Elaborate one-dimensional photonic crystals are constructed from a variety of organic and biopolymers, which can be dissolved or melted, by templating the solution-cast or injection-molded materials in porous silicon or porous silicon dioxide multilayer (rugate dielectric mirror) structures. After the removal of the template by chemical dissolution, the polymer castings replicate the photonic f...

abstract porous materials are commonly found in nature and as industrial materials such as wood, carbon, foams, ceramics and bricks. in order to use them effectively, their mechanical properties must be understood in relation to their micro-structures. foam made from non-flammable metal will remain non-flammable and the foam is generally recyclable back to its base material. this research work ...

Atrazine and metolachlor were more strongly retained on earthworm (Lumbricus terrestris L.) castings than on soil, suggesting that earthworm castings at the surface or at depth can reduce herbicide movement in soil. Herbicide sorption by castings was related to the food source available to the earthworms. Both atrazine and metolachlor sorption increased with increasing organic carbon (C) conten...

A numerical model, using the discrete element method, has been developed to quantify specific parameters that are pertinent to the packing behaviour of relatively large, spherical NaCl beads and mixtures of beads of different sizes. These parameters have been compared with porosity and connectivity measurements made on porous aluminium castings made by molten metal infiltration into packed beds...

Casting is an economical way to manufacture parts. On average, complex aerospace castings incur about one-fourth the cost of forgings. However, castings can not be used as primary structure in aircraft because of poor control over design allowables for the material strength and ductility. They can be used as secondary structure, but must include significant safety factors usually between 3 and ...

The Charpy impact energy of A356 alloys has been measured. Instrumented Charpy impact tests have been conducted at 25, 100, 150, and 200 ~ The Charpy specimens were machined from plate castings or tapered cylindrical castings. The plates were produced in sand molds, and tapered cylinders were produced in water-cooled copper molds. Both unmodified and strontium-modified castings were tested. The...

Filtration of mass produced automobile castings is widely and successful applied, less common and more difficult is the filtration of large castings heavier than 1.000 kg. The paper deals with the special problems of applying filtration to such castings including; filter selection, description of three special filtration gating system concepts, along with ten case studies are given.