Moisture diffusion analysis (MDA) has been developed as a new non-destructive evaluation methodology to monitor the strength degradation of graphite-epoxy composite materials. Studies of composite strength degradation due to high moisture identify reversible strength loss due to current moisture content and irreversible strength loss related to prior moisture exposure with microstructure damage...

1. Introduction Practical applications of zeolites and other nanoporous materials always involve at least two different components, but understanding of multicomponent diffusion in zeolites is limited and experimental data are scarce. The elements of the multicomponent Fickian diffusion tensor for a given system may depend on the total loading of adsorbed molecules, the adsorbed-phase compositi...

Blends of chitosan and biodegradable synthetic aliphatic polyesters (polycaprolactone, poly(butylene succinate), poly[(butylene succinate)-co-adipate], poly[(butylene terephthalate)-co-adipate], and poly(lactic acid)) were injection-molded. These samples were immersed in isotonic solution at 37 degrees C for a period of 60 d. The water uptake and the degradation properties, as measured by the l...

Purpose: To evaluate the mechanism of drug release of a slightly soluble drug (theophylline) from nanocomposite of zeolite (ZLT) or hydrotalcite (HTC) used as drug carrier. Methods: Nanocomposite was prepared with dispersion of either ZLT or HTC as drug carrier and theophylline (THP) as drug in drug to clay ratios of 1:2, 3:4 and 1:1. The formulations were characterized for drug release and loa...

The results of a study environmental ageing on the apparent interfacial shear strength glass fibre–vinyl ester microbond samples are presented. scale related issues estimating water absorption levels in reviewed and discussed solution based Fickian diffusion is given. Interphase microdroplets aged at 23°C was relatively stable up to 6 days exposure after which degradation fairly rapid. Immersio...

Hybrid organic-inorganic films were grown by molecular layer deposition (MLD) with a three-step ABC reaction sequence using (A) trimethylaluminum (TMA), (B) ethanolamine (EA), and (C) maleic anhydride (MA) at 90 °C. Very large steady state mass gains of 1854-4220 ng/(cm(2) cycle) were measured depending on reaction conditions. These mass gains are much larger than typical mass gains for surface...

Oxygen contamination of a polyacrylamide gel (PAG) dosimeter can have a significant detrimental effect upon the performance characteristics of the gel as a dosimeter. Oxygen contamination can occur during preparation, but can also arise from the diffusion of atmospheric oxygen through vessel walls. Even 'trace' amounts of oxygen present in any gaseous space (usually nitrogen filled) between the...

Monte Carlo (MC) simulations of transport in random porous networks indicate that for high variances of the lognormal permeability distribution, the transport of a passive tracer is non-Fickian. Here we model this non-Fickian dispersion in random porous networks using discrete temporal Markov models. We show that such temporal models capture the spreading behavior accurately. This is true despi...

The study was aimed at developing extended release matrix tablets of poorly water-soluble diclofenac sodium and highly water-soluble metformin hydrochloride by direct compression using cashew gum, xanthan gum and hydroxypropylmethylcellulose (HPMC) as release retardants. The suitability of light grade cashew gum as a direct compression excipient was studied using the SeDeM Diagram Expert System...

Tramadol-loaded interpenetrating polymer network (IPN) alginate-gelatin (AG) microgels (MG) were prepared by the chemical cross-linking technique with glutaraldehyde as cross-linking agent and were optimized using response surfaces. A central composite design for 2 factors, at 3 levels each, was employed to evaluate the effect of critical formulation variables, namely the amount of gelatin (X1)...