The main object of this work is noise spectroscopy of CdTe radiation detectors (-rays and X–rays) and CdTe samples. The study of stochastic phenomenon and tracing redundant low-frequency noise in semiconductor materials require long-term measurements in time domain and evaluate suitable power spectral densities (PSD) with logarithmic divided frequency axes. We have used the means of time-frequency analysis derived from the discrete wavelet transform (DWT) and we have designed the effective algorithm for PSD estimation, which is comparable with an original analog method. CdTe single crystal with Au contacts we can imagine as a series connection of two Schottky diodes with a resistor between them. The bulk resistance at constant temperature and other constant parameters changes due to the carrier concentration changing only. The p-type CdTe sample shows metal behavior with every temperature changes. Semiconductor properties of the sample begin to dominate just after some period of time. This behavior is caused by the hole mobility changing. The voltage noise spectral density of 1/f noise depends on the quantity of free carriers in the sample. All the studied samples have very high value of low frequency noise, much higher than it should have been according to Hooge’s formula. The excess value of low frequency noise is caused by the low carrier concentration within the depleted region.

This diploma thesis deals with construction and technological solution of hotel Nábřeží near Kunovská dam. The aim of this work is to choose the appropriate construction process of rough construction. Thesis contains technical report of main object, technological prescription and test plan for reinforced concrete ceiling, work plan and schedule of work also project of site equipment, main construction machinery and noise measurement survey. Further there is financial and time demand comparison of existing and alternative design of vertical load-bearing system in the connection with thermal insulation.

Indiana University-Purdue University Indianapolis (IUPUI) / Non-invasive surface recording of bioelectric potentials continues to be an essential tool in a variety of research and medical diagnostic procedures. However, the integrity of these recordings, and hence the reliability of subsequent analysis, diagnosis, or recommendations based on the recordings, can be significantly compromised when various types of noise are allowed to penetrate the recording circuit and contaminate the signals. In particular, for bioelectric phenomena in which the amplitude of the biosignal is relatively low, such as muscle activity (typically on the order of millivolts) or neural traffic (microvolts), external noise may substantially contaminate or even completely overwhelm the signal. In such circumstances, the tissue-electrode interface is typically the primary point of signal contamination since its impedance is relatively high compared to the rest of the recording circuit. Therefore, in the recording of low-amplitude biological signals, it is of paramount importance to minimize the impedance of the tissue-electrode interface in order to consistently obtain low-noise recordings. The aims of the current work were (1) to complete the development of a set of tools for rapid, simple, and reliable full-spectrum characterization and analytical modeling of the complex impedance of the tissue-electrode interface, and (2) to characterize the interfacial impedance and signal-to-noise ratio (SNR) at the surface of the skin across a variety of preparation methods and determine a factor or set of factors that contribute most effectively to the reduction of tissue-electrode impedance and noise contamination during recording. Specifically, we desired to test an initial hypothesis that surface abrasion is the principal determining factor in skin preparation to achieve consistently low-impedance, low-noise recordings. During the course of this master’s study, (1) a system with portable, battery-powered hardware and robust acquisition/analysis software for broadband impedance characterization has been achieved, and (2) the effects of skin preparation methods on the impedance of the tissue-electrode interface and the SNR of surface electromyographic recordings have been systematically quantified and compared in human subjects. We found our hypothesis to be strongly supported by the results: the degree of surface abrasion was the only factor that could be correlated to significant differences in either the interfacial impedance or the SNR. Given these findings, we believe that abrasion holds the key to consistently obtaining a low-impedance contact interface and high-quality recordings and should thus be considered an essential component of proper skin preparation prior to attachment of electrodes for recording of small bioelectric surface potentials.