Sound Velocity Data Research Articles

Combined in situ synchrotron X-ray diffraction and ultrasonic interferometry study of ϵ-FeSi at high pressure

Ultrasonic interferometry was used in combination with synchrotron X-radiation to determine the compressional and shear wave velocities and unit-cell volumes of ϵ-FeSi (cubic B20 structure) at room temperature and pressures up to ∼12 GPa. The data collected during compression are compared with those collected during decompression after heating to release stress within the sample cell. By fitting all of the decompression unit-cell volume and sound velocity data to third-order finite-strain equations, we obtain the adiabatic zero-pressure bulk and shear moduli and their first pressure derivatives: K S0=169.3 (8) GPa, G 0=116.3 (4) GPa, K′S0=6.5(3), G′0=3.0(1). The bulk modulus obtained from this study is in good agreement with those of some previous experimental studies, but significantly lower than those obtained by first-principle calculations. This study presents the first direct measurement on the shear properties of this phase.

Development of in situ Brillouin spectroscopy at high pressure and high temperature with synchrotron radiation and infrared laser heating system: Application to the Earth's deep interior

Seismic wave velocity profiles in the Earth provide one of the strongest constraints on structure, mineralogy and elastic properties of the Earth's deep interior. Accurate sound velocity data of deep Earth materials under relevant high-pressure and high-temperature conditions, therefore, are essential for interpretation of seismic data. Such information can be directly obtained from Brillouin scattering measurement. Here we describe an in situ Brillouin scattering system for measurements at high pressure and high temperature using a laser heated diamond anvil cell and synchrotron radiation for sample characterization. The system has been used with single-crystal and polycrystalline materials, and with glass and fluid phase. It provided high quality sound velocity and elastic data with X-ray diffraction data at high pressure and/or high temperature. Those combined techniques can potentially offer the essential information for resolving many remaining issues in mineral physics.

Dispersion relation for air via Kramers-Kronig analysis

A general expression for the dispersion of acoustic waves in air is obtained by combining the attenuation coefficient given by the ISO:9613-1 standard and the twice-subtracted Kramers-Kronig relation. Good agreement is found with published data of sound velocity at different frequencies and relative humidities. The resulting expression is used to investigate changes in local dispersion with temperature and humidity.

Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied.

Behavior of aluminum shear modulus in solid-liquid mixed phase: Estimation with percolation theory

The variation of aluminum shear modulus with the melting-mass fraction in the solid-liquid mixed phase has been estimated by the percolation theory. With the total number of calculated sites from 0.125×106 to 8.0×106, it is shown that there are two critical points corresponding to the melting-mass fraction 0.313 and 0.687, respectively. At the critical point 0.313, the longitudinal sound velocity begins to attenuate to bulk sound velocity and completely attenuates to bulk sound velocity at the critical point 0.687. This is in accord with previous independent and our sound velocity data of aluminum in the solid-liquid phase, and suggests a different interpretation of shock sound speed data for melt mass fraction.

Acoustic phenomena in porous media studied by transient grating spectroscopy: a critical test of the Biot theory

The propagation of sound in a porous solid filled by a liquid can be described by a phenomenological model introduced by M. A. Biot, that is still extensively used to predict the essential acoustic properties of a wide variety of porous media. Nevertheless testing of the Biot theory at ultra/hypersonic frequencies and in porous media with nanometric scale heterogeneities remains an open issue. We studied the propagation of acoustic waves in two liquid-filled porous glasses by heterodyne detected transient grating experiments [1]. A test of the Biot theory is presented under two new regimes, namely, for a new frequency range up to 1.3 GHz and for porous media with nanometric scale heterogeneities [2]. We show that the Biot theory describes the sound velocity data correctly, but does not account for the acoustic attenuation. We suggest that the acoustic damping is mainly due to the dissipation mechanisms intrinsic of the matrix and the liquid which are not accounted for in the theory. [1] Time-resolved spectroscopy of complex liquids, edited by Torre R. (Springer, New York) 2008. [2] A. Taschin, R. Cucini, P. Bartolini, R. Torre, Europhys. Lett. In press.

Time-Resolved Spectroscopy of Water confined in Vycor

We present measurements on water confined in Vycor 7930 by heterodyne-detected transient grating experiments (HD-TG) [1]. We studied the acoustic wave propagation, the thermal diffusion and the liquid viscous flow through the pores as a function of temperature (-15 - 90 °C) and of the exchanged q-vector (0.63 - 2.5 μm-1). The data show interesting aspects due partly to the confinement effects and partly to the peculiarities of bulk water. Acoustic results are compared with the predictions of the Biot theory finding a good agreement only for the sound velocity data, while the predictions for the acoustic wave attenuation is poor as just reported in [2]. Our technique is able to induce a thermal grating inside the sample. The analysis of the data requires an extension of the Biot theory, that takes into account the temperature variations. Surprisingly, our data show that the acoustic oscillation are not affected by the temperature. The induced thermal grating is also used to analyze the viscous flow of water inside the pores and the thermal diffusion. [1] Time-resolved spectroscopy of complex liquids, edited by Torre R. (Springer, New York) 2008 [2] A. Taschin, R. Cucini, P. Bartolini, R. Torre, Europhys. Lett., in press.

Investigation of structural changes near the critical point in liquid Ga-Pb alloys using an acoustic method

The anomalous temperature dependence of the sound velocity above the liquid-liquid coexistence curve in the Ga-Pb system is associated with the critical fluctuations. A fit of the Fixman theory of the sound velocity data at the critical composition allows determination of the correlation length ξ On the other hand, the temperature dependence of ξ of the alloy with critical composition can be calculated in frames of the two-scale-factor universality hypothesis using interfacial tension data. Recently we proposed a new method of extracting the values of the liquid-liquid interfacial tension and densities of contacting phases along the coexistence curve from the results of acoustic measurements. The correlation length values determined from the sound velocity and interfacial tension measurements are in a good agreement to each other and in a reasonable agreement with the results of small-angle scattering experiments. All the critical exponents are determined by two exponents only, β and μ, which can be obtained from the coexistence curve, density and interfacial tension data.

Volumetric, isentropic compressibility and electrical conductivity of solutions of tri-sodium phosphate in 1-propanol + water mixed-solvent media over the temperature range of 283.15–303.15 K

Density, sound velocity and electrical conductivity of solutions of tri-sodium phosphate (Na 3PO 4) in 1-propanol + water mixed-solvent media with alcohol mass fractions of 0.00, 0.05, 0.10, and 0.15 are reported in the 283.15–303.15 K temperature range at 5 K intervals. From the experimental density and sound velocity data, the apparent molar volume and isentropic compressibility values of tri-sodium phosphate are evaluated and fitted to a Redlich + Meyer type equation from which the apparent molar volume and apparent molar isentropic compressibility of the solutions at the infinite dilution are calculated at working temperature. The results show a positive transfer volume of Na 3PO 4 from an aqueous solution to an aqueous 1-propanol solution. The apparent molar isentropic compressibility of Na 3PO 4 in aqueous 1-propanol solutions is negative and it increases with increasing concentration of Na 3PO 4, 1-propanol and temperature. The effects of the electrolyte concentration, temperature and relative permittivity of the medium on the molar conductivity are also investigated. Comparisons between the results obtained in this work are made with those for Na 2HPO 4 and NaH 2PO 4 obtained in our previous works.

Study of acoustical properties of supercritical carbon dioxide using liquid acoustical theory

Molar sound velocity, molar adiabatic compressibility and Van der Waals constant of gaseons, liquid and supercritical carbon dioxide at different temperature and pressure are calculated using liquid acoustical models and data of sound velocity, density, molar volume and adiabatic compressibility of carbon dioxide provided by National Institute of Standards and Technology, USA. The results show that the liquid acoustical models can be used in study acoustical property of supercritical carbon dioxide in wide ranges of temperature and pressure. The surface tension, conglutination and diffusivity at different temperatures and pressures are calculated. And the mutative rules of these physical quantities are analyzed. The data can provide reference for supercritical liquid technique.

Excess molar volumes and ultrasonic studies of dimethylsulphoxide with ketones at T = 303.15 K

Excess molar volumes ( V E) and ultrasonic sound velocities at T = 303.15 K and ambient pressure have been measured as a function of composition for the binary liquid mixtures of dimethylsulphoxide (DMSO) with ketones. The ketones studied in the present investigation include ethyl methyl ketone (EMK), diethylketone (DEK), methyl propyl ketone (MPK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The V E values were measured using a dilatometer and were positive over the entire mole fraction range for all systems except in the binary system DMSO with EMK where the V E exhibits an inversion in sign. The experimental V E values have been correlated using Redlich–Kister and Hwang et al. equations. The ultrasonic sound velocities for the above systems have been measured with a single crystal interferometer at a frequency of 3 MHz. The sound velocity ( u) data have been used to calculate isentropic compressibility ( K s) and deviation in isentropic compressibility (Δ K s) over the entire range of volume fraction. The sound velocity data have been predicted in terms of free length theory (FLT), collision factor theory (CFT), and Nomoto relation. The results reveal that all the theories gave a satisfactory estimate of the sound velocity. The deviations in values of isentropic compressibility (Δ K s) were negative over the entire range of volume fraction in all the binary liquid mixtures. The results are interpreted with respect to possible molecular interactions between components.

Studying the transfer process of a gemini surfactant from water to β-cyclodextrin at a molecular level

A thermodynamic study of a gemini type surfactant, bis(dodecyl dimethylammonium)diethyl ether dibromide (12-EO 1-12), has been carried out in water and in the presence of β-cyclodextrin (β-CD) at 298 K. Density and sound velocity data for the aqueous solution of the gemini in both systems were analyzed to calculate the molar apparent and partial volumes and adiabatic compressibilities. For the ternary system, the shift of the critical micelle concentration and the values of the transfer properties prove the formation of a molecular complex with a predominantly 1:2 stoichiometry (one surfactant molecule per two CDs).

Apparent molar volume, isentropic compressibility and conductivity of di-sodium hydrogen phosphate in water and in aqueous solutions of 1-propanol

Precise measurements on the density and sound velocity of solutions of di-sodium hydrogen phosphate in 1-propanol + water mixed-solvent media with alcohol mass fractions of 0.00, 0.05, 0.10 and 0.15 are reported in the 283.15–303.15 K temperature range at 5 K intervals. Electrical conductivity and refractive index of the solutions are studied at 298.15 K. From the experimental density and sound velocity data, the apparent molar volume and isentropic compressibility values of di-sodium hydrogen phosphate have been evaluated. The results show a positive transfer volume of di-sodium hydrogen phosphate from an aqueous 1-propanol solution to a more concentrated 1-propanol solution. The apparent molar isentropic compression of di-sodium hydrogen phosphate in aqueous 1-propanol solutions is negative and it increases with increasing the concentration of 1-propanol and temperature. The negative values of apparent molar isentropic compression imply that the water molecules around the di-sodium hydrogen phosphate are less compressible than the water molecules in the bulk solutions. The effects of the electrolyte concentration and relative permittivity of the medium on the molar conductivity were also investigated.

Volumetric properties of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B 1) in dilute HCl and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K

Apparent molar volumes and apparent molar isentropic compressibilities of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B 1) were determined from accurately measured density and sound velocity data in water and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K. These volume and compressibility data were extrapolated to zero concentration using suitable empirical or theoretical equations to determine the corresponding infinite dilution values. Apparent molar expansibilities at infinite dilution were determined from slopes of apparent molar volume vs. temperature plots. Ionization of both ascorbic acid and thiamine hydrochloride were suppressed using sufficiently acidic solutions. Apparent molar volumes at infinite dilution for ascorbic acid and thiamine hydrochloride were found to increase with temperature in acidic solutions and in the presence of co-solute, NaCl. Apparent molar expansibility at infinite dilution were found to be constant over the temperature range studied and were all positive, indicating the hydrophilic character of the two vitamins studied in water and in the presence of co-solute, NaCl. Apparent molar isentropic compressibilities of ascorbic acid at infinite dilution were positive in water and in the presence of co-solute, NaCl, at low molalities. Those of thiamine hydrochloride at infinitive dilution were all negative, consistent with its ionic nature. Transfer apparent molar volumes of vitamins at infinite dilution from water solutions to NaCl solutions at various temperatures were determined. The results were interpreted in terms of complex vitamin–water–co-solute (NaCl) interactions.

Thermal and transport properties of manganites [formula omitted] ( [formula omitted], 0.45)

The temperature dependencies of the specific heat, thermal diffusivity and thermal conductivity in polycrystalline Nd 0.55 Sr 0.45 MnO 3 and Nd 0.5 Sr 0.5 MnO 3 manganites are measured in wide temperature range of 77–300 K. These characteristics reveal peculiarities at magnetic phase transition and transition into charge-ordered (CO) state. It is shown that a change of the phonon spectrum due to lattice contraction is the main reason of a sharp decrease of the thermal conductivity in Nd 0.5 Sr 0.5 MnO 3 at the transition to the antiferromagnetic CO state. Using the experimental thermal diffusivity data and sound velocity data a temperature dependency of the phonon mean free path is calculated.

Predicting hydrate stability zones of petroleum fluids using sound velocity data of salt aqueous solutions

Predicting hydrate stability zones of petroleum fluids from the aqueous phase properties can have a practical application as measuring these properties is normally easier than hydrate phase equilibrium measurement and can reduce experimental costs and efforts. In this work, the possibility of estimating hydrate stability zone from sound velocity data of salt aqueous solutions is investigated using a feed-forward artificial neural network method with a modified Levenberg–Marquardt algorithm. The method considers the changes of sound velocity in salt (NaCl, KCl, NaBr, KBr, BaCl 2, MgCl 2, Na 2SO 4, HCOONa) aqueous solution with respect to sound velocity in pure water and therefore there is no need to have a quantitative analysis of the aqueous solution. Independent data (not used in training and developing of the method) are used to examine the reliability of this tool. The predictions of this method are in acceptable agreement with independent experimental data, demonstrating the reliability of this tool for estimating the hydrate stability zone in the presence of salt aqueous solutions.

Volumetric, Ultrasonic and Transport Properties of Binary Liquid Mixtures Containing Dimethyl Formamide at 303.15 K

AbstractExcess volumes (VE), ultrasonic velocities (u), isentropic compressibility (ΔKs) and viscosities (η) for the binary mixtures of dimethyl formamide (DMF) with 1,2‐dichlorobenzene, 1,3‐dichlorobenzene, 1,2,4‐trichlorobenzene, o‐chlorotoluene, m‐chlorotoluene, p‐chlorotoluene, o‐nitrotoluene and m‐nitrotoluene at 303.15 K were studied. Excess volume data exhibit an inversion in sign for the mixtures of dimethyl formamide with 1,2‐ and 1,3‐dichlorobenzenes and the property is completely positive over the entire composition range for the mixtures of dimethyl formamide with 1,2,4‐trichlorobenzene, o‐nitrotoluene and m‐nitrotoluene. On the other hand, the quantity is negative for the mixtures of dimethyl formamide with chlorotoluenes. Isentropic compressibility (Ks) has been computed for the same systems from precise sound velocity and density data. Further, deviation of isentropic compressibility (ΔKs) from ideal behavior was also calculated. ΔKs values are negative over the entire volume fraction range in all the binary mixtures. The experimental sound velocity data were analysed in terms of Free Length Theory (FLT) and Collision Factor Theory (CFT). The viscosity data were analysed on the basis of corresponding state approach. The measured data were discussed on the basis of intermolecular interactions between unlike molecules.

Ultrasonic velocities and isentropic compressibilities of N-methyl-2-pyrrolidone with ketones and branched alcohols at 303.15 K

The ultrasonic sound velocities and densities are measured for the binary mixtures of N-methyl-2-pyrrolidone (NMP) with ketones and branched alcohols at 303.15 K. The ketones include methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone. The branched alcohols include 2-propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 2-butanol and 2-methyl-2-propanol. The ultrasonic sound velocity data were used to compute isentropic compressibilities (k s). The deviations in the value of k s from ideal value were computed. Except cyclohexanone all the binary mixtures formed by NMP with ketones at 303.15 K exhibit negative deviation from ideal behaviour over the entire range of composition. Cyclohexanone with NMP exhibit positive deviation over the entire range of composition. An inversion in the sign of Δk s from positive to negative was observed for 2-propanol system and negative deviation was observed in four binary mixtures formed by NMP with other branched alcohols at 303.15 K. The ultrasonic sound velocities of these mixtures have been analysed is terms of Free Length Theory (FLT), Collision Factor Theory (CFT) and Nomoto's relation.

Modification to the Newton-Laplace formula of sound velocity at high pressure

The Newton-Laplace (NL) formula of sound velocity is shown being invalid at high pressure, and a modified formula is derived based on the Rankine-Hugoniot relations. The derivation shows that the transmission of sound should be a process satisfying the energy conservation condition instead of the adiabatic condition in the NL formula. The agreement of equations of state for metallic liquids deduced from sound velocity data through the modified formula with the direct experimental P-V data is evidently improved as compared with that deduced through the NL formula.

Isothermal compressibility and internal pressure studies of some non-electrolytes in aqueous solutions at low temperatures

The experimental data of density ( ρ) and sound velocity ( u) in the temperature range (275.15 to 293.15) K have been obtained for the systems (dioxane + water), (dimethylformamide + water), (tetrahydrofuran + water), and (acetonitrile + water). The specific heat ( C p ) data for the above systems have been obtained at T = 279.15 K. The data obtained are used to calculate the derived parameters of adiabatic compressibility ( β S), at T = 275.15 K to T = 283.15 K, isothermal compressibility ( β T), and internal pressure ( P i) at T = 279.15 K for different concentrations. The solute properties: apparent molar volume ( ϕ V), apparent molar expansivity ( ϕ E), and apparent molar compressibility ( ϕ KS) have been studied and the limiting values for these properties are reported. The variation in apparent molar properties with concentration and the corresponding temperature and pressure effects are discussed in terms of hydrophobic hydration (–H bonding interaction) and hydrophobic interaction (non-polar group solute–solute association in water). It is noted that the internal pressure of solutions is quite insensitive in the region of solute–solute association, while its variation with concentration in the dilute region is sensitive in contrast to the aqueous alcohol solutions. The molecular interactions also exhibit individualistic behaviour and are much dependent on structural alterations in water structure.