Velocity Vector Field Optimization in Bioventing

Bioventing is a technology used to remove some kinds of pollutants from the subsoil and it is based on the capability of some bacteria species to biodegrade contaminants. The biochemical reaction requires, among other things, oxygen and, therefore, oxygen is inflated into the subsoil by wells. The mathematical model describes the movement of the different fluids which are present in the subsoil - air, water, pollutants, oxygen and so on - and the bacteria population dynamics.

A Bioventing Mathematical Model Based on Pure Oxygen Injection

A mathematical model and the simulation of subsoil decontamination by bioventing will be presented. The bases for the model construction are the following: (1) the pollutant is considered as immobile and confined in the unsaturated zone; (2) only oxygen is injected in the subsoil by wells; (3) the bacteria acting the pollutant removal are immobile and their growth depends on oxygen and pollutant concentration.

A two-layer model for drug delivery from a transdermal patch

A two-phasemathematical model describing the dynamics of a substance between two coupled media of different properties and dimensions is presented. A system of partial differential equations describes the diffusion and the binding/unbinding processes in both layers. Additional flux continuity at the interface and clearance conditions into systemic circulation are imposed. An eigenvalue problem with discontinuous coefficients is solved and an analytical solution is given in the form of an infinite series expansion.

On the influence of solid-liquid mass transfer in the modelling of drug release from stents

In this paper we present a model of drug release from a drug eluting-stent and the subsequent drug transport in the arterial wall. In order to study the complete process, a two-phase mathematical model describing the transport of a drug between two coupled media of different properties and dimensions is presented. A system of partial differential equations describes both the solid-liquid transfer (dissolution) and diffusion processes in the polymeric substrate as well as diffusion, convection and reaction in the tissue layer.

Subsoil decontamination with bioventing: numerical experiments

A mathematical model describing the bioventing technique for the decontamination of pol- luted subsoil will be presented. Bioventing is a biological technique: bacteria remove the contaminant transforming it and oxygen is consumed in the reaction. The numerical model is based on the fluid flow theory in porous media and bacteria population dynamics and it describes: pollutant degradation, oxygen and bacteria concentration. The mathematical model will be numerically solved and the results of some experiments will be presented.

Nonlinear Langevin model for the early-stage dynamics of electrospinning jets

We present a nonlinear Langevin model to investigate the early-stage dynamics of electrified polymer jets in electrospinning experiments. In particular, we study the effects of air drag force on the uniaxial elongation of the charged jet, right after ejection from the nozzle. Numerical simulations show that the elongation of the jet filament close to the injection point is significantly affected by the nonlinear drag exerted by the surrounding air. These results provide useful insights for the optimal design of current and future electrospinning experiments.

Weitzenböck's torsion, Fermi coordinates, and adapted frames

We study Weitzenböck's torsion and discuss its properties. Specifically, we calculate the measured components of Weitzenböck's torsion tensor for a frame field adapted to static observers in a Fermi normal coordinate system that we establish along the world line of an arbitrary accelerated observer in general relativity. A similar calculation is carried out in the standard Schwarzschild-like coordinates for static observers in the exterior Kerr spacetime; we then compare our results with the corresponding curvature components.