Air change rates (ACRs) and interzonal flows are key determinants of indoor air quality (IAQ) and building energy use. This paper characterizes ACRs and interzonal flows in 126 houses, and evaluates effects of these parameters on IAQ. ACRs measured using weeklong tracer measurements in several seasons averaged 0.73 ± 0.76 h(-1) (median = 0.57 h(-1), n = 263) in the general living area, and much...

1 Department of Microbial Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, South Korea. 2 Department of Textile Engineering, Konkuk University, 1 Hwayang-dong, Gwangjing-gu, Seoul, South Korea. 3 Water Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul, South Korea. 4 Department of Biological sciences, Konkuk University, 1 Hwayang-dong, Gwangjin-gu...

The fractional filtration efficiency for particles ranging from 5 nm to 100 nm was estimated based on previous publications. The downstream concentration and size distribution was calculated for each of four outdoor aerosols representing both urban and rural conditions. When interpreting data expressed as the total number concentration (dp>5 nm), the studied F7filter (corresponding roughly to M...

Low-energy X and γ radiations (for example of 210Pb: Eγ = 46.5 keV) are effectively self-absorbed even in thin environmental samples, including air filters with captured dust or contaminated soil, as well as in bottom sediment matrixes with limited quantities of the samples. In this paper, a simple method for the direct analysis of 210Pb (T1/2 = 22.3 years) by gamma-ray spectrometry in environm...

There has been consistent interest among speech signal processing researchers in the accurate estimation of the fundamental frequency (F(0)) of speech signals. This study examines ten F(0) estimation algorithms (some well-established and some proposed more recently) to determine which of these algorithms is, on average, better able to estimate F(0) in the sustained vowel /a/. Moreover, a robust...

Aerosols composed of viable particles of a uniform size were produced with a commercial spinning-disc generator from aqueous suspensions of Bacillus subtilis var. niger spores containing various amounts of an inert material, dextran, to regulate aerosol particle size. Aerosols composed of single naked spores having an equivalent spherical diameter of 0.87 mum were produced from spore suspension...

In a historic building with inadequate or no air conditioning or where it is not possible to install modern systems fitted with air filters, humidification, and controls, it is possible to mitigate the effects of temperature and humidity extremes on a building and its contents by controlling air-flow. When used in conjunction with mechanical air conditioning, this method can also save a little ...

UNLABELLED A study was carried out to investigate the feasibility of achieving ultra low respirable suspended particulates (RSP) in commercial offices without major modification of existing ventilation systems by enhancing the particulates removal efficiency of existing central ventilation systems. Four types of filters which include pre-filters, cartridge filters, bag filters and high efficien...

A broadband microstrip bandpass filter (BPF) with compact size, sharp skirt and wide upperstopband performance is proposed using the triple-mode stub-loaded resonator. The resonator can generate one odd mode and two even modes in the desired passband. Due to the main path signal counteraction, two transmission zeros Tz1, Tz2 can be created near the passband edge to achieve sharp skirt. Two tran...