Theory and research on media violence provides evidence that aggressive youth seek out media violence and that media violence prospectively predicts aggression in youth.The authors argue that both relationships,when modeled over time, should be mutually reinforcing, in what they call a downward spiral model. This study uses multilevel modeling to examine individual growth curves in aggressivene...

A review of modeling techniques for predicting the mechanical behavior of polymer nanocomposites is presented. A detailed discussion of Computational Chemistry and Computational Mechanics modeling techniques is given. The specific molecular-based and continuumbased modeling approaches are described in terms of assumptions and theory. The approaches discussed are Ab initio simulations, Molecular...

The Halpin-Tsai equations are based upon the “selfconsistent micromechanics method” developed by Hill. Hermans eniplovetf this model to obtain a solution in terms of Hill’s “reduced moduli”. Halpin and ’Tsai have reduced Hernians’ solution to a simpler analytical form arid extended its use for a variety of filament geometries. The development of these niicromechanics relationships, which form t...

This paper presents an experimental and numerical study of the folding behavior of thin composite materials consisting of carbon fibers embedded in a silicone matrix. The soft matrix allows the fibers to microbuckle without breaking and this acts as a stress relief mechanism during folding, which allows the material to reach very high curvatures. The experiments show a highly non-linear moment ...

A new model for damage evolution in polymer matrix composites is presented. The model is based on a combination of two constituent-level models an9 an interphase model. This approach reduces the number of empirical parameters ·since the two constituent level models are formulated for isotropic materials, namely fiber and matrix. Decomposition of the state variables down to the micro-scale is ac...

This paper presents a three-dimensional constitutive model for shape-memory alloys that generalizes the one-dimensional model presented earlier (Sadjadpour and Bhattacharya 2007 Smart Mater. Struct. 16 S51–62). These models build on recent micromechanical studies of the underlying microstructure of shape-memory alloys, and a key idea is that of an effective transformation strain of the martensi...

The problem of development microequipment is discussed. This paper contains description of the main problems connected with micro mechanical equipment developing, requirements to the micro machine tools properties, design and control systems of the prototypes of first generation machine tools, and applications of micro equipment. The mayor idea of this paper is to show the experience of the Lab...

Relations between fracture toughness and microstructural details have been calculated for ductile materials based on a dilatational plasticity constitutive model that has recently been proposed. The model generalizes the Gurson model to account for both void growth and coalescence with explicit dependence on void shape and distribution effects. Based on a small scale yielding formulation of cra...