scholarly journals Characterization of aggregates by the speed of sound waves and densitometry

1993 ◽  
Vol 03 (C1) ◽  
pp. C1-27-C1-38
Author(s):  
O. GLATTER
Keyword(s):  
2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Vicente Torres-Zúñiga ◽  
Rosalba Castañeda-Guzmán ◽  
Santiago J. Pérez-Ruiz ◽  
Omar G. Morales-Saavedra

Different thermoelastic parameters, for example, the acoustic attenuation and the speed of sound, are fundamental for instrumental calibration and quantitative characterization of organic-based dissolutions. In this work, these parameters as functions of the concentration of an organic dye (crystal-violet: CV) in distillated water (H2O) based dissolutions are investigated. The speed of sound was measured by the pulsed-laser photoacoustic technique (PLPA), which consists in the generation of acoustic-waves by the optical absorption of pulsed light in a given material (in this case a liquid sample). The thermally generated sound-waves traveling through a fluid are detected with two piezoelectric sensors separated by a known distance. An appropriate processing of the photoacoustic signals allows an adequate data analysis of the generated waves within the system, providing an accurate determination of the speed of sound as function of the dye-concentration. The acoustic attenuation was calculated based on the distance of the two PZT-microphones to an acoustic-source point and performing linear-fitting of the experimental data (RMS-amplitudes) as function of the dye-concentration. An important advantage of the PLPA-method is that it can be implemented with poor or null optical transmitting materials permitting the characterization of the mechanical and concentration/aggregate properties of dissolved organic compounds.


A theory is presented for deriving the speed of sound and wind velocity as a function of height in the upper atmosphere from observations on the travel times of sound waves from accurately located grenades, released during rocket flight, to microphones at surveyed positions on the ground. The theory is taken to a second order of approximation, which can be utilized in practice if lower atmosphere (balloon) measurements are available. By means of the gas law and the vertical equation of motion of the atmosphere, formulae are obtained for deriving temperature, pressure and density from the speed-of-sound profile, and these also may be evaluated to a higher accuracy if lower atmosphere measurements are available. An outline is given of the computational procedure followed in the processing of data on the basis of this theory by means of the Pegasus computer. Methods of calculating the correction to travel times due to the finite wave amplitude are discussed and compared, and the effect of neglecting this correction in a particular set of experimental data is examined. Other errors which may affect the determination of pressure are also discussed. Consistency between the theory and experimental data obtained in 13 Skylark rocket flights at Woomera is checked in two ways: by examining least squares residuals associated with the sound arrivals at various microphones; and by treating the vertical component of air motion as unknown and examining its distribution about zero. The reduction in the least squares residuals which occurs when account is taken of second order terms is evaluated on the basis of these sets of experimental data.


2005 ◽  
Vol 20 (27) ◽  
pp. 6298-6306 ◽  
Author(s):  
PAOLO BENINCASA

Gauge/string correspondence provides an efficient method to investigate gauge theories. In this talk we discuss the results of the paper (to appear) by P. Benincasa, A. Buchel and A. O. Starinets, where the propagation of sound waves is studied in a strongly coupled non-conformal gauge theory plasma. In particular, a prediction for the speed of sound as well as for the bulk viscosity is made for the [Formula: see text] gauge theory in the high temperature limit. As expected, the results achieved show a deviation from the speed of sound and the bulk viscosity for a conformal theory. It is pointed out that such results depend on the particular gauge theory considered.


2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Jin-Hyuk Lee ◽  
Per G. Reinhall ◽  
Hwan-Sik Yoon

A biomimetic miniature underwater acoustic sensor is proposed and analyzed for the measurement of directivity of underwater sound propagation. Unlike a hydrophone array, which detects propagation direction by the arrival time of sound waves, this novel sensor is based on a mechanically coupled mechanism, which amplifies the time delay of the arriving sound wave. In this paper, a mathematical model of the sensor is developed based on the finite element (FE) modeling technique, and it is used to study performance characteristics of the sensor. Effects of the fluid–structure interaction are examined through simulation of the sensor model and the results are compared with those obtained by a full scale FE model developed in a commercial software package.


2003 ◽  
Vol 107 (2) ◽  
pp. 306-320 ◽  
Author(s):  
Peter R. Birkin ◽  
Timothy G. Leighton ◽  
John. F. Power ◽  
Matthew D. Simpson ◽  
Aurore M. L. Vinçotte ◽  
...  

Author(s):  
Niurka Chaveli Castro Chavelas ◽  
Elizabeth Hernandez-Marin ◽  
Gustavo Contreras-Martínez

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
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...  

Density (ρ), speed of sound (U), and the derived magnitudes of two diethylmethylammoniumionic liquids (ILs) against temperature have been studied in this work. The chosen ILs were diethylmethylammonium trifluoromethanesulfonate [C2C2C1N][OTf] and diethylmethylammonium methanesulfonate [C2C2C1N][MeSO3]. In order to analyze the influence of water content, saturated and dried samples of these ILs were studied. The ILs were dried using a vacuum pump, and the saturation level (28% and 6% in weight for [C2C2C1N][MeSO3] and [C2C2C1N][OTf], respectively) was achieved by keeping the ILs in an open bottle at ambient temperature. Direct measurements of density and speed of sound were taken with an Anton Paar DSA 5000. Linear equations were used to express the correlation of both properties with temperature, and the thermal expansion coefficient, αp, and the adiabatic bulk modulus constant, KS, have been also obtained. Additionally, results were compared with previous literature data in order to have a deeper understanding of the liquid properties and detect possible anomalous behaviors. The effect of water content is different on both properties. Thus, the density of the samples slightly increases when water is removed, whereas the opposite behavior was found with regard to the speed of sound, which decreased when the water content was completely removed.


2020 ◽  
Vol 3 (10) ◽  
Author(s):  
Y. Aytemiz

Building a musical instrument requires precise calculations of the positions of its holes to obtain desired notes. To make these calculations, sound waves should be examined. Sound is a longitudinal wave and has five distinguishing aspects: amplitude, frequency, wavelength, period, and speed. A note is characterized by the frequency of the wave. In this experiment, the frequencies of notes and the speed of sound in air is used to calculate the length of a closed-end tube needed to obtain that frequency. Then, these values of lengths are used to create sound and the frequencies are measured with a tuner. The water level is changed until the desired frequency is reached. Then, a graph of length and 1/frequency is drawn to experimentally determine the slope, from which a function of length of tube is written in terms of frequency. With this equation, length required for any note can be calculated. 


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