• International Journal of Automotive Technology
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• 제7권4호
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• pp.501-508
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• 2006

The effect of chemical additives, such as dimethyl ether(DME), ethanol, carbon disulfide on the soot formation were examined numerically. ill this study, the Frenklach soot mechanism was used as a base mechanism to predict the soot formation in the ethane flame. The combination of Westbrook's DME mechanism, Marinov's ethanol mechanism, and chemical kinetic mechanism for hydrogen sulfide and carbon disulfide flames was made with the base mechanism because the DME, ethanol, $CS_2$ additives are added into the ethane fuel. CHEMKIN code was used as a numerical analysis software to simulate the effect of chemical additives on reduction of the polycyclic aromatic hydrocarbons(PAH's) which are soot precursors. From the numerical results it is observed that addition of DME, ethanol and $CS_2$ into ethane fuel can reduce PAH species significantly. That means theses additives can reduce soot formation significantly. Results also strongly suggest suppression of soot formation by these additives to be mainly a chemical effect. Hand OH radicals may be the key species to the reduction of PAH species for additives.

• 한국식품영양과학회지
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• 제27권4호
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• pp.563-567
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• 1998

Volatile flavor components of edible portion of leek(Allium tuberosum R.) were extracted by SDE(simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethylether (1 : 1, v/v) as an extract solvent and analyzed by GC-FID and GC/MS. Identification of the volatile flavor components was mostly based on the RI of GC and mass spectrum of GC/MS. A total of sixty-five components from leek extract were classified as 28 sulfur-containing compounds, 12 aldehydes, 9 alcohols, 4 lactones and esters, 3 acids and hydrocarbons, and 2 miscellaneous compouds. The sulfur-containing compounds were predominant in leek extract. Dimethyl disulfide(19.47%) and dimethyl trisulfide(17.38%) were the main compounds and trans-1-propenyl methyl disulfide, trans-2-hexenal and methyl allyl disulfide were also detected large amounts in leek.

• 한국응용과학기술학회지
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• 제24권3호
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• pp.296-300
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• 2007

This paper presents applicability of photocatalytic decomposition of methyl mercaptan using $TiO_2$. A quartz reactor was used in order to elucidate reaction pathway in photocatalytic decomposition of methyl mercaptan. Experimental results showed that more than 99.9% of methyl mercaptan was decomposed within 30 minutes. It was found that the photocatalytic decomposition of methyl mercaptan followed pseudo first order and its reaction coefficient was $0.05min^{-1}$ During 30 minutes in the photocatalytic reaction, the concentration of methyl mercaptan, dimethyl disulfide, $SO_2$, $H_2SO_4$, COS, $H_2S$ were determined. These results showed that 64% of methyl mercaptan were compensated for the increase in sulfur after 30 minutes through the mineralization. The proposed main photocatalytic decomposition pathway of methyl mercaptan was methyl $mercaptan{\rightarrow}dimethyl$ $disulfide{\rightarrow}SO_2{\rightarrow}H_2SO_4$.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E3호
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• pp.153-163
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• 2002

A laboratory- scale dual-column biofilter system was used to study the biofiltration of dimethyl disulfide (DMDS). The gas flow rate and DMDS concentration to the biofilter were varied to study their effect on the remov-al of dimethyl disulfide. Operating parameters such as pH, temperature, and water content were monitored during the biofilter operation and necessary precautions were taken to keep these parameters within the acceptable limits. It was observed that the removal efficiency of DMDS was optimal at neutral pH values. After five month op-eration, the neutralization of the filter beds with sodium carbonate became necessary for the optimum operation of the biofilters. The microbial population already present in the compost mixtures was found to be adequate in treat-ing DMDS. The compost mixtures were found to be similar in terms of biofiltration efficiency of DMDS. However, pressure drops observed in the first column compost mixture (compost/ peat mulch) was extremely high, making this compost economically not feasible. The second mixture (compost/bark) provided pressure drops within accept-able limits. A minimum residence time of 30 seconds at the optimal operating conditions appeared to be adequate for achieving high removal efficiencies (>90%).

• 미생물학회지
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• 제40권2호
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• pp.127-132
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• 2004

활성 오니법에 의한 하수처리장 포기조에서 슬러지를 채취하여 황화물계 악취제거 균주인 Thiobacillus속의 선별 배지로 50개 균주를 분리하였다. 분리한 50개 균주의 동정 결과 7개 균주는 Thiobaecillus neapolitanus, 4개 균주는 Thiobacillus tepidarius, 5개 균주는 Thiobacillus denitrificans, 23개 균주는 Thiobacillus versutus, 2개 균주는 Thiobacillus intetmedius, 9개 균주는 Thiobacillus perometabolis로 동정되었다. 분리 동정한 균주들로 고효율 황화물계 악취(황화수소, dimethyl sulfide, methyl disulfide)제거 균주 스크린을 하였다. 그 결과 황화수소, dimethyl sulfide에 대하여 KT5l(Thiobacillus versutus)균주가 각각 l00％, 85％로 가장 높은 제거율을 보였다. Dimethyl disulfide의 경우에는 전체 균주가 다른 악취성분에 비해 제거율이 낮았는데 KT8l균주가 26％로 가장 높은 제거율을 보였다. 스크린 결과 KT5l균주를 선별하였으며, 선별된 KT51균주를 밀폐된 모형 생물학적 처리 반응기에 적용하여 황 화합물의 제거 효율을 비교한 결과, 황화수소의 경우, 100 ppm을 주입 후 균주 적용전의 운전 결과는 30분 이후에 0.02 ppm 미만(99.8％)으로 제거한 반면, 균주 적용 시의 운전 결과는 15분에 황화수소를 0.02 ppm 미만(99.8％)으로 처리하였다.

• 한국식품영양과학회지
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• 제34권2호
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• pp.230-235
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• 2005

SDE추출방법과 GC/MS 분석에 의하여 동결건조한 양파의 휘발성 유기정분변화를 비교 분석하였다 생양파와 동결건조양파에서 각각40와31종의 화합물이 확인되었으며, 이들은 ester류, aldehyde류, ketone류, alcohol류, 함황화합물류이었다. 함황화함물류들이 생양파와 동결건조 양파에서 주요 화합물로 가장 많은 함량을 차지하였고, 이 중 1-propanethiol과 dipropyl trisulfide, methyl propyl tirsulfide, dimethyl trisulfide는 생양파와 동결건조 양파에서 모두 다량 확인되었다. 생 양파에서 주요 성분으로 확인되었던 1-propanethiol, dipropyl trisulfide는 동결건조 양파에서 매우 감소되었고, methyl propyl trisulfide, methyl propyl disulfide 역시 같은 경향을 보였다. Methyl allyl sulfide, propyl ally sulfide, dially disulfide그리고 3,5-diethyl-1,2,4-trithiolane등의 함황화합물과 propanol, pentanol, hexanol 등의 alcohol류 등은 생양파에서 확인되었으나 동결건조 양파에서 확인되지 않았다. 이러한 결과를 통하여 양파의 건조과정 중 특징적인 휘발성 유기성분의 구성변화와 특성의 손실 그리고 효소 불활정화로 인한 휘발성 성분의 불완전한 생성 등을 알 수 있었다. 또한 동결건조 양파에서 ethyl acetate, dimethyl disulfide와 2-methyl-2-pentenal은 생 양파에서보다 그 함량이 증가되었고, (Z)-propenyl methyl disulfide와 (E)-propenyl methyl disulfide 또한 동결건조 양파에서 증가되어 짐을 확인하였다.

• 한국식품과학회지
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• 제54권2호
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• pp.126-133
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• 2022

본 연구에서는 달래의 특징적인 향 특성을 확인하기 위해 봄에 수확한 노지 재배 달래와 시설 재배 달래를 SAFE법으로 추출하고 GC-MS-O를 통해 휘발성 향기성분을 분석하였다. 달래는 알데하이드류와 황 함유 화합물의 함량이 높았으며, 휘발성 성분으로는 2-methyl-2-pentenal, 2-methyl-2-butenal 및 (E)-1-propenyl propyl trisulfide의 함량이 높았다. 달래의 향 특성에 기여하는 주요한 향 활성 화합물은 2-methyl-2-pentenal, (Z)-1-propenyl methyl disulfide, dipropyl disulfide, dimethyl trisulfide, (E)-1-propenyl propyl disulfide, dipropyl trisulfide, (E)-1-propenyl propyl trisulfide, 2-isopropyl-3-methoxypyrazine 및 2-sec-butyl-3-methoxypyrazine으로 총 9종이 확인되었다. 2-Isopropyl-3-methoxypyrazine와 2-sec-butyl-3-methoxypyrazine은 달래의 흙 냄새에 기여하는 화합물로 가장 강한 향 강도를 보였다. Dipropyl disulfide, dimethyl trisulfide 및 dipropyl trisulfide는 달래의 양파 및 마늘과 같은 향 특성에 기여하는 화합물로 향 강도가 피라진류 다음으로 강했고, 노지 재배 달래에서 시설 재배 달래보다 더 강하게 감지되었다. 2-Methyl-2-pentenal, (Z)-1-propenyl methyl disulfide 및 (E)-1-propenyl propyl disulfide는 달래에서 자른 양파와 같은 매운 향 특성에 기여하는 화합물로 노지 재배 달래에서 더 높은 함량과 강도를 보였다. (E)-1-Propenyl propyl trisulfide 와 (E)-1-propenyl methyl disulfide은 절인 야채 및 양배추 냄새에 기여하는 화합물로서 노지 재배 달래에서 낮은 함량과 향 강도를 보였다.

• 한국환경과학회지
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• 제16권1호
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• pp.33-38
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• 2007

The concentrations of offensive odorous compounds emitted from the two chemical plants in Chongju and Yeosu industrial complex in Korea were determined by uv/vis spectroscopy, gas chromatography, and high performance liquid chromatography. The odorous compounds examined in this study are ammonia, trimethyl amine, formaldehyde, acetaldehyde, propion aldehyde, butyl aldehyde, n-valeric aldehyde, iso-valeric aldehyde, hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide. The concentrations of those were determined from the 10 sampling points of the two plants, respectively. The emission concentrations of all odorous com-pounds examined in the two plants were lower than those of the regulation standard levels of industrial complex in Korea, respectively. The propion aldehyde, n-valeric aldehyde, methyl mercaptan and dimethyl disulfide in Chongju and Yeosu plants, and butyl aldehyde and iso-valeric aldehyde in Yeosu plant were not detected at any sampling points examined.

• 한국식품위생안전성학회지
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• 제15권3호
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• pp.235-240
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• 2000

식품의 항균물질 분리에 있어 여러 가지 방법이 있지만 오차와 손실이 많아 실용화 하기에는 많은 문제점이 있다. 현재 일반적인 분리법으로 유기용매분획법, 크로마토그래피 등이 있으나, 많은 시간과 노력을 필요로 하며 시료에 따라 항균활성이 소실되는 경우가 많다. 본 연구는 전편의 '부추의 미생물학적 항균활성 특성과 가공식품에의 응용'에 이어 부추의 항균활성 물질을 효과적으로 분리하기 위한 방법을 정립하고 항균활성 물질을 확인하였다. 부추의 항균활성 물질 분리를 위하여 ultrafiltration, liquid-liquid extraction, TLC, HPLC 순으로 정제하였다. Ultrafiltration 결과 항균물질은 분자량 5,000 dalton 이하의 저분자 물질이었고, TLC로 분리된 8개의 spot중 대조군에 비하여 높은 항균활성을 나타내는 1개의 spot을 추출하여, HPLC로 유효 peak 2개를 얻었고 각 peak성분을 GC/MS로 확인한 결과 cis-propenyl methyl disulfide, 5-methyl methylthiosulphonate, dimethyl disulfide등의 황화합물로 구성된 복합물질로 확인되었다.

• 동아시아식생활학회지
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• 제16권3호
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• pp.299-307
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• 2006

Raw whole garlic was pickled in two different ways, in soy sauce and in brine, to test the change of flavor compounds with aging period. The changes of pH, acidity, hardness and flavors were measured, accompanied with sensory evaluation. The pH of whole garlic in soy sauce and in brine was decreased as the aging period increased. The acidity was increased as pH decreased. Hardness tended to decrease as the aging time increased. For whole garlic in soy sauce and in brine, trans propenyl methyl disulfide, allyl methyl trisulfide, diallyl trisulfide, dimethyl trisulfide, allyl- 2,3-epoxypropyl sulfide, and 2-methyl-l,3-dithiane were increased as the aging proceeded but allyl methyl disulfide and diallyl disulfide tended to decrease. Hardness through the sensory evaluation decreased as the aging time increased. When the overall quality was compared between whole garlic in soy sauce and in brine after 60 days, the latter could be better estimated. Pickled garlic increased the flavor compounds such as trans propenyl methyl disulfide, allyl methyl trisulfide, diallyl trisulfide, dimethyl trisulfide, allyl-2,3-epoxypropyl sulfide, and 2-methyl-l,3-dithiane as the aging proceeded. Therefore, the above flavor compounds are considered as the major ingredients of the characterized flavor of pickled garlic.