• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.3
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• pp.41-52
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• 2014

In this study, to estimate the biodegradability of sewage discharged intermittently, field scale sampling and analysis was conducted and the results were obtained as follows. According to results of the biodegradability of sewage discharged intermittently, average concentration of TCODcr is 325.5mg/L and ratio of TCOD fraction resulted 100%. Also, average concentration of SCODcr resulted 135.9mg/L and ratio of TCOD fraction resulted 41.8%. Average concentration of Ss showed 74.1mg/L and ratio of TCOD fraction resulted 22.8%. Average concentration of $S_I$ was analyzed to be 61.8mg/L and ratio of TCOD fraction was calculated to 19.0%. Xs which is particulate matter was analyzed to show 27.8mg/L and ratio of TCOD fraction also showed 8.5%. Average concentration of $X_H$ is 103.4mg/L and ratio of TCOD fraction resulted 31.8%. Inert particulate matter showed that average concentration of $X_I$ is 58.5mg/L and ratio of TCOD fraction resulted 18.0%. Accordingly, dissolved biodegradable organic matter showed the ratio of 41.8%, and readily biodegradable matter among this showed 22.8%. Thus intermittent inflow is expected to have less effect with regards equalization by organic loading rate of influent.

• Journal of ILASS-Korea
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• v.14 no.1
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• pp.15-19
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• 2009

This paper is to investigated the analysis of performance characteristics of diesel oxidation catalyst (DOC) for diesel vehicle with 2.5L piston displacement. The performance evaluation test of DOC applied to test diesel vehicle was carried out for four kinds of DOCs manufactured from different company. The testing DOCs were randomly selected from the retrofit vehicle and then standard test vehicle that was representative for the application group was equipped with DOC for the test. In this verification test, the reduction rate of particulate matter (P.M.) and the deviation of the performance of the DOC were examined through CVS-75 mode of the standard vehicle and SOF reduction rate of specific DOC was investigated. It was found that some DOCs failed to pass the criteria of the P.M. reduction rate because of the reason seen catalyst aging even if they were same devices. In the result of SOF analysis, the specific DOC showed more PM reduction than SOF of PM. reduction exceptionally.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.164-170
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• 1996

Among after treatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now being studied actively. In this study, an experiment was conducted to analyze the effects on factors of oxidaton characteristics and conversion efficiency of DOC. We tested to estimate change of engine performance whether a 11,000cc diesel engine equipps with DOC or not. We conducted test to estimate the reduction efficiency of exhaust gas in P-5 mode, in D-13 mode of heavy duty diesel regulation mode and in somoke opacity mode for two samples and also we conducted test to analyze the effects about both exhaust gas velocities 1,100rpm and 2,200rpm

• Journal of Korean Society of Environmental Engineers
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• v.34 no.2
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• pp.97-102
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• 2012

The purpose of this study is to clarify the origin and the variation of essential fatty acid (FA) and food sources of Stenopsyche marmorata at downstream region of Dam. As a result, the water particulate organic matter (POM) is mainly derived from diatom, green algae and bacteria. Moreover, the main food sources of S. marmorata mainly used diatom, green algae and bacteria. ${\omega}3$ essential FA of S. marmorata was higher than ${\omega}6$, and showed about 7 for essential FA ratio.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.2
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• pp.144-150
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• 2016

In southwestern East Sea, we investigated the spatio-temporal distribution characteristics of particulate organic carbon (POC) and nitrogen (PON) in September 2011 (summer), January (winter) and May 2012 (spring). Although cold waters known as the origin upwelling in the surface layer of September were not observed, this periods showed high primary productivity because of high concentrations of chlorophyll, low percentage of non-autotrophic particulate fraction among POC calculated by POC/Chl-a ratio (27%) and low POC/PON ratio (6.2), which means active amino acid and protein synthesis, However, May, 2012 showed low primary productivity because of high percentage of non-autotrophic particulate fractions among POC (66%) and high POC/PON ratio (8.1), Although spring bloom and high primary productivity has been reported in the East Sea, high percentage of non-autotrophic particulate fractions in POC, observed in the East sea during the post 2012 spring, is suggested to be due to the increase of phaeo-pigment during post spring bloom. Thus, composition of particulate organic matter may have sensitively changed by marine environmental factors in spite of same season.

• Animal cells and systems
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• v.15 no.3
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• pp.235-241
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• 2011

To examine variation in trophic pathways and the characteristics of food webs from organic matters to aquatic insects, we used stable isotopes to study an intermittent stream system of the Inukami River, Japan. The aquatic insects, including Glossosoma spp., Chironominae spp., Stenelmis spp., Rhyacophilla nigrocephala, and Hexatoma spp., were characterized by different feeding strategies. The ${\delta}^{13}C$ values for these species indicated that Glossosoma spp. graze upon periphyton; Chironominae and Stenelmis spp. mainly feed on benthic particulate organic matter, and R. nigrocephala and Hexatoma spp., which were identified as predators, feed upon Glossosoma, Stenelmis, and/or Chironominae spp. This suggests that the trophic position of consumers at each station may be determined by the trophic position of basal food sources in situ. For trophic pathways, the ${\delta}^{13}C$ values for both organic matter and aquatic insects tended to gradually decrease, whilst the ${\delta}^{15}N$ values increased from the upper reach to the lower reaches, relative to the physicochemical and geographical conditions. These parameters indirectly influence the flow of energy from organic matter to consumers within food web in an intermittent stream system.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.5
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• pp.567-576
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• 1996

Air pollution has been recognized for many years as a factor which heightens the risk of cancer. Extractable polycyclic organic matters in air particulates have been recognized as to have carcinogenic effects. This study examined the health risks posed by organic substances of air particulates in Seoul based on methodelogies that have been developed for conducting risk posed by organic substances of sir particulates in Seoul based on methodologies that have been developed for conducting risk assessment of complex -chemical-mixture. The data used in this study was obtained from air samples collected in a heavy traffic area of Seoul (Shinchon) from 1986 to 1994. The mean concentration of total supended pariculates was 158.0.mu.g/m/msup 3/, 5% of which is consisted of organic matter. The excess cancer risk from benzo(a)pyrene (BaP) was estimated to be 3.48.times.10$^{-6}$ by applying BaP unit risk estimates to the mean concentration. 8.74ng/m BaP equivalents of potency method was 1.0.times.10$^{-3}$ . The calculated risk from EOM were comparably higher than that from benzo(a)pyrene and exceeded the acceptable risk level.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.51-56
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• 2016

Particulate matter (PM) in the atmosphere has wide-ranging health, environmental, and climate effects, many of which are attributed to fine-mode secondary organic aerosols. PM concentrations are significantly enhanced by primary particle emissions from traffic sources. Recently, in order to reduce $CO_2$ and increase fuel economy, gasoline direct injected (GDI) engine technology is increasingly used in vehicle manufactures. The popularization of GDI technique has resulted in increasing of concerns on environmental protection. In order to better understand variations in chemical composition of particulate matter from emissions of GDI vehicle versus a port fuel injected (PFI) vehicle, a high time resolution chemical composition of PM emissions from GDI and PFI vehicles was measured at facility of Transport Pollution Research Center (TPRC), National Institute of Environmental Research (NIER), Korea. Continuous measurements of inorganic and organic species in PM were conducted using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The HR-ToF-AMS provides insight into non-refractory PM composition, including concentrations of nitrate, sulfate, hydrocarbon-like and oxygenated organic aerosol, and organic mass with 20 sec time resolution. Many cases of PM emissions during the study were dominated by organic and nitrate aerosol. An overview of observed PM characteristics will be provided along with an analysis of comparison of GDI vehicle versus PFI vehicle in PM emission rates and oxidation states.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.21-26
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• 2008

The in situ incubation experiment was carried out using $^{13}C$ tracer to determine primary productivity and fatty acid production rate in the shallow, eutrophic Shingu reservoir on 4th July. Particulate organic matter (POM) accounted for 76% in suspended particulate matter (SPM), and average concentration of chlorophyll-${\alpha}$ was $89{\mu}g\;L^{-1}$ in the euphotic layer. Total amount of chlorophyll-${\alpha}$ (Chl-${alpha}$), primary productivity and Chl-${alpha}$ specific productivity in euphotic layer were 112 mg Chl-${alpha}m^{-2}$, 3.53 g C $m^{-2}\;d^{-1}$, 32mg C mg Chl-${\alpha}^{-1}\;d^{-1}$, respectively. The fatty acid composition in newly produced organic matter and suspended organic matter didn't show any significant difference, demonstrating that autochthonous organic matter should be a major source of POM pool. In addition, the fatty acids of bacterial origin were increased through extracellular release of newly photosynthesized DOC, and closely coupled with bacterial assimilation. This result suggests that organic carbon should be actively cycled through the microbial loop in Shingu reservoir in summer.

• Environmental Engineering Research
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• v.23 no.2
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• pp.143-149
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• 2018

Air quality conditions and pollution status have been evaluated in the industrial area between Sharjah and Ajman border in UAE. Daily concentrations of $O_3$, CO, $NO_2$, $SO_2$, $PM_{2.5}$, $PM_{10}$, Total Volatile Organic Compounds (TVOC) and Total Suspended Particulate (TSP) have been monitored from Sept. 2015 to April 2016. The monthly average concentrations of $O_3$, CO, $NO_2$, $SO_2$, TVOC were within the UAE ambient air quality standards during the survey period. However, $PM_{10}$ and TSP levels exceeded the recommended limits in Sept. 2015, Oct. 2015 and March 2016. Temporal variations in air quality parameters showed highest levels in March 2016 for $PM_{2.5}$, $PM_{10}$, $NO_2$, TVOC and TSP, whereas $O_3$, $SO_2$ and CO showed relatively low values in this month. $PM_{2.5}$ levels in ambient air were above the EPA guideline of $35{\mu}g/m^3$ in all months. $PM_{2.5}$ was the critical ambient air pollutant with Index for Pollutant ($I_p$) values varying from 103-209, indicating Air Quality Index categories of unhealthy for sensitive groups (62.5%) to unhealthy (25%) to very unhealthy (12.5%). The $I_p$ average values of $PM_{2.5}$ decreased from Sept. 2015 to reach lowest value in Dec. 2015 before increasing gradually, peaking in March 2016. These results suggest the potential health risks associated with $PM_{2.5}$ is low in winter, where the prevailing meteorological conditions of lower temperatures, higher humidity, higher wind speed reduced particulate matter. The results revealed the industrial area is impacted by anthropogenic and natural sources of particulate matter.