Hydro-Québec

About: Hydro-Québec is a government organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Electric power system & Dielectric. The organization has 2596 authors who have published 4433 publications receiving 100878 citations.

A comprehensive thermodynamic investigation of water-ethylene glycol mixtures at 5, 25 and 45°C

Abstract: A detailed thermodynamic study of water (W)-ethylene glycol (EG) mixtures has been carried out as function of temperature (5, 25 and 45°C) and over the entire composition range. The data comprise heats of mixing, densities, heat capacities and compression coefficients. Using excess free energy data from earlier work, molar excess functions were calculated for free energies GE, enthalpies HE and entropies TSE, volumes VE, isobaric and isochoric heat capacities C P E , C V E , adiabatic and isothermal compression KE, K T E and thermal expansion EE, as well as the temperature derivatives of K, C and E functions. The corresponding partial molar quantities were also calculated except for G, H and S and are reported for both EG and W. Also calculated were cohesive energy density, internal pressure and Kirkwood-Buff integrals. The data reported here for EG-W mixtures are compared with similar data for other mixtures as available in order to gain insight into: 1) the relative discriminating ability of various thermodynamic coefficients towards weak cooperative intermolecular interactions in liquids; 2) the quantitative similarities and differences between liquid water and ethylene glycol; 3) the intermolecular phenomena which dominate the properties of EG-W mixtures of varying composition; 4) the usefulness of a qualtitative description of liquid water proposed by Lumry et al. which involves hydrogen-bonding interactions, hydrogen-bonding connectivity and small cooperative fluctuation units.

Optical Properties of Some Pb 1 − x Sn x Te Alloys Determined from Infrared Plasma Reflectivity Measurements

Abstract: The infrared reflectivity was measured as a function of hole concentration at 82 \ifmmode^\circ\else\textdegree\fi{}K for ${\mathrm{Pb}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}\mathrm{Te}$ alloy samples with $x=006 \mathrm{and} 021$ and as a function of temperature for one sample with $x=021$ and hole concentration 87\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ The measured reflectivity spectra were remarkably well fitted by the classical free-carrier dispersion relations The optical dielectric constant ${\ensuremath{\epsilon}}_{\ensuremath{\infty}}$, the susceptibility effective mass ${m}_{s}$, and the optical mobility ${\ensuremath{\mu}}_{\mathrm{opt}}$ were determined from a curve-fitting technique and a minimum-reflectivity technique generalized to include the effect of nondegeneracy Using the former technique, a second valence-band maximum situated at about 023 eV below the main valence-band maximum was detected in the alloy with $x=021$ The energy gap and ${\ensuremath{\epsilon}}_{\ensuremath{\infty}}$ were found to be related by $\mathrm{ln}{E}_{G}=0086{\ensuremath{\epsilon}}_{\ensuremath{\infty}}+165$ in lead-rich ${\mathrm{Pb}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}\mathrm{Te}$ alloys The optical mobility was found to be about a factor of 2 lower than the conductivity mobility in all samples measured The experimental values of ${m}_{s}$ were compared with those expected from the Kane, Cohen, and Dimmock models The results of these comparisons indicate that the two-band models of Kane and Cohen, especially the former, are more suitable than the six-band model of Dimmock to explain the carrier-concentration dependence of ${m}_{s}$, and that none of the models account for the large increase of ${m}_{s}$ with temperature

Open data IEEE test systems implemented in SimPowerSystems for education and research in power grid dynamics and control

Abstract: This paper presents three IEEE standardized power system benchmarks developed in SimPowerSystems, a MATLAB/Simulink package. The simulation models can be used for baselining and testing new control techniques and protection algorithms for renewable and micro grids integration studies. Analytical examples as well as static, time domain, and frequency analysis are presented to support the correctness of the implementation. The models are available in MATLAB-Central file exchange for power system education and research worldwide.