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1.
Acoustic non-linearity parameter B/A is calculated for five binary liquid mixtures using Tong and Dong equation along with
the Flory’s statistical theory. Similar to other excess thermodynamical quantities an excess non-linearity parameter (B/A)E is defined for binary liquid mixtures. The interactions in the liquid mixtures are explained on the basis of the excess non-linearity
parameter. 相似文献
2.
The present investigation comprises of theoretical evaluation of acoustic non-linearity parameter,B/A for equimolar binary mixtures, viz. chlorobenzene or 1-chloronaphthalene with a series of normal alkanes (n-Cn,n = 6, 8, 10, 12, 14, 16), and with a series of highly branched alkanes (br-Cn,n = 6, 8, 12, 16), viz. 2,2-dimethylbutane (br-C6), 2,2,4-trimethylpentane (br-C8), 2,2,4,6,6-pentamethylheptane (br-C12) and 2,2,4,4,6,8,8-heptamethylnonane (br-C16). Tong and Dong method, thermoacoustical method, Hartmann relation and Ballou relation have been employed to evaluateB/A. A comparative study ofB/A values obtained from the aforementioned methods has been made. The results are discussed on the basis of structural orientations
of normal and branched alkanes. 相似文献
3.
When sound waves of high amplitude propagate, several non-linear effects occur. Ultrasonic studies in liquid mixtures provide
valuable information about structure and interaction in such systems. The present investigation comprises of theoretical evaluation
of the acoustic non-linearity parameter B/A of four binary liquid mixtures using Tong and Dong equation at high pressures and T=303.15 K. Thermodynamic method has also been used to calculate the non-linearity parameter after making certain approximations. 相似文献
4.
Acoustic non-linearity parameter B/A is calculated for binary mixtures using four different methods. The interactions in the liquid mixtures are explained on the basis of excess non-linearity parameter and excess adiabatic compressibility. Sehgal's relations for calculating molecular properties of pure liquids are extended to binary mixtures. 相似文献
5.
I.Introductionlnthcearlyfifties,thercweremanyresearchworksonpropagatingmechanismofultrasonicwaveinseawater,itssoundve1ocity,absorptionandattenuation.Withthedevelop-mcntandapp1icationofhigh-powersoundsourcc,suchasSONARinnavy,thenonlinearacousticaleffectscausedbyfiniteamplitudeu1trasonicwavetravellingthroughseawaterbecomemoreevident.Thcrcfore,tostudythesenonlinearacousticaleffectsandtheirinfluenccsalsobecomcsmuchmoreimportant.Moreover,ithasbeenexpccted'foralongtimetogetalowfrequencyandhighlydi… 相似文献
6.
Influences of structural factors of biological media on the acoustic nonlinearity parameter B/A 总被引:3,自引:0,他引:3
The influence of structural factors of biological media on the acoustic nonlinearity parameter B/A have been studied at the tissue, cellular, and molecular levels, using the thermodynamic and finite amplitude methods. B/A was determined as the structural factors of the media were altered physically and biochemically, while chemical composition was maintained unchanged. Significant structural dependencies of B/A were observed at all three levels; 26% of the dry weight contribution to the total B/A (the B/A value with water contribution subtracted) is due to the cell-cell adhesive force in liver tissue, 20% is due to the hepatocyte cellular structure, and 15% is due to secondary and tertiary protein structure. 相似文献
7.
Exploring new acoustic parameters is essential to develop a noninvasive imaging technique for the surgery of silicone oil tamponades. In this study, the acoustic nonlinearity parameters B/A of varied silicone oil samples(e.g., linear or hyperbranched) are experimentally measured by using a modified thermodynamic method. The results show that:(i) when the concentration of the silicone oil with a molecular weight of 5 × 104increases from 0.5 g/100 ml to 8 g/100 ml, the corresponding B/A value increases by about 18%, but the acoustic velocity only increases by about 0.1%;(ii) when the molecular weight of the hyper-branched silicone oil is enhanced from 2 × 105to 1 × 106, the B/A value increases by about22%, while the acoustic velocity is only raised by about 0.2%. This study suggests that the B/A parameter of the silicone oil is more sensitive to the change in its molecular structure than that of the acoustic velocity. Thus, the B/A parameter might be utilized as an effective index for the development and optimization of the noninvasive imaging of the surgery of silicone oil tamponades. 相似文献
8.
D. Madhavi LathaV.G.K.M. Pisipati C. Rama Chandra PrabhuP.V. Datta Prasad 《Journal of Molecular Liquids》2011,164(3):187-190
The thermodynamic parameters like Moelwyn-Hughes parameter (C1), reduced molar volume (V~), isochoric temperature coefficient of internal pressure (X), Huggin's parameter (F), Gruneisen parameter (Γp), isothermal microscopic Gruneisen parameter, Sharma parameter (So), fraction free volume (f) and (A?) a dimensionless thermal parameter, etc and the Beyer's nonlinearity parameter (B/A) were deduced employing the thermal expansion coefficient derived from density data for the homologues series of compounds terephthalyidene-bis-p-n-alkyl anilines, TBnA with n = 5 to 10,12,14,16 and 18. Further, it is found that the variation of molecular radius, Mr increases with the increase of alkyl chain number, with a core radius of 4.78 Å and the increment for methylene unit is 0.086 Å . The results were discussed with the body of the data available. 相似文献
9.
Densities and ultrasound velocities for the binary mixtures of 1-bromobutane+benzene and 1,4-dimethylbenzene and of 1-bromopentane+cyclohexane and benzene have been measured at 308.15 K. Adiabatic compressibilities (beta(ad)), and Wada's constants (W) have also been evaluated as a function of composition. The ultrasound velocities decrease, attains a minimum and then increase with increase in mole fractions of hydrocarbons in the binary mixtures except in the case of 1-bromopentane+benzene binary mixtures where the variation is just the reverse. Dependence of adiabatic compressibilities with mole fractions of hydrocarbons is sigmoid. The non-ideal behaviour of the systems studied is explained on the basis of dipole-induced dipole interactions. 相似文献
10.
I.IntroductionAcousticnonlinearityparameterB/Adescrjbesthenonlilleareffectsofasoundwavetrav-ellingthroughamedium.Withtheapplicationofhighmowerultrasonicwavetomedicine,thenonlineareffectsbecomemoreandmoreimportant.EspeciallybecauseB/Aissensitivetothepathologicalstateofbiologicaltissues[1-2])thisprovidesprospectiveapplicationinmedicaldiagnosis.Atpresent,thestudyinthisareaemphasizesontwoaspects.OneistodevelopnewmedicalimagingtechniquesbyusingthisnonlinearityparameterB/Al1'3-'];theotheristostu… 相似文献
11.
Ultrasonic study on organic liquid and binary organic liquid mixtures by using Schaaffs' collision factor theory 总被引:1,自引:0,他引:1 下载免费PDF全文
Based on Schaaff's collision factor theory (CFT) in liquids, the equations for
nonlinear ultrasonic parameters in both organic liquid and binary organic liquid
mixtures are deduced. The nonlinear ultrasonic parameters, including pressure
coefficient, temperature coefficients of ultrasonic velocity, and nonlinear acoustic
parameter B/A in both organic liquid and binary organic liquid mixtures, are
evaluated for comparison with the measured results and data from other sources. The
equations show that the coefficient of ultrasonic velocity and nonlinear acoustic
parameter B/A are closely related to molecular interactions. These nonlinear
ultrasonic parameters reflect some information of internal structure and outside
status of the medium or mixtures. From the exponent of repulsive forces of the
molecules, several thermodynamic parameters, pressure and temperature of the medium,
the nonlinear ultrasonic parameters and ultrasonic nature of the medium can be
evaluated. When evaluating and studying nonlinear acoustic parameter B/A of binary
organic liquid mixtures, there is no need to know the nonlinear acoustic parameter
B/A of the components. Obviously, the equation reveals the connection between the
nonlinear ultrasonic nature and internal structure and outside status of the
mixtures more directly and distinctly than traditional mixture law for B/A, e.g.
Apfel's and Sehgal's laws for liquid binary mixtures. 相似文献
12.
13.
Densities ρ and ultrasonic speeds u of the binary mixtures of tetrahydrofuran (THF) with 1-butanol and tert-butanol, at 30°C, over the entire composition range
were measured. From these data isentropic compressibility, K
s, intermolecular free length L
f, relative association R
A, acoustic impedance Z, molar sound speed R
m, deviations in isentropic compressibility ΔK
s, and excess volume V
E were calculated. The variation of these parameters with composition of the mixture helps us in understanding the nature and
extent of interaction between unlike molecules in the mixtures. Further, theoretical values of ultrasonic speed were evaluated
using theories and empirical relations. The relative merits of these theories and relations were discussed. 相似文献
14.
15.
Measured data for the temperature of a porous spherical surface to which an evaporating binary liquid mixture was supplied
are reported. In the experiments, solutions of ethyl and methyl alcohols in water, and also solutions of acetone in water,
were used. The concentration of mixture components was varied throughout the widest possible range of X
L
= 0–1, and the temperature of dry air flow past the sphere was in the range t
0 = 15–300 °C. In the present study, a strong influence of the composition of the mixtures on their adiabatic evaporation temperature
was established. In the heat- and mass-transfer process, the air temperature is also of paramount importance. An experimental
correlation is obtained which generalizes data on adiabatic evaporation temperature in a broad range of component concentrations
and temperatures for the experimentally examined binary liquid mixtures.
This work was supported by the Russian Foundation for Basic Research (Grant No. 06-08-39002—GFEN). 相似文献
16.
17.
The excess parameter studies in the microwave frequency region (X-band) on complex dielectric permittivity for the binary
mixtures are reported. The methods employed are fixed cavity perturbation technique and adjustable plunger cavity technique.
Also Gopalakrishna method is used to calculate the relaxation time of the polar solute in a non-polar solvent. The samples
under study are acetonitrile, chlorobenzene, dimethyl formamide, carbon tetrachloride and benzene. 相似文献
18.
A. Anis Fathima M. Umadevi M. S. Ramachandran V. Ramakrishnan 《Journal of Raman spectroscopy : JRS》2007,38(12):1639-1645
A vibrational spectroscopic study of binary mixtures of salicylaldehyde (SA) in three different solvents (polar and nonpolar) is presented. The vibrational modes ν(CO), hydroxyl stretching mode (C OH) and aldehydic (C H) stretching vibration were analyzed. Changes in wavenumber position and full width half maximum have been explained for neat as well as binary mixtures with different volume fractions of the reference system, SA, in terms of inter‐ and intramolecular hydrogen bonding. The IR spectra of these mixtures have also been taken and compared with the Raman data. The spectral changes have been well explained using the concentration fluctuation model and solute–solvent interaction. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
19.
20.
An analytical expression for the pressure-temperature-composition relations in the vapour - liquid equilibrium of non-polar binary mixtures is proposed. The model is based on a simple analytical expression for the vapour pressure of pure non-polar fluids, which, for a given temperature, requires as input only the Lennard- Jones molecular parameters and the acentric factor of the substance. The equilibrium mixture pressure is then expressed as a function of the vapour pressure of each component and of a mixture contribution. The molecular parameters required for this mixture contribution are related to the molecular parameters of the pure component through a modified Lorentz-Berthelot mixing rule, where the interaction parameters are given as simple functions of the temperature and composition, with eight appropriate constants for each binary mixture. We show that the model permits one to reproduce or predict in a simple way the pressure (for a given liquid mole fraction) or the liquid composition (for a given pressure). 相似文献