• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.45-56
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• 2003

In this study the distribution patterns of the metallic components were analyzed both before and after the Asian Dust (AD) events at 2001 by comparing the chemical composition of metallic components in terms of various statistical methods. According to the AD/NAD concentration ratio of metallic components, the main components of crustal soils were exhibiting the values above 1.0; but opposite results were seen dominantly for hazardous metallic components. Examination of fine-to-coarse (F/C) ratios of metallic components showed higher values for major anthropogenic components including Pb (5.83). Ni (2.61), etc. Comparison of our measurement data with those obtained within and across the Korean peninsula indicated that the metallic distribution patterns of the study area can be distinguished from previous studies. The results of our analysis, when investigated in relation with air mass movement patterns. indicated evidence of the direct influence of AD events and anthropogenic processes.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.742-758
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• 2005

Lipid-based functional components present in foods undergo chemical changes during cooking. Useful n-3 and n-6 fatty acids, phytosterols, tocopherols, and carotenoids are degraded by thermal cooking such as frying, resulting in loss of their physiological functions. However, conjugated linoleic acid and diacylglycerols can be formed during heating, which would be beneficial to the health. Degree of degradation and formation of the functional components depends on the cooking method, cooking temperature and time, lipid matrix containing the components, and the presence of other materials. Although it is clear that the content of each functional component varies during long-heating in a model system consisting of small numbers of components, the real foods cooked in a small scale for a limited cooking time do not show highly significant differences in the functional components contents from raw food materials.

• Mycobiology
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• v.41 no.1
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• pp.47-55
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• 2013

Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination between biocontrol agents and chemical inducers recorded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in field.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.389-415
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• 1996

Panax ginseng C.A. Meyer(Araliaceae) has been traditionally used as an expensive and precious medicine in oriental countries for more than 5, 000 years. Ginseng saponin isolated from the root of Panax ginseng have been regarded as the main effective components responsible for the pharmacological and biological activities. Such as antiaging effects. antidiabetic effects anticancer effects. Protection against physical and chemical stress. Analgesic and antipyretic effects. Effects on the central nervous system, tranquilizing action and others. Thirty kinds of ginsenosides have been so far isolated from ginseng saponin and their chemical structures have been elucidated since 1960's. Among which protopanaxadiol type is 19 kinds. protopanaxatriol type. 10 kinds and oleanane type, one. Since ginsenosides are generally labile under acidic conditions ordinary acid hydrolysis is always accompanied by many side reactions, such as epimerization. hydroxylation and cyclization of side chain of the sapogenins Especially. it is well known that C-20 glycosyl linkage of ginsenoside was hydrolysed on heating with acetic acid to give an equilibrated mixture of 20(S) and 20(R) epimers. And also, the chemical transformations of the secondary metabolites have appeared during the steaming process to prepare red ginseng. Indicating demalonylation of malonyl ginsenosides, elimination of glycosyl residue at C-20 and isomerization of hydroxyl configuration at C-20. But these studies have not provided a comprehensive picture in explaning how these ginsenosides showed val'iotas pharmacological activities of ginseng. Though some of them have been involved in the mechanism of pharmacological actions. Recently, non-saponin components have received a great deal of attention for their antioxidant, anticancer antidiabetic, immunomodulating. anticomplementary activities and so on. To meet the demand for such wide applications, studies on the non-saponin components play an important role in providing a good evidence of pharmacological and biol ogical activities. Among the non-saponin constituents of Korean ginseng, polyacetylenes, phenols. Sesquiterpenes, alkaloids. polysaccharides oligosaccharides, oligopeptides and aminoglycosides together with ginsenosides of terrestrial part are mainly described.

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.14-22
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• 2021

The objective of this study was to investigate the effect of alkali-washing with different sodium hydroxide concentrations on the chemical compositions of steam-treated Betung bamboo strand. Strands were subjected to steam treatment at 126 ℃ for 1 h under 0.14 MPa pressure and followed by washing with 1-5% sodium hydroxide solution for 30 sec. The alteration of structural and non-structural chemical components content of bamboo strands was evaluated. Steam and washing treatments with various concentrations of sodium hydroxide solution considerably reduced the extractive content of bamboo strands, and the cell wall chemical components of the strand in the small degree. FTIR analysis showed noticeable changes in peaks related to hemicellulose and lignin. The relative crystallinity increased significantly after steam and washing treatment with sodium hydroxide up to 3% concentration. SEM Images showed smooth and clean strands surface after washing with 3% sodium hydroxide.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.1
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• pp.65-71
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• 1987

In order to obtain the most suitable ageing term of Flue-cured tobacco in natural condition, leaf tobacco packed in hogshead and stored in leaf tobacco warehouse for 4 years, and the changes of major physico-chemical components were examined at three months intervals, As storage time goes by, except the moisture content, general chemical components of leaf tobacco were decreased until about 9-15 months of storage. Among them, decrement of total sugar was the most significant. After 18 months storage, the chlorophyll was decreased by 50% of initial stage. The content of essential oils, solanone, damascenone, megastigmatrienone I, II, III, IV, were approached the maximum between 12 months and 15 months of storage and then lessened by degrees.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.22.3-22.3
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• 2008

We present the results of the investigations of high dispersion spectra of two stars. These are the eclipsing binary RR Lyn, and $\rho$ Pup - the prototype of the group of pulsating variables. The spectra were obtained at 1.8 m Bohyuunsan observatory telescope, and 8.2 m VLT. We found the chemical composition. The both components of RR Lyn are Am stars (metallic line stars), but the abundance patterns of the components are not similar - the iron abundance and the abundances of other elements are surely different. For few elements the differences exceeds 1 dex. We found the abundances of 56 chemical elements in the atmosphere of $\rho$ Pup. This is one of the best stellar abundance patterns. It permits to investigate the role of the charge-exchange reactions in stellar atmospheres. These reactions can produce the abundance anomalies in the atmospheres of B-F type stars. These reactions can be one of the sources of galactic cosmic rays, and the reason of the braked rotation of A-F type chemically peculiar stars.

• Journal of Ginseng Research
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• v.16 no.1
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• pp.1-6
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• 1992

Chemical composition was determined to evaluate the quality of Panel ginseng-leaf tea over green teas. Ginseng-leaf tea was shown to contain higher contents of soluble matter, ascorbic acid and lower contents of tannins, as compared to tea leaves. The profiles of ginsenoside and sugar of ginseng-leaf tea were noticeably different from those of ginseng roots and the sample maintained high levels of these components under the manufacturing process. Total unsaturated fatty acids and free amino acids were estimated to be decreased in ginseng-leaf tea as compared to those of ginseng leaves. The compositions of amino acids and minerals in ginseng-leaf tea were similar to those of tea leaves and glutamic acid, aspartic acid, leucine, calcium, potassium, sodium, and copper were found to be major components.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.106-114
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• 1980

The flavor constituents of Korean Milgam were extracted with a nitrogen gas stream under partial vacuum and identified by gas liquid chromatography. By employing the extraction coefficient, it was possible to determine the concentration of components in Milgam as well as in the extracts. Among 53 GLC peaks, 26 components were identified. Ethanol was the most abundant component (140ppm), followed by limonene (120ppm). These two were the most important flavor constituents.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.103-111
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• 2017

Purpose: Accelerated degradation tests can speed time to market and reduce the test time and costs associated with long term reliability tests to verify the required service life of a product or material. This paper proposes a service life prediction method for components or materials using an accelerated degradation tests based on the relationships between temperature and the rate of failure-causing chemical reaction. Methods: The relationship between performance degradation and the rate of a failure-causing chemical reaction is assumed and least square estimation is used to estimate model parameters from the degradation model. Results: Methods of obtaining acceleration factors and predicting service life using the degradation model are presented and a numerical example is provided. Conclusion: Service life prediction of a component or material is possible at an early stage of the degradation test by using the proposed method.