Light scattering depolarization, 171 determination

Our experiments are typically carried out at DNA concentrations of 20-50 /ig/ml with 1 ethidium per 300 bp, so that depolarization by excitation transfer is negligible.(18) The sample is excited with 575-nm light, and the fluorescence is detected at 630, 640, or 645 nm. Less than one fluorescent photon is detected for every 100 laser shots. The instrument response function e(t) is determined using 575-nm incident light scattered from a suspension of polystyrene latex spheres. 

Cabannes factor analy chem An equational factor to correct for the depolarization effect of the horizontal components of scattered light during the determination of molecular weight by optical methods. ko banz. fak-tor cacodyl orgchem (CH3)2As A radical found in, for example, cacodylic acid, (CH3)2A-sOOH. kak-3 dil ... 

Single-bilayer DODAC (6) vesicles Magnetite particles prepared in situ in vesicles from Fe2+/Fe3+ and OH" Static and dynamic polarized and depolarized light scattering and static and time-resolved dichroic anisotropy, as well as conventional magnetization vs applied magnetic field determinations were used for characterization 794... 

The Brice-Phoenix light scattering photometer and the Absolute light scattering photometer were designed for the measurement of attenuation, dissymetry and depolarization. The former has also been used to determine the particle size distribution of an aerosol at various levels in a flowstream through a column [125]. 

Since, in HRS, there is no preferred orientation induced by an additional static field, there is the possibility of varying the experimental conditions in order to increase the number of independent observables. The number of theoretically possible independent observations, and hence the number of tensor components that can be obtained by HRS, is at most five. For parametric light scattering, this number is six, due to the possibility of distinguishing between the two optical fundamental fields [20]. The experimental difficulty has precluded the determination of this number of components. What is experimentally realistic in HRS is an additional depolarization measurement, apart from the classical measurement of the intensity of the second-order incoherent scattered light. The two measurements, the total intensity measurement and the depolarization ratio (or two intensity measurements, one with parallel and one with perpendicular polarization for fundamental and second harmonic), represent two independent observables and allow the experimental determination of two tensor components. For molecules of C2 symmetry, these are and P xxy resulting for the total intensity measurement in Eqn. (21),... 

N. Meinander, G. C. Tabisz, and M. Zoppi. Moment analysis in depolarized light scattering Determination of a single-parameter empirical pair polarizability anisotropy for Ne, Ar, Kr, Xe and CH. J. Chem. Phys., 54 3005-3013 (1986). 

The Gj parameter determines the magnitude of the Kerr constant as well as the depolarized light scattering intensities in fluids of linear nonpolar molecules. H0ye and StelP have developed general relations between G and the site-site correlation functions. Using these results, Sullivan and Gray showed that the Gj parameter for any symmetric linear molecule is identically... 

Badaire et al. reported the formation of liquid crystalline phase of CNTs by noncovalent functionalization with single strand DNA in water [74]. The nonco-valent functionalization in water is simpler and does not affect the intrinsic properties of the CNTs. They observed that a nematic-isotropic coexistence is observed for nanombes concentrations between 2 and 4 wt%. Above 4 wt%, the system forms a single nematic phase of unmodified and freely dispersed nanotubes. They investigated the boundaries of the phase diagram with respect to the aspect ratios of the nanombes determined by dynamic depolarized light scattering. Poulin et al. uniformly aligned the nematic aqueous suspensions of nanombes in... 

Tensor autocorrelation functions are measured in some experiments. A pertinent example is a coupled relaxation CNMR experiment [16, 33-38]. In this case, Cartesian tensors fixed in the molecular frame can be used to express the results of the relaxation experiments. In a depolarized light scattering experiment, reorientation the polarizability tensor determines the observed relaxation. 

The rod length and diameter can also be inferred from d5mamic depolarized Rayleigh scattering. The translahonal and rotational diffusion coefficients can be determined. The depolarized light-scattering correlation function can be expressed as ... 

---