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Showing 1 to 18 of 18 for “"non-Fickian"”.
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Quantifying non-Fickian transport in porous and fractured media using fractional-calculus based stochastic models
Non-Fickian or “anomalous” transport, where the target’s spatial variance grows nonlinearly in time, describes the pollutant dynamics widely observed in heterogeneous geological media deviating significantly from that described by the classical advection dispersion equation (ADE). The ADE describes …
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An unstructured finite volume simulator for multiphase flow through fractured-porous media
… transport through fractured media. The non-Fickian transport resulting due to the presence of heterogeneity (as fractures or inhomogeneous permeability distribution) is captured by the traditional advection-diffusion equation using a highly discretized system. Today. many macroscopic …
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Novel Biomimetic Polymeric Nanoconjugates as Drug Delivery Carriers for Poorly Soluble Drugs
… a higher release profile than ibuprofen control. Fickian and non-Fickian anomalous mechanisms were deduced for the drug release of ibuprofen from the binary conjugates. The ternary nanoconjugates exhibited non-Fickian (anomalous) diffusion, Fickian diffusion and Super Case II transport release …
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Use of hydraulic tests to identify conceptual models of heterogeneity for fractured rock aquifers
… flow geometry. Previous studies have reported non-integer flow dimensions for a number of aquifers and reservoirs of various rock types, suggesting that flow is dominated by a series of fractal channels [Acuna and Yortsos, 1995]. Typically, the information carried by the flow dimension is …
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Heterogeneity effects on flow and transport within a shallow fluvial aquifer
… consistent with the bedding direction as well as non-Fickian transport rates.
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Studies of water vapor transport and sorption in wood
… Some first results on sorption in spruce wood. Non-Fiction behavior is seen above 75% relative humidity. 3. In this part the main experimental results are presented. At lower relative humidity (absorption from 54 to 75%) the normally used Fiction approach can describe the major part of the …
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Characterisation of cross-linking and moisture ingress detection in an epoxy/amine resin using fibre-optic sensors
… diffusion of moisture in the neat-resin showed non-Fickian behaviour.
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The durability of adhesive joints: an engineering study
… stress dependence of solubility as well as the non-fickian driving forces contributing to mass transport are predicted from the Flory-Huggins theory. Experimental validation of the concentration dependence and temperature dependence of the diffusion coefficient is shown. The effect of mechanical …
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Improved predictions of contaminant transport in rivers
… average of 17%. The proposed method mimics the non-Fickian behavior of the transport observed in rivers while avoiding the computational cost and data requirements of more complex models.</p>
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Amorphous calcium phosphate nanocomplexes in dental film formulations
… and was best described by a Higuchi mode with Fickian, non-Fickian and super case II transport kinetics depending on the type of ACP and the grade of HPMC used. The effect of a biofilm generated on the tooth surface to make the substrate more hydrophobic was examined. The adhesion of 15% (w/v) …
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Multiscale modeling of moisture transport coupled with quality changes in selected foods
… in sharper moisture profiles, indicating non-Fickian transport. Especially the boundaries due to lower moisture content in these regions underwent glass transition during the drying process, which affected the textural properties. Similar to experimental results, it was found that higher …
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Electrospun membranes for implantable glucose biosensors
… strength. Very thin membranes showed zero-order (Fickian diffusion exponent ‘n’ ~ 1) permeability for glucose transport. Increasing membrane thickness lowered ‘n’ value through non-Fickian towards Fickian (‘n’ = 0.5) diffusion. Thin electrospun PU membranes (~10 μm thick) did not affect, while …
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Development and evaluation of amphotericin B Loaded iron oxide nanoparticles for targeted drug delivery to systemic fungal infections
… from these formulations were determined to be Fickian and non-Fickian diffusion with first order and Higuchi kinetic models as best fit. </p> <p>The cellular uptake profile for design D exhibited a time dependent uptake with maximum uptake at 0.5 and 4 hours for C. albicans and C. glabrata, …
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The effect of nanoclays on the properties of aspirin modified enteric polymer prepared by hot-melt mixing
… requirements and the API release mechanism is non-Fickian. In the second system, polymer nanocomposites are produced by incorporating a nanoclay, hydrotalcite (HT). The morphology of HT in the nanocomposites, originally a multilayer structure, is significantly changed with increasing ASP …
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Vibrational Spectroscopic Studies of Degradation and Diffusion Processes in Poly(ethylene terephthalate)
… The diffusion was shown to be classically Fickian in nature and the diffusion coefficients decreased with increased polymer crystallinity for both sets offilms. The perturbation of the v(OH) band of the water in the polymer matrix was studied as both a function oftime (i.e. concentration) …
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Effect of roughness, microstructure, and chemistry on the environmental durability of structural alloys
… NiCr further accelerates Al diffusion through a non-Fickian mechanism involving Al clustering. The baseline fouling and corrosion behavior of ferrous alloys in a high temperature, high pressure, and an asphaltenic environment was also evaluated. Key insights were generated on the interplay …
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Characterisation of drug loaded insoluble polymeric matrices prepared by hot melt extrusion technology for drug delivery applications.
… showed that the polymer exhibited anomalous non-Fickian transport behaviour where the rate of inward diffusion was approximately equal to the rate of polymer chain relaxation. Water ingress resulted in plasticization of the polymer causing changes in the viscoelastic properties of the …
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Stochastic modelling of contaminant transport in porous media
… However, with changing drift velocity e.g. in a non-homogenous porous medium, new effects emerge. A study of kinematical dispersion produced by advection is used to show that there are intrinsically stochastic effects, characterised as interaction between microscopic stochastic fluctuations and …