• Journal of Ocean Engineering and Technology
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• v.6 no.1
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• pp.105-112
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• 1992

The main purpose of this study is to derive a law of fatigue crack growth rate in the region of elastic or elasto-plastic fracture mechanics at elevated temperatures through the application of dimensional analysis. An equation of elasto-plastic fatigue crack growth rate at elevated temperatures appeared a new Arrhenius type equation containing J-integral range and absolute temperature. The elastic or elasto-plastic crack growth rate equation shows a fairly good agreement with the experimental results for Cr-Mo-V rotor steel and Hastelloy-X alloy in the comparatively wide temperature ranges.

• 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.

• Journal of Powder Materials
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• v.20 no.1
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• pp.48-52
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• 2013

A study of oxidation kinetic of Fe-36Ni alloy has been investigated using thermogravimetric apparatus (TGA) in an attempt to define the basic mechanism over a range of temperature of 400 to $1000^{\circ}C$ and finally to fabricate its powder. The oxidation rate was increased with increasing temperature and oxidation behavior of the alloy followed a parabolic rate law at elevated temperature. Temperature dependence of the reaction rate was determined with Arrhenius-type equation and activation energy was calculated to be 106.49 kJ/mol. Based on the kinetic data and micro-structure examination, oxidation mechanism was revealed that iron ions and electrons might migrate outward along grain boundaries and oxygen anion diffused inward through a spinel structure, $(Ni,Fe)_3O_4$.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1552-1560
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• 1990

A general form of the mathematical function in the fatigue crack growth rate law for CT specimens was determined by means of the dimensional analysis at elevated temperatures. The experimental results can be rigorously described by the combination of rate theory and fracture mechanics. The rate theory approach extends the scope of fracture mechanics through the consideration of the temperature. The fatigue crack growth rates are represented by the Arrhenius type equation. This equation explains fairly well the experimental data for Cr-Mo-V rotor steel and A517-F steel in the comparatively wide temperature regions as affected with the temperature and the stress intensity factor range interaction.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1997-2002
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• 2007

The reformer is one of the most important chemical processes for the production of high purity hydrogen from fossil fuel. This study compares zero-dimensional model with CFD models for reaction analysis of methane-steam reformer. The zero-dimensional model is an empirical equation, however CFD model uses reactions of Arrhenius type. Because the reaction coefficients of the steam-methane catalytic reforming have not been reported before in the form of Arrhenius type, the present study aims to find the appropriate reaction coefficients. The used CFD code is Fluent 6.2 version. Several models are compared for the case of various operating temperature, mass of catalyst and steam to methane ratio.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.558-564
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• 1993

The drying characteristics of fluidized bed drying with different drying conditions using naked barley were carried out. This fluidized drying mechanism of naked barley was consisted of consecutive two falling rate parts, first falling rate period and second falling rate period without showing constant rate period. The drying rate constant was increased with decreasing charged amount and relative humidity and increasing air temperature and air velocity. Since the drying rate constant expressed by Arrhenius type equation in the falling rate period showed good linearity, the falling rate period was considered as the controlling step. The activation energy of first falling step was 1,900 cal/gmol, while for second falling step the values showed 2,500 cal/gmol.

• Food Science and Preservation
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• v.24 no.4
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• pp.505-509
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• 2017

Water vapor adsorption kinetics of vacuum-dried jujube powder were investigated in temperature and relative humidity ranges of 10 to $40^{\circ}C$ and 32 to 75%, respectively. Water vapor was initially adsorbed rapidly and then reached equilibrium condition slowly. Reaction rate constant for water vapor adsorption of vacuum-dried jujube powder increased with an increase in temperature. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Good straight lines were obtained with plotting of $1/(m-m_0)$ vs. 1/t. It was found that water vapor adsorption kinetics of vacuum-dried jujube powder was accurately described by a simple empirical model, and temperature dependency of the reaction rate constant followed the Arrhenius-type equation. The activation energy ranged from 50.90 to 56.00 kJ/mol depending on relative humidity. Arrhenius kinetic parameters ($E_a$ and $k_0$) for water vapor adsorption by vacuum-dried jujube powder showed an effect between the parameters with the isokinetic temperature of 302.51 K. The information on water vapor adsorption kinetics of vacuum-dried jujube powder can be used to establish the optimum condition for storage and processing of jujube.

• Journal of the Korean institute of surface engineering
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• v.44 no.4
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• pp.131-136
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• 2011

A kinetic study has been made for the growth of nanocrystalline diamond (NCD) particles to a continuous thin film on silicon substrate in a microwave plasma chemical vapor deposition reactor. Parameters of deposition have been microwave power of 1.2 kW, the chamber pressure of 110 Torr, and the Ar/$CH_4$ ratio of 200/2 sccm. The deposition has been carried out at temperatures in the range of $400\sim700^{\circ}C$ for the times of 0.5~16 h. It has been revealed that a continuous diamond film evolves from the growth and coalescence of diamond crystallites (or particles), which have been heterogeneously nucleated at the previously scratched sites. The diamond particles grow following an $h^2$ = k't relationship, where h is the height of particles, k' is the particle growth rate constant, and t is the deposition time. The k' values at the different deposition temperatures satisfy an Arrhenius equation with the apparent activation energy of 4.37 kcal/mol or 0.19 eV/ atom. The rate limiting step should be the diffusion of carbon species over the Si substrate surface. The growth of diamond film thickness (H) shows an H = kt relationship with deposition time, t. The film growth rate constant, k, values at the different deposition temperatures show another Arrhenius-type expression with the apparent activation energy of 3.89 kcal/mol or 0.17 eV/atom. In this case, the rate limiting step might be the incorporation reaction of carbon species from the plasma on the film surface.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.286-288
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• 2014

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.711-717
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• 1988

The diffusivity of sodium chloride in Chinese cabbage was evaluated from its absorption data obtained by immersing the cabbage stalk in a salt solution. By using least squares method, the absorption and desorption diffusivity of NaCl in the cabbage stalk have been estimated to be $1.7{\times}10^{-11}$ and $11.6{\times}10^{-11}m^2/s$, respectively. The apparent diffusivity was not strongly dependent on the concentration of brine and the variety of Chinese cabbage. The influence of temperature on the apparent diffusivity could be expressed as the Arrhenius type equation, in which the activation energy was estimated to be 66 KJ/mol.