Papers by Author: C.L. Chang

Abstract: This work used FDS to simulate tunnel fires occur in a semi-circular longitudinally ventilated tunnel. By varying the parameters such as the tunnel gradient, the fire size, and the ventilation velocity, their influence on the backlayering effect and downstream propagation rate can be recognized. Under weak ventilation, the backlayering effect either advances or vanishes depending on the slope of the tunnel. Under stronger ventilation, the backlayering effect would break up. The temperature distributions may become less and less dependent on the tunnel gradient when the ventilation velocity is increased. Although the hot gases and smoke in uphill tunnels propagate faster than those in downhill tunnels, their difference reduces with ventilation velocity.

Abstract: This paper presents an experimental investigation on the use of high-resolution injection techniques to deliver sample plugs within electrophoresis microchips. Two novel injection microfluidic chips are proposed, which employ conventional cross-shaped and U-shaped injection system combined with an expander to deliver high-quality sample plugs for detection in separation channel. The valving characteristics on microfluidic devices are controlled through appropriate manipulations of the electric potential strengths during the sample injection and separation steps. These novel injection techniques developed in this study has an exciting potential for use in high-quality, high-throughput chemical analysis applications and in many other applications throughout the field of micro-total-analysis systems.