Cathodic Functional Layer via Sputtering and Atomic Layer Deposition for Thin-Film Solid Oxide Fuel Cells

이재윤(Jaeyoon Lee),이상혁(Sanghyeok Lee),김현택(Hyeontaek Kim),박용찬(Yongchan Park),이근진(Geunjin Lee),이창헌(Changheon Lee),최성규(Sunggyu Choi),홍순욱(Soonwook Hong) Korean Society for Precision Engineering 2022 한국정밀공학회지 Vol.39 No.2

안정동위원소 기반 HNS 생물 축적성 평가

이동헌(Dong-Hun Lee),이성규(Sunggyu Lee),임동훈(Dong-Hoon Im),이원찬(Won Chan Lee),이문진(Moonjin Lee),최훈(Hoon Choi) 한국해양환경·에너지학회 2022 한국해양환경·에너지학회 학술대회논문집 Vol.2022 No.11

Organophosphate flame retardants (OPFRs) in water and sediment: Occurrence, distribution, and hotspots of contamination of Lake Shihwa, Korea

Lee, Sunggyu,Cho, Hyun-Jin,Choi, Woosik,Moon, Hyo-Bang Elsevier 2018 MARINE POLLUTION BULLETIN Vol.130 No.-

<P><B>Abstract</B></P> <P>Contamination by organophosphate flame retardants (OPFRs) is an emerging concern in aquatic environments. Concentrations of 18 OPFRs were measured in water and sediments collected from the artificial Lake Shihwa. OPFR concentrations in sediments measured in this study were the highest reported worldwide, implying severe OPFR contamination. The highest concentrations of OPFRs were found in creeks taken near industrial complexes, and OPFR concentrations decreased with increasing distance from creeks to inshore or offshore lake waters. On-going OPFR contamination by wastewater treatment plant (WWTP) discharge was evidenced by the clear decrease in OPFRs in water samples collected moving away from WWTP outfall. TBEP and TEP were dominant in water samples, while TDCPP and TCPP were dominant in sediment samples. Differences in contamination profiles with sample matrices are likely due to hydrophobicity of individual OPFRs. Non-parametric multidimensional scaling ordination showed that OPFR contamination was affected by pollution inflow and proximity to industrial complexes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Eighteen OPFRs were measured in water and sediments from industrialized coastal waters. </LI> <LI> Concentrations of several OPFRs in creek sediments were the highest reported worldwide. </LI> <LI> Clear decrease in OPFRs was found in water collected moving away from WWTP outfall. </LI> <LI> TBEP and TEP were dominant in water, while TDCPP and TCPP were dominant in sediments. </LI> <LI> Severe OPFR contamination was influenced by inflow of pollution and proximity of industrial complexes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Perfluoroalkyl substances (PFASs) in breast milk from Korea: Time-course trends, influencing factors, and infant exposure

Lee, Sunggyu,Kim, Sunmi,Park, Jeongim,Kim, Hai-Joong,Choi, Gyuyeon,Choi, Sooran,Kim, Sungjoo,Kim, Su Young,Kim, Sungkyoon,Choi, Kyungho,Moon, Hyo-Bang Elsevier 2018 Science of the Total Environment Vol.612 No.-

<P><B>Abstract</B></P> <P>Breastfeeding is an important exposure pathway to perfluoroalkyl substances (PFASs) for newborn infants. Nevertheless, reports are limited on the occurrence and time-course of PFASs in breast milk, and most studies have focused on the analysis of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In this study, 16 PFASs were analyzed in breast milk samples (<I>n</I> =293) collected from 128 mothers in Korea during various lactation periods to assess maternal exposure levels, contamination profiles, time-course variations, and infant health risks. The total concentrations of PFASs (ΣPFAS) ranged from 31.7 to 1004 (median: 188) ng/L, which was within the ranges recently reported for Asian and European populations. After a month of nursing, the concentrations of PFOS, PFOA, perfluorononanoic acid (PFNA), and ΣPFAS significantly increased. This could be due to changes in the dietary and behavior patterns of the mothers after the first month of lactation. The concentrations of PFOS and PFOA were significantly correlated with maternal age, body mass index, and parity. Certain types of diet (e.g. consuming snacks and milk) and eating-out frequency were significantly associated with increasing levels of PFAS. Significant correlations and similar time-course trends were found between PFASs and PCBs/DDTs, implying similar exposure sources and biokinetics for these contaminants. The estimated daily intakes of PFOS and PFOA via the consumption of breast milk were below the tolerable daily intakes for infants suggested by the European Food Safety Authority (EFSA).</P> <P><B>Highlights</B></P> <P> <UL> <LI> PFOS, PFOA, PFUnDA, and PFNA were the predominant compounds in breast milk. </LI> <LI> Concentrations of PFASs were significantly correlated with maternal age, BMI, and parity. </LI> <LI> Increased levels of PFASs were found in breast milk after the first month of nursing. </LI> <LI> Snack consumption and frequency of eating-out were significantly associated with increased PFAS levels. </LI> <LI> The infant exposure levels of PFOS and PFOA via breast milk were lower than the TDI. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Optimization of suspect and non-target analytical methods using GC/TOF for prioritization of emerging contaminants in the Arctic environment

Lee, Sunggyu,Kim, Kitae,Jeon, Junho,Moon, Hyo-Bang Elsevier 2019 Ecotoxicology and environmental safety Vol.181 No.-

<P><B>Abstract</B></P> <P>Numerous chemicals have been manufactured through industrial activities and used as consumer products since the late 18th century. Non-target analysis is a new analytical tool to detect many chemicals in environmental samples and to prioritize emerging contaminants. In this study, suspect and non-target analytical methods were optimized using gas chromatography coupled with time-of-flight (GC/TOF) to propose contaminants of emerging concern for the Arctic environment. A suspect analytical method was developed with qualification and qualifier ions, isotopic ratios, and retention times of 215 contaminants including persistent organic pollutants (POPs) to establish an in-house library. Non-target analytical method was also optimized with a deconvoluted ion chromatogram, which is a form that can possibly match the mass spectrum of the NIST library. Multiple environmental samples, such as seawater, air, soil, sediment, sludge, and iceberg, collected from the Arctic region were analyzed with suspect and non-target analysis of GC/TOF after the clean-up procedure with a solid phase extraction (SPE) cartridge. The commonly detected contaminants in the Arctic environmental samples were siloxanes, organophosphate flame retardants, phthalates, synthetic musk compounds, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Among them, siloxanes and organophosphate flame retardants were proposed to be contaminants of emerging concerns for the Arctic environment. This is the first report to prioritize emerging contaminants in the Arctic environment with suspect and non-target analysis of GC/TOF.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Suspect and non-target analytical method were optimized with GC/TOF. </LI> <LI> In-house library over 200 contaminants was established for suspect analysis. </LI> <LI> Prioritization workflow was applied for multiple environmental samples from the Arcitic. </LI> <LI> Siloxanes and OPFRs were proposed as emerging pollutants in the Arctic environment. </LI> <LI> This is the first report on suspect and non-target analysis for the Arctic environment. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Occurrence and seasonal changes of synthetic musk compounds (SMCs) in receiving waters from four major rivers of Korea

Sunggyu Lee(이성규),Tae-Jin Park(박태진),Kyungho Choi(최경호),Hyo-Bang Moon(문효방) 환경독성보건학회 2021 한국독성학회 심포지움 및 학술발표회 Vol.2021 No.5

Synthetic musk compounds (SMCs) are typical anthropogenic organic contaminants used as additives in many consumer products. SMCs could enter into the aquatic environment through effluents of wastewater treatment plants (WWTPs). Several studies reported that acute and chronic toxicity to aquatic organisms. In this study, surface water, sediment, and biota samples were collected from four major rivers of Korea in 2020, and were determined for 12 SMCs using a gas chromatography coupled to tandem mass spectrometer. Among analyzed SMCs, HHCB, DPMI, MK, and AHTN were detected in water samples. Mean concentrations of SMCs (ΣSMC) was 229, 99.8, 85.6, and 90.5 ng/L in Han, Gum, Yeongsan, and Nakdong Rivers, respectively. The major SMCs in Korean rivers was HHCB followed by MK, DPMI, and AHTN. The concentrations of HHCB and AHTN measured in our study were within the ranges of those reported for other countries. Seasonally, ΣSMC was the highest in winter. The next highest concentration was spring, autumn, and summer. These seasonal variations of SMCs concentrations are related to precipitation and temperature of each season. Similar with the results in water, HHCB (mean: 6.94 ng/g dw for sediment and 1999 ng/g lw for biota), AHTN (1.38 ng/g dw and 311 ng/g lw), and MK (0.04 ng/g dw and 245 ng/g lw) show at detectable concentrations in sediment and biota samples. An ecological risks of SMCs to aquatic organisms were assessed by comparing with PNEC value. The results showed that SMCs were negligible to pose an ecological risk to aquatic organisms in Korean rivers.

Emission of bisphenol analogues including bisphenol A and bisphenol F from wastewater treatment plants in Korea

Lee, Sunggyu,Liao, Chunyang,Song, Geum-Ju,Ra, Kongtae,Kannan, Kurunthachalam,Moon, Hyo-Bang Elsevier 2015 CHEMOSPHERE - Vol.119 No.-

<P><B>Abstract</B></P> <P>Due to the regulation on bisphenol A (BPA) in several industrialized countries, the demand for other bisphenol analogues (BPs) as substitutes for BPA is growing. Eight BPs were determined in sludge from 40 representative wastewater treatment plants (WWTPs) in Korea. Total concentrations of BPs (ΣBP) in sludge ranged from <LOQ to 25700ngg<SUP>−1</SUP>. The highest concentrations of ΣBP were found in sludge collected from WWTPs that received discharges from the paper and textile industries. The profiles of BPs were dependent on the proportions of industrial wastewater treated at each of the WWTPs. The sludge from industrial WWTPs contained elevated proportions of BPA, whereas sludge from domestic WWTPs was dominated by bisphenol F (BPF), suggesting use of BPF in certain industrial products in Korea. No significant correlations were found between BPs and the WWTP characteristics. The average per-capita emissions of BPs ranged from 0.04 (BPP) to 886gcapita<SUP>−1</SUP> d (BPA) through WWTP discharges. The emission fluxes of ΣBP through industrial WWTPs were 2–3 orders of magnitudes higher than those calculated for domestic WWTPs, indicating that industrial discharges are the major source of BPs into the Korean environment. This is the first nationwide survey of BPs in sludge from Korean WWTPs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Occurrence of several BP analogues in sludge was confirmed. </LI> <LI> High levels of bisphenol A were found in industrial WWTP sludge. </LI> <LI> Emission fluxes of bisphenols via WWTPs in Korea were estimated. </LI> <LI> This is the first nationwide survey to determine BP analogues in sewage sludge of Korea. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

An optimized method for the analysis of cyclic and linear siloxanes and their distribution in surface and core sediments from industrialized bays in Korea

Lee, Sang-Yoon,Lee, Sunggyu,Choi, Minkyu,Kannan, Kurunthachalam,Moon, Hyo-Bang Elsevier 2018 Environmental pollution Vol.236 No.-

<P><B>Abstract</B></P> <P>Environmental contamination by siloxanes is a matter of concern due to their widespread consumption in personal care as well as industrial products and potential toxicity. Nevertheless, methods for simultaneous determination of cyclic and linear siloxanes in sediment are lacking. In this study, we developed an optimized analytical method to determine cyclic and linear siloxanes based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). This method was applied to determine concentrations of 19 siloxane compounds in surface and core sediments from industrialized bays in Korea to assess contamination status, spatial distribution, and historical trends. Total concentrations of siloxanes ranged from 15.0 to 11730 (mean: 712) ng/g dry weight, which were similar to or higher than those reported in other countries. The highest concentrations of siloxanes were found in rivers/streams that discharge into coastal waters and bays close to industrial complexes, indicating that industrial activities are major sources of siloxane contamination. Cyclic siloxanes such as D5 and D6 were predominant in surface and core sediments. A significant correlation existed between the concentrations of cyclic and linear siloxanes, suggesting similar sources in the marine coastal environment. The historical record of cyclic siloxanes in core sediments revealed a clear increasing trend since the 1970s. This finding is consistent with the history of local industrialization and global production of siloxanes. This is the first study of historical trends in siloxanes in the coastal environment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An optimized method was developed for simultaneous determination of cyclic and linear siloxanes in sediment. </LI> <LI> Highest levels of linear siloxanes were found in stream sediment. </LI> <LI> Cyclic siloxanes such as D5 and D6 were predominant in surface and core sediments. </LI> <LI> Historical record of siloxanes in sediment core showed a clear increase since the 1970s. </LI> <LI> Historical trend of siloxanes matched well with the history of industrialization and global production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Passive Bypass Using Anthron Tube in Adult Living Donor Liver Transplantation

SungGyu Lee,Shin Hwang,KiHoon Kim,ChulSoo Ahn,KwangMin Park,YoungJoo Lee,DeokBog Moon,ChongWoo Chu,HyunSeong Yang,SungHoon Cho,KiBong Oh,TaeYong Ha,KiWon Song,YunSik Yu,PyungChul Min 대한외과학회 2002 대한외과학회 학술대회 초록집 Vol.2002 No.10

확률변수 다항식 확률모멘트를 활용한 구조신뢰성 해석

이승규(Sunggyu Lee),신정우(Jeong Woo Shin),김성찬(Sung-Chan Kim),김태욱(Tae-Uk Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

Uncertainties and failure criteria of structure are mathematically expressed by random variables and a limit state equation. A limit state equation is approximated by polynomials and the moments of an approximated limit state equation is calculated. A cumulative distribution function of a limit state equation are approximated by a pearson system.