94 research outputs found

    Duplex stainless steels for thermal energy storage: characterization of oxide scales formed in carbonate salts at 500 °C

    Get PDF
    Next generation concentrated solar power (CSP) plants promise a higher operating temperature and better efficiency. However, new issues related to the corrosion against protection of the construction alloys need to be solved. In this work, two different duplex stainless steels grades, namely 2205 (DS2205) and 2507 (DS2507), were evaluated for their compatibility with the eutectic molten salt mixture of Li2CO3-K2CO3-Na2CO3 at 500 °C in air for thermal energy storage applications. Corrosion tests combined with complementary microscopy, microanalysis and mechanical techniques were employed to study the oxide scales formed on the surface of the duplex steels. The corrosion tests evidenced that the attack morphology in both duplex steels was a uniform oxidative process without localized corrosion. DS2507 presented a better corrosion resistance than DS2205, due to the formation of thinner, compact and continuous oxide layers with higher compositional content in Cr, Ni and Mo than DS2205. The oxide scales of DS2507 showed more remarkable mechanical integrity and adhesion to the metallic substrate.Postprint (published version

    Impact of previous macrolide use on invasive pneumococcal disease due to erythromycin-resistant serotypes in adults over 59 years of age

    Get PDF
    The major goals of the study were to describe the invasive pneumococcal disease (IPD) cases due to erythromycin-resistant serotypes and to evaluate the association between these cases and recent macrolide use in individuals aged over 59 years. We selected cases of IPD reported between 2007 and 2016 in persons aged over 59 years living in the Community of Madrid (CM). We followed the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The explanatory variables (age, sex, year of onset of symptoms, clinical presentation, serotypes, vaccination status) were taken from the Mandatory Notification System for Infectious Diseases System and from the Vaccination Information System. The cases were classified as either included in the 13-valent pneumococcal conjugate vaccine (PCV13) or not (nonPCV13). Associations between cases due to erythromycin-resistant serotypes and previous macrolide use (total, long and short-term) were adjusted with a logistic regression multivariate analysis. A total of 1,831 cases were identified, of whom 408 were erythromycin-resistant serotypes. PCV13 cases were associated with previous macrolide use (OR: 5.07), particularly long-acting types (OR: 8.61). NonPCV13 cases were associated with the use of total macrolides (OR: 3.48) and long-acting macrolides (OR: 4.26) suggesting that PCV13 did not reduce the IPD cases in patients with previous use of macrolides. Our results confirmed that previous macrolide consumption was associated with the presence of IPD due to erythromycin-resistant serotypes. The risk was higher with the use of long-term macrolides.S

    Corrosion evaluation of austenitic and duplex stainless steels in molten carbonate salts at 600 °C for thermal energy storage

    Get PDF
    Next-generation concentrated solar power (CSP) plants are required to operate at temperatures as high as possible to reach a better energy efficiency. This means significant challenges for the construction materials in terms of corrosion resistance, among others. In the present work, the corrosion behavior in a molten eutectic ternary Li2CO3-Na2CO3-K2CO3 mixture at 600 °C was studied for three stainless steels: an austenitic grade AISI 301LN (SS301) and two duplex grades, namely 2205 (DS2205) and 2507 (DS2507). Corrosion tests combined with complementary microscopy, microanalysis and mechanical characterization techniques were employed to determine the corrosion kinetics of the steels and the oxide scales formed on the surface. The results showed that all three materials exhibited a corrosion kinetics close to a parabolic law, and their corrosion rates increased in the following order: DS2507 < SS301 < DS2205. The analyses of the oxide scales evidenced an arranged multilayer system with LiFeO2, LiCrO2, FeCr2O4 and NiO as the main compounds. While the Ni-rich inner layer of the scales presented a good adhesion to the metallic substrate, the outer layer formed by LiFeO2 exhibited a higher concentration of porosity and voids. Both the Cr and Ni contents at the inner layer and the defects at the outer layer were crucial for the corrosion resistance for each steel. Among the studied materials, super duplex stainless steel 2507 is found to be the most promising alternative for thermal energy storage of those structural components for CSP plants.Peer ReviewedPostprint (published version

    El Sinemuriense superior: cronozonas Obtusum y Oxynotum en Asturias,España. Ammonoideos y correlación con otras cuencas del oeste de Europa

    Get PDF
    Se estudia la cronoestratigrafía, biosedimentación y, en particular, la sucesión de los ammonoideos que, con un registro relativamente pobre, se encuentra en varias secciones del Sinemuriense superior (cronozonas Obtusum y Oxynotum) de la costa de Asturias, entre la Playa de Peñarrubia (Gijón) y la Playa de Vega (Ribadesella). Si se exceptúa el límite inferior de la cronozona Obtusum, todas las unidades cronoestratigráficas han podido ser caracterizadas con bastante precisión. En la cronozona Obtusum (subcronozonas Obtusum y Stellare) se suceden en el tiempo siete especies de Asteroceras (A. aff. confusum-A. confusum-A. obtusum-A. cf. margaritoides-A. stellare-A. blakei) y Aegasteroceras (A. sagittarium), que de forma puntual pueden estar asociadas a escasos Epophioceras, Xipheroceras, Promicroceras y Cymbites. La subcronozona Denotatus se caracteriza por la sucesión de tres especies de Eparietites (E. undaries-E. impendens-E. glaber) asociadas a raros Promicroceras. En la cronozona Oxynotum se registran Palaeoechioceras, Gagaticeras (G. cf. exortum-G. gagateum) y Oxynoticeras (O. simpsoni) en la subcronozona Simpsoni y Oxynoticeras (O. oxynotum) asociado a Cheltonia (C. accipitris) en la subcronozona Oxynotum. En la parte media y superior de esta subcronozona, se registran asimismo escasos Paroxynoticeras y escasos Bifericeras y Gleviceras. En el aspecto paleobiogeográfico, la sucesión obtenida es típica de la Provincia del NO Europeo con la inclusión de algunos elementos más propios de la Provincia Mediterránea en la parte media y superior de la cronozona Obtusum (Asteroceras cf. suevicum, E. glaber) y en la parte media de la cronozona Oxynotum (Paroxynoticeras salisburgense)

    Wireless sensor networks for monitoring HVAC systems

    Get PDF
    The current paper exposes a technological solution for monitoring heating, ventilating and air conditioning systems, aka HVAC. For this, it is used wireless sensors to build a network that will monitor atmospheric variables such as temperature and relativity humidity, in places that have installed this type of systems.El presente artículo expone una solución tecnológica para monitorizar sistemas de aire acondicionado, ventilación y calefacción, conocido como HVAC por sus siglas en inglés; en el que se propone el uso de sensores inalámbricos para construir una red que monitoriza variables atmosféricas como la temperatura y humedad relativa, en los recintos que cuenten con éstos sistemas

    Stratigraphy and Biochronostratigraphy of the Lower Pliensbachian (Jurassic) from the Asturian basin (Northern Spain)

    Get PDF
    A stratigraphic study of the carbonate deposits from the interval between the uppermost Sinemurian and the base of the Upper Pliensbachian is presented herein. For this purpose, four expanded sections of the Asturian Basin, in Northern Spain, were sampled. The sections are located between Rodiles E section (Villaviciosa municipality) and Playa de Vega section (Ribadesella municipality). The ammonites recorded in over 100 successive levels of this sector enabled the substantial improvement of the biochronostratigraphic scale of reference; making it comparable with those defined for other basins of the Iberian Peninsula and other areas of the western Tethys. The lower boundary of the Pliensbachian is indicated by the first appearance of Gemmellaroceras aff. aenigmaticum (Gemmellaro) below the first appearance of the genus Apoderoceras. The upper boundary is defined by the first record of the Protogrammoceras. (Matteiceras) subgenus which in some levels is associated with Amaltheus stokesi (Sowerby). The boundaries between the zones and subzones were able to be established accurately in most cases. The ammonite assemblages are similar to those established for the NW European Province. Some intervals, however, include species typical of the Mediterranean Province. Among these, the Taylori Subchronozone (Gemmellaroceras) and the transition between the Jamesoni Subchronozone and the Valdani Subchronozone (Tropidoceras) can be highlighted. Additionally, taking into consideration the succession between of ammonite genera and species, 27 horizons were identified, 24 of which correspond to the Lower Pliensbachian, and the other 3 to the uppermost Sinemurian and the lowermost part of the Upper Pliensbachian. Moreover, the identification of 3 of the Lower Pliensbachian horizons were based upon the evolution of the Mediterranean Tropidoceras

    II Jornadas de la Sociedad Española para la Conservación y Estudio de Los Mamíferos (SECEM) Soria 7-9 diciembre 1995

    Get PDF
    Seguimiento de una reintroducción de corzo (Capreolus capreolus) en ambiente mediterráneo. Dispersión y área de campeoModelos de distribución de los insectívoros ern la Península IbéricaDieta anual del zorro, Vulpes vulpes, en dos hábitats del Parque Nacional de DoñanaDesarrollo juvenil del cráneo en las poblaciones ibéricas de gato montés, Felis silvestris Schreber, 1777Presencia y expansión del visón americano (Mustela vison) en las provincias de Teruel y Castellón (Este de España).Preferencias de hábitat invernal de la musaraña común (Crocidura russula) en un encinar fragmentado de la submeseta norteUso de cámaras automáticas para la recogida de información faunística.Dieta del lobo en dos zonas de Asturias (España) que difieren en carga ganadera.Consumo de frutos y dispersión de semillas de serbal (Sorbus aucuparia L.) por zorros y martas en la cordillera Cantábrica occidentalEvaluación de espermatozoides obtenidos postmorten en el ciervo.Frecuencia de aparición de diferentes restos de conejo en excrementos de lince y zorroAtlas preliminar de los mamíferos de Soria (España)Censo y distribución de la marmota alpina (Marmota marmota) en Navarra.Trampeo fotográfico del género Martes en el Parque Nacional de Aigüestortes i Estany de Sant Maurici (Lleida)Peer reviewe

    Twenty years of ground-based NDACC FTIR spectrometry at Izaña Observatory-overview and long-term comparison to other techniques

    Get PDF
    High-resolution Fourier transform infrared (FTIR) solar observations are particularly relevant for climate studies, as they allow atmospheric gaseous composition and multiple climate processes to be monitored in detail. In this context, the present paper provides an overview of 20 years of FTIR measurements taken in the framework of the NDACC (Network for the Detection of Atmospheric Composition Change) from 1999 to 2018 at the subtropical Izaña Observatory (IZO, Spain). Firstly, long-term instrumental performance is comprehensively assessed, corroborating the temporal stability and reliable instrumental characterization of the two FTIR spectrometers installed at IZO since 1999. Then, the time series of all trace gases contributing to NDACC at IZO are presented (i.e. C2_{2}H6_{6}, CH4_{4}, ClONO2_{2}, CO, HCl, HCN, H2_{2}CO, HF, HNO3_{3}, N2_{2}O, NO2_{2}, NO, O3_{3}, carbonyl sulfide (OCS), and water vapour isotopologues H2_{2}16^{16}O, H2_{2}18^{18}O, and HD16^{16}O), reviewing the major accomplishments drawn from these observations. In order to examine the quality and long-term consistency of the IZO FTIR observations, a comparison of those NDACC products for which other high-quality measurement techniques are available at IZO has been performed (i.e. CH4_{4}, CO, H2_{2}O, NO2_{2}, N2_{2}O, and O3_{3}). This quality assessment was carried out on different timescales to examine what temporal signals are captured by the FTIR records, and to what extent. After 20 years of operation, the IZO NDACC FTIR observations have been found to be very consistent and reliable over time, demonstrating great potential for climate research. Long-term NDACC FTIR data sets, such as IZO, are indispensable tools for the investigation of atmospheric composition trends, multi-year phenomena, and complex climate feedback processes, as well as for the validation of past and present space-based missions and chemistry climate models
    corecore