• Bulletin of the Korean Chemical Society
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• 제15권10호
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• pp.860-864
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• 1994

2nd-order rate constants have been measured spectrophotometrically for the reactions of 4-nitrophenyl benzoate (1), S-4-nitrophenyl thiobenzoate (2) and 4-nitrophenyl thionbenzoate (3) with alkoxides, aryloxides and thioaryloxides in absolute ethanol at 25.0 ${\pm}0.1$${\circ}C$. The substitution of O by polarizable S in the leaving group has little affected the reactivity of 2 toward the charge localized species (eg. $EtO^-$ and $CF_3CH_2O^-$), while the effect of the similar replacement in the carbonyl group has led to a decrease in reactivity by a factor of 10. However, the reactivity of these esters toward charge delocalized aryloxides has been found to be in the order $1<3{\le}2$. The effect of replaced sulfur atom on reactivity becomes more significant for the reaction with polarizable thioaryloxides, i.e. the reactivity increases in the order $1<2{\ll}3$. The difference in reactivity for the present system is attributed to a polarizability effect.

• Bulletin of the Korean Chemical Society
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• 제10권3호
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• pp.279-282
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• 1989

Two rhodium(I) complexes of the types [Rh(BPPF)(NBD)]$ClO_4$ (10) and [Rh(BPPF)$Cl]_2$ (11) (BPPF = 1,1'-bis(diphenylphosphino)-ferrocene) have been prepared and investigated as catalysts for the regioselective hydrogenation of polynuclear heteroaromatic nitrogen and sulfur compounds such as quinoline (1), acridine (2), phenanthridine (3), 7,8-benzoquinoline (4), benzothiophene (5), isoquinoline (6), indole (7), pyridine (8), and thiophene (9). Both complexes 10 and 11, except for the cases of indole (7) and mononuclear heteroaromatics 8-9, are very efficient in the selective reduction under quite mild hydrogenation conditions to give the corresponding saturated nitrogen and sulfur heterocyclic analogues of 1-6 in fast conversion rates and in excellent yields. Relative rate studies revealed that the reduction depends significantly on the steric and electronic effects of the substrates. Of the two complexes 10-11, the dimeric species 11 gives faster reaction rates in all cases studied.

• 천문학회지
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• 제37권4호
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• pp.131-135
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• 2004

The $H_2S\;(2_{2,0} - 2_{1,1})$ line emission is observed to be strongly localized toward Sgr B2(M), and emissions from other positions in the more extended SgrB2 region are almost negligible. $H_2S$ is thought to form effectively by the passage of the C-type shocks but to be quickly transformed to $SO_2$ or other sulfur species (Pineau des Forets et al. 1993). Such a shock may have enhanced the $H_2S$ abundance in Sgr B2(M), where massive star formation is taking place. But the negligible emission of $H_2S$ from other observed positions may indicate that these positions have not been affected by shocks enough to produce $H_2S$, or if they have experienced shocks, $H_2S$ may have transformed already to other sulfur-containing species. The $SO_2\;22_{2,20} - 22_{1,21}$ line was also observed to be detectable only toward the (M) position. The line intensity ratios of these two molecules appear to be very similar at Sgr B2(M) and IRAS 16239-2422, where the latter is a region of low-mass star formation. This may suggest that the shock environment in these two star-forming regions is similar and that the shock chemistry also proceeds in a similar fashion in these two different regions, if we accept shock formation of these two species.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.716-721
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• 2005

The role of an effective microbial species is critical to the successful application of biological processes to remove sulfur compounds. A bacterial strain was isolated from the soil of a malodorous site and identified as Burkholderia spp. This isolate was able to oxidize thiosulfate to sulfate, with simultaneous pH decrease and accumulation of elemental sulfur. The specific growth rate and the sulfate oxidation rate using the thiosulfate basal medium were $0.003 h^{-1}\;and\;3.7 h^{-1}$, respectively. The isolated strain was mixotrophic, and supplementation of $0.2\%$ (w/v) of yeast extract to the thiosulfate-basal medium increased the specific growth rate by 50-fold. However, the rate of sulfate oxidation was more than ten times higher without yeast extract. The isolate grew best at pH 7.0 and $30^{\circ}C$, and the sulfate oxidation rate was the highest at 0.12 M sodium thiosulfate. In an upflow biofilter, the isolated strain was able to degrade $H_2S\;with\;88\%$ efficiency at 8 ppm and 121/h of incoming gas concentration and flow rate, respectively. The cell density at the bottom of the column reached $3.2{\times}10^8$ CFU/(g bead) at a gas flow rate of 121/h.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 1997년도 가을 학술발표회 프로그램
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• pp.1.1-32
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• 1997

Atmospheric monitoring capabilities were established in 1988 by the University of Florida at Duke forest, near Durham. NC: Cary forest, near Gainesville, FL: and Austin forest, near Nacogdoches, TX. Continuous (hourly averaged) measurements of air quality (ozone, nitrogen oxides and sulfur dioxide) and meteorological variables were made at these three low elevation (< 200 meters), rural locations in the southeastern U.S. for more than three years. During the same period at these sites wet and dry acid deposition samples were collected and analyzed on an event and weekly basis, respectively The monitoring locations were selected to determine actual atmospheric exposure indices for southern pine species in support of on-site surrogate exposure chamber studies conducted by Southern Commercial Forest Research Cooperative (SCFRC) investigators. Daily and quarterly averaged ozone maxima were higher (55 ppb) at the northernmost site in the network (Duke forest) in the second and third quarters (spring and summer seasons) and lower (35 ppb) in the first and fourth quarters (winter and fall seasons), when compared to ozone levels at the two southernmost sites (Cary and Austin forests). Seasonal ozone levels at the latter two sites were similar Nitrogen oxieds and sulfur dioxide levels were insignificant (< 5 ppb) most of the time at all sites, although soil emissions of NO at two sites were found to influence nighttime ozone concentrations. Typical maximum quarterly and annual aggregate ozone exposure indices were significantly higher at Duke forest (92.5/259 ppm-hr) than those values observed at the two southern sites (65.6/210 ppm-hr). Acid deposition (wet and dry) components concentrations and deposition fluxes observed at the Duke forest, NC piedmont site, were generally greater, dependent on site and season, than corresponding variables measured at either of the two southern coastal plain sites (Cary and Austin forests). Acid deposition variables observed at the latter two sites were remarkably similar, both qualitatively and quantitatively, although the sites were located 1300 km apart. A comparison of deposition fluxes of elemental nitrogen (NO3, NH4') and sulfur (5042-, SO3) components in wet and dry forms indicated that wet deposition accounts for approximately 70% of the total nitrogen and 73% of the total sulfur input on an annual equivalent basis at all sites.

• 분석과학
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• 제28권3호
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• pp.175-181
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• 2015

Cyantraniliprole은 DuPont사에서 개발한 anthranilic diamide계 살충제로 나비목 팔랑나비과(Lepidopera), 딱정벌레목(Coleoptera), 파리목(Diptera)과 흰개미목(Isoptera)과 같은 해충에 효과가 뛰어나다. 국내의 경우 고추, 대파, 복숭아, 사과, 피망 등 15 품목에 잔류허용기준(0.2~2.0 mg/kg)이 설정되어 있어, 본 연구에서는 대파 중에 잔류할 수 있는 cyantraniliprole의 잔류분석시험법을 HPLC-VUD를 이용하여 개발하고자 하였다. Allium속에 포함되는 조미채소인 대파는 함유황 유기화합물을 가지고 있는 대표식물로 이를 제거하기 위한 전처리법 개발이 아주 중요하다. 이를 위해 함유황 유기화합물을 생성하는 allinase 효소를 불활성화시키기 위해 pH 10의 염기상태로 만들어서 효소의 활성을 감소시켜 황화합물의 생성을 감소시켰다. 확립된 시험법 검증을 위해 회수율을 측정한 결과 본 시험법의 회수율은 81.9~83.2%로 나타났으며, 분석오차는 10% 미만으로 코덱스가이드라인에 적합하였다. Cyantraniliprole의 정량한계는 0.05 mg/kg이었으며, 추가적으로 LC-MS를 통한 재확인 과정을 확립하였다. 활용될수 있다고 생각된다.

• 한국산림과학회지
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• 제81권2호
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• pp.164-176
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• 1992

조경수목(造景樹木)들의 대기오염물질(大氣汚染物質)들에 대한 감수성(感受性) 및 저항성(抵抗性)을 규명하기 위해서 야외조사(野外調査)와 실내실험(室內實驗)을 통하여 엽내(棄內) 유황함량(硫黃含量)과 superoxide dismutase(SOD) 함량(含量)을 측정(測定) 분석(分析)하였다. 전(全) 수종(樹種)에서 엽내(棄內) 유황함량(硫黃含量)과 SOD 활성간(活性間)에 정(正)의 상관(相關)을 나타내었다. 식물체(植物體)가 오염물질(汚染物質)에 대하여 자체방어(自體防禦)를 위하여 초기(初期)에는 효소활성(酵素活性)을 증대(增大)시키지만, 식물체(植物體)의 수용한계(收容限界)를 넘을 때는 오히려 효소(酵素)의 실활(失活)과 함께 식물체(植物體)가 피해(被害)를 받았다. 활엽수(闊葉樹)는 대기오염물질(大氣汚染物質)의 정화능력(淨化能力)이 큰 반면 침엽수(針葉樹)는 오염물질(汚染物質)에 대한 방어기능(防禦機能)이 크게 나타났다. 엽내(葉內) SOD 활성(活性)은 비오염지역(非汚染地域)과 오염지역간(汚染地域間)에 차이(差異)가 뚜렷하였는데, SOD 활성(活性)은 활엽수(闊葉樹)에 비하여 침엽수(針葉樹)에서 높게 나타났으며 묘목(苗木)보다는 성목(盛木)에서 높았고, 소나무보다는 잣나무에서 활성(活性)이 높았으며, 튜립나무는 은행나무와 양버듬나무보다 낮은 것으로 나타나 SOD 활성(活性)이 높은 것이 대기오염물질(大氣汚染物質)에 대한 내성(耐性)이 강(强)함을 알 수 있었다. 고유(固有)의 SOD 활성(活性)이 높은 소나무 2년생(年生)잎과 잣나무 1, 2년생(年生)잎에서는 $SO_2$ 처리농도(處理濃度)가 강(强)해질수록 SOD 활성(活性)이 증가(增加)하였으나, 고유(固有)의 SOD 활성(活性)이 나은 수종(樹種)은 저농도(低濃度(0.5ppm)처리(處理)에서는 증가(增加)하고 고농도(高濃度) 처리(處理)에서는 감소(減少)하는 경향(傾向)이었다.

• 미생물학회지
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• 제10권4호
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• pp.155-166
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• 1972

With respect to a bacterium isolated some of the similarities and differences previously indicated between Thiobacillus thiooxidans and Thiobacillus concretivorus wee confirmed and the bacteria also provided considerable diferences compared to the two species in some repects. Severe precipitation of sulfur occurred in colonies and in liquid media of the organism isolated. The organism isolated utilized nitrate and asparagine as well as ammonium sulfate as a sole nitrogen source and grew well without being nearly inhibited by citrate and malate. This organism also showed the resistance to heats and external physical stimulations. Owing to some characters decribed above and the reports proposed, the organism isolated could be concluded to be Thiobacillus concretivorus and it was suggested that Thiobacillus concretivorus might be an apparently different species from Thiobacillus thiooxidans.

• Ocean and Polar Research
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• 제22권1호
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• pp.1-13
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• 2000

Chemoautotrophic symbiotic bacteria of organisms inhabiting the hydrothermal vent and cold seep communities in the deep-sea were histologically examined using a transmission electron microscopy on symbionts of Calyptogena sp. A from the site east off Miyako (water depth at 1,700m), Calyptogena sp. B from the Calyptogena Site, vestimentiferan tube worm Lamellibrachia sp. A from Sagami Bay Lamellibrachia sp. B from Calyptogena Site of the Iheya Ridge, pogonophoran tube worms from Sagami Bay and Calyptogena Site of the Iheya Ridge, Bathymodiolus spp. from Sagami Bay, the Iheya Ridge and the North Fiji Basin. Based on the morphological microscopic observations, two species of Calyptogena from Miyako and the Iheya Ridge, two species of vestimentiferan tube worms from Sagami Bay and the Iheya Ridge, and pogonophoran tube worms from Sagami Bay and the Iheya Ridge observed to host sulfur-oxidizing symbiotic bacteria. The occurrence of chemosynthetic symbionts in these organisms was expected beforehand based on the ecological observations of their habitats. Other members of these groups from the world oceans, and the recent advances in the symbiosis at vents and seeps were reviewed.

• 천문학회지
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• 제45권6호
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• pp.157-166
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• 2012

Using the Submillimeter Array (SMA), we identified two bright hot subcores, MM1a and MM1b (size ~ 1" and mass ~ 0.5 $M_{\odot}$) separated by about 1.600, in the 230 GHz continuum emission toward the massive star-forming region DR21(OH). Both display typical hot core characteristics but have slightly different chemical properties. For example, highly saturated species show stronger emission toward MM1a and seem to be evaporating directly from the grain mantles. In contrast, simple sulfur-bearing species have brighter emission at MM1b. These features indicate that MM1a is at an earlier stage than MM1b, and the small-scale chemical differences between these two cores may result from the age difference of the order of $10^4$ years.