As the most exposed point of contact with the external environment, the skin is an important barrier to many chemical exposures, including medications, potentially toxic chemicals and cosmetics. Traditional dermal absorption models treat the stratum corneum lipids as a homogenous medium through which solutes diffuse according to Fick's first law of diffusion. This approach does not explain non-...

Microstructural banding is defined as alternating layers of two different microstructures in steel, often ferrite and pearlite. It is caused by fluctuations in the concentration of alloying elements, primarily manganese, due to microsegregation introduced during solidification. In this thesis, a model is presented to simulate banding using phase transformation kinetics theory. An existing progr...

A new phenomenological model for interpreting the effects of solutes on biological equilibria is presented. The model attributes changes in equilibria to differences in the desolvation energy of the reacting species that, in turn, reflect changes in the free energy of the bulk water upon addition of secondary solutes. The desolvation approach differs notably from that of other solute models by ...

We have contrasted the behavior of nanoparticles formed by the self-assembly of polymers based on poly(ethylene glycol) (PEG) and poly(D,L-lactide), with linear, linear-dendritic and bottle-brush architectures in biologically relevant media. Polymer PEG content ranged between 14% and 46% w/w, and self-assembly was triggered by a rapid and large change in solvent quality inside a four-stream vor...

Chang, Hangil, and Toshiro Fujita. A numerical model of the renal distal tubule. Am. J. Physiol. 276 (Renal Physiol. 45): F931–F951, 1999.—A numerical model of the rat distal tubule was developed to simulate water and solute transport in this nephron segment. This model incorporates the following: 1) Na-Cl cotransporter, K-Cl cotransporter, Na channel, K channel, and Cl channel in the luminal m...

A general set of methods is presented for calculating chemical potentials in solid and liquid mixtures using ab initio techniques based on density functional theory ~DFT!. The methods are designed to give an ab initio approach to treating chemical equilibrium between coexisting solid and liquid solutions, and particularly the partitioning ratios of solutes between such solutions. For the liquid...

A numerical model of the rat distal tubule was developed to simulate water and solute transport in this nephron segment. This model incorporates the following: 1) Na-Cl cotransporter, K-Cl cotransporter, Na channel, K channel, and Cl channel in the luminal membrane; 2) Na-K-ATPase, K channel, and Cl channel in the basolateral membrane; and 3) conductances for Na, K, and Cl in the paracellular p...

• Salt permeability of polyamide RO membranes is invariant in a wide salinity range. The solution diffusion model adequately describes our seawater membranes. Membrane leaks may cause correlation between and observed salt permeability. New developments modeling solute transport reverse osmosis (RO) are based on the mechanistic description friction electromigration. In these models, membrane cha...