Viscosity Correlations with Nuclear (Proton) Magnetic Resonance Relaxation in Oil Disperse Systems

2018 ◽  
Vol 49 (3) ◽  
pp. 309-325 ◽  
Author(s):  
R. S. Kashaev
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Disperse Systems ◽  
Oil Disperse Systems ◽  
Resonance Relaxation

A proton magnetic resonance relaxation study of molecular motions in trimethylamine-borane

1976 ◽  
Vol 54 (7) ◽  
pp. 1087-1091 ◽  
Author(s):  
T. T. Ang ◽  
B. A. Dunell
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Solid Phase ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Free Induction ◽  
Resonance Spin ◽  
Resonance Relaxation

Proton magnetic resonance spin–lattice relaxation times T1 have been measured for trimethylamine-borane from 120 to 380 K, a few degrees above the melting point. Minima in T1 at 157 and 259 K are attributed to threefold reorientation of each of the three methyl groups and the borane group and to threefold reorientation of the whole molecule about the B—N axis, respectively. Activation energies for these processes were found to be 3.3 and 6.7 kcal/mol. Abrupt changes in T1 at 350 and 360 K correspond exactly with heat capacity transitions observed by other workers. The time constant for the decay of the free induction signal (FID curve) changes by two orders of magnitude at 360 K. Having a value of some 3 ms above 360 K, it shows that there must be rapid diffusion as well as molecular tumbling in the highest temperature solid phase.

scholarly journals Thyroid Tissue Characterization by Proton Magnetic Resonance Relaxation Time Determination

1987 ◽  
Vol 26 (1) ◽  
pp. 27-32 ◽  
Author(s):  
J. Tennvall ◽  
M. Olsson ◽  
T. Möller ◽  
M. Åkerman ◽  
J. Ranstam ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Tissue Characterization ◽  
Thyroid Tissue ◽  
Time Determination ◽  
Resonance Relaxation

A proton magnetic resonance relaxation time study of several vitamin D derivatives

1980 ◽  
Vol 58 (1) ◽  
pp. 45-50 ◽  
Author(s):  
George Kotowycz ◽  
Tom T. Nakashima ◽  
M. Kirk Green ◽  
Gerdy H. M. Aarts
Keyword(s):  
Vitamin D ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Relaxation Times ◽  
Biologically Active ◽  
Resonance Relaxation ◽  
S Application ◽  
Calculated Distance ◽  
Spectral Assignment

Proton magnetic resonance relaxation time studies at 200 and 400 MHz have been measured for vitamins D2, D3, as well as the biologically active 1α,25-(OH)2D3. A comparison of these relaxation times at the two frequencies allows the evaluation of the dipolar correlation times for the different protons in the molecule. These are very short, and range from < 0.7 × 10−10 s to 1.2 × 10−10 s. Application of the Solomon equation to the relaxation times of the 19Z and 19E protons allows a calculation of the internuclear distance since these two geminal protons relax each other predominantly by the dipolar mechanism. Using the T1 values, the calculated distances are 1.98 ± 0.10 Å for 1α,25-(OH)2D3, 2.01 ± 0.10 Å for D3, and 1.95 ± 0.10 Å for D2. The calculated distance based on a neutron diffraction distance for the C—H bond is 1.91 Å. The measurement of the relaxation times also allows a definitive spectral assignment of the 21- and 28-methyl protons for vitamin D2.

Proton magnetic resonance relaxation in a series of dimethylsiloxane polymers

1961 ◽  
Vol 55 (161) ◽  
pp. 361-380 ◽  
Author(s):  
J. G. Powles ◽  
A. Hartland ◽  
J. A. E. Kail
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Resonance Relaxation
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