Search results for "gass"
showing 10 items of 164 documents
UV camera-based monitoring SO2 flux on Mt. Etna
Validation of a novel Multi-Gas sensor for volcanic HCl alongside H
2016
Volcanic gas emission measurements inform predictions of hazard and atmospheric impacts. For these measurements, Multi-Gas sensors provide low-cost in situ monitoring of gas composition but to date have lacked the ability to detect halogens. Here, two Multi-Gas instruments characterized passive outgassing emissions from Mt. Etna’s (Italy) three summit craters, Voragine (VOR), North-east Crater (NEC) and Bocca Nuova (BN) on 2 October 2013. Signal processing (Sensor Response Model, SRM) approaches are used to analyse H2S/SO2 and HCl/SO2 ratios. A new ability to monitor volcanic HCl using miniature electrochemical sensors is here demonstrated. A “direct-exposure” Multi-Gas instrument contained…
Composition and distribution of volcanic gases inside the Lakki Caldera (Nisyros, Greece): preliminary results
2013
Unravelling textural heterogeneity in obsidian:shear-induced outgassing in the Rocche Rosse flow
2016
Obsidian flow emplacement is a complex and understudied aspect of silicic volcanism. Of particular importance is the question of how highly viscous magma can lose sufficient gas in order to erupt effusively as a lava flow. Using an array of methods we study the extreme textural heterogeneity of the Rocche Rosse obsidian flow in Lipari, a 2. km long, 100. m thick, ~. 800. year old lava flow, with respect to outgassing and emplacement mechanisms. 2D and 3D vesicle analyses and density measurements are used to classify the lava into four textural types: 'glassy' obsidian (<. 15% vesicles), 'pumiceous' lava (>. 40% vesicles), high aspect ratio, 'shear banded' lava (20-40% vesicles) and lo…
Seawater carbonate chemistry and percentage cover of macroalgal species at three locations at Vulcano, Italy
2017
Beneficial effects of CO2 on photosynthetic organisms will be a key driver of ecosystem change under ocean acidification. Predicting the responses of macroalgal species to ocean acidification is complex, but we demonstrate that the response of assemblages to elevated CO2 are correlated with inorganic carbon physiology. We assessed abundance patterns and a proxy for CO2:HCO3- use (delta 13C values) of macroalgae along a gradient of CO2 at a volcanic seep, and examined how shifts in species abundance at other Mediterranean seeps are related to macroalgal inorganic carbon physiology. Five macroalgal species capable of using both HCO3- and CO2 had greater CO2 use as concentrations increased. Th…
Los órganos amiboides de Ortega y García Bacca
2019
El presente artículo pretende exponer la posible influencia que la filosofía de José Ortega y Gasset ejerció sobre el filósofo español del exilio republicano Juan David García Bacca, con el fin de poder determinar hasta qué punto y, de qué modo, fue clave en la gestación del proyecto metafísico garcíabacquiano. This article aims to expose the possible influence that the philosophy of José Ortega y Gasset exerted on the Spanish philosopher of the Republican exile Juan David García Bacca, in order to determine to what extent and, how, was key in the gestation of Bacca’s metaphysical project.
PDMS membranes for feasible recovery of dissolved methane from AnMBR effluents
2020
[EN] This study aimed to evaluate the feasibility of degassing membrane (DM) technology for recovering dissolved methane from AnMBR effluents. For that purpose, a PDMS membrane module was operated for treating the effluent from an AnMBR prototype-plant, which treated urban wastewater (UWW) at ambient temperature. Different transmembrane pressures and liquid flow rates were applied for evaluating methane recovery efficiency. Maximum methane recoveries were achieved when increasing the vacuum pressure and reducing the liquid flow rate, reaching a maximum methane recovery efficiency of around 80% at a transmembrane pressure (TMP) of 0.8 bars and a treatment flow rate (Q(L)) of 50 L h(-1). The …
La perspectiva intercultural. Ortega y la hermenéutica
2018
En este artículo presento la perspectiva intercultural a partir de la doctrina orteguiana del punto de vista. Aunque Ortega no emplea en sus escritos el término “intercultural”, expongo de qué modo es posible entender su perspectivismo en términos interculturales. Para ello además de conectarlo con los planteamientos de dos de los principales autores de la tradición hermenéutica como son Hans-Georg Gadamer y Charles Taylor, destaco la dimensión intercultural de su perspectivismo. A lo largo del artículo critico posturas deficientes como son el relativismo, el etnocentrismo, el positivismo, el culturalismo y la beatería de la cultura. In this article, I present the intercultural perspective …
Operation of silicon photomultipliers as photosensors of liquid xenon detectors
2016
Silicon Photomultipliers as photosensors for liquid xenon detectors are an attractive alternative to photomultiplier tubes: liquid xenon detectors employed in low background experiments or compact Compton cameras can take advantage of the small sensor mass and dimensions, the larger light collection coming from a more packed tiling of the readout plane, and possibly a smaller cost per area. We investigate the operation in liquid xenon of samples developed by Ketek GmbH. To provide sensitivity to the liquid xenon scintillation light wavelength, 178 nm, the inactive entrance layer of the device has been thinned. The operation of such devices at temperatures as low as −100°C has been verified,…
Diffuse degassing of carbon dioxide at Somma-Vesuvius volcanic complex (Southern Italy) and its relation with regional tectonics
2004
Abstract A systematic survey of soil CO 2 concentrations was carried out on the flanks of Somma–Vesuvius volcano in order to constrain possible pathways responsible of carbon dioxide diffuse degassing taking place during the present state of quiescence. Measurements were performed at 1162 sites in late winter–spring 2000, highlighting that soil CO 2 concentrations range from 50 to 10500 ppmV. A statistical analysis was developed in order to define the threshold value of anomaly and separate the biogenic CO 2 component, produced by soil respiration, from the inorganic component of deep provenance. A computer routine was also elaborated to interpret the grid of CO 2 anomalous concentration va…