• Journal of Korean Society for Atmospheric Environment
• /
• v.33 no.3
• /
• pp.205-216
• /
• 2017

Carbonaceous aerosols such as the equivalent black carbon (eBC), the elemental carbon (EC) and the organic carbon (OC) were monitored at the Seoul Olympic Park site ($37.521^{\circ}N$, $127.124^{\circ}E$) during the KORUS-AQ 2016 campaign using a Multi Angle Absorption Photometer (MAAP) and an OCEC Analyzer. Averaged mass concentrations of eBC, EC and OC were presented as $2.46{\pm}1.52{\mu}g/m^3$, $1.01{\pm}0.60{\mu}g/m^3$ and $4.85{\pm}2.60{\mu}g/m^3$, respectively. OC/EC ratio and mass absorption cross-section (MAC) of light absorbing aerosols were calculated as 2.32 and $14.8m^2/g$, respectively. Diesel OC concentrations were estimated from a source profile of diesel vehicles as well. eBC mass concentrations measured from May $26^{th}$ to May $27^{th}$, 2016 showed 40% higher than averaged eBC mass concentrations during campaign period. $PM_{2.5}$ concentrations measured in this period were also higher than average $PM_{2.5}$ concentrations. High eBC concentrations were observed from May $29^{th}$ to May $31^{st}$, 2016 and from June $9^{th}$ to June $11^{th}$, 2016, possibly due to morning rush hour and the effect of temperature inversion at night. Diurnal variations of eBC, EC and Diesel OC showed a typical pattern of metropolitan area. In the weekend, however, diurnal variations of eBC, EC and Diesel OC mass concentrations were different from those measured in the weekday. It is expected that this study can help to understand the relationship between carbonaceous aerosols in a metropolitan area.

• Analytical Science and Technology
• /
• v.14 no.5
• /
• pp.422-431
• /
• 2001

One pulp manufacture facility was selected as surveying facility to examine the discharged amount and generation mechanism of dioxins excepts for bleaching stage wastewater. In recovery and finishing process, 2,3,7,8-TCDF, OCDD and OCDF were mainly detected, and the ratio of PCDDs and 1,2,3,4,7,8-HxCDD as the concentration of 2,3,7,8-substitute isomer were discharged which is known as the typical emission pattern of pulp and paper manufacture facility, and the 1,2,3,7,8-PeCDD and 1,2,3,4,7,8-HxCDD were discharged more than 90% in toxic equivalent concentration. Also, the OCDD and 2,3,7,8-TCDF for 2,3,7,8-isomer concentration, and 1,2,3,7,8-PeCDD and 2,3,7,8-TCDF as toxic equivalent concentration were discharged in effluent. The detected PCDDs/PCDFs concentration were surveyed 0.2266 ng-TEQ/L for influent and 0.0377 ng-TEQ/L for effluent.

• Journal of the Economic Geographical Society of Korea
• /
• v.13 no.3
• /
• pp.398-415
• /
• 2010

The purpose of this paper is to grasp levels of cost burden in pollution treatment by measuring efficiencies and shadow prices by pollutants in Korean cities. The efficiencies and shadow prices of pollutants will be compared for cities divided by Seoul metropolitan area and non-Seoul metropolitan area. Annual shadow prices of NOx, SOx, and PM10 emissions in the cities of Seoul metropolitan area are 0.846, 0.318, 0.816, respectively for 1999-2005. The annual shadow prices in the cities of Non-Seoul metropolitan area are 0.848, 0.272, and 0.789, respectively over the same periods. The shadow prices of SOx showed similar levels between two areas but those of NOx and PM10 of cities in Seoul metropolitan area were higher. NOx emission quantities of both areas have similar increasing patterns because the NOx has mainly increased with augmentation of transportation regardless of Seoul metropolitan and non-Seoul metropolitan areas. It seems that the reason the shadow prices of two pollutants for the cities of Seoul metropolitan area are higher, is because environmental regulation is stronger in the cities of Seoul metropolitan area, the cities of Seoul metropolitan relatively show higher quantities of pollution reduction under given desirable outputs, and generally have industrial sectors with small pollution emission. In the future we need to reduce pollutants in the various respects such as adjustment of overall industry structure, energy consumption pattern, and reviews of arrangement of living space for the cities located on the downward-sloping segment of production frontier.

• Molecular & Cellular Toxicology
• /
• v.3 no.3
• /
• pp.198-207
• /
• 2007

[ $^{18}F$ ]-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan has been found to reflect tumor aggressiveness and prognosis in various types of cancer. In this study, the gene expression profiles of glial tumors were evaluated to determine whether glial tumors with high $^{18}F$-FDG uptake have more aggressive biological potential than with low uptake. Surgical specimens were obtained from the 12 patients with glial tumors (4 males and 8 females, age range 42-68 years). The tumor samples were divided into two groups based on the $^{18}F$-FDG uptake PET scan findings: high $^{18}F$-FDG uptake (n=4) and low $^{18}F$-FDG uptake (n=8). The pathological tumor grade was closely correlated with the $^{18}F$-FDG uptake pattern: Glial tumors with high $^{18}F$-FDG uptake were pathologically Edmondson-Steiner grade III, while those with low uptake were grade II. The total RNA was extracted from the frozen tissues of all glial tumors (n=12), and adjacent non-cancerous tissue (n=3). The gene expression profiles were evaluated using cDNA microarray. The glial tumors with high $^{18}F$-FDG uptake showed increase expression of 15 genes compared to those with low uptake (P<0.005). Nine genes were down-regulated. Gene expression is closely related to cell survival, cell-to-cell adhesion or cell spreading; therefore, glial tumors with high $^{18}F$-FDG uptake appear to have more aggressive biological properties than those with low uptake.

• Ocean and Polar Research
• /
• v.29 no.2
• /
• pp.87-99
• /
• 2007

This study was conducted to understand the source and behavior of organic matter using the fluorescent technique (excitation-emission matrix) as a part of environmental monitoring program in the Korea manganese nodule mining site in the Northeastern Pacific Ocean. Water samples were collected at $0^{\circ},\;6^{\circ}N$, and $10.5^{\circ}N$ along $131.5^{\circ}W$ in August 2005. The concentration of total organic carbon (TOC) ranged from 58.01 to $171.93\;{\mu}M-C$. The vertical distribution of TOC was characterized as higher in the surface layer and decreased with depth. At $6^{\circ}N$, depth-integrated (from surface to 200 m depth) TOC was $337.1\;gC/m^2$, which was 1.4 times higher value than other stations. The exponential decay curve fit of vertical profile of TOC indicated that 59% of organic carbon produced by primary production in the surface layer could be decomposed by bacteria in the water column. Dissolved organic matter is generally classified into two distinctive groups based on their fluorescence characteristics using three-dimensional excitation/emission (Ex/Em) fluorescence mapping technique. One is known as biomacromolecule (BM; protein-like substance; showing max. at Ex 280/Em 330), mainly originated from biological metabolism. The other is geomacromolecule (GM; humic-like substance; showing max. at Ex 330/Em 430), mainly originated from microbial degradation processes. The concentration of BM and GM was from 0.42 to 7.29 TU (tryptophan unit) and from 0.06 to 1.81 QSU (quinine sulfate unit), respectively. The vertical distribution of BM was similar to that of TOC as high in the surface and decreased with depth. However, the vertical distribution of GM showed the reverse pattern of that of BM. From these results, it appeared that BM occupied a major part of TOC and was rapidly consumed by bacteria in the surface layer. GM was mainly transformed from BM by microbial processes and was a dominant component of TOC in the deep-sea layer.

• Progress in Medical Physics
• /
• v.12 no.1
• /
• pp.1-8
• /
• 2001

Diamond thin films were synthesized by a chemical vapor deposition (CVD). Raman spectrum showed the diamond line at 1332 $cm^{-1}$ / and x-ray diffraction pattern exhibited a strong (111) peak of diamond. The scanning electron microscopy analysis showed that the CVD diamond thin film was grown to be unepitaxial crystallites with pyramidal hillocks. A wavelength-resolved thermoluminescence (TL) of the CVD diamond thin film irradiated with X-rays showed one peak at 430 nm around 560 K. The glow curve of the CVD diamond thin film produced one dominant 560-K peak that was caused by first-order kinetics. Its activation energy and the escape frequency were calculated to be 0.92 ～ 1.05 eV and 1.34 $\times$ 10$^{7}$ sec$^{-1}$ , respectively. The emission spectrum at 560 K was split into 1.63-eV, 2.60-eV, and 3.07-eV emission bands which is known to be attribute to silicon-vacancy center, A center, and H3 center, respectively.

• Journal of the Korea Concrete Institute
• /
• v.21 no.5
• /
• pp.589-597
• /
• 2009

High Performance Fiber-reinforced Cement Composite (HPFRCC) shows the multiple crack and damage tolerance capacity due to the interfacial bonding of the fibers to the cement matrix. For practical application, it is needed to investigate the fractural behavior of HPFRCC and understand the micro-mechanism of cement matrix with reinforcing fiber. This study is devoted to the investigation of the AE signals in HPFRCC under monotonic and cyclic uniaxial compressive loading, and total four series were tested. The major experimental parameters include the type and volume fraction of fiber (PE, PVA, SC), the hybrid type and loading pattern. The test results showed that the damage progress by compressive behavior of the HPFRCC is a characteristic for the hybrid fiber type and volume fraction. It is found from acoustic emission (AE) parameter value, that the second and third compressive load cycles resulted in successive decrease of the amplitude as compared with the first compressive load cycle. Also, the AE Kaiser effect existed in HPFRCC specimens up to 80% of its ultimate strength. These observations suggested that the AE Kaiser effect has good potential to be used as a new tool to monitor the loading history of HPFRCC.

• Korean Journal of Ecology and Environment
• /
• v.46 no.3
• /
• pp.409-418
• /
• 2013

Global warming due to climate change is a problem facing the entire world. Several factors, such as $CO_2O$ concentration, level of warming, soil temperature, precipitation, water content of soil and denitrification by denitrifying bacteria influence the emission of nitrous oxide ($N_2O$) from soil. In this study, we investigated nitrous oxide emissions from the soil of two wetlands, Jilmoineup in Mt. Odae and Moojechineup in Mt. Jungjok, according to temperature change. Soil collected in Jilmoineup in July showed increasing $N_2O$ emissions as temperature increases, but did not show any significant differences at $10^{\circ}C$ (p<0.05). Soil of $15^{\circ}C$ and $20^{\circ}C$ showed increasing pattern of $N_2O$ emissions until 24 h. After that, however, there was no difference in temperature. Overall, $N_2O$ emissions showed significant differences according to temperature (p<0.05). Soil collected from Moojechineup in July showed increasing $N_2O$ emissions according to temperature increase, but did not show any significant differences at $10^{\circ}C$ (p<0.05) as was the case for Jilmoineup soil. On the other hand, two wetland soils showed a slight increase of $N_2O$ emissions by additional nitrogen supply, but did not show any significant differences in the presence of nitrogen or between nitrogen sources. In conclusion, increasing temperature the wetland soil increased the emission of $N_2O$, which is a known greenhouse gas. In order to more clearly identify $N_2O$ emissions, various subsequent studies such as the influence and correlation of several factors are required.

• Journal of Korean Society of Transportation
• /
• v.34 no.2
• /
• pp.107-122
• /
• 2016

This study aims to develop a framework to estimate mobile source emissions with the macroscopic travel demand model including enhanced estimates of intra-zonal travel emissions using Space Syntax analysis. It is acknowledged that "the land-use and transportation interaction model explains the influence of urban structure on accessibility and mobility pattern". Based upon this theory, the estimation model of intra-zonal travel emissions is presented with the models of total travel distance, total travel demand, and average travel speed of intra-zonal trips. Thess statistical models include several spatial indices derived from the Space Syntax analysis. It explains that urban spatial structure is a critical factor for intra-zonal travel emissions, which is lower in compact zone with smaller portion of land area, lower sprawl indicator, and more grid-type of road network. Also the suggested framework is applied in the evaluation of the effectiveness of bicycle lane project in Suwon, Korea. The estimated emissions including intra-zonal travel is as double as the results only with inter-zonal demands, which shows better performance of the suggested framework for more realistic outcomes. This framework is applicable to the estimation of mobile source emissions in nation-wide and the assessment of transportation-environment policies in regional level.

• Journal of Animal Science and Technology
• /
• v.53 no.5
• /
• pp.475-480
• /
• 2011

This study was conducted to investigate the effects of different feeding level of TDN (Total Digestible Nutrients) on the generation of main greenhouse gases such as carbon dioxide and methane in Hanwoo cows. The diet TDN (kg) adjusted to achieve ADG of 0 g/day (Control), 200 g/day (T1), and 400 g/day (T2) of the maintenance level TMR (Total Mixed Ration) delivered twice a day at 08:30 and 17:30. Cow are housed in a respiration chamber and the environmental temperature was maintained at $20^{\circ}C$. The gases were measured for 24 hours using the multi-detector instrument Mamos-300. The analyzed methane emissions of T1 and T2 were 33.5% and 69.6% higher than control, respectively, and the carbon dioxide emissions were 21.1% and 40.6% higher than control. Also, the hourly pattern of carbon dioxide and methane production were showed very similar emission. Gas production showed peak after 1 hour of feeding and this gap was wider in the afternoon than in the morning hours. It is clearly conducted that $CO_2$ and $CH_4$ emissions were different by limited intake levels of feed.