3,054 research outputs found

    Manipulation and Generation of Supercurrent in Out-of-Equilibrium Josephson Tunnel Nanojunctions

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    We demonstrate experimentally manipulation of supercurrent in Al-AlO_x-Ti Josephson tunnel junctions by injecting quasiparticles in a Ti island from two additional tunnel-coupled Al superconducting reservoirs. Both supercurrent enhancement and quenching with respect to equilibrium are achieved. We demonstrate cooling of the Ti line by quasiparticle injection from the normal state deep into the superconducting phase. A model based on heat transport and non-monotonic current-voltage characteristic of a Josephson junction satisfactorily accounts for our findings.Comment: 4 pages, 4 colour figures, published versio

    Localization lengths of ultrathin disordered gold and silver nanowires

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    The localization lengths of ultrathin disordered Au and Ag nanowires are estimated by calculating the wire conductances as functions of wire lengths. We study Ag and Au monoatomic linear chains, and thicker Ag wires with very small cross sections. For the monoatomic chains we consider two types of disorder: bounded random fluctuations of the interatomic distances, and the presence of random substitutional impurities. The effect of impurity atoms on the nanowire conductance is much stronger. Our results show that electrical transport in ultrathin disordered wires may occur in the strong localization regime, and with relatively small amounts of disorder the localization lengths may be rather small. The localization length dependence on wire thickness is investigated for Ag nanowires with different impurity concentrations.Comment: 6 pages, postscript figures included, submitted to PR

    Validando buenas prácticas en la docencia de Trabajo Social: en el camino de la innovación didáctica

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    Durante el curso pasado, la red REDITS avanzó en la identificación de diversas estrategias para mejorar la adquisición de competencias que quedaron volcadas en la memoria del proyecto desarrollado. Siguiendo con el trabajo iniciado, la red se propuso una labor de transferencia de conocimientos comparativos en prácticas docentes innovadoras para formación en competencias entre cuatro universidades españolas y una italiana. Este objetivo supone que una vez realizada una primera identificación de posibles buenas prácticas, debe realizarse su validación antes de replicarla. Una vez concluido ese trabajo se las incorporará a una Guía de buenas prácticas en didáctica de TS. Asimismo, del proceso de validación surgen debates y propuestas de análisis para supervisión y sistematización de la práctica en TS. Para este curso se seleccionaron dos buenas prácticas, la supervisión educativa y la realización de una experiencia de elaboración y edición de una revista desde criterios científicos. En la primera práctica se trabajó desde la evaluación mediante la aplicación de un cuestionario aplicado a diversas universidades con experiencia en este tipo de actividad y en el segundo caso al tratarse de una experiencia más novedosa se realizó su sistematización, recogiendo paralelamente el nivel de satisfacción del estudiantado con la práctica

    Diagnosis of right bundle branch block: a concordance study

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    Bundle branch block; ConcordanceBloqueig de branca; ConcordançaBloqueo de rama; ConcordanciaBACKGROUND: Right bundle branch block is one of the most common electrocardiographic abnormalities. Most cases of right bundle branch block are detected in asymptomatic patients in primary care, so a correct interpretation of electrocardiograms (ECGs) at this level is necessary. The objective of this research is to determine the degree of concordance in the diagnosis of incomplete and complete right bundle branch block between four primary care researchers and a cardiologist. METHODS: The research design is a retrospective cohort study of patients over 18 years of ages of patients over 18 years of ages who underwent an ECG for any reason and were diagnosed with right bundle branch block by their physician. The physicians participating, 4 primary care researchers and a cardiologist were specialized in interpreting electrocardiographic records. The diagnosis of incomplete and complete right bundle branch block was recorded and other secondary variables were analysed. In case of diagnostic discordance between the researchers, the ECGs were reviewed by an expert cardiologist, who interpreted them, established the diagnosis and analysed the possible causes for the discrepancy. RESULTS: We studied 160 patients diagnosed with right bundle branch block by their general practise. The patients had a mean age of 64.8 years and 54% of them were men. The concordance in the diagnosis of incomplete right bundle branch block showed a Fleiss' kappa index (k) of 0.71 among the five researchers and of 0.85 among only the primary care researchers. The k for complete right bundle branch block was 0.93 among the five researchers and 0.96 among only the primary care researchers. CONCLUSION: The interobserver agreement in the diagnosis of right bundle branch block performed by physicians specialized in ECG interpretation (primary care physicians and a cardiologist) was very good. The variability was greater for the diagnosis of incomplete right bundle branch block

    Gemma Avenoza Vera, passion for manuscript study

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    Free-electron Model for Mesoscopic Force Fluctuations in Nanowires

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    When two metal electrodes are separated, a nanometer sized wire (nanowire) is formed just before the contact breaks. The electrical conduction measured during this retraction process shows signs of quantized conductance in units of G_0=2e^2/h. Recent experiments show that the force acting on the wire during separation fluctuates, which has been interpreted as being due to atomic rearrangements. In this report we use a simple free electron model, for two simple geometries, and show that the electronic contribution to the force fluctuations is comparable to the experimentally found values, about 2 nN.Comment: 4 pages, 3 figures, reference correcte

    Supervisión en Trabajo Social, clave para la construcción del "ethos" profesional

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    La supervisión constituye en la didáctica del Trabajo Social, uno de los espacios históricos, en cuanto a que es inherente al origen de la profesión, a la vez que, un ámbito de permanente innovación porque establece la relación entre la teoría y la práctica. Esta comunicación es parte de los resultados del trabajo de investigación que se encuentra desarrollando la Red Interuniversitaria sobre Didáctica en Trabajo Social (REDITS). Se ha revisado la literatura especializada sobre competencias en Trabajo Social, prácticas y supervisión, con el fin de guiar la investigación sobre las prácticas externas con el alumnado de las universidades participantes en la red. Asimismo se trabajó con alumnado de último curso en la elaboración de una DAFO que identificara las debilidades, fortalezas, oportunidades y amenazas, percibidas en las prácticas externas. Los objetivos planteados son en primer lugar demostrar la relación de las prácticas externas con la consolidación de los conocimientos teóricos a través de la intervención social y en segundo lugar fundamentar la necesidad de la supervisión como un elemento clave para la construcción del “ethos” y la deontología profesional

    Fabrication and performance of low-fouling UF membranes for 2 the treatment of Isolated Soy Protein solutions

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    [EN] Consumers are becoming more conscious about the need to include functional and nutritional foods in their diet. This has increased the demand for food extracts rich in proteins and peptides with physiological effects that are used within the food and pharmaceutical industries. Among these protein extracts, soy protein and its derivatives are highlighted. Isolated soy protein (ISP) presents a protein content of at least 90%. Wastewaters generated during the production process contain small proteins (8-50 kDa), and it would be desirable to find a recovery treatment for these compounds. Ultrafiltration membranes (UF) are used for the fractionation and concentration of protein solutions. By the appropriate selection of the membrane pore size, larger soy proteins are retained and concentrated while carbohydrates and minerals are mostly recovered in the permeate. The accumulation and concentration of macromolecules in the proximity of the membrane surface generates one of the most important limitations inherent to the membrane technologies. In this work, three UF membranes based on polyethersulfone (PES) were fabricated. In two of them, polyethylene glycol (PEG) was added in their formulation to be used as a fouling prevention. The membrane fouling was evaluated by the study of flux decline models based on Hermia's mechanisms.The Universitat Politecnica de Valencia (Spain), through the project 2623 (PAID-05-10), funded this research.Garcia-Castello, EM.; Rodríguez López, AD.; Barredo Damas, S.; Iborra Clar, A.; Pascual-Garrido, J.; Iborra-Clar, MI. (2021). Fabrication and performance of low-fouling UF membranes for 2 the treatment of Isolated Soy Protein solutions. Sustainability. 13(24):1-16. https://doi.org/10.3390/su132413682S116132

    liteITD a MATLAB Graphical User Interface (GUI) program for topology design of continuum structures

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    Over the past few decades, topology optimization has emerged as a powerful and useful tool for the design of structures, also exploiting the ever growing computational speed and power. The design process has also been affected by computers which changed the concept of form into the concept of formation and the emergence of digital design. Topology optimization can modify existing designs, incorporate explicit features into a design and generate completely new designs. This paper will show how topology optimization can be used as a digital tool. The liteITD (lite version of Isolines Topology Design) software package will be described with the purpose of providing a tool for topology design. The liteITD program solves the topology optimization of two-dimensional continuum structures using von Mises stress isolines under single or multiple loading conditions, with different material properties in tension and compression, and multiple materials. The liteITD program is fully implemented in the MATrix LABoratory (MATLAB) software environment of MathWorks under Windows operating system. GUIDE (Graphical User Interface Development Environment) was used to create a friendly Graphical User Interface (GUI). The usage of this application is directed to students mainly (educational purposes), although also to designers and engineers with experience. The liteITD program can be downloaded and used for free from the website: http://www.upct.es/goe/software/liteITD.php
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