Order splits, measuring

Note any obvious splitting of the absorptions in the table (e.g. doublet, triplet, quartet, etc.). For spectra which appear to show first-order splitting, the coupling constants of each multiplet should be determined by measuring the separation between adjacent peaks in the multiplet. Any other recognisable patterns which are not first order should be noted. 

It differs from ordinary optical spectroscopy in that the energies of the y-photons involved are some 101 times greater than optical photon energies, and the order of magnitude of the energy-level splittings measured is some 108 times smaller. A schematic comparison of Mossbauer and IR spectroscopy is given in Table I. 

The lateral pressure concept provides useful insight into the spatial distribution of forces and is a sum over terms corresponding to layers of finite thickness (dz). Quantitative measurements of the LP remain difficult and even the concept has been criticized. Chain order parameters, measured by H-NMR studies on amphiphiles with specifically deuterium-labelled methylene units in the tails, ° gave a similar view of the distribution of the chain attractions/repulsions as a function of position in the tails. Increasing quad-rupole splittings, indicated by an increasing distance between the two peaks in the H-NMR spectrum, are associated with increasing chain order. 

Fig. 5.2.8. Temperature dependence of the orientational order parameter s determined by quadrupolar splitting measurements for CBOOA. The inset shows the discontinuity in slope at the smectic A-nematic transition. (After...

Hyperfine transitions in the p He+ and p He+ atoms studied using combined laser and microwave spectroscopy in order to measure the magnetic moment of the antiproton (Widmann et al. 2002) in the atomic bound state (a) level splitting (b) the measured spectrum number of forced antiproton annihilations against the microwave frequency... 

Vanin et al. studied order proflles of the perdeuterated laurate chain in chiral and achiral phases by means of deuterium NMR. The quadrupole splittings measured for the sequence of CD2 moieties are all quite similar for the nematic and chiral nematic phase the conclusion was that chiral distortions of the micellar shape must be very small. Their proposal for the mechanism behind the phase chirality is analogous to the one for polypeptides an asymmetric point charge distribution which in this case was speculated to be created by the chiral dopant on the micellar surface [19]. Radley and Tracey prepared samples from a racemic detergent and observed high fluidity, whereas those consisting of some enantiomeric excess showed a significantly increased viscosity [30]. But this is no proof for the association of micelles to necklaces. 

Of spectroscopic teclmiques, nuclear magnetic resonance (NMR) has been most widely used to measure orientational ordering in liquid crystals [M, 57 and ]. Most commonly, changes of line splittings in the spectra of... 

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