• 한국대기환경학회지
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• 제13권2호
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• pp.161-170
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• 1997

The concentrations of dimethylsulfide (DMS) were determined using samples collected from a station located at Kosan, Cheju Island during two field campaigns held in December 1996 and January 1997. The atmospheric DMS concentrations measured at 6-hr intervals during the entire campaign periods, after excluding a few extreme values, spanned in the range of 14 to 410 pptv with mean and 1 SD value of 127 $\pm$ 94 pptv (N=42). Between two month periods during which the field campaigns were conducted, a notable reduction in DMS levels was observed which was comparable to the dramatic shift in air temperature. A considerable difference was also noted in DMS levels, when data were grouped by day/night basis. The cause of unexpected, high day-to-night DMS ratios is best explained in terms of high efficiency of daytime source processes relative to low efficiency of nighttime sink processes due to the characteristics of the study location. The surface water DMS of the study site, although scarcely measured, also behaved similarly to its atmospheric counterpart with its range from 0.3 to 19 nM (N=11). When correlation analysis was conducted between the atmospheric DMS concentration and other concurrently determined parameters, significant correlations were observed from most basic meteorological parameters such as windspeed, relative humidy, and air temperature. However, the existence of "not-so-strong" correlations between air temperature and DMS concentrations relative to other ones indicated that the effect of temperature on DMS behavior must be reflected in more complicated manners at the study site. The sea-to-air flux of DMS was approximated through an application of the mass-balance flux calculation method of Wylie and de Mora (1996) under the assumption that sink mechanism within the marine boundary layer is in steady-state condition with its counterpart, source mechanism. Based on this estimation method, we reached a conclusion that oceanic DMS emitted from the southwest sea of the Korean Peninsula can amount to approximately 9 $\sim$ 36 Gg S $yr^{-1}$.$yr^{-1}$.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권3호
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• pp.139-148
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• 2000

A mass balance/photochemical modeling approach was used to evaluate the sea-to-air dimethyl sulfide (DMS) fluxes in tropical regions and part of the Southern Ocean. The flux determinations were based on 10 airborne observations by ACE 1 transit flights (i.e., Flights 4-9 and 29-32). The DMS flux values for the tropical regions ranged from 1.0 to 7.4 $\mu$mole/$m^2$/day with an average estimate of 4.2$\pm$2.3 $\mu$mole/$m^2$/day. The seasonal variations in the DMS flux predicted for the equatorial Pacific Ocean based on atmospheric DMS measurements were not entirely consistent with those derived from seawater DMS measurements were not entirely consistent with those derived from seawater DMS measurements reported in previous literature. Inhomogeneities in the DMS flux field were found to cause significant shifts in the atmospheric DMS levels even in the same sampling location. Accordingly, no definitive statement can be made at this stage regarding systematic differences or agreements in the DMS flux estimates from the two approaches. Moreover, this study strongly suggests that DMS oxidation is the most likely dominant source of SO$_2$in tropical regions, which is also supported by another set of compiled observations. Finally, these SO$_2$observations indicate that, when significant data was available for both the boundary and buffer layers, the vertical SO$_2$gradient between these two zones was primarily negative.

• Journal of Korean Society for Atmospheric Environment
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• 제15권E호
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• pp.39-43
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• 1999

To help idntify the potential sources of volatile organic sulfur compounds within the continental environment, we have conducted preliminary measurements of dimethylsulfide(DMS) during field campains held from three reference sites. These sampling sites were located within a waste reclamation facility in Won Ju City, Kang Won Province. The results of our measurements showed that DMS levels spanned over 1 to 55 pptv with a mean and 1 standard deviation(1SD) of 12 and 18 pptv(N=13). In a comparison of the data derived from the strongest sources, i.e., oceanic environment, the DMS levels in thre reclamation facility were jpronouncingly low with high day-to-night concentration ratios. It was noted that a significant difference in DMS levels between daytime and nighttime periods was mainly driven by a few exceptional data measured during daytime. Despite limitations of our measurement data in deriving meaningful interpretations of spatiotemporal distributions of DMS in inland facilities, the existence of extraordinary trends, i.e., especially "lower-than-expectedL" DMS values, can be explained in terms of mixed effects of several factors. Most importantly, we can infer that the rates of DMS production and of its destruction in the study site are at or near steady-state condition. Another possibility is that DMS is not adequate enough to explain the generally malordorous environment of reclamation sites, of particular in Won Ju area.n Ju area.

• 공업화학
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• 제21권1호
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• pp.93-97
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• 2010

친핵성 첨가반응에 의한 극성 용매(NMP, DMSO, DMF, m-cresol etc.)에 용해성을 갖는 이온성 액체(1,3-dimethylimidazolium methylsulfate, I-DMS)로 도핑된 폴리아닐린(PAN/I-DMS)을 합성하였다. 극성 용매 내에서 PAN/I-DMS의 용해도는 3~6 wt%/vol.을 나타내었고, PAN/I-DMS films의 전기전도도는 $10^{-2}{\sim}7S/cm$를 나타내었다. PAN/I-DMS는 HCl로 도핑된 폴리아닐린(PAN/HCl)과 dimethylsulfate (DMS)로 도핑된 폴리아닐린(PAN/DMS)에 비하여 $160^{\circ}C$에서 열적 안정성과 전기 전도성이 우수함을 볼 수 있었다. 극성 용매 내에서의 용해도와 전기 전도도 증가 현상을 극성 sulfonate group과 극성 용매간의 상호 작용으로 설명하였다.

• KSBB Journal
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• 제19권2호
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• pp.143-147
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• 2004

휘발성 황화합물 중 생물학적으로 가장 난분해성으로 알려 져 있는 DMS에 대한 분해능이 우수한 신균주를 분리. 동정 하여 Gordonia sihwaniensis PKL-1로 명명하였다. 이 균주는 D DMS 초기농도가 35 mg/L 이상일 때에도 우수한 분해능을 보였고, 회분식 배양에서 최대 비분해속도 $\upsilon_{max}$ 없는 0.0016 mg/(mg-protein).hr이 었고, 최적 의 온도와 pH는 각각 $25^{\circ}C$ 와 pH는 7이였다.

• Molecules and Cells
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• 제23권1호
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• pp.11-16
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• 2007

N,N-dimethyl-D-erythro-sphingosine (DMS) is an N-methyl derivative of sphingosine and an inhibitor of protein kinase C (PKC) and sphingosine kinase (SK). In the present study, we examined the effects of DMS on intracellular $Ca^{2+}$ concentration, pH, and glutamate uptake in human 1321N1 astrocytes. DMS increased intracellular $Ca^{2+}$ concentration and cytosolic pH in a concentration-dependent manner. Pretreatment of the cells with the $G_{i/o}$ protein inhibitor PTX and the PLC inhibitor U73122 had no obvious effect. However, removal of extracellular $Ca^{2+}$ with the $Ca^{2+}$ chelator EGTA or depletion of intracellular $Ca^{2+}$ stores with thapsigargin impeded the DMS-induced increase of intracellular $Ca^{2+}$ concentration. Pretreatment of cells with $NH_4Cl$ or monensin reduced the DMS-induced $Ca^{2+}$ increase. However, inhibition of the DMS-induced $Ca^{2+}$ increase with BAPTA did not influence the DMS-induced pH increase. DMS also inhibited glutamate uptake by the 1321N1 astrocytes in a concentration-dependent manner. It also increased intracellular $Ca^{2+}$ and pH in PC12 neuronal cells. Our observations on the effects of DMS on 1321N1 astrocytes and PC12 neuronal cells point to a physiological role of DMS in the brain.

• 한국대기환경학회지
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• 제12권4호
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• pp.495-504
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• 1996

The concentrations of dimethylsulfide (DMS) were determined from both seawater and the overlying atmosphere from a station located in the Masan Bay area during a ten-day field campaign period of January 1996. The resulting data were also used to derive saturation ratios (SR) as well as sea-to-air fluxes of DMS. The concentrations and fluxes of DMS for both reservoirs varied extensively over two to three orders of magnitude: DMS in air and seawater were measured at 9 to 4,300 pptv (mean: 600 $\pm$ 1, 170, N=18) and at 0.24 to 10 nM (4.0 $\pm$ 3.4, N=13), respectively, while its fluxes were found from 0.02 to 23 mol $m^{-2} day^{-1} (3.1 \pm 6.8, N=11)$. A comparative analysis between our data and previously reported ones indicate that its atmospheric concentrations are abnormalously high, but its seawater counterparts are slightly lower than expected. In light of high pollution levels of organic-rich materials in and the associated high biological productivity of the study area, the sea-to-air-fluxes derived are notably low relative to those values typically reported from the coastal areas. These complicated features of DMS distributions/fluxes in the study site indicate that the near-by port- based anthropogenic activities from various industrial plants strongly interfere with natural processes leading to the production and release of DMS. It was however striking to find out relatively strong signals of diel cycle in its saturation ratios, concentration gradients between seawater and atmosphere, and the associated fluxes. Although it is yet difficult to provide meaningful explanations for the observed phenomena, the existence of clear diel cycle in some DMS-related parameters suggests that the natural processes may nonetheless exert important controls on the regional cycling of atmospheric sulfur species, of particular DMS.

• 한국지구과학회지
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• 제21권1호
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• pp.51-58
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• 2000

황해지역에서 생성 및 배출되는 자연황화합물의 규모를 정량적으로 구명하기 위한 노력의 일환으로, 본 연구진은 황해에 위치한 덕적도를 주 측정점으로 설정하고 대기 중에 존재하는 DMS의 농도분포를 1999년 4월과 9월 2차례의 집중측정기간을 통해 측정하였다. 그리고 이에 덧붙여 1999년 6월에는 청도-인천간 해상실험을 통해 황해상의 DMS 농도를 측정하였다. 덕적도를 중심으로 시행한 양 측정기간 중 DMS의 농도값은 4월 측정의 경우 평균과 표준오차가 $24.0{\pm}40.5$ pptv(n=40)인데 반해 9월 측정의 경우 $61.1{\pm}37.9$ pptv(n=35)로 나타났다. 그리고 선상실험에서 측정한 DMS 값은 대체로 배경농도에 가까운 낮은 농도범위를 갖는 것으로 밝혀졌다. DMS의 농도분포는 일반적으로 불규칙한 양상을 보였지만, 주변 기상인자의 변화경향과 유사하게 변화하는 것으로 나타났다. 본문에서는 이러한 연구결과와 기존의 연구결과 등을 연계하여 잠정적인 연간 배출량규모를 4Gg 대로 추정하였다. 이러한 배출규모는 과거 제주지역 등을 중심으로 측정한 결과에 비해 상대적으로 낮은 수치인데, 시간적 및 공간적으로 대표성이 강한 보다 객관적인 배출량을 산정하기 위해서는 추가적인 측정 자료의 축적이 요구된다.

• Ocean and Polar Research
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• 제27권2호
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• pp.197-203
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• 2005

Dimethylsulfide (DMS) is the most abundant form of volatile sulfurs in the ocean. Many biogeochemical studies have been conducted in the past several decades to unveil the processes driving the production, transformation and removal of DMS. They have shown that the Southern Ocean is an area with one of the highest levels of DMS concentrations during the austral summer in the global oceans. It has recently been observed that Antarctic krill, Euphausia superba, produces DMS and dissolved dimethyl-sulfoniopropionate (DMSP) in its gazing process. Copepods also produce DMS, and the potential production rates of DMS in the Southern Ocean by krill and copepods are estimated to be as much as $21{\mu}mol\;m^{-2}d^{-1}$ and $0.6{\mu}mol\;m^{-2}d^{-1}$, respectively. These production rates of zooplankton and the presence of phytoplanktot which have high DMSP contents in their cells, might facilitate in situ DMS production in the Southern Ocean.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2002년도 추계학술대회 논문집
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• pp.343-343
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• 2002

This study examines the influence of long-range transport of dust particles and air pollutants on both local/regional DMS oxidation chemistry and the distribution of sulfur compounds at Jeju Island (33.17$^{\circ}$ N. 126.10$^{\circ}$ E) during the Asian dust-storm(ADS) period in April 2001. The atmospheric concentrations of these sulfur species were measured at a ground station on Jeju Island. Korea as Part of the ACE-Asia intensive operation. Three ADS events were observed during the periods of 10-12, 13-14. and 25-26 April. respectively. The concentrations of DMS and CS$_2$ were higher during the ADS period than during the non-Asian-dust-storm (NADS) period. Conversely. a difference in SO$_2$ levels during the ADS period was not distinguishable from those during the NADS period. The diurnal variation pattern of DMS observed was largely different from that in the remote marine boundary layer. DMS loss by NO$_3$ in the atmospheric boundary layer was dominant due to significantly high NOx levels influenced by the long-range transport of pollutants from East Asia to Jeju Island The DMS maximum during the ADS period was observed in the late afternoon. The oceanic fluxes of DMS during the ADS and NADS periods were estimated to be 5.7$\pm$2.3 and 2.9 (+2.8/-1.5) mole m$^{-2}$ day$^{-1}$ . respectively. The contribution of oxidized DMS to SO$_2$ levels at Jeju Island during the study period was found to be insignificant.