• 제목/요약/키워드: gels

검색결과 729건 처리시간 0.023초

Laccase Induced Maize Bran Arabinoxylan Gels: Structural and Rheological Properties

  • Berlanga-Reyes, Claudia M.;Carvajal-Millan, Elizabeth;Juvera, Graciela Caire;Rascon-Chu, Agustin;Marquez-Escalante, Jorge A.;Martinez-Lopez, Ana Luisa
    • Food Science and Biotechnology
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    • 제18권4호
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    • pp.1027-1029
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    • 2009
  • The aim of this research was to study the structural and rheological properties of gels formed by ferulated maize bran arabinoxylans (MBAX) at different concentrations. MBAX was cross-linked by a laccase leading to the formation of dimers and trimers of ferulic acid (di-FA, tri-FA) as covalent cross-link. An increase in MBAX gels elasticity (from 11 to 20 Pa) as well as lower mesh size (from 80 to 48 nm) were obtained by augmenting the MBAX concentration from 2.5 to 3.5%(w/v), respectively, but no increase in di-FA and tri-FA content was obtained (0.03 and 0.014 ${\mu}$g/mg MBAX, respectively).

수화겔의 상전이에 관한 연구: (I)폴리(N-이소프로필아크릴아미드)겔의 부피상전이 (A study on phase transition of Hydrogel: (I)Volume Phase Transition of N-Isopropylacrylamide gel)

  • 박상보;민성기
    • 한국인쇄학회지
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    • 제21권1호
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    • pp.11-20
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    • 2003
  • Equilibrium swelling curves of N-isopropyl acrylamide(NIPA) gel and its ionized copolymer gels were obtained as a function of temperature. Discontinuous volume changes of the gels were observed. Phase transition temperature was increased with the ionized counter parts of the gels. Equilibrium swelling of ionized copolymer gel cylinder was found to depend strongly on their diameters. Crosslinking density of NIPA gel was adjusted by increasing N,N'-methylenebisacrylamide(BIS). Phase transition temperature was increased with the crosslinking density.

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Disc 전기영동법에 의한 수종 담수어 혈장 단백질의 분획 (Fractionation of Plasma Protein on the Several Fresh Water Fishes by Disc Electrophoresis)

  • 홍사욱;박성배
    • 약학회지
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    • 제22권1호
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    • pp.42-50
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    • 1978
  • The plasma proteins of fresh water fishes have been fractionated by disc electrophoresis in acrylamide gels utilized as an electrophoretic supporting medium. The species of fishes examined in this experiment were Anguilla japonica, Misgurnus mizolepis, Parasilurus asotus, Siniperca scherzeri, Pelteobagrus fulvidra, Carassius carassius, Cyprinus carpio, and Hemibarbus labeo, obtained in the Han River. Disc electrophoresis was performed as described by Ornstein and Davis. Gels and buffer solution were prepared by the method developed by W.J.Kim. The separation gels were 7% acrylamide gel. The fractionation of plasma proteins showed 13 bands in Anguilla japonica, 10 in Misgurnus mizolepis, 15 in Parasilurus asotus, 12 in Siniperca scherzeri, 11 in Pelteobagrus fulvidra, 13 in Carassius carassius, 9 in Cyprinus carpio, and 13 in Hemibarbus labeo. The patterns of plasma protein on the each species of fishes were different in the number of bands, ratio of contents, relative mobilities, and forms of fractionation.

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Alumina-Zirconia-Mullite 복합체의 상생성 및 치밀화 특성에 미치는 $\alpha-AI_2O_3$ Seeding 효과 (Effects of $\alpha-AI_2O_3$ Seeding on Phase Formation and Densification Characteristics of Alumina-Mullite-Zirconia Composites)

  • 조성목;장현명
    • 한국세라믹학회지
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    • 제31권12호
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    • pp.1475-1482
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    • 1994
  • Compositionally triphasic boehmite-silica-zirconia composite gels were prepared by a multiphasic sol-gel route. Phase-formation characteristics and densification behavior of the gel compacts were examined with and without $\alpha$-Al2O3 seeding. In the unseeded triphasic gels, both $\alpha$-Al2O3 and mullite crystallize simultaneously at 130$0^{\circ}C$. On the other hand, the $\alpha$-Al2O3 seeding selectively induces the formation of corundum phase ($\alpha$-Al2O3) at a significantly lower temperature (~110$0^{\circ}C$) and facilitates an epitaxial growth of $\alpha$-Al2O3 between 1100~130$0^{\circ}C$. The densification of alumina-mullite-zirconia composite (derived from the triphasic gels) was also enhanced by the $\alpha$-Al2O3 seeding, and this was attributed to the delayed crystallization of mullite in the $\alpha$-Al2O3 seeded gel.

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Using AP2RC & P1RB micro-silica gels to improve concrete strength and study of resulting contamination

  • Zahrai, Seyed Mehdi;Mortezagholi, Mohamad Hosein;Najaf, Erfan
    • Advances in concrete construction
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    • 제4권3호
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    • pp.195-206
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    • 2016
  • Today, application of additives to replace cement in order to improve concrete mixes is widely promoted. Micro-silica is among the best pozzolanic additives which can desirably contribute to the concrete characteristics provided it is used properly. In this paper, the effects of AP2RC and P1RB micro-silica gels on strength characteristics of normal concrete are investigated. Obtained results indicated that the application of these additives not only provided proper workability during construction, but also led to increased tensile, compressive and flexural strength values for the concrete during early ages as well as ultimate ones with the resulting reduction in the porosity lowering permeability of the micro-silica concrete. Furthermore, evaluation of microbial contamination of the mentioned gels showed the resultant contamination level to be within the permitted range.

Effect of Stereoregularity on the Properties of Syndiotacticity-Rich Ultrahigh Molecular Weight Poly(vinyl alcohol)/Dimethylsu1foxide/Water Gel

  • Park, Jin-Hyun;Lyoo, Won-Seok;Ko, Sohk-Won
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1998년도 가을 학술발표회논문집
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    • pp.13-16
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    • 1998
  • Poly(vinyl alcohol) (PVA) gels are easily formed via physical pathway. Most PVA solutions including PVA/water solution are well known to form thermally reversible gels at low temperature but these gels showed poor mechanical properties. In order to overcome this weak point, transparent crosslinked PVA hydrogels were prepared by electron beam irradiation or by chemical process with crosslinking agents or additives. (omitted)

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Proteome Approach as a Tool for the Efficient Separation of Seed Storage Proteins from Buckwheat

  • Cho, Seong-Woo;Kwon, Soo-Jeong;Roy, Swapan Kumar;Woo, Sun-Hee
    • 한국작물학회지
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    • 제60권1호
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    • pp.29-32
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    • 2015
  • Two-dimensional electrophoresis (2-DE) was executed to separate the seed storage proteins from the buckwheat. The proteins extracted from the whole seed proteins were better separated and observed in the use of lysis buffer. Using this method, the highly reproducible isoelectric focusing (IEF) can be obtained from polyacrylamide gels, and IEF from the polyacrylamide gel at all the possible pH range (5.0-8.0) was more easily separated than IPG (immobilized pH gradient) gels. The polyacrylamide gels in the first dimension in 2-DE was used to separate and identify a number of whole seed proteins in the proteome analysis. In this new apparatus using 2-DE, 27cm in length of plate coated with polyacrylamide gel was used and the experiment was further investigated under the various conditions.

Tunable Photonic Band Gap Materials and Their Applications

  • 강영종
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.261-261
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    • 2010
  • Photonic band gap (PBG) materials have been of great interest due to their potential applications in science and technology. Their applications can be further extended when PBG becomes tunable against various chemical and electrical stimuli. In recent, it was found that tunable photonic band gap materials can be achieved by incorporating stimuli-responsive smart gels into PBG materials. For example, the characteristic volume phase transition of gels in response to the various external stimuli including temperature, pH, ionic strength, solvent compositions and electric field were recently combined with the unique optical properties of photonic crystals to form unprecedented highly responsive optical components. Since these responsive photonic crystals are capable of reversibly converting chemical or electrical energy into characteristic optical signals, they have been considered as a good platform for label-free chemical or biological detection, actuators or optical switches as well as a model system for investigating gel swelling behavior. Herein, we report block copolymer photonic gels self-assembled from polystyrene-b-poly (2-vinyl pyridine) (PS-b-P2VP) block copolymers. In this talk, we are going to demonstrate that selective swelling of lamellar structure can be effectively utilized for fabricating PBG materials with extremely large tunability. Optical properties and their applications will be discussed.

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Determination of Frequency Independent Critical Concentration of Xathan and Carob Mixed Gels

  • Yoon, Won-Byong;Gunasekaran, Sundaram
    • Food Science and Biotechnology
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    • 제16권6호
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    • pp.1069-1071
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    • 2007
  • The frequency independent critical concentration (Cc) of xanthan and carob (X/C) mixed gel was determined based on the Winter-Chambon's theory. X/C mixed (X/C=1:1 ratio) gels were prepared from 0.1 to 1% of concentration. The linear viscoelastic properties, i.e., storage and loss modulus, of X/C mixed gel at $20^{\circ}C$ were measured by frequency sweep tests. The frequency independence of tangent function of phase angle (tan ${\delta}$) of X/C mixed gels was graphically determined from the intersection of the plot of phase angle against concentration at varied frequencies. The intersection (C=0.43%) was considered to be Cc of X/C mixed gel.

Effects of ${\beta}$-Conglycinin and Glycinin on Thermal Gelation and Gel Properties of Soy Protein

  • Kang, Il-Jun;Lee, Young-Sook
    • Food Science and Biotechnology
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    • 제14권1호
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    • pp.11-15
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    • 2005
  • Dynamic shear moduli of isolated soy protein solutions upon heating were measured to monitor gelation. Onsets of gelation coincide with onset temperatures of denaturation in glycinin and ${\beta}$-conglycinin solutions, whereas in isolated soy proteins, onset of gelation was above denaturation temperature of ${\beta}$-conglycinin with storage modulus increasing in two steps. The first increase in storage modulus of isolated soy proteins occurred at about $78.5^{\circ}C$, while the second increase started at about $93^{\circ}C$. Gel properties of soy protein gels having different proportions of glycinin and ${\beta}$-conglycinin were measured by compression-decompression test. ${\beta}$-conglycinin was responsible for gel elasticity. Glycinin significantly increased hardness, toughness, and fracturability of gels at high heating temperature near $100^{\circ}C$. Results reveal texture of soy protein gels can be controlled by regulating ratio of glycinin to ${\beta}$-conglycinin and heating temperature.