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        검색결과 273

        185.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        생장조절물질과 광도가 국화 경정배양에 미치는 영향 을 조사하였다. 다신초(multiple shoots) 형성은 국화 경 정을 MS배지에 kinetin 2.0mg · L-1와 NAA 0.2mg · L-1 첨가된 배지에 배양하였을 때 촉진되었으며, 형성된 다 신초는 MS배지에 kinetin 2.0mg · L-1와 NAA 0.02 mg · L-1 첨가된 배지에 배양하였을 때 생육이 촉진되었 다. 한편, 국화 경정을 NAA 0.2mg·L-1와 BA 1.0mg · L- 1가 첨가된 배지에 배양하였을 경우에는 절편체당 신초 형성 수가 6.9개로 가장 많았으나 형성된 신초의 대부분 이 유리질화 되었다. 기내에서 국화묘의 생장은 광도 100 μmol · m-2 · s-1 PPFD에서 신초의 길이와 엽록소 함량이 가장 높았다.
        4,000원
        192.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon molecular sieve (CMS) membranes were prepared by pyrolysis of polyimides having carboxylic acid groups and applied to the hydrogen separation. The polymeric membranes having carboxylic acid groups showed different steric properties as compared with polymeric membranes having other side groups (-CH3 and -CF3) because of the hydrogen bond between the carboxylic acid groups. However, the microporous CMS membranes were significantly affected by the decomposable side groups evidenced from the wide angle X-rat diffraction, nitrogen adsorption isotherms, and single gas permeation measurement. Furthermore, the gas separation properties of the CMS membranes were essentially affected by the pyrolysis temperature. As a result, the CMS membranes Prepared by Pyrolysis of polyimide containing carboxylic acid froups at 700℃ showed the H2 permeability of 3,809 Baller [1×10-10 H cm(STP)cm/cm2.s.cmHg], H2/N2, selectivity of 46 and H2/CH4 selectivity of 130 while the CMS membranes derived from polyimide showed the H2 permeability of 3,272 Barrer, H2/N2 selectivity of 136 and H2/CH4 selectivity of 177.
        4,000원
        193.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The functional Jeungpyuns with dietary fiber containing cereals such as brown rice and barley flour were developed and physiochemical properties were investigated. The water binding capacity had significantly the highest value of 28.4% in raw rice flour,
        4,000원
        194.
        2003.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyvinylpyrrolidone을 포함하는 폴리이미드 전구체의 열분해 공정을 통해 탄소분자체막을 제조하였으며 열분해성 고분자를 포함하는 전구체를 통해 제조된 막의 구조 및 기체 투과 특성에 대해 연구 하였다. 열분해성 고분자를 포함하는 전구체의 열적 특성을 조사한 결과 열적으로 안정한 폴리이미드의 경우 550℃에서 분해되는 것을 확인할 수 있었으며 열분해성 고분자의 경우 400℃에서 분해가 시작되는 것을 TCA를 통해 확인하였다 제조된 탄소분자체막의 기체 투과 특성을 조사한 결과 최종 열분해 온도가 증가됨에 따라 기체 투과도는 감소하였으며 열분해성 고분자를 포함한 전구체로부터 제조된 탄소분자체막의 경우 기체 투과가 향상됨을 알 수 있었다. 열분해성 고분자를 함유하는 전구체로부터 550℃에서 열분해를 통해 제조된 탄소분자체막의 경우 O2 투과도 808 Barrer [10-10cm3 (STP)cm/cm2scmHg]과 O2/N2선택도 7을 나타내었다.
        4,000원
        195.
        2002.10 구독 인증기관 무료, 개인회원 유료
        This paper presents an analysis for the variation of tool retraction length. Tool retraction, in zigzag pocket machining, is a non-productive operation in which the tool moves to any remaining regions for machining. Earlier, we developed an algorithm of generating tool retraction length in simple polygonal shapes. In the algorithm, we considered a reflex profile of cutting direction in a polygonal shape. Considering reflex profiles of cutting direction, the polygon is decomposed to subregions, triangles and quadrilaterals, which do not need any tool retraction. Consequently, we propose a new result that the shortest length of tool retraction presents a cutting direction parallel to concave edges. Examples are shown to verify the validity.
        4,000원
        197.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.
        198.
        2018.10 서비스 종료(열람 제한)
        Background : The human patch test is a method used to evaluate potential skin irritation after contact with a cosmetic materials. Pectin lyase-modified red ginseng extract (GS-E3D) is a newly developed ginsenoside Rd-enriched ginseng extract. This study was designed to investigate the skin safety of GS-E3D in human patch test. Methods and Results : Thirty two female volunteers were tested with GS-E3D. GS-E3D (20 ㎕) was applied to occlusive patch test devices and was then applied onto the back of subject with normal skin for 24 hours. Cutaneous irritation responses were evaluated and graded according to criterion of International Contact Dermatitis Research Group (ICDRG) at 30 min, 24 hours, and 48 hours after removing of GS-E3D patch. The average age of subjects was 47.3 ± 9.3 years. Skin reactivity calculated from irritation score in GS-E3D treated group was 0.51 and skin irritation score of no application group was 0, respectively. Skin irritancy was no response in both GS-E3D treated group and no application group. From above data, GS-E3D was identified as a non-irritant according to ICDRG guideline that skin irritation score of ‘0.00 - 0.75’ is a non-irritant. Conclusion : These results indicate that GS-E3D can be useful as a safe cometic ingredient.
        199.
        2018.10 서비스 종료(열람 제한)
        Background : Pectin lyase-modified red ginseng extract (GS-E3D) is a newly developed ginsenoside Rd-enriched ginseng extract. This study was designed to investigate the acute oral and dermal toxicity of GS-E3D in rat. Methods and Results : The acute oral toxic effects of GS-E3D in female SD rats were examined at dosages of 300 ㎎/㎏ and 2,000 ㎎/㎏. In acute dermal toxicity study, 500, 1,000 and 2,000 ㎎/㎏ of GS-E3D were applied onto the shaved skin of male and female SD rats. The weights of rats were recorded at 0, 1, 3, 7, and 14 days and clinical observation were checked once a day for a period of 14 days. All rats were scarified on 14th day and complete gross examination was conducted to detect any gross change of organs after necropsy. GS-E3D did not produce orally or dermally treatment-related clinical signs of toxicity or mortality in all rats during the 14-day observation period. The oral and dermal LD50 values of GS-E3D were over 2,000 ㎎/㎏ in rat. The oral and dermal administration of GS-E3D revealed no significant change in body weight and gross pathology examination compared to control group. Conclusion : These results indicate that GS-E3D can be used as a food and cosmetic materials without critically adverse effect.
        200.
        2018.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The characterization of detectors installed in space- and ground-based instruments is important to evaluate the system performance. We report the development of a detector performance test system for astronomical applications using the Andor iKon M CCD camera. The performance test system consists of a light source, monochromator, integrating sphere, and power meters. We adopted the Czerny–Tuner monochromator with three ruled gratings and one mirror, which covers a spectral range of 200–9,000 nm with a spectral resolution of ~1 nm in the visible region. Various detector characteristics, such as the quantum efficiency, sensitivity, and noise, can be measured in wide wavelength ranges from the visible to mid-infrared regions. We evaluated the Korea Astronomy and Space Science Institute (KASI) detector performance test system by using the performance verification of the Andor iKon-M CCD camera. The test procedure includes measurements of the conversion gain (2.86 e−/ADU), full well capacity (130 K e−), nonlinearity, and pixel defects. We also estimated the read noise, dark current, and quantum efficiency as a function of the temperature. The lowest measured read noise is 12 e−. The dark current at 223 K was determined to be 7 e−/s/pix and its doubling temperature is 5.3°C ± 0.2°C at an activation energy of 0.6 eV. The maximum quantum efficiency at 223 K was estimated to be 93 % ± 2 %. We proved that the quantum efficiency is sensitive to the operating temperature. It varies up to 5 % in the visible region, while the variation increases to 30 % in the near-infrared region. Based on the comparison of our results with the test report by the vendor, we conclude that our performance test results are consistent with those from the vendor considering the test environment. We also confirmed that the KASI detector performance test system is reliable and our measurement method and analysis are accurate.