On the Vibration-Damping Properties of the Prestressed Polyurethane Granular Material.

Granular materials promise opportunities for the development of high-performance, lightweight vibration-damping elements that provide a high level of safety and comfort. Presented here is an investigation of the vibration-damping properties of prestressed granular material. The material studied is thermoplastic polyurethane (TPU) in Shore 90A and 75A hardness grades.

Computer simulation of anisotropic polymer brushes.

A polymer brush with chains consisting of anisotropic monomers, in a liquid consisting of free spherical particles, is studied by the molecular dynamics method. It is shown that, at some value of the concentration of spheres, a liquid-crystal or oriented-domain transition occurs in the brush. A densely-grafted brush and a sparsely-grafted brush are studied; for this system, the transition point seems not to depend strongly upon the grafting density.

Dynamic characteristics of the thorax connected with the heart action.

We determined the indices of local vibrations (resonance frequency, damping coefficient, stiffness constant, extinction time) and transfer function H(s) . 10(-6) for three somatotypes and three respiratory positions on 88 points of the thorax. The examinees were males (age 21 years).