Dipòsit Digital de la Universitat de Barcelona

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El Dipòsit Digital de la Universitat de Barcelona és el repositori institucional que conté en format digital els materials derivats de l'activitat docent, investigadora i institucional de la comunitat universitària.

Enviaments recents

Dimensionally and morphologically driven effects of nanomaterials on the enhancement of electroanalytical sensing performance: A review
(Elsevier B.V., 2026-07-28) Huang, Jing; Bastos Arrieta, Julio; Serrano i Plana, Núria; Díaz Cruz, José Manuel
Electrochemical sensors are widely used in environmental monitoring, clinical diagnostics, and food-safety assessment because they can support rapid analysis, relatively low-cost instrumentation, and sensitive detection when sensing interfaces and recognition strategies are appropriately designed. Bare electrodes, however,may show slow electron-transfer kinetics, limited electroactive area, or insufficient stability. Incorporating nanomaterials can address these constraints by modifying charge transport, active-site accessibility, analyte accumulation, and interfacial chemistry. This review uses dimensionality and morphology as operational descriptorsto examine how zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and threedimensional(3D)/hierarchical architectures influence structure-dependent electroanalytical behavior. 0D materials provide discrete catalytic or redox-active sites and, in selected nanoclusters and quantum dots, size dependent electronic effects. 1D architectures can support directional or percolated charge transport, subject to orientation, connectivity, junction resistance, and electrode adhesion. 2D materials provide accessible interfaces, exposed basal, edge, or defect sites, and tunable surface chemistry, including selected ultrathin nanosheetsand nanofilms. 3D/hierarchical architectures regulate analyte-accessible reaction volumes and spatially partition functions: hollow and nanoporous structures organize internal transport, core–shell structures provide radial partitioning, and Janus interfaces provide lateral or anisotropic partitioning.
Dynamical masses of young stellar objects with the VLBA: DYNAMO-VLBA: Trigonometric parallaxes and proper motions of YSOs in Orion
(EDP Sciences, 2026-04-24) Dzib, Sergio; Moo-Herrera, Karla; Ordóñez-Toro, Jazmín; Loinard, Laurent; Kounkel, Marina; Ortiz-León, Gisela N.; Galli, Phillip; Rodríguez, Luis F.; Mioduszewski, Amy; Masqué Saumell, Josep Maria; O'Kelly, Eoin; Forbrich, Jan
We present results from a multi-epoch Very Long Baseline Array (VLBA) survey of compact radio sources in the Orion complex, conducted within both the DYNAMO–VLBA and GOBELINS projects. We detected 216 compact radio sources, of which 58 yielded reliable multi-epoch astrometric solutions. For these sources, we derived trigonometric parallaxes and proper motions with typical precisions of about 0.05 mas and 0.10 mas yr−1, respectively. The measured parallaxes range between 2.26 and 2.65 mas, corresponding to distances of 380–440 pc, and delineate the depth of the Orion star-forming complex. We determined mean distances of 405 ± 16 pc for NGC 2068, 403 ± 5 pc for NGC 2024, 407 ± 12 pc for the σ Orionis region, 388.5 ± 1.7 pc for the Orion Nebula Cluster, and 438 ± 12 pc for L1641. A comparison with Gaia DR3 astrometry for 28 common sources revealed negligible mean parallax offsets (Δϖ= − 0.02 ± 0.01 mas) and small systematic differences in proper motions (∼0.07 mas yr−1), likely due to the residual rotation of the Gaia reference frame. Our results demonstrate the capability of high-precision radio astrometry to map embedded stellar populations and to provide an independent calibration of the Gaia reference system in obscured regions.
Exploring phase effects and ROS contributions in catalytic ozonation ofpolymorphic MnO2-Oxalic acid complexes
(Elsevier B.V., 2025-03-31) Liu, Jiao; Yuan, Xiangjuan; Sans Mazón, Carme
This study investigated the pivotal role of oxalic acid (OA) in promoting the formation of multi-phase MnO2-OA complexes (α-MnO2-OA, β-MnO2-OA, and δ-MnO2-OA), significantly enhancing the efficiency of catalytic ozonation efficiency for pollutants degradation. At a catalyst-to-OA molar ratio of 1:0.8, the ATZ (5 mg L−1) degradation efficiencies within 3 min were 95.09 %, 93.43 %, and 96.71 % for the α-MnO2/OA/O3, β-MnO2/OA/O3, and δ-MnO2/OA/O3 systems, respectively—approximately twice as high as that of O3 alone. Pyrophosphate experiments verified that the formation of MnO2-OA complexes relied on the presence of Mn3+ on the surface of catalysts, which exhibited higher stability and catalytic ozonation ability in acidic conditions. Further probe experiments quantified the contributions of various reactive oxygen species (ROS) in the MnO2-OA complexes mediated catalytic ozonation system. The results indicated that O2•− as dominant species responsible for ATZ removal, followed by •OH, while O3 and 1O2 played comparatively minor roles. Notably, multi-phases MnO2-OA complexes revealed distinct active sites during the catalytic ozonation processes, as identified through a series of characterization techniques. For the α-MnO2-OA complex, more oxygen vacancies were generated on the surface, adsorbing O3 and pollutants for further reaction. For the β-MnO2-OA complex, more manganese vacancies and enhanced lattice oxygen (OL) mobility were key factors contributing to ROS production. As for the δ-MnO2-OA complex, the surface –OH groups acted as the main active site, reacting with O3 to generate more ROS, thus improving ATZ degradation. Overall, this study provides innovative insights into the application of MnO2 in catalytic ozonation.
Gamificación y desarrollo de valores en Educación Física: una situación de aprendizaje de fútbol inspirada en la Kings League en 3.º de ESO
(2026) Basualto Cobaise, Rodrigo; Bofill Ródenas, Ana
[spa] Este estudio analiza la evolución de la cooperación, el respeto y la autorregulación de la competitividad en alumnado de 3.º de ESO tras implementar una situación de aprendizaje gamificada de fútbol inspirada en la Kings League. La intervención, denominada Kings League Educativa, se desarrolló en dos grupos naturales de la escuela Arrels de Barcelona, con 64 estudiantes iniciales y 63 finales. Desde un enfoque mixto y evaluativo, se aplicó durante seis sesiones de Educación Física e incorporó equipos estables, roles, reglas especiales y un sistema de puntuación que combinaba el resultado deportivo con la valoración prioritaria de conductas vinculadas a valores. La evolución del alumnado se valoró mediante un cuestionario pretest-postest adaptado de la MSOS, compuesto por ítems cerrados y preguntas abiertas, una rúbrica de observación sistemática y diarios de aprendizaje, dianas grupales y tickets de salida. Los resultados muestran una tendencia positiva en las dimensiones vinculadas a la deportividad y en las conductas observadas, especialmente en el respeto y la autorregulación de la competitividad. Se concluye que el fútbol, cuando se planifica con intencionalidad pedagógica, gamificación profunda y evaluación formativa y formadora, puede convertirse en una herramienta educativa relevante para promover valores en Educación Física. [eng] This study analyses the evolution of cooperation, respect, and self-regulation of competitiveness among students in the third year of compulsory secondary education after the implementation of a gamified football learning situation inspired by the Kings League. The intervention, called the Educational Kings League, was carried out in two natural groups at Arrels School in Barcelona, with an initial sample of 64 students and a final sample of 63. Using a mixed and evaluative approach, it was implemented over six Physical Education sessions and incorporated stable teams, roles, special rules, and a scoring system that combined sporting results with the prioritised assessment of value-related behaviours. Students’ development was assessed through a pretest-posttest questionnaire adapted from the MSOS, composed of closed items and open-ended questions, a systematic observation rubric, learning diaries, group target diagrams, and exit tickets. The results show a positive trend in the dimensions related to sportsmanship and in the behaviours observed, especially regarding respect and self-regulation of competitiveness. It is concluded that football, when planned with pedagogical intentionality, deep gamification, and formative and learning-oriented assessment, can become a relevant educational tool for promoting values in Physical Education.
Complete antihistamine degradation in wastewater matrix using a metal-free N-doped carbon with superior electrocatalytic performance for in-situ $$H_2O_2$ production
(Elsevier B.V., 2025-01-11) Zhao, Lele; Mazzucato, Marco; Lanzalaco, Sonia; Parnigotto, Mattia; Cabot Julià, Pere-Lluís; Durante, Christian; Sirés Sadornil, Ignacio
A new gas-diffusion electrode (GDE) has been developed and optimized to apply the heterogeneous electro-Fenton (EF) process to the degradation of the antihistamine diphenhydramine. The complete removal of this hazardous drug pollutant was achieved within only 120 min in actual urban wastewater at pH 5.9. Nitrogendoped carbon electrocatalysts were first synthesized by direct pyrolysis of blends of commercial Vulcan carbon and melamine as nitrogen dopant. A radar chart was proposed to correlate the tested physicochemical and electrochemical properties. A well-balanced surface area, mesopores volume and defective carbon content were critical to ensure the highest activity (Eonset = 0.38 V vs. RHE) and selectivity (n ~ 2, yH2O2 ~ 95.3%) for twoelectron oxygen reduction reaction (ORR), which allowed the efficient in-situ production of H2O2 as •OH precursor. N-doping (10.5 wt%), along with the presence of pyrrolic N (3.5%), are also key factors to explain the enhancement. GDEs fabricated with the optimal electrocatalyst (71.4 wt% melamine content) were capable of accumulating up to ~35 mM H2O2 within 5 h, outperforming the commercial GDEs. This work evidences theinterplay of physicochemical and electrocatalytic parameters in H2O2-based advanced water treatment, demonstrating that it is possible to envisage a more efficient and greener tertiary wastewater treatment.