to a 50 MW offshore wind farm through land/sea cables, and shuntreactor compensation—was modeled. The farm Model was implemented in three different ways: (i) a conventional three-phase voltage source (Model I), (ii) a grid-following inverter (Model II), and (iii) a grid-following inverter with negative-sequence injection (Model III). The protection algorithm measures terminal currents, extracts their negative-sequence component, converts it to per-unit, and issues a trip when a fixed threshold is exceeded. Dependability was assessed for two fault severities (TTF = 1 % and 0.065 %) and two grid strengths (SCR = 10 and 1). Results show that the terminal negative-sequence current |I2|—and hence sensitivity—declines with decreasing SCR, yet remains above the detection threshold for SCR ≥ 0.1. At TTF = 1 %, all models tripped reliably; Model I generated the largest |I2| in every case, while Model III surpassed Model II in weak grids. At TTF = 0.065 %, detection margins narrowed: Model II edged Model III in strong grids, but Model III regained superiority under weak grids despite Moving-Average-Filter limitations. A practical lower-sensitivity bound was identified at TTF ≈ 0.035% for SCR = 5. Parametric sweeps confirmed near-linear |I2| trends versus both TTF %, with Model I exhibiting the steepest gradients. Overall, Model I remains the most robust, Model III is the best IBR solution—approaching Model I in weak grids or at higher fault levels—and Model II is adequate only in strong grids. These findings demonstrate that the proposed algorithm can dependably detect TTFs down to 0.065 % even in inverter-dominated, low-SCR networks and highlight the value of negativesequence injection for future IBR protection strategies.Outgoin
Parametric study of jet fires simulation in FDS using a spray-of-particles approach
No full textLifted turbulent jet flames are observed in industry accidental scenarios and can lead to undesirable consequences. The results from a lifted, horizontal, sonic, propane jet fire experiment were used in this study to compare against simulation results obtained using FDS. The release was first simulated as a leak using FLACS software to determine the velocity within the lift-off region. Then, the jet fire was simulated considering release at a lift-off location along the nozzle axis where the Mach number was valid for FDS application. The horizontal jet fire was simulated in FDS as a spray of particles, and the effects of two input variables required for the spray approach (i.e. spray angle and particle diameter) were assessed in relation to the total flame reach, flame height, flame area, and flame temperature profile. It was observed that the best result considering all output variables of interest was obtained using a spray angle of 5° and a particle diameter of 500 µm. Additionally, it was corroborated that FDS, even with flow velocities corresponding to low Mach numbers, cannot capture lifted flames. Further work should be done to investigate if a finite-rate chemistry model should be considered and if the time integration approach for mixing and reaction in FDS should be modified.This research was partially funded by: PID2020-114766RB-100 and PID2023-150607OB-I00 (MCIN/AEI), and 2021_SGR_00251 (Generalitat de Catalunya). A. Àgueda is a Serra Hunter Fellow.Postprint (published version
Lagoons, oases, and meanders: spaces for reflection in alternative learning about Architecture
No full textThe purpose of this text is to highlight meaningful architectural learning experiences for students, which are brought together and linked in an active and autonomous dimension of the general processes that define the corresponding course programs and curricula. This kind of non-literality, understood as an opening, allows us to refer to academic activities or explorations in which the outcome of an action, in the broadest sense, triggers a reflection that transcends learning. Embodied in first-year workshop exercises, an annual course with a modular organization, it allows for successive and diverse spaces for exploration. The methodology consists of asking a question and thereby promoting an insertion into a research topic based on a triggering experience, whether spatial, material, or phenomenological. The development of the exercises depends on the progress of the students' discoveries.El presente texto tiene como objetivo visibilizar experiencias de aprendizaje de arquitectura significativas para el estudiantado, las cuales se reúnen y relacionan en una dimensión activa y autónoma de los procesos generales que definen los programas de asignaturas y los planes de estudio correspondientes. Esta suerte de no literalidad, entendida como una apertura, permite referirse a actividades o exploraciones académicas en las que el devenir desde una acción, en el más amplio sentido, detona una reflexión que trasciende en el aprendizaje. Encarnado en ejercicios del taller de primer año, asignatura de régimen anual con organización modular, permite realizar sucesivos y diversos espacios de exploración. La metodología consiste en realizar una pregunta y promover con ello una inserción en un tema de investigación a partir de una experiencia detonante; ya sea de orden espacial, material o fenomenológico. El desarrollo de los ejercicios depende del progreso en los descubrimientos de los estudiantes.Peer Reviewe
Optimal design of single point moorings for a weathervaning floating wind twin-turbine platform in real bathymetries
No full textThis article presents the design and optimization of the mooring system for a floating wind platform inspired by W2Power, which incorporates two wind turbines on a semi-submersible structure that weathervanes using a single-point mooring (SPM) system. Although several industrial concepts have adopted SPM configurations, research on their performance remains limited. This work addresses that gap by developing and applying a set of optimization strategies for the mooring system of such a platform using OrcaFlex, with the objective of minimizing the capital expenditure while satisfying Ultimate Limit State (ULS) and Fatigue Limit State (FLS) cases. The methodology was tested across two distinct marine environments: the Atlantic (Gran Canaria, GC-1) and the Mediterranean (Catalonia, LEBA-1), both characterized by their irregular bathymetry. In Catalonia, the environmental conditions are almost omnidirectional, while the platform in Gran Canaria is exposed to highly unidirectional loads. The article presents the most cost-effective solution for single-point moorings with three, four, and five lines in each case. Results demonstrate the viability of SPM-based floating wind systems with twin-turbines under diverse site conditions.The research leading to these results has received financial support from the Spanish Ministry of Science and Innovation, subsidized by CDTI through the TRANSMISIONES 2023 program under the OPTIMAR project with grant agreement PLEC2023-010352.Peer ReviewedPostprint (published version
Nanotechnology in biomedical applications: a perspective
No full textNanotechnology has emerged as a powerful enabler of innovation in the biomedical field, offering novel solutions for drug delivery, diagnostics, and regenerative medicine. This perspective highlights key developments in the use of nanoscale materials and devices to enhance therapeutic efficacy, enable early disease detection, and support tissue engineering. It also addresses the challenges related to nanotoxicology, manufacturing, and regulation that must be overcome to fully integrate nanotechnology into clinical practice. Looking ahead, the fusion of nanotechnology with emerging fields such as artificial intelligence and personalized medicine promises to revolutionize healthcare. Continued interdisciplinary collaboration and responsible innovation will be essential to unlocking its full potential.Postprint (published version
Paisatge i bauxa: simbiosi al marge del torrent: projecte per a la reactivació dels marges d’Es Riuet
No full textEl projecte se situa als marges d’Es Riuet, a Porto Cristo, una zona actualment degradada però amb un fort potencial paisatgístic i social. Es proposa la reactivació d’aquest espai mitjançant un conjunt d’equipaments d’oci nocturn –discoteca, bar musical, bar exterior i espai jove– que conviuen amb la renaturalització del torrent i la creació d’un espai públic actiu durant el dia. L’objectiu és establir una simbiosi entre paisatge i bauxa, entre natura i activitat urbana, que afavoreixi l’apropiació ciutadana del marge del torrent.
El projecte s’articula en planta baixa i adopta una organització radial entorn d’un escenari exterior, amb franges de serveis construïdes amb formigó que alternen amb les sales principals. Una pèrgola lleugera actua com a transició cap al paisatge natural, tot oferint un recorregut d’entrada i relació amb els espais exteriors. L’arquitectura es fon amb el context, emprant sistemes constructius que responen a criteris acústics, ambientals i d’integració territorial
ICMT.1: primer centro sanitario - tecnológico de la UPC para la docencia, la investigación y la divulgación de la medicina en Terrassa
No full textUna nova infraestructura urbana per a la docència, la investigació i la divulgació de la medicina a Terrassa.Una nueva infraestructura urbana para la docencia, la investigación y la divulgación de la medicina en Terrassa.A cutting-edge urban facility for medical education, research, and public outreach in Terrassa
Long-term performance and operational factors of a pilot-scale bioscrubber for landfill biogas desulfurization
No full textLandfill biogas is a renewable energy source, but its utilization is hindered by hydrogen sulfide, a corrosive and toxic compound. Anoxic biodesulfurization using nitrified landfill leachate as a sustainable nitrate source provides a cost-effective and circular strategy for H2S removal. This study investigates the long-term performance of anoxic biodesulfurization of landfill biogas using a pilot-scale bioscrubber (1 m3) fed with nitrified landfill leachate over 61 weeks. A total volume of 264,812 m3 of biogas was treated, achieving an average H2S removal efficiency (RE) of 85.2 ± 10.1 %. Optimal performance, reaching 97 ± 3 % RE, was obtained at an inlet load of 7.71 ± 0.16 gS-H2S m-3 h-1, pH 7.98 ± 0.07, and temperature 30.58 ± 3.16 °C. The research examined the impact of key operational parameters: oxidation-reduction potential (ORP) control influenced sulfur selectivity but proved challenging to stabilize; temperature showed a strong correlation with performance, with efficiency generally declining when reactor values dropped below ~22 °C; and pH substantially affected performance, with efficiency decreasing at more acidic values (RE below 60 %, pH below 7.5). Microbial analysis revealed a dynamic bacterial community adapting to operational conditions, with Thioalkalispira-Sulfurivermis (relative abundance above 18 %) identified as the predominant functional genus. The system demonstrated resilience to operational disturbances like recirculation pump failure and fluctuations in biogas flow rate. This study provides valuable insights into the practical application of anoxic bioscrubbers for landfill biogas biodesulfurization, highlighting controlling factors and offering a foundation for enhancing the efficiency and sustainability of biogas purification technologies under real-world constraints.This study is supported by the Green Fund and the LIFE project (EC): “Sustainable biogas purification system in landfills and municipal solid wastes treatment plants (LIFE BIOGASNET)”, LIFE18 ENV/ES/000426, ad from the infrastructure project EQC2018-004212-P funded by the Spanish State Research Agency (AEI), Ministry of Science, Innovation and Universities, and co-financed by the European Regional Development Fund (FEDER).
We thank Helena Torrell Galceran and Adrià Cereto-Massagué from the Genomics and Bioinformatics facility of the Centre for Omic Sciences (COS) Joint Unit of the Universitat Rovira i Virgili-Eurecat, for their contribution to Next Generation Sequencing (NGS).Peer ReviewedPostprint (published version
