Water, proton spin-lattice

NMRD studies (0.01-30 MHz) on bentonite suspensions showed that the water-proton spin-lattice relaxation rates are dominated by magnetic interactions with paramagnetic centers entrapped in the mineral matrix (89). The 1/Ti values were linearly dependent on the concentration of the... 

Fig. 2. Water proton spin-lattice relaxation dispersion in Cab-O-Sil M- samples with two different degrees of compression. The solid lines were computed using the model as in Ref. (45).

Fig. 8. The water-proton spin-lattice relaxation rates vs. magnetic field strength plotted as the Larmor frequency at 282 K for hexacyanochromate(II) ion ( ), trioxalatochromate(III) ion ( ), and trimalonatochromate(III) ion (A). The lines were computed using translational diffusion models developed by Freed with and without the inclusion of electron spin relaxation effects 54,121).

Fig. 17. The water proton spin-lattice relaxation rates as a function of magnetic field strength reported as the proton Larmor frequency in aqueous 1.8 mM samples of bovine serum albumin. The lower data set was taken on the solution, the open circles taken after the sample had been cross-linked with glutaraldehyde to stop rotational motion (89).

Lauterbur PC, Mendoni a-Dias HM, Rudin AM (1978) Augmentation of tissue water proton spin-lattice relaxation by in vivo addition of paramagnetic ions. In Dutton PL, Leigh JS, Scarpa A (eds) Frontiers of Biological Energetics, vol 1. Academic, New York, pp... 

K. Krynicki 1966, (Proton spin-lattice relaxation in pure water between 0 °C and 100°C), Physica 32, 167-178. 

J. C. Hindman, A. Svirmickas, M. Wood 1973, (Relaxation processes in water. A study of the proton spin-lattice relaxation time),/. Chem. Phys. 59 (3), 1517— 1522. 

Fig. 1. Magnetic field dependences of the proton spin-lattice relaxation time of water in Bioran B30 and Vycor glasses at temperatures above 27°C and below the temperature where the non-surface water freezes ( —25°C and —35°C). The solid lines represent the power law in the Larmor frequency with an exponent of 0.67 (34).

The proton spin-lattice relaxation times for solvent water are strongly perturbed if the water is in rapid exchange with a paramagnet. In particular, Mn is a strong relaxer for water protons and thus nuclear magnetic resonance (NMR) spectroscopy provides a sensitive probe for the presence of exchangeable water molecules bound to Mn in Mn proteins. 

Figure 10. Proton spin lattice relaxation time dependence vs. temperature for different water contents (NMR, 60 MHz)...

The proton spin-lattice relaxation time, Tj, of water was measured using this probe as a function of pressure and temperature (see Fig. 4.30). ° The study focused on the supercritical region (above = 374 °C) where the spin-... 

Figure 6. The proton spin-lattice time, Tt, in water as a function of temperature and density (Ref. 11. The supercritical values are at temperatures greater than...

Godfioy et al. studied the dynamics and interaction of water bound to milk proteins (caseins) as a iimction of aging. A dry salted mozzareUa-style (pasta filata or hot-streched) and a gouda-style cheese were manufaetured for this project. The proton spin-lattice relaxation rate of the samples is described by a Power Low function in the Larmor Frequency. All the curves terminate in a plateau at low field and its relaxation rate is directly related to the degree of hydration of the protein that increases with ripening. 

To further probe the role of hydration water in the high-T crossover, we measure the NMR proton spin-lattice relaxation time constant Ti of the lysozyme-water system with h = 0.3 in the interval 275K < T < 355K (Fig. 3b). Figure 3b also shows T for pure bulk water. Note that the hydration water Ti is characterized by two contributions, one coming from the hydration water protons (on the order of seconds, as in bulk water, Tih) and the other from the protein protons (on the order of 10 ms Tip). Figure 3b also shows that, as T increases, the bulk water Ti follows the VFT law across the entire temperature range, but the Tn, exhibits two... 

Lynch, L.J., and Webster, D.S. Proton spin-lattice relaxation of water associated with brown coal. J. Magn. Reson. 1980 40 259-272. 

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