T2, transverse relaxation time

Transverse relaxation time T2 Weight of liquid phase Wl... 

Transverse relaxation time t2 Weight of liquid phase l... 

The width W is related to the transverse relaxation time T2 by the expression... 

Fig. 3. The basic Hahn sequence for the measurement of the transverse relaxation time T2. Any precession motion characterized by the frequency v in the rotating frame is refocused. This precession may arise either from chemical shift or from Bq inhomogeneity (symbolized by the shaded area, which has been strongly reduced for visualization purposes owing to the fast decay of the fid, it should in fact extend to the whole circle).

Fig. 9 Transverse relaxations times T2 of the Rb NMR signals of the two coexisting phase states versus temperature in D-RADP-25 resulting from the fit of Eq. 3 to the 2D time frequency spectra. The solid lines are guide lines for the eye...

The spectrum obtained by FT of the whole train of decaying echoes consisfs of a series of spikelets separated by the frequency vcpMG = l/ra. The envelope of these sidebands is defined by the second-order quadrupolar CT lineshape under MAS. The linewidth of each spikelet is determined by the true transverse relaxation time (T2) of the material, which is a measure of the decay time of the amplitude of the echoes in the... 

The structure of hard gels is best elucidated using SAXS or SANS because the periods of the ordered structures are on the scale 10-100nm. In addition to tube inversion and rolling ball viscometry, which are sensitive to yield stress, the formation of a hard gel can be identified by other techniques. These include DSC (gelation is an endothermic process), NMR (via transverse relaxation time, T2, measurements), polarized light microscopy and rheometry. 

Table IV. Temperature variation in correlation time (T(.), secular linewidth, r(M, k), and transverse relaxation time (T2) for M = -h. The Larmor frequency o)o/2Tr = 9.3 GHz. For an explanation, see text.

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