We investigate the influence of volume viscosity on a planar shock/hydrogen bubble interaction. The numerical model is two dimensional and involve complex chemistry and detailed transport. All transport coefficients are evaluated using algorithms which provide accurate approximations rigourously derived from the kinetic theory of gases. Our numerical results show that volume viscosity has an im...

In this paper we study the controllability of an artificial advection-diffusion system through the boundary. Suitable Carleman estimates give us the observability on the adjoint system in the one dimensional case. We also study some basic properties of our problem such as backward uniqueness and we get an intuitive result on the control cost for vanishing viscosity. Introduction Artificial adve...

We compare the physical potential V(D)(R) of an external quark-antiquark pair in the representation D of SU(N), to the color-Coulomb potential V(coul)(R) which is the instantaneous part of the 44-component: of the gluon propagator in Coulomb-gauge D44(x-->,t)=V(coul)(|x-->|)delta(t)+(noninstantaneous). We show that if V(D)(R) is confining, lim(V(D)(R)=+ infinity, as is believed to hold in the a...

Using a proposal of Maldacena one describes the large N limit of gauge theories in terms of supergravity solutions on anti-de Sitter space. From this point of view we discuss a possible scenario for quark confinement in gauge theory by describing hadrons as strongly curved universes. In particular an interpretation of black hole as a bag model in SQCD is discussed. One relates the mystery of cu...

An elastic membrane stretched between two walls takes a shape defined by its length and the volume of fluid it encloses. Many biological structures, such as cells, mitochondria and coiled DNA, have fine internal structure in which a membrane (or elastic member) is geometrically 'confined' by another object. Here, the two-dimensional shape of an elastic membrane in a 'confining' box is studied b...

We have developed a statistical theory for columnar aggregates of semi-flexible polyelectrolytes. The applicability of previous, simplified theories was limited to polyelectrolytes with unrealistically high effective charge and, hence, with strongly suppressed thermal undulations. To avoid this problem, we utilized more consistent approximations for short-range image-charge forces and steric co...

We have mapped two regions at the northern tip of the Magellanic Stream in neutral hydrogen 21-cm emission using the Arecibo telescope. The new data are used to study the morphology and properties of the Stream far away from the Magellanic Clouds, as well as to provide indirect constraints on the properties of the Galactic Halo. We investigate confinement mechanisms for the Stream clouds and co...