The dissolution of polymer-coated, controlled-release urea fertilisers by means a simple, Fickian diffusion-based model is described. This in contrast to prior contributions that invoke non-Fickian mechanisms or take more quantitative view. Within quasi-static approximation, simple expressions for the granule radius and release profile as function time are obtained terms experimentally accessib...

The aim of the current investigation is to study the kinetics of drug release pattern from buccal swellable, controlled release tablets of amoxicillin trihydrate. Buccal tablets were prepared with modified gum karaya in 5-20% concentration. Drug release from the formulated amoxicillin trihydrate loaded buccal tablets followed Zero order kinetics resulting in regulated and controlled release for...

In single phase flow of a passive tracer through heterogeneous porous media, a mixing layer develops between the tagged and untagged regions of the fluid. The mixing region expands as the time evolves. We have developed a multilength scale theory for the growth of the mixing region induced by a general random velocity field (multi-fractal field). The theory relates the statistics of the mixing ...

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We performed fluorescence correlation spectroscopy measurements to assess the long-time self-diffusion of a variety of spherical tracer particles in periodic porous nanostructures. Inverse opal structures with variable cavity sizes and openings in the nanometer domain were employed as the model system. We obtained both the exponent of the scaling relation between mean-square displacement and ti...

We describe experiments using single-particle tracking in which mean-square displacement is simply proportional to time (Fickian), yet the distribution of displacement probability is not Gaussian as should be expected of a classical random walk but, instead, is decidedly exponential for large displacements, the decay length of the exponential being proportional to the square root of time. The f...

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been used to investigate the effects of three fatty acid esters on skin permeation. Propylene glycol diperlargonate (DPPG), isopropyl myristate (IPM) and isostearyl isostearate (ISIS) were selected as pharmaceutically relevant solvents with a range of lipophilicities and cyanophenol (CNP) was used as a model dru...

In this article we describe a novel, phenomenologically based computer simulation approach for studying relaxation dynamics in fluid systems. The method utilizes an ensemble consisting of two isothermal chambers initially separated by an impermeable partition. The fluid configurations in each chamber are initially pre-equilibrated at densities r̄1« and r̄2« respectively, where r̄ reflects an avera...

Regional-scale groundwater quality degradation from nonpoint source pollution threatens the long-term sustainability of major alluvial aquifer-aquitard systems worldwide. Models are needed to simulate regionally upscaled transport processes in heterogeneous geology that produces non-Fickian (anomalous) transport. In this investigation, we show impact nonhorizontal and nonvertical mean flow dire...