Group SH Research Articles

Control of Communication in Dyads by Reinforcement

This study examined effects of reinforcement on speaker vs listener role-taking in a dyad. Given the task of describing TAT cards, Ss obtained points, exchangeable for money, for talking or listening in a dyad. One S had control over the distribution of talk time, with the partner talking only upon request. The partner, E's confederate, was reinforced at a higher rate than S for talking (Group CH), an equal rate (Group HH), or a lower rate (Group SH). In all groups Ss increased talking over trials. This increase was greater in Group SH, next in HH, lowest in CH. Interactional pattern changes were due mainly to duration of utterances rather than the tempo in the verbal interchange.

Vulcanization of crepe rubber by sulfur monochloride. Part I. The gelation method

AbstractWhen a solution of natural rubber hydrocarbon is cold vulcanized with sulfur monochloride, a gel is formed. The rate of gel formation is used to characterize the rate of reaction between rubber and sulfur monochloride and a preliminary kinetic investigation is described. It is shown that the reaction is accelerated by compounds normally used for speeding up sulfur (hot) vulcanization, and it is suggested that these function by virtue of their possessing an active hydrogen atom. Several series of simple compounds, containing the groups SH, OH, and NH2, are shown to function as effective accelerators and their activity is attributed to the presence of a labile hydrogen atom in the molecule RXH, where R = organic radical and X = S, O, or N. The absence of a direct relationship between accelerating power and basic or acidic strength suggests a free radical mechanism of accelerator action, based upon the process ${\rm R} - {\rm X} - {\rm H } \to {\rm R} - \mathop {{\rm X }}\limits^ * {\rm + }\mathop {{\rm H }}\limits^ * $.