• Title/Summary/Keyword: $S_A/{\delta}_B$

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A Study on the Effect of Si Surface on Diamond Film Growth by AES (Diamond 박막 성장에 미치는 Si 표면 영향의 AES에 의한 연구)

  • Lee, Cheol-Ro;Sin, Yong-Hyeon;Im, Jae-Yeong;Jeong, Gwang-Hwa;Cheon, Byeong-Seon
    • Journal of the Korean Vacuum Society
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    • v.2 no.2
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    • pp.199-208
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    • 1993
  • The effect of nucleation free energy related to Si surface states on diamond film growth behavior has been studied. Ar first, the three kinds of diamond thin films (A, B, C) were deposited on various Si substrates (A-Si, B-Si, C-Si) whose surfaces were polished with 1 ${\mu}m$ diamond paste, 6 ${\mu}m$ Al_2O_3$ powder and 12 ${\mu}m$ Al_2O_3$ powder respectively. And then, relative nucleation free energy calculated is ${\Delta}G_{A-Si}<{\Delta}G_{B-Si}<{\Delta}G_{C-Si}$. Although there are some difference in grain size, shape and nucleated size, the thin films on A-Si and B-Si were diamond including a small amount of DLC which was confirmed by AES, SEM, XRD, and RHEED. Namely, the diamonds of films (B) were not nucleated in scratches but in dents and larger in grain size compare with the film (C) of which diamond sere nucleated not only scratches but also dents. And, the sphere diamond which is not general shape was grown on C-Si. After all, the sphere was turned out to be the diamond including much graphite as a result of the AES in situ depth profiling. Consequently, the diamond shape and quality grown on Si were Changed from the crystal which the (100) and (110) planes were predominent to the crystal in which (111) plane was predominent, and newt to sphere shape diamond including much graphite according as the nucleation free energy increases.

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A class of compact submanifolds with constant mean curvature

  • Jang, Changrim
    • Bulletin of the Korean Mathematical Society
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    • v.34 no.2
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    • pp.155-171
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    • 1997
  • Let $M^n$ be a connected subminifold of a Euclidean space $E^m$, equipped with the induced metric. Denoty by $\Delta$ the Laplacian operator of $M^n$ and by x the position vector. A well-known T. Takahashi's theorem [13] says that $\delta x = \lambda x$ for some constant $\lambda$ if and only if $M^n$ is either minimal subminifold of $E^m$ or minimal submanifold in a hypersphere of $E^m$. In [9], O. Garay studied the hypersurfaces $M^n$ in $E^{n+1}$ satisfying $\delta x = Dx$, where D is a diagonal matrix, and he classified such hypersurfaces. Garay's condition can be seen as a generalization of T.

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Study on Color Characteristics of a Dark State in the In-Plane Switching (IPS)Liquid Crystal Cell

  • Jung, B.S.;Baik, I.S.;Song, I.S.;Lee, S.H.;Kim, D.S.;Kim, K.J.;Ahn, B.C.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.453-456
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    • 2005
  • Color characteristics of a dark state in the IPS-mode depending on viewing direction have been studied. IPS-mode is having a little variation of $d{\Delta}n$ with viewing angle since the LC rotates in plane. However, this mode shows asymmetric light leakage and color characteristics with viewing angle in a dark state. This drawback can be overcome by optimized retardation value of TAC film, pre-tilt angle & $d{\Delta}n$ of LC.

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Hysteresis Loss in a $Sm_1Ba_2Cu_3O_{7-\delta}$ Coated Conductor under Simultaneously Applied Field and Current with Phase Differences (위상차를 갖고 변화하는 자기장과 전류가 동시에 가해진 $Sm_1Ba_2Cu_3O_{7-\delta}$ Coated Conductor의 자기이력 손실)

  • Lee, Sang-Moo;Jung, Ye-Hyun;Kwak, Ki-Sung;Rhee, Joon-Kyu;Yoo, Jae-Un;Youm, Do-Jun;Kim, Ho-Sup;Ha, Hong-Soo;Oh, Sang-Soo
    • Progress in Superconductivity
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    • v.10 no.2
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    • pp.92-98
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    • 2009
  • The magnetic field profiles near the surface of a $Sm_1Ba_2Cu_3O_{7-\delta}$ coated conductor(CC-tape) under magnetic field and current that were applied simultaneously with phase differences ${\phi}s$ were measured using scanning Hall probe method. Measurements were carried out along the elliptic load lines with $\phi=90^{\circ}\;and\;45^{\circ}$ for some $B_{peak},\;I_{peak}$ values. From the measured field profiles, sheet current density J(x, $B_a,\;I_a$) and magnetic flux density $B_0(x,\;B_a,\;I_a)$ profiles in the CC-tape were calculated. Using these J(x, $B_a,\;I_a$) and $B_0(x,\;B_a,\;I_a)$ profiles, we estimated the hysteresis energy loss Q in the CC-tape. The estimated Qs, together with our previous results for $\phi=0^{\circ}$ from [9], were compared with theoretical values based on Brandt's calculation.

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Effects of n-Alcohols on the Amino-Proton Chemical Shift and on the Hindered Rotation About N-C (S) Bond of Thioacetamide (Thioacetamide의 아미노 양성자의 화학적 이동과 N-C (S) 결합 주위의 부자유 회전에 미치는 n-알코올 용매 효과)

  • Jong-Ho Choi;Young-Sang Choi;Chang-Ju Yoon
    • Journal of the Korean Chemical Society
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    • v.33 no.2
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    • pp.149-155
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    • 1989
  • 1H-nmr chemical shifts and lineshapes of amino-protons of thioacetamide in n-alcohols were determined. The chemical shifts are discussed by the Reichardt's solvent polarity parameter, $E_T(30)$. The following relationship between ${delta}_{obs}\;and\;E_T(30)$ was obtained, ${\delta}_{obs}=a{\cdot}E_T(30)+b{\cdot}(E_T(30))_2$ where a is a characteristic constant for the protons of thioacetamide in n-alcohol solutions and b is a constant for the solute(TA)-solvent (n-alcohols) interactions. The barrier of the hindered rotation about the N-C(S) bond in TA was obtained by analysis of the lineshape of the amino-protons in TA. The behavior of the hindered rotation as well as chemical shifts of the amino-protons in TA has been found to be closely related to the $E_T(30)$ of n-alcohols.

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MOMENT CONVERGENCE RATES OF LIL FOR NEGATIVELY ASSOCIATED SEQUENCES

  • Fu, Ke-Ang;Hu, Li-Hua
    • Journal of the Korean Mathematical Society
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    • v.47 no.2
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    • pp.263-275
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    • 2010
  • Let {$X_n;n\;\geq\;1$} be a strictly stationary sequence of negatively associated random variables with mean zero and finite variance. Set $S_n\;=\;{\sum}^n_{k=1}X_k$, $M_n\;=\;max_{k{\leq}n}|S_k|$, $n\;{\geq}\;1$. Suppose $\sigma^2\;=\;EX^2_1+2{\sum}^\infty_{k=2}EX_1X_k$ (0 < $\sigma$ < $\infty$). We prove that for any b > -1/2, if $E|X|^{2+\delta}$(0<$\delta$$\leq$1), then $$lim\limits_{\varepsilon\searrow0}\varepsilon^{2b+1}\sum^{\infty}_{n=1}\frac{(loglogn)^{b-1/2}}{n^{3/2}logn}E\{M_n-\sigma\varepsilon\sqrt{2nloglogn}\}_+=\frac{2^{-1/2-b}{\sigma}E|N|^{2(b+1)}}{(b+1)(2b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2(b+1)}}$$ and for any b > -1/2, $$lim\limits_{\varepsilon\nearrow\infty}\varepsilon^{-2(b+1)}\sum^{\infty}_{n=1}\frac{(loglogn)^b}{n^{3/2}logn}E\{\sigma\varepsilon\sqrt{\frac{\pi^2n}{8loglogn}}-M_n\}_+=\frac{\Gamma(b+1/2)}{\sqrt{2}(b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2b+2'}}$$, where $\Gamma(\cdot)$ is the Gamma function and N stands for the standard normal random variable.

The Effective Isolation of a Mosquitocidal Bacteria, Bacillus thuringiensis Subsp. israelensis (모기 살충성 세균 B. thuringiensis subsp. israelensis의 효과적인 분리 방법)

  • 김광현;이광배;신두만
    • Journal of environmental and Sanitary engineering
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    • v.13 no.2
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    • pp.34-39
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    • 1998
  • For more convenient and rapidly isolation of Bacillus thuringiensis subsp. israelensis(Bti), 1) heat treatment spore forming bacteria, 2) growth in enrichment culture media for Bacillus sp. and 3) selection of bacteria producing a lecithinase for Bacillus thuringiensis subsp. israelensis, were performed. Spore forming bacteria were counted 4.8 $\times $ 10$^{8}$cells/g soil on NAPGCY media, 9.2 $\times $ 10$^{7}$cells/g soil on NA media, and 3.6 $\times $ 10$^{8}$cells/g soil on NAAC media, respectively. Bacteria producing only a lecithinase were reached at 25.2% on medium contained egg york, bacteria only producing a delta-endotoxin were reached at 23.2% by phase contrast microscope, and bacteria producing a lecithinase & a delta-endotoxin simultaneously were reached at 13.7%. Bacillus thuringiensis which producing a lecithinase and a delta-endotoxin simultaneously among bacteria producing a lecithinase, were reached at 56.5%; A half of Bacillus thuringiensis was produced a delta-endotoxin, but not produced a lecithinase. Among 8 isolates of Bacillus thuringiensis, two strain of Bti which has a mosquito-cidal toxin, were detected by PCR using a specific primer of $\delta $-endotoxin gene from Bti.

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Behavior of the Vortex Flux in a Polycrystalline $Y_1Ba_2Cu_3O_{7-\delta}$Superconductor in a Rotational Experiment (회전실험에서의 다결성 $Y_1Ba_2Cu_3O_{7-\delta}$ 초전도체내의 vorterx flux의 거동)

  • 박성재;김용석;김채옥
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.9
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    • pp.752-757
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    • 1998
  • Rotational Magnetization-vector measurements have been performed on a polycrystalline $Y_1Ba_2Cu_3O_{7-\delta}$ sample in field-cooled condition at 4.2 K. The experimental results show that vortex flux density(B) consists of 3 groups :(1) a weak pinning part ($B_w$) which stays at a fixed angle relative to the magnetic field f(H) ; (2) a strong pining part($B_s$) which rotates rigidly with the sample and has same magnitude with the sample rotation, and(3) and intermediated pining part ($B_i$) which rotates rigidly with the sample, but whose magnitude changes with the sample rotation Our results have been explained in terms of a distribution in the strength of the vortex pinning torque and a repulsive intervortex torque.

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Multi-objective Optimization of Pedestrian Wind Comfort and Natural Ventilation in a Residential Area

  • H.Y. Peng;S.F. Dai;D. Hu;H.J. Liu
    • International Journal of High-Rise Buildings
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    • v.11 no.4
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    • pp.315-320
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    • 2022
  • With the rapid development of urbanization the problems of pedestrian-level wind comfort and natural ventilation of tall buildings are becoming increasingly prominent. The velocity at the pedestrian level ($\overline{MVR}$) and variation of wind pressure coefficients $\overline{{\Delta}C_p}$ between windward and leeward surfaces of tall buildings were investigated systematically through numerical simulations. The examined parameters included building density ρ, height ratio of building αH, width ratio of building αB, and wind direction θ. The linear and quadratic regression analyses of $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were conducted. The quadratic regression had better performance in predicting $\overline{MVR}$ and $\overline{{\Delta}C_p}$ than the linear regression. $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were optimized by the NSGA-II algorithm. The LINMAP and TOPSIS decision-making methods demonstrated better capability than the Shannon's entropy approach. The final optimal design parameters of buildings were ρ = 20%, αH = 4.5, and αB = 1, and the wind direction was θ = 10°. The proposed method could be used for the optimization of pedestrian-level wind comfort and natural ventilation in a residential area.

Molecular Cloning of a Delta-class Glutathione S-transferase Gene from Bombus ignitus

  • Park, Jong-Hwa;Yoon, Hyung-Joo;Gui, Zhong Zheng;Jin, Byung-Rae;Sohn, Hung-Dae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.18 no.1
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    • pp.28-32
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    • 2009
  • We describe here the cloning and characterization of a cDNA encoding the glutathione S-transferase (GST) from the bumblebee Bombus ignitus. The Delta-class B. ignitus GST (BiGSTD) gene spans 1668 bp and consists of four introns and five exons that encode 216 amino acid residues with a calculated molecular weight of approximately 24561 Da and a pI of 8.03. The N-terminal domain of BiGSTD has a conserved Ser residue, as well as conserved Lys, Pro, Glu, Ser and Tyr residues that are involved in the GSH-binding site of GST. The BiGSTD showed 60% protein sequence identity to the Bombyx mori GSTT1, 58% to Musca domestica GST, 57% to Drosophila melanogaster GST, and 55% to Anopheles gambiae GST1. BiGSTD was close to the insect-specific Delta class of GSTs in a phylogenetic tree. Northern blot analysis showed that BiGSTD is highly expressed in the fat body and midgut, and less so in the muscles of B. ignitus worker bees.