The hereby paper discusses the influence of cable length on the SHM systems with the use of vibrating wire dynamic measurements. Vibrating wire sensors are mainly used for measuring stable or slowly changing strains, e.g. system installed on Rędziński Bridge in Wroclaw. From some time applications of these sensors for measuring dynamic deformations are becoming popular. Such tests were conducted on STS Fryderyk Chopin. New solutions generate new problems. In this case: the operational stability of systems exciting wire vibrations. The structure of such sensors and the electric cables length has an essential influence on their operations, what is undertaken in the paper. The subject of investigations constitutes the measuring system based on self-exciting impulse exciter, for which impedance parameters of electric cables and of the vibrating wire sensor were the most essential. The mathematical model of the system, experimental verification of the model as well as the results of theoretical analyses at the application of electric cables of various lengths are presented in the paper.
The paper presents results of the laboratory tests made for the prototype resilient under sleeper pads in the Warsaw University of Technology laboratory unit. These pads are dedicated to reduce vibrations transmitted to the vicinity of the railroad and to improve the resistance of the railroad structure. The laboratory testing program was carried out for elastomeric materials (polyurethane and rubber based) due to the PN-EN 16730 standard. The obtained values of the key parameters were used in order to determine the insertion loss vibration level by applying analytical method. The paper presents the influence of selected parameters i.e. static and dynamic moduli on the reduction of vibration and structure-borne sound level.
P.F. Strawson and J.L. Austin approach the problem of other minds from different perspectives. Peter Strawson looks at this problem from the perspective of descriptive metaphysics, which largely disregards the concrete situations in which we use mental language. John Austin, on the other hand, believes that to understand what is happening in such situations holds the key to solving the former problem. However, as it turns out, the considerations of both authors in the key fragments rely on similar observations. In addition, Austin’s perspective, which looks at the language from the point of view of its usage, makes it possible to formulate an answer to the Strawson’s critics. This does not exclude the possibility of agreeing with Strawson on the primacy of the reference function of language, if we understand it properly. Ultimately, Strawson and Austin’s approaches do not compete, but complement each other.
Most philosophers believe that a unified philosophical account of mental and non -mental actions is possible. This article presents two arguments indicating that in fact it is not possible. The first one says that thinking is not an activity. Its formulation, however, is exposed to significant difficulties. The second argument avoids these difficulties and puts forward a different, though sometimes erroneously identified, thesis that mental and non-mental actions differ significantly, and therefore one theory should not be expected to include both phenomena. Acceptance of this result sheds new light on the problems associated with the language of thought and gives promise to a new answer to the question “What is Le Penseur doing?”
On the 14th of February, 2015, a huge fire broke out on Łazienkowski Bridge; a five span bridge, 423 m long and 28 m wide, built in the years 1972-74. It was a fully steel structure with four plate girders and orthotropic deck. The fire started under the first span during the replacement of wooden service decks. The next day, the Department of Bridges of the Warsaw University of Technology was designated to conduct an expertise material investigation, geometrical verification, and FEM model analysis. The subject of this paper concentrates on geometrical issues. The main difficulty of this task was the lack of full reference data regarding the bridge's original structure. The old design was incomplete and there was no actual surveying results for the undamaged structure. As a conclusion, some remarks focused on surveying measurements and on the final decision regarding this bridge are given. It was eventually exchanged into a brand new one and put into public use on the 28th of October, 2015.