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bands can be determined. The method used for this is the Fast Fourier Transform, or FFT, which is a faster version of the discrete Fourier transform. Butterworth filter Butterworth filters are of the type IIR, or Infinite Impulse Response filters

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The aim of the present paper is to show a simple, but well applicable solution to generate arbitrary waveform of magnetic flux density in scalar hysteresis measurements. The paper deals with a possible realization of eliminating the effect of measurement noise as well. First, the measured signals have been transformed into the frequency domain, and after applying digital filter, the spectrum of the filtered signals have been transformed back to the time domain. The proposed technique results in an accurate noise removal algorithm. The paper illustrates a fast controlling algorithm applying the inverse of the actually measured hysteresis loop, and another proportional one to measure any distorted flux pattern. Developing the mentioned algorithms aims the controlling of a more complicated phenomenon, i.e. measuring the vector hysteresis characteristics.

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Interventional Medicine and Applied Science
Authors:
Csaba Csobay-Novák
,
Zsuzsanna Járányi
,
Edit Dósa
, and
Kálmán Hüttl

Abstract

Free-floating thrombus (FFT) of the internal carotid artery, which is almost always symptomatic and is usually discovered by ultrasound or angiography performed after a transient cerebrovascular event, is a highly uncommon diagnosis. Here, we report a case of an asymptomatic freefloating internal carotid artery thrombus most probably caused by an atherosclerotic plaque rupture. It was detected by carotid ultrasound and was treated with eversion endarterectomy without any neurologic complications. Six weeks after surgery, the patient is doing well.

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Abstract  

NiMoO4 obtained by calcination of precursors has been shown to be a very effective catalyst for oxidative dehydrogenation of propane into propene. Preparation conditions and thermal decomposition of two precursors have been studied by TG-DTA, HTXRD, FFT-IR, and thermo-desorption coupled to mass spectroscopy in order to determine their composition and to define the best treatment to favour the oxidative dehydrogenation process. The selectivity and activity for propane transformation into propene are very different depending on the nature of the precursor and of the active phases obtained after thermal activation. The more selective high-temperature β phase of NiMoO4 has been obtained at a lower temperature (500°C) than previously reported (700°C).

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19-channel-EEGs were recorded from scalp surface of 30 healthy subjects (16m, 14f, mean age: 34 ys, SD: 11.7 ys) at rest and under IPS (Intermittent Photic Stimulation) at rates of 5, 10 and 20 Hertz (Hz). Digitalized data underwent spectral analysis with fast fourier transformation (FFT) yielding the basis for the computation of global field power (GFP). For quantification GFP values in the frequency ranges of 5, 10 and 20 Hz at rest were divided by the corresponding data gained under IPS. While ratios from PDE data showed no stable parameter due to high interindividual variability, ratios of alpha-power turned out to be uniform in all subjects: IPS at 20 Hz always led to a suppression of alpha-power. Dividing alpha-GFP at rest by alpha-GFP under 20-Hz IPS thus resulted in a ratio <1. We conclude that ratios from GFP data are a stable diagnostic paradigma.

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Abstract  

A small scale (100 mL) calorimeter is developed. It includes a glass vessel submerged in a thermostatic bath, a compensation electrical heater, and a control system. The typical operation mode consists on introducing the solvents and part of the reactants into the vessel, to stabilise a temperature of the bath (T j) some degrees below the desired process temperature (T p) and to adjust the reaction mass temperature (T r) to T p using the electrical heater. An oscillating set point is established for Tr, which produces an oscillating response of the applied compensation power (Q c). Finally, the rest of reactants are dosed to the vessel. A small deviation of T r and T p is observed. Even though it can be avoided improving the tuning of the controller, it can be useful for enhancing the calculation of the heat capacity of the reaction mixture (C P). The signals of T r, Q c and T j are processed on-line using the FFT (Fast Fourier Transform) method as the mathematical tool used to analyse the data obtained, producing accurate values of the heat evolved (Q c) by the process, the heat transfer coefficient (UA), and the heat capacity of the reaction mixture (C P).

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Central leader and vase form tree models were built using Finite Element Modelling (FEM). Their main characteristics were chosen to be the same. To get comparable results to real values, acceleration versus time curves of the two types of real trees were processed using FFT method to determine their natural frequencies. The natural frequencies measured on real trees and calculated for the models have shown good similarity. The models were virtually exposed to the effect of horizontal forced vibration in the frequency range of 0–20 Hz. Acceleration-frequency curves were calculated and drawn to find the best frequency values for the highest accelerations and also to see their differences in the limb. For the same purpose, the direction of shaking was also changed. It was found that for the central leader limb shape multidirectional shaking would bring uniform detachment, while for the vase form trees, even the unidirectional shakers are appropriate. Real trees were also shaken and their acceleration-frequency curves were compared with the values of the FEMs. The resultant good similarity proves the ability of the models. The acceleration values achieved in the vase form models were much higher than for the central leader type. The acceleration-frequency curve of the shaker unit can be used to find the best frequency for shaking.

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Acta Physiologica Hungarica
Authors:
T Yano
,
R Afroundeh
,
K Shirakawa
,
C-S Lian
,
K Shibata
,
Z Xiao
, and
T Yunoki

The purpose of the present study was to examine how oscillation of tissue oxygen index (TOI) in non-exercising exercise is affected during high-intensity and low-intensity exercises. Three exercises were performed with exercise intensities of 30% and 70% peak oxygen uptake (Vo2peak) for 12 min and with exercise intensity of 70% Vo2peak for 30 s. TOI in non-exercising muscle (biceps brachii) during the exercises for 12 min was determined by nearinfrared spectroscopy. TOI in the non-exercising muscle during the exercises was analyzed by fast Fourier transform (FFT) to obtain power spectra density (PSD). The frequency at which maximal PSD appeared (Fmax) during the exercise with 70% Vo2peak for 12 min (0.00477 ± 0.00172 Hz) was significantly lower than that during the exercise with 30% Vo2peak for 12 min (0.00781 ± 0.00338 Hz). There were significant differences in blood pH and blood lactate between the exercise with 70% Vo2peak and the exercise with 30% Vo2peak. It is concluded that TOI in nonexercising muscle oscillates during low-intensity exercise as well as during high-intensity exercise and that the difference in Fmax between the two exercises is associated with the difference in increase in blood lactate derived from the exercise.

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. Korn, G. A. – Korn, T. M.: Matematikai lézikönyv műszakiaknak . Műszaki Könyvkiadó, Budapest 1975. Ramirez, R. W.: The FFT: Fundamentals and Concepts . Prentice-Hall, Englewood Cliffs, NJ, USA 1985.

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