Volumetric Behavior and Vapor–Liquid Equilibrium of Dimethyl Disulfide + n-Alkanol Binary Mixtures

In this paper, we report densities at 303.15 and 323.15 K and at atmospheric pressure (p = 0.1 MPa) of the binary mixtures containing dimethyl disulfide and a linear alkanol (methanol, ethanol, 1-propanol or 1-butanol). The isothermal vapor–liquid equilibrium for these systems was also determined at the same temperatures while the pressure range for vapor–liquid equilibrium measurement depends on both the mixture and temperature considered. The vapor–liquid equilibrium data were found to be thermodynamically consistent. From these data experimental excess volumes and excess Gibbs functions were obtained and correlated with composition using the Redlich–Kister polynomial expansion and the Wilson equation, respectively. The values of both excess properties were positive. The excess volumes, unlike the excess Gibbs functions, increase with the length of the n-alkanol chain

Thermophysical study of the binary mixtures of N, N-dimethylacetamide with 1-propanol and 1-butanol

Several thermophysical properties such as densities, p, speeds of sound, u, refractive indices, nD, and kinematic viscosities, v, have been measured for the binary mixtures of N, N-Dimethylacetamide with 1-propanol and 1-butanol over the entire range of composition, at the temperatures (283.15, 298.15 and 313.15) K and at atmospheric pressure p = 0.1 MPa. From these experimental data, excess molar volumes, VE, excess isentropic compressibilities, ?S E , refractive index deviations, ?nD, and viscosity deviations, ??, were calculated. Then, correlated with the Redlich-Kister equation and the corresponding parameters were drived. The results obtained, were discussed in terms of structural effects and specific molecular interactions, and the influence of the alkanol chain length was also considered

Biomechanics of fish swimming in a hydrokinetic turbine wake

In the present paper, the assessment of the hydrodynamics of the fish swimming in undisturbed and altered wake-flow is carried out identifying hydrodynamical forces and flow patterns of the fish swimming wake. URANS approach with k-omega/SST turbulence model are employed combining fish and turbine in the same simulation. Fish motion is realized using dynamically adaptive mesh. The actuator line method is employed to induce the wake of a hydrokinetic turbine, which is a simplified method that requires lower computational cost than full geometry simulations. This work brings a new numerical approach involving fish and turbine wake highlighting that fish swimming in the wake presents higher thrust forces than in the undisturbed flow, due to the x-component to velocity in the wake is lower than free flow velocity

Volumetric and acoustic behaviour of myo-inositol in aqueous Natural Deep Eutectic Solvent solutions

A study of the interactions in aqueous systems containing a sweetener, myo-inositol, and a NAtural Deep Eutectic Solvent, reline or glyceline, is presented. Both NADESs include the same acceptor group, choline chloride, and different donor groups, urea and glycerol. For this purpose, the density and speed of sound were measured for dilute mixtures, and several related properties were calculated: the standard partial molar volume, the standard partial molar isentropic compression, the standard transfer properties, Hepler's constant, and the compressibility hydration number. The results were evaluated as a function of the temperature and composition, and they show the dominance of the ionic-hydrophilic and hydrophilic-hydrophilic interactions. Moreover, the glyceline disturbs the aqueous mixtures more than the reline

The NADES glyceline as a potential Green Solvent: A comprehensive study of its thermophysical properties and effect of water inclusion

In this paper, two Natural Deep Eutectic Solvents, glyceline (Gly) and glyceline-water (GlyW), containing choline chloride as acceptor H-bond compound and glycerol as donor H-bond group are studied. For glyceline the mole relation is 1 (choline chloride): 2 (glycerol) and for glyceline-water the mole relation is 1 (choline chloride): 1.99 (glycerol): 1.02 water. The ternary NADES has been synthetized and characterized chemically by NMR techniques for this work. Several thermophysical properties in a wide range of temperature (278.15–338.15)¿K and at atmospheric pressure (0.1¿MPa) have been measured for both compounds: density, , speed of sound, , refractive index, , surface tension,, isobaric molar heat capacity, , kinematic viscosity, , and electric conductivity,. Furthermore, some related properties have been also calculated: isobaric expansibility, , isentropic compressibility, , molar refraction, , entropy and enthalpy of surface formationper unit surface area ( and ), and dynamic viscosity, , and viscous flow and electrical conductivity activation energies. The results have been discussed in terms of the effect of temperature and the inclusion of water. We conclude that the compound containing water into the structure has a higher molar volume and a higher fluidity. The binary NADES (Gly) is a more structured liquid than ternary one (GlyW)

Thermophysical characterization of the deep eutectic solvent choline chloride:ethylene glycol and one of its mixtures with water

The deep eutectic solvent ethaline, containing choline chloride as H-bond acceptor and ethylene glycol as H-bond donor and one of its mixture with water are studied in this work. Ethaline is anhydrous, with a 1:2 mol ratio. Hydrated ethaline, choline chloride:ethylene glycol:water, was studied in a 1:1.98:0.95 mol ratio. Several volumetric, acoustic, optical, thermal, surface, and transport properties were measured and calculated. The working temperature ranges from 278.15 to 338.15 K at pressure = 0.1 MPa. The effects of temperature, water inclusion, and the nature of the donor compound are evaluated. With regard to temperature, the system''s behaviour is as expected: a linear relation for the thermodynamic properties and agreement with the Vogel-Fulcher-Tammann equation for the transport properties. The water molecules hardly modify the ethaline structure. The choline chloride – ethylene glycol interactions are weaker than those for choline chloride - glycerol

Thermophysical study of 2-acetylthiophene: experimental and modelled results

Several thermophysical properties have been studied for 2-acetylthiophene: (i) vapour pressure was determined at temperatures within 336.16–445.02 K; (ii) density, speed of sound, static permittivity, refractive index, surface tension, and kinematic viscosity were measured at p = 0.1 MPa and at temperatures from 278.15 K (or 283.15 K for the refractive index) to 338.15 K; (iii) volumetric properties were also determined at temperatures in the (283.15–338.15) K range and at pressures up to 65.0 MPa. From these experimental values, different derivative properties have been calculated such as enthalpy of vaporization, isobaric expansibility, isothermal and isentropic compressibility, dipole moment, entropy and enthalpy of surface formation, and dynamic viscosity. All experimental properties were correlated and the results were explained through the intermolecular interactions. Moreover PC-SAFT EoS was used to model the thermodynamic behaviour of the compound. Finally, this EoS combined with the Density Gradient Theory allowed obtaining the influence parameter for the surface tension of 2-acetylthiophene

Using Taxes to Manage a Multigear Fishery: An Application to a Spanish Fishery

When fishing gears alter the composition of fish populations or modify the recruitment rate, it is advisable to include the degree of their fishing selectivity in the analysis. Fishing selectivity can cause two different management problems: interspecies selectivity or by‐catch of fish stocks for which no quota has been set by the regulator. The case study is the Spanish fishery of hake (Merlucius merlucius), where the fleet operates using two main gears; most of the vessels are trawlers but a few boats use longlines and other fixed gears. Fishery management by means of effort taxes and how the degree of intraspecies selectivity may affect the resource and tax levels are analyzed. The results show that the tax level will depend on the social value of the marine stock, the marginal productivity of each fleet\u27s effort, and the effect that the fishing activity of each one has on the growth of the hake biomass

Direct costs of glaucoma: Relationship between cost and severity of the disease

o estimate the direct medical costs associated with the management of patients with primary open-angle glaucoma and to compare the costs of patients according to the degree of severity. A longitudinal retrospective study was carried out using all patients with primary open-angle glaucoma that recorded follow-up from May 2010 to June 2013 at the Hospital Privado de Córdoba. We estimated the cost of the disease from the perspectives of the institution, with a bottom-up approach. Results: The three-year follow-up after treatment of 104 patients revealed that the average cost of care for a patient with primary open-angle glaucoma was US$2746 ± 1560. The first year of treatment was significantly more expensive than subsequent ones (US$1100–$810–$827). Cost was related to the degree of severity of glaucoma; patients in “Stage 0” had significantly lower costs than those in other groups (Kruskal–Wallis test, p < 0.01). This was a consequence of lower costs associated with medication and a lower percentage of patients undergoing surgery. The direct medical costs of a patient with primary open-angle glaucoma vary according to the severity of their disease and the year of treatment. We found that costs increased with disease severity, but decreased over time.Fil: Real, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Lafuente, M. C.. Hospital Privado Centro Medico de Córdoba; ArgentinaFil: Palma, Santiago Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Tartara, Luis Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; Argentin

pVT behaviour of hydrophilic and hydrophobic eutectic solvents

Among the basic principles of green chemistry is the search for less harmful alternative solvents than conventional solvents. Knowing the thermophysical properties of fluids under different pressure and temperature conditions is essential to propose them. Herein, we present data on the densities at several pressures (from 0.1 to 65 MPa) and temperatures (from 283.15 to 338.15 K) of two deep eutectic solvents with hydrophilic characteristics (choline chloride + ethylene glycol or glycerol) and two eutectic solvents with hydrophobic characteristics (camphor + thymol or menthol). We used the Tait equation of state to correlate and calculate derived properties. Moreover, we modelled the mixtures with the PC-SAFT equation of state. The results showed that the hydrophilic solvents were more compact than the hydrophobic ones. The former exhibited an abnormal thermal behaviour of the isobaric thermal expansibility. The deviations in the correlation of densities with the thermodynamic model were between 0.5 and 3%. They were lower for the mixtures with weaker interactions