Measurement of Proton Relaxation Times with a High Resolution Nuclear Magnetic Resonance Spectrometer. Progressive Saturation Method.

1965 ◽  
Vol 37 (8) ◽  
pp. 979-983 ◽  
Author(s):  
A. L. Van Geet ◽  
D. N. Hume
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Relaxation Times ◽  
Proton Relaxation ◽  
Nuclear Magnetic Resonance Spectrometer ◽  
Saturation Method ◽  
Nuclear Magnetic

Low temperature nuclear magnetic resonance studies of NH4ClO4

1976 ◽  
Vol 54 (3) ◽  
pp. 239-251 ◽  
Author(s):  
R. F. Code ◽  
J. Higinbotham ◽  
A. R. Sharp
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Low Temperature ◽  
Relaxation Times ◽  
Ammonium Ion ◽  
Proton Relaxation ◽  
Spin Conversion ◽  
Type Symmetry ◽  
Symmetry Species ◽  
Nuclear Magnetic

The properties of ammonium perchlorate were investigated in the temperature range between 1.3 and 50 K by nuclear magnetic resonance and relaxation experiments. The observed increase in the proton second moment from its high temperature value of ~ 1.18 G2 to the value of 4.30 G2 below 4.2 K was associated with a characteristic activation energy of ~ 4 × 10−21 J molecule−1 (~ 0.6 kcal mole−1). No evidence could be found for nuclear spin conversion between the symmetry species of the ammonium ion from measurements of the static proton magnetic susceptibility above 1.3 K. An asymptotic analysis of the low temperature proton lineshapes identified the broad wings of the lines with ammonium ions of T type symmetry. Measurements of the proton relaxation times T1 and T1ρ agreed with previous work by others on NH4ClO4, and were similar to observations on other ammonium compounds having low reorientational barriers.

Some Recent Developments in High Resolution Nuclear Magnetic Resonance

1972 ◽  
Vol 26 (4) ◽  
pp. 421-430 ◽  
Author(s):  
Edwin D. Becker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Nuclear Overhauser Effect ◽  
Double Resonance ◽  
Relaxation Times ◽  
Nuclear Magnetic Resonance Spectra ◽  
Recent Developments ◽  
Nuclear Overhauser ◽  
Nuclear Magnetic

Techniques for studying high resolution nuclear magnetic resonance spectra have been considerably broadened in recent years. The most far reaching development—pulse Fourier transform (FT) methods—is discussed in detail. Applications of FT techniques to measurement of relaxation times and to enhancement of weak signals, especially from natural abundance 13C, are reviewed. Double resonance methods, particularly the nuclear Overhauser effect, and the use of lanthanide shift reagents are also covered in this “mini-review.”

Intra-erythrocytic sodium in uremic patients, as determined by "high-resolution" 23Na nuclear magnetic resonance.

1986 ◽  
Vol 32 (1) ◽  
pp. 104-107 ◽  
Author(s):  
J P Monti ◽  
P Gallice ◽  
A Crevat ◽  
M el Mehdi ◽  
C Durand ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Healthy Subjects ◽  
Relaxation Times ◽  
Shift Reagent ◽  
Intracellular Sodium ◽  
Biological Media ◽  
Uremic Patients ◽  
Nuclear Magnetic

Abstract The use of 23Na nuclear magnetic resonance with aqueous shift reagent has made it possible to determine intracellular sodium concentrations in living erythrocytes. We applied this technique to samples from 16 healthy subjects and 41 uremic patients. The results seem to show distinct populations among the latter. Classically, two different relaxation times are obtained for intracellular sodium in biological media, according to relaxation NMR theory. Some patients, however, exhibit abnormal results that cannot be accounted for by this theory.

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