In this study, the negative pressure values at which inertial cavitation consistently occurs in response to a single, two-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (P cav ) for a single pulse as a function of peak negative pressure ( p − ) followed a sigmoid curve, with the probability approaching one when the pressure amplitude was sufficient. The statistical threshold (defined as P cav  = 0.5) was between p −  = 26 and 30 MPa in all samples with high water content but varied between p −  = 13.7 and >36 MPa in other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p −  = 28.2 megapascals was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at various pressure levels and dimensions of cavitation-induced lesions in tissue.

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Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials

Applicability of the Jouyban-Acree model for calculating absolute viscosity of binary liquid mixtures with respect to temperature and mixture composition is proposed. The correlation ability of the model is evaluated by employing viscosity data of 143 various aqueous and non-aqueous liquid mixtures at various temperatures collected from the literature. The results show that the model is able to correlate the data with an overall percentage deviation (PD) of 1.9+/-2.5%. In order to test the prediction capability of the model, three experimental viscosities from the highest and lowest temperatures along with the viscosities of neat liquids at all temperatures have been employed to train the model, then the viscosity values at other mixture compositions and temperatures were predicted and the overall PD obtained is 2.6+/-4.0%.

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Calculation of the viscosity of binary liquids at various temperatures using Jouyban-Acree model.

In recent years, ionic liquids have increasingly gained importance as green solvents. The potential of these organic salts, which are moisture and air stable at room temperature, for new chemical processes and technologies is beginning to be recognized. Research on the thermophysical properties of ionic liquids and their mixtures form the basis for future applications. In this contribution, densities, refractive indices, speeds of sound and dynamic viscosities of 1-methyl-3-octylimidazolium tetrafluoroborate, [Omim][BF4], the room temperature ionic liquid (IL) in binary mixtures with methanol, ethanol, 1-propanol and 2-propanol were measured at 298.15K and atmospheric pressure. The excess molar volumes and molar refraction, isentropic compressibility and dynamic viscosity changes of mixing have been calculated and were satisfactorily correlated by the Redlich–Kister polynomial.

Physical and Excess Properties for Binary Mixtures of 1-Methyl-3-Octylimidazolium Tetrafluoroborate, [Omim][BF4], Ionic Liquid with Different Alcohols

Dynamic viscosities, densities, and speeds of sound of acetic acid with water, methanol, ethanol, methyl acetate, and ethyl acetate at T = (293.15, 298.15, and 303.15) K have been measured over the whole composition range and at atmospheric pressure along with the properties of the pure components. Excess molar volumes and deviations in isentropic compressibility and viscosity for the binary systems at the above-mentioned temperatures were calculated. These results were fit to the Redlich−Kister equation to determine the fitting parameters and the root-mean-square deviations. The UNIQUAC equation was used to correlate the viscosity experimental data.

Dynamic Viscosities, Densities, and Speed of Sound and Derived Properties of the Binary Systems Acetic Acid with Water, Methanol, Ethanol, Ethyl Acetate and Methyl Acetate at T = (293.15, 298.15, and 303.15) K at Atmospheric Pressure

Densities, viscosities, refractive indices, and speeds of sound at the temperature of 298.15 K and atmospheric pressure are reported for the binary and the miscible ternary mixtures of 2-ethoxy-2-methylpropane, ethanol, and 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid. Excess molar volumes and viscosity, molar refraction, and isentropic compressibility changes of mixing have been calculated from the physical properties. The changes of mixing have been adequately fitted to the Redlich−Kister polynomial.

Volumetric and Viscosity Study for the Mixtures of 2-Ethoxy-2-methylpropane, Ethanol, and 1-Ethyl-3-methylimidazolium Ethyl Sulfate Ionic Liquid

Experimental densities, dynamic viscosities, speeds of sound, and relative permittivities for six binary mixtures of water + alkanediols (propane-1,2- and -1,3-diol and butane-1,2-, -1,3-, -1,4-, and -2,3-diol) were measured across the whole composition range and in the temperature range (298.15 to 338.15) K. The deviations in dynamic viscosities, excess isentropic compressibilities, and deviations in relative permittivities were also calculated and fitted to a Redlich−Kister type equation. The partial molar volumes at infinite dilution for the water in six binary mixtures and the differences in these values among various diol isomers were calculated and examined to ascertain structural information on the water molecules around various diols. The variation of the Kirkwood correlation factor was also examined across the whole composition range of the mixtures.

Densities, Dynamic Viscosities, Speeds of Sound, and Relative Permittivities for Water + Alkanediols (Propane-1,2- and -1,3-diol and Butane-1,2-, -1,3-, -1,4-, and -2,3-Diol) at Different Temperatures

Experimental densities, ρ, viscosities, η, speeds of sound, υ, and relative permittivities, er, for three binary mixtures of water + 2-pyrrolidinone, + 1-methyl-2-pyrrolidinone, and + 1-vinyl-2-pyrrolidinone were measured over the entire composition range and at different temperatures. The variations of ρ, η, and υ with water mole fractions were typical of systems which show large nonidealities. The excess molar volumes, , excess isentropic compressibilities, , and deviations in dynamic viscosities, δη, and relative permittivities, δer, were calculated, and their compositional variation was mathematically represented by a Redlich−Kister type equation. The partial molar volumes of water at infinite dilution, , were calculated from the smoothed values of three binary mixtures at different temperatures. The variation of the Kirkwood correlation factor, gK, was examined across the entire composition range. The analysis of these functions revealed that both hydrophobic and hydrophilic hydrations are responsibl...

Densities, Viscosities, Speeds of Sound, and Relative Permittivities for Water + Cyclic Amides (2-Pyrrolidinone, 1-Methyl-2-pyrrolidinone, and 1-Vinyl-2-pyrrolidinone) at Different Temperatures

Measurements on densities, speeds of sound, viscosities, and relative permittivities for 21 binary mixtures of alkoxyethanols (2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol) + benzene, + toluene, + (o-, m-, and p-) xylenes, + ethylbenzene, and + cyclohexane at different temperatures are reported. The excess molar volumes, excess isentropic compressibilities, deviations in dynamic viscosities, speeds of sound, and relative permittivities have been calculated across the mole compositions. The compositional variation of excess and deviation functions has been expressed in terms of the Redlich−Kister equation.

Densities, Excess Molar Volumes, Viscosities, Speeds of Sound, Excess Isentropic Compressibilities, and Relative Permittivities for CmH2m+1(OCH2CH2)nOH (m = 1 or 2 or 4 and n = 1) + Benzene, + Toluene, + (o-, m-, and p-) Xylenes, + Ethylbenzene, and + Cyclohexane

John George and

Papers

Densities, Dynamic Viscosities, Speeds of Sound, and Relative Permittivities for Water + Alkanediols (Propane-1,2- and -1,3-diol and Butane-1,2-, -1,3-, -1,4-, and -2,3-Diol) at Different Temperatures

Densities, Viscosities, Speeds of Sound, and Relative Permittivities for Water + Cyclic Amides (2-Pyrrolidinone, 1-Methyl-2-pyrrolidinone, and 1-Vinyl-2-pyrrolidinone) at Different Temperatures

Densities, Excess Molar Volumes, Viscosities, Speeds of Sound, Excess Isentropic Compressibilities, and Relative Permittivities for CmH2m+1(OCH2CH2)nOH (m = 1 or 2 or 4 and n = 1) + Benzene, + Toluene, + (o-, m-, and p-) Xylenes, + Ethylbenzene, and + Cyclohexane