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        검색결과 64

        21.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzes the chemical composition of green tea, white tea, yellow tea, oolong tea and black tea with respect to extraction temperature and time. The optimum extraction conditions for these teas were determined by assessing the chemical composition of tea brewed at different temperature (50, 60, 70, 80℃) and extraction times (1, 3, 5, 10 minute). Catechins contents were the largest at 5 minutes and generally declined by 10 minutes. Green tea catechins contents were highest when brewed at 70℃ and besides other teas a change of the trend variation at 70 and 80℃. These temperatures did not extract theaflavins in green tea. Extract temperature and time did not significantly affect theaflavins content of white tea, yellow tea, and oolong tea. Black tea, however, was noticeably dependent on extract conditions, which were most effective at 70℃, brewed for 5 minutes. Caffeine content of green tea, yellow tea, and oolong tea was highest at 5 minutes, but temperature did not appear to affect the content. White tea and black tea caffeine content was highest when brewed at 70℃ for 5 minutes. Theobromine content of green tea, yellow tea, oolong tea, and black tea did not show major differences between the study times or temperature, though the content in white tea increased with higher temperatures when brewed for 5 minutes. The extraction of phenolic compounds increased until 5 minutes, and showed not further increase at 10 minutes. Antioxidant capacity of green tea, white tea, and yellow tea were maximized at 70℃ for 5 minutes or 80℃ for 3 minutes, while oolong and black tea were reached maximum antioxidants at 70℃ for 5 minutes. In general, to optimize the beneficial chemical content of brewed tea, a water temperature of 70℃ for 5 minutes is recommended.
        4,000원
        22.
        2015.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        CMP(Chemical Mechanical Polishing) Processes have been used to improve the planarization of the wafers in the semiconductor manufacturing industry. Polishing performance of CMP Process is determined by the chemical reaction of the liquid sol containing abrasive, pressure of the head portion and rotational speed of the polishing pad. However, frictional heat generated during the CMP process causes agglomeration of the particles and the liquidity degradation, resulting in a non-uniform of surface roughness and surface scratch. To overcome this chronic problem, herein, we introduced NaCl salt as an additive into silica sol for elimination the generation of frictional heat. The added NaCl reduced the zata potential of silica sol and increased the contact surface of silica particles onto the sapphire wafer, resulting in increase of the removal rate up to 17 %. Additionally, it seems that the silica particles adsorbed on the polishing pad decreased the contact area between the sapphire water and polishing pad, which suppressed the generation of frictional heat.
        4,000원
        23.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Landfills are nettlesome sources of malodorous gases as well as methane that has the second largest radiative forcing of long residence-greenhouse gases, followed carbon dioxide. Because methane and malodorous gases are simultaneously emitted in landfills, investigation of whether or not methane and malodorous gases affect each other’s degradation is important. Amines such as monomethylamine(MMA), dimethylamine(DMA) and trimethylamine(TMA) are representative malodorous gases from landfills. In this study, the effect of amines on the bio-oxidation of methane was evaluated using a methane-oxidizing consortium where the dominant bacteria were Methylocystis spp. Amines inhibited the methane oxidation by the consortium, and the inhibition effect increased in the order of TMA > DMA > MMA. Methane oxidation rates in the consortium decreased with increasing amine/methane ratio(mol/mol). These results can be used to design and optimize the biological processes for simultaneous removal of methane and malodorous gases.
        4,000원
        24.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rhizosphere and non-rhizosphere soils were sampled from landfill area, riparian wetland, and rice paddy. The consortia were obtained by methane enrichment culture using the soils. The effects of ammonia on methane oxidation in the consortia were evaluated. Compared with methane oxidation rates without ammonia, the rates with ammonia of 1mg-N/bottle were similar or slightly lower. However, their methane oxidation rates were significantly reduced with 2~4mg-N ammonia/bottles. The effect of ammonia on the methanotrophic abundance was estimated by using a quantitative real-time PCR method targeting particulate methane monooxygenase gene. Ammonia didn’t negatively influence on the methanotrophic abundance although it inhibited the methane oxidation activity by methanotrophs.
        4,000원
        25.
        2009.07 구독 인증기관 무료, 개인회원 유료
        6,100원
        26.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pyridine could be successfully removed in the polyurethane(PU) biofilter inoculated with activated sludge treating industrial wastewater. The elimination capacity for pyridine in the PU biofilter was approximately 27 g m⁻³ h⁻¹ at the tested loading range, The pH value of drainage was increased due to the accumulation of ammonia which was one of the metabolites of pyridine, Four pyridine-degrading bacteria were isolated from the PU biofilter, and they were closely related with Rhodococcus pyridinivorans(98~99% similarity). The specific growth rate of the isolate in the medium supplemented with pyridine as a sole carbon and energy source were ranged from 0.038 h⁻¹ to 0.051 h⁻¹.
        4,000원
        28.
        2005.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        29.
        2005.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        3,000원
        32.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근까지 제품디자인에 있어서의 조형요소의 심미성에 관한 연구가 많이 진행되어 왔다. 그러나 기존의 연구는 "심미성 요인이 무엇인가\ulcorner"에 초점을 맞추어 왔을 뿐 각각의 심미적 요소들이 사용자의 심미적 반응에 어떻게 영향을 미치는지에 대해서는 그다지 연구된 바가 없다. 따라서 본 연구는 제품디자인에서 심미성 요소를 내용미와 형태미로 나누어 서로의 상관관계를 파악하고 사용자의 심미적 반응에 어떠한 영향을 미치는지를 알아보는 연구이다. 더욱이 연구의 초점이 내용미 중 전형성을, 형태미 중 균형을 중심으로 서로의 심미적 반응의 영향정도와 관여수준과 국가와 같은 조절변수에 의해 심미적 반응이 어떻게 달라지는지를 검증하고자 하기 위한 연구이다. 본 연구를 통하여 실제로 디자인 현장이나 기업에서 디자인에 있어서 심미적 영향요소를 적용하는 데에 대한 의미 있는 시사점을 제공해주고 디자인의 심미성에 대한 이론적인 체계를 만들어가는 것에 기여하리라 본다. 기여하리라 본다.
        4,200원
        33.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        34.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        36.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        더욱이 경쟁이 치열한 시장 환경 속에서 소비자의 선호요인 중 심미성이 중요하게 부각되는 현실에서 소비자의 라이프스타일의 변화와 그에 따른 소비자의 의식변화를 통해 소비자의 상품구매 기준 역시 변화를 가져왔다. 이렇게 변화하는 소비자의 욕구를 만족시키기 위해서는 디자인 기술과 방법 또한 그에 따른 변화가 필요하다. 따라서 본 연구는 범주화 이론(Categorization theory)을 통한 전형성과 동시에 중요하게 인지되는 심미성의 개념적 구조를 파악하고, 심미적 영향 요소 중 한글서체와 관련성이 있다고 여겨지는 율동(rhythm)을 선정하여 이를 이미지 형태조작에 활용함으로써 다양한 형태발상을 유도한 새로운 디자인 프로세스를 구축함으로서 디자이너의 아이디어 발상의 한계성을 극복하고 소비자가 선호할 수 있는 디자인을 창출하여 디자인의 성공 확률을 높이고자 한다.
        4,500원
        37.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,200원
        38.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        39.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
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