The article presents an experimental study of a system consisting of a piezoelectric energy harvesting device, Graetz bridge rectifier, capacitor, voltage comparator and radio transmitter. In the presented experimental study, the recovered electrical energy is accumulated in the capacitor and is used to send signals by a radio transmitter. In the first part, the application of piezoelectric energy harvesting devices based on the cantilever beam in wireless monitoring systems is discussed. In the second part, the mathematical model of energy conversion in the piezoelectric energy harvesting devices is presented. In the third part, the characteristics obtained during laboratory research are presented.

Energy harvesting from mechanical vibration of buildings is usually realized by the use of devices, in which the main element is a prismatic beam with a rectangular cross-section. The beam has been the subject of scientific research; it is usually constructed with a carrying substrate that does not have piezoelectric characteristics and from piezoelectric material. In contrast, this investigation sought to create a beam structure with a piezoelectric composite only. The entire beam structure was made of a prototype piezoelectric particulate composite. Based on courses of voltage obtained in laboratory experiments and known geometry of the specimens, a series of finite element method (FEM) simulations was performed, aiming to estimate the piezoelectric coefficient d₃₁ value at which the mentioned voltage could be achieved. In each specimen, sedimentation caused the formation of two distinct layers: top and bottom. The experiments revealed that the presented prototype piezoelectric particulate composite converts mechanical stress to electric energy in bending mode, which is used in energy harvesting from mechanical vibration. It is self-supporting and thus a carrying substrate is not required in the harvester structure.

We present information about construction tasks of tracked vehicle model in MSC.ADAMS computer program. Kinematic and dynamic relationships inside entire suspension system are described here. Elements of the vehicle are grouped in few subsystems, like suspension, wheels or tracks. The significant accent is put on the tracks with its force connections. Those connections are between all track links as also between wheels, links and ground surface. Also significant accent are put on damping value estimation. It is estimated based on tolerance area of characteristics of real damper element, which is applied in this type of vehicles. In next part of the article, process of appropriate damping characteristics selection is described. This process is applied for high fidelity model building.

The paper presents the methodology of determination of emissivity coefficient of steel in the direct cooling temperature range, which allow self-definition of this parameter in automated temperature control system used for direct cooling of drop-forged parts. Based on the actual temperature of the surface of the workpiece, the system automatically adjusts the velocity of fan-forced air to produce desired cooling rate and course of cooling curves. To enable automatic correction of cooling rate, the system must rely on exact remote temperature measurements. This is conditioned by correct definition of emissivity in pyrometer gauge system. Traditionally, pyrometers use presets of a constant value, selected as to get optimum consistency for the temperature range concerned. As the emissivity is time-dependent, the idea of the approach presented in the paper is to use time dependent characteristics, to attain the minimum discrepancy between actual and measured values during the whole cooling cycle.

A beam containing a piezoelectric layer or layers is used for piezoelectric harvesting from various processes. The structure of the beam is made by gluing the piezoelectric material on one side (unimorph) or both sides (bimorph) of a carrying substrate. Two piezoelectric layers, glued on both sides of the substrate, may be electrically parallel or series connected. This paper presents an experimental analysis of the impact of parallel and series connections of two Macro Fiber Composite (MFC) MFC patches in a bimorph on the charging of a capacitor. In experiments, the effective charging process of the capacitor was obtained both for parallel and series connection of two MFC patches. The bimorph with a parallel connection generated a larger capacitor charging power than the bimorph with a series connection in the range of voltage across the capacitor from 1 to 18 V. However, the bimorph with a series connection was more effective than a parallel connection for voltage across the charged capacitor from 18 to 20 V. The maximum capacitor charging power generated by the bimorph, in which two MFC patches were parallel connected, was 1.8 times larger than that generated by the bimorph with a series connection and was 3.3 times larger than that generated by a unimorph with one MFC patch. The impact of level of voltage across the capacitor on its discharging process has a significant meaning for the ratio of maximum power between bimorphs and between the bimorph and unimorph.