Solid State Phenomena Vol. 208

Abstract: The aim of the experiment was to study the brain's response to the sound stimuli at a specific frequency. The relation between the specific sounds and the changes in the electrical activity of the brain, caused by it, may be helpful to develop the treatment methods of the various disorders of the brain, using the sounds. The aim of the experiment described in the article is to determine the changes in the signal spectrum during the sounds performance with different parameters and to relate it to the basic rhythms, occurring in the EEG signal.

Abstract: Ropes, including steel wire ropes, are the essential component of the kinematic chains in many passenger and cargo transport systems. Their condition also determines the level of operational safety of those devices. The article is devoted to discussion of methods of assessing the condition of steel wire ropes. The paper discusses magnetic and visual methods. Both methods are used obligatorily to assess ropes employed in rope transport systems. The most significant advantages of the magnetic method and the capabilities of modern methods of analysis of signals obtained from such studies are described. An important part of this article is showing how to determine the geometrical parameters of ropes during a routine evaluation of the degree of wear. The second part of the article presents new methods of determining and recording the geometrical parameters of ropes based on vision systems. The original method of determination of those parameters described herein is complementary to the currently used methods of assessment of the wear of both steel wire ropes and the increasingly more common synthetic fibre ropes. The method is based on the analysis of vision signals. Images of rope surface are created using 3D technology. The article presents some results of research based on which it is possible to identify the geometric dimensions of ropes as well as defects on the surface of those ropes. Such identification is possible on a digital image of a projection of rope surface.

Abstract: Continuous supervision of mechanical endurance is very important in the time of the advance constructions. The Self-excited Acoustical System (SAS) is a kind of a self-oscillating system, which uses the auto-resonance phenomena for measurement of construction stress changes. The advantage of this solution is the ability to apply it to a wide spectrum of materials from elastoplasts to brittle ones where the conventional techniques cannot be used. The Self-excited Acoustical System is characterized by its great sensitivity in comparison with the traditional techniques. This paper presents the results of the research carried out on a metal bar expanded by variable force. The dependence between the relative elongation of the sample and the transition time of the wave was elaborated. The delay occurring during a wave transition has a direct impact on the value of self-oscillation frequency. The influence of the coupling force between a metal sample and the wave receiver was also analysed.