Hierarchical Structured Polyimide–Silica Hybrid Nano/Microfiber Filters Welded by Solvent Vapor for Air Filtration

Filtration artifacts caused by overloading membrane filters.

The conventional practice of using 0.45 or 0.40 microm membranes to distinguish between the particulate and dissolved phases in natural waters neglects the importance of colloids. Many of the colloids in natural waters pass through 0.45 or 0.40 microm membranes, but a significant fraction at the upper end of the colloidal particle size range is retained. Membrane clogging during filtration decr...

On Hybrid Synthesis for Hierarchical Structured Petri Nets

We propose a hybrid method for synthesis of hierarchical structured Petri nets. In a top-down manner, we decompose a system into a set of subsystems at each level of abstraction, each of these is speciied as a blackbox Petri net that has multiple inputs and outputs. We stipulate that each subsystem satisses the following I/O constraints: (1) At any instance of time, at most one of the inputs ca...

A Process for Solvent Welded Rapid Prototype Tooling

Rapid prototyping is widely seen as an effective tool for compressing time to market for new products. The typical process followed by industrial and mechanical design groups is to model a new product in a CAD system, rapidly prototype the component parts, use the parts as patterns for RTV silicone molds, and then cast polyurethane prototype parts from the molds. These prototype components are ...

Hierarchical Hybrid Control for Innovative Air-conditioning Equipment

This paper describes the control system for innovative air-conditioning equipment, in particular an air treatment unit. The most important characteristic of the equipment is to be “friend of the environment”, in the sense that it does not use environmentally aggressive refrigerating fluids. Other main characteristic is associated with the complexity of its control, due to the large number of in...

Filters and Filtration