<p>The ultrasonic velocity, density and viscosity at 318K have been measured in the binary systems of Methyl methacrylate + Toluene and Methyl methacrylate + Dimethylacetamide. In this work an attempt has been made for the first time to investigate the behavior of binary solutions of Methylmethacrylate(MMA) in Toluene and Dimethylacetamide(DMAC) with regard to acoustical parameters such as adiabatic compressibility(β), intermolecular free length(l<sub>f</sub>), free volume(V<sub>f</sub>), Rao’s constant(R), Wada’s constant(W) and specific acoustical impedance(Z) from ultrasonic measurements at 318 K were calculated. The results are interpreted in terms of molecular interaction between the components of mixtures.</p>
Molecular interaction studies using ultrasonic technique in the binary liquid mixtures of cyclohexanone witho-cresol andp-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.
The ultrasonic velocity, density and viscosity at 303 K have been measured in the binary systems of 1,4-dioxane and acetone with water. From the experimental data, various acoustical parameters such as adiabatic compressibility (β), intermolecular free length (Lf), free volume (Vf), internal pressure (πi), Rao’s constant (R), Wada’s constant (W) and specific acoustical impedance (Z) were calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.
Humans excel at assessing conspecific emotional valence and intensity, based solely on non-verbal vocal bursts that are also common in other mammals. It is not known, however, whether human listeners rely on similar acoustic cues to assess emotional content in conspecific and heterospecific vocalizations, and which acoustical parameters affect their performance. Here, for the first time, we directly compared the emotional valence and intensity perception of dog and human non-verbal vocalizations. We revealed similar relationships between acoustic features and emotional valence and intensity ratings of human and dog vocalizations: those with shorter call lengths were rated as more positive, whereas those with a higher pitch were rated as more intense. Our findings demonstrate that humans rate conspecific emotional vocalizations along basic acoustic rules, and that they apply similar rules when processing dog vocal expressions. This suggests that humans may utilize similar mental mechanisms for recognizing human and heterospecific vocal emotions.
Knowledge of acoustical properties of granular and fibrous sustainable materials has been stimulated thanks to their rather easy handling and durability. In this work direct measurements of the normal incidence sound absorption coefficient of three non consolidated materials (esparto fibers, cork and perlite) have been carried out using the so-called transfer function method. These materials are plentiful in Morocco and they require low amounts of energy for processing, which makes them attractive as either thermal insulating or sound absorbing materials. Results show that the acoustical efficiency of studied materials is comparable to traditional materials. In addition, an inverse estimation of non acoustical parameters (flow resistivity, tortuosity and porosity) of these materials has been performed introducing a new predictability approach. This is based on Global Sensitivity Analysis combined with Global Numerical Optimization Techniques, regarding most usual mathematical models.
Ultrasonic study of molecular interactions in binary mixtures of methyl methacrylate(MMA) with toluene and dimethylacetamide at 318 K
