scholarly journals The Motion of Ions Confined in a Molecular Channel

2021 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
David Antony Morton-Blake
Keyword(s):  
Molecular Channel

Complementary variational principles for free molecular channel flow

1979 ◽  
Vol 82 (3-4) ◽  
pp. 211-223 ◽  
Author(s):  
R. J. Cole
Keyword(s):  
Integral Equations ◽  
Channel Flow ◽  
Lower Bounds ◽  
Variational Principles ◽  
Transmission Probability ◽  
Numerical Calculations ◽  
Upper And Lower Bounds ◽  
Gas Flows ◽  
Rectangular Duct ◽  
Molecular Channel

SynopsisA collisionless gas flows through a finite rectangular duct which reflects molecules diffusely. The transmission probability Q of the duct involves the solution of a pair of coupled integral equations. Complementary variational principles have been employed which supply upper and lower bounds to Q. Numerical calculations have been made for a variety of duct shapes and compared, where appropriate, to those of other authors.

scholarly journals Signature of a conical intersection in the dissociative photoionization of formaldehyde

2020 ◽  
Vol 22 (23) ◽  
pp. 12886-12893
Author(s):  
Alexandre Zanchet ◽  
Gustavo A. García ◽  
Laurent Nahon ◽  
Luis Bañares ◽  
Sonia Marggi Poullain
Keyword(s):  
Ab Initio ◽  
Conical Intersection ◽  
Dissociative Photoionization ◽  
Molecular Channel

Electron/ion coincidence experiments and ab initio calculations of the dissociative photoionization of formaldehyde reveal the presence of a conical intersection controlling the dynamics and favoring dissociation into the molecular channel, CO+ + H2.

scholarly journals Pressure dependence of the deuterium isotope effect in the photolysis of formaldehyde by ultraviolet light

2010 ◽  
Vol 10 (7) ◽  
pp. 3455-3462 ◽  
Author(s):  
E. J. K. Nilsson ◽  
V. F. Andersen ◽  
H. Skov ◽  
M. S. Johnson
Keyword(s):  
Isotope Effect ◽  
Pressure Dependence ◽  
Kinetic Isotope Effect ◽  
Ambient Pressure ◽  
Deuterium Isotope Effect ◽  
Kinetic Isotope ◽  
Molecular Channel ◽  
The University ◽  
First Time ◽  
Gas Pressures

Abstract. The pressure dependence of the relative photolysis rate of HCHO vs. HCDO has been investigated for the first time, using a photochemical reactor at the University of Copenhagen. The dissociation of HCHO vs. HCDO using a UVA lamp was measured at total bath gas pressures of 50, 200, 400, 600 and 1030 mbar. The products of formaldehyde photodissociation are either H2 + CO (molecular channel) or HCO + H (radical channel), and a photolysis lamp was chosen to emit light at wavelengths that greatly favor the molecular channel. The isotope effect in the dissociation, kHCHO/kHCDO, was found to depend strongly on pressure, varying from 1.1 + 0.15/−0.1 at 50 mbar to 1.75±0.10 at 1030 mbar. The results can be corrected for radical channel contribution to yield the kinetic isotope effect for the molecular channel; i.e. the KIE in the production of molecular hydrogen. This is done and the results at 1030 mbar are discussed in relation to previous studies at ambient pressure. In the atmosphere the relative importance of the two product channels changes with altitude as a result of changes in pressure and actinic flux. The study demonstrates that the δD of photochemical hydrogen produced from formaldehyde will increase substantially as pressure decreases.

Molecular Ion Channels; Electrodiffusion in R3

2010 ◽  
Vol 297-301 ◽  
pp. 1469-1474 ◽  
Author(s):  
Bogusław Bożek ◽  
Bartek Wierzba ◽  
Marek Danielewski
Keyword(s):  
Ion Channels ◽  
Ion Transport ◽  
Quantitative Description ◽  
Three Dimensional ◽  
Radial Symmetry ◽  
Clear Understanding ◽  
Three Dimensional Model ◽  
Molecular Ion ◽  
Channel Interactions ◽  
Molecular Channel

Ion transport across the membrane of the living cell (molecular ion channels) is a critical process, e.g., the triggering of nerve cells and heart muscle cells is coupled with mechanisms controlled by ion diffusion (electrodiffusion). Although the process is described by the century old Nernst- Planck-Poisson system of equations, it is not well understood and a clear understanding of how the interaction between channel and ions affects the flow is still missing. We present a three-dimensional model of the molecular channel. An appropriate quantitative description of the ion transport process allows proper explanation of molecule channel interactions (e.g. the ions flow for a given concentration gradient should depend on the potential and other parameters describing the interaction, i.e. asymmetric transport). We show the simulation of the stationary electrodiffusion in the ion channel showing radial symmetry.

Cistulynes: Proton NMR and single-crystal x-ray evidence for structure and cation encapsulation in a rigid, molecular channel model system

1989 ◽  
Vol 30 (38) ◽  
pp. 5099-5102 ◽  
Author(s):  
Akio Nakano ◽  
Yi Li ◽  
Philippe Geoffroy ◽  
Minsook Kim ◽  
Jerry L. Atwood ◽  
...  
Keyword(s):  
Single Crystal ◽  
Channel Model ◽  
Proton Nmr ◽  
Model System ◽  
X Ray ◽  
Molecular Channel
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