• 대한화학회지
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• 제35권2호
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• pp.111-118
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• 1991

기체 상태의 오존(0.5 torr)과 이산화황간의 반응속도를 연구하였다. 이산화황은 7∼22 torr 의 압력범위에서 90∼155$^{\circ}$C의 온도영역에서 반응시켰다. 오존과 이산화황의 반응속도는 이산화탄소와의 반응보다 빨리 진행되었다. 오존과 이산화황의 반응속도식은 -d(O$_3 )/dt = k _0 (SO _2 )(M)(O _3)+2k _1(SO_2 )(O _3$)였다. 이 속도식의 첫 항은 3분자 반응으로 낮은 온도에서 우세하게 진행되었으며, 속도상수 k$_0 =(9.35{\pm}8.6){\times}10^9e^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$)이다. 속도식의 두번째 항은 2분자 열분해 반응으로부터 유도된 주된 반응으로 속도상수 k$_1=(1.53{\pm}1.5){\times}10^{11}e^{-22.7 kcal/RT}$이다. 전 반응차수는 주로 2차 반응이며 3차 반응과 복합반응으로 진행되었다.

• 환경위생공학
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• 제17권1호
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• pp.69-74
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• 2002

This study explored for treatment processes by investigating the treatment efficiency and reaction mechanism through oxidation reaction using UV and $O_3$ as oxidant in compensate the wastewater containing nitrobenzene that is non biodegradable organic. Also by modeling these reactions, we try to step explanation of optimum reaction rate and reaction mechanism as the development of the computer program predictable the reaction rate by modeling the reaction. By using this model, after kinetic constant for each reaction from an experimental data is made an optimization and for hardly contribute to reaction rate in reaction kinetic equation is made an ignorance and suppose the simplified reaction mechanism, examined the propriety of computer simulation model and simplified reaction mechanism by comparing and inspecting the reaction kinetic constant and masstransfer coefficient. An investigation results for destructional treatment of nitrobenzene in the wastewater as non-biddegradable organic using UV, $O_3{\;}O_2{\;}H_2O_2-UV$ as oxidant.

• 한국환경과학회지
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• 제13권1호
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• pp.37-40
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• 2004

In this study, the decomposition of gas-phase TCE, Benzene and Toluene, in air streams by direct UV Photolysis and UV/TiO$_2$ process was studied. For direct UV Photolysis, by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene and Benzene in this work were determined to be 0.00392s$\^$-l/, 0.00230s$\^$-1/ and 0.00126s$\^$-1/, respectively. And the adsorption constant K of TCE, Toluene and Benzene in this work were determined to be 0.0519 mol$\^$-l/ ,0.0313mo1$\^$-1/ and 0.0084mo1$\^$-1/, respectively. For UV/TiO$_2$ system by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene, and Benzene in this work were determined to be 5.74g/$\ell$$.$min, 3.85g/$\ell$$.$min, and 1.18g/$\ell$$.$min, respectively. And the catalyst adsorption constant K of TCE, Toluene, and Benzene in this work were determined to be 0.0005㎥/mg, 0.0043㎥/mg and 0.0048㎥/mg, respectively.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2269-2273
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• 2012

Pseudo-first-order rate constants $k_{amine}$ have been measured spectrophotometrically for the reactions of benzyl 4-pyridyl carbonate 6 with a series of alicyclic secondary amines in $H_2O$ at $25.0^{\circ}C$. The plots of $k_{amine}$ vs. [amine] curve upward, indicating that the reactions proceed through a stepwise mechanism with two intermediates, a zwitterionic tetrahedral intermediate $T^{\pm}$ and its deprotonated form $T^-$. This contrasts to the report that the corresponding reactions of benzyl 2-pyridyl carbonate 5 proceed through a forced concerted pathway. The $k_{amine}$ values for the reactions of 6 have been dissected into the second-order rate constant $Kk_2$ and the thirdorder rate constant $Kk_3$. The Br${\o}$nsted-type plots are linear with ${\beta}_{nuc}=0.94$ and 1.18 for $Kk_2$ and $Kk_3$, respectively. The $Kk_2$ for the reaction of 6 is smaller than the second-order rate constant $k_N$ for the corresponding reaction of 5, although 4-pyridyloxide in 6 is less basic and a better nucleofuge than 2-pyridyloxide in 5.

• 대한환경공학회지
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• 제29권7호
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• pp.846-851
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• 2007

본 연구는 PCP를 UV, $UV/H_2O_2$, $Fe^{2+}$, $Fe^{2+}/H_2O_2$, 그리고 $UV/Fe^{2+}/H_2O_2$의 공정을 이용하여 처리할 저 각각 공정의 처리효율을 비교하여 각 반응의 결합에 의한 개선 효과와 분해 기전을 규명한 연구이다. 실험의 결과 UV 반응에 $H_2O_2$의 첨가에 따라 약 13배 정도의 유사 일차 반응 속도의 증가를 보였으며, $Fe^{2+}$ 단독 반응에 비해 180 mM과 16 mM의 $H_2O_2$의 첨가는 각각 4배와 7.25배의 반응 속도 증가를 보였다. 또한 $Fe^{2+}/H_2O_2$의 반응에 비해 UV를 조사한 반응의 경우 약 3.1배의 반응 속도의 개선을 보였다. 이러한 반응속도의 증가는 각 반응에서 생성되는 OH 라디칼의 생성과 밀접한 관계가 있었다. $Fe^{2+}/H_2O_2$ 반응에서 일어나는 슬러지 침전 반응은 UV를 조사함으로서 상당부분 제거가 가능하였다.

• 공업화학
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• 제10권6호
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• pp.885-888
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• 1999

본 연구에서는 $Na_2B_4O_7{\cdot}10H_2O/Na_2B_4O_7{\cdot}5H_2O$ 반응계의 열분해 탈수반응에 의한 반응속도상수를 결정하고 반응계의 재현성 및 화학축열재의 반복사용에 따른 내구성을 검토하였다. 반응계의 열분해 탈수반응의 차수는 1차이었고, 열분해 탈수 반응속도는 수증기의 분압차에 정비례하였다. 반응계의 반응속도상수는 약 0.27이었고, 반응속도상수와 반응차수에 대한 반응의 재현성이 우수하였다. 또한 화학축열재의 내구성은 연속적으로 반복 사용하여도 활성변화는 ${\pm}5%$ 범위 내에 있었다.

• 동력기계공학회지
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• 제21권2호
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• pp.14-19
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• 2017

The corrosion characteristics of Al-Si-Mg alloy were investigated in $O_2$ and $H_2S/H_2$ environments at high temperature. The weight gain and the reaction rate constant of the Al-Si-Mg alloy were measured in the oxygen and hydrogen sulfide environments at 773K. The weight gain of Al-Si-Mg alloy was showed parabolic increase in the oxygen and hydrogen sulfide environments. The reaction rate constants were confirmed to be $1.45{\times}10^{-4}mg^2cm^{-4}sec^{-2}$ in the oxygen environment and $6.19{\times}10^{-4}mg^2cm^{-4}sec^{-2}$ in the hydrogen sulfide environment respectively. As a result of XPS analysis on the specimen surface, $Al_2O_3$ and MgO compounds were detected in oxygen environment and $Al_2(SO_4)_3$ sulfate was detected in the hydrogen sulfide environment. Corrosion rate of Al-Si-Mg alloy was about 4.3 times faster in hydrogen sulfide environment than oxygen environment.

• 약학회지
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• 제19권2호
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• pp.101-110
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• 1975

p-Chloronitrobenzene(substrate) and p-nitrophenetole (product) were quantitatively analyzed to know the degree of extent of reaction in the process of time. The calibration curve was prepared by the internal satndard method in gaschromatography. 2,6-Dimethyl-naphthalene was used as internal standard. The rate constant(k), the reaction velocity in various concentrations of NaOH altered, and the formation of byproducts(azo-compound and p-nitrophenol) with the amounts of MnO$_{2}$ and NaOH altered, were studied. From the results of these of MnO$_{2}$ and NaOH altered, were studied. From the results of these experiments, this reaction was second order and the rate constant was k=10.3 $\times$ 10$^{-3}$ mole$^{-21$. When p-chloronitrobenaene 1 pt. NaOH 0.56pts. MnO$_{2}$ 0.5pts. and ethanol 25 pts-were reacted about 10 hours, p-nitrophenetole was nearly quantitatively obtained without byproducts.

• Journal of Photoscience
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• 제11권2호
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• pp.77-81
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• 2004

Deoxygadusol (DO) and structurally related mycosporine-like amino acids, i.e. mycosporine glycine (MO) and mycosporine taurine (MT), were isolated from phytoplankton Prorocentrum micans and studied for the reactivity toward singlet oxygen. These water-soluble compounds with a cyclohexenone chromophore were all shown to be highly effective in quenching singlet oxygen ($^1$ $O_2$), with the efficiencies being significantly larger compared with histidine, a well-known $^1$ $O_2$ quencher. The $^1$ $O_2$ reaction rate constant ( $k_{Q}$) of DG was determined to be 5.4 ${\times}$ 10$^{7}$ $M^{-1}$ $s^{-1}$ by a steady state method based on competitive inhibition of rubrene oxidation. The feasibility of this method was confirmed by estimating the $k_{Q}$ values for MG and two other quenchers, furfuryl alcohol and 1,4-diazabicyclo [2,2,2]octane, and comparing with those values determined by the time-resolved $^1$ $O_2$ decay method in the previous work.ork.

• 대한화학회지
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• 제36권5호
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• pp.644-651
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• 1992

기체상태의 오존(0.5torr)과 삼산화황간의 반응속도를 연구하였다. 69∼150${\circ}C$ 온도영역에서, 삼산화황은 6∼12 torr의 압력 범위에서 반응시켰다. 오존과 삼산화황의 반응속도는 $CO_2$가 단독으로 존재하고 있을 때의 오존의 반응속도보다 더욱 빨리 진행되었다. 오존과 삼산화황의 분자 반응에 대한 명백한 증거는 발견되지 않았고 빠른 반응속도는 $O_3\;＋\;HX\;{\rightarrow}\;OH\;＋\;O_2\;＋\;X$로 시작되는 연쇄반응을 일으키게 하는 $SO_3$ 반응물에 포함된 불순물(HX) 때문인 것 같고 또한 삼산화황은 더 큰 충돌직경을 가지고 있어 그것이 오존의 열적분해를 더욱 더 빠르게 하는 이유인 것으로 사료된다. 제안된 오존과 삼산화황의 실험속도식; $[-d(O_3)/dt]\;=\;k_a(SO_3)(O_3)\;＋\;k_b(O_3)^{3/2}$과 반응속도 상수 ; $k_a(M^{-1} s^{-1})\;=\;(1.55\;{\pm}\;0.67)\;{\times}\;105\;e-{(9.270 {\pm}0.43)kcal/RT}$을 얻었다..