Jangseop Han

• Yonsei University

We present a portable, inexpensive, and accurate microelectromechanical-system-based (MEMS-based) condensation particle counter (CPC) for sensitive and precise monitoring of airborne ultrafine particles (UFPs) at a point of interest. A MEMS-based CPC consists of two main parts: a MEMS-based condensation chip that grows UFPs to micro-sized droplets...

If a steam generator tube rupture (SGTR) occurs during a severe accident in a nuclear power plant, radionuclides can be released to the atmosphere as an aerosol. The release of radioactive compounds can be prevented if these compounds are deposited on the tube walls. To quantify the fraction of aerosol particles retained in the SG and to effectivel...

To monitor airborne nanoparticles at a particular point of interest sensitively and accurately, we developed a compact and inexpensive but highly-precise nanoparticle detection system. The proposed system, based on nucleation light-scattering, consists of two components: a microelectromechanical system (MEMS)-based particle growth chip that grows n...

We present a microelectromechanical system (MEMS)-based condensation particle counter (CPC) for sensitive and precise monitoring of airborne ultrafine particles (UFPs) at a point of interest that is portable, inexpensive, and accurate. The proposed system consists of two main parts: a MEMS-based condensation chip that grows UFPs to micro-sized drop...

A MEMS-based particle detection system which includes a particle processing chip and electronic circuits was developed for low-cost and ubiquitous monitoring of airborne ultrafine particles. The detection system consists of particle classification, charging, precipitation, and sensing sections. Particles with different sizes enter the ultrafine par...

To achieve real-time monitoring of aerodynamic submicron particle size distributions at a point-of-interest, we developed a high-performance particle size spectrometer that is compact, low-cost, and portable. The present system consists of four key components: a unipolar mini-discharger for electrically charging particles, an inertial size-separato...

Increasing public concern regarding air quality has led to the development of efficient aerosol-monitoring techniques. Among the various aerosol measurement instruments based on electrical methods, in this study, an electrical cascade impactor (ECI) was designed and fabricated in our laboratory and was used to measure the real-time size distributio...

Airborne particulate matter is an important factor in the quality of an indoor environment. In this study, a miniaturized particle sensor was developed to detect submicron-sized aerosols based on number counting. This particle number (PN) sensor was designed and fabricated for real-time measurement of total aerosol number concentration and geometri...

For rapid and effective detection of airborne microorganisms, it is preferable to remove dust particles during the air sampling process because they can reduce the detection accuracy of measurements. In this study, a methodology of real-time separation of aerosolized Staphylococcus epidermidis (S. epidermidis) and polystyrene latex (PSL) particles...

To assess indoor bioaerosols, a virtual impactor having 1 µm cutoff diameter was designed, fabricated, and evaluated with computational fluid dynamics simulation and also with laboratory test using polystyrene latex particles. Two other cutoff diameters of 635 nm and 1.5 µm were obtained by changing the inlet flow rate and the ratio of minor channe...

This paper reports on the full realization of an ultrafine particle monitoring system, including a MEMS-based particle processing chip and signal processing circuits. Unlike a conventional liquid-based microfluidic chip, the proposed particle processing chip handles a mixture of gas and particles. The proposed particle monitoring system is suitable...