• Journal of the Korean Chemical Society
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• v.11 no.3
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• pp.100-104
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• 1967

The systems of aromatic amines such as aniline, N,N-dimethylaniline and N,N-diethylaniline with iodine or iodine monochloride in carbon tetrachloride have been examined spectrophotometrically. The results indicate the formation of one to one molecular complexes. The equilibrium constants obtained at room temperature for formation of the complexes are as follows: $C_6H_5NH_2{\cdot}I_2\;2.05$, $C_6H_5N(CH_3)_2{\cdot}I_2\;15.2$, $C_6H_5N(C_2H_5)_2{\cdot}I_2\;35.5$, $C_6H_5NH_2{\cdot}ICl\;18.5$, $C_6H_5N(CH_3)_2{\cdot}ICl\;25.6$, and $C_6H_5N(C_2H_5)_2\;42.0$ l $mole^{-1}$.

• Journal of the Korean Chemical Society
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• v.52 no.3
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• pp.249-256
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• 2008

3-Acetyl/Formyl 4-hydroxy-2H(1)-benzopyran-2-one on treatment with malonitrile and ethyl cyanoacetate yielded 1,1-dicyano-2-[4/-hydroxy-2/H(1)-benzopyran-2/-one-3/-yl] ethene/propene 2a-h and ethyl-2-cyano-3-[4/-hydroxy-2/H (1)-benzopyran-2/-one-3/-yl] propenoate/butenoate 3a-h respectively. The 1,3 dipolar reaction of 2a-h with NaN3 gave the tetrazole derivative 4a-h. 3a-h on cyclization with PPA gave 3-cyano-2H,5H-pyrano [3, 2-c] benzopyran-2,5-diones 5a-h which on 1,3 dipolar reaction with NaN3 to gave 3-(1/H-tetrazol-5/-yl)-2H,5H-pyrano[3, 2-c] benzopyran-2,5-diones 6a-h. The structures of the compounds have been established on the basis of the spectral and analytical data. All the compounds were screened for their antimicrobial activities and have been found to exhibited significant antibacterial activities. Compounds 2h and 4h showed the activity 50g/mL.

• Journal of Power System Engineering
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• v.18 no.1
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• pp.51-56
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• 2014

In this paper, the performance of the $CO_2-C_2H_6-N_2$ cascade liquefaction cycle with respect to temperature differences in the LNG heat exchangers is analyzed theoretically using HYSYS software and then compared the COP(coefficient of performance) of the cascade liquefaction cycles using $C_3H_8-C_2H_4-C_1H_4$ and $CO_2-N_2O-N_2$. In comparison of COP of three cycles, the cascade liquefaction cycles using $C_3H_8-C_2H_4-C_1H_4$ showed the highest COP. And the liquefaction cycle using $CO_2-C_2H_6-N_2$ and $CO_2-N_2O-N_2$ presented the second and third highest COP, respectively. In case of COP, the $C_3H_8-C_2H_4-C_1H_4$ cascade liquefaction cycle yields better COP. But, in terms of the environment and maintain, it is confirmed that the cascade liquefaction cycle using $CO_2-C_2H_6-N_2$ provides favorable characteristics.

• Journal of the Korean Chemical Society
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• v.19 no.6
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• pp.403-407
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• 1975

The rate constant for the $N_2H_4-Br_2$ reaction has been measured in sulfuric acid media by direct mixing method and chronopotentiometric method. The former gave 105 mole-1 l sec-1 whereas the latter 103 mole-1 l sec-1. It has been inferred that the former represents the rate constant for $N_2H_4-Br_2$ {\rightarrow} $N_2H_2$ and the latter for $N_2H_2+Br_2$ {\rightarrow} X. When the concentrations of KBr and $H_2SO_4$ are both high, drastic reduction of rate constant has been observed.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.1-5
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• 1997

The crystal structure of the title compound consists of discrete 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium, $C_{16}H_{19}N_2$, and tosylate, $C_7H_7SO_3$, dimer. The 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium molecule has a trans conformation at the central C=C double bond: the dihedral angle between the phenyl and the pyridyl rings is $5.7(2)^{\circ}$ and the whole molecule is planar within $0.138(8){\AA}$. Tosylate molecules display hydrogen-bonded dimers with the O-H...O distances of 2.855(9) and $2.899(8){\AA}$, respectively. The shortest intermolecular contact is the distance $3.10(1){\AA}$ between O(3) and C(16).

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.671-679
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• 2010

The geometrical parameters and binding energies of the benzene ion-water complex [$C_6H_6^+-(H_2O)_n$(n=1-5)] have been investigated using ab initio (MP2) and density functional theory (DFT) with large basis sets. The harmonic vibrational frequencies and IR intensities are also determined to confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the binding energies. The predicted binding energy of 8.6 kcal/mol for $C_6H_6^+-(H_2O)$ at the MP2/aug-cc-pVTZ level of theory is in excellent agreement with recent experimental result of $8.5{\pm}1$ kcal/mol.

• Bulletin of the Korean Mathematical Society
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• v.52 no.1
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• pp.105-123
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• 2015

Let $f_{\beta}=h_{\beta}+\bar{g}_{\beta}$ and $F_a=H_a+\bar{G}_a$ be harmonic mappings obtained by shearing of analytic mappings $h_{\beta}+g_{\beta}=1/(2isin{\beta})log\((1+ze^{i{\beta}})/(1+ze^{-i{\beta}})\)$, 0 < ${\beta}$ < ${\pi}$ and $H_a+G_a=z/(1-z)$, respectively. Kumar et al. [7] conjectured that if ${\omega}(z)=e^{i{\theta}}z^n({\theta}{\in}\mathbb{R},n{\in}\mathbb{N})$ and ${\omega}_a(z)=(a-z)/(1-az)$, $a{\in}(-1,1)$ are dilatations of $f_{\beta}$ and $F_a$, respectively, then $F_a\tilde{\ast}f_{\beta}{\in}S^0_H$ and is convex in the direction of the real axis, provided $a{\in}[(n-2)/(n+2),1)$. They claimed to have verified the result for n = 1, 2, 3 and 4 only. In the present paper, we settle the above conjecture, in the affirmative, for ${\beta}={\pi}/2$ and for all $n{\in}\mathbb{N}$.

• Journal of the Korean Mathematical Society
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• v.43 no.4
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• pp.783-801
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• 2006

Let A be the mod p Steenrod algebra for p an arbitrary odd prime and S the sphere spectrum localized at p. In this paper, some useful propositions about the May spectral sequence are first given, and then, two new nontrivial homotopy elements ${\alpha}_1{\jmath}{\xi}_n\;(p{\geq}5,n\;{\geq}\;3)\;and\;{\gamma}_s{\alpha}_1{\jmath}{\xi}_n\;(p\;{\geq}\;7,\;n\;{\geq}\;4)$ are detected in the stable homotopy groups of spheres, where ${\xi}_n\;{\in}\;{\pi}_{p^nq+pq-2}M$ is obtained in [2]. The new ones are of degree 2(p - 1)($p^n+p+1$) - 4 and 2(p - 1)($p^n+sp^2$ + sp + (s - 1)) - 7 and are represented up to nonzero scalar by $b_0h_0h_n,\;b_0h_0h_n\tilde{\gamma}_s\;{\neq}\;0\;{\in}\;Ext^{*,*}_A^(Z_p,\;Z_p)$ in the Adams spectral sequence respectively, where $3\;{\leq}\;s\;<\;p-2$.

• Honam Mathematical Journal
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• v.26 no.4
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• pp.379-389
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• 2004

Given operators X and Y acting on a Hilbert space ${\mathcal{H}}$, an interpolating operator is a bounded operator A such that AX = Y. An interpolating operator for n-operators satisfies the equation $AX_i=Y_i$, for $i=1,2,{\cdots},n$. In this article, we obtained the following : Let ${\mathcal{H}}$ be a Hilbert space and let ${\mathcal{L}}$ be a commutative subspace lattice on ${\mathcal{H}}$. Let X and Y be operators acting on ${\mathcal{H}}$. Then the following statements are equivalent. (1) There exists an operator A in $Alg{\mathcal{L}}$ such that AX = Y, A is positive and every E in ${\mathcal{L}}$ reduces A. (2) sup ${\frac{{\parallel}{\sum}^n_{i=1}\;E_iY\;f_i{\parallel}}{{\parallel}{\sum}^n_{i=1}\;E_iX\;f_i{\parallel}}}:n{\in}{\mathbb{N}},\;E_i{\in}{\mathcal{L}}$ and $f_i{\in}{\mathcal{H}}<{\infty}$ and <${\sum}^n_{i=1}\;E_iY\;f_i$, ${\sum}^n_{i=1}\;E_iX\;f_i>\;{\geq}0$, $n{\in}{\mathbb{N}}$, $E_i{\in}{\mathcal{L}}$ and $f_i{\in}H$.

• Bulletin of the Korean Mathematical Society
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• v.36 no.4
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• pp.701-706
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• 1999

A characterization of geodesic spheres in the simply connected space forms in terms of the ratio of the Gauss-Kronecker curvature and the (usual) mean curvature is given: An immersion of n dimensional compact oriented manifold without boundary into the n + 1 dimensional Euclidean space, hyperbolic space or open half sphere is a totally umbilicimmersion if the mean curvature $H_1$ does not vanish and the ratio $H_n$/$H_1$ of the Gauss-Kronecker curvature $H_n$ and $H_1$ is constant.