• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.173-183
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• 2019

Objective: The aim of this study was to investigate the correlation coefficients between anthropometric parameters of the foot and kinetic variables during running. Method: This study was conducted on 21 healthy young adults (age: $24.8{\pm}2.1yes$, height: $177.2{\pm}5.8cm$, body mass: $73.3{\pm}7.3kg$, foot length: $256.5{\pm}12.3mm$) with normal foot type and heel strike running. To measure the anthropometric parameters, radiographs were taken on the frontal and sagittal planes, and determined the length and width of each segment and the navicular height. Barefoot running was performed at a preferred velocity ($3.0{\pm}0.2m/s$) and a fixed velocity (4.0 m/s) on treadmill (Bertec, USA) in order to measure the kinetic variables. The vertical impact peak force, the vertical active peak force, the braking peak force, the propulsion peak force, the vertical force at mid-stance (vertical ground reaction when the foot is fully landed in mid-stance or at the point where the weight was uniformly distributed on the foot) and the impact loading rate were calculated. Pearson's correlation coefficient was used to investigate the relationship between anthropometric variables and kinetical variables. The significance level was set to ${\alpha}=.05$. Results: At the preferred velocity running, the runner with longer forefoot had lower active force (r=-.448, p=.041) than the runner with short forefoot. At the fixed velocity, as the navicular height increases, the vertical force at full landing moment increases (r= .671, p= .001) and as the rearfoot length increases, the impact loading rate decreases (r=- .469, p= .032). Conclusion: There was a statistically significant difference in the length of fore-foot and rearfoot, and navicular height. Therefore it was conclude that anthropometric properties need to be considered in the foot study. It was expected that the relationship between anthropometric parameters and kinetical variables of foot during running can be used as scientific criteria and data in various fields including performance, injury and equipment development.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.11a
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• pp.137-144
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• 1996

The kinetic coefficients far decomposition of the cured phenol resin (SC-1008) using a modified Arrhenius relationship have been determined from thermogavimetric analyses (TGA). The kinetic parameters were determined by multiple heating rate technique developed by Freideman and Henderson. Weight loss (decomposition) and weight loss rate (decomposition rate)were measured and recorded for three heating rates; $5^{\circ}C$/min ,$10^{\circ}C$/min, and $20^{\circ}C$/min. Relatively good agreement was obtained between measured and calculated decomposition as a function of temperature. By separating the reaction, the reaction order and pre exponential factor become empirical parameters which provide a "best fit" of the data. However, this method yields an extremely accurate reproduction of the thermograms over a wide range of heating rates. This is the desired result for kinetic parameters used in thermal models.al models.

• Food Science of Animal Resources
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• v.36 no.2
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• pp.262-266
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• 2016

This study evaluated the growth kinetics of Salmonella spp. in processed meat products formulated with low sodium nitrite (NaNO₂). A 5-strain mixture of Salmonella spp. was inoculated on 25-g samples of sausages formulated with sodium chloride (NaCl) (1.0%, 1.25%, and 1.5%) and NaNO₂ (0 and 10 ppm) followed by aerobic or vacuum storage at 10℃ and 15℃ for up to 816 h or 408 h, respectively. The bacterial cell counts were enumerated on xylose lysine deoxycholate agar, and the modified Gompertz model was fitted to the Salmonella cell counts to calculate the kinetic parameters as a function of NaCl concentration on the growth rate (GR; Log CFU/g/h) and lag phase duration (LPD; h). A linear equation was then fitted to the parameters to evaluate the effect of NaCl concentration on the kinetic parameters. The GR values of Salmonella on sausages were higher (p<0.05) with 10 ppm NaNO₂ concentration than with 0 ppm NaNO₂. The GR values of Salmonella decreased (p<0.05) as NaCl concentration increased, especially at 10℃. This result indicates that 10 ppm NaNO₂ may increase Salmonella growth at low NaCl concentrations, and that NaCl plays an important role in inhibiting Salmonella growth in sausages with low NaNO₂.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1073-1078
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• 2009

A kinetic model for the oxidation of a $UO_2$ pellet to $U_3O_8$ powder has been suggested by considering the mass transfer and the diffusion of oxygen molecules. The kinetic parameters were estimated by a fitting of the experimental data. The activation energies for the chemical reaction and the product layer diffusion were calculated from the kinetic model. The oxidation conversion of a $UO_2$ pellet was simulated at various operating conditions. The suggested model explains the oxidation behavior of $UO_2$ well.

• Journal of Ginseng Research
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• v.39 no.4
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• pp.304-313
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• 2015

Background: Ginsenoside Rg3 is a promising anticancer agent. It is usually produced by heat treatment of ginseng, in which ginsenoside Rb1 is the major ginsenoside. A kinetic study was conducted to optimize ginsenoside Rg3 production by the heat treatment of ginsenoside Rb1. Methods: Ginsenoside Rb1 was heated using an isothermal machine at $80^{\circ}C$ and $100^{\circ}C$ and analyzed using HPLC. The kinetic parameters were calculated from the experimental results. The activation energy was estimated and used to simulate the process. The optimized parameters of ginsenoside Rg3 production are suggested based on the simulation. Results: The rate constants were $0.013h^{-1}$ and $0.073h^{-1}$ for the degradation of ginsenosides Rb1 and Rg3 at $80^{\circ}C$, respectively. The corresponding rate constants at $100^{\circ}C$ were $0.045h^{-1}$ and $0.155h^{-1}$. The estimated activation energies of degradation of ginsenosides Rb1 and Rg3 were 69.2 kJ/mol and 40.9 kJ/mol, respectively. The rate constants at different temperatures were evaluated using the estimated activation energies, and the kinetic profiles of ginsenosides Rb1 and Rg3 at each temperature were simulated based on the proposed kinetic model of consecutive reaction. The optimum strategies for producing ginsenoside Rg3 from ginsenoside Rb1 are suggested based on the simulation. With increased temperature, a high concentration of ginsenoside Rg3 is formed rapidly. However, the concentration decreases quickly after the reaching the maximal concentration value. Conclusion: The optimum temperature for producing ginsenoside Rg3 should be the highest temperature technically feasible below $180^{\circ}C$, in consideration of the cooling time. The optimum reaction time for heat treatment is 30 min.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.914-920
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• 2018

The intrinsic kinetic parameters of steam-methane reforming reactions over commercial nickel-based catalyst were determined. The reaction rate equations were derived from the reaction mechanism-based Langmuir-Hinshelwood chemisorption theory. As the experimental variables for the kinetic study, the reaction temperature ranged from 630 to $750^{\circ}C$ and the steam-to-carbon ratio also varied from 2.7 to 3.5. Based on the experimental data, the efficient optimization algorithm was used to determine the intrinsic kinetic parameters due to the high-dimensional objective function. It is confirmed that the parameter estimation results showed good agreement with the experimental values. Thus, this proposed mathematical reaction model can be used as the basic information to design a catalytic reactor and to optimize operating conditions.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.220-221
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• 1987

• Food Science of Animal Resources
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• v.33 no.2
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• pp.155-161
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• 2013

This study developed predictive models to evaluate the kinetic behaviors of Bacillus cereus and Staphylococcus aureus in milk during storage at various temperatures. B. cereus and S. aureus (3 Log CFU/mL) were inoculated into milk and stored at $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, as well as $5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$, respectively, while bacterial populations were enumerated. The growth data were fitted to the modified Gompertz model to estimate kinetic parameters, including the maximum specific growth rate (${\mu}_{max}$; Log CFU/[$mL{\cdot}h$]), lag phase duration (LPD; h), lower asymptote ($N_0$; Log CFU/mL), and upper asymptote ($N_{max}$; Log CFU/mL). To describe the kinetic behavior of B. cereus and S. aureus, the parameters were fitted to the square root model as a function of storage temperature. Finally, the developed models were validated with the observed data, and Bias (B) and Accuracy (A) factors were calculated. Cell counts of both bacteria increased with storage time. Primary modeling yielded the following parameters; ${\mu}_{max}$: 0.14-0.75 and 0.06-0.51 Log CFU/mL/h; LPD: 1.78-14.03 and 0.00-1.44 h, $N_0$: 3.10-3.37 and 2.09-3.07 Log CFU/mL, and $N_{max}$: 7.59-8.87 and 8.60-9.32 Log CFU/mL for B. cereus and S. aureus, respectively. Secondary modeling yielded a determination of coefficient ($R^2$) of 0.926.0.996. B factors were 1.20 and 0.94, and A factors were 1.16 and 1.08 for B. cereus and S. aureus, respectively. Thus, the mathematical models developed here should be useful in describing the kinetic behaviors of B. cereus and S. aureus in milk during storage.

• KSBB Journal
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• v.21 no.1 s.96
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• pp.49-53
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• 2006

The aim of this research is to estimate the values of biological kinetic parameters of pharmaceutical wastewater for understanding biochemical properties. Maximum specific growth rate (${\mu}m$), yield coefficient (Y), and half-velocity coefficient (KS) were determined using oxygen uptake rate (OUR), and the results were 10.49/day (0.437/hr), 0.655, and 38.89 mg/L, respectively. Measured ${\mu}max$ by nonlinear regression of Monod equation was 10.63/day (or 0.443/hr), and this value was similar with above result. These parameters may be used to increase efficiency of pharmaceutical wastewater treatment and to determine amount of oxygen needed to removal BOD and dissolved oxygen in activated sludge process.

• Carbon letters
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• v.12 no.3
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• pp.143-151
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• 2011

Bagasse fly ash (BFA) is one of the important wastes generated in the sugar industry; it has been studied as a prospective low-cost adsorbent in the removal of congo red (CR) from aqueous solutions. Chemical treatment with $H_2O_2$ was applied in order to modify the adsorbability of the raw BFA. Batch studies were performed to evaluate the influence of various experimental parameters such as dye solution pH, contact time, adsorbent dose, and temperature. Both the adsorbents were characterized by Fourier-transform infrared spectrometer, energy-dispersive X-ray spectrophotometer and nitrogen adsorption at 77 K. Equilibrium isotherms for the adsorption of CR were analyzed by Langmuir, Freundlich and Temkin models using non-linear regression technique. Intraparticle diffusion seems to control the CR removal process. The obtained experimental data can be well described by Langmuir and also followed second order kinetic models. The calculated thermodynamic parameters indicate the feasibility of the adsorption process for the studied adsorbents. The results indicate that BFA can be efficiently used for the treatment of waste water containing dyes.