• 제목/요약/키워드: chemical components

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전단조건이 나일론 6/은 나노복합소재의 결정화거동에 미치는 영향 (Effect of Shearing on Crystallization Behavior of Nylon 6/Silver Nanocomposites)

  • Chae, Dong-Wook;Oh, Seong-Geun;Kim, Byoung-Chul
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2002년도 봄 학술발표회 논문집
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    • pp.321-324
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    • 2002
  • Recently, organic-inorganic nanocomposites have attracted great interest from researchers since they frequently exhibit unexpected hybrid properties synergistically derived from two components[1]. The addition of highly dispersed inorganic nano-sized fillers permits improvement of certain properties of polymers as compared with conventional particulate composites; increase of modulus and strength, improved barrier properties, increase in solvent and heat resistance, and good optical properties[2]. (omitted)

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목단의 미숙(未熟) 과실(果實)의 성분(成分)에 관한 연구 (Studies on the Chemical Constituents for the Unripe Fruits of Paeonia moutan)

  • 김영희
    • 생약학회지
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    • 제22권1호
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    • pp.22-25
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    • 1991
  • From the fresh unripe fruits of Paeonia moutan Sim. (Paeoniaceae), paeoniflorin and its acyl congeners, benzoylpaeoniflorin and benzoyloxypaeoniflorin, along with ${\beta}-sitosterol$ and methyl gallate were isolated. All compounds were identified on the basis of spectral data and chemical reactions. However, paeonol was not detected from this plant parts. These results suggested that the chemical components of the unripe fruits were virtually similar to those of root barks.

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Reuse of treated wastewater from steel industry by reverse osmosis membrane: flux decline study

  • Kwon, Tea-Ouk;Lee, Jae-Wook;Moon, Il-Shik
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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    • pp.199-202
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    • 2004
  • Membrane technology is widely employed as a means of producing various qualities of water from surface water, well water, brackish water and seawater. This is also used in industrial wastewater treatment and its recycling process. A large volume of wastewater is generated by the steel industry. Presently, the treated wastewater from the steel industry cannot be recycled, because some of its components cause either direct or indirect problems.(omitted)

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폐기가스 조성 비율이 적외선 신호에 미치는 영향 연구 (Sensitivity Study on the Infra-Red Signature of Naval Ship According to the Composition Ratio of Exhaust Plume)

  • 조용진
    • 한국산학기술학회논문지
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    • 제19권4호
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    • pp.103-110
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    • 2018
  • 함정으로부터 방사되는 적외선 신호는 주로 함정의 내연 기관에 의해 발생하는 내부적 신호와 태양열에 의해 가열된 함정 표면에서 발생하는 외부적 신호로 분류된다. 이중 내부적 신호는 주요 추진 체계를 구성하는 가스 터빈 및 디젤 엔진 폐기 가스의 화학적 조성 인자들($CO_2$, $H_2O$, CO, soot)에 의해서도 영향을 받게 된다. 따라서 본 연구에서는 현재까지 국내 함정에 탑재된 가스 터빈과 디젤 엔진에서 생성되는 폐기 가스의 화학적 조성비를 조사하여 인자와 수준을 선정하였으며, 직교 배열 실험 계획법으로 폐기 가스의 화학적 조성 인자들과 구성 비율이 함정의 적외선 신호에 미치는 영향을 연구하였다. 적외선 신호 해석 프로그램을 이용하여 계산된 폐기 가스의 적외선 신호 강도는 분석의 용이성을 높이기 위해 신호 대 잡음비로 변환하여 제시하였다. 신호 분석 결과, 가스 터빈과 디젤 엔진 모두 중적외선 대역의 신호에는 $CO_2$, soot 및 $H_2O$가 주요영향인자임이 밝혀졌다. 그리고 원적외선 대역의 신호에는 $H_2O$$CO_2$가 주요한 영향을 미치는 인자임을 확인하였다.

分子軌道論의 生物化學에의 應用 (第 2 報). 發癌物質과 DNA 鹽基와의 相互作用 (Application of Molecular Orbital Theory to Biological chemistry (II). Interactions of Chemical Carcinogens with DNA Bases)

  • 김호순;박윤열;박병각
    • 대한화학회지
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    • 제24권4호
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    • pp.280-287
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    • 1980
  • 發癌物質과 DNA 鹽基雙間의 分子錯物形成에서 可能性있는 配置(orientation)를 決定하였다. 아데닌-티민 염기쌍에서는 티민쪽에서, 구아닌-시토신 염기쌍에서는 구아닌쪽에서 分子錯物을 形成한다.

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엽배합 특성에 따른 담배 연기성분과 관능특성과의 상관관계 구명 (Study of The Relation between Smoke Component and Sensory Evaluation of Cigarettes with the Different Leaf Blending)

  • 황건중;이문수;나도영
    • 한국연초학회지
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    • 제25권2호
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    • pp.144-153
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    • 2003
  • This study was carried out to determine the relationship between smoke components and sensory evaluation by changes tobacco leaf blending. Seven different cigarettes were made by adding different types of oriental, reconstituted and expanded tobacco leaves. 62 kinds of smoke components which were 6 of general components, 34 of semi-volatile and volatile components, 9 of acid components, and 13 of phenolic components were analyzed. Eight kinds of sensory item were evaluated and also electronic nose system data was collected. All smoke components and sensory characteristics of mainstream smoke were changed by the different blending. To determine the relationship between smoke components and sensory test, the correlation and regression analysis were carried out by using SPSS statistical program. Tar, pH, and CO showed a high correlation with sensory evaluation item. As tar related to hotness, CO have a high correlation with offensive aroma. Semi-volatile and volatile components of smoke related to sensory characteristics such as aroma, taste, irritation, hotness and smoothness. When propylene, l,3-butadiene, butane, isoprene, and 2-methylfuran showed a high correlation with aroma; methyl chloride, methanol, toluene, ethyl benzene showed a high correlation with irritation. Some acidic components and phenolic components of smoke also had a high relation to smoke volume. Especially the acidic components such as 2-furoic acid, 2-hydroxybutyric acid, phenylacetic acid and palmitic acid; the phenolic components such as 4-vinyl phenol, pyrocatechol, 3-methyl catechol, hydroquinone showed a high correlation with smoke volume. As using regression analysis, it was possible to estimate the results of sensory evaluation from the smoke analysis data. From the results of electronic nose system analysis, we can find the different pattern by adding expanded tobacco leaf.

Characteristic study on the chemical components of Korean curved ginseng products

  • Cho, Chang-Won;Kim, Young-Chan;Kang, Jin-Hee;Rhee, Young Kyoung;Choi, Sang Yoon;Kim, Kyung-Tack;Lee, Young-Chul;Hong, Hee-Do
    • Journal of Ginseng Research
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    • 제37권3호
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    • pp.349-354
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    • 2013
  • Dried ginseng (DG) is in fact the representing ginseng product in the worldwide market. Although it is made in various packages depending on the processing method, size and age of DG, basic scientific data reporting the chemical components are limited. In this study, 4-year-old curved ginseng (CG), one of the domestic DG products, was selected for further investigation. Eighty-six samples of 30 and 50 piece-grade CG, which are the most widely distributed in the market, were collected for 5 yr. Their major components, such as moisture, total sugar, acidic polysaccharides, total phenolic compounds, and saponins, were analyzed to figure out the standard quality characteristics. The moisture content of all CG samples was less than 15%. The total water-soluble sugar contents were 22.9% to 47.8% and 23.2% to 49.5% in the 30 and 50 piece-grade CG, respectively. The acidic polysaccharide contents were 3.6% to 6.7% and 2.9% to 6.9% in the 30 and 50 piece-grade CG, respectively. The total phenolic compound content was 0.4% to 0.5% in CG, regardless of the piece-grade. The crude saponin content, which represents the active component of ginseng, was over 2% in all samples. In 30 piece-grade CG samples, the contents of major ginsenosides, Rb1, Rf, and Rg1, were 2.2 to 4.7 mg/g, 0.4 to 1.3 mg/g, and 1.6 to 4.0 mg/g, respectively. The ginsenoside contents in 50 piece-grade CG samples were 2.1 to 3.9 mg/g (Rb1), 0.5 to 1.2 mg/g (Rf), and 1.3 to 3.4 mg/g (Rg1). Overall, since there were relatively high standard deviation and coefficient of variation in all the chemical component contents that were assessed, we found some difficulties in showing the CG standard chemical component characteristics by average, standard deviation, and other statistical analysis factors.

Physical Properties of Carbon Prepared from a Coconut Shell by Steam Activation and Chemical Activation and the Influence of Prepared and Activated Carbon on the Delivery of Mainstream Smoke

  • Ko, Dong-Kyun;Shin, Chang-Ho;Jang, Hang-Hyun;Lee, Young-Taeg;Rhee, Moon-Soo
    • 한국연초학회지
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    • 제30권1호
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    • pp.8-13
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    • 2008
  • Several activated carbon in different specific surface area was prepared by steam and chemical activation of coconut shell. Products were characterized by BET ($N_2$) at 77K, and probed to be highly specific surface area of $1580m^2/g$ and pore volume that had increased with activating conditions. And also we have analyzed the adsorption efficiency of vapor phase components in cigarette mainstream smoke in order to evaluate the relationship between thesmoke components and the physicochemical properties of activated carbons. As a result of this study, the delivery of mainstream smoke was directly affected by the specific surface area and the pore size of activated carbon. The activated carbon prepared by steam activation exhibited better adsorption efficiency on the vapor phase components in mainstream smoke compared with activated carbon prepared by $ZnCl_2$, due to the higher micro-pore area of 66%. But the adsorption efficiency of semi-volatile matters such as phenolic components in a main stream smoke by the activated mesoporous carbon prepared by $ZnCl_2$ is more effective. From the these results, we can conclude that specific surface area by the micropore area increased the adsorption efficiency of activated carbon on vapour phase components, but semi-volatiles or particulate matter was affected by the ratio of mesopore area in total specific surface area.

Nuritive Evalution of Forage Plants Grown in South Sulawesi, Indonesia

  • Nasrullah, Nasrullah;Niimi, M.;Akashi, R.;Kawamura, O.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권5호
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    • pp.693-701
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    • 2003
  • In order to evaluate the nutritive value of the forage plants in South Sulawesi, Indonesia, 266 samples (61 grasses and 65 legumes grown in the dry season, 60 grasses and 80 legumes grown in the rainy season) were collected from the highland and lowland in 1998 to 2000, and were subjected to the determination of chemical composition and digestibility. The least-squares analysis of variance demonstrated that the in vitro dry matter digestibility (IVDMD) of grasses was not significantly affected by season or altitude. On the other hand, the some proximate components and cell wall components were significantly affected by season and altitude including the season${\times}$altitude interaction. For the legumes, the in vitro neutral detergent fiber digestibility (IVNDFD) and cellulose content were significantly affected by season. On the other hand, the ether extract (EE) content was significantly affected by season and altitude. The interaction of the season${\times}$altitude for IVDMD, of the year${\times}$season for some proximate components and of the year${\times}$season and the season${\times}$altitude for some cell wall components were significant. These results indicate that the forages grown at highland in dry season have a relatively high quality. The means of the total digestible nutrient (TDN) content estimated from IVDMD in grasses and in legumes were 50.3% and 57.4%, respectively, and the crude protein contents were 7.7% and 17.6%, respectively. The correlation coefficients between IVDMD and the contents of crude fiber, neutral detergent fiber and acid detergent fiber were relatively high in all of forage plants, suggesting that these components would provide an accurate prediction of digestibility or TDN content. A close relationship between IVNDFD and lignin content indicates that the lignin would be the most accurate predictor of cell wall digestibility.