• 한국응용과학기술학회지
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• 제12권2호
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• pp.85-92
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• 1995

The rate constant of the nucleophilic addition of 1-propanethiol to ${\alpha}-phenyl-N-iso-propylnitrone$ derivatives were determined at various pH and a rate equation which can be applied over wide pH range is obtained. Final product of the addition reaction was ${\alpha}-thiopropyl-p-phenylbenzylideneamine$. Base on the rate equation, general base effect, substituent effect and final product, plausible mechanism of addition reaction have been proposed. Below pH 3.0, the reaction was initiated by the addition of 1-propanthiol, and in the range of pH 3.0-10.0, proceeded by the competitive addition of 1-propanethiol and propanethiolate. Above the pH 10.0, the reaction proceeded through the addition of propanethiolate.

• 한국추진공학회지
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• 제16권5호
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• pp.47-57
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• 2012

고에너지 물질의 연소 현상을 해석하기 위하여 반드시 필요한 반응속도식과 이를 구성하고 있는 미 정상수를 결정하는 이론적 방법을 제안하였다. 개선된 I&G 모델은 기존의 반응속도식이 갖던 문제점들을 효과적으로 극복하면서 동시에 중요한 물리적 의미를 내포하는 형태로 제안되었다. 이는 공극붕괴(void collapse)로 인한 hotspot의 생성을 의미하는 점화 모델과 폭굉(detonation)으로의 천이를 의미하는 화염 발달 모델의 합으로 구성되어 있다. 또한 함께 소개된 이론적 모델은 고에너지 물질의 수치해석 기법인 Hydrocode를 사용하기 전에 미정상수 $b,\;G,\;x,\;I$를 결정함으로써 특정 고에너지 물질의 연소 특성을 규명하는데 사용된다. 이론적 방법은 기존의 고에너지 물질의 연소 시험을 모사한 수치해석적 방식보다 효율적이고 정확도가 높은 결과를 제공하므로 진일보 된 방법이라고 할 수 있다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.331-341
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• 2012

고에너지 물질의 연소 현상을 해석하기 위하여 반드시 필요한 반응속도식과 이를 구성하고 있는 미정상수를 결정하는 이론적 방법을 제안하였다. 개선된 I&G 모델은 기존의 반응속도식이 갖던 문제점들을 효과적으로 극복하면서 동시에 중요한 물리적 의미를 내포하는 형태로 제안되었다. 이는 공극붕괴(void collapse)로 인한 hotspot의 생성을 의미하는 점화 모델과 폭굉(detonation)으로의 천이를 의미하는 화염 발달 모델의 합으로 구성되어 있다. 또한 함께 소개된 이론적 모델은 고에너지 물질의 수치해석 기법인 Hydrocode를 사용하기 전에 미정상수 b, G, x, I를 결정함으로써 특정 고에너지 물질의 연소 특성을 규명하는데 사용된다. 이론적 방법은 기존의 고에너지 물질의 연소 시험을 모사한 수치해석적 방식보다 효율적이고 정확도가 높은 결과를 제공하므로 진일보 된 방법이라고 할 수 있다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
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• pp.134-137
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• 2001

The cure kinetics of a cycloalipatic epoxy / anhydride / Co(II) system for a no-flow underfill encapsulant, has been studied by using a differential scanning calorimetry(DSC) under isothermal and dynamic conditions over the temperature range of $160^{\circ}C ~220^{\circ}C$. The kinetic analysis was carried out by fitting dynamic/isothermal heating experimental data to the kinetic expressions to determine the reaction parameters, such as order of reaction and reaction constants. Diffusion-controlled reaction has been observed as the cure conversion increases and successfully analyzed by incorporating the diffusion control term into the rate equation. The prediction of reaction rates by the model equation corresponded well to experimental data at all temperature.

• 대한화학회지
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• 제18권6호
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• pp.423-429
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• 1974

$ {\alpha}$-Cyano-$ {\beta}$-piperonylacrylic acid(CPA)에 대한 hydorogen cyanide의 진핵성 첨가 반응속도 상수를 측정하여 넓은 pH범위에서 잘 맞는 반응 속도식을 구하였다. 이 식에 의하면 pH3이하에서는 CPA에 대해 hydrogen cyanide분자의 첨가 반응이 일어나지만 pH6에서 8사이는 hydrogen cyanide가 $ {\alpha}$-cyano-$ {\beta}$-piperonyl acrylate ion에 첨가함을 알수 있고, 또 pH 3과 6사이에서는 이들 두 반응이 경쟁적으로 일어난다. 그리고 pH9이상에서는 $ {\alpha}$-cyano-$ {\beta}$-piperonyl acrylate ion에 cyanide ion이 첨가하는 반응이 일어나며 pH3에서 9까지의 모든 복잡한 반응 메카니즘도 이식으로 충분히 설명할 수 있음을 알았다.

• 오토저널
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• 제5권1호
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• pp.32-44
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• 1983

In case of $K_{Imax}$ < $K_{Iscc}$, the corrosion fatigue of high strength steel in 0.1N $H_{2}$S $O_{4}$ solution and 3.5% salt water is as follows. 1. The fatigue life shortens in order of 3.5% salt water and 0.1N $H_{2}$S $o_{4}$ solution. 2. The fatigue crack growth rate in air is obtained as the following equation. (dc/dN)$_{atr}$=7.23*10$^{-6}$ (.DELTA. K)$^{2.23}$ 3. The corrosion fatigue crack growth rate in environment is divided into three regions, that is, First Region, Second Region and Third Region from the small cyclic stress intensity. 4. The formation rate of the active surface on metal is slower than the mechano-chemical reaction rate in First Region. The crack growth rate depends on time and the cyclic stress intensity and is expressed as the following equation. (dc/dN)$_{I}$=C(/DELTA. K)$^{\delta}$ 5. The formation rate of the active surface is faster than the mechano-chemical reaction rate in Second Region and the synergistic effect by stress and corrosion becomes slow. In case the fatigue load is large, we have the critical crack growth rate which is not related to the cyclic stress intensity. 6. The corrosion crack growth rate by the mechano-chemical reaction is the same in $H_{2}$S $O_{4}$ solution and salt water, so Hydrogen accelerates the crack growth. 7. The environment has no effect on the corrosion fatigue crack growth rate in Third Region. 8. In First Region and Second Region, dimple is observed on the fatigue fracture surface in 0.1N $H_{2}$S $O_{4}$ solution. 9. The striation is observed in any environment as in air in Third Region and its interval approximately coincide with the crack growth rate.ate.e.e.

• 한국응용과학기술학회지
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• 제12권2호
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• pp.93-98
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• 1995

The rate constant of Nucleophilic addition of sodium thiophenoxide to nitrone were determined by UV Spectrophotometry and a rate equation which can be applied over wide pH range was obtained. Base on the rate equation, general base effect, substituent effect and final product, plausible mechanism of addition reaction have been proposed. Blow pH 3.0, the reaction was initiated of thiophenol, and in the range of pH $3.0{\sim}10.0$, proceeded by the competitive addition of thiophenol and thiophenoxide anion. Above the pH 10.0, the reaction proceeded through the addition of a thiophenoxide anion.

• 한국미생물·생명공학회지
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• 제13권1호
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• pp.33-39
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• 1985

The effects of initial concentration, flow rate, and recycle ratio on the removal efficiency of phenol were studied in a tapered fluidized bed reactor packed with activated carbon which was attached with Candida tropicalis. The optimum conditions of Candida tropicalis were showed that pH was 7.0 and temperature was $30^{\circ}C$, and the specific growth rate of Candida tropicalis was satisfied with the Monod equation up to 500 mg/L of phenol, and beyond it the inhibition of substrate was found. According to the increases of initial concentration and flow rate, the removal efficiency was decreased, as the recycle ratio was increased, the removal efficiency was increased. In the case of flow rate of 10mL/sec and the recycle ratio of 2, the removal efficiency was 90% above for the all of initial concentration. The removal rate of phenol was the first order reaction in this system, and the rate equation of reaction was as follows.

• 한국재료학회지
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• 제5권6호
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• pp.667-672
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• 1995

DGEBA (diglycidyl ether of bisphenol A )/MDA(4,4'-methylene dianiline)/SN(succinonitrile)계와 DGEBA/MDA/SN/HQ(hydroquinone)계의 경화반응 속도론을 Kissinger equation 및 Fractional life 법에 의해 85~15$0^{\circ}C$에서 DSC를 이용하여 연구하였다. 경화반응 온도가 높아짐에 따라 반응속도는 증가하는 반면, 반응차수는 거의 일정하였다. 또한 촉매로 HQ를 첨가한 계가 첨가하지 않은 계보다 반응속도는 크게 증가했으며, 활성화 에너지 값은 약 20% 정도 감소하였다 또한, 경화반응 시작온도는 3$0^{\circ}C$ 정도 낮아졌다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.283-286
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• 2012

The analytical model determining the unknown parameters of reaction rate equation which is necessary to simulate the combustion phenomena of energetic materials is proposed. The relationship between detonation velocity and size effect of energetic materials is derived from simplified JWL++ model. Theoretical model is used to investigate the combustion characteristics of certain energetic materials before running Hydrocode by pre-determination of unknown parameter, b. When b=0.8, the behavior of HANFO gunpowder is in the form of concave-up and ANFO explosives has the concave-down form in case of b=1.5. The analytical model provides efficient and highly accurate results rather than previous method which simulated the unconfined-rate-stick via the numerical means.