• Journal of the Korean Chemical Society
• /
• v.14 no.3
• /
• pp.277-279
• /
• 1970

• Journal of Korean Society of Steel Construction
• /
• v.15 no.2
• /
• pp.147-157
• /
• 2003

The application in steel structures is increasing the mill sheet for the weathering steels by minimum maintenance cost in a life cycle cost. These have been collected and statistically analyzed to investigate chemical compositions, mechanical properties, weldability indices, weathering index and impact absorbed energy. From this study, although the band of dispersion in chernical compositions, mechanical properties and impact absorbed energy of the weathering steels appeared a little larger, the results revealed that these values have adequately satisfied the standard values of the Korean Standard. Furthermore, it was found that the weldability indices and the weathering index for the weathering steels have respectively satisfied the value prescribed by the Japanese Highway Specification and ASTM.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2002.10a
• /
• pp.161-161
• /
• 2002

최근, 무분별한 농약사용으로 인해 조리 후에도 잔류하는 농약성분의 독성이 문제시 되고 있어 인체 내로의 섭취 전에 독성 유무와 그 정도를 확인할 수 있는 방법 개발을 위한 연구가 활발히 진행되고 있다. 본 연구에서는 채소류, 곡류, 과일류 등에 빈번히 사용되는 농약성분의 독성 확인과 함께 이들 식품 내에 잔류하는 농약성분의 검출을 위한 방법을 연구하였으며, 이들의 독성 유무를 유전자 재조합된 5종의 발광성 미생물을 이용하여 확인하였다. 또한 이들 농약류가 식품 내에 잔류하여 발생하는 독성을 분석하기 위해 식품내 잔류하는 농약 성분의 추출에 필요한 효율적인 추출 용매를 제작하였으며, 농약성분의 화학적 성질에 따라 추출 방법을 두 단계로 분리하여 추출률을 향상시켰다. 뿐만 아니라, 식품류의 특성에 적합하게 식품별로 특정한 추출방법을 연구하였으며, 추출된 농약 성분의 독성 및 안정성 역시 발광성 박테리아를 이용하여 확인하여, 전체적인 추출방법의 효율을 진단하였다.

• The Journal of Korean Institute for Practical Engineering Education
• /
• v.4 no.2
• /
• pp.84-90
• /
• 2012

It is described that the total analysis of CD-R, a digital recording media, including the planning and performing chemical analysis of cross sectional structure of recording layer, dye composition and chemical structure as an example of design for chemical analysis. Since chemical analysis of unknown sample is often involved the complicated process requiring many experiences and knowledge, students feel difficulties in planning the procedure of chemical analysis and selecting analytical methods. Thus, an example of chemical analysis is provided here to help student understanding the hole procedure of CD-R analysis. In this study, SEM is used to determine the cross sectional structure of PC substrate and recoding layer of CD-R. The dyes in recording layer is dissolved with solvent and separated with using TLC, analyzed with using UV-Vis absorption spectrometer. Then, the chemical structure of each component is determined with using GC-MS, NMR and mass spectrometer.

• Journal of Adhesion and Interface
• /
• v.25 no.2
• /
• pp.63-68
• /
• 2024

In this study, the contamination of gold(Au) wire according to the types of rinse applied for surface treatment in the wire bonding process is investigated and confirmed. For the surface treatment, rinses containing silicon(Si) or those based on organic materials are mainly employed. To identify their effects, surface treatment is conducted on Au wire using two types of rinse at a 1.0 wt% concentration, referred to as Si-including and Oil-based rinse-coated Au wire. Subsequently, a simulation experiment is performed to verify the reactivity of dust containing Si components that could occur in the semiconductor process. Through optical microscopy (OM) and scanning electron microscopy(SEM) analysis, it is observed that a larger amount of dust is adsorbed on the surface of Si-including rinse-coated Au wire compared with the Oil-based rinse-coated Au wire. This is attributed that the rinse containing Si components is relatively polar, causing polar interactions with dust, which also has polarity. Therefore, it is expected that using a rinse without Si components can reduce contamination caused by dust, thereby decreasing the defect rate in the practical wire bonding process.

• Korean Journal of Medicinal Crop Science
• /
• v.12 no.6
• /
• pp.459-462
• /
• 2004

Essential oil components were analysed in forty seven individual plants of Elsholtzia splendens collected from eight different regions in Korea to identify their chemotypes. Major oil components of chemotype 1 was dihydrotagentone (75%) and naginataketone and elsholtziaketone were not detected at all. Chemotype 2 was naginataketone (NK) type which content was more than 60%. Chemotype 3 had more than 60% of elsholtziaketone (EK) as major volatile oil. EK type and NK type plants selected were maintained stably in their progenies after seed generation. Naginatketone and elsholtziaketone had functional properties such as antioxidation and antibacteria.

• The Korean Journal of Ecology
• /
• v.24 no.3
• /
• pp.137-140
• /
• 2001

The antifungal activity of chemical substances from Artemisia annua were examined. Antifungal activity of aqueous extracts from A. annua was higher than that of essential oils in Fusarium oxysporum, whereas that of essential oil was higher than that of aqueous extracts in Aspergillus nidulans. The GC/MS methods were employed for the analysis and identification of phytotoxic substances from A. annua. Essential oil of some components were identified including thujone, terpineol, β-pinene, cienole, 2,4-hexndienal, camphor, citronellal, (-)-menthone, (1R)-(-)myrtenol, (S)-(-)-perilla aldehyde, perilla alcohol, 4-tert-buthylaniline, eugenol, isosafrole, isoeugenol and α-humulene. These results suggest that the chemical substances from A. annua such as terphenoids seem to be responsible for the allelopathic effect.

• Proceedings of the Korean Journal of Food and Nutrition Conference
• /
• 2000.12a
• /
• pp.53-53
• /
• 2000

최근 복분자(산딸기)의 효능을 이용한 일반식품 및 기능성 식품 등의 제품 개발이 활발히 추진되고 있다. 따라서 본 연구에서는 식품차원의 연구분야 일환으로서 먼저 복분자의 일반성분, 유리당, 유리아미노산, 무기성분 및 향기성분 등을 보고한 후 앞으로 생리 활성 연구 분야에 초점을 두고 연구를 진행할 하여 학문적 자료 및 산업에 응용할시 기초자료로 활용하고자 한다. 복분자의 수분은 5.39%, 총당은 17.3%, 환원당은 8.6%, 조단백질 10.6%, 조회분은 4.5%, 조지방은1.7%, 조섬유는 3.9%이고, 유리당 함량은 sucrose 1.52%, fructose 3.98%, glucose 1.24%이고, 유기산 함량은 citric acid 10.2%, oxalic acid 6.29%로 가장 많이 함유하고 있었고, 그 다음은 malic acid 1.94%였다. 총 아미노산은 7914.1mg%이고, 필수아미노산 함량은 2622.5mg%로 나타났다. 복분자에 가장 많이 함유되어 있는 아미노산은 aspartic acid 1260.3%, 그 다음은 glutamic acid 1054.3% 순으로 함유하고 있었다. 무기성분 K가 387mg으로 가장 많이 함유되어 있었고, 복분자에서 총 52종의 성분이 화인되었는데 확인된 성분들은 관능기별로 분류하면 amylalcohol를 포함한 alcohol류 11종, valeric acid를 포함한 acid류 13종, hexanal를 포함한 carbonyl류 20종, 2-heptanone를 포함한 hydrocabon류 5종 그리고 methyl palmitate를 포함한 ester류가 3종 이었다. 관능기별로 확인된 성분들의 총 peak area%를 살펴보면 alcohol류 11.56%, acid류 38.87%, hydrocarbon류 2.89%, ester류 0.80%, 총 70.32%가 확인되었다. Alcohol류에서 linalool가 3.78%, acid류에서는 caproic acid류가 14.40%, carbonyl류에서 2-hydroxy-4-methoxyacetophenone이 2.99%, hydrocabon류에서는 aromadendrene가1.59% 그리고 ester류에서는 methyl palmitate가 0.43%으로 가장 많이 함유하고 있었다.

• Korean Journal of Plant Resources
• /
• v.30 no.2
• /
• pp.240-264
• /
• 2017

The present study was carried out to identify traditional konwledges on Korean Campanulaceae plants and conduct a comprehensive review of them through analyzing phytochemistry and pharmacology of Korean Campanulaceae plants. According to the literature study, the ethnobotanical plants of Korean Campanulacae consisted of a total 18 taxa. Of them, 12 taxa including Platycodon grandiflorus, Adenophora triphylla var. japonica, Codonopsis lanceolata and others have been used as ethnomedicinal plants. These plants have been used for the treatment of 49 diseases such as cold, asthma and postnatal care. Phytochemical studies have identified the constituents present from Korean Campanulaceae (Adenophora, Codonopsis, Platycodon, Campanula and Asyneuma). A wide range of chemical compounds comprised 109 triterpenes, 8 sterols, 4 polyacetylenes, 21 alkaloids, 14 flavonoids, 14 phenolic acids, 11 phenolic glycosides, 8 phenylpropanoids and 22 other compounds. Pharmacological studies of these compounds have demonstrated immuno-stimulating, anti-inflammatory, anti-asthmatic, apophlegmatic and anti-allergic effects. They have also shown antioxidant, estrogenic, anti-diabetic, hepatoprotective, neuroprotective, antinociception and anti-tumor activities, as well as anti-obesity and cardiovascular effects. In light of traditional knowledge and phytochemical and pharmacological studies summarized, uses of Korean Campanulaceae based on traditional knowledge (for the treatment diseases and conditions of respiratory, pregnancy, childbirth, puerperium, genitourinary, circulatory, musculoskeletal and other systems) have been supported by phytochemical and pharmacological studies.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.5
• /
• pp.581-585
• /
• 1993

Five flavonoids isolated from the ethyl acetate fraction of Cedrela sinensis A. Juss. were identified by high performance liquid chromatography. Separation was achieved by reversed phase chromatography on ${\mu}-bondapak$ C18 column with isocratic elution method. The content of the major flavonoid, quercitrin was about 9.48%(w/w) and 37.06%(w/w) for the methanol extract and ethyl acetate fraction, respectively.