Results 261 to 270 of about 864,738 (314)

Sodium NMR relaxation in porous materials

Journal of Magnetic Resonance, 2004
The NMR relaxation of hydrogen nuclei of a fluid in a porous material is generally interpreted in terms of the Brownstein-Tarr model, in which the relaxation rate of the signal is inversely proportional to the pore size. We have investigated whether this model can be applied to the relaxation of Na nuclei in a NaCl solution in a porous material.
Pieter Magusin, K Kopinga, H P Huinink   +2 more
exaly   +3 more sources

NMR relaxation in cellulose pulp

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1996
Abstract 1 H NMR has been used to study water dynamics in cellulose pulp. The reduction of water NMR line width with an increase of moisture content was observed. Different temperature dependencies of spin-lattice relaxation time were obtained for different origins of cellulose.
Barbara Blicharska, Maciej Kluza
exaly   +2 more sources

NMR relaxation studies with MnDPDP

Acta Radiologica, 1997
Purpose: Our studies were designed to compare the efficacy of mangafodipir triso-dium (MnDPDP, Teslascan) as a tissue-specific MR agent with that of manganese chloride (MnCl 2 ), to compare the efficacy of different doses and rates of administration of MnDPDP, and to collect the data needed ...
T E, Southon, D, Grant, A, Bjørnerud, O M, Moen, B, Spilling, I, Martinsen, H, Refsum   +6 more
openaire   +2 more sources

Spectral Estimation of NMR Relaxation

Journal of Magnetic Resonance, 2000
In this paper, spectral estimation of NMR relaxation is constructed as an extension of Fourier Transform (FT) theory as it is practiced in NMR or MRI, where multidimensional FT theory is used. nD NMR strives to separate overlapping resonances, so the treatment given here deals primarily with monoexponential decay.
, Naugler, , Cushley
openaire   +2 more sources

Temperature Effect on NMR Surface Relaxation

SPE Annual Technical Conference and Exhibition, 2001
Abstract We present NMR relaxation experiments of water and oil confined in a series of calibrated porous media and natural rocks of different wettability, at various temperatures and magnetic fields. The longitudinal 1/T1 and transverse 1/T2 relaxation rates are interpreted with an original theoretical model which shows that the solid ...
S. Godefroy, M. Fleury, F. Deflandre, J.-P. Korb   +3 more
openaire   +1 more source

NMR relaxation and the orientational structure factor

Physical Review B, 1993
A class of NMR relaxation mechanisms is considered which is characterized by molecular reorientations mediated by translational displacements. This particularly refers to systems in which molecules are confined to disordered structures determining the local preferential orientations of the incorporated molecules and providing translational degrees of ...
, Kimmich, , Weber
openaire   +2 more sources

NMR Relaxation in Heterogeneous Systems

Nature, 1970
THERE has recently been some discussion1,2 of the difficulties of interpreting nuclear magnetic resonance line broadening in complex heterogeneous suspensions. The discussion has been concerned with hindered rotation of solvent species, and it has been confined to proton magnetic relaxation. We report here a study of the relaxation phenomenon in a well
openaire   +2 more sources

Relaxation times and NMR signals

Magnetic Resonance Imaging, 1984
The strength of signals in magnetic resonance imaging (and the resulting image contrast) depends not just on the number density of the nuclei being detected, but also on the relaxation times, T1 and T2. The relationship of signal strength to relaxation time depends on the particular choice of pulse sequences used to produce the signals.
openaire   +2 more sources

NMR Relaxation of Clay-Brine Mixtures

SPE Annual Technical Conference and Exhibition, 1998
Abstract Effective interpretation of nuclear magnetic resonance (NMR) logs in shaly sands requires an understanding of the NMR contribution of clays. Of particular importance is the role of clays in the rapidly relaxing part of the NMR signal.
A. Matteson, J.P. Tomanic, M.M. Herron, D.F. Allen, W.E. Kenyon   +4 more
openaire   +1 more source

NMR Relaxation Dispersion

The FASEB Journal, 2016
NMR relaxation dispersion experiments are used to characterize millisecond and microsecond motions and the role of these motions in regulation of protein tyrosine phosphatases (PTPs) In a pair of mechanistically indistinguishable PTPs with catalytic rates that vary by 50‐fold these experiments indicate that catalytic activity is regulated by the rate ...
openaire   +1 more source