• Korea-Australia Rheology Journal
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• 제14권3호
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• pp.121-128
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• 2002

A series of thermoplastic polymers and their blends were melt-processed with high intensity ultrasonic wave in an intensive mixer. For the effective transfer of ultrasonic energy, an experimental apparatus was specially designed so that polymer melt can directly contact with ultrasonic horn. It was observed that significant variations in the rheological properties of polymers occur due to the unique action of ultrasonic wave without any aid of chemical additives. It was also found that the direct sonication on immiscible polymer blends in melt state reduces the domain sizes considerably and stabilizes the phase morphology of the blends. The degree of compatibilization was strongly affected by viscosity ratio of the components and the morphology was stable after annealing in properly compatibilized blends. It is suggested that ultrasound assisted melt mixing can lead to in-situ copolymer formation between the components and consequently provide an effective route to compatibilize immiscible polymer blends.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.180-181
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• 2019

In this study, in order to find new uses for CBS dust, the chemical components of CBS dust were analyzed and effectively proposed a method. Chemical analysis shows that CBS dust contains a large amount of alkali in addition to chloride therefore, if CBS dust is used for secondary concrete products that use high amounts of mixed materials without rebars, it will be found that it can be used effectively for enhancing strength by active alkali.

• Macromolecular Research
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• 제11권5호
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• pp.303-310
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• 2003

The phase behavior of binary blends of dimethylpolycarbonate-tetramethyl polycarbonate (DMPCTMPC) copolycarbonates and styrene-acrylonitrile (SAN) copolymers has been examined and then compared with that of DMPC/TMPC/SAN ternary blends having the same chemical components and compositions except that the DMPC and TMPC were present in the form of homopolymers. Both binary and ternary blends were miscible at certain blends compositions, and the miscible blends showed the LCST-type phase behavior or did not phase separated until thermal degradation temperature. The miscible region of binary blends is wider than that of the corresponding ternary blends. Furthermore, the phase-separation temperatures of miscible binary blends are higher than those of miscible ternary blends at the same chemical compositions. To explain the destabilization of polymer mixture with the increase of the number of component, interaction energies of binary pairs involved in these blends were calculated from the phase separation temperatures using lattice-fluid theory and then the phase stability conditions for the polymer mixture was analyzed with volume fluctuation thermodynamics.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3120-3122
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• 2011

• 대한화학회지
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• 제25권5호
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• pp.334-338
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• 1981

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2003년도 추계정기총회 및 국제심포지엄
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• pp.61-65
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• 2003

• 한국연초학회지
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• 제22권2호
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• pp.170-175
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• 2000

This study was carried out to compare the quality of licorices from various cultivating areas. licorice samples used in this study were collected from North-east and Sinkiang area in China, Mongolia, Uzvekistan and Kazahstan. The chemical components of licorice samples were analyzed and the signal patterns of the electracts were detected by the electronic nose. Contents of glycyrrhizin and glicyrrhizic acid, the key components of licorice were distributed in the region of 16.7～25.2% and 5.8～10.2%, respectively and were various according to the samples of the collected areas. In glycyrrhizin contents, root of Sinkiang showed the lowest value of 16.7%, and that of North-east the highest of 25.2%. In glycyrrhizic acid contents, root of Sinkiang showed the lowest of 5.8 %, and Kazahstan showed the highest of 10.2 %. Composition ratio of glycyrrhizin to glycyrrhizic acid was not always limear. As other components is other components affecting quality, contents of ash, starch and gums were 2.4～3.7%, 0.2～3.9%, respectively. When the headspace volatiles of licorices were analyzed using Electronic Nose System and the obtained data were interpreted using statistical method of MANOVA, characteristic patterns of licorices were different from each other according to collected area and its p value showed 0.0001. These results suggest that licorices may be discriminated from the collected areas by using Electronic Nose System.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2002년도 춘계학술발표회 논문집
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• pp.46-49
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• 2002

• 한국작물학회지
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• 제41권3호
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• pp.354-361
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• 1996

신속하고 정확한 근적외선 분광분석법으로 품질분석의 효율성을 증대하기 위하여 화학성분의 변이분포가 검량식 작성과정에 미치는 영향과 측정 정확성에 미치는 관계를 구명하여, 근적외선 분광광도계의 이용 효율성 제고를 위한 기초자료를 얻고자 실시한 실험의 결과는 다음과 같다. 1. 보리 전분에 대한추정치 표준오차는 변이폭이 증대될수록 증가하는 경향을 보였으며, 상관계수도 변이폭이 증대될수록 0.872에서 0.883으로 다소 높아지는 경향을 나타내었다. 2. $eta$-glucan과 단백질은 변이폭이 증대될수록 추정치 표준오차는 낮아지고 상관계수는 높아지는 결과를 보여, 근적외선 분광분석법의 이용성 향상을 위하여서는 이들 성분의 함량변이 확대가 필요할 것으로 생각되었다. 3. 회분은 첫번째와 두번째 group에서는 유의성이 인정되지 않았으나, 세번째 group에서는 상관계수가 0.743으로 유의성이 인정되어 회분함량의 경우에는 어느 정도의 변이폭이 있어야만 근적외선 분광분석법이 가능할 것으로 생각되었다. 4. 겉보리 성분 중 전분과 회분은 재검토가 이루어져야 할 것으로 생각되었으며, $\beta$-glucan과 단백질은 근적외선 분광분석법의 적용이 가능하여 분석의 효율성이 증대될 것으로 생각되었다.

• 한국융합학회논문지
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• 제12권2호
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• pp.193-200
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• 2021

화석 연료 사용으로 인한 각종 환경오염의 정도가 심화됨에 따라 많은 국가에서 대체 에너지 개발을 위한 투자를 계속해서 진행하고 있다. 대체 에너지 중 하나인 PEMFC는 양극판, 전해질, 가스 확산 층, 전극 네 가지의 주요 구성요소로 이루어져 있다. 이 중 양극판, 가스 확산 층, 전극은 보편적으로 카본 블랙, 탄소 섬유 등의 탄소 재료를 사용하여 제조한다. 탄소 재료들은 공정비용이 비싸거나 부식 등의 단점이 존재하는데 이를 개선하기 위해 많은 분야에서 연구가 진행되고 있다. 본 논문은 이 세 가지 구성요소들의 단점을 개선하기 위하여 시행된 여러 연구결과들을 취합하여 과거부터 현재까지의 PEMFC에 어떤 문제점이 있었고 어떻게 개선되어 왔는지를 파악하여 PEMFC 연구 흐름을 파악한다.