• Journal of Environmental Science International
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• v.26 no.3
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• pp.363-371
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• 2017

This study evaluates the adsorption properties of Sr ions in an aqueous solution of the synthetic zeolite (Z-Y1) prepared using coal fly ash generated from a thermal power plant. In order to investigate the adsorption characteristics, the effects of various parameters such as the initial concentrations of Sr ion, contact time, and solution pH were investigated in a batch mode. The Langmuir and Redlich-Peterson model fitted the adsorption isotherm data better than the Freundlich model. The maximum adsorption capacity of Sr ions, as determined the Langmuir model, was 181.68 mg/g. It was found that by varying the Sr ion concentration, pH, and temperature, the pseudo-second-order kinetic model describes the adsorption kinetics of the Sr ion better than the pseudo-first-order kinetic model. The calculated thermodynamic parameters of ${\Delta}H^0$ and ${\Delta}G^0$ showed that the adsorption of Sr ions on Z-Y1 was occurred through a spontaneous and an endothermic reaction. We found that the adsorption of Sr ions by Z-Y1 was more affected by pH than by temperature and Sr ion concentration.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.217-221
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• 2013

This study developed predictive models for the kinetic behavior of Staphylococcus aureus on processed cheeses. Mozzarella slice cheese and cheddar slice cheese were inoculated with 0.1 ml of a S. aureus strain mixture (ATCC13565, ATCC14458, ATCC23235, ATCC27664, and NCCP10826). The inoculated samples were then stored at $4^{\circ}C$ (1440 h), $15^{\circ}C$ (288 h), $25^{\circ}C$ (72 h), and $30^{\circ}C$ (48 h), and the growth of all bacteria and of S. aureus were enumerated on tryptic soy agar and mannitol salt agar, respectively. The Baranyi model was fitted to the growth data of S. aureus to calculate growth rate (${\mu}_{max}$; ${\log}CFU{\cdot}g^{-1}{\cdot}h^{-1}$), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The growth parameters were further analyzed using the square root model as a function of temperature. The model performance was validated with observed data, and the root mean square error (RMSE) was calculated. At $4^{\circ}C$, S. aureus cell growth was not observed on either processed cheese, but S. aureus growth on the mozzarella and cheddar cheeses was observed at $15^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$. The ${\mu}_{max}$ values increased, but LPD values decreased as storage temperature increased. In addition, the developed models showed acceptable performance (RMSE = 0.3500-0.5344). This result indicates that the developed kinetic model should be useful in describing the growth pattern of S. aureus in processed cheeses.

• Proceedings of the KTCVS Conference
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• 1993.06a
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• pp.119-119
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• 1993

• Journal of the East Asian Society of Dietary Life
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• v.18 no.3
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• pp.384-390
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• 2008

This study examined the effects of sprouted brown rice (SR), gluten (G), and hydroxypropyl-methyl-cellulose (H) on the suppression of retrogradation in breads made with Korean wheat flour. An amylograph was used to determined the pasting properties of dough samples made with Korean wheat flour and additions of SR, SR+G, SR+H, and SR+G+H, respectively. In addition, a texture analyzer was employed to measure the hardness changes of bread samples left at room temperature for 72 hours. Finally, the type of retrogradation was calculated by the Avrami equation. The results showed that the addition of SR significantly decreased dough viscosity. However, the dough samples containing SR, G, and H all displayed reduced cold paste viscosity and setback, indicating a suppression of staling. The bread samples containing SR added to Korean wheat flour had increased hardness, but the addition of gluten (SR+G) reduced hardness. Upon examining the bread samples stored at room temperature for 24 hours, it was shown that the addition of G and H with SR (SR+G+H) suppressed retrogradation. Finally, the Avrami model data indicated that the type of retrogradation varied according to the addition of SR, G, and H. The breads made with hard wheat flour (HWF), WM, and WM+SR+H had similar Avrami exponents ($1.20{\sim}1.28$), while those for WM+SR, WM+SR+G, and WM+SR+G+H ranged from 2.7 to 3.3. Overall, the combined addition of SR and H was considered effective for preventing retrogradation in bread made with Korean wheat flour.

• Journal of Environmental Science International
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• v.2 no.4
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• pp.271-278
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• 1993

Optimal biodegradation kinetics models to the initial nonylphenol ethoxylates-30 concentration were investigated and had been fitted by the linear regression. Microorganisms capable of degrading nonylphenol ethoxylates-30 were isolated from sewage near Ulsan plant area by enrichment culture technique. Among them, the strain designated as EL-10K had the highest biodegradability and was identified as Pseudomonas from results of taxonomical studies. The optimal conditions for the biodegradation were 1.0 g/ι of nonylphenol ethoxylates-30 and 0.02 g/ι of ammonium nitrate at pH 7.0 and 3$0^{\circ}C$. The highest degradation rate of nonylphenol ethoxylates-30 was about 89% for 30 hours incubation on the optimal condition. Biodegradation data were fit by linear regression to equations for 3 kinetic models. The kinetics of biodegradation of nonylphenol ethoxylates was best described by first order model for 0.1 $\mu\textrm{g}$/ι nonylphenol ethoxylates-30 ; by Monod no growth model and Monod with growth model for 0.5 $\mu\textrm{g}$/mι and 1.0, 5.0 $\mu\textrm{g}$/mι, respectively.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.3
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• pp.179-188
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• 2007

In this work $^{14}C\;and\;^3H$ distribution characteristics of spent resins from nuclear power plants(NPPs), pressurized water reactors(PWRs), was investigated. It was found that the recovery percent of $^{14}C$ by the wet oxidation-acid stripping was $81%{\sim}100%$ for the added activity range of $^{14}C,\;0.72\;Bq{\sim}460\;Bq$, and it was not affected by the kinds of stripping acids, 3N-HCl, $3\;N-HNO_3\;and\;3\;N-H_2SO_4$. And the recovery percent of $^3H$ by distillation using the same apparatus was $81%{\sim}101%$ for the added activity range of $^3H,\;0.60\;Bq{\sim}435\;Bq$. Among the tested stripping acids, 3\;N-HCl, $3\;N-HNO_3\;and\;3\;N-H_2SO_4$, only the trapped $^3H$ solution by distillation in $3\;N-H_2SO_4$ was compatible with the 3H scintillator, Ultimagold XR. Neither of the $^{14}C\;and\;^3H$ trapping solutions from the spent ion exchange resin samples by the wet oxidation-3 $N-H_2SO_4$ stripping contained gamma nuclides. However, some gamma nuclides, $^{60}Co,\;^{134}Cs,\;^{137}Cs\;and\;^{54}Mn$, were found in the trapped $^3H$ solutions of the spent resins by the wet oxidation-3 N-HCl stripping. It was the same for the $^3H$ trapping solutions of the spent resins by Sample Oxidizer(PACKARD MODEL 307). Meanwhile only two nuclides, $^{134}Cs,\;and\;^{134}Cs$, were found in the $^{14}C$ trapping solutions of the spent resins by Sample Oxidizer(PACKARD MODEL 307). It was found that most of the $^{14}C$ in the spent resins existed as inorganic carbon form, more than about 70% of the total $^{14}C$ content. Among the analyzed 30 spent ion exchange resin samples, the average concentration of $^{14}C$ and $^3C$ for the high radioactive samples, 8 samples, was $19000\;Bq/g{\pm}41000\;Bq/g,\;670\;Bq/g{\pm}460\;Bq/g$ and that for the low radioactive samples, 22 samples, was $4.2\;Bq/g{\pm}4.3\;Bq/g,\;6.0\;Bq/g{\pm}5.3\;Bq/g$, respectively. And the average $^{14}C/^3H$ ratio for the high radioactive samples, was higher, 28, than that of low radioactive samples, 0.70. Some linear relationship trend was found between the activity concentrations of $^{14}C\;and\;^3H$.

• Journal of fish pathology
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• v.24 no.1
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• pp.29-37
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• 2011

Effects of temperature ($13{\pm}1.5^{\circ}C$, $23{\pm}1.5^{\circ}C$) on the pharmacokinetic properties of nalidixic acid (NA) and piromidic acid (PA) were studied after oral administration to cultured black rockfish, Sebastes schlegeli. Serum concentrations of NA and PA were determined using HPLC-UV detector after a single dosage of 60 mg/kg body weight. At $23{\pm}1.5^{\circ}C$, the peak serum concentrations of NA and PA, which attained at 24 h post-dose, were 5.87 and $0.43\;{\mu}g/ml$, respectively. At $13{\pm}1.5^{\circ}C$, the peak serum concentrations of NA and PA, which attained at 10 h post-dose, were 6.22 and $1.57\;{\mu}g/ml$, respectively. Better absorption of PA was noted at $13{\pm}1.5^{\circ}C$ compared to $23{\pm}1.5^{\circ}C$. However, absorption of NA was not affected significantly by temperature. The elimination of NA and PA from serum of black rockfish was considerably faster at $23{\pm}1.5^{\circ}C$ than at $13{\pm}1.5^{\circ}C$. The kinetic profile of absorption, distribution and elimination of NA and PA in serum were analyzed by fitting to a one compartment model, with WinNonlin program. The AUC, $T_{1/2}$, $T_{max}$ and $C_{max}$, respectively, were: $161.25\;{\mu}g{\cdot}h/ml$, 0.15 h, 12.29 h and $8.91\;{\mu}g/ml$ at $23{\pm}1.5^{\circ}C$, and $134.12{\mu}g{\cdot}h/ml$, 0.18 h, 8.79 h and $5.00\;{\mu}g/ml$ at $13{\pm}1.5^{\circ}C$ with NA; $41.57\;{\mu}g{\cdot}h/ml$, 0.58 h, 8.24 h and $0.21\;{\mu}g/ml$ at $23{\pm}1.5^{\circ}C$, and $40.36\;{\mu}g{\cdot}h/ml$, 0.59 h, 5.04 h and $1.20\;{\mu}g/ml$ at $13{\pm}1.5^{\circ}C$ with PA.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.7
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• pp.725-731
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• 2008

This paper focused on the application of finite element model updating technique to evaluate the structural properties of the reinforced concrete specimen using the data collected from shaking table tests. The specimen was subjected to six El Centre (NS, 1942) ground motion histories with different peak ground acceleration (PGA) ranging from 0.06 g to 0.50 g. For model updating, flexural stiffness values of structural members (walls and slabs) were chosen as the updating parameters so that the converged results have direct physical interpretations. Initial values for finite element model were determined from the member dimensions and material properties. Frequency response functions (i.e. transfer functions), natural frequencies and mode shapes were obtained using the acceleration measurement at each floor and given ground acceleration history. The weighting factors were used to account for the relative confidence in different types of Inputs for updating (j.e. transfer function and natural frequencies) The constraints based on upper/lower bound of parameters and sensitivity-based constraints were implemented to the updating procedure in this study using standard bounded variable least-squares(BVLS) method. The veracity of the updated finite element model was investigated by comparing the predicted and measured responses. The results indicated that the updated model replicates the dynamic behavior of the specimens reasonably well. At each stage of shaking, severity of damage that results from cracking of the reinforced concrete member was quantified from the updated parameters (i.e. flexural stiffness values).

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.149-158
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• 1998

Biomass of non-living brown seaweed Sargassun fluitans pretreated with NaOH is capable of taking up more than $10\%$ $(q_{max}$ : 3.85 mmol/g for Al and 1.48 mmol/g for Cu) of its dry weight in the Al and Cu at pH of 4.5. However, the maximum Al and Cu uptakes calculated from Langmuir isotherm were 1.58 mmol/g for Al and 1.35 mmol/g for Cu at pH 3.5. Equilibrium batch sorption study was performed using two-metal system containing Al and Cu. The mathematical model of the two-metal sorption system enabled quantitative estimation of one-metal biosorption inhibition due to the influence of a second metal. NaOH-treated S. fluitans contained 2.19 mmol $(43\;wt.\%)$ carboxyl groups per gram of biomass. A modified form of Langmuir, which assumes binding of Cu as $Cu^{2+}$ and Al as $Al(OH)_2^+,$ was used to model the experimental data. This result agrees with the one of mono-valent sorption for Al in single-metal system. The modified Langmuir model gives the following affinity correlated coefficients: 0.196 for Cu and 6.820 for Ah at pH 4.5, and 2.904 for Cu and 3.131 for Al at pH 3.5. The interference of Al in Cu biosorptive uptake was assessed by `cutting' the three dimensional uptake isotherm surfaces at constant second-metal final concentrations. Equimolar final equilibrium concentrations of Cu and Al of 1 mM at pH 4.5 give Cu and hi uptakes reduced by $82.5\%\;and\;5.4\%,$ respectively. However, these values at pH 3.5 were $55\%\;(Cu)\;and\;31\%$ (Al).

• Journal of fish pathology
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• v.22 no.1
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• pp.91-95
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• 2009

The pharmacokinetic properties of oxytetracycline (OTC) were studied after intramuscular injection to cultured olive flounder, Paralichthys olivaceus. Plasma concentrations of OTC were determined after dosage of 12.5, 25 and 50 ㎎/㎏ body weight in olive flounder (average 600 g, $23{\pm}1{^{\circ}C}$). Plasma samples were taken at 3, 5, 10, 15, 24, 32, 48, 72, 120, 168, 240 and 360 h post-dose. With 25 and 50 ㎎/㎏, the peak plasma concentrations of OTC, which attained at 5 h post-dose, were 0.99 and 1.49 $\mu{g}/m\ell$, respectively. However, the peak plasma concentration of 12.5 ㎎/㎏ was 0.35 $\mu{g}/m\ell$ after 10 h post-dose. Plasma concentrations of OTC were not measurable at 360 h post-dose in all doses. The kinetic profile of absorption, distribution and elimination of OTC in plasma were analyzed fitting to a 1-compartment model by Win-Nonlin program. The following parameters were calculated for 12.5, 25 and 50 ㎎/㎏ body weight, respectively: AUC (the area under the concentration-time curve)?D���D24.98, 44.67 and 50.45 $\mu{g}$ $h/m\ell$ $T_{1/2}$ (half-life) ?D���D0.42, 0.59 and 0.41 h; $T_{max}$ (time for maximum concentration)?D���D8.46, 6.34 and 2.66 h; $C_{max}$ (maximum concentration)?D���D0.30, 0.63 and 1.13 $\mu{g}/m\ell$.