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Quadruple Points (quadruple + point)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

PSRK method for gas hydrate equilibria: I. Simple and mixed hydrates

AICHE JOURNAL, Issue 1 2004
Ji-Ho Yoon
Abstract A thermodynamic model using the predictive Soave-Redlich-Kwong (PSRK) group contribution method to calculate the fugacities of all components in the vapor and liquid phases in equilibrium with the coexisting hydrate phase is proposed. Since the PSRK method together with the UNIFAC model takes the gas,gas interaction in the vapor and liquid phases into account, the phase equilibria of mixed gas hydrates can be successfully reproduced. This approach greatly improves upon the accuracy of the modified Huron-Vidal second-order (MHV2) model, especially for three-guest hydrate systems. Based on experimentally determined X-ray data, an accurate representation for the molar volume of the structure I (sI) hydrate is provided and used for predicting the equilibrium dissociation of methane hydrate at high pressures. Using this correlation, it is possible to reduce noticeable errors in dissociation predictions of high-pressure hydrate formers. Complete phase behavior, including a new quadruple point, which is predicted to be 272.6 K and 7.55 MPa, for cyclopropane hydrate, is presented by the proposed model calculation. © 2004 American Institute of Chemical Engineers AIChE J, 50: 203,214, 2004 [source]

Theory of electronic and transport properties of resonant triple quantum dot molecules

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2009
Y.-P. Shim
Abstract We present a theory of electronic and transport properties of triple quantum dot molecules in the vicinity of quadruple points where four different charge configurations are on resonance. We study three different quadruple points in the presence of a magnetic field and show that a trapped particle in one of the dot plays an essential role in determining the spin character of the transport. Many-electron states of the triple quantum dot molecules are used as transport channels in the Fermi's Golden Rule approach and it is demonstrated that the Aharonov,Bohm oscillations of the energy spectrum lead to spin-selective oscillations in transport. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Coincidence site lattice theory of multicrystalline ensembles

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2001
V. Y. Gertsman
It is shown how the coincidence site lattice theory, developed originally for grain boundaries and extended recently to triple junctions, can be applied to more complex ensembles of crystallites with the cubic crystal structure. These include quadruple points, multiple junctions of grains and other multicrystal assemblies. Application of the theory is demonstrated on hypothetical examples, which may help elucidate some practically important problems. [source]