Woo Hyoung Lee

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In the highly competitive world, there has been a concomitant increase in the need for the research and planning methodology, which can perform an advanced assessment of technological opportunities and an early perception of threats and possibilities of the emerging technology according to the nation’s economic and social status. This research is aiming to(More)
Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct biofilm monochloramine measurement. This study compared free chlorine and(More)
In order to alleviate a flooding problem of the upper catchment area, it was proposed to construct a drainage channel across the fishponds of Inner Deep Bay which were considered as having high ecological value particularly for wetland birds. The potential loss of 34.6 ha of fishponds, which would be converted into the footprint of the drainage channel, was(More)
The efficiency of monochloramine disinfection was dependent on the quantity and composition of extracellular polymeric substances (EPS) in biofilms, as monochloramine has a selective reactivity with proteins over polysaccharides. Biofilms with protein-based (Pseudomonas putida) and polysaccharide based EPS (Pseudomonas aeruginosa), as well as biofilms with(More)
Chloramine has replaced free chorine for secondary disinfection at many water utilities because of disinfection by-product (DBP) regulations. Because chloramination provides a source of ammonia, there is a potential for nitrification when using chloramines. Nitrification in drinking water distribution systems is undesirable and may result in degradation of(More)
The determination of phosphate has been of great importance in the fields of clinical, environmental, and horticultural analysis for over three decades. New cobalt-based micro-electro mechanical systems (MEMS) microelectrode array (MEA) sensors for direct measurement of phosphate in small environmental samples, such as microbial aggregates, has been(More)
The in situ monitoring of phosphate has been of great importance in many environmental applications, particularly those involving biological treatment processes and eutrophication monitoring. A microelectrode with small tip size (~10 mum) was fabricated with cobalt wire, characterized and evaluated for in situ and in vivo environmental analysis of phosphate(More)
Chemically stabilized emulsions are difficult to break because of micelle stability. Many physical and chemical processes have been used for emulsion breaking/separation; however, most operational parameters are based on empirical data and bulk analysis. A multiscale understanding of emulsions is required before these processes can advance further. This(More)
A graphene-based nanosensor was developed for in situ monitoring of polycyclic aromatic hydrocarbons (PAHs) in aqueous solutions. The sensor was fabricated using photolithography and etching of Au/Ti film on a silicon wafer followed by the transfer of a single graphene layer which was prepared separately by chemical vapor deposition (CVD). The performance(More)