• Title/Summary/Keyword: Bio-glass

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A 0.55" PDLC-LCoS Micro-display for Mobile Projectors

  • Do, Yun-Seon;Yang, Kee-Jeong;Sung, Shi-Joon;Kim, Jung-Ho;Lee, Gwang-Jun;Lee, Yong-Hwan;Chung, Hoon-Ju;Roh, Chang-Gu;Choi, Byeong-Dae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1527-1530
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    • 2009
  • A LCoS micro-display using polymer dispersed liquid crystals (PDLCs) for light switching layer was fabricated. The Si backplane of SVGA ($800{\times}600$) with a pixel size of $14{\times}14mm^2$ was prepared by a $0.35{\mu}m$ 18V CMOS process. PDLCs were filled in the gap between backplane and ITO glass by conventional vacuum filling method. The prepared panels were driven by a field sequential color (FSC) scheme at the frequency of 180Hz and were successful in modulating LED lights to show projection images. The preparation and performance of PDLC-LCoS are presented.

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Effect of Bioactive Glass Addition to the TTCP/DCPA Based Injectable Bone Substitute for Improved Biocompatibility

  • Sadiasa, Alexander;Sarkar, Swapan Kumar;Franco, Rose Ann;Yang, Hun-Mo;Lee, Byong-Taek
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.52.1-52.1
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    • 2011
  • In this work, the effect of the addition of bioactive glass in the biocompatibility and mechanical behavior of conventional TTCP/DCPA based bone cement were investigated. The cement was initially modified with chitosan and HPMC which cross-linked with citric acid to improved mechanical properties.The injectable bone substitutes were further modified by adding varying amounts of bioactive glass (0%, 10%, 20% and 30%) and its effects on the biocompatibility of the material were studied. Afterbio-glass powders were mixed with the optimized composition for HPMC and citric acid content,the IBS was incubated at $37^{\circ}C$ at different time intervals and showed progressive formation of HAp with increasing time. Mechanical properties like Vickers hardness and compressive strength were found to increase with the increasing amount of bioactive glass addition and that setting time was shortened. The fabricated IBS morphologies were further characterized using SEM. MTT assay was performed to check the cell cytotoxicity and cell proliferation for 1, 3 and 5 days. Cell morphology, adhesion and proliferation behavior of cell in the IBS by culturing MG-63 cells on the IBS for 20, 60 and 90 mins and 1, 3 and 5 days was also investigated. All the results showed increasing biocompatibility as the bioglass content increased. MTT results found the materials to be cytocompatible and SEM images showed that cells attached and proliferated successfully.

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바이오폴리올 함량에 따른 친환경 수분산 폴리우레탄의 합성 및 특성 (Synthesis and Properties of Eco-friendly Waterborne Polyurethane according to Bio-polyol Contents)

  • 장윤희;정부영;천정미;천제환;허필호
    • 접착 및 계면
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    • 제23권2호
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    • pp.33-38
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    • 2022
  • 본 연구에서는bio polyol 함량에 따라 bio polyol based 친환경 수분산 폴리우레탄을 합성하고 그 특성을 알아보고자 하였다. Polyester polyol(DT-1040)과 castor oil based polyol(COP)의 비율에 따른 bio polyol based 수분산 폴리우레탄을 성공적으로 합성한 것을 확인할 수 있었다. 합성된 bio polyol based 수분산 폴리우레탄의 Tg는 -70 ℃와 -30 ℃ 부근에서 나타났으며, COP의 함량이 증가할수록 유리전이온도 구간이 넓어지는 것을 확인할 수 있었다. 또한, COP의 함량이 증가할수록 인장강도는 감소하였고, 접착력은 DT-1040:COP=7:3일 때 최고값을 나타내었다.

The Preparation of Multi-walled CNT-PMMA Nanocomposite

  • Seo, D.W.;Yoon, W.J.;Park, S.J.;Jo, M.C.;Kim, J.S.
    • Carbon letters
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    • 제7권4호
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    • pp.266-270
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    • 2006
  • Multi-walled carbon nanotube-poly methyl methacrylate (MWNT/PMMA) nanocomposite has been prepared by in situ polymerization of MMA dispersed with MWNTs. The MWNTs were functionalized by nitric acid and sulfuric acid treatment, and this was confirmed by FTIR spectrometer. The solution mixture of MWNTs and MMA was partially polymerized at $80^{\circ}C$, followed by the addition of AIBN and polymerization at $50^{\circ}C$. The MWNT-PMMA composite was prepared by casting the pre-polymer on the glass plate, and the optical properties have been studied using UV-vis spectrometer. The acid treated MWNTs were well dispersed in MMA with fairly good dispersion stability, while flocculation and sedimentation was observed from raw MWNTs in MMA.

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유청으로부터 고정화 트립신을 이용한 기능성 펩타이드의 생산 (The Production of Functional Peptide from Whey Using Immobilized Trypsin)

  • 박윤주;윤여표;이형주;장해동
    • 한국식품과학회지
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    • 제28권1호
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    • pp.99-104
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    • 1996
  • 탄수화물을 갖고 있지 않은 caseinomacropeptide (CMP)를 감성유청분말로부터 12% TCA법에 의해 분리한 결과 100 g의 감성유청분말로 부터 2.7 g을 얻을 수 있었다. 분리된 CMP는 전기영동과 아미노산 조성을 분석한 결과 매우 순도가 높은 CMP로 나타나 12% TCA침전법은 감성유청분말로 부터 CMP를 분리하는 효과적인 방법임을 알 수 있었다. 트립신을 pore glass beads에 carbodiimide (EDC) 방법으로 amide결합에 의해 고정화시켰으며 고정화된 트립신의 양은 1 g glass beads당 20 mg이었다. 수용성 트립신에 의한 CMP 가수분해는 24시간이 지나면 거의 완료되었으며 고정화 트립신은 24시간이 지난 후에도 가수분해가 진행되고 있었다. 가수분해물을 Bio-Gel P4 column에 의해 분획한 후 혈소판 응집 저해작용을 측정한 결과 고정화 트립신에 의해 24시간 가수분해시킨 CMP 분해물이 가장 높은 혈소판 응집 억제능을 보였다.

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Viator vitreocola gen. et sp. nov. (Stylonematophyceae), a new red alga on drift glass debris in Oregon and Washington, USA

  • Hansen, Gayle I.;West, John A.;Yoon, Hwan Su;Goodman, Christopher D.;Goer, Susan Loiseaux-de;Zuccarello, Giuseppe C.
    • ALGAE
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    • 제34권2호
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    • pp.71-90
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    • 2019
  • A new encrusting red alga was found growing abundantly on glass debris items that drifted ashore along the coasts of Oregon and Washington. These included discarded fluorescent tubes, incandescent light bulbs, capped liquor bottles, and ball-shaped fishing-net floats. Field collections and unialgal cultures of the alga revealed that it consisted of two morphological phases: a young loosely aggregated turf and a mature consolidated mucilaginous crust. The turf phase consisted of a basal layer of globose cells that produced erect, rarely branched, uniseriate to multiseriate filaments up to $500{\mu}m$ long with closely spaced cells lacking pit-plugs. These filaments expanded in size from their bases to their tips and released single cells as spores. At maturity, a second phase of growth occurred that produced a consolidated crust, up to $370{\mu}m$ thick. It consisted of a basal layer of small, tightly appressed ellipsoidal-to-elongate cells that generated a mucilaginous perithallial matrix containing a second type of filament with irregularly spaced cells often undergoing binary division. At the matrix surface, the original filaments continued to grow and release spores but often also eroded. Individual cells, examined using confocal microscopy and SYBR Green staining, were found to contain a central nucleus, a single highly lobed peripheral chloroplast without a pyrenoid, and numerous chloroplast nucleoids. Morphological data from field and culture isolates and molecular data (rbcL, psbA, and SSU) show that this alga is a new genus and species which we name Viator vitreocola, "a traveller on glass."

마이크로 렌즈 어레이와 회절격자 레지스트 패턴을 이용한 유기광원(OLED)의 광 추출 효율 향상 (Outcoupling Enhancement of OLED using Microlens Array and Diffractive Grating)

  • 장지향;김경조;김진헌;오민철
    • 한국광학회지
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    • 제18권6호
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    • pp.441-446
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    • 2007
  • OLED 소자는 유리기판과 공기 층의 경계면에서 발생하는 전반사와 ITO-유기층으로 형성되는 광도파로를 따라 진행하는 도파모드 결합으로 인해 내부에서 생성된 빛의 80% 이상이 외부로 추출되지 못하게 된다. 본 연구에서는 마이크로 렌즈 어레이와 회절격자 레지스트 층을 이용하여 소자 내부에서 손실되는 빛을 외부로 추출시킴으로써 OLED의 발광효율을 향상시킨다. 마이크로 렌즈 어레이를 이용하여 유리기판-공기 전반사로 인해 내부에 갇히는 빛을 외부로 출력시키고, ITO 와 유기물 사이에 회절격자 레지스트 층을 삽입하여 ITO-유기층 광도파로에 갇힌 빛들을 수직방향으로 추출될 수 있도록 하였다. 제작된 OLED 소자에 전류밀도 $20mA/cm^2$를 인가한 경우, 마이크로 렌즈 어레이를 적용한 OLED에서 22%의 효율 개선을 얻었고, 회절격자 레지스트 층을 가지는 OLED 의 경우 41%의 효율개선을 얻을 수 있었다.

바이오 폴리올을 이용한 인공피혁 코팅용 폴리우레탄의 합성 및 특성 (Synthesis and Characterization of Polyurethane for Artificial Leather Using Bio Polyol)

  • 서석훈;최필준;고재왕;이재년
    • 한국염색가공학회지
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    • 제30권4호
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    • pp.321-328
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    • 2018
  • Wet polyurethane resin was synthesized by using polytrimethylene ether glycol prepared from 1,3-propanediol produced by fermentation from corn sugar as bio polyol and polyether-polyol(PTMG). Physical properties and cell characteristics by wet coagulation were investigated using the synthesized wet polyurethane resin. The tensile strength of wet polyurethane resin decreased with increasing content of bio polyol as copolymer polyol, but it tended to increase elongation at break and tear strength. As a result of thermal characteristic analysis, it was found that the glass transition temperature was slightly increased as the content of bio polyol increased. As a result of comparing the cell characteristics by the wet coagulation method, it was found that the shape of the cell was good when the ether polyol and the bio polyol were used alone.

Influence of specimen height on the shear behavior of glass beads in the direct shear test

  • Young-Ho Hong;Yong-Hoon Byun;Jong-Sub Lee
    • Geomechanics and Engineering
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    • 제34권4호
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    • pp.461-472
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    • 2023
  • A box scale affects the shear behavior of soils in the direct shear test. The purpose of this study is to investigate the scale effect on the shear behavior of dilative granular materials by testing specimens of different heights placed in a type C shear box. Experimental tests were performed on specimens composed of glass beads with different heights and equal initial void ratios. Results showed that the peak friction and dilation angles linearly increased with the specimen height; however, the residual friction angle remained relatively constant. Similarly, the shear stiffness increased with the specimen height, rapidly reaching its peak state. Height does not have a significant effect on the total volume changes; nevertheless, a high aspect ratio can be assumed to result in global and homogeneous failure. The results and interpretations may be used as reference for recommending shear box scale in direct shear tests.