Suggested Running Head: Application of two-way RC in the assessment of hydrodynamic dispersion 2 ABSTRACT Zones of mixing between shallow groundwaters of different composition were unravelled by " two-way regionalized classification " , a technique based on Correspondence Analysis, Cluster Analysis and Discriminant Analysis, aided by gridding, map-overlay and contouring tools. The shallow groun...

The objective of this work was to develop a fast and significant method for the determination of the intraparticulate pore size distribution of microspheres. Poly(lactide-co-glycolide) (PLGA) microspheres prepared with a solvent extraction/evaporation process were studied. From the envelope and the skeletal volume of the microspheres the porosity was calculated. The skeletal volume was determin...

-In this paper a three-phase model (liquid, solid and gas) of the mushy zone for investigation of porosity formation in solidifying castings is developed. This model takes into account the release of the dissolved gas from the alloy as well as heat transfer and interdendritic fluid flow in the mushy zone. An important aspect of this work is related to accounting for the term describing porosity...

OBJECTIVE To illustrate problems observed with low-porosity expanded polytetrafluoroethylene soft tissue implants and to describe a new dual-porosity implant, the technique for insertion, and this author's preliminary experience. METHOD A review of 175 pieces of SoftForm (Collagen Corporation, Palo Alto, Calif) placed in 69 patients over 3 years was performed. Between October 1, 1997, and Sep...

Zeolites are important materials whose utility in industry depends on the nature of their porous structure. Control over microporosity is therefore a vitally important target. Unfortunately, traditional methods for controlling porosity, in particular the use of organic structure-directing agents, are relatively coarse and provide almost no opportunity to tune the porosity as required. Here we s...

Porosity is a major problem occurring in aluminium alloy casting. During the process of solidification, alloy would shrink and emit dissolving hydrogen causing porosity formation inside the solidified part which leads to mechanical properties degradation. This research aims to produce a formula to explain the resulting porosity with the initial chemical compositions and cooling rate. A mathemat...

The porosity content in composite material is known to innuence the strength of the material. It is therefore of interest to monitor the porosity contents during manufacturing. Since attenuation and porosity are related, traditional porosity determination in composites is performed as attenuation measurements using ul-trasonic tone burst through-transmission. In this paper we propose a multivar...

A hot tear indicator based on the physics of solidification and deformation is presented. This indicator is derived using available data from computer simulation of solidification and solid deformation. Hot tears form when the mushy zone is starved of liquid feeding and deformed in tension. The unfed tensile deformation causes a small additional porosity. A physical model based on a mass balanc...

We introduce a new class of high-porosity microstructures, called “single-scale laminates,” made from arrays of parallel walls. They are extremal, in the sense that no stiffer structure exists with the same total mass. They are simple, in the sense of being easy to describe, and perhaps to manufacture. And they are universal: for any high-porosity microstructure there is a single-scale laminate...

By quantitatively fitting simple emission line profile models that include both atomic opacity and porosity to the Chandra X-ray spectrum of ζ Pup, we are able to explore the trade-offs between reduced mass-loss rates and wind porosity. We find that reducing the mass-loss rate of ζ Pup by roughly a factor of four, to 1.5× 10 M⊙ yr , enables simple non-porous wind models to provide good fits to ...