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The paper formulates a method of active reduction of structure vibrations in the selected resonance zones of the tested object. The method ensures reduction of vibrations of the selected resonance zones by determining the parameters of the active force that meets the desired dynamic properties. The paper presents a method for determining the parameters of the active force by reducing the vibrations of the structure in its resonance zones to a given vibration amplitude. For this purpose, an analytical form was formulated, which will clearly define the dynamic properties of the tested object and the force reducing the vibrations in the form of a mathematical model. The formulated mathematical model is a modified object input function, which in its form takes into account the properties of the active force reducing the vibrations. In such a case, it is possible to use the methods of mechanical synthesis to decompose the modified characteristic function into the parameters of the system and the parameters of the force being sought. In the formulated method, the desired dynamic properties of the system and the vibration reducing force were defined in such a way that the determined parameters of the active force (velocity-dependent function) had an impact on all forms of natural vibrations of the tested system. Based on the formalized method, the force reducing the vibrations of the four-story frame to the desired displacement amplitude was determined. Two cases of determining the active force reducing the vibrations to the desired vibration amplitude of the system by modifying the dynamic characteristics describing the object together with the active force were considered. For both cases, the system's responses to the oscillation generated by harmonic force of frequencies equal to the first two forms of natural vibrations of the tested system were determined. In order to verify the determined force reducing the vibrations of the object and to create a visualization of the analyzed phenomenon, the building structure dynamics were analyzed with the use of PLM Siemens NX 12 software. The determined force parameters were implemented into the numerical model, in which the tested system was modelled, and the response time waveforms were generated with regard to the considered story. The generated waveforms were compared with the waveforms obtained in the formalized mathematical model for determining the active force reducing the vibrations. The vibrations of the tested numerical model were induced by the kinematic excitation with the maximum amplitude equal to 100 mm, which corresponds to the vibration amplitude during the earthquake with a force equal to level 5 on the Richter scale. [ABSTRACT FROM AUTHOR]

The article presents and discusses the results of research on hazard, especially temperature, for selected lithium-ion-phosphate cells operated in accordance with the manufacturer's recommendations but used under onerous mining conditions. This applies to the performance of cells in battery sets without the application of any management system (BMS). On the basis of the obtained test results, first of all, the influence of the value of the charging current of cells and the ambient temperature for both free and deteriorated heat exchange, appropriate conclusions and practical recommendations were formulated. This applies especially to threats in the case of random, cyclic, minor overloading, and discharging of the cells. [ABSTRACT FROM AUTHOR]

Description of design and rules of operation of transducer for detection of trackway surface condition in mine underground workings is the project objective. Information about the surface condition collected with use of the transducer will enable adaptive (depending on track surface conditions) control of breaking torque of wheels of rail locomotives and, in a result, shortening of braking distance by minimization of slippage. At first the requirements for braking systems of mining locomotives, with reference to real conditions of their operation, will be presented. Then selected braking systems, which are applied in the locomotives used in the coal mine industry, will be described with a special attention paid to the solutions, which potentially shorten the braking distance, including also the solutions based on ABS system used in the automotive industry. A concept of dedicated transducer, task of which is a continuous detection of surface condition of trackway, on which the locomotive moves, will be described with reference to the presented solutions. Transducer for detection is based on frictional coupling between its active component (so-called "tracking wheel") and a rail. Presented concept will be proved by a series of verification experimental tests. Presentation of tests results and determination of further directions of R&D work as regards discussed problems will be the summary of the project. [ABSTRACT FROM AUTHOR]