Using the Correlation Function in Ultrasonic Non-destructive Testing

This paper deals with ultrasonic signal de-noising by means of correlation. It is commonly known that the cross-correlation function shows the statistical dependence between two signals. In ultrasonic inspection, the measured signal is taken as the first signal. The most important aspect of this method is the choice of the second signal. Various types of the second signals can be tried

Reducing Ultrasonic Signal Noise by Algorithms based on Wavelet Thresholding

Traditional techniques for reducing ultrasonic signal noise are based on the optimum frequency of an acoustic wave, ultrasonic probe construction and low-noise electronic circuits. This paper describes signal processing methods for noise suppression using a wavelet transform. Computer simulations of the proposed testing algorithms are presented

Condition Indicators for Gearbox Condition Monitoring Systems

Condition monitoring systems for manual transmissions based on vibration diagnostics are widely applied in industry. The systems deal with various condition indicators, most of which are focused on a specific type of gearbox fault. Frequently used condition indicators (CIs) are described in this paper. The ability of a selected condition indicator to describe the degree of gearing wear was tested using vibration signals acquired during durability testing of manual transmission with helical gears.

Gearbox Condition Monitoring Using Advanced Classifiers

New efficient and reliable methods for gearbox diagnostics are needed in automotive industry because of growing demand for production quality. This paper presents the application of two different classifiers for gearbox diagnostics – Kohonen Neural Networks and the Adaptive-Network-based Fuzzy Interface System (ANFIS). Two different practical applications are presented. In the first application, the tested gearboxes are separated into two classes according to their condition indicators. In the second example, ANFIS is applied to label the tested gearboxes with a Quality Index according to the condition indicators. In both applications, the condition indicators were computed from the vibration of the gearbox housing.

Assessment of public health issues of migrants at the Greek-Turkish border, April 2011

A joint mission to assess the public health situation of migrants in Greek detention centres was undertaken in April 2011 by the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) Regional Office for Europe. The assessment visit follows the increased migration to the Evros prefecture, Eastern Macedonia and Thrace region, at the Greek-Turkish border where large numbers of migrants are entering Greece via the Evros River, a natural border. Migrants are housed in local detention centres. The main problem in detention centres are the substandard hygiene conditions, especially overcrowding and lack of personal hygiene facilities, lack of basic supplies and lack of access to fresh air and physical exercise. As the migration route via the Evros region is increasingly used since 2009, and due to the unstable political situation in North Africa and the Middle East, an increased influx of migrants was to be expected with the falling water levels of the Evros River in summer, resulting in further deterioration of the already critical situation in the Thrace region’s detention centres

Radial Velocity Variations in Pulsating Ap Stars III. The Discovery of 16.21 min Oscillations in Beta CrB

We present the analysis of 3 hrs of a rapid time series of precise stellar radial velocity (RV) measurements (sigma = 4.5 m/s) of the cool Ap star Beta CrB. The integrated RV measurements spanning the wavelength interval 5000-6000 Ang. show significant variations (false alarm probability = 10^-5) with a period of 16.21 min (nu = 1028.17 micro Hz) and an amplitude of 3.54 +/- 0.56 m/s. The RV measured over a much narrower wavelength interval reveals one spectral feature at 6272 Ang. pulsating with the same 16.21 min period and an amplitude of 138 +/- 23 m/s. These observations establish Beta CrB to be a low-amplitude rapidly oscillating Ap star.Comment: 5 Pages, 5 figure

Ethanol Vapours to Complement or Replace Sulfur Dioxide Fumigation of Table Grapes

Recent studies have shown that dipping table grapes in ethanol solutions at harvest improved storage of the fruit. We report here the first results obtained by treating "Chasselas" table grapes (Vitis vinifera) with ethanol vapours over the storage period. We tested the effect of ethanol at 0, 4 and 8 g/kg fruit during cold storage for 2, 4 and 6 weeks. We measured berry shatter, stem browning, Botrytis rot incidence and sensory appreciation by tasting panels. Ethanol vapours reduced Botrytis rot incidence and berry shatter, but hastened stem browning. Sensory analyses did not detect any differences between treatments

Diffraction in time of a confined particle and its Bohmian paths

Diffraction in time of a particle confined in a box which its walls are removed suddenly at $t=0$ is studied. The solution of the time-dependent Schr\"{o}dinger equation is discussed analytically and numerically for various initial wavefunctions. In each case Bohmian trajectories of the particles are computed and also the mean arrival time at a given location is studied as a function of the initial state.Comment: 8 pages, 6 figure

Melamine contamination of dairy products in China – public health impact on citizens of the European Union

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