Results 11 to 20 of about 25,524 (29)
Assessing natural attenuation at field scale by stochastic reactive transport modelling [PDF]
, 2010 A combined integral measuring and modelling approach is presented and applied, to assess natural attenuation at the former gasworks site in Stuttgart, ´Testfeld Süd´. The approach copes with subsurface heterogeneity by two different means.
Peter, Anita
core
Speeding up reactive transport simulations in cement systems by surrogate geochemical modeling: deep neural networks and k-nearest neighbors [PDF]
arXiv, 2021 We accelerate reactive transport (RT) simulation by replacing the geochemical solver in the RT code by a surrogate model or emulator, considering either a trained deep neural network (DNN) or a k-nearest neighbor (kNN) regressor. We focus on 2D leaching of hardened cement paste under diffusive or advective-dispersive transport conditions, a solid ...
arxiv
Enabling Under-Ice Geochemical Observations with a Size, Weight, and Power-Constrained Robot [PDF]
arXiv, 2022 Estimates of greenhouse gas emissions from Arctic estuarine environments are dominated by in situ summer-time ice-free dissolved gas measurements due to the logistical ease of performing field observations in these conditions. Recent evidence in coastal Arctic environments, however, has demonstrated that dissolved methane (CH4) and carbon dioxide (CO2)
arxiv
Dynamical Geochemistry: Mantle dynamics and its role in the formation of geochemical heterogeneity [PDF]
arXiv, 2023 Chemical geodynamics is a term coined nearly forty years ago to highlight the important link between Earth's geochemical evolution and plate tectonics & mantle convection. Significant progress in our understanding of this connection has taken place since then through advances in the analytical precision of geochemical measurements, dramatically ...
arxiv
Estimating terrestrial uranium and thorium by antineutrino flux measurements [PDF]
PNAS 105 (2008) 44-47, 2008 Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth ...
arxiv +1 more source
An "archaeological" quest for galactic supernova neutrinos [PDF]
JCAP 0904:029,2009, 2009 We explore the possibility to observe the effects of electron neutrinos from past galactic supernovae, through a geochemical measurement of the amount of Technetium 97 produced by neutrino-induced reactions in a Molybdenum ore. The calculations we present take into account the recent advances in our knowledge of neutrino interactions, of neutrino ...
arxiv +1 more source
The Paleoclimatic evidence for Strongly Interacting Dark Matter Present in the Galactic Disk [PDF]
arXiv, 2016 Using a recent geochemical reconstruction of the Phanerozoic climate which exhibits a 32 Ma oscillation with a phase and the secondary modulation expected from the vertical the motion of the solar system perpendicular to the galactic plane (shaviv et al.
arxiv
Impact-induced Vaporization During Accretion of Planetary Bodies [PDF]
Giant impacts dominate the late stages of accretion of rocky planets. They contribute to the heating, melting, and sometimes vaporizing of the bodies involved in the impacts. Due to fractionation during melting and vaporization, planet-building impacts can significantly change the composition and geochemical signatures of rocky objects.
arxiv +1 more source
arXiv, 2017 Earth's atmosphere has evolved as volatile species cycle between the atmosphere, ocean, biomass and the solid Earth. The geochemical, biological and astrophysical processes that control atmospheric evolution are reviewed from an "Earth Systems" perspective, with a view not only to understanding the history of Earth, but also to generalizing to other ...
arxiv
Robust chemical solver for fully-implicit simulations [PDF]
arXiv, 2018 The study of geological systems requires the solution of complex geochemical relations. We present an implementation of a chemical solver which can handle various types of models, including surface chemistry. The implementation is done in view of easy coupling with flow simulations to obtain a fully-coupled, fully-implicit solver for chemical reaction ...
arxiv