Physical properties of fatty acid methyl esters. IV. Ultrasonic sound velocity

Abstract

The ultrasonic sound velocity of the unsaturated fatty acid methyl esters from acetate to nonadecanoate, methyl oleate, linoleate, linolenate, and erucate have been measured at 20C and 40C in the liquid state. Data of the saturated compounds were correlated with the Smittenberg relation and a reasonable fit was noted. The molar sound velocity according to Rao was computed from the observed values and increments for the CH2 group and for the double bond are presented.

Measurement and prediction of speeds of sound of fatty acid ethyl esters and ethylic biodiesels

“…High speeds of sound increase the combustion temperature and consequently the amount of NOx emissions [19]. This property also permits the estimation of other thermodynamic properties like isentropic and isothermal compressibilities, isobaric thermal expansion coefficient, thermal pressure coefficient and the reduced bulk modulus [20,21].…”

“…Unfortunately there are but a few data available in the literature for fatty acid methyl esters (FAMEs) [13,21,12,[23][24][25][26][27] being the experimental speeds of sound of fatty acid ethyl esters (FAEEs) even more scant [28], although some studies were already done for the shorter methyl and ethyl esters [29]. There at, this work aims at providing new experimental data of speed of sound for nine saturated and unsaturated FAEE and four ethylic biodiesels, measured at atmospheric pressure and temperatures from 293.15 to 343.15 K, and then using them to evaluate the predictive ability of Wada's group contribution method [28].…”

Solid fat content determination by ultrasonic velocimetry

“…The ultrasonic velocity of liquid oils has been correlated to the average molecular structure of the fatty acids present (e.g., chain length and degree of unsaturation), hence, ultrasonic velocimetry has been proposed as a means of assessing the origin or quality of edible oils (Gouw & Vlugter, 1964, 1966, 1967Javanaud & Rahalkha, 1988;McClements & Povey, 1988a;Rao, Reddy, & Prabhu, 1980;Singh & Singh, 1980). The ultrasonic absorption spectra of liquid oils depend on their high frequency shear and compression rheology (Gladwell, Javanaud, Peters, & Rahalkar, 1986;Grigor'ev, Manucharov, Mikhailov, & Khakimov, 1976).…”

Thickness dependence of magnetic and transport properties in organic-CoFe discontinuous multilayers

“…The energies of phonon fitted from the three samples are, respectively, 2.2, 2.7, and 3.05 meV. The relatively small energy of phonon corresponds to the slow sound velocity in saturated fatty acids 17 as compared with a typical insulating solid state material. The energy of phonon increases with the thickness of CoFe.…”