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        검색결과 118

        22.
        2009.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Semi-automatic cryogenic-preconcentrator is constructed with time controlling function in preconcentration and desorption stage. GC-FPD and cryogenic-preconcentrator were to analyze gaseous sulfur compounds (hydrogen sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide) in ppbv level. The objective of this study was to offer reliable methods for sulfur gas analysis in all procedures (keeping, concentration, desorption, and detection). The cryo-concentrator was able to concentrate 4 L gas sample of 40 % relative humidity. The recovery rate of the system was in the range of 92~100 % at 30 seconds of pre-heating time, and method detection limits were shown up 0.16~0.20 ng which is able to quantify 1 ppbv level with 0.5 L gas sample. The storage time of 5 ppbv sample in polyethylene bag led to serious loss (e.g; H₂S: loss of 30% after storage 3 days). It was estimated that the analytical bias was affected more sensitively by storage time after sampling than by cryo-injection procedures in the analysis of hydrogen sulfide and methanethiol.
        4,000원
        23.
        2004.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This paper describes to evaluate the performance of ventilation as a change of CO2 concentration with ventilation rate under 35 occupants in a school classroom. Variations of the CO2 concentration as a function of time are measured at center point of classroom with air ventilation rates by the CO2 gas monitor. For 800 m3/h of ventilation rate in the classroom, the average CO2 concentration is 913 ppm. The ventilation rate is sufficient to meet acceptable indoor air quality (≤ 1,000 ppm of CO2, KS school standard) in the classroom of 35 students.
        4,000원
        24.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        5,800원
        35.
        2018.10 서비스 종료(열람 제한)
        Background : Miscanthus sinensis is a C4 crop with high photosynthetic efficiency and is known as a representative cellulose-based bio-energy crop originating in East Asia such as Korea, Japan, and China. It also has a high resistance to environmental conditions such as low temperature and drying and pests. However, many studies on the antioxidant activity of the M. sinensis have not been conducted. Therefore, this study was conducted to measure total phenol and total flavonoid contents of the M. sinensis accessions collected from some countries and to select the M. sinensis accessions with rich total phenol and total flavonoid contents. The results of this study can be used as basic data for future breeding. Methods and Results : This study carried out the total phenol and total flavonoid contents analysis of M. sinensis collected from different country to preserve genetic resources. Total 205 accessions of M. sinensis were collected from the USA, China, Korea, Japan, Thailand and Zambia. Their leaves were extracted with 100% methanol and concentrated at 45℃. To determine total phenol and total flavonoid contents, we measured the total phenolic content and total flavonoid content. The highest total phenolic conten t(81.04 ± 0.02 ㎎·GAE/g) showed in the accession (PMS-178) from China. The highest total flavonoid content (32.66 ± 0.01 ㎎·QE/g) showed in the accession (KMS104) from Korea. On the other hand the lowest total phenolic content (1.11 ± 0.00 ㎎·GAE/g) and the total flavonoid content (0.81 ± 0.00 ㎎·QE/g) were obtained from the accession (M. sinensis ‘Super Stripe’) from USA. Conclusion : In this study, we analysed the total phenolic and total flavonoid contents by country of origin.
        36.
        2018.10 서비스 종료(열람 제한)
        Background : Miscanthus is a species of flowering plant in the family poaceae, native to Eastern Asia throughout most of China, Japan, Taiwan and Korea. It is diploid hybrid grass used as bioenergy plant, biomass production and high quality of cellulose and ethanol production. It is an herbaceous perennial grass, growing up to 0.8 - 3.0 m tall, rarely 4.0 m, forming dense clumps from an underground rhizome. Recently, Studies on Miscanthus have been carried out on the growth characteristics and to see the antioxidant difference of Miscanthus for functional materials in various regions. Methods and Results : This study carried out the antioxidant activities of Miscanthus collected from different countries of origin. Two hundred one accessions of Miscanthus were collected in 7 countries (China, Japan, Korea, Taiwan, Thailand, U.S.A, Zambia). Initially, each leaves were extracted with 70% ethanol to determine actioxidant activty. Antioxidant activities were evaluated by DPPH and ABTS radical scavenging activity. The highest DPPH radical scavenging activity showed in the accession [M. sinensis ‘Kleine Silberspinne (little silver spider)’] from U.S.A (RC50: 10.66 ± 15.46 ㎍/㎖) and the lowest showed in the accession (M. sinensis ‘Supr Stripe’) from U.S.A (RC50: 188.03 ± 0.86 ㎍/㎖). The ABTS radical scavenging activity showed the highest in the accession (No.401: JM0310.002) from Japan (RC50: 17.97 ± 3.26 ㎍/㎖) and the lowest showed in the accession (M. sinensis ‘Supr Stripe’) from U.S.A (RC50: 416.88 ± 10.05 ㎍/㎖). Conclusion : The antioxidant activity of Miscanthus showed in average DPPH radical scavenging activity (RC50: 74.05 ± 3.74 ㎍/㎖) and ABTS radical scavenging activity (RC50: 81.46 ± 3.95 ㎍/㎖). In this study, it may be used for feed crops or food crops as a functional material.
        37.
        2018.10 서비스 종료(열람 제한)
        Background : The isoflavonoids, triterpene and polysaccharides were know as major components in Astragalus membranaceus Bunge. Especially, isoflavonoids are classified as ononin, calycosin-glucoside of glycon binding and formononetin, calycosin of aglycone binding. In this study, we performed fermentation by a lot of microorganisms which were derived foods. Methods and Results : The A. membranaceus was extracted with 50% Ethanol and it was concentrated using rotary evaporator. In order to change in isoflavonoids, we fermented the A. membranaceus extracts with microorganisms which have β-glucosidase activity. we chose 20 microorganisms using esculin agar method and three strains with the highest activity of β -glucosidase were identified by pNP assay. The extracts of A. membranaceus were fermented during 3 days in sterilized distilled water, as 1 Brix and 3 Brix. The isoflavonoids of fermented extract, respectively days 0, 1, 2 and 3, were analyzed using High Pressure Liquid Chromatography (HPLC). In addition, the fermented A. membranaceus extracts was investigated about whitening effect using tyrosinase and radical scavenging activity by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). As a result of β-glucosidase activity by pNP assay, we selected two strains, Pediococcus pentosaceus (KACC 81017BP), Saccharomyces cerevisiae (KACC 83014BP). On the third day of fermentation of S. cerevisiae, isoflavone aglycone was the highest. The calycosin-glucoside and ononin in fermented A. membranaceus extract were reduced, calycosin and formononetin was increased compared to control. Also, we confirmed higher activity than control in tyrosinase inhibition rate on the third day of fermentation, as 78.38% and lower IC50 value of radical scavenging activity as 584.68 ㎍/㎖. Conclusion : From the above results, we may suggest that A. membranaceus aboveground parts might have useful as a safe material for functional food and pharmaceutics.
        38.
        2018.10 서비스 종료(열람 제한)
        Background : In this study, we investigated the formation of Abeliophyllum distichum callus which has not been reported until now and the culture optimization. The potential of callus cultures was examined by comparing the components and antioxidant activities of callus and wild planting. Furthermore, it was intended to provide data on the possibility of substitution for the active ingredient production of Abeliophyllum distichum callus extraction. Methods and Results : We tried to induce callus by introducing it in vitro culture by using leaves and stem of Abeliophyllum distichum grown in Goesan Chungbuk. In order to investigate the effect of growth regulators on the callus, TDZ, NAA, 2,4-D, IBA and BAP were treated with 0.25 to 5 ㎎/ℓ of single hormone, and the combination hormones were treated with two concentrations of BAP (0.1, 1.0 ㎎/ℓ) and 2,4-D, NAA, IBA at 0.1 ㎎/ℓ and 1.0 ㎎/ℓ. And investigate the effect of inorganic salt concentration on somatic embryogenesis, the incidence of callus was examined by culturing 1X, 1/2X MS medium for 4 weeks. As a result, the effect of growth regulator and treatment concentration on the callus formation of Abeliophyllum distichum, callus induction was the fastest in the 2,4-D condition, but the callus indection was slow. The highest amount was produced ine the NAA condition. The axillary bud was best grown in TDZ condition, but no root was formed. LC chromatogram was able to compare the contents of leaf, stem extracts and callus extracts. Antioxidant ativity showed excellent antioxidative activity in the extracts of the wild planted stem. Conclusion : The optimum culture conditions for callus were 1/2X MS, 1 ㎎/ℓ BAP and 0.1 ㎎/ℓ of 2,4-D. As a result of LC chromatogram, it was confirmed that callus extract contained a large amount of the same components as the stem and leaf extracts grown on the wild planting. Currently, Studies on mass culture using bioreactor to utilize this are underway, We could confirm the potential possibility of Abeliophyllum distichum cultured products.
        39.
        2018.08 KCI 등재 서비스 종료(열람 제한)
        Background: The objective of this study was to investigate the effect of packaging material on the growth of rootstock of Liriope platyphylla. Methods and Results: This study examined the effects of two types of packaging material, LDPE (low density polyethylene) and functional film on the growth of the tubers of L. platyphylla, at 5℃. During the 16-weeks of storage period, the ratio of loss and decay of the tubers was examined at intervals of 4, 8, and 16 weeks to detect the quality of the plant. After 16 weeks of storage, the treated tubers were own. Subsequently, plant height and the number of leaves were recorded. The results revealed that functional film at 5℃ was the ideal material for the storage of L. platyphylla tubers. The rate of loss was the highest (57.42%) with a onion net and the lowest (22.12%) with a functional film. Similarly, the rate of tuber decay was highest (8.20%) using onion net and the least (4.60%) when the functional film was used. Conclusions: Thus, the use of the functional film proved to be the most effective in the storage of L. platyphylla tubers when compared with the LDPE.
        40.
        2018.05 서비스 종료(열람 제한)
        Background : Panax ginseng C. A. Meyer is a medicinal plant corresponding to 'raw materials for food use' in Korean food standards codex, and it is known that it has the same origin although it is classified into wild ginseng, cultured ginseng and red ginseng. It varies morphologically, molecularly, depending on the cultivation or habitat environment. In this study, we carried out experiments for the morphological differentiation of cultured ginseng (Hongcheon, Gunsan, Miryang) and adventitious roots culture of wild mountain ginseng (by company). Methods and Results : Morphological observations were made with resin sectioning method (RSM). The test method was sampled, preprocessed, embedded, segmented, slid and then observed with an optical microscope. The epidermis, cortex and vascular tissues were identified in the inner cross section of adventitious roots culture of wild mountain ginseng. Phloem was formed at the center, and xylem was formed at the side. In cultured ginseng, the organs of the vascular tissues were differentiated into two, whereas in the adventitious roots culture of wild mountain ginseng, one vascular tissue was formed due to the thin adventitious. Conclusion : Plant resources have the diversity of using the same or different origins depending on their distribution. The morphological differentiation method of ginseng and adventitious roots culture of wild mountain ginseng is expected to be based on domestic fair trade to prevent discrimination.
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