757 research outputs found

    Electrochemical study on an activated carbon cloth modified by cyclic voltammetry with polypyrrole/anthraquinone sulfonate and reduced graphene oxide as electrode for energy storage

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    [EN] This work describes a two-step procedure for the electrochemical coating of reduced graphene oxide (RGO) and polypyrrole anthraquinone sulfonate (PPyAQS) onto an activated carbon cloth (ACC) by cyclic voltammetry (CV). The textile samples were characterized by CV, electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge measurements using a sandwich-type (electrode/separator/electrode) cell designed to operate in three or two-electrode configurations. The presence of RGO onto the ACC surface optimized the electrosynthesis of PPyAQS and reinforced the stability of the polymer with the number of charge/discharge cycles. A retention capacity of 90% after 100 charge-discharge cycles together with an energy density of 7.8¿×¿10¿4¿W¿h¿cm¿2 at a power density of 1.8¿×¿10¿3¿W¿cm¿2 were obtained for the ACC/RGO/PPyAQS sample. The analyses by field emission scanning electron microscopy (FESEM) showed the RGO veils-like and PPyAQS glomerular structures covering the ACC-fibers. The Fourier transform infrared spectroscopy (FTIR) analyses not only detected the presence of PPy and AQS, but also, the changes in the molecular structure of PPyAQS, depending on its oxidation state, as consequence of the redox reactions occurred in the charge/discharge processes in the two-electrode cell.The authors wish to acknowledge to Chemviron Carbon who kindly donated the ZORFLEX® activated carbon fabric. The authors wish to thank the Spanish Agencia Estatal de Investigación de Economía (AEI) and European Union (FEDER funds) for the financial support (contract MAT2016-77742-C2-1-P). Tim Vickers is gratefully acknowledged for help with the English revision. Electron Microscopy Service of the UPV (Universitat Politècnica de València) is gratefully acknowledged for help with FESEM characterization.Fernández Sáez, J.; Bonastre Cano, JA.; Molina Puerto, J.; Cases, F. (2018). Electrochemical study on an activated carbon cloth modified by cyclic voltammetry with polypyrrole/anthraquinone sulfonate and reduced graphene oxide as electrode for energy storage. European Polymer Journal. 103:179-186. https://doi.org/10.1016/j.eurpolymj.2018.04.018S17918610

    On-site forest fire smoke detection by low-power autonomous vision sensor

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    Early detection plays a crucial role to prevent forest fires from spreading. Wireless vision sensor networks deployed throughout high-risk areas can perform fine-grained surveillance and thereby very early detection and precise location of forest fires. One of the fundamental requirements that need to be met at the network nodes is reliable low-power on-site image processing. It greatly simplifies the communication infrastructure of the network as only alarm signals instead of complete images are transmitted, anticipating thus a very competitive cost. As a first approximation to fulfill such a requirement, this paper reports the results achieved from field tests carried out in collaboration with the Andalusian Fire-Fighting Service (INFOCA). Two controlled burns of forest debris were realized (www.youtube.com/user/vmoteProject). Smoke was successfully detected on-site by the EyeRISTM v1.2, a general-purpose autonomous vision system, built by AnaFocus Ltd., in which a vision algorithm was programmed. No false alarm was triggered despite the significant motion other than smoke present in the scene. Finally, as a further step, we describe the preliminary laboratory results obtained from a prototype vision chip which implements, at very low energy cost, some image processing primitives oriented to environmental monitoring.Ministerio de Ciencia e Innovación 2006-TIC-2352, TEC2009-1181

    Comportamiento de 13 modelos de cinta de riego en condiciones de invernadero con agua regenerada

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    El objetivo de este trabajo ha sido seleccionar modelos de cinta de riego con una mejor adaptación a las condiciones de invernadero y riego con aguas regeneradas. Se ha evaluado el comportamiento de 13 modelos comerciales de cintas de riego seleccionados de entre los más utilizados en los cultivos hortícolas al aire libre, y aquellos que, las empresas instaladoras y fabricantes consideren que, por sus características, pueden tener un buen comportamiento con este tipo de aguas. En la evaluación de campo todos los emisores han presentado valores de uniformidad elevados al comienzo de la campaña de riego. Cinco de las cintas se clasifican como excelentes y el resto como buenas. Al finalizar las 114 horas de trabajo decae sustancialmente la uniformidad. El comportamiento tras la finalización de la primera campaña de riego se puede considerar equiparable al obtenido en un estudio previo con una selección de 20 emisores en ramal convencional y este tipo de aguas. Se puede concluir que las cintas de riego localizado pueden ser una alternativa a los ramales de riego convencionales cuando se riega con aguas residuales urbanas regeneradas, siempre que se elija un material de una mínima calidad y el ratio de sustitución garantice una uniformidad alta

    Estados de condición del sitio pastizal de gramíneas bajas de planicie presentes en el departamento Loventué La Pampa

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    It has been evaluating range condition in twenty areas of shortgrasslands in Loventué - La Pampa. The state Condition's identification was realized with the standing - crop's dates. Frequency, density, cover and height of principal’s species were taken. The following indices were used to classified the grassland's Condition: Very Good; Good, Fair, Poor and Very Poor.Se evaluó la condición de pastura en 20 áreas de pastizal de planicie en el Departamento Loventué, La Pampa. La identificación del estado de condición se realizó en función del peso de las especies por unidad de muestreo. Se hicieron además determinaciones de frecuencia, densidad, cobertura y altura de las especies más importantes. Para la determinación de la condición de las áreas, fueron usados los siguientes índices: Muy buena. Buena, Regular, Mala y Muy Mala

    Geometrically induced modification of surface plasmons in the optical and telecom regimes

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    We demonstrate that the introduction of a subwavelength periodic modulation into a metallic structure strongly modifies the guiding characteristics of the surface plasmon modes supported by the system. Moreover, it is also shown how a new type of a tightly confined surface plasmon polariton mode can be created by just milling a periodic corrugation into a metallic ridge placed on top of a metal surface

    On-site forest fire smoke detection by low-power autonomous vision sensor

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    Trabajo presentado a la VI International Conference on Forest Fire Research celebrada en Coimbra (Portugal) del 15 al 18 de noviembre de 2010.Early detection plays a crucial role to prevent forest fires from spreading. Wireless vision sensor networks deployed throughout high-risk areas can perform fine-grained surveillance and thereby very early detection and precise location of forest fires. One of the fundamental requirements that need to be met at the network nodes is reliable low-power on-site image processing. It greatly simplifies the communication infrastructure of the network as only alarm signals instead of complete images are transmitted, anticipating thus a very competitive cost. As a first approximation to fulfill such a requirement, this paper reports the results achieved from field tests carried out in collaboration with the Andalusian Fire-Fighting Service (INFOCA). Two controlled burns of forest debris were realized (www.youtube.com/user/vmoteProject). Smoke was successfully detected on-site by the EyeRISTM v1.2, a general-purpose autonomous vision system, built by AnaFocus Ltd., in which a vision algorithm was programmed. No false alarm was triggered despite the significant motion other than smoke present in the scene. Finally, as a further step, we describe the preliminary laboratory results obtained from a prototype vision chip which implements, at very low energy cost, some image processing primitives oriented to environmental monitoring.This work is funded by CICE/JA and MICINN (Spain) through projects 2006-TIC-2352 and TEC2009-11812 respectively.Peer Reviewe

    Fitomasa disponible en un pastizal de Pappophorum caespitosum en el sudeste de la Pampa -Período 1984-1985

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    Standig crop of Pappophorum caespitosum "pasto blanco" grassland was determined in the southeastern of La Pampa Province, Dpto. Caleu Caleu, Ea. Los Guadales. Lat. 38°13'S - Long. 64°18' W. At the end of autumn (june) the grassland reached 315 gMS/m2. Pappophorum caespitosum the principal specie totalized 248,6 gMS/m2. In spring (november) Medicago minima "Trebol de carretilla", Erodium cicutarium "alfilerillo" y Pelletiera serpyllifolia three annual species gave only 61.4 gMS/m2. The vegetation cover was middle in the grassland during all the year-, "Pasto blanco", Setaria pampeana "cola de zorro" y Stipa ambigua "paja vizcachera" had 100 % of frecuencySe determinó la fitomasa aérea mensual de un pastizal de Pappophorum caespitosum Fries "pasto blanco" en el Sur este de La Pampa, Ea. Los Guadales, Dpto. Caleu Caleu Lat. 38°13' S - Long. 64°18' W. El pastizal alcanzo a fines de otoño 315 gMS/m2. Pappophorum caespitosum, la especie dominante, totalizó 248,6 gMS/m2. Medicago minima "trébol decarretilla", Erodium cicutarium "alfilerillo" y Pelletiera serpyllifolia brindaron solo 61,4 gMS/m2 en primavera (noviembre). La cobertura de la vegetación fué mediana a lo largo de todo el año. "Pasto blanco" tuvo el 100% de frecuencia, también lo alcanzaron Setaria pampeana "cola de zorro" y Stipa ambigua "paja vizcachera"

    Europium and Terbium doped apatite obtained by hydrothermal transformation of biogenic calcium carbonate from oyster shells

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    Póster presentado en The International Conference on Crystal Growth and Epitaxy-ICCGE-20, Naples (Italy), 30-july 4 august 2023Seashell wastes from aquaculture and canning industries represent an important environmental issue nowadays [1]. Shells are made of calcium carbonate (CaCO3) with a low content of proteins and polysaccharides (1-5 wt.%). The valorization of this waste by using it as a raw material for the production of calcium phosphates may have a positive impact both environmental and economic, thus contributing to the sustainability of this important sector. In some biomedical industries, there is a growing demand for calcium phosphate (apatite) crystals including nanosized, micron-sized, and larger sizes. This work is devoted to producing functional apatite nanocrystals, eg. doped with luminescent lanthanide (Ln3+) ions [2,3], using oyster shells (Mg-calcite, 5 wt.% Mg) from the species Crassostrea gigas as a Ca source. Experiments were performed by a one-pot hydrothermal method using KH2PO4 as a P reagent, a P/CaCO3 ratio of 0.6 (stoichiometric respect to hydroxyapatite), and either Eu3+ or Tb3+ (10and 20 mM). Characterization by XRD, FTIR, Raman, and ICP revealed the full transformation of biogenic CaCO3 particles into doped apatite. It was obtained at 160 ºC with (Ca+Ln)/P ratios 1.72 and 1.68 when adding Eu3+ and Tb3+ (10 mM) and 1.88 and 1.99 when the lanthanide concentration in the solution increased to 20 mM. In both cases, nanocrystals displayed needleor plate-like morphologies and polydisperse size distribution. Luminescence characterization of the nanoparticles showed different luminescence spectra depending on the doping ion. They displayed excitation and emission wavelengths of 395nm and 616 nm for the Eu3+-, and 372 and 543 nm for the Tb3+-doped samples. The relative luminescence intensities correlated well with their Ln3+ content while luminescence lifetimes (up to 1600 ¿s) were higher for Tb3+-doped apatites. Overall, the nanoparticles showed notable luminescent behavior and could find application as luminescent probes for bioimaging or nanophosphors for the electronic industry. Acknowledgements: Grant ref. PCI2020-112108 is funded by MCIN/AEI/10.13039/501100011033 (Spain) and the European Union "NextGenerationEU"/PRTR". PCI2020-112108 is part of the project CASEAWA of ERA-NET Cofund BlueBio H2020.Grant ref. PCI2020-112108 is funded by MCIN/AEI/10.13039/501100011033 (Spain) and the European Union "NextGenerationEU"/PRTR". PCI2020-112108 is part of the project CASEAWA of ERA-NET Cofund BlueBio H202

    Comparación de las medidas de humedad en suelo enarenado con diferentes sensores

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    Poster[ES] Una opción ambiciosa para gestionar el riego es emplear sensores como activadores del riego. El éxito de la automatización del riego empleando sensores de humedad de suelo depende, entre otros factores, de la adaptación del sensor a las características del suelo. El objetivo de este trabajo es evaluar el comportamiento de tres equipos de medida de humedad en un suelo enarenado característico de los cultivos hortícolas bajo abrigo desarrollados en el Sureste de España.El trabajo ha sido cofinanciado por Fondos Europeos (FSE y FEDER) y la Consejería de Agricultura y Pesca (IFAPA Junta de Andalucía) mediante el Proyecto Transforma Conecta SAR (PP.TRA.TRA201300.10).Baeza Cano, R.; Contreras París, J.; Alonso López, F.; Cánovas Fernández, G.; López Segura, J. (2014). Comparación de las medidas de humedad en suelo enarenado con diferentes sensores. En CONFERENCIA INTERNACIONAL INFOACES. UN SISTEMA DE INFORMACIÓN PARA LAS UNIVERSIDADES LATINOAMERICANAS. LIBRO DE ACTAS. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/94683OC
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