• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.398-405
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• 2012

PAHs(Polycyclic Aromatic Hydrocarbons) in coastal area and estuary adjacent to urban area and industrial activities region are mainly introduced into marine environment via atmosphere and river. This study which is evaluated the distribution characteristics of PAHs discharge from rivers and sewage disposal water which flowing into Ulsan bay, and were carried out in Jun of dry season and in Auguest of wet season, 2008. The water samples from eight main rivers and Youngyeon WWTP(Wastewater Treatment Plant) flowed into Ulsan bay were taken for analysis of dissolved PAHs. The range and mean values of dissolved PAHs concentrations showed 10.30 to 87.88 ng/L, its mean 36.94 ng/L in dry season and 10.30 to 69.57 ng/L, its mean 24.37 ng/L in wet season. The distribution of dissolved PAHs showd the high concentrations in the Gungcheoncheon which is flowed from urban and industrial area. The ranges and means values of the loading fluxes were estimated with 0.04 to 8.27 g/day, its mean 2.05 g/day in dry season, and 0.03 to 4.77 g/day, its mean 1.61 g/day, in wet season. The loading flux showed the highest value in Taewha river due to the high flow rate and the urban activity. The composition patterns of dissolved PAHs compound showed most of the trend occupying low molecuar weight PAHs than high molecular weight PAHs. These results were due to physical and chemical characteristics of PAHs compound, and were similar to those of other studies. The concentrations of dissolved PAHs in this study are lower than those of other studies, and the level of PAHs pollution appeared to be not serious in reverine waters of Ulsan coast.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.513-520
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• 2020

Here, we evaluated the functional properties of histidine-containing low-molecular-weight (LMW) peptides obtained from tuna waste meats. As with histidine-related components composed of histidine, 1-methyl histidine and anserine, histidine-containing LMW peptides exhibited high α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging effect in a dose-dependent manner. Among the histidine-related dipeptides, anserine exhibited the highest reducing power followed by carnosine. By comparison with dipeptides, tuna extracts also showed similar reducing power and the activity was in a dose-dependent manner. In addition, the antioxidant activities of tuna extracts such as DPPH radical scavenging effect, reducing power, superoxide dismutase activities, and peroxide value of linoleic acid were affected by the various extraction methods.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.443-454
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• 2010

Phthalate compounds are widely used as plasticizers in polyvinyl chlororide (PVC) resins and other industrial consumer products, and some of them are known to be endocrine disruptors. In Korea, a number of studies have been carried out for the measurement of phthalates in consumer products and drinking water. However, no data are available for those compounds in the ambient air where the general public are routinely exposed. In this study, we evaluated sampling and analytical methods for the determination of phthalates in the ambient atmosphere. A wide range of phthalates compounds were included in the target analytes, which are dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP). Most of samples were collected using a high volume sampler with a PUF/XAD-2 column/quartz fiber filter and then analyzed by GC/MS. Some of samples were simultaneously collected on XAD-2 using a low-volume sampler, together with high-volume samples. The analytical method applied in this study showed good repeatability and linearity. Quantitative detection limits were estimated from 0.60 to 17.84 ng/$m^3$ in air, depending on individual compounds. The field measurements were carried out at 3 sites located in Sihwa- Banwall industrial areas and a suburban area from January 2007 to November 2007. From the field experiments, DEHP, DMP and DBP appeared to be the most abundant compounds in the ambient air. It was also found that DMP, DEP and DBP were mainly distributed in the vapor phase, while BBP, DEHP and DOP were predominantly associated with the particulate phase. The concentrations of DEHP and DMP in the industrial areas ranged from 45.7 to 1,012.7 ng/$m^3$ and from 7.7 to 375.1 ng/$m^3$, respectively. Overall, the high-volume sampling method was demonstrated to be superior to the low-volume method for the determination of phthalates in the ambient atmosphere.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.275-282
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• 2009

PAHs(Polycyclic Aromatic Hydrocarbons) compounds may enter into the marine environment in a number of ways, and PAHs in coastal area and estuary adjacent to urban area and industrial activities region are mainly introduced into marine environment via atmosphere or river. The field surveys to evaluate the pollution of PAHs in rivers of Jinhae bay were carried out in August, 2008. The water samples collected from seven main rivers and Deokdong WWTP(Waste water Treatment Plant) which lead to Jinhae bay. 16 PAHs which had been selected as priority pollutants by EPA were analyzed. The range and mean of dissolved Total PAHs concentrations in the rivers and Duckdong WWTP that lead to Jinhae bay were shown to be 9.79~128.25(mean 36.94)ng/L, while the range and mean of Total PAHs concentrations in SPM(Suspended Particulate Matter) were shown to be 1,81434~8,893.37(mean 4,657.73)${\mu}g$/kg dry wt. The dissolved Total PAHs and Total PAHs in SPM were shown to be high concentrations in the Semhocheon which leads to Masan bay that is the most polluted area of Jinhae bay, while those were shown to be low concentrations at rivers which lead to the west area of the bay. The ranges and means of the loading fluxes from rivers and Duckdong WWTP were calculated at 0.06~12.05(mean 1.86)g/day for dissolved Total PAHs and at 0.12~16.00(mean 2.41)g/day tor Total PAH in SPM. The loading flux of Total PAHs from Duckdong WWTP was shown to be the greatest, occupying more than 80% of Total loading flux from all rivers and WWTP to Jinhae bay. The composition patterns of PAHs compound by the number of benzene ring between dissolved PAHs and PAHs of SPM were different each other. Low molecuar weight PAHs of dissoloved compounds were in high concentration, while high molecular weight PAHs of SPM were in high concentration. These results were due to physical and chemical characteristics of PAHs and were similar to those of other studies. The total PAHs concentrations of dissolved and SPM in this study are lower than those of other studies. The extent of PAHs pollution appeared to be not serious in reverine waters of Jinhae bay.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.462-466
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• 2004

Mycothiol (MSH), a low molecular antioxidant thiol compound, was purified and analyzed from Streptomyns coelicolor A[3]2 by the monobromobimane fluorescence detection method modified by this lab. Through HPLC chromatpgram, MSH fraction was obtained following the elution time of standard MSH (donated by Dr. Robert C. Fahey). That MSH showed the highest concentration among the thiol compounds contained in the cell indicated that MSH was the key thiol compound having antioxidant activity. To understand the role of gene of inositol monophosphatase (I-1-Pase) involved in the MSH biosynthesis, it was isolated from S. coelicolor A(3)2 and cloned and overexpressed in the Escherichia coli. The expressed I-1-Pase was purified through Ni-NTA column. The soluble protein consisted of 281 amino acids, and the molecular weight was 32 kDa. I-1-Pase of S. coelicolor A(3)2 had the sequence homology with those of human and E. coli by 24 and $25\%$, respectively, and had two conserved domains (mofif A and motif B) which were typical of I-1-Pase.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.690-696
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• 2005

The characteristics of hydrospheric concentration and distribution of polycyclic aromatic hydrocarbons (PAHs) in the Lake of Sihwa were investigated on this study. Sediment and Surface water samples were collected from upstream and downstream in Lake of Sihwa. The total PAHs concentrations of surface water were $21.9{\sim}49.6\;ng/L$ at upstream and $19.4{\sim}99.7\;ng/L$ at downstream, respectively. Most of the PAHs existed in the dissolved phase with average 87%. In the case of sediment samples, total PAHs concentrations were $51.7{\sim}325\;ng/g-dry$ at upstream and $13.4{\sim}72.3\;ng/g-dry$ at downstream, respectively. Low-and-middle molecular weight of PAHs were dominated in dissolved phase of the surface water, while middle-and-high molecular weight compounds were predominantly present in the particular phase of the surface water and sediment. The average slope obtained from the plots of log-log scaled dissolved/solid partition coefficient vs. octanol/water partition coefficient was $0.73{\pm}0.12$ and the slope from the water/sediment partition coefficient was $0.59{\pm}0.10$. These results indicated that distribution of PAHs between the dissolved phase and the solid phase was not at equilibrium as well as between water and sediment.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.298-299
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• 2012

현재 반도체 나노구조는 단전자 트랜지스터, 레이저, LED, 적외선 검출기 등과 같은 고효율 광전자 소자에서의 응용을 위해 활발한 연구가 진행 되고 있다. 이러한 응용 분야를 위한 다양한 종류의 나노구조 성장이 광범위하게 시도 되고 있지만 주로 III-V 족 화합물 반도체에 대한 연구가 주를 이룬 반면 II-VI 족 화합물 반도체에 대한 연구는 아직 미흡하다. 하지만 II-VI 족 화합물 반도체는 III-V 족 화합물 반도체와 비교했을 때 더 큰 엑시톤 결합에너지(exciton binding energy)를 가지는 우수한 특성을 보이고 있으며 이러한 성질을 가지는 II-VI 족 화합물 반도체 중에서도 넓은 에너지 갭을 가지는 CdTe 양자점은 녹색 영역대의 광전자 소자로서 활용되고 있다. 본 연구에서는 분자 선속 에피 성장법(molecular beam epitaxy; MBE)과 원자 층 교대 성장법(atomic layer epitaxy; ALE)으로 CdTe 두께에 따른CdTe/ZnTe 나노구조의 광학적 특성을 연구하였다. 광루미네센스(photoluminescence; PL)를 통해 CdTe/ZnTe 나노구조에서 CdTe 두께에 따른 에너지 밴드와 열적 활성화 에너지를 관찰하였다. 또한 시분해 광루미네센스(Time-resolved PL)를 통해 CdTe 두께에 따른 CdTe/ZnTe 나노구조의 운반자 동역학을 조사하였다. 저온 광루미네센스 측정 결과 CdTe 두께가 증가할수록 각 샘플의 피크는 더 낮은 에너지 영역대로 이동하는 것을 관찰할 수 있다. 1.2 에서 2.0 ML로 증가할 때 광 루미네센스의 작은 적색편이를 관찰할 수 있는데, 이는 CdTe 양자우물에서 양자점으로의 구조적인 전이가 일어남에 따라 구속효과가 증가하였기 때문이다. 또한 2.0 에서 3.6 ML까지 CdTe 두께가 증가할 때 측정된 적색편이 현상은 양자점의 사이즈 증가함에 따른 것이다. 마지막으로 3.6 에서 4.4 ML로 CdTe 두께가 증가할 때 큰 적색편이 현상을 볼 수 있는데 이는 CdTe 양자점에서 양자세선으로의 구조적 전이에 따라 구속효과가 증가하였기 때문이다. 온도 의존 광루미네센스(Temperature-dependent PL) 측정 결과 1.2 와 3.0 ML 두께의 CdTe/ZnTe 나노구조에서 구속된 전자의 열적 활성화 에너지가 18 과 35 meV로 관찰되었다. 3.0 ML CdTe/ZnTe 나노구조에서 가장 큰 열적 활성화 에너지를 갖는 것은 양자점의 균일도가 좋아지고 저차원 나노구조로의 구조적 전이가 일어나면서 운반자 구속효과에 다른 쿨롱 상호작용이 증가하였기 때문이다.

• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.20-27
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• 2001

The consumption of radish ( Rhaphanus sativus L.) sprout, which is Cruciferae family, is increasing because of its pungent flavor and taste. Its volatile components were analyzed by SDE (simultaneous steam distillation & extraction) method and P&T(purge & cryogenic trapping) method. As a solvent, diethyl ether and diethyl ether : pentane mixture(2:1, v/v) were used in SDE method, and diethyl ether in P&T method. Analyzing by GC and GC-MS, the major component was sulfur compounds (19 species, peak area 76.6%) with diethyl ether, sulfur compounds(15. 44.0%) and hydrocarbons(23, 23.8%) with diethyl ether-pentane mixture in SDE method. Also, hydrocarbons(25, 84.1% ) was major component in P& T method. The major volatile component of fresh radish sprout were n-heptane, methyl pentane and that of boiled radish sprout were 4-methylthio-3-butenyl isothiocyanate, methyl mercaptane, 2,3-dimethyl disulfide. Low molecular volatile components were detected more by P& T method, but types and relative quantities of volatile components were measured less comparing to SDE method.

• Polymer(Korea)
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• v.25 no.5
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• pp.625-634
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• 2001

New polymeric photostabilizers containing hindered amine light stabilizer (HALS) were prepared by the reaction of liquid polyisoprene rubber grafted maleic anhydride (MAH) and 2,2,5,6-tetramethyl-4-piperidinol (TMPO). Their chemical composition and physical properties were characterized by titration, GPC and TGA analysis. The effects of polymeric HALS on the photooxidation of the styrene-butadiene rubber were studied from the UV, IR spectral changes, and photo-crosslinking was examined by the measurement of the insoluble fraction. The photooxidation of SBR upon irradiation was inhibited by addition of the new polymeric HALS. The extraction resistance of new polymeric photostabilizer was much better than that of the low molecular weight compound which is prepared by the reaction of MAH and TMPO. The new polymeric HALS ate fairly compatible with the SBR.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.361-364
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• 2002

BAC (biological activated carbon) process is a combination of biodegradation and active carbon adsorption. Pre-ozonation of raw water increased in biodegradable organic fraction. This study is to investigate the enhancement of dissolved organic matter removals by pre-ozonation process combined with BAC process at a semi-pilot scale. By biodegradation improvement in pre-ozonation process. the charge of adsorption was reduced and the life of biological activated carbon is extended. And, 48 % of total DOC was remove in the upper compartment of BAC column. The removal of the nitrogen-ammonia shows a considerably high removal ratio with 75.9 %.