• 대한화학회지
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• 제39권7호
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• pp.572-577
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• 1995

아세토니트릴 용매계에서 aryl 치환(Z)-benzoate류와 아민류의 반응속도를 15, 25, 및 35 $^{\circ}C$에서 분광학적 방법으로 구했다. 2차 반응속도 상수로부터 Hammett $\rho$값, Bronsted ${\beta}$값, 및 활성화 parameter를 구했으며 이들값과 M-O-F-J diagram 등의 해석으로부터 본 반응은 $S_AN$ 메카니즘으로 진행됨을 알 수 있었다.

• Nuclear Engineering and Technology
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• 제11권1호
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• pp.21-27
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• 1979

TRIGA Mark II 원자로심에서 반응율을 측정하여 중성자 spectrum parameter인 상대적인 증성자 온도 T$^{n}$ 과 열외중성자 지수 (equation omitted)를 얻기 위해 해석하였다. 측정은 경수 환경하에 있는 central thimble과 F2위치에서 수행되었다. 상대적인 중성자 온도는 Lu과 Mn의 방사화율로 표시되며 열외중성자 지수는 Au와 Mn의 반응율에 의go서 측정된다. 이들 검출박의 상대적인 ${\gamma}$-에너지는 multichannel analyzer에 의해서 분석되었다. 실험 결과는 이론적인 계산치와 비교 평가되었다.

• 한국세라믹학회지
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• 제31권12호
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• pp.1545-1551
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• 1994

Various kinetic parameters of the nucleation and crystallization in anorthite glass (CaO.Al2O3.2SiO2) were calculated by nonisothermal differential thermal analysis. Base glass and glass with TiO2 were prepared by melting. In base glass, the temperature where nucleation can occur ranges from 85$0^{\circ}C$ to 9$25^{\circ}C$ and the temperature for maximum nucleation was 900$\pm$5$^{\circ}C$. In glass with TiO2, the nucleation temperature range was 800~875$^{\circ}C$ and the maximum nucleation temperature was 850$\pm$5$^{\circ}C$. Kissinger equation, Bansal equation, and modified Ozawa equation were used for calculating activation energy for crystallization, Ec. The results showed the same activation energies for both glasses with and without TiO2 in the different equations. The shape of maximum exotherm peak and Ozawa equation were used for Avrami exponent, n. The n value for each glass was 2, indicating that each glass crystallized primarily by bulk crystallization.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.111-116
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• 2014

The kinetics and mechanism of oxidation of sulfanilic acid by N-chloro-p-toluene sulfonamide (chloramine-T) have been studied in acid medium. The species of chloramine-T were analysed on the basis of experimental observations and predominantly reactive species was taken into account for proposition of most plausible reaction mechanism. The derived rate law (1) conforms to such a mechanism. $$-\frac{d[CAT]}{dt}=\frac{kK_1[RNHCl][SA]}{K_1+[H^+]}$$ (1) All kinetic parameters were evaluated. Activation parameters such as energy and entropy of activation were calculated to be $(61.67{\pm}0.47)kJmol^{-1}$ and $(-62.71{\pm}2.48)kJmol^{-1}$ respectively employing Eyring equation.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2989-2994
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• 2013

The solvolysis rate constants of 3,4- (1) and 3,5-dimethoxybenzoyl (2) chlorides were measured in various pure and binary solvents at $25.0^{\circ}C$, and studied by application of the extended Grunwald-Winstein (G-W) equation, kinetic solvent isotope effect in methanolysis and activation parameters. The solvolysis of 1 was interpreted as the unimolecular pathway due to a predominant resonance effect from para-methoxy substituent like 4-methoxybenzoyl chloride (3), while that of 2 was evaluated as the dual mechanism, with unimolecular or bimolecular reaction pathway according to the character of solvent systems (high electrophilic/nucleophilic) chosen, caused by the inductive effect by two meta-methoxy substituents, no resonance one. In the solvolyses of 1 and 2 with two $-OCH_3$ groups, the resonance effect of para-methoxy substituent is more important to decide the mechanism than the inductive effect with other corresponding evidences.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.80-87
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• 2024

This paper focuses on improving accuracy in constrained computing settings by employing the ReLU (Rectified Linear Unit) activation function. The research conducted involves modifying parameters of the ReLU function and comparing performance in terms of accuracy and computational time. This paper specifically focuses on optimizing ReLU in the context of a Multilayer Perceptron (MLP) by determining the ideal values for features such as the dimensions of the linear layers and the learning rate (Ir). In order to optimize performance, the paper experiments with adjusting parameters like the size dimensions of linear layers and Ir values to induce the best performance outcomes. The experimental results show that using ReLU alone yielded the highest accuracy of 96.7% when the dimension sizes were 30 - 10 and the Ir value was 1. When combining ReLU with the Adam optimizer, the optimal model configuration had dimension sizes of 60 - 40 - 10, and an Ir value of 0.001, which resulted in the highest accuracy of 97.07%.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.99-102
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• 2002

The BSCCO superconductor materials of using Self-propagating High-temperature Synthesis (SHS) were studied. Mechano-chemical activation - as a pre-treatment of the reactants mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product. In this paper as an effort for fabricating the SHSed BSCCO superconductor powder SHS method was considered to application in the synthesis of superconducting materials.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.421-424
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• 2011

본 연구에서는 열분석법을 이용하여 혼합 액체연료의 수치해석에 필요한 여러 가지 인자를 측정하였다. 이러한 열분석법에는 열중량 분석방법(TGA, Thermo-Gravimetric Analyzer)과 시차 주사열량 측정법(DSC, Differential Scanning Calorimetry)이 있다. 열중량 분석방법을 통한 비등온 실험(non-isothermal experimental) 결과를 토대로 Freeman Carroll의 수학적인 후처리 방법을 이용하여 미지의 액체연료의 구성 성분에 대한 동역학적 변수인 활성화 온도와 반응차수로 각각 6128.2 K와 1.4를 얻었다. 그 외 다양한 수학적 처리 방법에 따른 동역학적 변수의 값을 구해보았고, 계산 결과는 처리방법에 따라 약간의 차이를 보였다.

• 분석과학
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• 제14권4호
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• pp.1075-1081
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• 2001

기기중성자방사화 분석법은 핵 분석기술의 대표적인 방법으로 비파괴-동시 다원소분석의 장점과 함께 절대측정값에 의해 정량 할 수 있다는 특징을 갖고 있다. 최근에는 정확도와 편의성을 만족할 수 있는 $k_0$-정량법을 사용한 기기중성자방사화 분석법이 세계적으로 일반화되고 있다. 본 연구에서는 $k_0$-법의 적용을 위하여 이 방법의 전체적인 개념의 소개와 함께 $k_0$-파라미터를 측정하고자 하였다. 이를 위하여 $k_0$-법의 개념이해와 정량에 필요한 인자들의 정의 및 파라미터인 $Q_0$(${\alpha}$)와 f 값을 결정하기 위한 수식과 실험적 측정방법 등을 요약하였고 중성자조사공에 따라 특성 값을 갖는 ${\alpha}$와 f 값을 하나로 연구용원자로의 방사화분석용 조사공(NAA#1)에서 측정하여 $k_0$-법의 도입을 위한 기반을 마련하였다.

• 한국자동차공학회논문집
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• 제21권6호
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• pp.183-194
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• 2013

Liquid urea based SCR has been used in the market to reduce NOx in the exhaust emission of the diesel engine vehicle. This system has several problems at low temperature, which are freezing below $-12^{\circ}C$, solid deposit formation in the exhaust, and difficulties in dosing system at exhaust temperature below $200^{\circ}C$. Also, it is required complicated exhaust packaging equipment and mixer due to supply uniform ammonia concentration. In order to solve these issues, solid urea, ammonium carbonate, and ammonium carbamate are selected as ammonia sources for the application of solid SCR. In this paper, basic research on reaction rate of three ammonia-transporting materials was performed. TGA (Thermogravimetric Analysis) and DTA (Differential Thermal Analysis) tests for these materials are carried out for various heating conditions. From the results, chemical kinetic parameters such as activation energy and frequency factor are obtained from the Arrhenius plot. Additionally, from test results of DSC (Differential Scanning Calorimeter) for these materials, chemical kinetic parameters using the Kissinger method are calculated. Activation energies of solid SCR from this experiment are compared with proper data of literature study, then obtained data of this experiment are used for the design of reactor and dosing system for candidate vehicle.