• 한국식품과학회지
• /
• 제33권3호
• /
• pp.366-372
• /
• 2001

Aspergillus oryzae균을 파종하여 만든 누룩으로 담금한 탁주 술덧의 발효과정 중 휘발성 향기성분을 GC와 GC-MS를 사용하여 분석 동정한 결과 ester 24종, alcohol 21종, acid 10종, aldehyde 9종, 기타 4종 등 68종의 향기 성분이 동정되었다. 동정된 향기성분 수는 담금일에 ester 13종, alcohol 12종을 비롯한 총 36종이었으나, 발효 2일에 ester 10종, alcohol 8종을 포함한 29종이 추가 검출되어 65종으로 증가되었다. 발효 12일에는 68종으로 향기 성분수가 최대에 달하였다. ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol, benzeneethanol등 alcohol류 12종, ethyl acetate, ethyl caprylate, ethyl butyrate 등 ester류 13종, acetaldehyde, isobutyl aldehyde등 aldehyde 4종, pentanoic acid , acetic acid등 acid 6종 등 총 35종은 발효 전과정을 통하여 검출되었다. 향기 성분의 면적비율은 ethanol이 $79.86{\sim}89.54%$로 발효 전기간을 통하여 탁주 술덧에서 타 성분 보다 월등히 높았다. ethanol을 제외하고 발효 전과정을 통하여 면적비율이 높은 성분은 ethyl caprylate, 3-methyl-1-butanol, benzeneethanol이었다. 이외 발효기간에 따라서 2-methyl-1-propanol, 1-hexanol, 2,3-butanediol(D.L), 1-dodecanol, 2-phenylethyl acetate, ethyl acetate, monoethyl butanoate, diethyl succinate, ethylbenzoic acid, acetic acid, isobutylaldehyde등의 성분도 동종 계열간의 향기 성분중 면적비율이 다소 높게 나타나기도 하였다.

• 한국식품과학회지
• /
• 제37권6호
• /
• pp.944-950
• /
• 2005

Asp. kawachii균을 파종하여 만든 누룩으로 담금 한 탁주 술덧의 발효과정 중 휘발성 향기성분을 GC와 GC/MS를 사용하여 분석 동정한 결과 ester 22종, alcohol 20종. acid 10종, aldehyde 8종, 기타 3종 등 63종의 향기 성분이 동정되었다. 동정된 향기성분 수는 담금 일에 ester 13종, alcohol 13종을 비롯한 총 32종이었으나, 발효 2일에 ester 6종, alcohol 3종을 포함한 13종이 추가 검출되어 45종으로 증가되었다. 발효 12일에는 63종으로 향기 성분수가 최대에 달하였다. Ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol, benzeneethanol등 alcohol류 12종, ethyl acetate, ethyl caprylate, ethyl butyrate 등 ester류 12종, acetaldehyde, iso-butyl aldehyde등 aldehyde 3종, octanoic acid, 1,2-benzenedicarboxylic acid 등 acid 2종, 총 29종은 발효 전 과정을 통하여 검출되었다. 향기 성분의 면적비율은 ethanol이 72.18-91.32%로 발효 전 기간을 통하여 탁주 술덧에서 타 성분보다 월등히 높았다. Ethanol을 제외하고 발효 전 과정을 통하여 면적비율이 높은 성분은 ethyl caprylate, 3-methyl-1-butanol, benzeneethanol 이었다. 이외 발효기간에 따라서 2-methyl-1-propanol, 1-hexanol, 2, 3-butanediol(D.L), 1-dodecanol, 2-phenylethyl acetate, ethyl acetate, monoethyl butanoate, diethyl succinate, ethylbenzoic acid, acetic acid, iso-butylaldehyde 등의 성분도 동종 계열간의 향기성분 중 면적비율이 다소 높게 나타나기도 하였다.

• 한국식품저장유통학회:학술대회논문집
• /
• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
• /
• pp.149.2-149
• /
• 2003

비조사 김치와 2.5, 5 및 10 kGy로 방사선 조사된 김치로부터 SDE 방법으로 추출한 휘발성 유기화합물을 분석하여 변화를 확인하였다. 김치의 주요 휘발성 유기화합물로 ethyl formate, ethyl acetate, ethanol, dimethyl disulfide, methyl 2-propenyl disulfide가 다량 함유되어 있었고, ethyl methyl disulfide, 4-cyano-1-butene, pentane dinitrile 등도 상당량 함유되어 있었다. Ethyl formate, ethyl acetate, ethanol은 조사선량이 증가함에 따라 상당량 증가하는 것으로 확인되었으며, dimethyl disulfide, ethyl methyl disulfide, methyl propyl disulfide, pentane dinitrile, S-methyl methyl thiosulfonate 등도 선량이 증가함에 따라 함량이 증가하였다. 1-Penten-3-ol은 조사선량에 따라 감소하였다.

• 약학회지
• /
• 제33권4호
• /
• pp.237-240
• /
• 1989

A new synthetic method for tiaprofenic acid, which is a potent anti-inflammatory agent, was described. Friedel-Crafts reaction of thiophene with ethyl ${\alpha}-chloro-{\alpha}-(methylthio)$ acetate (1) gave ethyl ${\alpha}-methylthio-2-thiopheneacetate$ (3). Ethyl ${\alpha}-methyl-2-thiopheneacetate$ (5) was prepared by treatment of (3) with NaH and MeI, followed by desulfurization with zinc dust-acetic acid of the resultant ethyl ${\alpha}-methyl-{\alpha}-methylthio-2-thiopheneacetate$ (4). Tiaprofenic acid (7) could be easily synthesized by benzoylation of (5) and hydrolysis of the resultant ethyl $5-benzoyl-{\alpha}-methyl-2-thiopheneacetate$ (6).

• 한국환경과학회지
• /
• 제32권6호
• /
• pp.403-417
• /
• 2023

In this study, we investigated the characteristics of Volatile Organic Compounds(VOCs) emission from painting and printing facilities in the Pyeongdong industrial complex in Gwangju. In addition, the objective was to understand the distribution characteristics of VOCs in the ambient air in industrial complexes affected by painting and printing facilities. The painting facility mainly emitted toluene, acetone, butyl acetate, 4-methyl-2-pentanone, ethyl acetate, 1-butanol, methyl ethyl ketone, m,p-xylene, o-xylene, 4-ethyltoluene, ethylbenzene, 3-ethyltoluene, and 1,2,4-trimethylbenzene. The main emission components in printing facilities were methyl ketone, ethyl acetate, acetone, 2-propanol, toluene, heptane, and butyl acetate. Ethyl acetate, toluene, 2-butanone, acetone, butyl acetate, 2-propanol, xylenes, and 4-methyl-2-pentanone were detected in the ambient air of the Pyeongdong industrial complex, consistent with the VOCs emitted by painting and printing facilities. The average concentration of seasonal TVOCs followed an order of winter > fall > spring > summer, whereas the concentrations of daytime and nighttime TVOCs were generally higher at night than those during the day, and the wind speed was greater during the day than it was at night. Based on a factor analysis of VOCs in the ambient air of Pyeongdong industrial complex, it is considered that organic solvents used in coating, printing, and electronics manufacturing facilities, as well as diesel vehicle emissions played a major role.

• 대한화학회지
• /
• 제27권6호
• /
• pp.441-448
• /
• 1983

여러가지 브롬화비닐 화합물들 ((Z)-1-bromopropene, 1-bromo-2-methylpropene, 2-bromo-3-methyl-2-butene, (E)-ethyl 2-methyl-3-bromo-2-propenoate, 1-bromo-cyclohexene)과 올레핀 화합물인 ethyl acrylate, methyl methacrylate, ethyl crotonate, allyl cyanide, ethyl 3-butenoate, ethyl 4-pentenoate와 methyl 10-undecenoate를 palladium acetate촉매와 triorthotolyphosphine 및 triehylamine존재 하의 수득율로 얻었으며 이들 생성물의 입체화학도 규명하였다. 위의 방법을 이용하므로써 ethyl 3-butenoate, ethyl 4-pentenoate와 methyl 10-undecenoate에 의한 4개, 5개 및 11개 탄소-탄소 결합의 확장도 가능하였다.

• 한국응용과학기술학회지
• /
• 제2권2호
• /
• pp.31-38
• /
• 1985

The transesterification reaction between ethanolamine and methyl-methacrylate was kinetically investigated in the presence of various metal acetate catalysts at $110^{\circ}C$. The transesterification was found to obey first-order kinetice with respect to the concentration of ethanolamine and methyl-methacrylate, respectively. By the Arrhenius plot, the activation energy has been calculated as 11.9 Kcal with lead acetate catalyst, 14.7 Kcal without catalyst. The reactivities has highest value where the electronegativity and instability constant (Kij) values for the metal acetate catalysts are about 1.6.

• 접착 및 계면
• /
• 제13권2호
• /
• pp.64-72
• /
• 2012

비닐아세테이트와 알킬아크릴레이트계 에멀젼공중합에서 개시제인 ammonium persulfate (APS)의 농도, 보호 콜로이드인 poly(vinyl alcohol) (PVA)의 종류와 농도, 공단량체인 methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (BA)의 혼합비를 변화시켜 중합하였다. 제조된 poly(vinyl acetate-co-methyl acrylate) (PVAc/PMA), poly(vinyl acetate-co-ethyl acrylate) (PVAc/PEA), poly(vinyl acetate-co-n-butyl acrylate) (PVAc/PBA)에 대하여 다음과 같은 결론을 얻었다. 등온 열분해법으로 $100{\sim}200^{\circ}C$ 영역에서 구한 비닐아세테이트와 알킬아크릴레이트 공중합체에 대한 등온 열분해 활성화에너지는 PVAc/PMA > PVAc/PEA > PVAc/PBA이었으며, 플라스마 처리 전과 후의 접착박리강도는 PVAc/PMA > PVAc/PEA > PVAc/PBA의 순이었다.

• 한국환경과학회지
• /
• 제23권6호
• /
• pp.1151-1156
• /
• 2014

The photocatalytic decomposition characteristics of single n-pentane, n-pentane mixed with methyl ethyl ketone (MEK), and n-pentane mixed with ethyl acetate (EA) by cylindrical UV reactor installed with $TiO_2$-coated perforated plane were studied. The effects of the residence time, the inlet gas concentration, and the oxygen concentration were investigated. The removal efficiency of n-pentane was increased with increasing the residence time and the oxygen concentration, but decreased with increasing the inlet concentration of n-pentane. The photocatalytic decomposition rates of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA fitted well on Langmuir-Hinshelwood kinetics equation. The maximum elimination capacities of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA were obtained to be $465g/m^3{\cdot}day$, $217g/m^3{\cdot}day$, and $320g/m^3{\cdot}day$, respectively. The presence of coexisting MEK and EA vapor had a negative effect on the photocatalytic decomposition of n-pentane and the negative effect of MEK was higher than that of EA.

• Advances in Energy Research
• /
• 제4권4호
• /
• pp.325-337
• /
• 2016

Cerbera Odollam (sea mango) is a proven promising feedstock for the production of biodiesel due to its high oil content. Fatty acid methyl esters (FAME) were produced as the final reaction product in the transesterification reflux condensation reaction of sea mango oil and methyl acetate (MA). Potassium methoxide was used as catalyst to study its reacting potential as a homogeneous base catalyst. The initial part of this project studied the optimum conditions to extract crude sea mango oil. It was found that the content of sea mango sea mango oil was 55%. This optimum amount was obtained by using 18 g of grinded sea mango seeds in 250 ml hexane. The extraction was carried out for 24 hours using solvent extraction method. Response surface methodology (RSM) was employed to determine the optimum conditions of the reaction. The three manipulated variables in this reaction were the reaction time, oil to solvent molar ratio, and catalyst wt%. The optimum condition for this reaction determined was 5 hours reaction time, 0.28 wt% of catalyst and 1:35 mol/mol of oil: solvent molar ratio. A series of test were conducted on the final FAME product of this study, namely the FTIR test, GC-FID, calorimeter bomb and viscometer test.