Factors spin speed

Fig. 11 (a) 2D NCO experiment with optimal control element inserted for 15N — 13C transfer. Transfer efficiencies for the ocNCO experiment optimized for 12 kHz spinning speed as function of (b) resonance offsets for 13C and 1SN and (c) rf inhomogeneity/adjustment in terms of scaling factors on the nominal rf field strengths for 13C and 15N. (d) Experimental ocNCO 2D spectrum of uniformly 13C,15N-labeled ubiquitin with the projections to the left comparing ocNCO experiment most intense) and DCP (less intense) based NCO experiments [reproduced with permission from [161] (a, d) and [164] (c)]... 

Experimentally, the average film thickness exhibits a power-law dependence on final spin speed (157). The relationship can be expressed approximately as d — kw °, in which d is the resulting film thickness, w is the final spin speed, k is a concentration-dependent front factor, and a is the power-law exponent. The power-law exponent a is strictly a function of starting solution composition. The dependence of a on solid content (and in cases in which the polymer molecular weight varies while the total solid... 

Notice that one can only measure the product pao with this technique. Notice also that the event rate at energy E depends on the WIMP velocity distribution at speeds v > ME/2p . This integration limit depends on the nuclear mass, and thus detectors with different kinds of nuclei are sensitive to different regions of the WIMP velocity space. Moreover, the cross section gq scales differently for spin-dependent and spin-independent WIMP-nucleus interactions. Finally, while there is a consensus on the spin-independent nuclear form factors, spin-dependent form factors are sensitive to detailed modeling of the proton and neutron wave functions inside the nucleus , seeand references therein] Jungman 1996. 

Sound basic information can be found in books. Books do a good job of furnishing information on the principles of the spinning, weaving, or mercerizing processes, for example. While the information on methods or such factors as speeds or concentrations may not be completely up to date, the principles are usually unchanged. 

Figure 28 shows the two-dimensional H- V HETCOR NMR spectra of poly(L-prolines) (A) PPI and (B) PPII. The solid-state H- C HETCOR NMR measurements were performed on a Bruker DSX 300 spectrometer operating at 300 MHz, equipped with a 4 mm CP-MAS probe. The pulse sequence proposed by Burum et alJ was utilized for HETCOR, and the BLEW-24 pulse sequence was used for homonuclear decoupling of H. The 7r/2 pulse width was 2.8 ps for both C and H under CP conditions. The spinning speed was set to 5.0 kHz. The H chemical shift using BLEW-24 was calculated with a scaling factor 0.29 for all samples, which is a reasonable value. 

The spinning speed is 800 m min, and the filaments are thus accelerated in the spin-line by a factor of 800/8.87 = 90. In practice this is viscous flow rather than molecular orientation. Calling this a draw ratio is misleading draft , drawdown or spin stretch factor are better notions. 

The crucial factor when increasing the spinning speed is the twist insertion. Ideally, the mechanically moved mass is reduced to a minimum. Pneumatic methods have hence come into focus in recent years. In addition to higher yarn speed, wear of machine components owing to friction is also expected to be reduced. At present, there are two machine manufacturers offering air-jet spinning machines, Murata (MVS process, introduced 2003, Japan) and Rieter (2011, Switzerland). 

Figure 9.9 shows the evolution of birefringence or orientation factor along the spinline at different spiiming speeds. The spimiing speed affects the development of molecular orientation. With increase in spinning speed, the molecnlar orientation develops at an earlier time and the maximnm orientation that can be developed in the spinline also is higher. 

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