Approximation in area of continuous graphs

Summary We prove that graphs of continuous maps with finite area can be approximated weakly as currents and in area by graphs of smooth maps.This article was processed by the author using the style filepljour1m from Springer-Verlag.     

EQUILIBRIUM MODELING OF PSEUDOMONAD AGGREGATION AND PARTITIONING TO DOLOMITE†

Bioremediation is a common treatment technology considered for the remediation of many toxic and hazardous waste sites. In order for this technology to be successfully implemented, the mobility and adhesion characteristics of the microorganisms must be understood. This study explored the surface and adhesion characteristics of two pseudomonads: Pseudomonas aeruginosa Olin and P. fluorescens rib:lux. In general, the Lewis acid/base character of these microorganisms dominated surface thermodynamics. In both cases partitioning to dolomite, a common mineral, was predicted to be greatest in the stationary phase. In the log growth and decay phases, the Lewis acid/base interaction energy was repulsive for both organisms. The stationary phase for both microbes exhibited a reversal of the Lewis acid/base energy to attractive. Although the magnitude of the various surface energy components differed between the microorganism, it is remarkable that the Lewis acid/base energy exhibited similar behavior.     

Matrix-assisted pulsed laser evaporation of chemoselective polymers

The numerous properties of liposomes, i.e., nontoxicity, biodegradability, and their ability to encapsulate different biological active substances in aqueous and lipid phase, make them perfect models of biomembranes. Liposomes made up of phospholipids may be used to study new applications such as cell targeting or, under specific experimental conditions, may be applied in micro and nano-sized biosensors.     

A reduction approach for determining generalized simple waves

A reduction approach is developed in order to construct generalized simple wave solutions to quasilinear nonhomogenous hyperbolic systems of first order PDEs. The solutions sought must possess a special ansatz which permits time-evolution of the profile of a simple wave due to a source-like term. These solutions involve a free function which can be used to fit classes of initial or boundary value problems. By means of the proposed approach two governing models of interest in a variety of applications are investigated. Model constitutive laws consistent with the full reduction process are obtained and the occurence of singularities at a finite time for the resulting solutions is analysed. Furthermore a comparison is made between the results obtained within the present theoretical framework and the standard simple wave solutions of the corresponding homogeneous (source free) governing models.     

On projective spaces PG(r, q) with r ≥ 4

In this paper a characterization of PG(r, q), r ≥ 4, in terms of planar spaces is given. Domenico Olanda: This research was carried out within the activity of INdAM-GNSAGA and supported by the Italian Ministry M.I.U.R.     

Y-junction of superconducting Josephson chains

We show that, for pertinent values of the fabrication and control parameters, an attractive finite coupling fixed point emerges in the phase diagram of a Y-junction of superconducting Josephson chains. The new fixed point arises only when the dimensionless flux f piercing the central loop of the network equals π   and, thus, does not break time-reversal invariance; for f≠π$f\ne \pi$, only the strongly coupled fixed point survives as a stable attractive fixed point. Phase slips (instantons) have a crucial role in establishing this transition: we show indeed that, at f=π$f=\pi$, a new set of instantons—the W-instantons—comes into play to destabilize the strongly coupled fixed point. Finally, we provide a detailed account of the Josephson current–phase relationship along the arms of the network, near each one of the allowed fixed points. Our results evidence remarkable similarities between the phase diagram accessible to a Y-junction of superconducting Josephson chains and the one found in the analysis of quantum Brownian motion on frustrated planar lattices.     

A Note on Strong Ellipticity in Two-Dimensional Isotropic Elasticity

Based on the choice of two physically meaningful strain measures, we study necessary and sufficient conditions for strong ellipticity of the equilibrium equations for two-dimensional isotropic hyperelastic bodies. Specifically, we show, depending on the values of the derivatives of the energy function, that strong ellipticity is equivalent to a single condition with a clear physical interpretation.