The Experts below are selected from a list of 4155 Experts worldwide ranked by ideXlab platform
D. Astrain - One of the best experts on this subject based on the ideXlab platform.
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Experimental Evidence of the Viability of Thermoelectric Generators to Power Volcanic Monitoring Stations.
Sensors, 2020Co-Authors: Leyre Catalan, Amaia Garacochea, Alvaro Casi, Miguel Araiz, Patricia Aranguren, D. AstrainAbstract:Although there is an important lack of commercial thermoelectric applications mainly due to their low efficiency, there exist some cases in which thermoelectric generators are the best option thanks to their well-known advantages, such as reliability, lack of maintenance and scalability. In this sense, the present paper develops a novel application in order to supply power to volcanic monitoring stations, making them completely autonomous. These stations become indispensable in any volcano since they are able to predict eruptions. Nevertheless, they present energy supply difficulties due to the absence of the power grid, the remote access, and the climatology. As a solution, this work has designed a new integral system composed of thermoelectric generators with high efficiency heat exchangers, and its associated electronics, developed thanks to Internet of Things (IoT) technologies. Thus, the heat emitted from volcanic Fumaroles is transformed directly into electricity with thermoelectric generators with passive heat exchangers based on phase change, leading to a continuous generation without moving parts that powers different sensors, the information of which is emitted via LoRa. The viability of the solution has been demonstrated both at the laboratory and at a real volcano, Teide (Canary Islands, Spain), where a compact prototype has been installed in an 82 °C fumarole. The results obtained during more than five months of operation prove the robustness and durability of the developed generator, which has been in operation without maintenance and under all kinds of meteorological conditions, leading to an average generation of 0.54 W and a continuous emission over more than 14 km.
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prospects of autonomous volcanic monitoring stations experimental investigation on thermoelectric generation from Fumaroles
Sensors, 2020Co-Authors: Leyre Catalan, Miguel Araiz, Patricia Aranguren, Pedro A Hernandez, Nemesio M Perez, German Padilla, Celestino Garcia De La Noceda, Jose Francisco Albert, D. AstrainAbstract:Fumaroles represent evidence of volcanic activity, emitting steam and volcanic gases at temperatures between 70 and 100 ∘ C . Due to the well-known advantages of thermoelectricity, such as reliability, reduced maintenance and scalability, the present paper studies the possibilities of thermoelectric generators, devices based on solid-state physics, to directly convert Fumaroles heat into electricity due to the Seebeck effect. For this purpose, a thermoelectric generator composed of two bismuth-telluride thermoelectric modules and heat pipes as heat exchangers was installed, for the first time, at Teide volcano (Canary Islands, Spain), where Fumaroles arise in the surface at 82 ∘ C . The installed thermoelectric generator has demonstrated the feasibility of the proposed solution, leading to a compact generator with no moving parts that produces a net generation between 0.32 and 0 . 33 W per module given a temperature difference between the heat reservoirs encompassed in the 69- 86 ∘ C range. These results become interesting due to the possibilities of supplying power to the volcanic monitoring stations that measure the precursors of volcanic eruptions, making them completely autonomous. Nonetheless, in order to achieve this objective, corrosion prevention measures must be taken because the hydrogen sulfide contained in the Fumaroles reacts with steam, forming sulfuric acid.
C W Haberle - One of the best experts on this subject based on the ideXlab platform.
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a low diversity microbiota inhabits extreme terrestrial basaltic terrains and their Fumaroles implications for the exploration of mars
Astrobiology, 2019Co-Authors: Charles S Cockell, Jesse P Harrison, Adam R H Stevens, Samuel J Payler, S S Hughes, Shannon Kobs E Nawotniak, Allyson L Brady, R C Elphic, C W HaberleAbstract:A major objective in the exploration of Mars is to test the hypothesis that the planet hosted life. Even in the absence of life, the mapping of habitable and uninhabitable environments is an essential task in developing a complete understanding of the geological and aqueous history of Mars and, as a consequence, understanding what factors caused Earth to take a different trajectory of biological potential. We carried out the aseptic collection of samples and comparison of the bacterial and archaeal communities associated with basaltic Fumaroles and rocks of varying weathering states in Hawai'i to test four hypotheses concerning the diversity of life in these environments. Using high-throughput sequencing, we found that all these materials are inhabited by a low-diversity biota. Multivariate analyses of bacterial community data showed a clear separation between sites that have active Fumaroles and other sites that comprised relict Fumaroles, unaltered, and syn-emplacement basalts. Contrary to our hypothesis that high water flow environments, such as Fumaroles with active mineral leaching, would be sites of high biological diversity, alpha diversity was lower in active Fumaroles compared to relict or nonfumarolic sites, potentially due to high-temperature constraints on microbial diversity in fumarolic sites. A comparison of these data with communities inhabiting unaltered and weathered basaltic rocks in Idaho suggests that bacterial taxon composition of basaltic materials varies between sites, although the archaeal communities were similar in Hawai'i and Idaho. The taxa present in both sites suggest that most of them obtain organic carbon compounds from the atmosphere and from phototrophs and that some of them, including archaeal taxa, cycle fixed nitrogen. The low diversity shows that, on Earth, extreme basaltic terrains are environments on the edge of sustaining life with implications for the biological potential of similar environments on Mars and their exploration by robots and humans.
Jesse P Harrison - One of the best experts on this subject based on the ideXlab platform.
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a low diversity microbiota inhabits extreme terrestrial basaltic terrains and their Fumaroles implications for the exploration of mars
Astrobiology, 2019Co-Authors: Charles S Cockell, Jesse P Harrison, Adam R H Stevens, Samuel J Payler, S S Hughes, Shannon Kobs E Nawotniak, Allyson L Brady, R C Elphic, C W HaberleAbstract:A major objective in the exploration of Mars is to test the hypothesis that the planet hosted life. Even in the absence of life, the mapping of habitable and uninhabitable environments is an essential task in developing a complete understanding of the geological and aqueous history of Mars and, as a consequence, understanding what factors caused Earth to take a different trajectory of biological potential. We carried out the aseptic collection of samples and comparison of the bacterial and archaeal communities associated with basaltic Fumaroles and rocks of varying weathering states in Hawai'i to test four hypotheses concerning the diversity of life in these environments. Using high-throughput sequencing, we found that all these materials are inhabited by a low-diversity biota. Multivariate analyses of bacterial community data showed a clear separation between sites that have active Fumaroles and other sites that comprised relict Fumaroles, unaltered, and syn-emplacement basalts. Contrary to our hypothesis that high water flow environments, such as Fumaroles with active mineral leaching, would be sites of high biological diversity, alpha diversity was lower in active Fumaroles compared to relict or nonfumarolic sites, potentially due to high-temperature constraints on microbial diversity in fumarolic sites. A comparison of these data with communities inhabiting unaltered and weathered basaltic rocks in Idaho suggests that bacterial taxon composition of basaltic materials varies between sites, although the archaeal communities were similar in Hawai'i and Idaho. The taxa present in both sites suggest that most of them obtain organic carbon compounds from the atmosphere and from phototrophs and that some of them, including archaeal taxa, cycle fixed nitrogen. The low diversity shows that, on Earth, extreme basaltic terrains are environments on the edge of sustaining life with implications for the biological potential of similar environments on Mars and their exploration by robots and humans.
Leyre Catalan - One of the best experts on this subject based on the ideXlab platform.
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Experimental Evidence of the Viability of Thermoelectric Generators to Power Volcanic Monitoring Stations.
Sensors, 2020Co-Authors: Leyre Catalan, Amaia Garacochea, Alvaro Casi, Miguel Araiz, Patricia Aranguren, D. AstrainAbstract:Although there is an important lack of commercial thermoelectric applications mainly due to their low efficiency, there exist some cases in which thermoelectric generators are the best option thanks to their well-known advantages, such as reliability, lack of maintenance and scalability. In this sense, the present paper develops a novel application in order to supply power to volcanic monitoring stations, making them completely autonomous. These stations become indispensable in any volcano since they are able to predict eruptions. Nevertheless, they present energy supply difficulties due to the absence of the power grid, the remote access, and the climatology. As a solution, this work has designed a new integral system composed of thermoelectric generators with high efficiency heat exchangers, and its associated electronics, developed thanks to Internet of Things (IoT) technologies. Thus, the heat emitted from volcanic Fumaroles is transformed directly into electricity with thermoelectric generators with passive heat exchangers based on phase change, leading to a continuous generation without moving parts that powers different sensors, the information of which is emitted via LoRa. The viability of the solution has been demonstrated both at the laboratory and at a real volcano, Teide (Canary Islands, Spain), where a compact prototype has been installed in an 82 °C fumarole. The results obtained during more than five months of operation prove the robustness and durability of the developed generator, which has been in operation without maintenance and under all kinds of meteorological conditions, leading to an average generation of 0.54 W and a continuous emission over more than 14 km.
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prospects of autonomous volcanic monitoring stations experimental investigation on thermoelectric generation from Fumaroles
Sensors, 2020Co-Authors: Leyre Catalan, Miguel Araiz, Patricia Aranguren, Pedro A Hernandez, Nemesio M Perez, German Padilla, Celestino Garcia De La Noceda, Jose Francisco Albert, D. AstrainAbstract:Fumaroles represent evidence of volcanic activity, emitting steam and volcanic gases at temperatures between 70 and 100 ∘ C . Due to the well-known advantages of thermoelectricity, such as reliability, reduced maintenance and scalability, the present paper studies the possibilities of thermoelectric generators, devices based on solid-state physics, to directly convert Fumaroles heat into electricity due to the Seebeck effect. For this purpose, a thermoelectric generator composed of two bismuth-telluride thermoelectric modules and heat pipes as heat exchangers was installed, for the first time, at Teide volcano (Canary Islands, Spain), where Fumaroles arise in the surface at 82 ∘ C . The installed thermoelectric generator has demonstrated the feasibility of the proposed solution, leading to a compact generator with no moving parts that produces a net generation between 0.32 and 0 . 33 W per module given a temperature difference between the heat reservoirs encompassed in the 69- 86 ∘ C range. These results become interesting due to the possibilities of supplying power to the volcanic monitoring stations that measure the precursors of volcanic eruptions, making them completely autonomous. Nonetheless, in order to achieve this objective, corrosion prevention measures must be taken because the hydrogen sulfide contained in the Fumaroles reacts with steam, forming sulfuric acid.
Fraser Goff - One of the best experts on this subject based on the ideXlab platform.
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atmospheric mercury emissions from substrates and Fumaroles associated with three hydrothermal systems in the western united states
Journal of Geophysical Research, 2006Co-Authors: Cathy J Janik, Fraser Goff, Dale Counce, Deborah Bergfeld, Mark A Engle, Mae Sexauer Gustin, James J RytubaAbstract:[1] This paper quantifies atmospheric mercury (Hg) emissions from substrates and Fumaroles associated with three hydrothermal systems: Lassen Volcanic Center, California (LVC); Yellowstone Caldera, Wyoming (YC); and Dixie Valley, Nevada (DV). Substrate Hg fluxes were measured using field chamber methods at thermal and nonthermal sites. The highest Hg fluxes (up to 541 ng m−2 h−1) were measured at thermal active areas. Fluxes from altered and unaltered nonthermal sites were 98%). At YC, substrate Hg emissions were dominated (50 to 90%) by acidically altered thermal areas. Substrate emissions at DV were low and primarily from nonthermal areas (66% to 75%). Fumarole emissions at LVC (91–146 kg yr−1) and YC (0.18–1.6 kg yr−1 for Mud Volcano) were estimated by applying Hg:H2O and Hg:CO2 ratios in hydrothermal gas samples to H2O and CO2 emissions. Applying total area-average emissions from substrates and thermal features at LVC, YC, and DV to similar systems across the conterminous United States, yearly atmospheric Hg emissions from active hydrothermal systems are projected to be 1.3–2.1 Mg.
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elevated carbon dioxide flux at the dixie valley geothermal field nevada relations between surface phenomena and the geothermal reservoir
Chemical Geology, 2001Co-Authors: Deborah Bergfeld, Fraser Goff, C J JanikAbstract:Abstract In the later part of the 1990s, a large die-off of desert shrubs occurred over an approximately 1 km 2 area in the northwestern section of the Dixie Valley (DV) geothermal field. This paper reports results from accumulation-chamber measurements of soil CO 2 flux from locations in the dead zone and stable isotope and chemical data on fluids from Fumaroles, shallow wells, and geothermal production wells within and adjacent to the dead zone. A cumulative probability plot shows three types of flux sites within the dead zone: locations with a normal background CO 2 flux (7 g m −2 day −1 ); moderate flux sites displaying “excess” geothermal flux; and high flux sites near young vents and Fumaroles. A maximum CO 2 flux of 570 g m −2 day −1 was measured at a location adjacent to a fumarole. Using statistical methods appropriate for lognormally distributed populations of data, estimates of the geothermal flux range from 7.5 t day −1 from a 0.14-km 2 site near the Stillwater Fault to 0.1 t day −1 from a 0.01-km 2 location of steaming ground on the valley floor. Anomalous CO 2 flux is positively correlated with shallow temperature anomalies. The anomalous flux associated with the entire dead zone area declined about 35% over a 6-month period. The decline was most notable at a hot zone located on an alluvial fan and in the SG located on the valley floor. Gas geochemistry indicates that older established Fumaroles along the Stillwater Fault and a 2-year-old vent in the lower section of the dead zone discharge a mixture of geothermal gases and air or gases from air-saturated meteoric water (ASMW). Stable isotope data indicate that steam from the smaller Fumaroles is produced by ≈100°C boiling of these mixed fluids and reservoir fluid. Steam from the Senator fumarole (SF) and from shallow wells penetrating the dead zone are probably derived by 140°C to 160°C boiling of reservoir fluid. Carbon-13 isotope data suggest that the reservoir CO 2 is produced mainly by thermal decarbonation of hydrothermal calcite in veins that cut reservoir rocks. Formation of the dead zone is linked to the reservoir pressure decline caused by continuous reservoir drawdown from 1986 to present. These reservoir changes have restricted flow and induced boiling in a subsurface hydrothermal outflow plume extending from the Stillwater Fault southeast toward the DV floor. We estimate that maximum CO 2 flux in the upflow zone along the Stillwater Fault in 1998 was roughly seven to eight times greater than the pre-production flux in 1986. The eventual decline in CO 2 flux reflects the drying out of the outflow plume.
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Addition of magmatic volatiles into the hot spring waters of loowit canyon, Mount St. Helens, Washington, USA
Bulletin of Volcanology, 1993Co-Authors: Lisa Shevenell, Fraser GoffAbstract:Geochemical studies on cold meteoric waters, post-1980 hot spring waters, fumarole emissions from the dacite dome, and volcanic rocks at Mount St. Helens (MSH) from 1985 to 1989 show that magmatic volatiles are involved in the formation of a new hydrothermal system. Hot spring waters are enriched in δ^18O by as much as 2‰ and display enrichments in δD relative to cold waters. A well-defined isotopic trend is displayed by the isotopic composition of a>400°C fumarole condensate collected from the central crater in 1980 (-33‰ δD, +6‰ δ^18O), of condensate samples collected on the dome, and of cold meteoric and hot spring waters. The trend indicates that mixing occurs between local meteoric water and magmatic water degassing from the dacite dome. Between 30 and 70% magmatic water is present in the dome fumarole discharges and ≈10% magnatic water has been added to the waters of the hydrothermal system. Relations between Cl, SO_4 and HCO_3 indicate that the hot spring waters are immature volcanic waters formed by reaction of rocks with waters generated by absorption of acidic volcanic fluids. In addition, the B/Cl ratios of the spring waters are similar to the B/Cl ratios of the fumarole condensates (≈0.02), values of δ^13C in the HCO_3 of the hot springs (-9.5 to-13.5‰) are similar to the magmatic value at MSH (-10.5‰), and the ^3He/^4He ratio, relative to air, in a hot spring water is 5.7, suggesting a magmatic origin for this component.
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hydrogeochemical exploration of geothermal prospects in the tecuamburro volcano region guatemala
Geothermics, 1992Co-Authors: Cathy J Janik, Fraser Goff, Lynne Fahlquist, Andrew I Adams, Alfredo M Roldan, Steve J Chipera, P E Trujillo, Dale CounceAbstract:Abstract Chemical and isotopic analyses of thermal and nonthermal waters and of gases from springs and Fumaroles are used to evaluate the geothermal potential of the Tecuamburro Volcano region, Guatemala. Chemically distinct geothermal surface manifestations generally occur in separate hydrogeologic areas within this 400 km 2 region: low-pressure Fumaroles with temperatures near local boiling occur at 1470 m elevation in a sulfur mine near the summit of Tecuamburro Volcano; non-boiling acid-sulfate hot springs and mud pots are restricted to the Laguna Ixpaco area, about 5 km NNW of the sulfur mine and 350–400 m lower in elevation; steam-heated and thermal-meteoric waters are found on the flanks of Tecuamburro Volcano and several kilometers to the north in the andesitic highland, where the Infernitos fumarole (97°C at 1180 m) is the primary feature; neutral-chloride hot springs discharge along Rio Los Esclavos, principally near Colmenares at 490 m elevation, about 8–10 km SE of Infernitos. Maximum geothermometer temperatures calculated from Colmenares neutral-chloride spring compositions are ∼180° C , whereas maximum subsurface temperatures based on Laguna Ixpaco gas compositions are ∼310° C . An exploration core hole drilled to a depth of 808 m about 0.3 km south of Laguna Ixpaco had a bottom-hole temperature of 238°C but did not produce sufficient fluids to confirm or chemically characterize a geothermal reservoir. Hydrogeochemical data combined with regional geologic interpretations indicate that there are probably two hydrothermal-convection systems, which are separated by a major NW-trending structural boundary, the Ixpaco fault. One system with reservoir temperatures near 300°C lies beneath Tecuamburro Volcano and consists of a large vapor zone that feeds steam to the Laguna Ixpaco area, with underlying hot water that flows laterally to feed a small group of warm, chloriderich springs SE of Tecuamburro Volcano. The other system is located beneath the Infernitos area in the andesitic highland and consists of a lower-temperature (150–190°C) reservoir with a large natural discharge that feeds the Colmenares hot springs.
