Impurity effects in carbon fibres

Outgassing experiments have been performed on a variety of polyacrylonitrile- and rayon-based carbon yarns. Major residual impurities, as well as those introduced from surface treatments, have been identified. Sulphur has been shown to be a major impurity of rayon-based carbon fibres, with concentrations up to 3110 ppm by weight having been determined by neutron-activation analyses. Removal of this contaminant as a volatile material commences at approximately 1300° C. Interrelationships between sulphur removal and mechanical and crystallographic properties have been considered for one rayon-based carbon yarn. Decreases in both interlayer spacing and tensile strength are associated with sulphur evolution, whereas apparent crystallite size and Young's modulus are unaffected by the outgassing.     

Body image, physical attractiveness, and depression.

224 17–63 yr olds completed measures of self-perceived physical attractiveness and depression, and static full-body videotapes of Ss were assessed by objective raters, to investigate the relationship between Ss' body image, rated physical attractiveness, and depression. Measures included the Body-Self Relations Questionnaire, Center for Epidemiologic Studies Depression Scale (CES-D), a body parts satisfaction scale, and a self-labeling depression scale. Ss were classified as depressed (n?=?35) or nondepressed (n?=?42) on the basis of conjunctive criteria of self-labeling and extreme groups on the CES-D. It was hypothesized that (1) depressed Ss would report being less satisfied with their body parts and physical appearance and would regard themselves as less physically attractive than would nondepressed Ss, (2) objective raters would perceive depressed Ss as less physically attractive than nondepressed Ss, and (3) depressed Ss would distort their degree of physical attractiveness and perceive themselves to be less attractive than objective raters regarded them. Results indicate that, as hypothesized, depressed Ss were less satisfied with their bodies and saw themselves as less physically attractive than nondepressed Ss. These groups did not differ with respect to observer-rated physical attractiveness. Support was obtained for A. T. Beck's (1973, 1976) cognitive hypothesis that depressed persons negatively distort their body images; however, results also indicate substantial positive distortion among nondepressed Ss. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)