Sound Velocity In Liquids Research Articles

Measurement of High-Frequency Sound Velocity in Mammalian Soft Tissues

A two crystal interferometer for rapid measurement of sound velocity in liquids and soft animal tissues is described. Velocities can be determined to within three parts per thousand with a path length of a few millimeters. The frequencies used are 1, 2, 4, 12, and 36 mc. Temperature is controlled to 0.1°C. A phase comparison method is used for wavelength incorporating dual heterodyne reduction to audio-frequency with presentation as a Lissajous figure on an oscilloscope. Results are given for a few mammalian tissues showing the precision and reproducibility of measurements.

Measurement of Dispersion of Velocity of Sound in Liquids

A technique for the direct measurement of the difference between the velocity of sound in two liquids is described. By choosing for a reference a dispersionless liquid, such as water, the technique becomes a sensitive method for measurement of the change of velocity with frequency in the test liquid. In practice the method is sufficiently sensitive so that changes in the velocity smaller than one part in 104 can be detected. Illustrative measurements are presented for an NaCl solution, sperm oil, and evaporated milk.

A further elucidation of the relationship between sound velocity in liquids and molecular weight

A further elucidation of the relationship between sound velocity in liquids and molecular weight

On Molecular Sound Velocity of Liquids. II Dependence of the Thermal Expansion Coefficient and the Temperature Coefficient of Compressibility of Liquids on the Boiling Point

The coefficient of thermal expansion α and the temperature coefficient of isothermal compressibility (1/β T )(∂β T /∂ T ) p of liquids calculated on the basis of the Lennard-Jones and Devonshire's equation of state as improved by Wentorf, Buehler, Hirschfelder and Curtiss have been shown to be inversely proportional to the boiling point of the liquids, if we consider the liquids at absolute temperatures T =constant× T b , where T b means the boiling points. At temperatures T =0.9 T b , we have theoretically α=0.140/ T b and (1/β T )(∂β T /∂ T ) p =0.865/ T b . If we assume the same temperature dependence for the adiabatic compressibility β s as for β T , we have for the temperature dependence of the sound velocity in liquids (1/ V )(∂ V /∂ T ) p =-0.36/ T b . These lineal dependency of the coefficient of thermal expansion, the temperature coefficient of the adiabatic compressibility, and the temperature coefficient of the sound velocity on the reciprocal of the boiling point have been investigated in many...

On Molecular Sound Velocity of Liquids. I Consideration on the Rao's Relation between the Temperature Coefficient of Sound velocity in and the Coefficient of Thermal Expansion of Liquids

(a) The temperature coefficient of the isothermal compressibility (1/β T )( d β T / d T ) and the coefficient of thermal expansion α have been computed for liquids employing Lennard-Jones and Devonshire's equation of state as improved by Wentorf, Buehler, Hirschfelder and Curtiss and employing the numerical tables by these authors. The computed value of the ratio of these two coefficients is about 6.5 at temperatures corresponding to 0.9 T b , where T b means the boiling points. This gives a rough explanation of the Rao's relation between the temperature coefficient of the adiabatic compressibility β S and the coefficient of thermal expansion α; i.e., (1/β s )( d β s / d T )=7α. (b) Reexamination of Rao's relation has been performed on many organic liquids, some liquified gases, and some molten metals employing existing ultrasonic velocity data. The ratios (1/β s )( d β s / d T ):α are about 7 in organic liquids, about 5 in liquified gases and rather scattered in molten metals.

On Molecular Sound Velocity of Liquids. III Consideration on the Rao's Relation on the Dependence of Molecular Sound Velocity on Critical Constants

(a) Theoretical derivation of the Rao's relation R V = a ( T c / M ) 1/6 v c has been performed on the basis of the Lennard-Jones and Devonshire's liquid model and using Wentorf, Buehler, Hirschfelder and Curtiss' equation of state. Here R V means the molecular sound velocity defined by R V =( M /ρ) V 1/3 , with M the molecular weight, ρ the density and V the sound velocity; T c and v c mean the critical temperature and the critical volume respectively, and a is an empirical constant with average value 2.68, according to Rao. The theoretical value of a obtained in this paper is 4.64. (b) Re-examination of Rao's relation has been performed on organic liquids and on some liquified gases employing existing ultrasonic velocity data and the following average values have been obtained: a exp =2.86 (on five liquified gases), a exp =2.69 (on 21 organic liquids except alcohols, acids and acetonitrile). The a exp for alcohols and acids are somewhat lower, the lowest example being a exp =1.825 for acetic acid. These...

The Measurement of the Velocity of Sound in Liquids

A new technique for the measurement of sound velocity in liquids has been developed, which is especially suited to frequencies in the range from 0.5 to 5 mc. It employs an approximation to the boundary conditions in Guptill's closed form solution for the radiation field between two infinite walls with a piston source in one wall. Measurements have been made in distilled water at 0.6 and 7.6 mc with an error of less than 0.2 percent in the low-frequency measurements. No dispersion is indicated to the order of the experimental error, in the temperature range from 10 to 20°C. A description of the apparatus is given.

Velocity of Sound in Liquids and Molecular Weight

Velocity of Sound in Liquids and Molecular Weight

A Liquid with Unusually High Sound Velocity

During a study of the effect of molecular structure on sound velocity in liquids, a liquid was found in which the velocity of sound is 3000 meters/second at 20°C, as measured by a 3-Mc ultrasonic interferometer. Previously the highest value known was less than 2000 meters/second, for glycerine. The new liquid is a viscous concentrated aqueous solution of sorbitol, prepared by heat dehydration of the commercial syrup “Arlex.” Sorbitol was selected for study, even though it is a solid, because its chemical structure is that of a double glycerine molecule. Concentrated sorbitol solutions also show a dispersion of sound velocity with frequency in the megacycle range (reminiscent of the behavior of polyisobutylene as described by Mason) and absorption coefficients many times larger than that of glycerine.

Velocity of Sound and Molecular Association in Liquids

Two new, empirical criteria for determining molecular association in liquids are pointed out. One is the quantity PCR/TC in which R is a function of the velocity of sound; the other is the ratio of the velocity of sound in a liquid to the velocity of sound in the gas of the same compound. In both cases low numerical values of the ratios are qualitative indicators of association.

Velocity of Sound in Liquids and Chemical Constitution

A study of the recently obtained data on the velocity of sound and density in liquids reveals a simple relation between these quantities namely the law, v⅓M/ρ = R where v is the velocity of sound in the liquid, M the molecular weight, ρ the density and R a constant independent of temperature. It is shown that the velocity of sound cannot be a proper basis of comparison in any homologous series. The result of plotting the constant R against the molecular weight of members of homologous series leads to the equation R = αM + β where α is a general constant and β a characteristic constant for any one homologous series. The difference in R for successive members of homologous series is a constant independent of the series and R is an additive function of the chemical structure. Values of R for hydrogen, carbon, oxygen, bromine, and chlorine are tabulated.

Dispersion of Sound Velocity in Liquids

As is now well known1, the spectral character of monochromatic light scattered by many liquids exhibits an observable change as the result of such scattering; an instrument of sufficiently high resolving power, for example, a Fabry-Perot etalon2, indicates the presence of Doppler-shifted components on either side of the main radiation. From this we are able to infer that sound waves of very high frequency represent a considerable part of the energy of thermal agitation in such liquids. The frequency of the sound-waves actually revealed by this method depends on the wave-length of the incident light, the angle of scattering and the liquid employed; in most actual cases, it lies within the frequency range 1,000–10,000 megacycles per second.

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids

The Velocity of Sound in Liquids