TI relaxation time

Live oil with dissolved methane does not follow the above correlations as methane relaxes by a spin-rotation mechanism, even when dissolved in liquid hydrocarbons [13]. The Ti relaxation time as a function of rj/T is illustrated in Figure 3.6.2 for different gas/oil ratios expressed in units of m3 m-3 as a parameter. The solid line is the fit for zero gas/oil ratio and is given by Eq. (1). 

In CP MAS NMR studies of rhodopsin and their photoactivated state-metarhodopsin, Ahuja et al.70 have used the measurements of the Ti relaxation time. The Ti values measured for Cl8 (0.34 s for rhodopsin... 

A NMR study of water adsorbed on silica gel has been made by Zimmerman el al. 18). Transverse (Ta) and longitudinal (Ti) relaxation times of various amounts of water adsorbed at 25° have been obtained with the use of the spin-echo technique and a two-phase behavior of both Ta and T relaxation times has been observed as illustrated in Figs. 10a and b. Generally only one T value is obtained, as for a single phase, except for x/m g HaO/g solid) values in the vicinity ol x/m = 0.126. Two values of Ta... 

Figure 4.19 Temperature dependence of the dipolar Ti relaxation time in semi logarithmic coordinates at the Larmor frequency coq- The dashed T i curve corresponds to a higher Larmor frequency. The regions with and 1 <<0)qT ...

An interesting new experimental approach has been taken in order to separate overlapping EPR spectra as they appear e.g. in the multi Fe/S centre containing complex I. Inversion- and saturation-recovery measurements which allow to measure Ti relaxation times are used in a inversion-recovery filter which is subsequently applied to separate EPR signals on account of their Trdifferences. In addition, this filter can be used in conjunction with high-resolution hyperfine measurements e.g. by ESEEM and thus the separated centres can be characterized in depth.211... 

The temperature dependence of Ti relaxation times for filled PDMS containing 60 vol% of Aerosil is shown in Fig. 4 [21]. 

Satisfying these conditions results in large gains in sensitivity (approximately fourfold in C observed experiments) and much shorter relaxation times because the relaxation delay required by the sample is now governed by the Ti (spin-lattice relaxation time) rather than C Ti. Relaxation times for are much shorter than for C, so the number of transients one may acquire in a given amount of time is greatly... 

Analysis of the NMR parameters and the dynamic processes depends on the exchange rates. The basic one-dimensional band-shape analysis is best suited to intermediate rates (10—10 per s). Slow exchange rates (—0.1-10 per s) are most accurately measured by using magnetization transfer experiments and Ti-relaxation times. Fast dynamic processes (> 10 per s) can be elucidated by investigating the spin-spin relaxation times. 

Dynamics of nano- to picosecond proton transfer processes in the N labeled polycrystalline tetraaza[14]annulene have been studied by a combination of 9.1 MHz N Ti relaxation time measurements under CPMAS conditions and by 46 MHz H Ti relaxation time measurements of a static sample of a doubly deuterated sample. 

Fig. 2.2.8 Pulse sequences for measurement of Ti relaxation times by (a) saturation recovery and (b) inversion recovery. The effect of the pulse sequences is illustrated in terms of the vector model of the nuclear magnetization and by graphs showing the evolution of the longitudinal magnetization M, as a function of ti.

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