Preprints

Filtering by Subject: Chemistry

Carbonate clumped isotope analysis (Δ47) of 21 carbonate standards determined via gas source isotope ratio mass spectrometry on four instrumental configurations using carbonate-based standardization and multi-year datasets

Deepshikha Upadhyay, Jamie Lucarelli, Alexandrea Arnold, Randy Flores, Hayley Bricker, Robert Ulrich, Gregory Jesmok, William Defliese, Robert Eagle, Hannah Carroll, Jesse Bateman, Victoria Petryshyn, Sean Loyd, Jianwu Tang, Antra Priyadarshi, Ben Elliott, Aradhna Tripati

Published: 2020-11-28
Subjects: Chemistry, Earth Sciences, Physical Sciences and Mathematics

Rationale: Clumped isotope geochemistry examines the pairing or clumping of rare, heavy isotopes in molecules and provides information about the thermodynamic and kinetic controls on their formation. Since clumped isotope measurements of carbonate minerals were first published 15 years ago, interlaboratory offsets in calibrations have been observed, and laboratory and community practices for [...]

Sedimentary structures discriminations with hyperspectral imaging on sediment cores

Kévin Jacq, Rapuc William, Benoit Alexandre, Coquin Didier, Fanget Bernard, Yves Perrette, Pierre Sabatier, Wilhelm Bruno, Debret Maxime, Fabien Arnaud

Published: 2020-07-17
Subjects: Analytical Chemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Multivariate Analysis, Optics, Physical Sciences and Mathematics, Physics, Sedimentology, Statistical Models, Statistics and Probability

Hyperspectral imaging (HSI) is a non-destructive high-resolution sensor, which is currently under significant development to analyze geological areas with remote devices or natural samples in a laboratory. In both cases, the hyperspectral image provides several sedimentary structures that need to be separated to temporally and spatially describe the sample. Sediment sequences are composed of [...]

Forecasting the localized bilateral effects of ocean acidification on the counter carbonate pump using recurrent neural networks

Eshan Ramesh

Published: 2020-07-08
Subjects: Artificial Intelligence and Robotics, Chemistry, Computer Sciences, Environmental Chemistry, Numerical Analysis and Scientific Computing, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

The counter carbonate pump(CCP) is responsible for carbon dioxide sequestration and cycling forms of carbon in the ocean. It is primarily driven by calcifying plankton, such as foraminifera, coccolithophores, and pteropods. These organisms are particularly vulnerable to ocean acidification, which can have disastrous effects on their skeletons and productivity, upsetting the marine carbon cycle in [...]

Toward stable, general machine-learned models of the atmospheric chemical system

Makoto Kelp, Daniel J. Jacob, J. Nathan Kutz, Julian D. Marshall, Christopher W. Tessum

Published: 2020-03-23
Subjects: Artificial Intelligence and Robotics, Chemistry, Computer Sciences, Earth Sciences, Environmental Chemistry, Environmental Sciences, Physical Sciences and Mathematics

Atmospheric chemistry models—used as components in models that simulate air pollution and climate change—are computationally expensive. Previous studies have shown that machine-learned atmospheric chemical solvers can be orders of magnitude faster than traditional integration methods but tend to suffer from numerical instability. Here, we present a modeling framework that reduces error [...]

Fate of adsorbed organic compounds during transformation of ferrihydrite: implications for biogenic origin of Precambrian iron formations

Stanislav Jelavic, Andrew Mitchell, Karina Krarup Sand

Published: 2020-01-30
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Physical Chemistry, Physical Sciences and Mathematics

The absence of organic compounds from Precambrian iron formations (IF) challenges the hypothesis of their biogenic origin. Here we address the fate of adsorbed organic compounds during transformation from ferrihydrite to hematite. We determined the binding energy between hematite and common molecular terminations found in extracellular polymeric substances and biofilms: carboxylic, alcohol and [...]

Notes on the creation and manipulation of solid solution models

Robert Myhill, James Connolly

Published: 2019-12-04
Subjects: Chemistry, Earth Sciences, Materials Chemistry, Mineral Physics, Physical Sciences and Mathematics

A large class of solid solution models are built on the premise that exchange of chemical species takes place on a finite number of unique sites, and that the thermodynamic properties of the solution are a function of the proportions of species occupying each of the sites. The site-occupancy spaces spanned by such models are geometrically equivalent to convex polytopes, n-dimensional [...]

Pre-deliquescent water uptake in deposited nanoparticles observed with in situ ambient pressure X-ray photoelectron spectroscopy

Jack Jie Lin, Kamal Raj R, Stella Wang, Esko Kokkonen, Mikko-Heikki Mikkelä, Samuli Urpelainen, Nønne L. Prisle

Published: 2019-10-31
Subjects: Atmospheric Sciences, Chemistry, Oceanography and Atmospheric Sciences and Meteorology, Physical Chemistry, Physical Sciences and Mathematics

In this work we study the adsorption, or uptake, of water onto deposited inorganic sodium chloride and organic malonic acid and sucrose nanoparticles at low relative humidities from 0 to 16%. We employ the surface sensitive ambient pressure x-ray photoelectron spectroscopy technique, which has a detection sensitivity from parts per thousand. Our results show that water is adsorbed on sodium [...]

On the difficulties of being rigorous in environmental geochemistry studies: some recommendations for designing an impactful paper

Olivier Pourret, BOLLINGER Jean-Claude, Eric D. van Hullebusch

Published: 2019-10-25
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Geochemistry, Other Environmental Sciences, Physical Sciences and Mathematics

There have been numerous environmental geochemistry studies using chemical, geological, ecological and toxicological methods but each of these fields requires more subject specialist rigour than has generally been applied so far. Field-specific terminology has been misused and the resulting interpretations rendered inaccurate. In this paper, we propose a series of suggestions, based on our [...]

Probing the chemical transformation of seawater-soluble crude oil components during microbial oxidation

Yina Liu, Helen White, Rachel Simister, David Waite, Shelby Lyons, Elizabeth Kujawinski

Published: 2019-06-18
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Life Sciences, Microbiology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics

Studies assessing the environmental impacts of oil spills focus primarily on the non-water-soluble components, leaving the fate of the water-soluble fraction (WSF) largely unexplored. We employed untargeted chemical analysis along with biological information to probe the transformation of crude oil WSF in seawater, in the absence of light, in a laboratory experiment. Over a 14-day incubation, [...]

Effect of solution chemistry on the iodine release from iodoapatite in aqueous environments

ZELONG ZHANG, Léa Gustin, Weiwei Xie, Jie Lian, Kalliat T. Valsaraj, Jianwei Wang

Published: 2019-05-24
Subjects: Chemistry, Earth Sciences, Geochemistry, Materials Chemistry, Physical Sciences and Mathematics

To ensure the safe disposal of nuclear waste, understanding the release process of radionuclides retained in the nuclear waste forms is of vital importance. Iodoapatite Pb9.85(VO4)6I1.7, a potential waste form for iodine-129, was selected as a model system for ceramic waste forms in this study to understand the effect of aqueous species on iodine release. Semi-dynamic leaching tests were [...]

High-resolution prediction of organic matter concentration with hyperspectral imaging on a sediment core

Kévin Jacq, Yves Perrette, Fanget Bernard, Pierre Sabatier, Coquin Didier, Martinez-Lamas Ruth, Debret Maxime, Arnaud Fabien

Published: 2019-02-21
Subjects: Analytical Chemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Optics, Physical Sciences and Mathematics, Physics, Sedimentology, Statistical Models, Statistics and Probability

In the case of environmental samples, the use of a chemometrics-based prediction model is highly challenging because of the difficulty in experimentally creating a well-ranged reference sample set. In this study, we present a methodology using short wave infrared hyperspectral imaging to create a partial least squares regression model on a cored sediment sample. It was applied to a sediment core [...]

PREPRINT- Adsorption behavior of new theophylline-triazole based derivatives as effective corrosion inhibitors for steel in acidic medium

Araceli Espinoza-Vázquez, Francisco Javier Rodríguez-Gómez, Ivonne Karina Martínez-Cruz, Deyanira Ángeles Beltrán, Guillermo Enrique Negrón Silva, Manuel Eduardo Palomar Pardavé, Leticia Lomas Romero, Diego Pérez Martínez, Alejandra M. Navarrete-López

Published: 2019-02-18
Subjects: Chemistry, Other Chemistry, Physical Sciences and Mathematics

The design and synthesis of a series of theophylline derivatives containing 1,2,3-triazole moieties is presented. The corrosion inhibition activities of these new triazole-theophylline compounds were evaluated by studying the corrosion of API 5L X52 steel in 1 M HCl media. The results showed that an increase in the concentration of the theophylline-triazole derivatives also increases the charge [...]

POSTPRINT-Adsorption and corrosion inhibition behavior of new theophylline-triazole based derivatives for steel in acidic medium

Araceli Espinoza-Vázquez, Francisco Javier Rodríguez-Gómez, Ivonne Karina Martínez-Cruz, Deyanira Ángeles Beltrán, Guillermo Enrique Negrón Silva, Manuel Eduardo Palomar Pardavé, Leticia Lomas Romero, Diego Pérez Martínez, Alejandra M. Navarrete-López

Published: 2019-02-11
Subjects: Chemistry, Other Chemistry, Physical Sciences and Mathematics

The design and synthesis of a series of theophylline derivatives containing 1,2,3-triazole moieties is presented. The corrosion inhibition activities of these new triazole-theophylline compounds were evaluated by studying the corrosion of API 5L X52 steel in 1 M HCl media. The results showed that an increase in the concentration of the theophylline-triazole derivatives also increases the charge [...]

Insights into agricultural influences and weathering processes from major ion patters

Robert van Geldern, Peter Schulte, Michael Mader, Alfons Baier, Tobias Juhlke, Johannes Barth, Kern Lee

Published: 2018-06-04
Subjects: Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics, Water Resource Management

Karst areas and their catchments pose a great challenge for protection because fast conduit flow results in low natural attenuation of anthropogenic contaminants. Studies of the hydrochemistry of karst sources and river solutes are an important tool for securing and managing water resources. A study of the geochemical downriver evolution of the Wiesent River and its tributaries, located in a [...]

What caused Earths largest mass extinction event? New evidence from the Permian-Triassic boundary in northeastern Utah

Benjamin Burger

Published: 2018-02-26
Subjects: Biogeochemistry, Biology, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Indicators and Impact Assessment, Environmental Sciences, Geology, Life Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology

The discovery of a Permian-Triassic boundary section in northeastern Utah reveals a detailed record of events that led to one of the greatest mass extinctions on the planet. From 83% to 97% of the species living on the planet went extinct during this relatively short interval of geological time, which defines the major geological boundary between the Paleozoic and Mesozoic Eras. The cause and [...]

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