Ultrasonic Velocity Values Research Articles

W0501-(2) MR流体中の超音波伝播特性(【W0501】電磁場に応答する機能性流体研究の最先端,ワークショップ)

Rheological properties of magnetorheological (MR) fluid were influenced by the cluster formation. The cluster formation appears when an external magnetic field is applied in MR fluids. Hence, we propose an experimental analysis of these structures by measuring properties of ultrasonic wave propagation precisely. The ultrasonic technique can be applied to an opaque fluid, such as MR fluid. The ultrasonic propagation velocity can be found by the pulsation methods. Based on these results, the clustering structures of these fluids are analyzed experimentally in term of temperature, effect of the external magnetic field and hysteresis phenomena. The absolute value of ultrasonic propagation velocity decreases as the volume fraction of particles increases when no magnetic fields. Hysteresis on MR fluids always comes back to the initial value. This occurrence is caused by the clusters formation that is proportional to magnetic field intensity. It seems that cluster formation in MR fluids becomes to the initial condition after the external magnetic field intensity is zero.

Acoustical Properties of Binary Mixtures of Heptane with Ethyl Acetate or Butyl Acetate

AbstractMixed solvents rather than single pure liquids are of utmost practical importance in chemical and industrial processes as they provide an ample opportunity for the continuous adjustment of desired properties of the medium. Therefore, ultrasonic velocity (u) and density (ρ) were measured for the binary mixtures formed by heptane with ethyl acetate or butyl acetate at temperatures 293, 298 and 303 K over the entire composition range. Deviation in ultrasonic velocity (Δu), deviation in isentropic compressibility (Δκs), and excess intermolecular free length (LEf) have been evaluated using the ultrasonic velocity data and the computed results were fitted to the Redlich‐Kister polynomial equation. The values of Δu, Δκs and LEf were plotted against the molar fraction of heptane. The observed positive and negative values of excess parameters were discussed in terms of molecular interaction between the components of the mixtures. Experimental values of ultrasonic velocity and density were compared with the results obtained by theoretical estimation procedures. The results were discussed in terms of average absolute deviation (AAD).

Physical Properties of Binary Mixtures of Ethyl Formate with Benzene, Isopropyl Benzene, Isobutyl Benzene, and Butylbenzene at (303.15, 308.15, and 313.15) K

Densities, viscosities, and speeds of sound of binary mixtures of ethyl formate with benzene, isopropyl benzene, isobutyl benzene, and butylbenzene have been measured over the entire range of composition, at (303.15, 308.15, and 313.15) K and at atmospheric pressure. The excess volume, VE, deviation in viscosity, Δη, and deviation in isentropic compressibility, ΔKs, have been calculated from the experimental values of density, viscosity, and ultrasonic velocity. The excess volumes are positive, while the deviations in viscosities are negative for all of the studied binary systems over the whole composition range. The deviation in isentropic compressibility shows both positive and negative deviations for ethyl formate with benzene and isopropyl benzene, and for the remaining systems they are positive. The ability of some of the empirical models to calculate mixing viscosities was also tested.

Direct measurement of acoustic impedance in liquids by a new pulse echo technique

For the first time a novel experimental technique has been used for direct evaluation of acoustic impedance of liquids. Till date researchers have been using ultrasonic velocity and density measurements to compute acoustic impedance and thermodynamic parameters, which are then used to investigate the nature of molecular interactions of solvent molecules in binary, ternary and quaternary liquid mixtures. Evaluation of acoustic impedance directly is a step in minimizing the cumbersome process of measuring velocities and densities separately of solutions having different mole fraction concentration. Acoustic impedances of ten pure polar and non polar solvents have been determined at different temperatures of 298K, 303K and 308K. This is further coupled with inline simultaneous determination of ultrasonic velocities of the solvents. In order to establish the new method, results have been discussed by comparing the calculated ultrasonic velocity from the experimental acoustic impedance, ultrasonic velocity determination by delay time of flight and the literature values of ultrasonic velocity of the pure solvents.

Effect of frequency on acoustic parameters in a binary mixture of polar liquids

The densities (α) and ultrasonic velocities (C) of binary mixtures of a polar liquid like acetone and toluene have been measured at different frequencies (lMHz, 3MHz and 5MHz) over the entire range of mole fraction of acetone at temperature 303.16k. The intermolecular free length (Lf), isentropic compressibility (β), acoustic impedance (Z), excess values of isentropic compressibility (βE) and acoustic impedance (ZE) have been computed using values of ultrasonic velocity (C) and density (α). The ultrasonic velocity (C), intermolecular free length (Lf) and excess values of isentropic compressibility are positive whereas excess values of acoustic impedance is negative for the entire composition range which indicates the specific interaction between unlike molecules. The results are discussed in the light of intermolecular interactions occurring in the solutions.

Measuring the acoustic wave velocity and sample thickness using an ultrasonic transducer array

We suggest a new method for determining the longitudinal and transverse acoustic wave velocities and sample thicknesses, which is based on the measurement and analysis of pulsed echo signals by an array of ultrasonic transducers. Analytical expressions relating the delay of signals detected by the array and the values of parameters to be determined are obtained within the framework of a ray model of the measuring system. Measurements on a reference sample have been performed. The values of ultrasonic wave velocities and sample thickness obtained using the proposed technique agree with the results of measurements using independent methods.

Molecular Interaction Studies in Binary Liquid Mixtures from Ultrasonic Data

Ultrasonic velocities and densities of the binary liquid mixtures of dimethy1 sulphoxide (DMSO) with phenol, o‐cresol, m‐cresol, p‐cresol and p‐chlorophenol at 318.15 K, over the entire composition range were measured. The theoretical values of ultrasonic velocity were evaluated using the Nomoto’s Relation (NR), Ideal Mixture Relation (IMR), Free Length Theory (FT) and Collision Factor Theory (FLT). The validity of these relations and theories was tested by comparing the computed sound velocities with experimental values. Further, the molecular interaction parameter (α) was computed by using the experimental and the theoretical ultrasonic velocity values. The variation of this parameter with composition of the mixtures has been discussed in terms of molecular interaction in these mixtures.

Ultrasonic Velocities and Densities of l-Histidine or l-Glutamic Acid or l-Tryptophan or Glycylglycine + 2 mol·L−1 Aqueous KCl or KNO3 Solutions from (298.15 to 323.15) K

Ultrasonic velocity and density values of l-histidine or l-glutamic acid or l-tryptophan or glycylglycine + 2 mol·L−1 aqueous KCl or 2 mol·L−1 aqueous KNO3 solution have been measured as functions of amino acid or dipeptide concentration and temperature from T = (298.15 to 323.15) K. Using ultrasonic velocity and density data, the thermodynamic parameters isentropic compressibility (κs) and change in isentropic compressibility values have been computed. The κs values decrease with an increase in the amino acid/dipeptide concentration as well as with temperature of the systems under investigation. The decrease in κs values with an increase in concentration of amino acid/dipeptide in aqueous solutions of KCl and KNO3 has been ascribed to an increase in the number of incompressible zwitterions in the solutions.

Densities, Sound Speed, and IR Studies of (Methanol + 1-Acetoxybutane) and (Methanol + 1,1-Dimethylethyl Ester) at (298.15, 303.15, 308.15, and 313.15) K

Densities and sound speeds for (methanol + 1-acetoxybutane) and (methanol + 1,1-dimethylethyl ester) have been measured over the entire range of compositions, at temperatures of (298.15, 303.15, 308.15, and 313.15) K and at atmospheric pressure of about 0.1 MPa. From the experimental values of density and ultrasonic velocity, the excess molar volumes VE and deviations in isentropic compressibility Δκs have been calculated. The VE and Δκs are negative for both the binaries studied over the whole composition. FT-IR studies of these mixtures are also carried out at T = 298.15 K.

Ultrasonic and spectroscopic investigations of charge-transfer complexes in ternary liquid mixtures

Charge-transfer complexes formed between iodine ( σ-acceptor) and pyrrole, thiophene and pyridine ( π as well as n-electron donors) have been studied spectrophotometric and ultrasonic techniques at 303.15 K in dimethyl sulphoxide medium. The measured values of ultrasonic velocity, density and viscosity and the derived acoustical parameters such as adiabatic compressibility ( κ), free length ( L f), internal pressure ( π i), molar volume ( V m) and available volume ( V a) have been used to study the molecular interactions and the complexes of heterocyclic aromatic compounds. The excess thermodynamic parameters like excess velocity ( u E), excess adiabatic compressibility ( κ E), excess free length ( L f E), excess molar volume ( V m E) and excess available volume ( V a E) have been computed and the sign and magnitude of these parameters indicate the strength of interactions and the formation of charge-transfer complex. The formation constants of the charge-transfer complexes were determined by the Benesi–Hildebrand equations (optical method) and compared with those obtained from Kannappan method (ultrasonic method). The formation constants of complexes of iodine with aromatic compounds depend on the structure of the donor and acceptor molecules.

Thermoacoustical Excess Properties of Binary Liquid Mixtures - A Comparative Experimental and Theoretical Study

composition range and at T = 293, 303, 313 K. The excess pseudo-Gruneisen parameter (i E ), excess molar isentropic compressibility (K E ) and excess acoustic impedance (Z E ) were also calculated. The excess deviation functions have been correlated using Redlich{Kister polynomial equation. The observed values of the excess parameters plotted against the mole fraction of tetrahydrofuran have been explained on the basis of intermolecular interaction suggesting strong interaction in tetrahydrofuran + o-cresol than in tetrahydrofuran + methanol. Partial molar isentropic compressibility at inflnite dilution and their excess values were calculated for each component. Sanchez theory, Goldsach{Sarvas volume fraction statistics, Sudgen's relation, Flory{Patterson{Rastogi and Brock and Bird model were used with the Aurebach relation to compute theoretically the values of ultrasonic velocities at varying temperatures. The velocity deviations were estimated in terms of average percentage deviations. Internal pressure for both the systems were calculated theoretically and discussed on the basis of relative applicability of the models in theoretical estimations. The isothermal compressibility (kT), for these binary mixtures were theoretically evaluated by using the Flory statistical theory and flve hard sphere models and compared with the experimental values.

Study of acoustic parameters of binary mixtures of a nonpolar liquid with polar liquid at different frequencies

The densities (ρ) and ultrasonic velocities (C) of binary mixture of diisopropyl ether (DIPE) and bromobenzene (BB) have been measured at different frequencies (1 MHz, 3 MHz and 5 MHz) over the entire range of mole fraction of diisopropyl ether (DIPE) at temperature 303 K. The intermolecular free length (Lf), isentropic compressibility (β), acoustic impedance (Z) and excess values of isentropic compressibility (βE) and acoustic impedance (ZE) have been computed using values of ultrasonic velocity (C) and density (ρ).

Mixing properties and modelling of methanol with chlorobenzene and bromobenzene at 293, 303, and 313 K

Refractive index, ultrasonic velocity and density for the binary mixtures of methanol with chlorobenzene and bromobenzene at 293, 303, and 313 K have been measured over the entire composition range. The values of refractive index (n), ultrasonic velocity (u), and density (ρ) were used to compute deviation in molar refraction (ΔR m) and deviation in isentropic compressibility (Δκ s). The results of deviation were fitted to the Redlich–Kister polynomial equation to derive the binary coefficients and standard deviation. Both the systems exhibited negative values of ΔR m and Δκ s over the entire composition range. The density, ultrasonic velocity and refractive index were correlated to first order polynomial with respect to mole fraction. Experimental data of physical properties (refractive index, isentropic compressibility and density) were compared with the results obtained by theoretical estimation procedures.

Acoustical Studies on Molecular Interactions in Binary Liquid Mixtures at 303 K

Molecular interaction studies using ultrasonic technique in the binary liquid mixtures of cyclohexanone with o‐cresol and p‐cresol have been carried out at 303 K. Using the measured values of ultrasonic velocity, density and viscosity, acoustical parameters and their excess values are evaluated. From the properties of these excess parameters the nature and strength of the interactions in these binary systems are discussed.

Theoretical Prediction of Ultrasonic Velocity in Organic Liquid Mixtures

Theoretical values of ultrasonic velocity in the binary mixtures of cyclohexanone with 2‐propanol and 2‐methyl‐2‐propanol have been evaluated at 303 K using Nomoto’s relation, collision factor theory, free length theory, ideal mixture relation, Junjie’s method. Theoretical values are compared with the experimental values and the validity of the theories are checked by applying the chi‐square test for goodness of fit and by calculating the average percentage error (APE).

The ultrasonic and image analysis method for non-destructive quantification of the thermal shock damage in refractory specimens

In the present work, Mg-exchanged zeolit and silicon carbide were used as starting materials for obtaining cordierite/SiC composite ceramics with weight ratio 50:50. Samples were exposed to the water quench test from 950 °C, applying various number of thermal cycles (shocks). Level of surface deterioration before and during quenching was monitored by image analysis. Ultrasonic measurements were used as non-destructive quantification of thermal shock damage in refractory specimens. When refractory samples are subjected to the rapid temperature changes crack nucleation and propagation occurs resulting in loss of strength and materials degradation. The formation of cracks decreases the density and elastic properties of material. Therefore measuring these properties can directly monitor the development of thermal shock damage level. Dynamic Young modulus of elasticity and strength degradation were calculated using measured values of ultrasonic velocities obtained by ultrasonic measurements. Level of degradation of the samples was monitored using Image Pro Plus program for image analysis. The capability of non-destructive test methods such are: ultrasonic velocity technique and image analysis for simple, and reliable non-destructive methods of characterization were presented in this paper.

Interactions in l-alanine–/ l-proline–/ l-valine–/ l-leucine–aqueous KCl/KNO 3 systems at different temperatures: An isentropic compressibility study

Ultrasonic velocity and density values of amino acids: l-alanine/ l-proline/ l-valine/ l-leucine in 2.0 M aqueous KCl and 2.0 M aqueous KNO 3 solutions have been measured for several concentrations of amino acids at different temperatures: 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15 K. Using ultrasonic velocity and density data, the thermodynamic parameters such as isentropic compressibility ( κ s), change in isentropic compressibility (Δ κ s) and relative change (Δ κ s/ κ 0) in isentropic compressibility have been computed. The trends in the behaviour of κ s, Δ κ s and Δ κ s/ κ 0 with changes in the concentration of amino acids/zwitterions as well as in temperature have been discussed in terms of zwitterions–ions, zwitterions–water dipoles, ions–ions, ions–water dipoles intermolecular/interionic interactions operative in the said systems.

Effect of KCl and KNO3 on Partial Molal Volumes and Partial Molal Compressibilities of Some Amino Acids at Different Temperatures

Density (ρ) and ultrasonic velocity (u) values of amino acids l-alanine, l-proline, l-valine, and l-leucine in 2M aqueous KCl and 2M aqueous KNO3 solutions have been measured as a function of amino acid concentration at different temperatures (298.15 K, 303.15 K, 308.15 K, 313.15 K, 318.15 K, and 323.15 K). Using the ρ and u data, partial molal volume (\({\phi_{\rm v}^{\rm o}}\)) and partial molal isentropic compressibility (\({\phi_{\rm k}^{\rm o} }\)) values have been computed. The increase in partial molal volume with temperature has been attributed to the volume expansion of hydrated zwitterions. The \({\phi_{\rm v}^{\rm o}}\) and \({\phi_{\rm k}^{\rm o}}\) values of l-alanine, l-proline, l-valine, and l-leucine in 2M aqueous KCl and KNO3 solutions have been found to be larger than the corresponding values in water. The larger partial molal volumes of l-alanine, l-proline, l-valine, and l-leucine in 2M aqueous KCl and KNO3 solutions have been ascribed to the formation of ‘zwitterion-K+/Cl−/NO3−’ and ‘K+/Cl−/NO3−–water dipole’ aggregates in solutions. The formation of these entities in solutions causes the release of water associated with zwitterions to the bulk water. The larger partial molal compressibilities of l-alanine-/l-proline-/l-valine-/l-leucine–2M aqueous KCl/KNO3 solutions than the corresponding values in water have been attributed to the formation of ‘zwitterion–ion’ and ‘ion–water dipole’ incompressible entities in solutions.

Thermoacoustical response of 1,4-dioxane with carboxylic acids

Experimental values of ultrasonic velocity (u), density (ρ), refractive index (n) and viscosity (η) for the binary mixtures of 1,4-dioxane with acetic acid and propionic acid have been measured at 293, 303 and 313 K over the entire mole fraction range. Using these data, the excess adiabatic compressibility , deviation in viscosity (Δη), excess intermolecular free length , molar compressibility (B), molecular radius (r m), relaxation strength (r), and van der wall's constant (b) have been calculated. These parameters were used to study the nature and extent of intermolecular interaction between component molecules present in the binary mixtures. Excess values of βs and η were plotted against the mole fraction of 1,4-dioxane over the whole composition range. The values of , Δη and for two binary mixtures have been found to be negative which suggest the presence of weak molecular interaction in these mixtures. Molecular radius (r m) and relaxation strength (r) of liquid mixtures were also evaluated since these parameters are useful in prediction of molecular properties of liquid mixtures.

Service life prediction for refractory materials

Ultrasonic pulse velocity testing and image analysis were used to predict the thermal stability of cordierite–mullite refractories. Two compositions used as substrates in fast firing of porcelain whiteware, characterized by different microstructure and crack propagation behavior, were investigated. Fracture strength and fracture toughness values were obtained from three point bending test and chevron notched specimen technique, respectively. The measurement of the ultrasonic velocity was used to assess the material degradation with increasing number of thermal-shock cycles and specimen damage was monitored using image analysis to obtain further evidence of material degradation. The correlation between thermo-mechanical properties, ultrasonic velocity, microstructure, crack-propagation behavior and thermal-shock resistance was discussed. A remarkable similarity was found between the variation of ultrasonic velocity (when measured through the length of the refractory plates) and fracture strength with number of thermal shock cycles. On the other hand, the development of surface microcracking, as monitored by image analysis, is in good agreement with the variation of KIC with the number of thermal-shock cycles. The variation of the \(\frac{d\sigma_{\rm f}}{dE_{\rm dyn}}\) ratio with number of thermal-shock cycles shows the highest gradient of the investigated trends and it is proposed as a promising parameter to differentiate refractory materials regarding their different thermal shock behavior. Service life prediction models for refractory plates, from measured values of ultrasonic velocity and surface damage analysis, were proposed and validated.