• Title/Summary/Keyword: Arrhenius

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Application of the Arrhenius Equation in Geotechnical Engineering

  • Yoon, Hyung-Koo
    • The Journal of Engineering Geology
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    • v.24 no.4
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    • pp.575-581
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    • 2014
  • The reliable measurement of geotechnical properties in cold regions should account for their fluctuations with temperature. The objective of this paper is to introduce a chemical model based on the Arrhenius equation that can predict the properties of materials as their temperature changes. The model can monitor phases and reaction rates as they change with temperature. It has been already applied in the fields of geology, construction, chemistry, materials engineering, and food science. The application of the Arrhenius equation requires a reliable estimate of the activation energy. Therefore, this study also demonstrates several methods for evaluating activation energy in different contexts through summaries and reviews of previous research related to the Arrhenius equation. This paper may be of wide use in obtaining temperature-dependent parameters in geotechnical engineering.

A study on the self-life estimation of the propellant KM10 by using high temperature acceleration aging tests (고온가속노화시험을 이용한 추진제 KM10의 저장 수명 추정)

  • Cho, Ki-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.5
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    • pp.1735-1740
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    • 2010
  • The propellant KM10, a single propellant manufactured nitrocellulose, is known to cause natural degradation phenomena at long term storage. The self-life was estimated using generally used high temperature acceleration aging tests to analyze the content of stabilizer and using the Arrhenius equation & Berthelot equation to calculate reaction rate constants. According to the result of this study, self-life of propellant KM10 using the Arrhenius equation & Berthelot equation appear significantly different as 43.73, 16.53years and when compared with the paper of E. R. Bixon, self-life of propellant KM10 predicted using the Arrhenius equation was reasonably determined.

Conditional Confidence Intervals for Accelerated Life Testing in Modified Arrhenius Model (수정 아레니우스 모형에서 가족수명시험에 대한 조건부 신뢰구간)

  • 박병구
    • Journal of Korean Society for Quality Management
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    • v.25 no.3
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    • pp.1-10
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    • 1997
  • In the context of accelerated life tests, procedures are given for estimating the parameters in the modified Arrhenius model and for estimating mean life at a given future stress level. The conditional confidence intervals are obtained by conditioning on ancillary statistics and pivotal quantity. Using the data of Tobias and Trindada(1986), we illustrate conditional confidence interval for parameters under use condition in the modified Arrhenius model.

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Life Expectancy Estimation of the Propellants KM10 using High Temperature Acceleration Aging Tests and Stockpile Analysis Test (고온가속노화시험법과 저장분석시험법을 이용한 추진제 KM10의 기대수명 평가)

  • Cho, Ki-Hong;Kim, Eui Yong
    • Korean Chemical Engineering Research
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    • v.48 no.6
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    • pp.695-699
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    • 2010
  • The propellant KM10, a single propellant manufactured from nitrocellulose, was known to cause natural degradation phenomena at long term storage. In this study, the self-life was estimated using high temperature acceleration aging tests and stockpile analysis test. For the life expectancy estimation, Arrhenius equation and Berthelot equation were used in the high temperature acceleration tests, and the first order regression was used in the Stockpile analysis test. The self-life of propellant KM10 using the Arrhenius equation and Berthelot equation showed significantly different results as 43.73, 16.53 years in the high temperature acceleration test, and it showed 42.94 years in the Stockpile analysis test. The value of self-life predicted by Arrhenius equation was reasonable when compared with the result of E. R. Bixon.

A Comparative Study on Arrhenius-Type Constitutive Models with Regression Methods

  • Lee, Kyunghoon;Murugesan, Mohanraj;Lee, Seung-Min;Kang, Beom-Soo
    • Transactions of Materials Processing
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    • v.26 no.1
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    • pp.18-27
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    • 2017
  • A comparative study was performed on strain-compensated Arrhenius-type constitutive models established with two regression methods: polynomial regression and regression Kriging. For measurements at high temperatures, experimental data of 70Cr3Mo steel were adopted from previous research. An Arrhenius-type constitutive model necessitates strain compensation for material constants to account for strain effect. To associate the material constants with strain, we first evaluated them at a set of discrete strains, then capitalized on surrogate modeling to represent the material constants as a function of strain. As a result, disparate flow stress models were formed via the two different regression methods. The constructed constitutive models were examined systematically against measured flow stresses by validation methods. The predicted material constants were found to be quite accurate compared to the actual material constants. However, notable mismatches between measured and predicted flow stresses were revealed by the proposed validation techniques, which carry out validation with not the entire, but a single tensile test case.

Studies on the Drying Methods of Sea Foods 2. Fixed-Bed Drying of Cuttlefish (수산식품의 건조방법에 관한 연구 2. 갑오징어의 고정층건조)

  • HUR Jong-Wha
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.3
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    • pp.207-210
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    • 1982
  • For the removal of initial water content in cuttlefish, the effects of fixed-bed drying condition on the drying rate were investigated, with following results. 1. The drying rate of cuttlefish dried at fixed-bed condition was also faster than that at natural convection type or hot air dryer.2. By controlling air temperature and its direction to cut-and-peeled sample the drying time can be reduced to 2 hrs. 3. Shirai's equation and Arrhenius' law were applicable to fixed-bed dried cuttlefish. Drying rate constant (k) by Shirai's equation, and Arrhenius' plot were as shown in Table 3, 4 and Fig.3, respectively.

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Arrhenius Kinetic Constants Analysis of BKNO3 under Accelerated Aging (가속노화에 따른 BKNO3의 아레니우스 동역학 상수 분석)

  • Jang, Seung-gyo;Kim, Jun-hyung;Ryu, Byung-tae;Hwang, Jung-min
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.4
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    • pp.34-39
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    • 2016
  • Arrhenius kinetic constants, the activation energy and the pre-exponential factor, of energetic material $BKNO_3$ are estimated using Differential Scanning Calorimetry (DSC). Different from the conventional way, the activation energy was estimated more precisely through DSC aging trial, and the consumed fraction by heat was calculated by comparing the integration of heat flow. We suggested the condition of accelerated aging test for the energetic material $BKNO_3$ and reconsidered the meaning of the thermal accelerated aging.

Study of Kinetics for Removal H2S by Natural Manganese ore Sorbent (황화수소 제거를 위한 천연망간광석 탈황제의 반응 속도 연구)

  • Yoon, Yeo Il;Kim, Myung Wook;Kim, Sung Hyun
    • Clean Technology
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    • v.7 no.3
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    • pp.187-194
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    • 2001
  • The desulfurization process which belongs to the gas refining part is the unit process that eliminates $H_2S$ and COS in the coal gas formed by the coal gasification part in the integrated gasification combined cycle(IGCC). In this study, natural manganese ores were selected as the raw material of the desulfurization sorbent due to economical efficiency. Initial rates for the reactions between $H_2S$ and desulfurization sorbent using natural manganese ores were determined in a temperature range of $400{\sim}800^{\circ}C$ using a thermobalance reactor. All reactions were first order with respect to $H_2S$ and were in accord with the Arrhenius equations. When sulfidation reaction was controlled by diffusion, the temperature dependence of the effective diffusivity was given by the Arrhenius equation. Activation energies and frequency factors were obtained from the product layer diffusion coefficient of various sorbents by plotting as Arrhenius equation form.

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Growth of Clostridium thermobutyricum: a Cellulolytic Thermophile

  • Kuk, Seung-Uk;Hong, Seung-Suh
    • Journal of Microbiology and Biotechnology
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    • v.2 no.4
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    • pp.293-296
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    • 1992
  • Increased concentrations of yeast extract led to increased growth yields and faster growth rates of the newly isolated Clostridium thermobutyricum. This species produced butyrate as its main fermentation product from glucose as well as from yeast extract. In the presence of peptone or tyrptone and during growth on agar, up to 70% of the cells sporulated. Growth yields were 30 and 55 g per mole glucose in the presence of 0.05 and 2.0% yeast extract, respectively. The Arrhenius graph was biphasic, exhibiting an intermediary plateau around $38^{\circ}C$ with a concomitant change in the Arrhenius energy. The optimum temperature was $55^{\circ}C$. An unusually sharp decline in the growth rate occurred above $59^{\circ}C$ .

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Compilation of Respiration Model Parameters for Designing Modified Atmosphere Package of Fresh Produce

  • An, Duck Soon;Lee, Dong Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.21 no.1
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    • pp.1-10
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    • 2015
  • Enzyme kinetics-based respiration model can be effectively used for estimating respiration rate in $O_2$ consumption and $CO_2$ production of fresh produce as a function of $O_2$ and $CO_2$ concentrations. Arrhenius equation can be applied to describe the temperature dependence of the respiration rate. Parameters of enzyme kinetics-based respiration model and activation energy of Arrhenius equation were compiled from analysis of literature data and closed system experiment. They enable to estimate the respiration rate for any modified atmosphere conditions at temperature of interest and thus can be used for design of modified atmosphere packaging of fresh produce.

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