Photoselective resonance Raman scattering from laser ablation grown single-wall carbon nanotubes is demonstrated to be consistent with a response from tubes with all geometrically allowed helicities. This information is drawn from an analysis of the resonance scattering by combining ab initio calculations for the mode frequencies with evaluations of the resonance cross sections for isolated tubes. The resonance excitation was found to exhibit an oscillatory behavior. To match the experiments and the calculations, the frequencies obtained from the latter must be up-shifted by 8.5% on the average. This stiffening is ascribed to the tube-tube interaction in the carbon nanotube bundles.

In early studies, research to control byssinosis focused on methods to reduce the trash in the textile mill environment. Dust control has been effective in reducing the prevalence of byssinosis, but simple reduction in dust levels does not always assure its prevention. Also, bacteria and fungi present in cotton do not in themselves cause byssinosis, but the endotoxins-heat-stable lipopolysaccharide-protein complexes contained in the cell wall of Gram-negative bacteria-are responsible for the development of this respiratory disease of workers on cotton, flax, and some other fibers. Experimental work was carried out in cotton fields in different cotton growing countries. Opened cotton capsules were treated by spraying them with bactericidal water solutions of benzododecinium bromide to avoid the growth of bacteria by bacteriostatic effect during transportation and storage and thus to prevent the formation of endotoxins. To simulate transport conditions, treated and nontreated cotton samples were incubated under high air humidity. The endotoxin contents were determined by Limulus amebocyte lysate assay depending on the duration of incubation. In nontreated samples the endotoxin content grew to over 5,000 ng/mg. In comparison, in treated samples the endotoxin content grew extremely slowly. Thus, the bactericidal treating of raw cotton showed high efficiency as a potential method of byssinosis prevention. The irradiation by gamma-rays is also efficient, but it is not realistic in cotton growing areas of developing countries at the present time.

The method of electrical dislocation density measurement, which was successful in plastically deformed pure noble metals, is applied for the first time to dilute alloys, and the parameters for the electrical dislocation density measurement, i.e. the temperature dependence of the deviation from Matthiessen's rule and of the low-field Hall coefficient were investigated in Cu±Au alloys with 0.075 and 0.3 at% gold. The results for the dislocation density, which rely on the modelling of the true dislocation resistivity by means of the two-group model are especially satisfactory for the 0.075 at% alloy. Additionally the dislocation density was checked by X-ray Bragg profile analysis. The comparison of the latter method with the electrical method shows that small dislocation loops originating from the agglomeration of deformation induced vacancies are part of the total dislocation density.

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