• Journal of the Korean Wood Science and Technology
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• 제12권2호
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• pp.27-34
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• 1984

In order to investigate the acidic chlorinated compounds in pulp bleaching spent liquor, the lignin model compounds, coniferyl alcohol(mp $74^{\circ}C$), ${\omega}$-(2-methoxyphenoxy)-acetoguaiacone(mp $93^{\circ}C$) and dehydrodiisoeugenol(mp $133^{\circ}C$), were synthesized and chlorinated by chlorine in glacial acetic acid. From the chlorinated products, the following chlorine-containing aromatic compounds were identified by TLC. In coniferyl alcohol the chlorine-substituted compounds at 4-, 5-and 4,5-position of aromatic nucleus were identified and in ${\beta}$-0-4 type the compounds substituted chlorine for alkyl group and/or hydrogen at land 1,4-position of aromatic nucleus expected to be formed by electrophilic displacement from ${\omega}$-(2-methoxyphenoxy)-acetoguaiacone were not identified but the chlorine-substituted compounds at 4-, 5-, 6- and 5,6-position of aromatic nucleus were identified.

• Macromolecular Research
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• 제11권2호
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• pp.92-97
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• 2003

Model compounds and polymers having N-substituted 1,2-diphenylmaleimide moieties were synthesized and characterized by NMR, IR, UV, and fluorescence spectroscopy. The fluorescence intensity could be controlled by N-substituents of model compounds and polymers. As the structure of an N-substituent of them was bulkier, or the electron density of an N-substituent was denser, the photoluminescence intensity was increased. All the compounds showed greenish yellow photoluminescence with the maximum intensity between 510 and 537 nm. From quantum efficiency data of the model compounds and the polymers, the fluorescence intensity of the polymer 11 was higher than that of the model compound 4.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.88-91
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• 1999

Aroma components of tea processed from Korean chicory roots were isolated and identified. The model system of amino-carbonyl reaction was carried out to study the formation mechanism of aroma compounds of chicory tea during manufacturing process. The concentration extracts from chicory tea and model system were analyzed and identified by gas chromatography(GC) and GC-mass spectrometry. Twenty-nine compounds, including pyrazines, furans, acids, alcohols, pyrroles and lactones were isolated and identified in chicory tea. The main compounds were pyrazines including methyl pyrazine, 2,5-dimethyl pyrazine, 2, 6-dimethyl pyrazine, 2-ethyl-6-methyl pyrazine, 2-ethyl-3-methyl pyrazine, thrimethyl pyrazine, 3-ethyl-2-5-dimenthyl pyrazine, 5-ethyl-2-3-dimenthyl pyrazine, and 2-acetyl-3-methy pyrazine and pyrroles including acethl pyrrole and formlyl pyrrole ; and furans including furfural , acetyl furan, 5-methyl furan, 5-methyl furfuralm, and furfuryl alcohol. These pyrazine compounds of a roasted and nutty aroma may be important contributors to the flavor of chicory tea. The aroma concentrate of model system also had a roasted and nutty aroma and the main compounds were methyl pyrazine, 2, 5-dimetyl pyrazine, 2, 6-dimethyl pyrazine and trimethyl pyrazine.

• 상하수도학회지
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• 제18권2호
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• pp.165-173
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• 2004

Behavior of hazardous organic compounds including bisphenol A, phtalic acid, and phosphoric acid in low pressure nanofiltration process were investigated. In the case of NTR729HF, rejection of all target organic compounds except 2-H-Benzothiazol and 2-isopropyl phenol was more than 90%. The lowest rejection for 2-H-Benzothiazol was observed in another membranes. The UTC60 and UTC20 showed similar rejection characteristics of hazardous organic compounds. Although the rejection of Bisphenol A, n-buthyl benzenesulfoneamide, N-ethyl-p-toluensulfonamide, 2-H-benzothiazol, p-t-butylphenol and 2-isopropyl phenol was less than 30%, the rejection of tributyl phosphate, triethyl phosphate, camphor, 2,2,4 trimethyl 1,3 pentandiol and diphenyl amine was more than 90% in the case of UTC60 and UTC20. The rejection characteristics of various hazardous organic compounds were converted into one parameter Ks, which was proposed in the diffusion-convection model. The Ks of hazardous organic compounds were discussed by comparing with their solute size represented by Stokes radius. The diffusion convection model considering Ks was successful to interpret rejection characteristics of hazardous organic compounds by low-pressure nanofiltration membranes.

• 멤브레인
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• 제10권4호
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• pp.186-191
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• 2000

Ethyl esters (aroma model compounds; ethyl acetate, ethyl propionate, ethyl butyrate) 수용액으로부터 aroma 화합물의 회수를 위해, 표면 개질한 알루미나막을 이용하여 증기 투과를 수행하였다. Ethyl butyrate의 구동력이 가장 큼에도 불구하고, 투과부에서 ethyl ester의 농도는 ethyl butyrate가 가장 높았으며, ethyl propionate, acetate의 순서로 나타났다. 또한, 물에 대한 ester 화합물의 용해도가 상당히 낮기 때문에 투과부에서 상분리가 일어나 순수한 aroma 화합물을 얻을 수 있었다. 실험 결과, 제조된 소수성 알루미나막은 에스테르 화합물에 대해 높은 선택도와 투과 플럭스를 보여 주었다.

• Natural Product Sciences
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• 제17권4호
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• pp.309-314
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• 2011

Synthetic coumarin and furocoumarin derivatives were evaluated for anticoagulant activity and the effect on liver and kidney function. It was found that all of the compounds under investigation proved to be neither toxic nor lethal up to 500 mg/100 g body weight as a single dose for 24 hrs. All tested compounds showed a significant increase in prothrombin time (PT) in the acute model but failed to show a significant action in the chronic model. Furthermore, all tested compounds revealed a significant increase in activated partial thromboplastin time (APTT) as compared to control value in both acute and chronic model. Also, all tested compounds did not cause any significant changes on liver and kidney functions in rats.

• 한국환경과학회지
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• 제11권12호
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• pp.1321-1326
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• 2002

A numerical model is investigated to predict a behavior of the gaseous volatile organic compounds and a subsurface contamination caused by them in the unsaturated zone. Two dimensional advective-dispersion equation caused by a density difference and two dimensional diffusion equation are computed by a finite difference method in the numerical model. A laboratory experiment is also carried out to compare the results of the numerical model. The dimensions of the experimental plume are 1.2m in length, 0.5m in height, and 0.05m in thickness. In comparing the result of 2 methods used in the numerical model with the one of the experiment respectively, the one of the advective-dispersion equation shows better than the one the diffusion equation.

• 분석과학
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• 제28권4호
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• pp.270-277
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• 2015

비등점은 유기물의 물리화학적 성질을 특정하는데 있어 매우 근본적 요소 중 하나이다. 그러나 기존의 정량적 구조-물성 상관관계식들은 고에너지 물질 등과 같은 특정 물질 군에 대한 실험값들의 부족 등으로 인해 제한적인 응용성을 가지고 있었다. 본 연구에서는 서로 다른 출처로부터의 5,923개의 비등점 자료를 확보하였으며, 이에는 일반적 유기화합물과 더불어 특수목적을 가지는 분자들을 포함하였고, 이들 수집된 데이터 셋을 이용하여 새로운 비등점 예측모델을 개발하는데 사용하였다. 다양한 학습 방법을 이용하여 새로이 수집된 데이터 셋을 이용한 2차원 분자 표현자에 기반한 비등점 모델을 도출하였다. 개발된 예측모델의 적정성과 견고성을 확인하였고, 훈련 셋의 표현자에 기반한 비등점 예측모델의 적용구역을 도출하였다.

• Elastomers and Composites
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• 제41권4호
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• pp.223-230
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• 2006

고무복합체는 높은 점탄성 성질을 보이는데 압출성형 시 이 점탄성 성질 때문에 압출물이 팽창하게 된다. 그리고 팽윤양은 공정 조건에 따라서 변한다. 점탄성 성질에서 탄성 부분은 압출물의 팽창에 있어서 중요한 역할을 한다. 본 논문은 모세관 다이에서 여러 가지 고무복합체에 따른 다이팽윤을 알아보기 위해 상용 CFD 프로그램인 Polyflow를 사용하여 해석을 수행하였다. 컴퓨터 모사에서는 비선형 미분 점탄성 모델인 Phan-Thien-Tanner(PTT) 모델을 사용하였고 온도를 고러하여 해석하였다. 해석을 통해서 레저버와 모세관 다이에서 압출물의 압력, 속도, 그리고 온도 분포 등을 예측하였다. 여러 가지 고무 복합체의 다이 팽윤양을 알아보기 위해서 유량과 모세관 다이의 지름을 변경하면서 연구하였다. 본 연구를 통해서 PPT 모델은 고무 복합체에 대한 점탄성 거동을 잘 표현하고 있음을 확인할 수 있었다.

• 한국안전학회지
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• 제36권1호
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• pp.1-8
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• 2021

To simulate a process model in the field of chemical engineering, it is very important to identify the physical properties of novel materials as well as existing materials. However, it is difficult to measure the physical properties throughout a set of experiments due to the potential risk and cost. To address this, this study aims to develop a property prediction model based on the group contribution method for aromatic chemical compounds including benzene rings. The benzene rings of aromatic materials have a significant impact on their physical properties. To establish the prediction model, 42 important functional groups that determine the physical properties are considered, and the total numbers of functional groups on 147 aromatic chemical compounds are counted to prepare a dataset. Support vector regression is employed to prepare a prediction model to handle sparse and high-dimensional data. To verify the efficacy of this study, the results of this study are compared with those of previous studies. Despite the different datasets in the previous studies, the comparison indicated the enhanced performance in this study. Moreover, there are few reports on predicting the physical properties of aromatic compounds. This study can provide an effective method to estimate the physical properties of unknown chemical compounds and contribute toward reducing the experimental efforts for measuring physical properties.