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Recently, there have been experiments where the acoustic emission sensors have been used in the investigation of power semiconductor components. In this paper the authors present their observations of measurement related challenges they have encountered while doing such experiments. Special focus is on sensor related difficulties. The main result of this study is that while acoustic emission sensors...
Bacteriorhodopsin is considered an important biomolecule for biochemical and technology-oriented studies. The modeling and functionality of bacteriorhodopsin sensors have been extensively studied, but the studies lack the analysis of the errors present in the measurements. Further, the impacts of these errors on photoelectric measurements are mostly unknown. In this paper, we discuss the errors caused...
The photoelectric response of dry bacteriorhodopsin sensors varies depending on whether the incident light is on or off. To model this behavior, we have proposed an electrical equivalent circuit that has a capacitor that varies with the light intensity. In this paper, the proposed model is experimentally validated and found to be appropriate even when the light intensity is changed. The results also...
The authors show for the first time that acoustic events are related to the failure of transistors. An experimental setup is presented, that was used to make a sample of 26 insulated gate bipolar transistors (IGBT) to fail. The acoustic events in the transistors were monitored. It was discovered that two distinct types of acoustic events are related to the failure. This study complements recent work...
A recent paper showed that the switching operation of a power semiconductor module causes an acoustic emission to take place. In this study, that experiment is repeated using a different kind of acoustic emission sensor. The same conclusion is reached in this stydy as in the previous paper: an acoustic emission takes place as a result of the switching of a power module.
Electric vehicle competitions have been organized in order to test the limits of technology. In this paper, we describe a competition for students and the public. The competition was held in Lappeenranta in 2013. We also analyze what kinds of vehicles were used and what the winning strategy was.
Traditionally, condition monitoring of power semiconductor modules has been based on electrical measurements. Acoustic emission has been utilized for condition monitoring in many other applications, but is an unknown phenomenon in power semiconductor modules. In this paper, the authors present an experimental setup used to show that acoustic emission does occur because of the switching of power semiconductor...
Modeling the photoelectric response of dry bacteriorhodopsin (bR) sensors has commonly been carried out by following the theory of linear time-invariant systems. However, it has been reported that the time constants of the photovoltage responses of such sensors vary depending on whether the sensor is measured when the incident light is switched on or off. In this paper, we propose an electrical equivalent...
In this paper, the design and implementation of an energy measurement system for an electric vehicle competition is described. The system consists of PC-based software and a processor-controlled stand-alone measuring unit with an analog front-end, an SD memory card, a radio link, and a USB interface. The work was carried out as a part of a university project course. The designed system was experimentally...
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