• Title/Summary/Keyword: Bio-glass

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Enhanced thermomechanical properties of poly(ethylene oxide) and functionalized bacterial cellulose nanowhiskers composite nanofibers

  • Yun, Ok-Ja
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.376-376
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    • 2016
  • Poly(ethylene oxide) (PEO)/functionalized bacterial cellulose nanowhiskers (f-BCNW) (0.1 wt%) composite nanofibers were fabricated by electrospinning process and the thermomechanical properties were significantly enhanced more than the PEO and PEO/bacterial cellulose nanowhiskers (BCNW) (0.1 wt%) composite nanofibers. The functionalization of BCNW (f-BCNW) was performed by microwave plasma treatment for effects of nitrogen functionalization of chemically-driven BCNW. The N-containing functional groups of f-BCNW enhanced chemical bonding between the hydroxyl groups of the polymer chains in the PEO matrix and diameter size of PEO/f-BCNW (0.1 wt%) composite nanofibers were decreased more than PEO and PEO/BCNW (0.1 wt%) composite nanofibers on the same concentration. The strong interfacial interactions between the f-BCNW nanofillers and polymer matrix were improved the thermomechanical properties such as crystallization temperature, weight loss and glass transition temperature (Tg) compared to PEO and PEO/BCNW composites nanofibers. The results demonstrated that N2 plasma treatment of BCNW is very useful in improving thermal stability for bio-applications.

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Infrared Scanning Near-Field Optical Microscopy (IR-SNOM) Below the Diffraction Limit

  • Sanghera, J.S.;Aggarwal, I.D.;Cricenti, A.;Generossi, R.;Luce, M.;Perfetti, P.;Margoritondo, G.;Tolk, N.;Piston, D.
    • Ceramist
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    • v.10 no.3
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    • pp.55-66
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    • 2007
  • Infrared Scanning Near-field Optical Microscopy (IR-SNOM) is an extremely powerful analytical instrument since it combines IR spectroscopy's high chemical specificity with SNOM's high spatial resolution. In order to do this in the infrared, specialty chalcogenide glass fibers were fabricated and their ends tapered to generate SNOM probes. The fiber tips were installed in a modified near field microscope and both inorganic and biological samples illuminated with the tunable output from a free-electron laser located at Vanderbilt University. Both topographical and IR spectral images were simultaneously recorded with a resolution of ${\sim}50\;nm$ and ${\sim}100\;nm$, respectively. Unique spectroscopic features were identified in all samples, with spectral images exhibiting resolutions of up to ${\lambda}/60$, or at least 30 times better than the diffraction limited lens-based microscopes. We believe that IR-SNOM can provide a very powerful insight into some of the most important bio-medical research topics.

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Evolutionary Neural Networks based on DNA coding and L-system (DNA Coding 및 L-system에 기반한 진화신경회로망)

  • 이기열;전호병;이동욱;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.107-110
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    • 2000
  • In this paper, we propose a method of constructing neural networks using bio-inspired emergent and evolutionary concepts. This method is algorithm that is based on the characteristics of the biological DNA and growth of plants. Here is, we propose a constructing method to make a DNA coding method for production rule of L-system. L-system is based on so-called the parallel rewriting mechanism. The DNA coding method has no limitation in expressing the production rule of L-system. Evolutionary algorithms motivated by Darwinian natural selection are population based searching methods and the high performance of which is highly dependent on the representation of solution space. In order to verify the effectiveness of our scheme, we apply it to one step ahead prediction of Mackey-Glass time series.

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DNA Coding Method for Time Series Prediction (시계열 예측을 위한 DNA 코딩 방법)

  • 이기열;선상준;이동욱;심귀보
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.280-280
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    • 2000
  • In this paper, we propose a method of constructing equation using bio-inspired emergent and evolutionary concepts. This method is algorithm that is based on the characteristics of the biological DNA and growth of plants. Here is. we propose a constructing method to make a DNA coding method for production rule of L-system. L-system is based on so-called the parallel rewriting mechanism. The DNA coding method has no limitation in expressing the production rule of L-system. Evolutionary algorithms motivated by Darwinian natural selection are population based searching methods and the high performance of which is highly dependent on the representation of solution space. In order to verify the effectiveness of our scheme, we apply it to one step ahead prediction of Mackey-Glass time series.

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Evolutionary Neural Network based on DNA Coding Method for Time Series Prediction (시계열 예측을 위한 DNA코딩 기반의 신경망 진화)

  • 이기열;이동욱;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.05a
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    • pp.224-227
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    • 2000
  • In this Paper, we prepose a method of constructing neural networks using bio-inspired emergent and evolutionary concepts. This method is algorithm that is based on the characteristics of the biological DNA and growth of plants. Here is, we propose a constructing method to make a DNA coding method for production rule of L-system. L-system is based on so-called the parallel rewriting mechanism. The DNA coding method has no limitation in expressing the production rule of L-system. Evolutionary algorithms motivated by Darwinian natural selection are population based searching methods and the high performance of which is highly dependent on the representation of solution space. In order to verify the effectiveness of our scheme, we apply it to one step ahead prediction of Mackey-Glass time series, Sun spot data and KOSPI data.

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Fabrication of 2-D Microwell Arrays for Micro ELISA System (초소형 면역 분석기용 이차원적 배열형 마이크로 우물 제작)

  • Lee, Kook-Nyung;Ahn, Si-Hong;Park, Jae-Hyung;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2556-2558
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    • 1998
  • 2-D microwell arrays for micro ELISA (Enzyme-Linked Immuno Solvent Assay) system were fabricated using micromachining technology. The materials for the bottom plate, top plate and sidewall of the microwell were used a #7740 glass, gold and silicon respectively considering bio-compatibility and easy fabrication. Cylindrical or groove shape microwells, which have about $100{\mu}m$ depth and $50{\sim}500{\mu}m$ diameter or width, were arrayed. The fabricated microwell array can be applied to the essential part of a biochip when surface modification is made to immobilize cells or biomolecules on the microwell bottom.

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Reinforcement of Porous Mullite Ceramics Using Ultra Fine Mullite Precursor Powders

  • Cho, Yong-Ick;Hisao Suzuki;Hidehiro Kamiya
    • The Korean Journal of Ceramics
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    • v.5 no.2
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    • pp.137-141
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    • 1999
  • To increase the strength of high-purity porous mullite ceramics, ultra fine mullite precursor powders of about 10nm in diameter were deposited at point of contact between primary coarse mullite particles of about 60$\mu\textrm{m}$. The deposited and hetero coagulated structures of ultra fine mullite precursor powders were controlled by pH. The optimum pH condition to form a uniform deposition of mullite powders between coarse mullite particles was in the range from 7 to 8. Deposition of the ultra fine powders did not form at pH < 7 and pH > 10 irregular deposition was observed from pH 8 to 9.

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Property Comparison of Bio-Polyurethane and Petroleum based Polyurethane (바이오 폴리우레탄과 석유기반 폴리우레탄의 물성 비교)

  • Lee, Dam Hee;Lee, Kwan Hee;Cho, Ur Ryong
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.2
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    • pp.47-52
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    • 2018
  • The three polyols, poly(trimethylene ether) glycol 2000, poly(tetramethylene ether) glycol 2000 and poly (tetramethylene ether) glycol 1000 were reacted with 4,4-diphenylmethane diisocyanate to get polyurethanes. The synthesized three polyurethanes were measured by FT-IR, NMR for investigating chemical structures. Through two spectroscophical methods, It is found that urethane group exists in the three polymers. From the evaluation of hardness, glass transition temperature, tensile strength, and water resistance, the results showed increasing order of Poly(tetramethylene ether) glycol 1000 > Poly(trimethylene ether) glycol 2000 > Poly(tetramethylene ether) glycol 2000 with the content of hard segment in polyurethane.

Determination of carvedilol in human plasma by high-performance liquid chromatography

  • Lee, Jung-Ae;Lee, Ye-Rie;Kim, Ho-Hyun;Lee, Hee-Joo;Lee, Kyung-Ryul
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.220.1-220.1
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    • 2003
  • A sensitive and selective liquid chromatographic method for the determination of carvedilol in human plasma was developed and validated. Analytes were separated on a XTerra C18 column with acetonitrile-methanol-30 mM KH$_2$PO$_4$ (pH 2.5) (20 : 20 : 60, v/v/v), as mobile phase. One mL plasma were pipetted into glass tubes and spiked with 0.05 mL of internal standard solution. After adding 7 mL of diethyl ether, the plasma sample was then shacked for 15 min. A centrifuged upper layer was back-extracted with 150 uL of 0.05 M sulfuric acid. (omitted)

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Effect of nanosilica and TEOS in hydrophilic coating solution on the surface characteristics of solar cell glass panel (나노실리카와 TEOS가 함유된 친수성 코팅액의 태양광 유리팬널에 미치는 표면 특성 연구)

  • Lee, Soo;Kim, Seung Hye;Hwang, Heon
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.1
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    • pp.152-162
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    • 2017
  • A hydrophilic coating solution was prepared by adding a silane coupling agent and a nano-inorganic oxide in aqueous surfactant solution to increase the efficiency of photovoltaic power generation due to the introduction of antifogging and antifouling properties on the glass surface of the solar cell module. Addition of $Ludox^{(R)}$, a nano-inorganic oxide, to 1% hydrophilic coating solution showed improved hydrophilicity and excellent antifogging effect regardless of $Ludox^{(R)}$ concentration. However, the antifouling effect on the glass surface was showed only when Ludox was added more than 10%. In the case of addition of 0.7% of hydrolyzed TEOS at pH 4, the antifogging effect was maintained as a result of the steam test as well as the antifouling effect even after the coated glass surface was rubbed 100 times with a wet Kimwipe. In addition, from the surface roughness ($R_q$) calculated using AFM data, the higher surface roughness with irregular surface shape was obtained with the higher concentration of TEOS. The addition of 0.7% of TEOS showed relatively high surface roughness and well organized surface condition which can help to improve transmittance of light. In conclusion, $Ludox^{(R)}$ is not required only for the antifogging property. However, at least 10% of Ludox should be added to show antifouling effect and 0.7% of TEOS should be added for good durability.