• Journal of the Korean Chemical Society
• /
• v.20 no.2
• /
• pp.111-117
• /
• 1976

The configuration and conformation of methyl benzamidoxime have been studied from extended Huckel molecular orbital calculations.The results show that the E-configuration of the C=N double bond is favored compared with that of Z-configuration with the sp-conformation of the C-N bond rotamers, but Z-configuration is more stable with the ap-conformation of the C-N bond rotamers. The conformation of C-N bond with equal configuration of C=N bond and equal conformation of N-O bond, sp-form is favored, but the conformation of N-O bond with equal configuration and equal conformation of C-N bond ap-form is more stable. The major part of the stabilization energies can be accounted for by the electrostatic energies between the atoms involved.

• East Asian mathematical journal
• /
• v.16 no.2
• /
• pp.169-174
• /
• 2000

We give an easy proof that ${\phi}(z)=\frac{z^2_1}{1-z^2_2}$ induces the bounded composition operator $C_{\phi}:\mathcal{B}{\rightarrow}{\bigcap}H^p(B_2)$ defined by $C_{\phi}f=f\;o\;{\phi}$.

• Journal of the Korean Mathematical Society
• /
• v.39 no.1
• /
• pp.119-126
• /
• 2002

For a stationary multivariate linear process of the form X$_{t}$ = (equation omitted), where {Z$_{t}$ : t = 0$\pm$1$\pm$2ㆍㆍㆍ} is a sequence of stationary linearly positive quadrant dependent m-dimensional random vectors with E(Z$_{t}$) = O and E∥Z$_{t}$∥ $^2$< $\infty$, we prove a central limit theorem.theorem.

• Kyungpook Mathematical Journal
• /
• v.53 no.3
• /
• pp.459-465
• /
• 2013

Let $p(z)$ be an analytic function defined on the open unit disk D and $p(0)=1$. Condition ${\beta}$ in terms of complex numbers D and real E with -1 < E < 1 and ${\mid}D{\mid}{\leq}1$ is determined such that $1+{\beta}{\prec}\frac{1+Dz}{1+Ez}$ implies $p(z){\prec}\sqrt{1+z}$. Furthermore, the expression $1+\frac{{\beta}zp^{\prime}(z)}{p(z)}$ and $1+\frac{{\beta}zp^{\prime}(z)}{p^2(z)}$ are considered in obtaining similar results.

• Journal of the Korean Chemical Society
• /
• v.57 no.3
• /
• pp.382-388
• /
• 2013

The present paper focuses on the synthesis, characterization and application of nanophotocatalyst for degradation of quinalphos and monocrotophos. Novel heterostructured ZnO/$TiO_2$ photocatalyst ($Z_9T$) was prepared and characterized with X-ray diffraction (XRD), SEM and UV-vis diffuses reflectance spectroscopy. The average crystalline size of synthesized $Z_9T$ was found to be 21.48 nm. The pesticides were degraded in the presence of nanophotocatalysts i.e., $TiO_2$, ZnO, $TiO_2$/ZnO mixed in various proportions and heterostructured nanophotocatalyst synthesized by Sol-Gel method. The batch experiments were performed by adding photocatalyst to 100 ml of pesticide solution and suspension was subjected to irradiation under UV light. In case of mixed catalyst, the maximum degradation of monocrotophos and quinalphos has been observed when ZnO and $TiO_2$ were in the ratio of 7:3 and 8:2 respectively. The degradation efficiency with synthesized heterostructured nanophotocatalyst ($Z_9T$) was found to be comparable with $TiO_2$.

• Korean Journal of Materials Research
• /
• v.11 no.3
• /
• pp.197-202
• /
• 2001

M $g_{1-x}$ Z $n_{x}$O thin films with various composition x of ZnO were fabricated by a RF magnetron sputtering method, which is expected to improve the electro-optical properties of the conventional MgO protective layer for AC-PDP. Test panels with the $Mg_{1-x}$Z $n_{x}$O protective layer have been fabricated in order to investigate the effects of ZnO doping on the electrical characteristics of devices such as the discharge voltages and the memory gain. Experimental results revealed that test panels with the $Mg_{1-x}$Z $n_{x}$O(x=0.5at%) protective layer show lower firing and sustain voltages than those seen in panels with MgO protective layer by 20V. resulting in an increasement of the memory coefficient. In addition, it was found that test panels with the $Mg_{1-x}$Z $n_{x}$O protective layer show higher discharge intensity, i. e., higher plasma density, compared with panels with MgO protective layer.ve layer.layer.

• Advances in materials Research
• /
• v.5 no.2
• /
• pp.93-105
• /
• 2016

KNN-based ceramics modified with small amounts of $Bi_4Zr_3O_{12}$ (BiZ) has been synthesized using high-throughput experimentation (HTE). The results from X-ray diffraction show that for samples with base composition $(K_{0.5}Na_{0.5})NbO_3$ (KNN), the phase present changes from orthorhombic to pseudo-cubic with more than 0.2 mol% BiZ addition; for samples with base composition $(K_{0.48}Na_{0.48}Li_{0.04})(Nb_{0.9}Ta_{0.1})O_3$ (KNNLT), the phase present changes from a mixture of orthorhombic and tetragonal symmetry to pseudo-cubic with more than 0.4 mol % while for samples with base composition $(K_{0.48}Na_{0.48}Li_{0.04})(Nb_{0.86}Ta_{0.1}Sb_{0.04})O_3$ (KNNLST), the phase present is tetragonal with <0.3 mol% BiZ addition and transforms to pseudo-cubic with more dopant addition. The microstructures of the samples show that addition of BiZ decreases the average grain size and increases the volume of pores at the grain boundaries. The values of dielectric constant for KNN and KNNLT compositions increase slightly with BiZ addition while that for KNNLST decreases gradually with BiZ addition. The dielectric loss values are between 0.02 and 0.04 for KNNLT and KNNLST compositions while they are ~ 0.05 for KNN samples. The resistivity values increases with BiZ addition and values in the range of $10^{10}{\Omega}cm$ and $10^{12}{\Omega}cm$ are obtained. The piezoelectric charge coefficient ($d{^*}_{33}$) is highest for KNNLST samples and decreases gradually from ~400 pm/V to ~100 pm/V with BiZ addition.

• Speech Sciences
• /
• v.15 no.3
• /
• pp.31-38
• /
• 2008

The aim of this study was to find how English vowels affect the pronunciation of English sibilants /$d_3,\;{_3}$, z/ by Korean learners of English. Fifteen nonsense syllables composed by five vowels /a, e, i, o, u/ were pronounced six times by twelve Korean learners of English. Test scores were measured from the scoreboard made by a speech training software program, which was designed for English pronunciation practice and improvement. Results show that 1) the subjects had the lowest scores in /a_a/ position, and 2) subjects had lower scores in the /i_i/ position than in /e_e/, /o_o/ and /u_u/ positions when they pronounced $/d_3/,\;/{_3}/$, and /z/ in their respective inter-vocalic position. This study found that for the group studied Korean learners of English have more difficulty in pronouncing sibilants in /a_a/ and /i_i/ positions than in the other positions.

• Honam Mathematical Journal
• /
• v.27 no.2
• /
• pp.301-315
• /
• 2005

Let $\{A_u,\;u=0,\;1,\;2,\;{\cdots}\}$ be a sequence of coefficient matrices such that ${\sum}_{u=0}^{\infty}{\parallel}A_u{\parallel}<{\infty}$ and ${\sum}_{u=0}^{\infty}\;A_u{\neq}O_{m{\times}m}$, where for any $m{\times}m(m{\geq}1)$, matrix $A=(a_{ij})$, ${\parallel}A{\parallel}={\sum}_{i=1}^m{\sum}_{j=1}^m{\mid}a_{ij}{\mid}$ and $O_{m{\times}m}$ denotes the $m{\times}m$ zero matrix. In this paper, a functional central limit theorem is derived for a stationary m-dimensional linear process ${\mathbb{X}}_t$ of the form ${\mathbb{X}_t}={\sum}_{u=0}^{\infty}A_u{\mathbb{Z}_{t-u}}$, where $\{\mathbb{Z}_t,\;t=0,\;{\pm}1,\;{\pm}2,\;{\cdots}\}$ is a stationary sequence of linearly positive quadrant dependent m-dimensional random vectors with $E({\mathbb{Z}_t})={{\mathbb{O}}$ and $E{\parallel}{\mathbb{Z}_t}{\parallel}^2<{\infty}$.

• Natural Product Sciences
• /
• v.15 no.4
• /
• pp.192-197
• /
• 2009

Chemical investigation of the aerial parts of Artemisia iwayomogi has afforded five glycoside compounds. Their chemical structures were characterized by spectroscopic methods to be turpinionoside A (1), (Z)-3-hexenyl O-${\alpha}$-arabinopyranosyl-(1${\rightarrow}$6)-O-${\beta}$-D-glucopyranoside (2), (Z)-5'-hydroxyjasmone 5'-O-${\beta}$-Dglucopyranoside (3), (-)-syringaresinol-4-O-${\beta}$-D-glucopyranoside (4), and methyl 3,5-di-O-caffeoyl quinate (5). All of them were isolated for the first time from Artemisia species. The effect of compounds 1 - 5 on the function of osteoblastic MC3T3-E1 cells was examined by checking the cell viability, alkaline phosphatase (ALP) activity, collagen synthesis, and mineralization. Turpinionoside A (1) significantly increased the function of osteoblastic MC3T3-E1 cells. Cell viability, ALP activity, collagen synthesis, and mineralization were increased up to 117.2% (2 ${\mu}M$), 110.7% (0.4 ${\mu}M$), 156.0% (0.4 ${\mu}M$), and 143.0 % (2 ${\mu}M$), respectively.