• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.222-232
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• 2009

In this study, the real site test conditions were considered and applied to suggest the improved test method for geosynthetics chemical resistance. For this, index and performance tests were done to specify and regulate the more approached test method. Accelerated model by Arrhenius equation was applied to interpretate the experimental data. Through analysis and comparison the overall experimental results, we could suggest the possibility and setup the advanced chemical resistance test method for geosynthetics.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권5호
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• pp.191-195
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• 2005

This paper presents an assessment method in integrity of the windings in cast resin molded transformers by using vertical analysis of thermal distribution. The proposed method is to compare the temperature distribution in a sound specimen with that in the faulted specimen with a layer to layer short circuit. Temperature distribution was acquired by an infrared thermography system, and the Arrhenius equation was adopted to the accelerated test. The proposed method can be used to detect the failures in the transformers.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권1호
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• pp.65-76
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• 2013

In order to assess the reliability of engine mount for a vehicles, life test model and procedure are developed. By using this method, failure mechanism and life distribution are analyzed. The main results are as follows; i) the main failure mechanism is degradation failure of engine mount rubber by fatigue failure at dynamic load. ii) temperature is a second factor to affect a failure. iii) the life distribution of engine mount module is fitted well to Weibull life distribution and the shape parameter is 18.4 and the accelerated life model of that is fitted well to Arrhenius model.

• 전기학회논문지
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• 제62권6호
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• pp.881-885
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• 2013

In this paper, we present a deterioration judgment model of urban rail power equipment using driving history, the frequency and number of failures. In addition, we have developed a deterioration judgment program based on the derived failure rate. A deterioration judgment model of power equipments on metro system was designed to establish how much environmental factors, such as thermal cycling, humidity, overvoltage and partial discharge. The deterioration rate of the transformers followed the Arrhenius log life versus reciprocal Kelvin temperature (hotspot temperature) relation. The deterioration judgment program is linked to the online condition monitoring system of urban railway system. The deterioration judgment program is based on the user interface it is possible to apply immediately to the urban rail power equipment.

• International Journal of Railway
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• 제6권1호
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• pp.13-25
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• 2013

Railpad prevents damage of the tie and ballast by reducing the impact and high frequency vibration, which occurs when a vehicle load transfers to a tie. But elasticity of the railpad can decrease under vehicle load and over usable period. If that happens, railpad will become stiffer. Increase in stiffness of the railpad also translates into a rise in track maintenance cost because it accelerates the damage of the track. In this study, accelerated heat ageing test was performed to predict an expectable lifetime of the railpad. As a result, it was predicted to be about sixteen years at $25^{\circ}C$ that life time of railpad using NR rubber from Arrhenius relationship. Also, it was predicted to be about thirty-two days at $100^{\circ}C$. At this time, a standard rate of thickness change is approximately within 12%.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.113-122
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• 2010

고체추진기관의 연소 환경에서 복잡한 형상을 갖는 내열 복합재료의 온도, 밀도분포 및 삭마두께를 예측할 수 있는 방법을 개발하였다. 복합재료의 내부 열반응은 Arrhenius 모델을 이용하였으며, 표면 삭마반응은 Zvyagin 이론을 사용하였다. 표면 삭마에 의한 경계조건 및 격자 이동은 상용해석 코드에서 활용되는 Rezoning-remeshing 기법을 사용하였다. 형상이 복잡한 부품으로 이루어진 2차원 축대칭 노즐 조립체에 적용된 방법은 향후 3차원 FEM 열구조 해석에 활용을 목표로 발전될 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.378-381
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• 2001

The electron drift mobility of poly(4,4'-cyclohexylidenediphenyl carbonate)(PC-Z) doped with 3,5-dimethy-3,5-di-t-butylstilbenequinone(MBSQ), 3,5,3,5-tetra-t-butyl stilbenequinone(TMSQ) and 3,5,3,5-tetra-methyl stilbenequinone(TMSQ) was measured by the time-of-flight technique. The electric field and temperature dependences of the electron drift mobility were discussed with Poole-Frenkel, Arrhenius formulations and non-Arrhenius type of temperature dependence. It was assumed that the hopping sites were Gaussian distribution. Mobility and activation energy of MBSQ were increased with increasing dopant. However, mobilities and activation energy of TBSQ and TMSQ were increased and decreased, respectively.

• Journal of Pharmaceutical Investigation
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• 제18권4호
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• pp.203-208
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• 1988

The stability and solubility of piroxicam in propylene glycol (PG), polyethylene glycol (PEC), and PG-water cosolvents have been studied by using high performance liquid chromatography. The degradation rate followed an apparent first-order kinetic and the reaction rate constants at 70, 80, and $90^{circ}C$ were determined. From these rate constants, the activation energy and the rate constant of piroxicam at $25^{circ}C$ in pure PG calculated by Arrhenius equation were 23.34 kcal/mole and $7.0\;{\times}\;10^{-4}\;day^{-1}$, respectively. Both of PG and PEG increased the solubility of the drug, but PEG was more effective.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제11권3호
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• pp.7-20
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• 2007

We examined the steady state solution for a strongly exothermic mixtures in some class A geometries subjected to different boundary conditions under Arrhenius, Bimolecular and Sensitised reactions. The solution of the governing nonlinear reaction diffusion equation was obtained using the variational method formulation executed in Mathematica package. The paper elucidates the influence of geometry, boundary conditions and types of reaction on the thermal ignition of the reactive mixture. Apart from validating known results in literature, the solution gave further insight into the influence of material properties and conditions on the occurrence of thermal ignition.

• Advances in nano research
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• 제10권5호
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• pp.437-448
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• 2021

In this article, an analytically and numerically 3D nanoliquid flow by a porous rotatable disk is presented in the presence of gyrotactic microorganisms. The mathematical model in the form of partial differential system is transmuted into dimensionless form by utilizing the appropriate transformation. The homotopy analysis approach is applied to attain the analytic solution of the problem. The effect of promising parameters on velocity distribution, temperature profile, nanoparticles volume fraction and motile microorganism distribution field are evaluated through graphs and in tabular form. The existence of Brownian motion and thermophoresis impacts are more proficient for heat transfer enhancement. Further the unique features like heat absorption/generation and energy activation are also examined for the present flow problem. The obtained results are compared with the earliear investigation to check the accuracy of present model.