Spinning suppression

Therefore, at this level (with spin suppressed) the time-reversal operator is just the complex conjugation operator. it which replaces i by —i. 

The spin lock removes signals from isolated I spins. Suppression of unwanted signals can approach that of gradient selection. 

Rapid solidification and inviscid melt spinning suppress crystallization, which would otherwise occur with aluminate and YAG melts which are derived from highly crystalline materials. Fibers from liquefied gases, fibers from inviscid melt spun oxides and ribbons from rapidly solidified metal alloy melts are amorphous. Fibers spun from inviscid metal melts are predominantly amorphous but contain a minor crystalline phase. 

A high voltage in electro-spinning suppressed the formation of a-crystals, and helped to form PLLA/PDLA fibers with predominately stereocomplex crystals. ... 

In electron spin echo relaxation studies, the two-pulse echo amplitude, as a fiinction of tire pulse separation time T, gives a measure of the phase memory relaxation time from which can be extracted if Jj-effects are taken into consideration. Problems may arise from spectral diflfrision due to incomplete excitation of the EPR spectrum. In this case some of the transverse magnetization may leak into adjacent parts of the spectrum that have not been excited by the MW pulses. Spectral diflfrision effects can be suppressed by using the Carr-Purcell-Meiboom-Gill pulse sequence, which is also well known in NMR. The experiment involves using a sequence of n-pulses separated by 2r and can be denoted as [7i/2-(x-7i-T-echo) J. A series of echoes separated by lx is generated and the decay in their amplitudes is characterized by Ty. ... 

Dimensional Stability. The wet heat resistance of PVA fiber is indicated by the wet softening temperature (WTS) at which the fiber shrinks to a specified ratio. At one time, the WTS was not more than 95°C for nonacetalized PVA fiber, but improvement of WTS has been achieved by improvement in heat-drawing and -treating techniques other methods proposed include suppression of polymerization temperature of vinyl acetate (36) and employment of alkafi spinning (37). 

Suppression of the tme diagonal peaks by double-quantum filtering (DQF-COSY) may resolve such problems. Finally, quantitative measurements of the magnitude of the coupling constants is possible using the Z-COSY modification, These experiments ate restricted to systems of abundant spins such as H, and which have reasonably narrow linewidths. 

ROESY Rotating frame NOESY, detection of NOE in the HH COSY format with suppressed spin-diffusion, detects closely spaced protons also in smaller molecules... 

The spin-echo is used to suppress the production of spurious signals due to field inhomogeneities or to eliminate errors in the setting of pulse widths. It is also possible to use the spin-echo to follow the decay of transverse magnetization and to determine the transverse relaxation time (7 2). How might we do this in practice ... 

The effectiveness of a crude oil demulsifier is correlated with the lowering of the shear viscosity and the dynamic tension gradient of the oil-water interface. The interfacial tension relaxation occurs faster with an effective demulsifier [1714]. Short relaxation times imply that interfacial tension gradients at slow film thinning are suppressed. Electron spin resonance experiments with labeled demulsifiers indicate that the demulsifiers form reverse micellelike clusters in the bulk oil [1275]. The slow unclustering of the demulsifier at the interface appears to be the rate-determining step in the tension relaxation process. 

The intense water signal and the broad protein resonances were suppressed by a combination of continuous secondary Irradiation at the water frequency and the Hahn spin-echo sequence (0[90 x-t-180 y-t-collect]). 

Soft-pulse multiple irradiation In this method, pre-saturation is done using shaped pulses having a broader excitation profile. Therefore, it is a more suitable method for the suppression of multiplets. This technique is very effective, easy to apply and easy to implement within most NMR experiments. In aqueous solutions, however, slowly exchanging protons would be detectable due to the occurrence of transfer of saturation. In addition, the spins with resonances close to the solvent frequency will also be saturated. 

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