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

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

Influence of methane and carbon monoxide in the volumetric behaviour of the anthropogenic CO2: Experimental data and modelling in the critical region

Density measurements of the systems CO 2 + CH 4 at T = 304.21 K and CO 2 + CO at T = 304.21 and 308.15 K were carried out at pressures and compositions of interest in the process of transport and storage of CO 2 (CCS technology): P = 0.1 to 20 MPa, and xCO 2 ≥0.97. From the experimental P––T –xCO 2 data, we have studied the dependence of the isothermal compressibility, the excess molar volume, and the par- tial molar volume of the solute with composition, pressure and temperature within the critical region. We have modelled the volumetric behaviour of these systems with Peng–Robinson, PC-SAFT and GERG Equations of State, thus validating these equations under the conditions considered. Furthermore, we have confirmed the weakly attractive behaviour of these systems by performing a study of the interac- tions between solvent molecules, CO 2 , and those of the solute, CO or CH 4 , using the Krichevskii Function concept and the Kirkwood–Buff Theory. Finally, we have quantified the influence of small amounts of CH 4 and CO in the transport of anthropogenic CO 2 through several normalized parameters, related to the design and operation of the fluid transport process

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

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

High-pressure speed of sound in pure CO2 and in CO2 with SO2 as an impurity using methanol as a doping agent

Reliable speed of sound, c, values in CO2- rich mixtures and pure CO2 are required for carbon capture and storage (CCS) technology but are difficult to determine, particularly at relatively high frequencies. We tested the suitability of methanol as doping agent to obtain accurate c values in CCS systems at 5 MHz. We measured c in seven CO2-rich, CO2 + methanol mixtures between 263.15 and 323.15 K and up to 196.30 MPa, and we extrapolated the values to obtain c in pure CO2. Additionally, we measured c from 263.15 to 373.19 K and up to 190.10 MPa in two CO2-rich, CO2 + SO2 mixtures with the same SO2 composition, which is of interest for CCS, with one mixture doped with methanol. We compared our results for pure CO2 with the literature and the Span and Wagner equation of state (EoS). We validated the PC-SAFT EoS and the modeling with the REFPROP 9 software for the mixtures by comparing the predicted values with our experimental data under the studied conditions. We conclude that methanol is a suitable doping agent to measure c in pure CO2 and CO2-rich mixtures. For the CO2 + SO2 mixtures, the effect of methanol on the experimental values is small and negligible for modeling

Planck-LFI radiometers' spectral response

The Low Frequency Instrument (LFI) is an array of pseudo-correlation radiometers on board the Planck satellite, the ESA mission dedicated to precision measurements of the Cosmic Microwave Background. The LFI covers three bands centred at 30, 44 and 70 GHz, with a goal bandwidth of 20% of the central frequency. The characterization of the broadband frequency response of each radiometer is necessary to understand and correct for systematic effects, particularly those related to foreground residuals and polarization measurements. In this paper we present the measured band shape of all the LFI channels and discuss the methods adopted for their estimation. The spectral characterization of each radiometer was obtained by combining the measured spectral response of individual units through a dedicated RF model of the LFI receiver scheme. As a consistency check, we also attempted end-to-end spectral measurements of the integrated radiometer chain in a cryogenic chamber. However, due to systematic effects in the measurement setup, only qualitative results were obtained from these tests. The measured LFI bandpasses exhibit a moderate level of ripple, compatible with the instrument scientific requirements.Comment: 16 pages, 9 figures, this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins

Vision-Depth Landmarks and Inertial Fusion for Navigation in Degraded Visual Environments

This paper proposes a method for tight fusion of visual, depth and inertial data in order to extend robotic capabilities for navigation in GPS-denied, poorly illuminated, and texture-less environments. Visual and depth information are fused at the feature detection and descriptor extraction levels to augment one sensing modality with the other. These multimodal features are then further integrated with inertial sensor cues using an extended Kalman filter to estimate the robot pose, sensor bias terms, and landmark positions simultaneously as part of the filter state. As demonstrated through a set of hand-held and Micro Aerial Vehicle experiments, the proposed algorithm is shown to perform reliably in challenging visually-degraded environments using RGB-D information from a lightweight and low-cost sensor and data from an IMU.Comment: 11 pages, 6 figures, Published in International Symposium on Visual Computing (ISVC) 201