Novel environmental catalysts prepared with residual metals on bioactive nanomaterials

Volatile organic compounds (VOCs), which are emitted from many industrial processes and transport activities, constitute an important concern for the scientific community due to their role in atmospheric pollution and subsequent impact on human health. Among the various methods that can be applied to efficiently control VOCs emissions, catalytic oxidation over solid catalysts seems to be the most efficient and cost-effective technology. Catalysts used for the treatment of gas streams contaminated with VOCs are mostly based on noble metals. Using low cost transition metals such as chromium to replace the noble metal in the catalysts is quite desirable in terms of economical and practical consideration. The catalytic oxidation of 1,2-dichlorobenzene was investigated over NaY and NaX zeolites, loaded with chromium through the action of a robust biosorption system consisting of a bacterial biofilm supported on the zeolites. The results of biosorption showed that the maximum metal removal efficiency was 20%, in both systems based on NaYor NaX, starting from solutions with chromium(VI) concentrations ranging from 50 to 250 mgCr/L [1]. The bacterial biofilm, Arthrobacter viscosus, supported on the zeolite reduces Cr(VI) to Cr(III). The Cr(III) is retained in the zeolite by ion exchange. The new catalysts were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (XRD) and thermal analysis (TGA). These catalysts, Cr/FAU, prepared through this new procedure present good activity and selectivity for 1,2-dichlorobenzene oxidation in wet air at 350oC. The study was extended to the oxidation of ethyl acetate and to the oxidation of ethanol [2]

Quantum and classical communications on shared infrastructure

Future communications networks not only should enable massive exchange of classical bits, but also the transmission of quantum bits on which many quantum applications rely. This will be the key to offering quantum technologies in a cost-efficient way, and it should encompass the integration of quantum and classical networks at the core of existing optical communications networks, as well as at the access end of such networks. In this work, we cover a range of proposals that enable such an integration for one of the imminent applications of quantum technologies, i.e., quantum key distribution (QKD), by which users can securely exchange a secret key for their cryptographic needs. This will include using wavelength division multiplexing techniques to send quantum and classical data on the same fiber as well as wireless access for QKD users to passive optical networks. In each case, we explore optimal arrangements to find the best way forward for an amicable coexistence

Heavy metals transport in typical portuguese loamy sand soils

Illegal discharges are of great concern among industry activities, since they occur under uncontrolled conditions. In most cases, effluents are acidic and the concentrations of heavy metals are very high. With this in mind, the main goal of this study was to evaluate the sorption of two of the most toxic heavy metals, Cr(VI) and Pb(II), in those conditions. A loamy sand soil was collected in Oporto, Portugal. Batch equilibrium and kinetic sorption experiments were performed using both metals solutions, with concentrations among 50 mg L-1 and 200 mg L-1, at pH 2 and 5, between 2 h and 288 h. To evaluate the sorption equilibrium, eight isotherm models were fitted. Better adjustments were observed for the Redlich-Peterson and Khan models for the adsorption of chromium (R2 = 0.99), and of lead (R2 = 0.99), respectively. The sorption kinetics was evaluated using three models – Elovich, Pseudo first order and an empirical power function. The retention of lead was almost instantaneous and the empirical power function described better the sorption kinetics of chromium (0.89 < R2 < 0.99). In addition, flow experiments were performed with effluents of both metals (50 mg L-1) at pH 2 and 5, for about 90 h. Results revealed a high retention of chromium, and a weak retention of lead, for low pH values. FTIR analyses to the columns samples revealed that clay minerals have an important role in the retention of both metals

Finite-key analysis for memory-assisted decoy-state quantum key distribution

Memory-assisted quantum key distribution (MA-QKD) systems are among novel promising solutions that can improve the key-rate scaling with channel loss. By using a middle node with quantum storage and measurement functionalities, they offer the same key-rate scaling with distance as a single-node quantum repeater. However, the distance at which they can surpass the nominal key rate of repeaterless systems, in terms of bits per second, is typically long, owing to the efficiency and/or interaction time issues when one deals with quantum memories. This crossover distance can be a few hundred kilometres, for instance, when one relies on the exchange of infinitely many key bits for the key-rate analysis. In a realistic setup, however, we should account for the finite-key effects in our analysis. Here, we show that accounting for such effects would actually favour MA-QKD setups, by reducing the crossover distance to the regime where realistic implementations can take place. We demonstrate this by rigorously analysing a decoy-state version of MA-QKD, in the finite-key regime, using memory parameters already achievable experimentally. This provides us with a better understanding of the advantages and challenges of working with memory-based systems

Inverse Low Gain Avalanche Detectors (iLGADs) for precise tracking and timing applications

Low Gain Avalanche Detector (LGAD) is the baseline sensing technology of the recently proposed Minimum Ionizing Particle (MIP) end-cap timing detectors (MTD) at the Atlas and CMS experiments. The current MTD sensor is designed as a multi-pad matrix detector delivering a poor position resolution, due to the relatively large pad area, around 1 $mm^2$; and a good timing resolution, around 20-30 ps. Besides, in his current technological incarnation, the timing resolution of the MTD LGAD sensors is severely degraded once the MIP particle hits the inter-pad region since the signal amplification is missing for this region. This limitation is named as the LGAD fill-factor problem. To overcome the fill factor problem and the poor position resolution of the MTD LGAD sensors, a p-in-p LGAD (iLGAD) was introduced. Contrary to the conventional LGAD, the iLGAD has a non-segmented deep p-well (the multiplication layer). Therefore, iLGADs should ideally present a constant gain value over all the sensitive region of the device without gain drops between the signal collecting electrodes; in other words, iLGADs should have a 100${\%}$ fill-factor by design. In this paper, tracking and timing performance of the first iLGAD prototypes is presented.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of Instrumentation, February 18-22, 2019, Vienna, Austri

Twin-Field Quantum Key Distribution with Fully Discrete Phase Randomization

Twin-field (TF) quantum key distribution (QKD) can overcome fundamental secret-key-rate bounds on point-to-point QKD links, allowing us to reach longer distances than ever before. Since its introduction, several TFQKD variants have been proposed, and some of them have already been implemented experimentally. Most of them assume that the users can emit weak coherent pulses with a continuous random phase. In practice, this assumption is often not satisfied, which could open up security loopholes in their implementations. To close this loophole, we propose and prove the security of a TFQKD variant that relies exclusively on discrete phase randomization. Remarkably, our results show that it can also provide higher secret-key rates than an equivalent continuous-phase-randomized protocol

Audiovisual resources for the teaching of foreign languages

Los recursos audiovisuales ocupan un papel relevante en la vida de los jóvenes. El uso combinado de imagen y sonido contribuye a fomentar las habilidades lingüísticas, por ello, es recomendable contemplar estos recursos en la enseñanza de la lengua extranjera. Este trabajo tiene como finalidad analizar el uso y el impacto de las canciones como recurso audiovisual y su utilidad en la enseñanza de la lengua extranjera en alumnado de edades comprendidas entre 12 y 16 años. Para ello, se ha optado por una revisión sistemática de tipo cualitativo donde se utilizaron técnicas de análisis documental, siguiendo las recomendaciones de Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Se realizó una búsqueda y selección de fuentes mediante 4 bases de datos obteniéndose un total de 33.689 registros. Atendiendo a los criterios de inclusión y exclusión: pertinencia, variedad, calidad y duplicidad se realizó un cribado quedando un total de 19 artículos que respondían al objetivo del estudio. Tras un proceso de codificación la información fue categorizada en tres dimensiones: lingüística, intercultural y motivacional. Las conclusiones marcan una tendencia en el uso de los recursos audiovisuales como las canciones con objetivos lingüísticos y/o motivacionales dejando en un segundo plano su contribución al desarrollo del conocimiento intercultural.Audiovisual resources play an important role in the lives of young people. The combined use of image and sound contributes to the development of language skills, so it is advisable to consider these resources in foreign language teaching. The purpose of this paper is to analyze the use and impact of songs as an audiovisual resource and its usefulness in foreign language teaching for students aged 12 to 16. For this purpose, we have opted for a qualitative systematic review using documentary analysis techniques, following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A search and selection of sources was carried out using 4 databases, obtaining a total of 33,689 records. In accordance with the inclusion and exclusion criteria: relevance, variety, quality and duplicity, a screening was carried out, leaving a total of 19 articles that met the objective of the study. After a coding process, the information was categorized into three dimensions: linguistic, intercultural, and motivational. The conclusions show a tendency to use audiovisual resources such as songs for linguistic and/or motivational purposes, leaving in the background their contribution to the development of intercultural knowledge in the background

Flipped classroom in primary education teacher’s degree: strength and weakness

[EN] This article presents the results of an innovation experience carried out with first year students of the Primary Education Teacher’s Degree. Based on global trends in favour of curricular methodologies to encourage the development of autonomous and collaborative learning capacities in students, a group of teacher’s members of the Educational Innovation Group EIEGID, who teach in the subject School Organization and Resources in Education, has sought a progressive graduation in the difficulty and prominence to be assumed by the students in the learning tasks. The aim was to overcome the dichotomy of theoretical classes and practical classes, contemplating different methodologies, but sharing their features: foster student autonomy, seek motivation, take risks and develop alternative responses, promoting responsibility, with options to experiment and encourage the development of an attitude of permanent improvement. To do this, tasks are proposed that allowed to face unforeseen events, t[ES] Este artículo presenta los resultados de una experiencia de innovación realizada con alumnos de primer curso del Grado de Maestro de Educación Primaria. Partiendo de las tendencias globales a favor del fomento de capacidades de aprendizaje autónomo y colaborativo, un grupo de profesores miembros del Grupo de Innovación Docente EIE-GID, ha buscado una graduación progresiva en la dificultad y protagonismo a asumir por el alumnado en las tareas de aprendizaje. Se busca superar la dicotomía de clases teóricas y clases prácticas, empleando metodologías diversas, pero que comparten entre sus rasgos: fomentar la autonomía del alumno, procurar la motivación, adopción de riesgos y elaboración de respuestas alternativas, promoviendo responsabilidad, con opciones de experimentar y estimular el desarrollo de una actitud de superación permanente. Para ello, se plantean tareas que permiten hacer frente a acontecimientos imprevistos, tomar iniciativas, ser responsables y autónomos, movilizar recursosGarcía Hernández, M.; Porto Currás, M.; Hernández Valverde, F. (2019). El aula invertida con alumnos de primero de magisterio: fortalezas y debilidades. REDU. Revista de Docencia Universitaria. 17(2):89-106. https://doi.org/10.4995/redu.2019.11076OJS89106172Ato, M. y Vallejo, G. (2007). Diseños experimentales en psicología. Madrid: Pirámide.Baepler, P.; Walker, J.& Driessen, M. (2014). It's not about seat time: Blending, flipping, and efficiency in active learning classrooms. Computers & Education, 78, 227-236. https://doi.org/10.1016/j.compedu.2014.06.006Berenguer Albaladejo, C. (2016). Acerca de la utilidad del aula invertida o flipped classroom. En M.T. Tortosa Ybáñez; S. Grau Company y J.D. Álvarez Teruel (coords.), XIV Jornades de xarxes d' investigació en docència universitária. Disponible en http://rua.ua.es/dspace/handle/10045/59358Bergmann, J.& Sams, A. (2014). Flipped learning: Maximizing face time. T+ D, 68(2), 28-31.Biggs, J. (2008). Calidad del aprendizaje universitario. Madrid: Narcea.Davies, R., Dean, D. y Ball, N. (2013). Flipping the classroom and instructional technology integration in a college-level information systems spreadsheet course. Educational Technology Research and Development, 61(4), 563-580. https://doi.org/10.1007/s11423-013-9305-6Grinsztajn F., Szteinberg R., Córdoba M. y Miguez M. (2015). Construcción de saber pedagógico y recursos educativos abiertos en la formación de profesionales para la docencia universitaria. REDU, Revista de Docencia Universitaria, 13, 275-299. https://doi.org/10.4995/redu.2015.5457Hernández Sampieri, R., Fernández Collado, C. y Baptista Lucio, P. (2010). Metodología de investigación. México: McGraw Hill.Kong, S. (2014). Developing information literacy and critical thinking skills through domain knowledge learning in digital classrooms: An experience of practicing flipped classroom strategy. Computers & Education, 78, 160-173. https://doi.org/10.1016/j.compedu.2014.05.009Martínez-Olvera, W.; Esquivel-Gámez, I.y Martínez, J. (2014). Aula invertida o modelo invertido de aprendizaje: Origen, sustento e implicaciones. En I. Esquivel (Coord.), Los Modelos Tecno-Educativos, revolucionando el aprendizaje del siglo XXI. Disponible en http://www.lulu.com/content/ebook/los-modelos-tecno-educativos-revolucionando-el-aprendizaje-del-sigloxxi/16266417.Mason, G., Shuman, T. y Cook, K. (2013). Comparing the effectiveness of an inverted classroom to a traditional classroom in an upper-division engineering course. Education, IEEE Transactions on, 56(4), 430-435. https://doi.org/10.1109/TE.2013.2249066Pierce, R. y Fox, J. (2012). Vodcasts and active-learning exercises in a "flipped classroom" model of a renal pharmacotherapy module. American Journal of Pharmaceutical Education, 76(10), 196. https://doi.org/10.5688/ajpe7610196Silva J. y Maturana, D. (2017). Una propuesta de modelo para introducir metodologías activas en educación superior. Innovación Educativa, 17(73), 117-132.Simón Llovet, J.; Ojando Pons, E.S.; Ávila Morena, X.; Miralpeix Bosch, A.; López Vicente, P. y Prats Fernández. M.Á. (2018). Reformulación de los roles del docente y del discente en la educación. El caso práctico del modelo de la Flipped Classroom en la universidad. Revista de Estudios y Experiencias en Educación, 2, 53-73. https://doi.org/10.21703/rexe.Especial2_201853733Sosa, M. J. y Palau, R. F. (2018). Flipped Classroom en la Formación Inicial del Profesorado: Perspectiva del alumnado. REDU. Revista de Docencia Universitaria, 16(2), 249-264. https://doi.org/10.4995/redu.2018.7911Tune, J., Sturek, M., y Basile, D. (2013). Flipped classroom model improves graduate student performance in cardiovascular, respiratory, and renal physiology. Advances in Physiology Education, 37(4), 316-320. https://doi.org/10.1152/advan.00091.201

Finite-Key Effects in Quantum Access Networks with Wireless Links

The finite-key effects in quantum access networks are studied. We consider a quantum-classical network where each user is equipped with a certain wavelength to exchange secure keys, using quantum key distribution techniques, and another one to exchange classical data. Users are connected to the central office via a passive optical network. The quantum users are connected to the fiber links via an indoor wireless channel. We investigate the regimes of operation within which a secure key can be exchanged in a reasonable amount of time. We find out that by properly designing the system, it is possible to run both quantum and classical systems at their full capacity

Wavelength assignment in quantum access networks with hybrid wireless-fiber links

We propose a low-complexity near-optimal wavelength allocation technique for quantum key distribution access networks that rely on wavelength division multiple access. Such networks would allow users to send quantum and classical signals simultaneously on the same optical fiber infrastructure. Users can be connected to the access network via optical wireless or wired links. We account for the background noise present in the environment, as well as the Raman noise generated by classical channels, and calculate the secret key generation rate for quantum channels in the finite-key setting. This allows us to examine the feasibility of such systems in realistic scenarios when the secret key exchange needs to be achieved in a limited time scale. Our numerical results show that, by proper choice of system parameters for this noisy system, it is possible to exchange a secret key in tens of seconds. Moreover, our proposed algorithm can enhance the key rate of quantum channels, especially in high-noise and/or high-loss regimes of operation