• 제목/요약/키워드: $k-{\omega}\

검색결과 3,473건 처리시간 0.034초

천연 올레인산 기반 폴리아미드계 TPEs 단량체 합성 (Synthesis of Monomers for Polyamide-type TPEs from Oleic Acid)

  • 고무현;김현수;김현정;신나라;유동원;김영규
    • Elastomers and Composites
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    • 제48권1호
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    • pp.24-29
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    • 2013
  • 식물성 오일로부터 추출한 물질을 기반으로 하여 열가소성 탄성체(thermoplastic elastomer, TPE) 중에서도 뛰어난 물성을 가진 것으로 잘 알려진 폴리아미드계 TPE(polyamide-type TPE, TPAE)의 단량체 합성공정을 개발하였다. 대다수의 식물성 오일에 함유되어 있는 불포화 지방산으로 잘 알려진 올레인산을 사용하여 TPAE의 단량체 6종($C_9$, $C_{10}$, $C_{11}$ ${\omega}$-amino acid 와 ${\alpha}$, ${\omega}$-dicarboxylic acid)을 좋은 수율로 합성하였다.

Identification of ${\omega}$-Aminotransferase from Caulobacter crescentus and Sitedirected Mutagenesis to Broaden Substrate Specificity

  • Hwang, Bum-Yeol;Ko, Seung-Hyun;Park, Hyung-Yeon;Seo, Joo-Hyun;Lee, Bon-Su;Kim, Byung-Gee
    • Journal of Microbiology and Biotechnology
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    • 제18권1호
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    • pp.48-54
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    • 2008
  • A putative ${\omega}$-aminotransferase gene, cc3143 (aptA), from Caulobacter crescentus was screened by bioinformatical tools and overexpressed in E. coli, and the substrate specificity of the ${\omega}$-aminotransferase was investigated. AptA showed high activity for short-chain ${\beta}$-amino acids. It showed the highest activity for 3-amino-n-butyric acid. It showed higher activity toward aromatic amines than aliphatic amines. The 3D model of the ${\omega}$-aminotransferase was constructed by homology modeling using a dialkylglycine decarboxylase (PDB ID: 1DGE) as a template. Then, the ${\omega}$-aminotransferase was rationally redesigned to increase the activity for 3-amino-3-phenylpropionic acid. The mutants N285A and V227G increased the relative activity for 3-amino-3-phenylpropionic acid to 3-amino-n-butyric acid by 11-fold and 3-fold, respectively, over that of wild type.

ESTIMATES OF THE BERGMAN KERNEL FUNCTION ON PSEUDOCONVEX DOMAINS WITH COMPARABLE LEVI FORM

  • Cho, Sang-Hyun
    • 대한수학회지
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    • 제39권3호
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    • pp.425-437
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    • 2002
  • Let $\Omega$ be a smoothly bounded pseudoconvex domain in $C^{n}$ and let $z^{0}$ $\in$b$\Omega$ a point of finite type. We also assume that the Levi form of b$\Omega$ is comparable in a neighborhood of $z^{0}$ . Then we get precise estimates of the Bergman kernel function, $K_{\Omega}$(z, w), and its derivatives in a neighborhood of $z^{0}$ . .

AN ANALOGUE OF WIENER MEASURE AND ITS APPLICATIONS

  • Im, Man-Kyu;Ryu, Kun-Sik
    • 대한수학회지
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    • 제39권5호
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    • pp.801-819
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    • 2002
  • In this note, we establish a translation theorem in an analogue of Wiener space (C[0,t],$\omega$$\phi$) and find formulas for the conditional $\omega$$\phi$-integral given by the condition X(x) = (x(to), x(t$_1$),…, x(t$_{n}$)) which is the generalization of Chang and Chang's results in 1984. Moreover, we prove a translation theorem for the conditional $\omega$$\phi$-integral.l.

NONTRIVIAL SOLUTIONS FOR AN ELLIPTIC SYSTEM

  • Nam, Hyewon;Lee, Seong Cheol
    • Korean Journal of Mathematics
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    • 제23권1호
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    • pp.153-161
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    • 2015
  • In this work, we consider an elliptic system $$\left{\array {-{\Delta}u=au+bv+{\delta}_1u+-{\delta}_2u^-+f_1(x,u,v) && in\;{\Omega},\\-{\Delta}v=bu+cv+{\eta}_1v^+-{\eta}_2v^-+f_2(x,u,v) && in\;{\Omega},\\{\hfill{70}}u=v=0{\hfill{90}}on\;{\partial}{\Omega},}$$, where ${\Omega}{\subset}R^N$ be a bounded domain with smooth boundary. We prove that the system has at least two nontrivial solutions by applying linking theorem.

$L_q$ estimation on the least energy solutions

  • Pahk, Dae-Hyeon;Park, Sang-Don
    • 대한수학회지
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    • 제32권2호
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    • pp.329-339
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    • 1995
  • Let us consider the Neumann problem for a quasilinear equation $$ (I_\varepsilon) {\varepsilon^m div($\mid$\nabla_u$\mid$^{m-2}\nabla_u) - u$\mid$u$\mid$^{m-2} + f(u) = 0 in \Omega {\frac{\partial\nu}{\partial u} = 0 on \partial\Omega. $$ where $1 < m < N, N \geq 2, \varepsilon > 0, \Omega$ is a smooth bounded domain in $R^n$ and $\nu$ is the unit outer normal vector to $\partial\Omega$.

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WEAK INVERSE SHADOWING AND Ω-STABILITY

  • Zhang, Yong;Choi, Taeyoung
    • 충청수학회지
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    • 제17권2호
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    • pp.137-145
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    • 2004
  • We give characterization of ${\Omega}$-stable diffeomorphisms via the notions of weak inverse shadowing. More precisely, it is proved that the $C^1$ interior of the set of diffeomorphisms with the weak inverse shadowing property with respect to the class $\mathcal{T}_h$ coincides with the set of ${\Omega}$-stable diffeomorphisms.

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LOWER HOUNDS ON THE HOLOMORPHIC SECTIONAL CURVATURE OF THE BERGMAN METRIC ON LOCALLY CONVEX DOMAINS IN $C^{n}$

  • Cho, Sang-Hyun;Lim, Jong-Chun
    • 대한수학회보
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    • 제37권1호
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    • pp.127-134
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    • 2000
  • Let $\Omega$ be a bounded pseudoconvex domain in$C^{n}$ with smooth defining function r and let$z_0\; {\in}\; b{\Omega}$ be a point of finite type. We also assume that $\Omega$ is convex in a neighborhood of $z_0$. Then we prove that all the holomorphic sectional curvatures of the Bergman metric of $\Omega$ are bounded below by a negative constant near $z_0$.

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A NOTE ON ZEROS OF BOUNDED HOLOMORPHIC FUNCTIONS IN WEAKLY PSEUDOCONVEX DOMAINS IN ℂ2

  • Ha, Ly Kim
    • 대한수학회보
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    • 제54권3호
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    • pp.993-1002
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    • 2017
  • Let ${\Omega}$ be a bounded, uniformly totally pseudoconvex domain in ${\mathbb{C}}^2$ with the smooth boundary b${\Omega}$. Assuming that ${\Omega}$ satisfies the negative ${\bar{\partial}}$ property. Let M be a positive, finite area divisor of ${\Omega}$. In this paper, we will prove that: if ${\Omega}$ admits a maximal type F and the ${\check{C}}eck$ cohomology class of the second order vanishes in ${\Omega}$, there is a bounded holomorphic function in ${\Omega}$ such that its zero set is M. The proof is based on the method given by Shaw [27].

DENSE SETS IN WEAK STRUCTURE AND MINIMAL STRUCTURE

  • Modak, Shyamapada
    • 대한수학회논문집
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    • 제28권3호
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    • pp.589-596
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    • 2013
  • This paper is an attempt to study and introduce the notion of ${\omega}$-dense set in weak structures and the notion of m-dense set in minimal structures. We have also investigate the relationships between ${\omega}$-dense sets, $m$-dense sets, ${\sigma}({\omega})$ sets, ${\pi}({\omega})$ sets, $r({\omega})$ sets, ${\beta}({\omega})$ sets, m-semiopen sets and $m$-preopen sets. Further we give some representations of the above generalized sets in minimal structures as well as in weak structures.