Application of two-dimensional NMR to kinetics of chemical exchange

1990 ◽  
Vol 90 (6) ◽  
pp. 935-967 ◽  
Author(s):  
Charles L. Perrin ◽  
Tammy J. Dwyer
Keyword(s):  
Chemical Exchange ◽  
Two Dimensional ◽  
Kinetics Of

Temperature Effect on the Two-Dimensional Phase Transition Kinetics of Adenine Adsorbed at the Hg Electrode/Aqueous Solution Interface

2003 ◽  
Vol 68 (8) ◽  
pp. 1407-1419 ◽  
Author(s):  
Claudio Fontanesi ◽  
Roberto Andreoli ◽  
Luca Benedetti ◽  
Roberto Giovanardi ◽  
Paolo Ferrarini
Keyword(s):  
Phase Transition ◽  
Aqueous Solution ◽  
Phase Change ◽  
Temperature Effect ◽  
Transition Rate ◽  
Effect Of Temperature ◽  
Two Dimensional ◽  
Solution Interface ◽  
Phase Transition Kinetics ◽  
Kinetics Of

The kinetics of the liquid-like → solid-like 2D phase transition of adenine adsorbed at the Hg/aqueous solution interface is studied. Attention is focused on the effect of temperature on the rate of phase change; an increase in temperature is found to cause a decrease of transition rate.

scholarly journals Two-dimensional numerical modeling of chemical transport–transformation in fluvial rivers: formulation of equations and physical interpretation

2009 ◽  
Vol 11 (2) ◽  
pp. 106-118 ◽  
Author(s):  
Sui Liang Huang
Keyword(s):  
Sediment Transport ◽  
Chemical Transport ◽  
Transformation Model ◽  
Diffusion Equations ◽  
Desorption Kinetics ◽  
Two Dimensional ◽  
Transformation Equation ◽  
Governing Equations ◽  
Convection Diffusion ◽  
Kinetics Of

Based on previous work on the transport–transformation model of heavy metal pollutants in fluvial rivers, this paper presents the formulation of a two-dimensional model to describe chemical transport–transformation in fluvial rivers by considering basic principles of environmental chemistry, hydraulics and mechanics of sediment transport and recent developments along with three very simplified test cases. The model consists of water flow governing equations, sediment transport governing equations, transport–transformation equation of chemicals and convection–diffusion equations of sorption–desorption kinetics of particulate chemical concentrations on suspended load, bed load and bed sediment. The chemical transport–transformation equation is basically a mass balance equation. It demonstrates how sediment transport affects transport–transformation of chemicals in fluvial rivers. The convection–diffusion equations of sorption–desorption kinetics of chemicals, being an extension of batch reactor experimental results, take both physical transport, i.e. convection and diffusion, and chemical reactions, i.e. sorption–desorption into account. The effects of sediment transport on chemical transport–transformation were clarified through three simple examples. Specifically, the transport–transformation of chemicals in a steady, uniform and equilibrium sediment-laden flow was calculated by applying this model, and results were shown to be rational. Both theoretical analysis and numerical simulation indicated that the transport–transformation of chemicals in sediment-laden flows with a clay-enriched riverbed possesses not only the generality of common tracer pollutants, but also characteristics of transport–transformation induced by sediment motion. Future work will be conducted to present the validation/application of the model with available data.

Ordering kinetics of two-dimensional O(2) models: Scaling and temperature dependence

1995 ◽  
Vol 52 (2) ◽  
pp. 1550-1557 ◽  
Author(s):  
Jong-Rim Lee ◽  
Sung Jong Lee ◽  
Bongsoo Kim
Keyword(s):  
Temperature Dependence ◽  
Two Dimensional ◽  
Ordering Kinetics ◽  
Kinetics Of

Recent 31 P n.m.r. studies of myocardium

1980 ◽  
Vol 289 (1037) ◽  
pp. 437-439 ◽  
Keyword(s):  
Mechanical Performance ◽  
Normal Values ◽  
Chemical Exchange ◽  
Exchange Reactions ◽  
Perfused Heart ◽  
Time Intervals ◽  
Non Invasive ◽  
Biochemical State ◽  
Perfused Hearts ◽  
Kinetics Of

Earlier work from this laboratory has concerned the possible use of phosphorus n.m.r. as a method to monitor, in a non-invasive manner, the biochemical state of the perfused heart as a function of its mechanical performance. We showed that a simulated coronary infarction could be detected by 31 P n.m.r. (Hollis et al 1978 a and that hypothermia and KC1 arrest could preserve the pH and the ATP levels at more nearly normal values than in a non-arrested heart during long periods (40 min) of ischaemia (Hollis et al . 1978 b ).More recently it was shown that multiple doses of KC1, given at intervals, were more effective in this respect than was a single dose (Flaherty et al . 1979). These studies essentially followed the kinetics of transitions of the heart between two or more distinct physiological states (i.e. normoxic and ischaemic, with or without KC1 arrest) by observation of the 31 P n.m.r. spectra at various time intervals over periods of up to 1 h. As described in detail and demonstrated in Dr Truman Brown’s contribution to these discussions, the rates of chemical exchange reactions occurring in a steady state can be measured by the techniques of saturation transfer in various biological systems, including perfused hearts.

Cobalt-assisted recrystallization and alignment of pure and doped graphene

Nanoscale ◽  
2018 ◽  
Vol 10 (25) ◽  
pp. 12123-12132 ◽  
Author(s):  
Dmitry Yu. Usachov ◽  
Kirill A. Bokai ◽  
Dmitry E. Marchenko ◽  
Alexander V. Fedorov ◽  
Viktor O. Shevelev ◽  
...  
Keyword(s):  
Underlying Mechanism ◽  
Two Dimensional ◽  
Doped Graphene ◽  
Kinetics Of

We convert polycrystalline graphene into monocrystalline graphene, and explore the kinetics of two-dimensional recrystallization as well as the underlying mechanism.

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