• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1697-1698
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• 2002

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.924-928
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• 2005

We synthesized the two types of photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the two types of photopolymer surface can be obtained. The Voltage-transmittance (V-T) curve in the photoaligned TN cell with UV exposure was different from two type. The response time of photoaligned TN cell was measured about 21 ms in two alkyl chain and about 15 ms in four alkyl chain.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.279-282
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• 1998

This expriment was carried out to get basic information on composition and yield of aromatic constituents in leaves of four medicinal plants, Angelica tenuissima, Chrysanthemum zawadskii. ssp. latilobum, Artemisia iwayomogi and Artemisia capillaris. Volatile aromatic constituents, 28 compounds in Angelica tenuissima were identified and 19 compounds were indentified in Chrysanthemum zawadskii ssp. latilobum. Volatile aromatic constituents, 23 compounds in Artemisia iwayomogi and Artemisia capillaris were identified. Major volatile aromatic consitiuents analyzed by GC/MS in four plants were $\alpha$-pinene, camphene, sabinene, cis-2-hexanol, and camphor etc. Content of essential oils in Angelica tenuissima, Chrysanthemum zawadskii ssp. latilobum, Artemisia iwayomogi and Artemisia capillaris were 0.014, 0.275, 0.785, and 0.452%, respectively. As a result, it was suggested that a medicinal plant, Artemisia iwayomogi, was worthy of using as a useful material of perfume.

• Journal of the Korean Chemical Society
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• v.38 no.10
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• pp.726-733
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• 1994

Supercritical fluid extraction (SFE) followed by gas chromatographic separation and mass spectrometric (MS) detection were used in rapid analysis of polycyclic aromatic hydrocarbons (PAH's) in air particulate material extracted for 30 min with 10 ml of supercritical $N_2O$ without another sample preparation step. Two samples, urban dust in Seoul area and a certified air particulate reference material 1649 supplied by the NBS (National Bureau of Standards), were processed for the purpose of evaluating extraction and analysis methods. As a result, the quantitative recovery of PAH's in the SFE method was relatively lower than conventional organic solvent extraction methods, but reproducibility was resonable, and analysis time was reduced remarkably. The method has proved to be suitable for monitoring of PAH's in air particulate material.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.50-55
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• 2016

Aromatic diamines containing hexafluoroisopropylidene and ester moiety were synthesized from 4,4'-hexafluoroisopropylidene diphenol and nitrobenzoyl chloride. The reaction of aromatic diamines with hexafluoroisopropylidene phthalicdianhydride (6FDA) or pyromellitic dianhydride (PMDA) gave four kinds of poly(amic acid)s. Their inherent viscosities ranged from 0.196 to 0.346 dL/g. Poly(amic acid)s were converted to polyimides by thermal imidization. The glass transition temperatures ($T_g$) of polyimides were between 241 and $289^{\circ}C$. The 5% weight loss temperatures were recorded in the range of $430{\sim}492^{\circ}C$. The tensile strength of polyimide films were measured as 29.84~64.38 MPa.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.333-339
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• 2008

Korean ginseng (Panax ginseng C. A. Meyer) has been used as an important medicinal plant in the Orient for a long time. It has been claimed that ginseng has many beneficial bioactive effects on human health, such as antitumor, antistress, antiaging and enhancing immune functions. Red ginseng possibly have new ingredients converted during steaming and dry process from fresh ginseng. Kujeungkupo method which means 9 repetitive steaming and drying process was used for the processes of green tea, Polygonatum odoratum, and Rehmanniae radix preparata. In this study, ingredient conversion of ginseng by 9 repetitive steaming and drying process were investigated measuring conversion efficiency of brown materials, crude lipids, crude proteins and aromatic compounds. Brown materials, as an antioxidant, in red ginseng were produced through non-enzymatic reaction by heat. Repetitive steaming and drying treatments on ginseng root contiunously increased the content of brown materials and the chromaticity. Crude lipids were degraded by heat and converted into volatile aromatic ingredients. Crude lipids were degraded and decreased by 0.52% after the 5th and 7th. Crude proteins were also decomposed and converted to amino acid. Crude proteins after the 9th treatment were decreased by more than 85% as increased times of treatments. A bicyclogermacrene as aromatic material was decreased as increased treatment times, while but a aromatic caramel was increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.185-188
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• 2005

We synthesized the two types of photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the two types of photopolymer surface can be obtained. The Voltage-transmittance (V-T) curve in the photoaligned TN cell with UV exposure was different from two type. The response time of photoaligned TN cell was measured about 21 ms in two alkyl chain and about 15ms in four alkyl chain.

• Journal of the Korean Applied Science and Technology
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• v.19 no.4
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• pp.302-310
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• 2002

Demand for organic analysis increase as industries are growing and many products are spreaded in the daily life. One of many products is oil spill dispersant. It was used for oil accident in the ocean. When oil spill dispersant spread at the ocean, the petroleum in the ocean is dispersed. The oil spill dispersant is made of non ionic surfactant and petroleum oil. The non ionic surfactant disperse petroleum from oil accident. The other part is petroleum oil which has aromatic hydrocarbon. Because the aromatic hydrocarbon is cancerogenic material, it directly injure animals in the ocean. This cause the second pollution in the human body. Many oil accidents still are controlled by oil spill dispersant. Therefore quality control of the oil spill dispersant become important and this also demand for the exact quantitative analysis of aromatic hydrocarbon. Hereupon the first we develop separate petroleum oil from surfactant. The second standardize analytical method of aromatic hydrocarbon in the separated petroleum oil.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.432-434
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• 2006

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.47-54
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• 1983

Tobacco leaves cultivated in Korea, U.S A., Greece and Turkey were analyzed for their essential oils that are solanone, nor- solanadione, damascenone, dana scone and mesa stigmatrienone (4- isomer). Regardless of tobacco varieties and cultivated localities, solanone was the most abundant. Among them particularly, Basma has the highest amounts of the solanone than other varieties. Flue-cured tobacco leaf has much higher amounts of damascellone than burley and aromatic tobacco leaf do. U.S. A. flue-cured, U.S. A. burley and Basma clave much higher concentration of solanone than corresponding Korean varieties, but significant differences could not be observed in other components. The order of total amounts of 8 essential oils in tobacco varieties were as follows; Aromatic) Burley) Flue-cured