Results 271 to 280 of about 3,531,989 (315)
Some of the next articles are maybe not open access.
1986
Extensive surface and groundwater monitoring programs have been installed throughout the country. When a chemical is detected in the discharge from a watershed, modeling is one approach to determine the reason for the presence of the chemical and to predict future trends in chemical levels.
George R. Oliver, W. Brock Neely
openaire +2 more sources
Extensive surface and groundwater monitoring programs have been installed throughout the country. When a chemical is detected in the discharge from a watershed, modeling is one approach to determine the reason for the presence of the chemical and to predict future trends in chemical levels.
George R. Oliver, W. Brock Neely
openaire +2 more sources
Chemical models for ribozyme action
Current Opinion in Chemical Biology, 2005Mechanistic studies of the action of catalytic ribonucleic acids, ribozymes, are highly challenging, because even a slight structural change can dramatically affect the chain folding. This, in turn, alters the binding properties of the catalytic core, making identification of the real origin of the observed influence on rate difficult.
Harri Lönnberg, Tuomas Lönnberg
openaire +3 more sources
A model for oscillating chemical reactions
Biophysical Chemistry, 1975A simple theoretical model for a class of oscillating chemical reactions is investigated, which is inspired by Degn's analysis of the mechanism of Belousov-Zhabotinsky reactions. Although the model involves only one auto-catalytic path, as distinct from models presented hitherto, a limit-cycle behaviour is found for the concentrations, corresponding to
Kazuhisa Tomita, Kazuo Kitahara
openaire +3 more sources
2017
Models of chemical structure play dual crucial roles in organic chemistry . First, they allow for the discovery and application of laws to the complex phenomena that chemists hope to understand. Second, they are a source of novel concepts that allow for the continuing development of structure theory and theoretical organic chemistry.
openaire +2 more sources
Models of chemical structure play dual crucial roles in organic chemistry . First, they allow for the discovery and application of laws to the complex phenomena that chemists hope to understand. Second, they are a source of novel concepts that allow for the continuing development of structure theory and theoretical organic chemistry.
openaire +2 more sources
Chemical models and radiation damage
Philosophical Transactions of the Royal Society of London. B, Biological Sciences, 1985E.s.r. spectroscopy has been used in conjunction with an aqueous flow system to investigate both the metal-catalysed decomposition of hydrogen peroxide to OH* and the subsequent reactions of this radical with a variety of biomolecules. Particular emphasis is placed on the effects of pH and ligand on the Fe II —H
M. Fitchett, Bruce C. Gilbert, M Jeff
openaire +3 more sources
Modelling in Chemical Dynamics
1988It would be interesting to trace the use of the expression “Chemical Dynamics” over the last twenty years. Today, it is used essentially by people working in the field of exotic behaviours of chemical reactions. Does it really imply something different from “Chemical Kinetics”?.
openaire +2 more sources
1997
When a chemical solution of uniform and time-independent concentration is introduced at the inlet of a filter, an initially sharp concentration front begins to migrate through the filter due to advection, and simultaneously spread due to diffusion.
openaire +2 more sources
When a chemical solution of uniform and time-independent concentration is introduced at the inlet of a filter, an initially sharp concentration front begins to migrate through the filter due to advection, and simultaneously spread due to diffusion.
openaire +2 more sources
Journal of Chemical Education, 2004
A simple model of the chemical bond is developed on the basis of an elementary MO theory requiring solution of at most a 2 × 2 Huckel secular equation including overlap. The fundamental quantities are the atomic integrals α1 and α2 giving the energies of the isolated atoms or ions, and the bond integral b which depends on the overlap S between the ...
openaire +2 more sources
A simple model of the chemical bond is developed on the basis of an elementary MO theory requiring solution of at most a 2 × 2 Huckel secular equation including overlap. The fundamental quantities are the atomic integrals α1 and α2 giving the energies of the isolated atoms or ions, and the bond integral b which depends on the overlap S between the ...
openaire +2 more sources
Comptes Rendus de l'Académie des Sciences - Series IIA - Earth and Planetary Science, 1999
Abstract This article presents a critical review of method, concepts and prejudices used bv modelists of the Earth's chemical composition over approximate the last fifty years and of the resulting compositions. Brief descriptions are given of admitted accretion mechanisms, of the starting materials most often considered and of the major parameters ...
openaire +2 more sources
Abstract This article presents a critical review of method, concepts and prejudices used bv modelists of the Earth's chemical composition over approximate the last fifty years and of the resulting compositions. Brief descriptions are given of admitted accretion mechanisms, of the starting materials most often considered and of the major parameters ...
openaire +2 more sources
Modeling Chemical Communication
Science Signaling, 2009In populations of single-celled organisms such as yeast, transitions can occur in their coordinated behavior that depend on their density in solution and that are believed to be triggered through chemical signaling. Taylor et al. modeled these transitions by studying large populations of chemical oscillators (about 100,000).
openaire +2 more sources