Destruction of the family of steady states in the planar problem of Darcy convection

The natural convection of incompressible fluid in a porous medium causes for some boundary conditions a strong non-uniqueness in the form of a continuous family of steady states. We are interested in the situation when these boundary conditions are violated. The resulting destruction of the family of steady states is studied via computer experiments based on a mimetic finite-difference approach. Convection in a rectangular enclosure is considered under different perturbations of boundary conditions (heat sources, infiltration). Two scenario of the family of equilibria are found: the transformation to a limit cycle and the formation of isolated convective patterns.Comment: 12 pages, 6 figure

Staggered grids discretization in three-dimensional Darcy convection

We consider three-dimensional convection of an incompressible fluid saturated in a parallelepiped with a porous medium. A mimetic finite-difference scheme for the Darcy convection problem in the primitive variables is developed. It consists of staggered nonuniform grids with five types of nodes, differencing and averaging operators on a two-nodes stencil. The nonlinear terms are approximated using special schemes. Two problems with different boundary conditions are considered to study scenarios of instability of the state of rest. Branching off of a continuous family of steady states was detected for the problem with zero heat fluxes on two opposite lateral planes.Comment: 20 pages, 9 figure

Qualitative versus quantitative data tools for sustainable package design at Eastman Kodak company

Due to the increased sustainability trends in the packaging industry during the last decade and a push from major retailers, in conjunction with the dire economic climate and internal reorganizations within the company, a need for an official design tool was born; a tool that would simplify, unify and improve the design process within the company. Following the creation of the original tool, the Packaging Development and Optimization Tool (PDOT), a critique arose that suggested an addition of LCA data, creating a more quantitatively based tool. A modified design process followed, the Sustainable Packaging Design Tool (SPDT), which utilized LCA data in addition to all other package specifications to recommend a design option with a minimal impact. This study compares the two different packaging design tools. It assumes that a quantitatively based design tool is superior to a qualitatively based tool. It suggests that a quantitative tool can reduce decision-making time, improve satisfaction with design decision and create consistency of results. The research was based on the study and survey of packaging engineers in the company

Properties of Gas Mixtures and Liquid Solutions from Infinite Dilution Studies

Chemical Engineerin

On the flow map for 2D Euler equations with unbounded vorticity

In Part I, we construct a class of examples of initial velocities for which the unique solution to the Euler equations in the plane has an associated flow map that lies in no Holder space of positive exponent for any positive time. In Part II, we explore inverse problems that arise in attempting to construct an example of an initial velocity producing an arbitrarily poor modulus of continuity of the flow map.Comment: http://iopscience.iop.org/0951-7715/24/9/013/ for published versio

The Vortex-Wave equation with a single vortex as the limit of the Euler equation

In this article we consider the physical justification of the Vortex-Wave equation introduced by Marchioro and Pulvirenti in the case of a single point vortex moving in an ambient vorticity. We consider a sequence of solutions for the Euler equation in the plane corresponding to initial data consisting of an ambient vorticity in $L^1\cap L^\infty$ and a sequence of concentrated blobs which approach the Dirac distribution. We introduce a notion of a weak solution of the Vortex-Wave equation in terms of velocity (or primitive variables) and then show, for a subsequence of the blobs, the solutions of the Euler equation converge in velocity to a weak solution of the Vortex-Wave equation.Comment: 24 pages, to appea

Vanishing viscosity limits for the degenerate lake equations with Navier boundary conditions

The paper is concerned with the vanishing viscosity limit of the two-dimensional degenerate viscous lake equations when the Navier slip conditions are prescribed on the impermeable boundary of a simply connected bounded regular domain. When the initial vorticity is in the Lebesgue space $L^q$ with $2<q\le\infty$, we show the degenerate viscous lake equations possess a unique global solution and the solution converges to a corresponding weak solution of the inviscid lake equations. In the special case when the vorticity is in $L^\infty$, an explicit convergence rate is obtained

Moser functions and fractional Moser-Trudinger type inequalities

We improve the sharpness of some fractional Moser-Trudinger type inequalities, particularly those studied by Lam-Lu and Martinazzi. As an application, improving upon works of Adimurthi and Lakkis, we prove the existence of weak solutions to the problem $(-\Delta)^\frac{n}{2}u=\lambda ue^{bu^2} \,\text{ in }\Omega,\, 00,$ with Dirichlet boundary condition, for any domain $\Omega$ in $\mathbb{R}^n$ with finite measure. Here $\lambda_1$ is the first eigenvalue of $(-\Delta)^\frac n2$ on $\Omega$

On the 2D Isentropic Euler System with Unbounded Initial vorticity

37 pagesThis paper is devoted to the study of the low Mach number limit for the 2D isentropic Euler system associated to ill-prepared initial data with slow blow up rate on $\log\varepsilon^{-1}$. We prove in particular the strong convergence to the solution of the incompressible Euler system when the vorticity belongs to some weighted $BMO$ spaces allowing unbounded functions. The proof is based on the extension of the result of \cite{B-K} to a compressible transport model