Emission Rate of Particulate Matter and Its Removal Efficiency by Precipitators in Under-Fired Charbroiling Restaurants

Lee, Jun-Bok,Kim, Ki-Hyun,Kim, Heung-Joo,Cho, Seog-Ju,Jung, Kweon,Kim, Shin-Do TheScientificWorldJOURNAL 2011 The Scientific World Journal Vol.11 No.-

<P>In order to explore the potent role of meat cooking processes as the emission sources of particulate matter (PM), emission rates and the associated removal efficiency by precipitators were estimated based on the on-site measurements made at five under-fired charbroiling (UFC) restaurants. The emission patterns of PM for these five restaurants were compared after having been sorted into the main meat types used for cooking: beef (B), chicken (C), intestines (I), and pork (P: two sites). The mass concentrations (μg m<SUP>-3</SUP>) of three PM fractions (PM<SUB>2.5</SUB>/PM<SUB>10</SUB>/TSP) measured from these restaurants were 15,510/15,701/17,175 (C); 8,525/10,760/12,676 (B); 11,027/13,249/13,488 (P); and 22,409/22,412/22,414 (I). Emission factors (g kg<SUP>-1</SUP>) for those PM fractions were also estimated as 3.23/4.08/4.80 (B), 3.07/3.82/3.87 (P), 8.12/8.22/8.99 (C), and 6.59/6.59/6.59 (I). If the annual emission rate of PM<SUB>10</SUB> is extrapolated by combining its emission factor, population, activity factor, etc., it is estimated as 500 ton year<SUP>-1</SUP>, which corresponds to 2.4% of the PM<SUB>10</SUB> budget in Seoul, Korea. Removal efficiencies of PM<SUB>10</SUB> via precipitators, such as an electrostatic precipitator (ESP), bag filter (BF), and the combination system (ESP + catalyst), installed in those UFC restaurants ranged between 54.76 and 98.98%. The removal efficiency of PM by this control system was the least effective for particles with <0.4 μm, although those in the range of 0.4–10 μm were the most effective.</P>

Transmembrane Domain—Dependent Functional Oligomerization of Syndecans

Yi, Jae Youn,Han, Innoc,Oh, Eok-Soo TheScientificWorldJOURNAL 2006 The Scientific World Journal Vol.6 No.-

<P>Cell surface adhesion receptors of the syndecan family initiate intracellular events through clustering of receptors. This crucial clustering occurs through receptor dimerization or oligomerization, which is mediated by receptor transmembrane domains. However, the exact role of the transmembrane domain during receptor activation is not fully understood. Researchers have not yet determined whether the transmembrane domain functions solely in the physical aspects of receptor clustering, or whether the domain has additional functional roles. Here we review recent advances in understanding the functionality of transmembrane domain—dependent oligomerization of syndecan cell adhesion receptor.</P>

Determination of Hazardous VOCs and Nicotine Released from Mainstream Smoke by the Combination of the SPME and GC-MS Methods

Pandey, Sudhir Kumar,Kim, Ki-Hyun TheScientificWorldJOURNAL 2010 The Scientific World Journal Vol.10 No.-

<P>In this study, the contents of nicotine and volatile organic compounds (VOCs) in mainstream smoke (MSS) were analyzed using samples of four cigarette types consisting of two common brands (R and E) with full (F) and light (L) flavor, coded with R-F, R-L, E-F, and E-L. These cigarettes were also analyzed after removing the filter portions with the assignment of a new sample code of (N) as the third letter (e.g., R-L-N). A total of 44 VOCs (including nicotine) were quantified by the combination of the SPME and GC-MS methods. Out of the 44 VOCs, 10 were identified as hazardous air pollutants listed by the U.S. EPA, while their concentrations exceeded the reference exposure limits set by various agencies. A clear distinction was apparent in the concentration levels of VOCs between different brands or between full and light flavors. Nicotine concentrations varied greatly between different cigarettes types of the R brand, whereas such changes were insignificant in the counterpart E brand. This thus suggests that light-flavor cigarettes do not necessarily guarantee low doses of carcinogens (and tar) than regular cigarettes, as their differences can be balanced by the inhaling behavior of the smoker.</P>

Concentrations of TSP-Bound Metals in Four Urban Residential Locations in Seoul, Korea

Nguyen, Hang Thi,Park, Chan Goo,Kim, Jin-A,Lee, Je-Seung,Lee, Jin-Hong,Kim, Ki-Hyun TheScientificWorldJOURNAL 2010 The Scientific World Journal Vol.10 No.-

<P>Concentrations of 17 trace metals bound in total suspended particulate (TSP) were measured at four urban residential locations (Jong Ro [JR], Gwang Jin [GJ], Gang Seo [GS], and Yang Jae [YJ]) in Seoul, Korea from February to July 2009. The maximum concentrations of metals were recorded by Fe in the range of 2599 (JR) to 2914 ng m<SUP>-3</SUP> (GJ), while the least values were observed from Ag or Co with a few ng m<SUP>-3</SUP>. The relative ordering of the mean concentration (ng m<SUP>-3</SUP>) at these sites is generally found on the order of Fe > Zn > Ba > Mn > Pb > Cu > B > Cr > Ni > Sr >V > As > Li > Cd > Mo > Co > Ag or with a few exceptions (e.g., a reversal between Ba and Mn or between Ni and Sr). Calculation of the enrichment factor suggests the significant role of man-made processes on such metals as Cd, Zn, and Pb. Inspection of the temporal patterns indicates the peak occurrence of most metals during the spring season due in part to the Asian Dust (AD) event. However, according to the factor analysis, sources of these metals were dominated by both resuspended soil/road dust and the combustion of fossil fuels. The overall results of our study suggest that the interaction between the environmental conditions and roadside traffic activities are paramount in explaining the metal pollution in these urban residential areas.</P>

Sorptive Removal of Odorous Carbonyl Gases by Water

Kabir, Ehsanul,Kim, Ki-Hyun TheScientificWorldJOURNAL 2010 The Scientific World Journal Vol.10 No.-

<P>In this study, the removal capacity of deionized water was investigated against five gaseous carbonyl compounds (i.e., acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and isovaleraldehyde) by means of the gas stripping method. To determine the trapping behavior of these odorants by water, gaseous working standards prepared at three different concentration levels (i.e., for acetaldehyde around 300, 500, and 1,000 ppb) were forced through pure water contained in an impinger at room temperature. The removal efficiency of the target compounds was inspected in terms of two major variables: (1) concentration levels of gaseous standard and (2) impinger water volume (20, 50, 100, and 150 mL). Although the extent of removal was affected fairly sensitively by changes in water volume, this was not the case for standard concentration level changes. Considering the efficiency of sorption media, gas stripping with aqueous solution can be employed as an effective tool for the removal of carbonyl odorants.</P>

Some Insights into Analytical Bias Involved in the Application of Grab Sampling for Volatile Organic Compounds: A Case Study against Used Tedlar Bags

Ghosh, Samik,Kim, Ki-Hyun,Sohn, Jong Ryeul TheScientificWorldJOURNAL 2011 The Scientific World Journal Vol.11 No.-

<P>In this study, we have examined the patterns of VOCs released from used Tedlar bags that were once used for the collection under strong source activities. In this way, we attempted to account for the possible bias associated with the repetitive use of Tedlar bags. To this end, we selected the bags that were never heated. All of these target bags were used in ambient temperature (typically at or below 30°C). These bags were also dealt carefully to avoid any mechanical abrasion. This study will provide the essential information regarding the interaction between VOCs and Tedlar bag materials as a potential source of bias in bag sampling approaches.</P>

Comparing the Heterogeneity of Copper-Binding Characteristics for Two Different-Sized Soil Humic Acid Fractions Using Fluorescence Quenching Combined with 2D-COS

Hur, Jin,Lee, Bo-Mi TheScientificWorldJOURNAL 2011 The Scientific World Journal Vol.11 No.-

<P>Heterogeneous distributions of copper-binding characteristics were compared for two ultrafiltered size fractions of a soil HA using fluorescence quenching combined with two-dimensional correlation spectroscopy (2D-COS). The apparent shapes of the original synchronous fluorescence spectra and the extent of the fluorescence quenching upon the addition of copper were similar for the two fractions. The stability constants calculated at their highest peaks were not significantly different. However, the 2D-COS results revealed that the fluorescence quenching behaviors were strongly affected by the associated wavelengths and the fraction's size. The spectral change preferentially occurred in the wavelength order of 467 nm → 451 nm → 357 nm for the 1–10 K fraction and of 376 nm → 464 nm for the >100 K fraction. The extent of the binding affinities exactly followed the sequential orders interpreted from the 2D-COS, and they exhibited the distinctive ranges of the logarithmic values from 5.86 to 4.91 and from 6.48 to 5.95 for the 1–10 K and the >100 K fractions, respectively. Our studies demonstrated that fluorescence quenching combined with 2D-COS could be successfully utilized to give insight into the chemical heterogeneity associated with metal-binding sites within the relatively homogeneous HA size fractions.</P>

Emerging Measurement Techniques for Airborne Pollutants

Kim, Ki-Hyun,Brown, Richard J. C. TheScientificWorldJOURNAL 2011 The Scientific World Journal Vol.11 No.-

Emission Rates of Volatile Organic Compounds Released from Newly Produced Household Furniture Products Using a Large-Scale Chamber Testing Method

Ho, Duy Xuan,Kim, Ki-Hyun,Ryeul Sohn, Jong,Hee Oh, Youn,Ahn, Ji-Won TheScientificWorldJOURNAL 2011 The Scientific World Journal Vol.11 No.-

<P>The emission rates of volatile organic compounds (VOCs) were measured to investigate the emission characteristics of five types of common furniture products using a 5 m<SUP>3</SUP> size chamber at 25°C and 50% humidity. The results indicated that toluene and <I><I>α</I></I>-pinene are the most dominant components. The emission rates of individual components decreased constantly through time, approaching the equilibrium emission level. The relative ordering of their emission rates, if assessed in terms of total VOC (TVOC), can be arranged as follows: dining table > sofa > desk chair > bedside table > cabinet. If the emission rates of VOCs are examined between different chemical groups, they can also be arranged in the following order: aromatic (AR) > terpenes (TER) > carbonyl (CBN) > others > paraffin (PR) > olefin (HOL) > halogenated paraffin (HPR). In addition, if emission strengths are compared between coated and uncoated furniture, there is no significant difference in terms of emission magnitude. Our results indicate that the emission characteristics of VOC are greatly distinguished between different furniture products in terms of relative dominance between different chemicals.</P>

Prediction on the Seasonal Behavior of Hydrogen Sulfide Using a Neural Network Model

Kim, Byungwhan,Lee, Joogong,Jang, Jungyoung,Han, Dongil,Kim, Ki-Hyun TheScientificWorldJOURNAL 2011 The Scientific World Journal Vol.11 No.-

<P>Models to predict seasonal hydrogen sulfide (H<SUB>2</SUB>S) concentrations were constructed using neural networks. To this end, two types of generalized regression neural networks and radial basis function networks are considered and optimized. The input data for H<SUB>2</SUB>S were collected from August 2005 to Fall 2006 from a huge industrial complex located in Ansan City, Korea. Three types of seasonal groupings were prepared and one optimized model is built for each dataset. These optimized models were then used for the analysis of the sensitivity and main effect of the parameters. H<SUB>2</SUB>S was noted to be very sensitive to rainfall during the spring and summer. In the autumn, its sensitivity showed a strong dependency on wind speed and pressure. Pressure was identified as the most influential parameter during the spring and summer. In the autumn, relative humidity overwhelmingly affected H<SUB>2</SUB>S. It was noted that H<SUB>2</SUB>S maintained an inverse relationship with a number of parameters (e.g., radiation, wind speed, or dew-point temperature). In contrast, it exhibited a declining trend with a decrease in pressure. An increase in radiation was likely to decrease during spring and summer, but the opposite trend was predicted for the autumn. The overall results of this study thus suggest that the behavior of H<SUB>2</SUB>S can be accounted for by a diverse combination of meteorological parameters across seasons.</P>