Some extensions of elementary plasticity theory

A detailed investigation is presented of yield or loading criteria, for work hardening materials, which lead to constant strain ratios under increasing stress when stress ratios are maintained constant. The experimenter is given a choice of incremental stress-strain theories with which results of simple or complicated combined loading tests may be correlated. These theories are dealt with in order of increasing complexity and, at the same time, increasing capacity to represent experimentally established phenomena.The objective is the use of the mathematically simplest theory which will provide the desired flexibility in the analysis of experimental data.Loading functions of isotropic as well as anisotropic types are examined, among them those depending explicitly on stress alone and those depending on both stress and plastic strain. In the latter cases only those functions are investigated in which plastic strain appears to the first order. The predicted results of some basic tests are examined for several loading criteria.     

Training boys with ADHD to work collaboratively: Social and learning outcomes

This study examined social participation and strategic problem solving behavior of boys diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) when collaborating on a planning task with a trained peer partner. Twenty-four 9- to 13-year-old boys with ADHD who were receiving a medication intervention, were individually pre-tested to assess their initial ability to plan an errand route task. They were then observed doing an alternate planning task during collaborative sessions with a female peer partner who had received prior training in the task and in facilitating social interaction. Boys with ADHD were then individually post-tested on the original planning task. Observations of the collaborative sessions revealed significant, positive changes across three phases in the quality of social interactions by boys with ADHD, in their planning strategies, and planning efficiency. Findings suggest positive benefits of collaborative learning structures for boys with ADHD when they are placed in a collaborative learning setting with a partner who has received a prior training intervention.