Márcio Sampaio Gomes Filho

arXiv2019

A statistical mechanical model for drug release: relations between release parameters and porosity

A lattice gas model is proposed for investigating the release of drug molecules on devices with semi-permeable, porous membranes in two and three dimensions. The kinetic of this model was obtained through the analytical solution of the three-dimension diffusion equation for systems without membrane and with Monte Carlo simulations. Pharmaceutical data from drug release is usually adjusted to the Weibull function, $\exp [-(t/τ)^b ]$, also known as stretched exponential, and the dependence of adjusted parameters $b$ and $τ$ is usually associated, in the pharmaceutical literature, with physical mechanisms dominating the drug dynamics inside the capsule. The relation of parameters $τ$ and $b$ with porosity $λ$ are found to satisfy, a simple linear relation for between $τ$ and $λ^{-1}$, which can be explained through simple physically based arguments, and a scaling relation between $b$ and $λ$, with the scaling coefficient proportional to the system dimension.

cond-mat.soft↗

arXiv2018

Waterlike anomalies on the Bose-Hubbard Model

Although well-researched as a prototype Hamiltonian for strongly interacting quantum systems, the Bose-Hubbard model has not so far been explored as a fluid system with waterlike anomalies. In this work we show that this model supports, in the limit of a strongly localizing confining potential, density anomalies which can be traced back to ground state (zero-temperature) phase transitions between different Mott insulators. This key finding opens a new pathway for theoretical and experimental studies of liquid water and, in particular, we propose a test of our predictions that can be readily implemented in a ultra-cold atom platform.

cond-mat.stat-mech↗