Large amplitude fluctuations of confined semiflexible biopolymer filaments

(ii) Modeling and simulations based o

NANO2005-87030 ELASTIC FIELDS OF SURFACE QUANTUM DOTS

ABSTRACT The INTRODUCTION The focus of this research project is to determine the elastic stress fields of three-dimensional self-assembled quantum dots (SAQDs) and the elastic interaction energy between them. In particular, the effect of interaction energy on the spatial ordering of quantum dots is investigated. Both for understanding ordering, as well as the subsequent effects on electronic properties in SAQD structures, several classes of theoretical models have evolved. Romanov et al. In the present study, the purpose is two-fold: firstly, to determine the elastic fields in 3D quantum dots and the surrounding substrate, by means of finite element analysis, in order to assess the effect of lattice mismatch, dot volume, and dot/surface contact area on the induced stress fields and elastic energy. Secondly, to investigate the elastic interaction between quantum dots and the impact of the separation distance between the dots on the in

Transdermal Drug Delivery: Determining Permeation Parameters Using Tape Stripping and Numerical Modeling

The function of transdermal drug delivery (TDD) systems is complex due to the multiple layers necessary for controlling the rate of drug release and the interaction with the patient’s skin. In this work, we study a particular aspect of a TDD system, that is, the parameters that describe the drug permeation through the skin layers. Studies of the diffusion of two compounds were carried out and supported by tape stripping and numerical modeling. The experimental studies are carried out for porcine skin in a Franz diffusion cell and tape stripping is used to quantify the concentration of drug in the stratum corneum. A multi-layered numerical model, based on Fickian diffusion, is used to determine the unknown parameters that define the skin’s permeability, such as the partition between layers and the mass transfer coefficients due to the surface barrier. A significant correlation was found between the numerical modeling and experimental results, indicating that the partition and mass transfer effects at the interlayer boundary are accurately represented in the numerical model. We find that numerical modeling is essential to fully describe the diffusion characteristics