Preliminary Assessment of Debris Flow Hazard in a Catchment under Extreme Condition

Due to hilly terrain and frequent heavy rainstorms, debris flow is one of the most common and catastrophic hazards in Hong Kong. To mitigate the debris flow risk, prediction of the magnitude and consequence of debris flow is essential. The objective of this paper is to simulate debris flow hazards in a study area in Hong Kong. Assessment of the...

Stimulated-healing of proton exchange membrane fuel cell catalyst

Platinum nanoparticles, which are used as catalysts in Proton Exchange Membrane Fuel Cells (PEMFC), tend to degrade after long-term operation. We discriminate the following mechanisms of the degradation: poisoning, migration and coalescence, dissolution, and electrochemical Ostwald ripening. There are two ways to tackle this problem. The first...

Self crack healing induced by high temperature oxidation in SiN/SiC nano-laminated film

In bulk, Si3N4 reinforced by dispersing SiC particle has superior self crack healing ability at high temperature. In consideration with this fact, SiN/SiC nano-laminated film is expected to exhibit the self crack healing at high temperature. In this study, we investigated the self crack healing behavior of the SiN/SiC nano-laminated film...

Numerical Methods for Reacting Gas Flow Simulations

In this study various numerical schemes for simulating 2D laminar reacting gas flows, as typically found in Chemical Vapor Deposition (CVD) reactors, are proposed and compared. These CVD systems are generally modeled by means of many stiffly coupled elementary gas phase reactions between a large number of reactants and intermediate species. The...

Functional Imaging of Respiratory System Using Computational Fluid Dynamics

Functional imaging of the respiratory system is a new domain where the respiratory dynamics (such as airflow in the lungs and particle deposition) are studied by means of modern engineering techniques. A three dimensional model of a patient specific bronchial tree is constructed from a computed tomography scan. By segmenting the desired region...

High temperature silicon carbide chemical vapor deposition processes: From pure thermodynamic to mass transport modeling

Over the last twenty years, processes which lead to materials synthesis from a gaseous phase constitute an important technology in many applications fields such as microelectronics or protective coating industry. Due to the complexity of the involved phenomena, computational modeling had been required to improve technological processes and help...