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Polymerization of Hydrogel Contact Lens with High Oxygen Transmissibility (산소투과성이 뛰어난 Hydrogel 콘택트렌즈 합성)

  • Sung, A-Young;Kim, Tae-Hun;Kong, Jung-Il
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.1
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    • pp.49-53
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    • 2006
  • Acrylate -PDMS(Polydimethylsiloxane)-Urethane Prepolymer is synthesized through treating diisocynate, HEMA(2-hydroxyethylmethacrylate) and bis(hydroxyalkyl)terminated Poly(dimethylsiloxane) having high oxygen permeability under the DBTDL(Dibutylitin dilaurate) catalyst. Modification of HEMA on bis(hydroxyalkyl)terminated Poly(dimethylsiloxane) is to be able to polymerize with other contact lens materials. And modification of urethane on bis(hydroxyalkyl)terminated Poly(dimethylsiloxane) is to increase elastic property and oxygen transmissibility. This material is analyzed by FT-IR and also will be used to make hydrogel contact lens.

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Ion Gel Gate Dielectrics for Polymer Non-volatile Transistor Memories (이온젤 전해질 절연체 기반 고분자 비휘발성 메모리 트랜지스터)

  • Cho, Boeun;Kang, Moon Sung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.12
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    • pp.759-763
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    • 2016
  • We demonstrate the utilization of ion gel gate dielectrics for operating non-volatile transistor memory devices based on polymer semiconductor thin films. The gating process in typical electrolyte-gated polymer transistors occurs upon the penetration and escape of ionic components into the active channel layer, which dopes and dedopes the polymer film, respectively. Therefore, by controlling doping and dedoping processes, electrical current signals through the polymer film can be memorized and erased over a period of time, which constitutes the transistor-type memory devices. It was found that increasing the thickness of polymer films can enhance the memory performance of device including (i) the current signal ratio between its memorized state and erased state and (ii) the retention time of the signal.

Rennet-induced gels and their mechanical properties (우유의 렌넷 젤에 대한 기계적 특성)

  • Choi, Jong-Woo
    • Korean Journal of Agricultural Science
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    • v.38 no.4
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    • pp.711-716
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    • 2011
  • Casein micelles are the basic building block of rennet-induced gels. The stiffness of these gels is increased with reaction time. This is probably due to the continuous participation of activated casein micelles into growing network. Dual binding model of casein micelles, which explains assembly of casein and colloidal calcium phosphate, can provides fairly reasonable explanation for the changes in mechanical properties of rennet-induced gels made from different milk pHs and varying colloidal calcium phosphates. The changes in stiffness of these gels would be used for controlling textural properties of cheeses.

Sol-gel Spin-coating of ZnO Co-doped with (F, Ga) as A Transparent Conducting Thin Film ((F, Ga) 코도핑된 ZnO 투명 전도 박막의 솔-젤 제조와 특성)

  • Nam, Gil Mo;Kwon, Myoung Seok
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.1
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    • pp.91-95
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    • 2014
  • (F,Ga) co-doped ZnO thin film on glass substrate was fabricated via a simple non-alkoxide sol-gel spin-coating. Contrary to the F single doped ZnO thin film, the (F,Ga) co-doped thin film showed a significant reduce in electrical resistivity after a second post-heat-treatment in reducing environment. The resulting decrease in electrical resistivity with Ga co-doping is considered to be resulted from the increases both carrier density and mobility. The optical transmittance of the (F,Ga) co-doped thin film in the visible range showed higher transmittance with Ga co-doping compared with F single doped ZnO thin film.

Structure and Textural Property of Mook (묵의 구조와 텍스쳐)

  • Bae, Kwang-Soon;Sohn, Kyung-Hee;Moon, Soo-Jae
    • Korean Journal of Food Science and Technology
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    • v.16 no.2
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    • pp.185-191
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    • 1984
  • The structure and textural properties of the traditional starch gel-form food Mook were investigated with the use of the Scanning Electron Microscope and Instron universal testing machine. Sensory evaluation was undertaken to evaluate the relationship between structure and textural properties of starch gel. When pure mungbean, potato, and sweet potato starches as well as 30% mungbean starches added to potato and to sweet potato starches were evaluated, it was found that mungbean starch gel had homogeneous and porous structure and showed the highest acceptability.

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구조 세라믹스의 분말 성형 공정

  • Lee, Hae-Won;Song, Hyu-Seop;Kim, Ju-Seon;Sin, Hyeon-Ik;Im, Geon-Ja;Choe, In-Muk;Mun, Hwan;Yun, Bok-Gyu;Jeon, Hyeong-U
    • Ceramist
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    • v.4 no.3
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    • pp.18-28
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    • 2001
  • 세라믹스 부품의 실형상 제조기술은 실형상 성형기술과 더불어 반응소결기술의 발달에 의하여 거의 수축율이 제로인 기술로 발달하고 있다. 분말사출성형으로 대표되던 실형상 성형기술도 젤 캐스팅과 열경화 몰딩과 같은 화학적 성형기술의 도입에 따라 플라스틱과 같이 쉽게 부품을 성형할 수 있는 상태에 도달하고 있다. 특히, 나노분말의 실형상 성형은 화학적 방법에 의해서만 가능할 것으로 예상된다.

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Electrochemical Characteristics of Aqueous Polymeric Gel Electrolyte for Supercapacitor (수퍼커패시터용 수용성 고분자 젤 전해질의 전기화학적 특성)

  • ;Masashi ISHIKAWA;Masayuki MORITA
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.93-96
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    • 2001
  • We have reported to make nanostructured cobalt oxide electrode that have large capacitance over than 400F/g (specific capacitance) and good cycleability. But, It had serious demerits of low voltage range under 0.5V and low power density. Therefore, we need to increase voltage range of cobalt oxide electrode. we report here on the electrochemical properties of sol-gel-derived nanoparticulate cobalt xerogel in 1M KOH solution and aqueous polymeric gel electrolyte. In solution electrolyte, cobalt oxide electrode had over than 250F/g capacitance consisted of EDLC and pseudocapacitance. In gel electrolyte, cobalt oxide electrode had around 100F/g capacitance. This capacitance was only surface EDLC. In solution electrolyte, potassium ion as working ion reacted with both of layers easily. However, In gel electrolyte, reacted with only surface-active layer. Its very hard to reach resistive layer. So, e have studied on pretretmetn of electrode to contain working ions easily. We'll report more details.

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Automated System on Extracting Digital Pattern for TDGS Image Analysis (TDGS 영상 분석을 통한 자동적 디지털 패턴의 추출)

  • Chang, Hwan;Park, You-Na;Lee, Bog-Ju
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.05a
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    • pp.707-710
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    • 2003
  • 본 논문은 2차원 전기영동에 의해 나타나는 TOGS 영상을 분석하기 위한 시스템으로 실험적인 특성상 젤 위에 나타나는 반점들의 불규칙한 요소들이 많고 영상의 상태가 좋지 않은 경우 명암도가 떨어지는 반점들의 구분이 힘들게 된다. 기존의 전문가의 육안에 의한 TDGS 영상 분석은 그러한 불안적 요소들에 대해 유연하게 대처할 수 있는 능력이 있었다. 하지만, 그러한 예외적인 경우를 컴퓨터가 처리하기 위해서는 영상의 지역적 상태에 맞는 융통성 있는 영상처리 과정이 필요하고, 실제 분석에 사용되지 않는 반정들을 제외한 유효한 디지털 패턴의 판별이 요구된다. 이에 본 논문에서는 영상의 지역적 특성을 효과적으로 반영한 동적 이진화 방법을 통해 후보 패턴들을 추출하고, 모든 샘플들의 기준이 되는 Reference 패턴과 후보 패턴의 point matching 과정을 통해 디지털 패턴을 추출한다.

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Characterization of Vitamins in Yeast Extract using Gel Filtration, Ion Exchange Chromatography and HPLC (젤 여과, 이온 크로마토그래피와 HPLC에 의한 효모 엑기스내의 비타민의 분석연구)

  • 최인호;홍억기;강환구;김인호
    • KSBB Journal
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    • v.15 no.1
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    • pp.76-79
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    • 2000
  • Complex, ill-defined mixtures of natural origin are often used as nutrients in the production of biological products through microbial fermentation. Product yields are affected by variation in these natural products. Yeast extract is a typical example of these natural products. Since it is a mixture of amino acids, peptides and nucleic acids, its composition is not well characterized. In this study, we investigated the properties of thiamine hydrochloride, riboflavin and pyridoxine hydrochlride in yeast extract by using a gel filtration chromatography, ion exchange chromatography and high performance liquid chromatography. Yeast extract solution was fractionated by gel filtration chromatography and ion exchange chromatography, and then, each fraction was analyzed by using a high performance liquid chromatography.

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Detection of Cucumber Mosaic Virus by RT-PCR Using a Simple and Rapid Crude Sap Extraction Method (간이 조즙액 추출법을 이용한 RT-PCR 방법에 의한 오이 모자이크 바이러스의 검정)

  • 이상용;홍진성;이진상;최장경
    • Korean Journal Plant Pathology
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    • v.12 no.4
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    • pp.432-436
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    • 1996
  • 역전사 중합효소 연쇄반응(RT-PCR)을 이용하여 담배(Nicotiana glutinosa)에 증식시킨 7종의 오이 모자이크 바이러스(CMV)를 검정하였다. RT-PCR을 위한 간단하고 신속한 바이러스 핵산의 조즙액 추출법이 개발되었으며, CMV 외피단백질 유전자 부위를 기초로 하여 제작한 20개의 염기로 구성된 primer를 사용하여 RT-PCR을 실시한 결과, 약 490 염기쌍의 DNA 단편들이 이병식물의 조즙액으로부터 증폭되었다. EcoRI 및 MspI을 이용한 RT-PCR 산물의 분석에 의하여, 공시한 7종의 바이러스는 모두 CMV subgroup I으로 동정되었다. Ouchterlony 한천젤 이중 확산법을 이용한 항혈청 검정에서도 7종의 바이러스 모두 CMV-Y의 항혈청과 단일의 침강선을 형성하였다.

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