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 ...

In the current paper, a low-Si aluminium alloy (1.4-2.4% Si) was used to fabricate a complex shape telecom component using Semi-Solid High-Pressure Die Cast (SSM-HPDC), process. Microstructure and fracture characteristics were investigated. The cast material exhibited microstructural inhomogeneity, in particular macrosegregation in the form of liquid surface segregation bands in addition to sub...

The aluminum bronze matrix alumina composites using hot press and resin infiltration were investigated to study their porosities, hardness, bending strengths, and microstructures. The experiment results show that the hardness of the sintered composites with the decrease of porosity increases. The composites without and with resin infiltration have about HRF 42-61 of about 34-40% of porosity and...

Tissue engineering holds great promise for regeneration and repair of diseased tissues, making the development of tissue engineering scaffolds a topic of great interest in biomedical research. Because of their biocompatibility and similarities to native extracellular matrix, hydrogels have emerged as leading candidates for engineered tissue scaffolds. However, precise control of hydrogel proper...

In this paper, convective dominated diffusion process in an axisymmetric tube with a local constriction simulating a stenosed artery considering the porosity effects is carried out. The investigations demonstrate the effects of wall shear stress and recirculating flow on the concentration distribution in the vessels lumen and on wall mass transfer keeping the porosity in view. The flow is gover...