Studies of systems with energy regeneration have been carried out for years, because they primarily cover the assemblies with electrodynamic actuators. This paper addresses the issue of active reduction of mechanical vibration using an electrohydraulic actuator. The testing procedure aims to assess the potential use of those assemblies in a different frequency band and force range than in electrodynamic actuators. The paper explains the operating principle of the system, and the findings of laboratory tests are presented. The tested vibration reducing system is the physical model of a 2 degree-of-freedom (DOF) suspension. An initial analysis has been conducted to explore the potential use of the energy produced by the vibration of unsprung mass in the first degree of the suspension system, for power supply to the active component incorporated in the second suspension degree. The energy recuperated from the first suspension DOF is transferred by a dedicated hydraulic system and stored in an accumulator. Results of the experiments revealed that the mechanical parameters of the system can be selected in such a way that for specific interfering signals the accumulated energy should be at least equal to the energy used up by the system.

No abstract

No abstract

Considering the nutritional values, breadstuff plays a big part in covering human nourishment needs and constitutes a base of all day diet. Moreover, bread is an excellent source of numerous vitamins and minerals the abundance of which depends on the degree of grinding. Thus, it seems to be very important to know the composition and level of bio-elements. That is why the main target of this study was to evaluate the concentration of selected trace elements: chromium (Cr), nickel (Ni), iron (Fe) and manganese (Mn) in wheat grain, wheat bran, different wheat and rye flour types and variety of breadstuff also with addition of grains and seeds from different bakeries and mills. Another task was to analyze if the technological process has an influence on secondary despoil of bread goods with heavy metal elements. The analyzed trace elements were measured with a precise and accurate atomic absorption spectrophotometric method (AAS) and the results were expressed in mg/kg of selected sample. Obtained results show that bread and grain products are a good source of trace elements like chromium, nickel, iron and manganese. However, the higher levels of chromium and nickel in bread goods could rather be an effect of impurity caused by a technological process in mill and bakeries.

In the presented paper the problem of balance platform control was considered. The object used during research is the original structure, designed by article authors. The work was divided into three parts: the identification process, control system design and laboratory tests. In the first stage of the identification process a model describing the system was build, using the measurement data recorded on input and output system. The model was built without the knowledge of the mechanisms that occur in the process; only based on the relationship between the measured data. Next the estimation was performed for selection of suitable algorithm, and determination of the parameters of model selected in the previous step. The last step was to verify and to check the results of identification process. By comparing the signals obtained in response to a signal given from the model of a registered object actual output signal, it is possible to visually estimate the accuracy of the identification and designation of the error. After identification process the control system was designed. In this application the PID controller was chosen. It was used to balance platform position and velocity control. The last part of the article shows the results of various laboratory tests and comparison of quality control.