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Showing 1 to 19 of 19 for “"carbonic acid"”.
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The Carbon Budget of the Mekong River Basin: A Spatial and Temporal Study of Chemical Weathering
The chemical weathering of silicate rocks with carbonic acid is thought to play an important role in the consumption of atmospheric carbon dioxide (CO$_{2}$), which regulates global climate over million--year timescales. However, the climatic implications of chemical weathering of carbonate rocks …
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The Effect of Turbulent Flow on Corrosion of Mild Steel in High Partial CO<sub>2</sub> Environments
… that precedes the direct reduction of carbonic acid. The effect of temperature (25<sup>o</sup> C, 50<sup>o</sup> C, and 80<sup>o</sup> C) at CO<sub>2</sub> partial pressure of 10 and 80 bar and at pH 3.0 and pH4.0 showed that the increase in temperature considerably accelerated …
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Significance of nanosilica incorporation in type G oil well cement pastes
… progression analysis and quantification after carbonic acid exposure testing. Degradation testing was performed by simulating conditions of geosequestration in a sandstone formation at a depth of roughly 1 km. These conditions were created by bubbling CO2 into a heated vessel containing 0.5 M …
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Study of reactive flow, ground deformation and real-time tomography with applications on CO₂ sequestration
… new computational model on the reactive flow of carbonic acid in limestone, an assessment of the surface uplift owing to sequestration of CO₂ in a carbonate saline aquifer, and a validation of a new, real-time, tomography method that monitors the velocity change resulting from hydraulic …
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Assessing landscape and seasonal controls on CO2 fluxes in a karst sinkhole
… carbon dioxide (CO2) reacts with water to form carbonic acid, which then weathers carbonate rocks. However, CO2 can also move through the subsurface via gas diffusion, a process that is not well-understood in karst systems. This study focused on quantifying CO2 diffusion within a karst sinkhole. …
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Scanning Methods as Monitoring, Verification, and Accounting tools for CO₂ Sequestration in Unconventional Gas Reservoirs
… results before and after the impregnation of the carbonic acid. The micro CT data in Avizo Fire© was used calculate an increase in cleat permeability by 25%. The increase of major flow pathways is caused by the dissolution of carbonates. Changes in the structures were observed qualitatively …
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Geochemical and geomechanical alteration of sandstone reservoir rock and shale caprock under representative geological carbon sequestration conditions
… dissolution of CO₂ into reservoir brine forms carbonic acid which can react with pH-sensitive minerals, affecting the geomechanical properties of the formation. This dissertation explores the impact of geochemical reactions of low-pH brine on the geomechanical properties of sandstone reservoir …
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Controlling kinetic branching in C0₂-to-fuels catalysis
… transfer from bicarbonate, hydronium, and/or carbonic acid to form adsorbed H species, followed by sequential one electron, one proton transfer or H recombination reactions. We elucidate the differential CO electrosorption dynamics on polycrystalline Au and Cu surfaces using …
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Evolution of chemical composition along river drainage networks
… of primary reactive minerals, rather than carbonic acid concentrations, limits weathering.</p><p>In the temperate Bagmati drainage system in Kathmandu valley, Nepal, population density appears to be the most fundamental control on the chemistry of surface waters. Concentrations in the …
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Impact of Isotopic Heterogeneity in Shallow Systems on Modeling of Stormflow Generation
… primary carbon sources, calcite and soil-derived carbonic acid, do not appear to be appreciably overprinted by exchange reactions, biological recycling, or degassing; hence, 0^13C seems to be a useful semi-conservative tracer of water flowpaths and carbon sources.
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Investigation into the start-up and operation of upflow anaerobic sludge bed reactors
… of NH3 were the primary causes of the acidity generation. A fixed-conversion model of the digester pH was developed to investigate the conversions of the relevant weak acid and base species present and the effects of these conversions on the digester pH. It was found that the …
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Spectroscopic study of photon, ion and electron stimulated molecular synthesis in astrophysical ices
… the production of H<sub>2</sub>CO<sub>3</sub> (carbonic acid) and CO investigated. The production of CO and CO<sub>3</sub> is described in UV irradiation experiments of mixed H<sub>2</sub>O:CO<sub>2</sub> ices. Particular attention is paid to the infrared band profile of CO in each of the …
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Herstellung und Charakterisierung carbonsäuremodifizierter Sol-Gel-Vorstufen von Mullit
Nach dem Sol-Gel-Verfahren wurden carbonsäuremodifizierte Mullitvorstufen hergestellt und charakterisiert. Dabei wurde die Kettenlänge der zur Synthese der Sole verwendeten Carbonsäuren variiert. Es zeigte sich, dass die säurekatalysierte Kondensation der Siliciumkomponente zu linearen, oligomeren …
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Developing NMR/MRI Techniques for Characterisation of Reactive Transport in Porous Media
… then react with the existing brine to generate carbonic acid. This process is defined as reactive flow and may lead to both dissolution and/or precipitation. Major effort has been invested in researching the former since it may induce significant structural changes in the formation and has …
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Adsorption–Desorption Reactions in the Weathering Zone: Implications for Silicate Weathering & the Carbon Cycle
The carbonic acid-driven chemical weathering of silicate minerals removes carbon dioxide (CO2) from Earth's atmosphere. The tectonic processes of uplift, exhumation, and erosion modulate the negative feedback relationship between climate, silicate weathering rates, and atmospheric CO2 removal rates …
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Ionization in H2O -- bearing carbon dioxide determined by conductivity measurements
Recent studies report rapid corrosion of metals and carbonation of minerals in contact with H2O-saturated (or nearly saturated) CO2. One explanation for this behavior is that addition of small amounts of H2O to CO2 leads to significant ionization within the fluid (analogous to corrosion in aqueous …
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Cerebral blood flow in the non-human primate : an in vivo model and drug interventions
… were included in the study were acetazolamide, a carbonic acid anhydrase inhibitor (often used in nuclear medicine to determine cerebral reserve); sumaptriptan, a 5-HT (serotonin) agonist used for treatment of migraine; sodium valproate (an anti-epileptic drug); nimodipine, a calcium channel …
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CO2-rock interaction during CO2-enriched brine injection into storage reservoirs using NMR integrated with fiber optic sensors
… rock samples. The injected CO2 produces a weak carbonic acid in the presence of formation water that can react with calcite within the rock causing ion dissolution and the formation of secondary minerals. This can in turn lead to significant changes in the geo-mechanical strength of the rock, …