In this study, ceramic plate behaviour was elaborated on the basis at sound signal variations caused by the impact. All tests were performed using plate specimens and pendulum testing station; with date acquisition and analysis systems. Two various methodologies such as; spectral and statistical were used. In the spectral analysis, power spectral densities were calculated for both virgin and cracked specimens with rage of frequency 0-33kHz. In the case of this frequency range was separated in to two repairs i.e. 0-28 kHz and 28-33 kHz. Differences in sound signals of virgin and cracked plate specimens were significant. The effect none related with cracked specimen spectral behaviour and it property can be interpreted as absorption of the vibrational effects in the cracked regions. An analysis of statistical results has shown a smaller value of skewness for virgin specimen than cracked one, case show smallest skewness value than the healthy cases skewness value.

In this paper, wind speed measurements are considered for Mardin region in Turkey. Mardin city is situated in East part of Turkey. Mardin is a mountainous area suitable for wind. And also, its wind energy potential is at an acceptable level. Wind speed data in this study, is obtained from the national meteorology station. This realtime measured data is suitable to international criteria. This annual data is related to the measurements of 2011, from January 1, 2011 to December 31, 2011. There are two important aspects of the study. First one is related to calculation of the statistical parameters for wind speed data. Here four parameters of a statistical distribution are calculated. These are mean value, standard deviation, skewness and kurtosis. Last two parameters are used to determine the non-Gaussian (or Gaussian) characteristics. In this study, the skewness and kurtosis parameters are are calculated and compared. Parameters indicate asymmetrical and non-Gaussian characteristics. Hence the wind speed distribution is defined by Weibull distribution and its probability density function is shown for shape parameter and average speed of the wind. Thus the histogram and Weibull probability density function are calculated as well as the statistical findings. As a second aspect of the study, data is accepted as non-stationary. So its Continuous Wavelet Transform is used for the determination of the seasonal transitions and determined the time-frequency content. Thanks to the continuous wavelet transform, low and high frequency regions of wind speed data are distinguished. Continuous wavelet transform findings are quite satisfactory.

This study presents the results of electromagnetic field parameters measurements in an open area under different air temperature and humidity conditions. An attempt to consider the electromagnetic wave as a holistic harmonic oscillation, which takes into account all frequency components of the field at the measurement point, was also presented in this study. During the measurements, the closest electromagnetic radiation sources were taken into account. Therefore, measurements of field parameters were produced in specific frequency bands. For the simplification of large data, the spectrum decimation technique was applied. As a result, measurements and data processing were revealed to characterize the electric field strength and the magnetic flux density when air temperature increases. The field parameters dependences on air relative humidity have a decreasing tender.

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This paper deals with oscillating linear synchronous pulsating current motor compressor drive supplied by sinusoidal and rectangular voltage. While creating mathematical model of the motor for investigation, Matlab software was used for solving of differential equations. Modeling results while supplying motor by sinusoidal and rectangular voltage and changing firing angle a of thyristor, frequency of voltage f and a load R. Characteristics and energetic parameters of oscillating linear pulsating current motor were obtained and analyzed. Ill. 10, bibl. 6, tabl. 2 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.278