Analysis of correlation between viscosity Arrhenius parameters: Extension to ternary liquid mixtures

The study of viscosity-temperature dependence is important for the design and the optimization of several industrial processes and products. In this context, an interesting equation is recently proposed for pure solvents correlating the two parameters of the viscosity Arrhenius-type equation, as knowing the activation energy (Ea) and the pre-exponential factor (As), allowing the simplification of the viscosity Arrhenius equation to become an expression depending on only one parameter instead of two. The present work investigates the validity of the simplified Arrhenius-type equation for ternary fluids mixtures. The extension of the proposed equation to ternary liquid mixtures is very important since it simplifies the estimation of viscous behavior and the ensuing calculations. Using statistical methods and 114 experimental data from the literature on viscosity for 5 ternary liquid mixtures over different temperature ranges at atmospheric pressure, we found that the validation of the proposed equation depends significantly on the density of liquids and is validated only for 4 studied ternary liquid mixtures. This result opens the way to investigate the sensitivity of the equation’s parameters for more specific mixtures.

Saussure's équivalence sémiologique in the case study of Czech sonants

In “Réflections inédites de Saussure sur les phonèmes” (1973: 287–295), Roman Jakobson mentions an untitled manuscript, described as “étude phonetique.” In it, Saussure provides an interesting equation: phonème = valeur sémiologique. The equation stresses the purely semiological aspect of the phoneme and will serve as a focal point for the analysis carried out in this paper. The discussion will also explore two other related concepts introduced in the manuscript and in the only book Saussure ever published,This study attempts to draw implications for a semiotic theory of phonology based on acoustic cues found in a case study of consonant / liquid / consonant (CLC/#) clusters that occur as congeners in two cognate Slavic languages: Polish and Czech. Apart from the semiological insights of Saussure, the study's analytical perspective also builds on the semiotic oeuvre of Roman Jakobson and Boris Uspiensky (Tartu semiotics). The Tartu notion of cultural text is a sort of time center, or a groove for the discussion. The empirical section analyzes a corpus of recordings of CLC clusters in various languages collected by the author, treating particular spectrograms as cultural texts in the Tartu understanding of the term: as visual data generated by a particular speech community.

Wilsak-Thodos Equation of State for Refrigerants

In recent years different equations of state for environmentally friendly refrigerants have been developed from different sources of experimental data which, in many cases, use a very large number of auxiliary functions and coefficients. A rather interesting equation that has not been recollected lately, proposed by Wilsak and Thodos in 1985, appears to have a convenient form for effective and significantly accurate calculations of the thermophysical properties of substances. Wilsak-Thodos equation of state presents a relatively simple form as it correlates experimental data with the corresponding ones at saturation and contains only three density dependent functions. For this reason, this study attempts to identify the coefficients of the equation approximating accurately the experimental data and attributing in an integrated manner with auxiliary equations for some of the most common of the environmental friendly refrigerants.