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Juan Manuel Madariaga - One of the best experts on this subject based on the ideXlab platform.
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characterization of ferruginous cements related with weathering of slag in a temperate anthropogenic beachrock
Science of The Total Environment, 2017Co-Authors: N Arrieta, Ane Iturregui, I Martinezarkarazo, Xabier Murelaga, Juan Ignacio Baceta, Alberto De Diego, M A Olazabal, Juan Manuel MadariagaAbstract:This work outlines a temperate latitude beachrock occurrence, which represents the legacy of heavy anthropogenic environmental disturbance. The units contain high amounts of slag and iron-rich wastes derived from metallurgical activities that attest the impact of the past industrial development on such coastal systems. The exposition of the anthropogenic wastes to weathering processes, such as the influence of marine aerosols and the Chemical attack of acid gases like the SOx coming from the nearby urban-industrial atmosphere, gave rise to the formation of early diagenetic ferruginous cements. A new analytical methodology based on the combination of micro-Raman spectroscopy (MRS), Raman Chemical imaging, SEM-EDS and the Structural and Chemical Analyzer (SCA, an emerging system that hyphenates micro-Raman and SEM-EDS), was applied for the first time to characterize the ferruginous cements. The MRS analyses revealed Fe2+/Fe3+ oxides and oxyhydroxides, CaCO3 polymorphs and less frequently silicates. The Fe mineral species detected were hydrated goethite, hematite, magnetite, magnesioferrite, lepidocrocite and goethite. Complementary Raman imaging, SEM-EDS and SCA analyses unraveled the preferential distribution of hydrated goethite. The identified iron mineral phases are weathering sub-products of hematite commonly derived from atmospheric/aqueous leaching processes triggered by the Chemical attack of the acid gases. EDS showed the existence of other elements such as Si, Mg, Cl, Na, Al, K and sporadically S that indicated the importance of permeability, atmospheric deposition and the acid attack. Additionally, calcite and gypsum minerals also evidenced the action of meteoric waters, dry deposition processes or the attack of SOx acid gases. The presence of such compounds is modifying the cement stratigraphy and suggests that the dissolution of carbonates is currently taking place. Those facts influence the erosive susceptibility and the release of the anthropogenic materials trapped originally in the beachrocks, which could act as potential secondary sources of contaminants to the coastal environment.
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Structural and Chemical Analyzer system for the analysis of deposited airborne particles and degradation compounds present on the surface of outdoor weathering steel objects
Microchemical Journal, 2015Co-Authors: Julene Aramendia, Leticia Gomez-nubla, Kepa Castro, Juan Manuel MadariagaAbstract:Abstract The weathering steel is a high strength low alloy special kind of steel theoretically resistant to the atmospheric corrosion. In the present work, several weathering steel structures exposed to the urban atmosphere were analyzed by means of structural and Chemical Analyzer, a spectroscopic system that combines micro-Raman and SEM/EDS microscopy measurements in the same spot, in order to detect the deposited atmospheric material and to characterize it. Several kinds of silicates and aluminosilicates containing particles were identified on the steel surface of the analyzed works. In addition, other atmospheric particles such as calcite, charcoal and chromium rich particles were detected together with several compounds coming from the reaction of the steel and the deposited particles with the acid gases of the atmosphere. These particles have negative effects in the conservation of the weathering steel changing the visual appearance of the surface and decreasing the atmospheric resistance of the material.
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Emerging application of a structural and Chemical Analyzer for the complete characterization of metal-rich particulate matter.
Analytical chemistry, 2013Co-Authors: Naiara Goienaga, A. Sarmiento, Maitane Olivares, Jose Antonio Carrero, Luis Ángel Fernández, Juan Manuel MadariagaAbstract:Clean air is considered to be a basic requirement of human health and well-being. An increasing range of adverse health effects has been linked to air pollution, at ever-lower concentrations. This research shows the newly developed Structural and Chemical Analyzer (SCA) to be a successful combination of Raman spectroscopy and scanning electron microscope-energy dispersive X-rays that opens up new insight into the composition of particulate matter (PM). The results obtained with soil and lichen samples demonstrate the capability of the technique to obtain elemental and molecular information of every single atmospheric PM focused at the micrometer and submicrometer levels. The SCA approach permitted the individual PM analysis, allowing the identification of the molecular (most commonly as sulphides, sulphates, carbonates, or oxides) form in which several hazardous metals (Zn, Pb, Cu, etc.) are evolved into potentially inhalable PM. During the present research, the synchronization of both techniques at a time revealed the morphological, elemental, and molecular forms of metal-rich PM, avoiding some analysis precautions and making the sample preparation and measurement steps more dynamic. In addition, the thermodynamic simulations carried out with the information obtained were helpful to differentiate whether the PM may be retained in the alveoli (i.e., galena) or if it may be dissolved and pass into the bloodstream (i.e., plattnerite).
Andreas Held - One of the best experts on this subject based on the ideXlab platform.
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A Chemical Analyzer for charged ultrafine particles
Atmospheric Measurement Techniques, 2013Co-Authors: Stefan Gonser, Andreas HeldAbstract:Abstract. New particle formation is a frequent phenomenon in the atmosphere and of major significance for the Earth's climate and human health. To date the mechanisms leading to the nucleation of particles as well as to aerosol growth are not completely understood. A lack of appropriate measurement equipment for online analysis of the Chemical composition of freshly nucleated particles is one major limitation. We have developed a Chemical Analyzer for Charged Ultrafine Particles (CAChUP) capable of analyzing particles with diameters below 30 nm. A bulk of size-separated particles is collected electrostatically on a metal filament, resistively desorbed and subsequently analyzed for its molecular composition in a time of flight mass spectrometer. We report on technical details as well as characterization experiments performed with the CAChUP. Our instrument was tested in the laboratory for its detection performance as well as for its collection and desorption capabilities. The manual application of defined masses of camphene (C10H16) to the desorption filament resulted in a detection limit between 0.5 and 5 ng, and showed a linear response of the mass spectrometer. Flow tube experiments of 25 nm diameter secondary organic aerosol from ozonolysis of alpha-pinene also showed a linear relation between collection time and the mass spectrometer's signal intensity. The resulting mass spectra from the collection experiments are in good agreement with published work on particles generated by the ozonolysis of alpha-pinene. A sensitivity study shows that the current setup of CAChUP is ready for laboratory measurements and for the observation of new particle formation events in the field.
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A Chemical Analyzer for charged ultrafine particles
Atmospheric Measurement Techniques Discussions, 2013Co-Authors: Stefan Gonser, Andreas HeldAbstract:Abstract. New particle formation is a frequent phenomenon in the atmosphere and of major significance for the earth's climate and human health. To date the mechanisms leading to the nucleation of particles as well as to aerosol growth are not completely understood. A lack of appropriate measurement equipment for online analysis of the Chemical composition of freshly nucleated particles is one major limitation. We have developed a Chemical Analyzer for Charged Ultrafine Particles (CAChUP) capable of analyzing particles with diameters below 30 nm. A bulk of size separated particles is collected electrostatically on a metal filament, resistively desorbed and consequently analyzed for its molecular composition in a time of flight mass spectrometer. We report of technical details as well as characterization experiments performed with the CAChUP. Our instrument was tested in the laboratory for its detection performance as well as for its collection and desorption capabilities. The manual application of known masses of camphene (C10H16) to the desorption filament resulted in a detection limit between 0.5 and 5 ng, and showed a linear response of the mass spectrometer. Flow tube experiments of 25 nm diameter secondary organic aerosol from ozonolysis of alpha-pinene also showed a linear relation between collection time and the mass spectrometer's signal intensity. The resulting mass spectra from the collection experiments are in good agreement with published work on particles generated by the ozonolysis of alpha-pinene. A sensitivity study shows that the current setup of CAChUP is ready for laboratory measurements and for the observation of new particle formation events in the field.
H. Edwards - One of the best experts on this subject based on the ideXlab platform.
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Exploration of Ellsworth Subglacial Lake: a concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake
Reviews in Environmental Science and Bio Technology, 2007Co-Authors: M.j. Siegert, A. Behar, M. Bentley, D. Blake, S. Bowden, P. Christoffersen, C. Cockell, H. Corr, D. C. Cullen, H. EdwardsAbstract:Antarctic subglacial lakes have, over the past few years, been hypothesised to house unique forms of life and hold detailed sedimentary records of past climate change. Testing this hypothesis requires in situ examinations. The direct measurement of subglacial lakes has been considered ever since the largest and best-known lake, named Lake Vostok, was identified as having a deep water-column. The Subglacial Antarctic Lake Environments (SALE) programme, set up by the Scientific Committee on Antarctic Research (SCAR) to oversee subglacial lakes research, state that prior exploration of smaller lakes would be a “prudent way forward”. Over 145 subglacial lakes are known to exist in Antarctica, but one lake in West Antarctica, officially named Ellsworth Subglacial Lake (referred to hereafter as Lake Ellsworth), stands out as a candidate for early exploration. A consortium of over 20 scientists from seven countries and 14 institutions has been assembled to plan the exploration of Lake Ellsworth. An eight-year programme is envisaged: 3 years for a geophysical survey, 2 years for equipment development and testing, 1 year for field planning and operation, and 2 years for sample analysis and data interpretation. The science experiment is simple in concept but complex in execution. Lake Ellsworth will be accessed using hot water drilling. Once lake access is achieved, a probe will be lowered down the borehole and into the lake. The probe will contain a series of instruments to measure biological, Chemical and physical characteristics of the lake water and sediments, and will utilise a tether to the ice surface through which power, communication and data will be transmitted. The probe will pass through the water column to the lake floor. The probe will then be pulled up and out of the lake, measuring its environment continually as this is done. Once at the ice surface, any water samples collected will be taken from the probe for laboratory analysis (to take place over subsequent years). The duration of the science mission, from deployment of the probe to its retrieval, is likely to take between 24 and 36 h. Measurements to be taken by the probe will provide data about the following: depth, pressure, conductivity and temperature; pH levels; biomolecules (using life marker chips); anions (using a Chemical Analyzer); visualisation of the environment (using cameras and light sources); dissolved gases (using chromatography); and morphology of the lake floor and sediment structures (using sonar). After the probe has been retrieved, a sediment corer may be dropped into the lake to recover material from the lake floor. Finally, if time permits, a thermistor string may be left in the lake water to take time-dependent measurements of the lake’s water column over subsequent years. Given that the comprehensive geophysical survey of the lake will take place in two seasons during 2007–2009, a two-year instrument and logistic development phase from 2008 (after the lake’s bathymetry has been assessed) makes it possible that the exploration of Lake Ellsworth could take place at the beginning of the next decade.
Pierre-marie Sarradin - One of the best experts on this subject based on the ideXlab platform.
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CHEMINI: A new in situ Chemical MINIaturized Analyzer
Deep Sea Research Part I: Oceanographic Research Papers, 2009Co-Authors: Renaud Vuillemin, D. Le Roux, P. Dorval, Karenn Bucas, J.p. Sudreau, Michel Hamon, C. Le Gall, Pierre-marie SarradinAbstract:Abstract “CHEMINI” is a new instrument developed for the measurement of seawater Chemical parameters. It is a mono-parameter in situ Chemical Analyzer based on flow injection analysis and colorimetric detection. The deep-sea version of CHEMINI combines two modules to perform the analysis of dissolved iron [Fe (II) or Fe (II+III)] and total sulphide (H 2 S+HS − +S 2− ) up to 6000 m depth. Detection limits are, respectively, 0.3 and 0.1 μM for iron and sulphide. The system proved highly reliable during the MoMARETO cruise on the Mid-Atlantic Ridge. The two CHEMINIs were used to describe the Chemical environment in 12 mussel beds on the Tour Eiffel hydrothermal edifice.
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A new Chemical Analyzer for in situ measurement of nitrate and total sulfide over hydrothermal vent biological communities
Marine Chemistry, 2000Co-Authors: N. Le Bris, Pierre-marie Sarradin, Dominique Birot, A.-m Alayse-danetAbstract:A new submersible Chemical Analyzer, ALCHIMIST (AnaLyseur CHIMique In SiTu), based on colorimetric detection and flow injection analysis (FIA), was adapted to allow in situ measurements of nitrate+nitrite (N+N) and total dissolved sulfide (∑S) in the deep sea hydrothermal environment. Before in situ trials, the influence of hydrostatic pressure and temperature on the analytical responses was examined under simulated conditions (1–300×105 Pa, 5–25°C). First trials were performed during dives of the Remotely Operated Vehicle (ROV), VICTOR 6000, over the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge). ALCHIMIST, installed on the ROV, enabled simultaneous N+N and ∑S calibration and measurements at 1650 m depth, at a rate of 22 analyses per hour. At depth, the precision of the in situ ∑S and N+N measurements is estimated to be, respectively, 1.1% and 0.8%. The detection limit is 0.8 μM for ∑S and 0.5 μM for N+N. At a vent site of the Lucky Strike area, ALCHIMIST enabled to resolve, at the decimeter scale, the Chemical gradients which characterize the patchy distribution of hydrothermal fauna. Additionally, temperature–concentration relationships offered further information on the processes controlling the chemistry of the habitats. Like former in situ Analyzers used in this field, this new instrument should be valuable to characterize the physico-Chemical characteristics of vent fauna environment.
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A multipurpose submersible Chemical Analyzer for various applications in marine environment
IEEE Oceanic Engineering Society. OCEANS'98. Conference Proceedings (Cat. No.98CH36259), 1Co-Authors: Dominique Birot, N. Le Bris, Pierre-marie Sarradin, B. Leide, E. Menut, Jean-francois Rolin, Jean-claude Caprais, Alexis Khripounoff, Stéphane Blain, J. FlochAbstract:Submersible Chemical Analyzers have been designed in the authors' laboratories to satisfy various needs of oceanographers in regards of in situ Chemical measurements. These developments are based on the concepts of flow methods and of modular electronic architecture. Advantages of such concepts are first briefly mentioned. The characteristics of these instruments are presented through the description of a specific Analyzer dedicated to simultaneous and high frequency measurements of nitrate and silicate in the water column. First sea trials results obtained with this device are then given and different Analyzers devoted to various applications are finally briefly described.
A.-m Alayse-danet - One of the best experts on this subject based on the ideXlab platform.
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A new Chemical Analyzer for in situ measurement of nitrate and total sulfide over hydrothermal vent biological communities
Marine Chemistry, 2000Co-Authors: N. Le Bris, Pierre-marie Sarradin, Dominique Birot, A.-m Alayse-danetAbstract:A new submersible Chemical Analyzer, ALCHIMIST (AnaLyseur CHIMique In SiTu), based on colorimetric detection and flow injection analysis (FIA), was adapted to allow in situ measurements of nitrate+nitrite (N+N) and total dissolved sulfide (∑S) in the deep sea hydrothermal environment. Before in situ trials, the influence of hydrostatic pressure and temperature on the analytical responses was examined under simulated conditions (1–300×105 Pa, 5–25°C). First trials were performed during dives of the Remotely Operated Vehicle (ROV), VICTOR 6000, over the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge). ALCHIMIST, installed on the ROV, enabled simultaneous N+N and ∑S calibration and measurements at 1650 m depth, at a rate of 22 analyses per hour. At depth, the precision of the in situ ∑S and N+N measurements is estimated to be, respectively, 1.1% and 0.8%. The detection limit is 0.8 μM for ∑S and 0.5 μM for N+N. At a vent site of the Lucky Strike area, ALCHIMIST enabled to resolve, at the decimeter scale, the Chemical gradients which characterize the patchy distribution of hydrothermal fauna. Additionally, temperature–concentration relationships offered further information on the processes controlling the chemistry of the habitats. Like former in situ Analyzers used in this field, this new instrument should be valuable to characterize the physico-Chemical characteristics of vent fauna environment.