This review discusses the mechanisms of generation and potential impacts of microplastics in the ocean environment. Weathering degradation of plastics on the beaches results in their surface embrittlement and microcracking, yielding microparticles that are carried into water by wind or wave action. Unlike inorganic fines present in sea water, microplastics concentrate persistent organic polluta...

The wave-like damage structures on the entrance surface of optical media, which observed in various experimental studies with nanosecond laser pulses, are analysed. Sometimes such appear as a system straight lines intersecting at an-gles defined by crystallography sample. It is proposed that stimulated radial scattering layer sample responsible for their formation. Keywords: radical scattering,...

An acoustic method is proposed for measuring the flow resistivity and the thickness of air-saturated porous materials. The conventional methods [14, 16, 17] for the measurement of the flow resistivity (or the viscous permeability) require the prior knowledge of the porosity. The method presented in this work is based on a temporal model of the direct problem in which a simplified expression (in...

In this article, we compare direct image transmissions through various multimode optical fibers, namely, step-index silica, graded-index silica, and step-index plastic fibers. We make use of a round-trip transmission in the optical fiber as well as a phase-conjugate wave generated by a self-pumped BaTiO3 crystal to recover a distorted image. The image was best recovered for a step-index silica ...

The purpose of this note is to propose an improvement to the widely-used Steinberg-Lund model for rate-dependent plasticity. The improved model is rate-dependent above, as well as below, the Peierls stress. As a result of this change, one material constant in the Steinberg-Lund model acquires a new value, and we thereby obtain a revised estimate for the dislocation density in tantalum. 1. Intro...