9,485 research outputs found
On the Statistical Foundations of Kaluza's Magnetohydrodynamics
The introduction of electromagnetic fields into the Boltzmann equation
following a 5D general relativistic approach is considered in order to
establish the transport equations for dilute charged fluids in the presence of
a weak electromagnetic field. The conserved 5D stress-energy tensor is
evaluated using the J\"uttner function for non-degenerate relativistic gases in
local equilibrium, and the evolution equations for the local thermodynamic
variables are established by means of relativistic kinetic theory. An outline
of the possibilities offered by the Kaluza-type approach to MHD is also
included.Comment: 10 page
SAFT-γ Force Field for the Simulation of Molecular Fluids 6. Binary and ternary mixtures comprising water, carbon dioxide, and n-alkanes
AbstractThe SAFT-γ coarse graining methodology (Avendaño et al., 2011) is used to develop force fields for the fluid-phase behaviour of binary and ternary mixtures comprising water, carbon dioxide, and n-alkanes. The effective intermolecular interactions between the coarse grained (CG) segments are directly related to macroscopic thermodynamic properties by means of the SAFT-γ equation of state for molecular segments represented with the Mie (generalised Lennard–Jones) intermolecular potential (Papaioannou et al., 2014). The unlike attractive interactions between the components of the mixtures are represented with a single adjustable parameter, which is shown to be transferable over a wide range of conditions. The SAFT-γ Mie CG force fields are used in molecular-dynamics simulations to predict the challenging (vapour+liquid) and (liquid+liquid) fluid-phase equilibria characterising these mixtures, and to study phenomena that are not accessible directly from the equation of state, such as the interfacial properties. The description of the fluid-phase equilibria and interfacial properties predicted with the SAFT-γ Mie force fields is in excellent agreement with the corresponding experimental data, and of comparable if not superior quality to that reported for the more sophisticated atomistic and united-atom models
Spectroscopic Interpretation: The High Vibrations of CDBrClF
We extract the dynamics implicit in an algebraic fitted model Hamiltonian for
the deuterium chromophore's vibrational motion in the molecule CDBrClF. The
original model has 4 degrees of freedom, three positions and one representing
interbond couplings. A conserved polyad allows in a semiclassical approach the
reduction to 3 degrees of freedom. For most quantum states we can identify the
underlying motion that when quantized gives the said state. Most of the
classifications, identifications and assignments are done by visual inspection
of the already available wave function semiclassically transformed from the
number representation to a representation on the reduced dimension toroidal
configuration space corresponding to the classical action and angle variables.
The concentration of the wave function density to lower dimensional subsets
centered on idealized simple lower dimensional organizing structures and the
behavior of the phase along such organizing centers already reveals the atomic
motion. Extremely little computational work is needed.Comment: 23 pages, 6 figures. Accepted for publication in J. Chem. Phy
On the Empirics of Sudden Stops: The Relevance of Balance-Sheet Effects
Using a sample of 32 developed and developing countries we analyze the empirical characteristics of sudden stops in capital flows and the relevance of balance sheet effects in the likelihood of their materialization. We find that large real exchange rate (RER) fluctuations coming hand in hand with Sudden Stops are basically an emerging market (EM) phenomenon. Sudden Stops seem to come in bunches, grouping together countries that are different in many respects. However, countries are similar in that they remain vulnerable to large RER fluctuations – be it because they could be forced to large adjustments in the absorption of tradable goods, and/or because the size of dollar liabilities in the banking system (i.e., domestic liability dollarization, or DLD) is high. Openness, understood as a large supply of tradable goods that reduces leverage over the current account deficit, coupled with DLD, are key determinants of the probability of Sudden Stops. The relationship between Openness and DLD in the determination of the probability of Sudden Stops is highly non-linear, implying that the interaction of high current account leverage and high dollarization may be a dangerous cocktail.
Critical Theoretical Frameworks in Engineering Education: An Anti-Deficit and Liberative Approach
The field of engineering education has adapted different theoretical frameworks from a wide range of disciplines to explore issues of education, diversity, and inclusion among others. The number of theoretical frameworks that explore these issues using a critical perspective has been increasing in the past few years. In this review of the literature, we present an analysis that draws from Freire’s principles of critical andragogy and pedagogy. Using a set of inclusion criteria, we selected 33 research articles that used critical theoretical frameworks as part of our systematic review of the literature. We argue that critical theoretical frameworks are necessary to develop anti-deficit approaches to engineering education research. We show how engineering education research could frame questions and guide research designs using critical theoretical frameworks for the purpose of liberation
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