The weak formulation of moving boundary problems with possibly vanishing specific heat, that is governed by parabolic and/or elliptic differential equations, is developed. The uniqueness of the resulting weak solution is then proved. This approach is used to obtain numerical solutions to some physical examples, which arise in electrochemical machining processes, and in saturated / unsaturated f...

PURPOSE The aim of this study was to evaluate early morphofunctional response of contact tissue to pure and saturated with lidocaine porous synthetic HAp ceramic implants inserted in holes of rabbit upper jaw. MATERIALS AND METHODS Pure and saturated with lidocaine cylinders of porous HAp ceramics produced at Biomaterials R&D Laboratory of Riga Technical University were inserted into edentulo...

The biological factors important in the penetration of Escherichia coli through anaerobic, nutrient-saturated, Ottawa sand-packed cores were studied under static conditions. In cores saturated with galactose-peptone medium, motile strains of E. coli penetrated four times faster than mutants defective only in flagellar synthesis. Motile, nonchemotactic mutants penetrated the cores faster than di...

Nanofabrication by self-organization methods has attracted much attention owing to the fact that it enables mass production without the use of expensive lithographical tools, such as an electron beam exposure system. Porous alumina can be fabricated electrochemically through anodic oxidation of aluminum by means of such a self-organization method, yielding highly ordered arrays of nanoholes sev...

Chemotaxis, the microorganisms autonomous motility along or against the concentration gradients of a chemical species, is an important, yet often neglected factor controlling the transport of bacteria through saturated porous media. For example, chemotactic bacteria could enhance bioremediation by directing their own motion to residual contaminants trapped in low hydraulic conductive zones of c...

Th is article examines the status of submersible reference electrodes and presents a new design concept for submersible copper/copper sulfate (Cu/CuSO4) electrodes (CSE). In the new concept, the half-cell potential is independent of the salinity (chlorinity) of the electrolyte, the electrode is not subject to contamination, and structure-to-electrolyte voltages do not require correction to the ...

The general theory for small dynamic motion superimposed upon large static deformation, or acoustoelasticity, is developed for isotropic fluid-filled poroelastic solids. Formulas are obtained for the change in acoustic wave speeds for arbitrary loading, both on the frame and the pore fluid. Specific experiments are proposed to find the complete set of third-order elastic moduli for an isotropic...

Using Biot's theory, a set of boundary conditions is presented for wave transmission and reflection at the contact surface between an elastic medium (fluid or solid) and a fluid-saturated porous solid (Biot medium). The analysis shows the continuity of the normal component of the density energy flux vectors across the contact surfaces, so that total energy is preserved. Energy reflection and tr...

A conceptual model for colloid transport is developed that accounts for colloid attachment straining, and exclusion. Colloid attachment and detachment is modeled using first-order rate expressions, whereas straining is described using an irreversible first-order straining term that is depth dependent. Exclusion is modeled by adjusting transport parameters for colloid-accessible pore space. Fitt...