Self-Diffusion Studies in CuBTC by PFG NMR and MD Simulations

2010 ◽  
Vol 114 (23) ◽  
pp. 10527-10534 ◽  
Author(s):  
M. Wehring ◽  
J. Gascon ◽  
D. Dubbeldam ◽  
F. Kapteijn ◽  
R. Q. Snurr ◽  
...  
Keyword(s):  
Md Simulations ◽  
Self Diffusion ◽  
Diffusion Studies ◽  
Pfg Nmr

PFG NMR self-diffusion studies of fluid transport and surface-to-volume ratios in sands

2001 ◽  
Vol 19 (3-4) ◽  
pp. 584
Author(s):  
F. Stallmach ◽  
C. Vogt ◽  
P. Galvosas ◽  
J. Kärger ◽  
N. Klitzsch
Keyword(s):  
Fluid Transport ◽  
Self Diffusion ◽  
Diffusion Studies ◽  
Pfg Nmr

Self-diffusion studies of pore fluids in unconsolidated sediments by PFG NMR

2002 ◽  
Vol 50 (4) ◽  
pp. 455-467 ◽  
Author(s):  
Corina Vogt ◽  
Petrik Galvosas ◽  
Norbert Klitzsch ◽  
Frank Stallmach
Keyword(s):  
Unconsolidated Sediments ◽  
Pore Fluids ◽  
Self Diffusion ◽  
Diffusion Studies ◽  
Pfg Nmr

1H NMR characterisation of the diffusional properties of methanogenic granular sludge

1999 ◽  
Vol 39 (7) ◽  
pp. 187-194 ◽  
Author(s):  
P. Lens ◽  
F. Vergeldt ◽  
G. Lettinga ◽  
H. Van As
Keyword(s):  
Diffusion Coefficient ◽  
Relaxation Time ◽  
Bacterial Cell ◽  
Granular Sludge ◽  
T2 Relaxation ◽  
Self Diffusion ◽  
Diffusion Analysis ◽  
S Matrix ◽  
Granular Matrix ◽  
Pfg Nmr

The diffusive properties of mesophilic methanogenic granular sludge have been studied using diffusion analysis by relaxation time separated pulsed field gradient nuclear magnetic resonance (DARTS PFG NMR) spectroscopy. NMR measurements were performed at 22°C with 10 ml granular sludge at a magnetic field strength of 0.5 T (20 MHz resonance frequency for protons). Spin-spin relaxation (T2) time measurements indicate that three 1H populations can be distinguished in methanogenic granular sludge beds, corresponding to water in three different environments. The T2 relaxation time measurements clearly differentiate the extragranular water (T2 ≈ 1000 ms) from the water present in the granular matrix (T2 = 40-100 ms) and bacterial cell associated water (T2 = 10-15 ms). Self-diffusion coefficient measurements at 22°C of the different 1H-water populations as the tracer show that methanogenic granular sludge does not contain one unique diffusion coefficient. The observed distribution of self-diffusion coefficients varies between 1.1 × 10−9 m2/s (bacterial cell associated water) and 2.1 × 10−9 m2/s (matrix associated water).

scholarly journals Water and Deuterium Oxide Permeability through Aquaporin 1: MD Predictions and Experimental Verification

2007 ◽  
Vol 130 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Artem B. Mamonov ◽  
Rob D. Coalson ◽  
Mark L. Zeidel ◽  
John C. Mathai
Keyword(s):  
Deuterium Oxide ◽  
Diffusion Constant ◽  
Structural Data ◽  
Md Simulations ◽  
Water Model ◽  
Aquaporin 1 ◽  
Self Diffusion ◽  
Osmotic Permeability ◽  
Protein Channels ◽  
And Diffusion

Determining the mechanisms of flux through protein channels requires a combination of structural data, permeability measurement, and molecular dynamics (MD) simulations. To further clarify the mechanism of flux through aquaporin 1 (AQP1), osmotic pf (cm3/s/pore) and diffusion pd (cm3/s/pore) permeability coefficients per pore of H2O and D2O in AQP1 were calculated using MD simulations. We then compared the simulation results with experimental measurements of the osmotic AQP1 permeabilities of H2O and D2O. In this manner we evaluated the ability of MD simulations to predict actual flux results. For the MD simulations, the force field parameters of the D2O model were reparameterized from the TIP3P water model to reproduce the experimentally observed difference in the bulk self diffusion constants of H2O vs. D2O. Two MD systems (one for each solvent) were constructed, each containing explicit palmitoyl-oleoyl-phosphatidyl-ethanolamine (POPE) phospholipid molecules, solvent, and AQP1. It was found that the calculated value of pf for D2O is ∼15% smaller than for H2O. Bovine AQP1 was reconstituted into palmitoyl-oleoyl-phosphatidylcholine (POPC) liposomes, and it was found that the measured macroscopic osmotic permeability coefficient Pf (cm/s) of D2O is ∼21% lower than for H2O. The combined computational and experimental results suggest that deuterium oxide permeability through AQP1 is similar to that of water. The slightly lower observed osmotic permeability of D2O compared to H2O in AQP1 is most likely due to the lower self diffusion constant of D2O.

On the Structure and Dynamics of Microemulsions Self-Diffusion Studies

1982 ◽  
pp. 115-129 ◽  
Author(s):  
B. Lindman ◽  
N. Kamenka ◽  
B. Brun ◽  
P. G. Nilsson
Keyword(s):  
Self Diffusion ◽  
Structure And Dynamics ◽  
Diffusion Studies

Surface self-diffusion studies on the (111) surface of vanadium

1983 ◽  
Vol 125 (2) ◽  
pp. 396-408 ◽  
Author(s):  
J.M. Yu ◽  
R. Trivedi
Keyword(s):  
Self Diffusion ◽  
Diffusion Studies
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