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Historic harbour brick objects are subject to large dynamic loads clearly reflected by generated vibration processes. The vibrations may affect state of serviceability of structures by lowering comfort of persons working there as well as possible reaching the level hazardous to safety of the structures. The effect of vibrations to structure is mainly manifested by additional stresses in a given cross-section, which are summed up with those resulting from static loads. Moreover often occur consequences associated with environmental conditions and fatigue of materials which accelerate destruction of the objects. Therefore the dynamic loads may cause damaging effects in buildings of various structural types or even lead to their catastrofic destruction. Judging the necessity of improving the quality assessment methods of building structures for purposes of estimation of their state as well as safety factors for brick structures (see PN-B03002 standard, p.3.1.3 and 4.6), the author of this work undertook an attempt to investigate destruction process of selected building structures by using the method of operational modal analysis
In this work - in view of still decreasing crude oil resources and increasing fuel prices - are presented issues concerning research on development of other, alternative fuel sources including those used in water, land and air transport means. One of them is hydrogen which,while burning, does not produce noxious carbon dioxide but only side effects such as heat and clean water. It is almost true that along with sudden drop of availability and rising price of crude oil many countries face economical paralysis. Any of alternative sources is not capable of supplying even only a basic amount of such energy, not mentioning the whole amount of energy demanded by our civilization. Hydrogen as an independent fuel for internal combustion engines has yet to go a long way to commercialization. to be Co-burning systems (combustion of mixtures )of today used hydrocarbon fuels combined with hydrogen seem closer to this aim. As proved in many investigations the substitution of a part of hydrocarbon fuel by hydrogen enables to make use of beneficial features of both the fuels. One of possible solutions of the problem may be application of an innovative hydrogenic fuel electrolyzer which is presented and evaluated in this paper
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Badania modalne pęknięć bloczków betonowych

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W przedstawionym opracowaniu wskazano na możliwość wykorzystania złożonych estymatorów rozpływu energii drganiowej wykorzystywanych w badaniu jakości bloczków betonowych w ramach opracowanej do tego celu metodologii badań drganiowych. Analizy teoretyczne i weryfikacja praktyczna badania wrażliwości informacyjnej miar złożonych procesów drganiowych wskazują na szerokie możliwości ich zastosowania. W celu doskonalenia metod badań uszkodzeń materiałów betonowych dla potrzeb oceny ich stanu degradacji, w tej pracy przedstawiono istotne wyniki postępowania badawczego w zakresie weryfikacji skuteczności proponowanych miar wzajemnych w badaniach stanowiskowych bloczków betonowych.
Dockside cranes must meet the relevant strength requirements that provide usefulness and not endanger the safety of their use. The vibration effect on structural safety hazard results from the impact of horizontal forces caused by the transport of goods for loading and transverse forces caused by wind, which can be dangerous for correct functioning. In addition, there are often serious effects of climate-related impacts of the environment, material fatigue, which actuates the degradation state of the object. Dynamic loads may therefor cause random effects that devastate the structures or lead to their catastrophic destruction. Recognizing the need to improve the testing methods of crane structures in order to assess their condition and assess their safety factors - this paper attempts to develop a methodology for testing the degradation of the selected portion of a construction crane - using experimental modal analysis, realized in simulation tests in the Inventor environment as well as at test stand research
This paper presents a methodology to evaluate the technical state of a Francis turbine by shaft rotor dynamic simulation. There are several rotor dynamic criteria that define the technical state of a turbo-machine. To feed the shaft rotor dynamic model this delivers the required information to accomplish the technical assessment. The numerical rotor dynamic model uses as input, the field forces obtained by the fluid-solid interaction analysis undertaken over the blades of the runner. The rotor dynamic numerical simulations allow to determinate the record-in-time of the displacements of any point along the shaft. This information is relevant for diagnosis tasks, because it is possible to decompose it spectrally and to estimate the severity of the vibrations. Comparing the results of the numerical model against those obtained from machines that operates under normal conditions, it is possible to determinate the technical state of the turbo-machine. This allows studying the stability of the turbine working on several operation ranges. A Francis turbine is a very complex machine that involves many physical phenomena of different nature. In this way, the hydraulic input forces needed by the rotor dynamic model should not be assumed but calculated directly from the fluid interaction over the turbine structure
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