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1

Comparing measurement correction of echo sounder in shallow-water area

Zheng Zhaoyong, Jiang Siyi, Zeng Weizhu

Acta Geophysica

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2022

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Vol. 70, no 4

1677--1686

EN

Error correction of echo sounder is very important for the accurate measurement of water-depth in shallow-water area. There are some issues in measuring the water depth, they are accuracy, resolution, inaccurate beamwidth of transmit and can be solved by the existing methodologies. In this article, comparing measurement is an efficient method for error correction of echo sounder. The most commonly used comparing methods are sounding poles, plumb-lines and thermohaline methods. However, the sounding poles method can only measure the water-depth less than 5 m as its limited by the length of measuring poles; the plumb-lines method cannot guarantee the accuracy of water-depth value as its difficult to determine whether the plumb-line falls vertically onto the water floor or into the underwater sediment; the thermohaline methods is time-consuming as its need lots of the temperature and salinity information for the correction of sound velocity. Based on these knowledge and experience, we put forward a comparator for comparing measurement of water-depth, which could adjust sound velocity of echo sounder for precisely measure actual water-depth of the survey area without complicated thermohaline correction work. The comparator method has practical implications for the quick error correction of echo sounder survey in shallow water area. The experimental results predict that the mistakes are easily caused by the complicated correction work which can be avoided and establishes that the water-depth measurement is more efficient.

2

Mechanical properties and sound velocity of gold copper (AuCu) II superlattice: 3D molecular dynamic (MD) simulation

Aish Mohammed Mahmoud

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 4

901--909

EN

Young’s modulus, yield stress and Poisson’s ratio are studied for different size and tem- perature. The temperature dependence of simulated Young’s modulus is quite similar to experimental results. Transverse sound velocity is estimated from the simulated elastic con- stants at each temperature. The dislocation speed reaches up to 75% of the transverse sound velocity. The dislocation speed decreases with increasing temperature linearly. The tempera- ture dependence of macroscopic deformation behavior and the possibility of the existence of supersonic dislocations are discussed. The transverse sound velocity and rigidity G is calcu- lated from Young’s modulus, Poisson’s ratio and density ρ which changes with temperature.

3

Identification of meat types by ultrasonic methods

Nowak K. W.

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2015

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nr 18(2)

79--84

EN

The ability of identification of meat types using ultrasonic measurement was evaluated in this work. Four types of muscles were analyzed (turkey breast and thigh, and pork loin and ham). Ultrasonic measurements were performed at storage (5 ±1oC) and room (20±1oC) temperatures using the through-transmission technique and differential method of determination of sound velocity and the attenuation coefficient. The mean values of sound velocity for the breast, thigh, loin and ham were respectively: 1550.7, 1536.6, 1558.7, 1559.7 m/s at the storage temperature, and 1582.7, 1578.5, 1596.9, 1592.7 m/s at the room temperature. The mean values of the attenuation coefficient in the same order were: 21.3, 23.2, 30.6, 28.1 m-1 and 22.2, 18.9, 22.0, 22.4 m-1. Statistically significant differences in the sound velocity were observed between pork and turkey muscles, therefore, the meat of those species can be identified based on ultrasound measurements of sound velocity. The attenuation coefficient cannot be applied in the identification of meat types due to absence of significant differences in the mean values.

4

Acoustical Studies of some Chalcones in DMF and DMSO Solutions

Baluja S., Kasundra P.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 44

130--140

EN

This work reports densities, speeds of sound, and isentropic compressibility of the solutions of some synthesized chalcones in N,N-dimethylformamide and dimethyl sulphoxide solutions of various concentrations at 308.15 K with a view to understand molecular interactions in these solutions.

5

Vacancies and changes in the sound velocity in alkali halides on passing through the melting point

Książek K., Górecki T., Górecki C.

Prace Naukowe. Chemia i Ochrona Środowiska / Akademia im. Jana Długosza w Częstochowie

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2005

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Vol. 10

171--176

EN

Basing on the vacancy model of melting, proposed previously by the authors an expression for the ratio of the sound velocity (Debye averages) in the solid Us and liquid UI phases of alkali halides, at their melting points, has been derived. The calculated value of the Us/UI ratio equal to 1,23 (the same for all the alkali halides) satisfactorily agrees with the experimental data available in the literature for 13 alkali halides.

6

An ultrasonic helium leak detector

Bolek W., Jędrusyna A., Wiśniewski T.

Elektronika : konstrukcje, technologie, zastosowania

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2004

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Vol. 45, nr 8-9

247-249

EN

In the paper a novel method for detection of helium content in air is presented. The helium concentration is derived from changes in sound velocity in the gas mixture under test. The sound velocity is calculated by time of flight (TOF) of the ultrasonic burst travelling between two transducers located in known distance. Another approach for sound velocity uses binary frequency shift keyed (BFSK) signals. This method could be also used in measurement of distance. The basic theory concerning relations between helium concentration and sound velocity in ideal gas was also presented.

PL

W pracy przedstawiono opracowaną przez autorów metodę pomiaru zawartości helu w powietrzu. Metoda oparta jest na wyznaczaniu zmian prędkości dźwięku w badanej mieszance gazowej. Prędkość dźwięku wyznaczana jest na podstawie pomiaru czasu przelotu impulsu ultradźwiękowego pomiędzy dwoma przetwornikami ultradźwiękowymi oddalonymi o znaną odległość. Inny wariant układu pomiarowego wykorzystuje sygnały z binarnym kluczowaniem częstotliwości (BFSK). Opisana metoda może być wykorzystywana do pomiaru odległości. W referacie przedstawiono także podstawowe zależności pomiędzy stężeniem helu w mieszance hel-powietrze i prędkością dźwięku.