Atmospheric chemistry of oxygenated mercury-containing compounds

2021 ◽  
Author(s):  
Sonia Taamalli ◽  
Florent Louis ◽  
Michal Pitonak ◽  
Ivan Cernusak ◽  
Theodore S Dibble
Keyword(s):  
Atmospheric Chemistry ◽  
Relativistic Effects ◽  
Adsorbed Water ◽  
Reduction Reaction ◽  
Basis Sets ◽  
Mercury Compounds ◽  
Oxidation Reduction ◽  
Environmental Surfaces ◽  
Temperature Dependences ◽  
First Time

<p>Mercury is transported globally through the atmosphere as atomic mercury, but mostly it is transferred from the atmosphere to ecosystems in the form of Hg(II) compounds. As a result, scientists are increasingly focused on oxidation-reduction chemistry of mercury in the atmosphere. At present, little is known about the interaction of mercury compounds with environmental surfaces, which commonly possess adsorbed water.</p><p>As a first step towards understanding these interactions, we have theoretically studied the reaction of BrHgO• + CO → BrHg• + CO<sub>2</sub>, which constitutes a potentially important mercury reduction reaction in the atmosphere. We characterized the potential energy surface with CCSD(T)/CBS energies (with corrections for relativistic effects) at MP2 geometries. Master Equation simulations were used to reveal the factors controlling the overall rate constant.</p><p>In a second step and for the first time, the monohydration of several oxygenated mercury-containing compounds (BrHgO, BrHgOH, BrHgOOH, BrHgNO<sub>2</sub> and its isomers, and HgOH) with one water molecule has been theoretically studied using the ωB97X-D/aug‐cc‐pVTZ level of theory. The thermodynamic properties of the hydration reactions have been calculated using DFT geometries with energies with coupled-cluster calculations DK-CCSD(T) and the ANO‐RCC‐Large basis sets. Standard reaction enthalpy and standard Gibbs free reaction energy were computed. The temperature dependences of Δ<sub>r</sub>G°(T) were evaluated for all studied aggregates over the temperature range 200 - 400 K. For the first time, the monohydration processes have been studied to elucidate the role of hydrating water molecules. Atmospheric implications have been discussed.</p>

Introduction to Relativistic Quantum Chemistry

2007 ◽  
Author(s):  
Kenneth G. Dyall ◽  
Knut Faegri
Keyword(s):  
Dirac Equation ◽  
Quantum Chemistry ◽  
Relativistic Theory ◽  
Density Functional ◽  
Relativistic Quantum ◽  
Relativistic Effects ◽  
Basis Sets ◽  
Spin Orbit ◽  
Approximate Methods ◽  
Nonrelativistic Theory

This book provides an introduction to the essentials of relativistic effects in quantum chemistry, and a reference work that collects all the major developments in this field. It is designed for the graduate student and the computational chemist with a good background in nonrelativistic theory. In addition to explaining the necessary theory in detail, at a level that the non-expert and the student should readily be able to follow, the book discusses the implementation of the theory and practicalities of its use in calculations. After a brief introduction to classical relativity and electromagnetism, the Dirac equation is presented, and its symmetry, atomic solutions, and interpretation are explored. Four-component molecular methods are then developed: self-consistent field theory and the use of basis sets, double-group and time-reversal symmetry, correlation methods, molecular properties, and an overview of relativistic density functional theory. The emphases in this section are on the basics of relativistic theory and how relativistic theory differs from nonrelativistic theory. Approximate methods are treated next, starting with spin separation in the Dirac equation, and proceeding to the Foldy-Wouthuysen, Douglas-Kroll, and related transformations, Breit-Pauli and direct perturbation theory, regular approximations, matrix approximations, and pseudopotential and model potential methods. For each of these approximations, one-electron operators and many-electron methods are developed, spin-free and spin-orbit operators are presented, and the calculation of electric and magnetic properties is discussed. The treatment of spin-orbit effects with correlation rounds off the presentation of approximate methods. The book concludes with a discussion of the qualitative changes in the picture of structure and bonding that arise from the inclusion of relativity.

Pseudomonas aeruginosa transition from environmental generalist to human pathogen

2021 ◽  
Vol 13 (1) ◽  
pp. 11
Author(s):  
Gabriela Vasco ◽  
Gabriel Trueba
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Human Body ◽  
Biofilm Formation ◽  
Reduction Reaction ◽  
Human Pathogen ◽  
Opportunistic Bacteria ◽  
Oxidation Reduction ◽  
Mammalian Tissues ◽  
Oxidation Reduction Reaction ◽  
Source Sink

Opportunistic bacteria Pseudomonas aeruginosa is one of the major concerns as an etiological agent of nosocomial infections in humans. Many virulence factors used to colonize the human body are the same as those used by P. aeruginosa to thrive in the environment such as membrane transport, biofilm formation, oxidation/reduction reaction, among others. P. aeruginosa origin is mainly from the environment, the adaptation to mammalian tissues may follow a source-sink evolution model; the environment is the source of many lineages, some of them capable of adaptation to the human body. Some lineages may adapt to humans and go through reductive evolution in which some genes are lost.  The understanding of this process may be critical to implement better methods to control outbreaks in hospitals.

scholarly journals The Physical and Thermodynamic Functions of Borides

2017 ◽  
Vol 18 (1) ◽  
pp. 58-63
Author(s):  
N.Yu. Filonenko
Keyword(s):  
Free Energy ◽  
Physical Properties ◽  
Thermodynamic Functions ◽  
Point Of View ◽  
Energy Potential ◽  
High Temperature Expansion ◽  
Temperature Dependences ◽  
Function Calculation ◽  
First Time ◽  
Good Agreement

In the paper the physical properties and thermodynamic functions of borides Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr) are studied with accounting for fluctuation processes. We use the microstructure analysis, the X-ray structural and the durometric analyses to determine the physical properties of alloys. In the paper it is determined the phase composition and physical properties of borides. In this paper for the first time it is determined the thermodynamic functions of borides using the Hillert and Staffansson model with accounting for the first degree approximation of high-temperature expansion for the free energy potential of binary alloys. We obtain the temperature dependences for such thermodynamic functions as Gibbs free energy, entropy, enthalpy and heat capacity Ср along with their values at the formation temperature for Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr). The approach under consideration enables to give more thorough from the thermodynamic point of view description of borides formed from the liquid. The outcomes of the thermodynamic function calculation for borides are in good agreement with experimental data and results of other authors.

An Investigation on the Fine Structure Levels in the Ground State Configuration for the Antimony Anion

2014 ◽  
Vol 69 (8-9) ◽  
pp. 397-402
Author(s):  
Leyla Özdemir ◽  
Sadiye Tuna
Keyword(s):  
Fine Structure ◽  
Ground State ◽  
Transition Probabilities ◽  
Relativistic Effects ◽  
Electric Quadrupole ◽  
Radiative Transition ◽  
Ground State Configuration ◽  
Hartree Fock ◽  
First Time ◽  
State Configuration

We have investigated the correlation, relativistic, and isotope shift effects on the fine structure levels in the ground state configuration for the antimony anion ( Sb-). Energies and radiative transition probabilities (for magnetic dipole, M1, and electric quadrupole, E2) have been obtained using the multiconfiguration Hartree-Fock method within the framework of the Breit-Pauli Hamiltonian. Therefore, the most important configuration interaction and relativistic effects have been included. Comparisons with other available works are presented. For some M1 and E2 lines the considered transition probabilities are reported for the first time

The Oxidation-reduction Reaction of Quinoxaline-2- and 1,5-Naphthyridine-2-aldehyde N-Oxides and Their Hydrates

Heterocycles ◽  
1978 ◽  
Vol 9 (10) ◽  
pp. 1514
Author(s):  
A. S. Elina ◽  
I. S. Musatova ◽  
R. M. Titkova ◽  
E. A. Trifonova
Keyword(s):  
Reduction Reaction ◽  
Oxidation Reduction ◽  
Oxidation Reduction Reaction

scholarly journals Oxygen isotopic ratios in Martian water vapour observed by ACS MIR on board the ExoMars Trace Gas Orbiter

2019 ◽  
Vol 630 ◽  
pp. A91 ◽  
Author(s):  
J. Alday ◽  
C. F. Wilson ◽  
P. G. J. Irwin ◽  
K. S. Olsen ◽  
L. Baggio ◽  
...  
Keyword(s):  
Water Vapour ◽  
Atmospheric Chemistry ◽  
Trace Gas ◽  
Oxygen Isotope Ratios ◽  
Infrared Measurements ◽  
History Of ◽  
Oxygen Isotopic ◽  
Atmospheric Loss ◽  
The Impact ◽  
First Time

Oxygen isotope ratios provide important constraints on the history of the Martian volatile system, revealing the impact of several processes that might fractionate them, such as atmospheric loss into space or interaction with the surface. We report infrared measurements of the Martian atmosphere obtained with the mid-infrared channel (MIR) of the Atmospheric Chemistry Suite (ACS), onboard the ExoMars Trace Gas Orbiter. Absorption lines of the three main oxygen isotopologues of water vapour (H216O, H218O, and H217O) observed in the transmission spectra allow, for the first time, the measurement of vertical profiles of the 18O/16O and 17O/16O ratios in atmospheric water vapour. The observed ratios are enriched with respect to Earth-like values (δ18O = 200 ± 80‰ and δ17O = 230 ± 110‰ corresponding to the Vienna Standard Mean Ocean Water). The vertical structure of these ratios does not appear to show significant evidence of altitudinal variations.

CeO2 doped Pt/C as an efficient cathode catalyst for an air-cathode single-chamber microbial fuel cell

RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25877-25881 ◽  
Author(s):  
Ling Li ◽  
Mingkun Wang ◽  
Ning Cui ◽  
Yuedi Ding ◽  
Qingling Feng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Microbial Fuel Cell ◽  
Reduction Reaction ◽  
Cathode Catalyst ◽  
Air Cathode ◽  
Single Chamber ◽  
Cathode Catalysts ◽  
First Time

Incorporation of nanophase ceria into the cathode catalyst Pt/C was used as alternative cathode catalysts for the oxygen reduction reaction in an air-cathode single-chamber microbial fuel cell (SCMFC) for the first time.

Synthesis of monolayer platinum nanosheets

2014 ◽  
Vol 50 (62) ◽  
pp. 8503-8506 ◽  
Author(s):  
A. Funatsu ◽  
H. Tateishi ◽  
K. Hatakeyama ◽  
Y. Fukunaga ◽  
T. Taniguchi ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Platinum Oxide ◽  
Reduction Reaction ◽  
Highly Active ◽  
First Time

Platinum (Pt) nanosheets were developed by exfoliating layered platinum oxide. Moreover, we succeeded in synthesizing monolayer Pt nanosheets for the first time by adjusting the conditions for reduction. Monolayer Pt nanosheets were highly active in oxygen reduction reaction.

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