• Bulletin of the Korean Chemical Society
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• v.1 no.2
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• pp.62-68
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• 1980

Ultraviolet spectrophotometric investigations have been carried out the systems of monoalkylbenzene with iodine in carbon tetrachloride. The results reveal the formation of one to one molecular complexes. The equilibrium constants for these complexes of representative monosubstituted benzene reveal the following order of increasing stability: benzene < methyl- < ethyl- < n-propyl-benzene. The value of ${\Delta}H$, ${\Delta}G$, and ${\Delta}S$ for interaction of a number of monoalkyl substituted benzene with iodine has been determinated. In general, as ΛH becomes increasingly negative, corresponding decreases in ${\Delta}G$ and ${\Delta}S$ values are observed, and these variation are linear. The thermodynamic constants become increasingly negative with increasing monoalkyl substitution of the aromatic donor nucleus. The complex bond is therefore weak, and its formation is accompanied by relatively small entropy changes.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.156-161
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• 1998

We have measured changes of the non-stoichiometry, $\Delta\delta$, in Fe-doped nicked oxide , by thermogravimetry for four iron fractions, x=0.01, 0.031, 0.057 and 0.10, and three temperatures, T=1273, 1373 and 1473 K. The obtained data can be modelled by a defect structure in which substitutional trivalent iron ions, FeNi, are compensated by cation vacancies, $V_{Ni}$", and (4:1)-clusters. These clusters consist of tetravalent interstitial iron, $Fe_i\;^4$

• Bulletin of the Korean Mathematical Society
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• v.53 no.6
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• pp.1795-1804
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• 2016

Let $M^n$, $2{\leq}n{\leq}6$ be a complete noncompact hypersurface immersed in ${\mathbb{H}}^{n+1}$. We show that there exist two certain positive constants 0 < ${\delta}{\leq}1$, and ${\beta}$ depending only on ${\delta}$ and the first eigenvalue ${\lambda}_1(M)$ of Laplacian such that if M satisfies a (${\delta}$-SC) condition and ${\lambda}_1(M)$ has a lower bound then $H^1(L^2(M))=0$. Excepting these two conditions, there is no more additional condition on the curvature.

• Bulletin of the Korean Mathematical Society
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• v.49 no.6
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• pp.1131-1145
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• 2012

The purpose of this paper is to use an appropriate variational framework to discuss the boundary value problem with p-Laplacian type operators $$\{({\alpha}(t,x^{\Delta}(t)))^{\Delta}-a(t){\phi}_p(x^{\sigma}(t))+f({\sigma}(t),x^{\sigma}(t))=0,\;{\Delta}-a.e.\;t{\in}I\\x^{\sigma}(0)=0,\\{\beta}_1x^{\sigma}(1)+{\beta}_2x^{\Delta}({\sigma}(1))=0,$$ where ${\beta}_1$, ${\beta}_2$ > 0, $I=[0,1]^{k^2}$, ${\alpha}({\cdot},x({\cdot}))$ is an operator of $p$-Laplacian type, $\mathbb{T}$ is a time scale. Some sufficient conditions for the existence of constant-sign solutions are obtained.

• Journal of applied mathematics & informatics
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• v.36 no.3_4
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• pp.213-229
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• 2018

In this work, we establish oscillation of the second order sublinear neutral delay dynamic equations of the form:$$(r(t)((x(t)+p(t)x({\tau}(t)))^{\Delta})^{\gamma})^{\Delta}+q(t)x^{\gamma}({\alpha}(t))+v(t)x^{\gamma}({\eta}(t))=0$$ on a time scale T by means of Riccati transformation technique, under the assumptions $${\displaystyle\smashmargin{2}{\int\nolimits^{\infty}}_{t_0}}\({\frac{1}{r(t)}}\)^{\frac{1}{\gamma}}{\Delta}t={\infty}$$, and ${\displaystyle\smashmargin{2}{\int\nolimits^{\infty}}_{t_0}}\({\frac{1}{r(t)}}\)^{\frac{1}{\gamma}}{\Delta}t$ < ${\infty}$, for various ranges of p(t), where 0 < ${\gamma}{\leq}1$ is a quotient of odd positive integers.

• Journal of applied mathematics & informatics
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• v.30 no.5_6
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• pp.1005-1021
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• 2012

This work is concerned with oscillation of the second order sublinear neutral delay dynamic equations of the form $$\(r(t)\;\((y(t)+p(t)y(a(t)))^{\Delta}\)^{\gamma}\)^{\Delta}+q(t)y^{\gamma}({\beta}(t))=0$$ on a time scale $\mathcal{T}$ by means of Riccati transformation technique, under the assumptions $\int^{\infty}_{t_0}\(\frac{1}{r(t)}\)^{\frac{1}{\gamma}}$ ${\Delta}t={\infty}$ and $\int^{\infty}_{t_0}\(\frac{1}{r(t)}\)^{\frac{1}{\gamma}}$ ${\Delta}t$ < ${\infty}$, where 0 < ${\gamma}{\leq}1$ is a quotient of odd positive integers.

• Electrical & Electronic Materials
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• v.5 no.3
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• pp.278-283
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• 1992

123 초전도체에 마그네틱 모멘트가 큰 Ni불순물을 도핑하여 제작한 $Y_{1}$ Ba(C $u_{2.9}$ $N_{0.1}$) $O_{7-{\delta}}$ 초전도체의 X-ray diffraction pattern, susceptibility, 온도변화등에 따른 전류-전압관계, 임계온도 등에 대하여 연구하였다. 제작된 시료는 매우 뚜렷한 orthorhombic 피크를 가진 123상을 나타내고 있었다. N=0.1의 시료에서는 적은 양의 Ni 불순물과 단면적인 무정형상태의 잘 반응된 YBa(Cu, Ni)$_{3}$ $O_{7-{\delta}}$의 orthorhombic구조를 나타내고 있다. 전반적인 실험 결과로 부터 Ni는 Y-Ba-Cu-O 초전도 시스템에서 초전도에 중요한 역할을 담당하지 않는다는 결론을 얻었다.얻었다.다.

• Journal of the Korean Chemical Society
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• v.8 no.4
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• pp.142-146
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• 1964

The author proposed an equation of fading rate, expressed as ${\Delta}E$=${\Delta}E_{1{\infty}}({{1-e^{-k}}_1}^t)+k_2t$, where ${\Delta}E$=fading of dye (colour difference of N.B.S. unit), ${\Delta}E_{1{\infty}}$=extremity value of fading of molecularly dispersed dye, $k_1$, $k_2$=constants, t=exposure (hours). The validity of above equation, which is connected with the state of dye in fibre, was confirmed by experimental in a range of 2-3 colour fading in grey scale value for assessing change in colour visually, except the case of increasing the fading rate with the time resulted from the break-down of dye particles through the heat effect of light; it was also discussed about possiblity of evaluating of fastness to light of dye in early stage.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.1
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• pp.41-48
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• 2002

This paper presents a 18-mW, 2.5-㎓ fractional-N frequency synthesizer with l-bit $4^{th}$-order interpolative delta-sigma ($\Delta{\;}$\sum$)modulator to suppress fractional spurious tones while reducing in-band phase noise. A fractional-N frequency synthesizer with a quadruple prescaler has been designed and implemented in a $0.5-\mu\textrm{m}$ 15-GHz $f_t$ BiCMOS. Synthesizing 2.1 GHzwith less than 200 Hz resolution, it exhibits an in-band phase noise of less than -85 dBc/Hz at 1 KHz offset frequency with a reference spur of -85 dBc and no fractional spurs. The synthesizer also shows phase noise of -139 dBc/Hz at an offset frequency of 1.2 MHz from a 2.1GHz center frequency.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.239-246
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• 1985

The equilibria of chemical reaction between [Cu(dl-trans-[14]-diene)]$^{2+}$ and L$^{n-}$(S$_2$O$_3^{2-}$, SCN$^-$, I$^-$, NO$_2^-$) ions were studied by the spectrophotometric method in the range of 15 to 35$^{\circ}C$ and 1 to 1500bar. The equilibrium constants(K) for L$^{n-}$ = S$_2$O$_3^{2-}$, SCN$^-$, I$^-$ and NO$_2^-$ ions at 25$^{\circ}C$ and 1500bar were 3.0, 1.9, 0.6 and 0.5, respectively. The values of K decreased with increasing pressure and temperature. From the temperature effect on equlibrium constant, the thermodynamic parameters(${\Delta}G^{\circ}$, ${\Delta}H^{\circ}$, ${\Delta}S^{\circ}$) of reaction were evaluated and the reactions of [Cu(dl-trans-[14]-diene)]2+ ion with S$_2$O$_3^{2-}$, SCN$^-$ and I$^-$ except NO$_2^-$ ion were exothermic. The volume changes of reaction(${\Delta}$V) had positive values for all the used anions. The values of ${\Delta}$V in cm$^3$/mole for S$_2$O$_3^{2-}$ ion at 1,500, 1,000 and 1,500bar were 26, 22, 19 and 16, and those for S$_2$O$_3^{2-}$, SCN$^-$, I$^-$ and NO$_2^-$ ions at atmospheric pressure 26, 30, 64 and 45, respectively. Bonding character between Cu(Ⅱ)-complex ion and L$^{n-}$ was discussed by comparing both the equlibrium constants experimentally determined and those calculated according to Fuoss's ion-pair equation in case of S$_2$O$_3^{2-}$ ion.