• 한국작물학회지
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• 제33권3호
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• pp.242-247
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• 1988

향미 원료용 연초의 생육중 토양수분에 따른 잎담배의 화학성분과 품질과의 관계를 분석한 결과, 1. 토양수분이 많을수록 초장, 최대엽의 장, 폭등 개체생장이 증대되고 개화일수가 짧았으나 건조엽의 품질은 낮았다. 2 토양수분이 많을수록 생엽중 엽록소와 카로티노이드 함량이 높고, 건조엽중 니코틴, 석유에텔 유출물, 전질소함량이 낮았으며, 회분함량 및 pH는 높아졌다. 3. 토양수분이 많을수록 배휘발생 유기산과 고급지방산 함량이 높았으나 차이는 크지 않았다. 4. 토양수분이 많을수록 향미엽의 특성성분인 3-methyl pentanoic acid 등의 휘발성 유기산 함량의 감소가 컸으며 대부분의 휘발성 중성부 함량도 감소 경향이었다. 5. 토양수분이 다른 조건에서 생육한 잎담배의 품질을 비교하기 위해서는 석유에텔 추출물, 휘발성 유기산, 휘발성 중성부, 회분함량 및 pH등을 이용한 지수가 바람직하였다.

• 대한화학회지
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• 제20권1호
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• pp.59-72
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• 1976

수소화붕소아연의 선택환원성을 조사하기 위하여 대표적 유기화합물 54종을 택하여 수소화붕소 아연과 일정한 조건 (THF 용액, 실온, 수소화이온의 농도 : 0.5M, 유기화합물의 농도 : 0.125M)하에서 반응시켜 대략의 반응속도와 정량관계를 알아보았다.

• 한국작물학회지
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• 제34권1호
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• pp.40-47
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• 1989

오리엔트종 연초에서 생육 후기 조도와, 인공기상실에서의 생육 온도를 달리하여 각각 잎담배의 화학성분과 품질과의 관계를 분석한 결과, 1. 조도가 낮을수록 잎담배의 품질이 낮고, 수확엽의 엽록소함량이 높으나 단위엽면적량이 낮았으며, 2. 당, 석유에텔 추출물 및 휘발성 유기산함량이 낮고, 전질소, 니코틴, 회분, pH는 높았으며 ester 화함물은 조도가 높은 구에서 neophytadiened은 조도가 낮을수록 함량이 높았다. 3. 생육 온도가 2$0^{\circ}C$, $25^{\circ}C$, 3$0^{\circ}C$로 높을수록 개화일수가 짧고 생육이 저하되었으며, 품질은 큰 차이를 보이지 않았다. 4. 생육 온도가 높을수록 질소화합물, 회분함량, pH가 높은 당합량이 낮았으나, 석유에텔 추출물, 휘발성 유기산 및 적유성분 중성부 함량은 큰 차이가 없었다. 5. 생육중 일조와 온도가 다른 환경의 잎담배 품질평가에 공통적으로 적용이 가능한 지수로는 I-IV, IX 및 X이 추천된다.

• 한국대기환경학회지
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• 제29권6호
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• pp.722-733
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• 2013

Ground-based measurements were conducted from August 25 to September 8 of 2011 for understanding characteristics of carbonaceous aerosols measured at Gosan. Chemical components and their sources were discussed by analysis of organic compounds with identification of primary and secondary products in particulate matter. Thus, organic carbon (OC) and elemental carbon (EC) based on the carbonaceous thermal distribution (CTD), which provides detailed carbon signature characteristics relative to analytical temperature, was used to improve the carbon fractionation of the analytical method. In addition, organic compounds by gas chromatography technique with the backward trajectories were discussed for characteristics of carbonaceous aerosols. Different air-masses were classified related to the OC thermal signatures and the organic molecular markers such as aromatic acids and PAHs. We concluded that the aging process was influenced by the long-range transport from East Sea area.

• KSBB Journal
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• 제24권1호
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• pp.75-79
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• 2009

Coenzyme $Q_{10}$ 고역가 변이주인 Agrobacterium tumefaciens KPU-11-03의 다양한 유기 질소원에 대한 coenzyme $Q_{10}$ 생산량과 coenzyme $Q_{10}$의 구성비율 등을 비교한 결과, CSP 첨가 시 coenzyme $Q_{10}$ 생산량은 212.7 mg/l, 구성비율은 94%로 다른 유기질소원에 비해 매우 높게 나타났다. 특히 Bacto tryptone, Bacto peptone, soybean meal, casamino acid 등의 유기 질소원 첨가 시에는 극히 낮은 coenzyme $Q_{10}$ 역가를 나타내어 균체내의 coenzyme $Q_{10}$의 축적은 유기 질소원의 종류 즉 아미노산의 종류 및 량과 상관성이 있음을 추정할 수 있었다. 또한 무기질소원에 대하여 실험한 결과, $(NH_4)_2SO_4$ 첨가 시에 coenzyme $Q_{10}$역가가 약 2배 증가하였고 다른 무기질소원에 사용 시에는 오히려 감소하였다. Coenzyme $Q_{10}$ 역가와 관련된 아미노산을 확인하기 위해 유기질소원으로 Bacto tryptone을 첨가한 배지에 9가지의 아미노산을 첨가하여 실혐한 결과, 방향족 아미노산인 tyrosine 첨가 시의 coenzyme $Q_{10}$ 생산량은 99.5 mg/l로 비첨가구보다 약 8.2배 증가하였으나 phenylalanine과 tryptophan등의 다른 방향족 아미노산의 첨가 시에는 coenzyme $Q_{10}$ 생산량이 오히려 감소하는 것으로 나타나 tyrosine의 첨가가 coenzyme $Q_{10}$ 역가에 매우 중요함을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.896-900
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• 2000

A study was done on the synthesis of new poly(arylene ether)s and poly(arylenesulfide) with rigid benzoxazole pendants using nucleophilic aromatic substitution reaction. As a new aromatic monomer, 1,4-bis(2-benzox-azolyl)-2,5-difluorobenzene [I] w as synthesized in three steps starting from 1,4-dibromo-2,5-difluorobenzene. A model reaction of difluoro monomer [I] with two equivalents of m-cresol or thiophenol in a typical ether con-densation reaction conditions gave very high yields ( > 93%) of the desired disubstituted product, suggesting the feasibility of polymer formation in these reaction system. Monomer[I] was polymerized with bisphenols and bisbenzenethiol in NMP using K2CO3 as base. The molecular weight of the resulting polymers, however,seemed relatively low according to their solution viscosity values ( ηinh = 0.15-0.29 dL/g). The poly(arylene ether)s were soluble in several common organic solvents including chloroform, pyridine and N,N'-dimethylfor-mamide. The poly(arylene sulfide) was, however, ony soluble in strong acids like sulfuric acid and trifluoro-acetic acid. The glass transition temperatures were found to be 175-215 $^{\circ}C.$ These polymers were stable up to 380-420 $^{\circ}C$ in both nitrogen and air, as determined by the temperature that a significant weight loss began to appear on TGA.

• 한국연초학회지
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• 제10권2호
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• pp.109-116
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• 1988

Oriental tobacco (KA 101) was transplanted from Mar. 25 to May 5 with 10 days interval in 1984 and 1985, and its agronomic characteristics, chemical properties ware compared to determine the Proper transplanting time of aromatic tobacco In Korea. As the transplanting was delayed, days to flowering of plant was shortened, length and width of largest leaf, leaf area index tended to decrease. Yield was highest for the Apr. 5th transplanting followed by Mar. 25th planting, then decreased as the planting date was delayed. Quality by price decreased as the transplanting was delayed later than Apr. 25. Delaying transplanting increased nicotine, total nitrogen and ash content, but decreased reducing sugar and petroleum ether extract of cured leaves, The content of volatile organic acids such as 3-methyl pentanoic acid was lower when it was transplanted later than Apr. 25th. Neophytadiene content increased as the transplanting was delayed, but there were no trends with the content of alcohols, aldehydes esters and ketones. Several quality indices including the ratio between the content of volatile organic acids plus petroleum ether extract and ash content plus pH was higher for the Apr. 5th transplanting.

• Asian Journal of Atmospheric Environment
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• 제6권1호
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• pp.67-72
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• 2012

The chemical characterization of water-soluble organic carbon in ash emitted from a coal combustion boiler has not been reported yet. A total of 5 ash samples were collected from the outlet of an electrostatic precipitator in a commercial 500 MW coal-fired power plant, with their chemical characteristics investigated. XAD7HP resin was used to quantify the hydrophilic and hydrophobic water-soluble organic carbons (WSOC), which are the fractions of WSOC that penetrate and remain on the resin column, respectively. Calibration results indicate that the hydrophilic fraction includes aliphatic dicarboxylic acids and carbonyls (<4 carbons), amines and saccharides, while the hydrophobic fraction includes aliphatic dicarboxylic acids (>4-5 carbons), phenols, aromatic acids, cyclic acid and humic acid. The average mass of the WSOC in the ash samples was found to depend on the bituminous coal type being burned, and ranged from 163 to 259 ${\mu}g$ C/g of ash, which corresponds to 59-96 mg C of WSOC/kg of coal combusted. The WSOC mass accounted for 0.02-0.03 wt% of the used ash sample mass. Based on the flow rate of flue gas produced from the combustion of the blended coals in the 500 MW coal combustion boiler, it was estimated that the WSOC particles were emitted to the atmosphere at flow rates of 4.6-7.2 g C/hr. The results also indicated that the hydrophilic WSOC fraction in the coal burned accounted for 64-82% of the total WSOC, which was 2-4 times greater than the mass of the hydrophobic WSOC fraction.

• 분석과학
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• 제6권4호
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• pp.383-390
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• 1993

지방족 카르복실산류, 방향족화합물류 및 알킬벤젠류에 대하여 역상 HPLC에서의 용출예측 방법을 검토하였다. 용출 파라미터로서 분자 크기를 나타내는 Van der Waasls 부피와 log k'와의 상관성을 검토한 결과, 양호한 직선성을 얻을 수 있었다. 용리액의 조성을 변화시키면서 또는 분리컬럼 온도를 변화시키면서 지방족 카르복실산류, 방향족화합물류 및 알킬벤젠류에 대하여 검토한 결과, acetonitrile이 log k'와 Van der Waals 부피와의 상관성이 가장 좋았다. 본 방법을 이용하여 역상 HPLC system에서 Van der Waasls 부피가 40~250 사이의 유기화합물들의 용출을 예측할 수 있었다. 각 용매의 용출력 세기는 methanol

• Bulletin of the Korean Chemical Society
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• 제15권10호
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• pp.881-888
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• 1994

The approximate rates and stoichiometry of the reaction of excess sodium tris(diethylamino)aluminum hydride (ST-DEA) with selected organic compounds containing representative functional groups under standardized conditions(tetrahydrofuran, $0{\circ}$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of STDEA was also compared with those of the parent sodium aluminum hydride (SAH) and lithium tris(diethylamino)aluminum hydride (LTDEA). The reagent appears to be milder than LTDEA. Nevertheless, the reducing action of STDEA is very similar to that observed previously for LTDEA, as is the case of the corresponding parent sodium and lithium aluminum hydrides. STDEA shows a unique reducing characteristics. Thus, benzyl alcohol, phenol and 1-hexanol evolved hydrogen slowly, whereas 3-hexanol and 3-ethyl-3-pentanol, secondary and tertiary alcohols, were essentially inert to STDEA. Primary amine, such as n-hexylamine, evolved only 1 equivalent of hydrogen slowly. On the other hand, thiols examined were absolutely stable. STDEA reduced aidehydes and ketones rapidly to the corresponding alcohols. The stereoselectivity in the reduction of cyclic ketones by STDEA was similar to that by LTDEA. Quinones, such as p-benzoquinone and anthraquinone, were reduced to the corresponding 1,4-dihydroxycyclohexadienes without evolution of hydrogen. Carboxylic acids and anhydrides were reduced very slowly, whereas acid chlorides were reduced to the corresponding alcohols readily. Esters and epoxides were also reduced readily. Primary carboxamides consumed hydrides for reduction slowly with concurrent hydrogen evolution, but tertiary amides were readily reduced to the corresponding tertiary amines. The rate of reduction of aromatic nitriles was much faster than that of aliphatic nitriles. Nitrogen compounds examined were also reduced slowly. Finally, disulfide, sulfoxide, sulfone, and cyclohexyl tosylate were readily reduced without evolution of hydrogen. In addition to that, the reagent appears to be an excellent partial reducing agent: like LTDEA, STDEA converted ester and primary carboxamides to the corresponding aldehydes in good yields. Furthermore, the reagent reduced aromatic nitriles to the corresponding aldehydes chemoselectively in the presence of aliphatic nitriles. Consequently, STDEA can replace LTDEA effectively, with a higher selectivity, in most organic reductions.