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The Advection Diffusion-in-Secondary Saturation Movement Equation and Its Application to Concentration Gradient-Driven Saturation Kinetic Flow  [PDF]
Tafireyi Nemaura
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.411200
Abstract: This work describes the deterministic interaction of a diffusing particle of efavirenz through concentration gradient. Simulated pharmacokinetic data from patients on efavirenz are used. The Fourier’s Equation is used to infer on transfer of movement between solution particles. The work investigates diffusion using Fick’s analogy, but in a different variable space. Two important movement fluxes of a solution particle are derived an absorbing one identified as conductivity and a dispersing one identified as diffusivity. The Fourier’s Equation can be used to describe the process of gain/loss of movement in formation of a solution particle in an individual.
Fractional-diffusion-advection limit of a kinetic model  [PDF]
Pedro Aceves-Sanchez,Christian Schmeiser
Mathematics , 2015,
Abstract: A fractional diffusion equation with advection term is rigorously derived from a kinetic transport model with a linear turning operator, featuring a fat-tailed equilibrium distribution and a small directional bias due to a given vector field. The analysis is based on bounds derived by relative entropy inequalities and on two recently developed approaches for the macroscopic limit: a Fourier-Laplace transform method for spatially homogeneous data and the so called moment method, based on a modified test function.
Stacking of oligo and polythiophenes cations in solution: surface tension and dielectric saturation  [PDF]
Damian A. Scherlis,Jean-Luc Fattebert,Nicola Marzari
Physics , 2005, DOI: 10.1063/1.2198811
Abstract: The stacking of positively charged (or doped) terthiophene oligomers and quaterthiophene polymers in solution is investigated applying a recently developed unified electrostatic and cavitation model for first-principles calculations in a continuum solvent. The thermodynamic and structural patterns of the dimerization are explored in different solvents, and the distinctive roles of polarity and surface tension are characterized and analyzed. Interestingly, we discover a saturation in the stabilization effect of the dielectric screening that takes place at rather small values of $\epsilon_0$. Moreover, we address the interactions in trimers of terthiophene cations, with the aim of generalizing the results obtained for the dimers to the case of higher-order stacks and nanoaggregates.
Kinetic, potential and surface tension energies of solitary waves in deep water  [PDF]
Vera Mikyoung Hur
Physics , 2015, DOI: 10.1088/1751-8113/48/42/42FT01
Abstract: We present an exact relation among the kinetic, potential and surface tension energies of a solitary wave in deep water in all dimensions. We deduce its non-existence in the absence of the effects of surface tension, provided that gravity acts in a direction opposite to what is physically realistic.
A Kinetic Approach to the Calculation of Surface Tension in a Spherical Drop  [PDF]
V. Molinari,D. Mostacci,M. Premuda
Physics , 2005,
Abstract: Surface tension in drops has been investigated mainly from a thermodynamic standpoint, more rarely with kinetic methods. In the present work, this problem is studied in the framework of kinetic theory, starting from Sutherland's approximation for Van Der Waals interaction between molecules. Surface tension is calculated as a function of drop radius: it is found that it approaches swiftly an asymptotic value, for radii of several times the intermolecular distance. This theoretical asymptotic value is compared to experimental values for a few liquids, and is found in reasonable agreement.
Colorectal and uterine movement and tension of the inferior hypogastric plexus in cadavers
Ian P Johnson
Chiropractic & Manual Therapies , 2012, DOI: 10.1186/2045-709x-20-13
Abstract: Twenty eight embalmed human cadavers were examined. Pelvic visceral structures were displaced by very gentle 5?N unidirectional tension and the associated movement of the endopelvic fascia containing the inferior hypogastric plexus that this caused was measured.Most movement of the fascia containing the inferior hypogastric plexus was obtained by pulling the rectosigmoid junction or broad ligament of the uterus. The plexus did not cross any vertebral joints and the fascia containing it did not move on pulling the hypogastric nerve.Uterine and rectosigmoid displacement produce most movement of the fascia containing the hypogastric nerve plexus, potentially resulting in nerve tension. In the living this might occur as a consequence of menstruation, pregnancy or constipation. This may be relevant to somatovisceral reflex theories of the effects of manual therapy on visceral conditions.Beneficial effects have been reported for chiropractic and manual therapy treatment of conditions affecting pelvic viscera such as the bowel, bladder and uterus [1-4], although study design often makes meta-analyses difficult [5-7]. In contrast, very little is known about the mechanisms involved. Neural-based theories are often offered as explanations- and sometimes justifications- for treatment [8-10], but there is little human evidence to support them. This weakens the overall rationale for choosing chiropractic and manual therapy protocols for conditions with underlying visceral aetiologies even if outcome studies suggest a benefit. The aim of this study is to test the possibility that movement of pelvic viscera in humans might put mechanical tension on visceral nerves. This may help define the structural basis of some somatovisceral interactions where adverse mechanical tension of nerves is presumed to be operating [8,9]. One likely candidate here is the inferior hypogastric plexus, since it is in close anatomical proximity to- and innervates- much of the pelvic viscera [11,12]. It is
Phase mixing vs. nonlinear advection in drift-kinetic plasma turbulence  [PDF]
A. A. Schekochihin,J. T. Parker,E. G. Highcock,P. J. Dellar,W. Dorland,G. W. Hammett
Physics , 2015,
Abstract: A scaling theory of long-wavelength electrostatic turbulence in a magnetised, weakly collisional plasma (e.g., drift-wave turbulence driven by temperature gradients) is proposed, with account taken both of the nonlinear advection of the perturbed particle distribution by fluctuating ExB flows and of its phase mixing, which is caused by the streaming of the particles along the mean magnetic field and, in a linear problem, would lead to Landau damping. A consistent theory is constructed in which very little free energy leaks into high velocity moments of the distribution, rendering the turbulent cascade in the energetically relevant part of the wave-number space essentially fluid-like. The velocity-space spectra of free energy expressed in terms of Hermite-moment orders are steep power laws and so the free-energy content of the phase space does not diverge at infinitesimal collisionality (while it does for a linear problem); collisional heating due to long-wavelength perturbations vanishes in this limit (also in contrast with the linear problem, in which it occurs at the finite rate equal to the Landau-damping rate). The ability of the free energy to stay in the low velocity moments of the distribution is facilitated by the "anti-phase-mixing" effect, whose presence in the nonlinear system is due to the stochastic version of the plasma echo (the advecting velocity couples the phase-mixing and anti-phase-mixing perturbations). The partitioning of the wave-number space between the (energetically dominant) region where this is the case and the region where linear phase mixing wins is governed by the "critical balance" between linear and nonlinear timescales (which for high Hermite moments splits into two thresholds, one demarcating the wave-number region where phase mixing predominates, the other where plasma echo does).
The kinetic power of jets magnetically accelerated from advection dominated accretion flows in radio galaxies  [PDF]
Shuang-Liang li,Xinwu Cao
Physics , 2010, DOI: 10.1111/j.1745-3933.2010.00859.x
Abstract: There is a significant nonlinear correlation between the Eddington ratio (L_bol=L_Edd) and the Eddington-scaled kinetic power (L_kin=L_Edd) of jets in low luminosity active galactic nuclei (AGNs) (Merloni & Heinz). It is believed that these low luminosity AGNs contain advection dominated accretion flows (ADAFs). We adopt the ADAF model developed by Li & Cao, in which the global dynamics of ADAFs with magnetically driven outflows is derived numerically, to explore the relation between bolometric luminosity and kinetic power of jets. We find that the observed relation, L_kin/L_Edd ~ (L_bol=L_Edd)^0.49, can be well reproduced by the model calculations with reasonable parameters for ADAFs with magnetically driven outflows. Our model calculations is always consistent with the slope of the correlation independent of the values of the parameters adopted. Compared with the observations, our results show that over 60% of the accreted gas at the outer radius escapes from the accretion disc in a wind before the gas falls into the black holes. The observed correlation between Eddington-scaled kinetic power and Bondi power can also be qualitatively reproduced by our model calculations. Our results show that the mechanical efficiency varies from 10^-2 ~ 10^-3, which is roughly consistent with that required in AGN feedback simulations.
Resonance Broadening Induced Nonlinear Saturation of Kinetic Alfven Turbulence in the Interplanetary Plasma  [PDF]
M. V. Medvedev,P. H. Diamond
Physics , 1996, DOI: 10.1016/0375-9601(96)00465-3
Abstract: The saturation of ion cyclotron Alfven turbulence excited by beam particles is investigated using resonance broadening theory. The stochastic scattering which decorrelates particles, includes both random acceleration by electric fields and a turbulent magnetic mirroring effect. Turbulent mirroring is shown to yield non-Gaussian corrections to the orbits even if the random electric and magnetic fields are Gaussian. The predicted steady-state turbulence level exhibits a peaked anglular distribution, with a maximum near Theta ~ 60 degrees.
Surface Tension and Kinetic Coefficient for the Normal/Superconducting Interface: Numerical Results vs. Asymptotic Analysis  [PDF]
James C. Osborn,Alan T. Dorsey
Physics , 1994, DOI: 10.1103/PhysRevB.50.15961
Abstract: The dynamics of the normal/superconducting interface in type-I superconductors has recently been derived from the time-dependent Ginzburg-Landau theory of superconductivity. In a suitable limit these equations are mapped onto a ``free-boundary'' problem, in which the interfacial dynamics are determined by the diffusion of magnetic flux in the normal phase. The magnetic field at the interface satisfies a modified Gibbs-Thomson boundary condition which involves both the surface tension of the interface and a kinetic coefficient for motion of the interface. In this paper we calculate the surface tension and kinetic coefficient numerically by solving the one dimensional equilibrium Ginzburg-Landau equations for a wide range of $\kappa$ values. We compare our numerical results to asymptotic expansions valid for $\kappa\ll 1$, $\kappa\approx 1/\sqrt{2}$, and $\kappa\gg 1$, in order to determine the accuracy of these expansions.
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