The vibrodiagnostic system VDS-UT2 was developed for the investigation of a tram wheel operational vibration and deformation. The system consists of measuring, acquisition and processing tools for monitoring of tram wheels and their operational parameters, e.g. static and dynamic deformation, displacement, velocity, acceleration and temperature. The measuring on a rotating wheel is realized both by telemetric and by top-timing system. Measured data can be remote-observed via Internet connection with the control PC. The acquisition system by Starmans Electronics s.r.o. provides continuous analog and digital data logging. The control PC processes digital logical signals and evaluates time intervals representing circumferential turning angles between disk and rim.. In the contribution, the diagnostic system is described and the measured data including damage analysis are presented. and Obsahuje seznam literatury
The most frequently applied criteria of the quality of optical surfaces and elements are analysed in detail in this article. There are described both geometrical-optics criteria and criteria based on diffraction theory of imaging. Relationships between different image quality criteria and geometrical aberrations are presented as well. Some terms lacking classical analogy in optics are also mentioned, such as the focal length of a plane parallel plate, prism etc. and V článku je uvedena podrobná analýza kritérií kvality optických ploch a prvků, které se v praxi nejčastěji vyskytují. Jedná se jak o kritéria geometricko-optická, tak i o kritéria založená na difrakční teorii zobrazení. Je ukázána souvislost jednotlivých kritérií s geometrickými aberacemi a jsou vysvětleny některé pojmy, které se v klasické optice nevyskytují - např. ohnisková vzdálenost planparalelní desky, hranolu apod.
Differences in soil stability, especially in visually comparable soils can occur due to microstructural processes and interactions. By investigating these microstructural processes with rheological investigations, it is possible to achieve a better understanding of soil behaviour from the mesoscale (soil aggregates) to macroscale (bulk soil). In this paper, a rheological investigation of the factors influencing microstructural stability of riparian soils was conducted. Homogenized samples of Marshland soils from the riparian zone of the Elbe River (North Germany) were analyzed with amplitude sweeps (AS) under controlled shear deformation in a modular compact rheometer MCR 300 (Anton Paar, Germany) at different matric potentials. A range physicochemical parameters were determined (texture, pH, organic matter, CaCO3 etc.) and these factors were used to parameterize pedotransfer functions.
The results indicate a clear dependence of microstructural elasticity on texture and water content. Although the influence of individual physicochemical factors varies depending on texture, the relevant features were identified taking combined effects into account. Thus, stabilizing factors are: organic matter, calcium ions, CaCO3 and pedogenic iron oxides; whereas sodium ions and water content represent structurally unfavorable factors. Based on the determined statistical relationships between rheological and physicochemical parameters, pedotransfer functions (PTF) have been developed.
The paper derives fundamental formulae for calculation of large deformations of circular axisymmetric elastic membranes under uniform pressure and then presents and compares several possible solutions. The thorough study gives reader an opportunity to query the matter in detail and therefore to understand the limitations which can occur during calculations of large deformations of membranes. and Práce detailně odvozuje základní vztahy pro výpočet velkých deformací kruhových axisymetrických elastických membrán zatížených rovnoměrným tlakem a následně představuje a srovnává několik možných řešení. Hloubka studie nabízí čtenáři možnost podrobně nahlédnout do problematiky, a tedy dostatečně porozumět úskalím, která při výpočtech velkých deformací membrán mohou nastat a nastávají.