Giant Barocaloric Effect at the Spin Crossover Transition of a Molecular Crystal

The first experimental evidence for a giant, conventional barocaloric effect (BCE) associated with a pressure‐driven spin crossover transition near room temperature is provided. Magnetometry, neutron scattering, and calorimetry are used to explore the pressure dependence of the SCO phase transition in polycrystalline samples of protonated and partially deuterated [FeL2][BF4]2 [L = 2,6‐di(pyrazol‐1‐yl)pyridine] at applied pressures of up to 120 MPa (1200 bar). The data indicate that, for a pressure change of only 0–300 bar (0–30 MPa), an adiabatic temperature change of 3 K is observed at 262 K or 257 K in the protonated and deuterated materials, respectively. This BCE is equivalent to the magnetocaloric effect (MCE) observed in gadolinium in a magnetic field change of 0–1 Tesla. The work confirms recent predictions that giant, conventional BCEs will be found in a wide range of SCO compounds

Securitization and financialization

Securitization and financialization are the main causes of the financial crisis. These two concepts explain not only Minsky’s financial instability hypothesis but also the off-balance-sheet operations represented by erivative products, which are closely related to mortgage loans. Financial intermediaries in need of liquidity did everything in their power so that the securitization of assets could have a life of its own in financial operations. This is a process that is endogenous to the development of financialization. Because said process was a violation of the monetary economy, it was necessary for central banks to intervene as “lenders of last resort” as well as to nationalize and restructure all the financial intermediaries

Development of a New Alpha Function for the Peng–Robinson Equation of State: Comparative Study of Alpha Function Models for Pure Gases (Natural Gas Components) and Water-Gas Systems

International audienc

Methane and water phase equilibria in the presence of single and mixed electrolyte solutions using the cubic-plus-association equation of State

Methane gas hydrates have been widely touted as a potential new source of energy. Methane hydrate has been found to form in various rocks or sediments given suitable pressures, temperatures, and supplies of water and methane. However, natural subsurface environments exhibit significant variations in formation water chemistry, and these changes create local shifts in the phase boundary. Furthermore, formation water produced with reservoir fluids contains various quantities of salts, which inhibit hydrate formation. Therefore, it is essential to gain a better understanding of the effect of aqueous electrolyte solutions on gas hydrate stability conditions. In this communication, we report new experimental dissociation data for methane simple hydrates in presence of aqueous solutions containing different concentrations of NaCl, KCl and MgCl2. The new data were generated by a reliable fixed-volume, isochoric, step-heating technique. The accuracy and reliability of the experimental measurements are demonstrated by comparing measurements with the literature data. A thermodynamic approach in which the Cubic-Plus-Association Equation of State is combined with a modified Debye Hückel electrostatic term is employed to model the phase equilibria. The hydrate-forming conditions are modeled by the solid solution theory of van der Waals and Platteeuw. To model hydrate phase equilibria in porous media, the effect of capillary pressure has been taken into account. Predictions of the developed model are validated against independent experimental data and the data generated in this work. A good agreement between predictions and experimental data is observed, supporting the reliability of the developed model