724 research outputs found

    Year 2020: A Snapshot of the Last Progress in Flexible Printed Gas Sensors

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    A review of recent advances in flexible printed gas sensors is presented. During the last years, flexible electronics has started to offer new opportunities in terms of sensors features and their possible application fields. The advent of this technology has made sensors low-cost, thin, with a large sensing area, lightweight, wearable, flexible, and transparent. Such new characteristics have led to the development of new gas sensor devices. The paper makes some statistical remarks about the research and market of the sensors and makes a shot of the printing technologies, the flexible organic substrates, the functional materials, and the target gases related to the specific application areas. The conclusion is a short notice on perspectives in the field

    Boltzmann-Gibbs thermal equilibrium distribution for classical systems and Newton law: A computational discussion

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    We implement a general numerical calculation that allows for a direct comparison between nonlinear Hamiltonian dynamics and the Boltzmann-Gibbs canonical distribution in Gibbs Γ\Gamma-space. Using paradigmatic first-neighbor models, namely, the inertial XY ferromagnet and the Fermi-Pasta-Ulam β\beta-model, we show that at intermediate energies the Boltzmann-Gibbs equilibrium distribution is a consequence of Newton second law (F=ma{\mathbf F}=m{\mathbf a}). At higher energies we discuss partial agreement between time and ensemble averages.Comment: New title, revision of the text. EPJ latex, 4 figure

    Field-Assisted and Thermionic Contributions to Conductance in SnO2 Thick-Films

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    A deep analysis of conductance in nanostructured SnO2 thick films has been performed. A model for field-assisted thermionic barrier crossing is being proposed to explain the film conductivity. Themodel has been applied to explain the behavior of resistance in vacuum of two sets of nanostructured thick-films with grains having two well-distinct characteristic radii (R = 25nm and R = 125 nm). In the first case the grain radius is shorter than the depletion region width, a limit at which overlapping of barriers takes place, and in the second case it is longer. The behavior of resistance in the presence of dry air has been explained through the mechanism of barrier modulation through gas chemisorption.Fil: Malagú, C.. Universita Di Ferrara; ItaliaFil: Carotta, M. Cristina. Universita Di Ferrara; ItaliaFil: Martinelli, Giuliano. Universita Di Ferrara; ItaliaFil: Ponce, Miguel Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Castro, Miriam Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Aldao, Celso Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

    Chemoresistive Gas Sensors for Sub-ppm Acetone Detection☆

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    New sensors for detecting acetone directly in the exhaled breath have been developed. Several metal oxide materials, ZnO in different nano-morphologies, WO3 pure and Zr-loaded and TixSn1-xO2 solid solutions, have been considered for comparing the functional properties of the corresponding thick films with respect to the target gas. ZnO nano-sheets and bipyramidal nano-aggregates exhibited the large responses towards acetone, however ZnO aggregates of nanocrystals, Zr-WO3 and TixSn1-xO2 showed better performances as regards the influence of humidity on the acetone response

    Pax5 maintains cellular identity by repressing gene expression throughout B cell differentiation.

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    The transcription factor Pax5 is required for many aspects of B-lymphopoiesis including lineage commitment, immunoglobulin rearrangement, pre-BCR signalling and mature B cell survival. Pax5 regulates B cell lineage commitment by concurrently activating B cell specific gene expression as well as suppressing the expression of genes associated with non-B cell fates. The identity of the molecular targets of Pax5-mediated gene repression is the subject of much current interest. Recent studies have documented the essential nature of the Pax5 repression of the stem cell transcriptional program, as well as the silencing of lineage inappropriate gene expression, for B cell development. Surprisingly the repression of genes by Pax5 continues throughout lymphopoiesis, with the loss of Pax5 in mature B cell resulting in the reactivation of the same Pax5 targets during plasma cell differentiation. These recent insights into the mechanism of action of Pax5 in controlling B cell identity will be discussed

    (Ti,Sn) solid solution-based gas sensors for new monitoring of hydraulic oil degradation

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    The proper operation of a fluid power system in terms of efficiency and reliability is directly related to the fluid state; therefore, the monitoring of fluid ageing in real time is fundamental to prevent machine failures. For this aim, an innovative methodology based on fluid vapor analysis through metal oxide (shortened: MOX) gas sensors has been developed. Two apparatuses were designed and realized: (i) a dedicated test bench to fast-age the fluid under controlled conditions; (ii) a laboratory MOX sensor system to test the headspace of the aged fluid samples. To prepare the set of MOX gas sensors suitable to detect the analytes’ concentrations in the fluid headspace, different functional materials were synthesized in the form of nanopowders, characterizing them by electron microscopy and X-ray diffraction. The powders were deposited through screen-printing technology, realizing thick-film gas sensors on which dynamical responses in the presence of the fluid headspace were obtained. It resulted that gas sensors based on solid solution TixSn1–xO2 with x = 0.9 and 0.5 offered the best responses toward the fluid headspace with lower response and recovery times. Furthermore, a decrease in the responses (for all sensors) with fluid ageing was observed

    Educação permanente em saúde: uma estratégia de gestão para pensar, refletir e construir práticas educativas e processos de trabalhos

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    The present work reports the experience of the local authority of Embu, in the State of São Paulo, in the implementation of the National Policy of Permanent Health Education (PHE) proposed by the Ministry of Health. This strategy was adopted by the municipal management with the objective of identifying and defining educational actions that qualify health care and management through the education and development of the workers of the sector. PHE works with tools that aim at the critical reflection on the daily practice of the health services, being an educational process applied to work that enables changes in the relations, processes, healthcare practices and persons. Other potentialities of this strategy are: strengthening of social control; re-politicization of the Brazilian public health system (SUS); stimulation to the leading role of users and workers in the health and disease process; and production of a positive impact on the individual and collective health of the population.Este trabalho relata a experiência de implantação da Política Nacional de Educação Permanente em Saúde (EPS), proposta pelo Ministério da Saúde (Portaria 198 de fevereiro de 2004) no município de Embu, Estado de São Paulo, Essa implantação foi adotada pela gestão municipal com o objetivo de identificar e definir ações educativas que qualifiquem a atenção e a gestão em saúde através da formação e do desenvolvimento dos trabalhadores do setor. A EPS trabalha com ferramentas que buscam a reflexão crítica sobre a prática cotidiana dos serviços de saúde, sendo, por si só, um processo educativo aplicado ao trabalho que possibilita mudanças nas relações, nos processos, nos atos de saúde e nas pessoas. Outras potencialidades dessa estratégia são: fortalecimento do controle social; repolitização do Sistema Único de Saúde (SUS); incentivo ao protagonismo de usuários e trabalhadores no processo saúde e doença e a produção de um impacto positivo sobre a saúde individual e coletiva da população

    Flint’s Children: Narratives on Hope

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    Hope plays an important role in resiliency, well-being, and buffering against adversity. To explore children’s experiences with hope while developing in low-income communities, we conducted interviews with twenty-one children residing in Flint, Michigan, ages 9-12 years. Research questions focused on the specific hopes children have, the importance they ascribe to different hopes, and their experiences of feeling hopeful or less hopeful about desired outcomes. Children expressed interrelated hopes across multiple social-ecological domains, including hopes for themselves, hopes for their interpersonal relationships, and hopes for the community. Children placed particular importance on their hopes of helping others, which included providing for their families and aiding others in the community. Children, however, expressed uncertainty regarding their hopes related to career aspirations, academic achievement, financial stability, and obtaining basic needs. Our findings expand upon what is known about children’s internal dialogues with feeling hopeful or less hopeful about desired outcomes in low-income communities. These findings can enhance community and school-based programming so they further align with the specific hopes that children have, and attune to areas in which children in impoverished communities are most in need of hope-engendering strategies

    Growth of ZnO tetrapods for gas sensor application

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    Zinc Oxide (ZnO) nanostructures have been obtained by vapour phase growth. Tetrapods have been grown in a reproducible way and separated from the other possible ZnO nano-morphologies, by the optimization of growth parameters. The further deposition of these nanostructures on an alumina substrate with contacts and heater, allowed us to test the gas sensing properties of the obtained ZnO tetrapods with different gases
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