• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.57-62
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• 2007

Microbiological, pH, and sensory evaluations on pork tender-loins treated with potassium sorbate (PS) during storage at $4^{\circ}C$ were assessed. Treatments of 0.5-2.0% PS for 10 min effectively (P < 0.05) inhibited the growth of aerobic plate counts (APC) and gram-negative bacterial counts (GNC) compared to those of controls for 9 days at $4^{\circ}C$, respectively. Results of this investigation demonstrate that antimicrobial activity on APC and GNC in all treatments enhanced by increasing concentrations of PS during storage at $4^{\circ}C$. pH values of pork tender-loins treated with PS gradually increased by storage of 6 days at $4^{\circ}C$. Sensory data showed that 0.5-1.0% PS treatments were quite close in odor and appearance compared to fresh controls. Results indicated that pork tender-loins treated with 1.0% PS for 10 min could extend shelf-life to 9 days during refrigerated storage at $4^{\circ}C$ without adversely affecting sensory quality.

• KSBB Journal
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• v.22 no.4
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• pp.244-248
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• 2007

The treatment of a model wastewater containing high concentration, 10 $g/{\ell}$, of phenol in an integrated wet oxidation-aerobic biological treatment was investigated. Partial wet oxidation under mild operating conditions was capable of converting the original phenol to biodegradable organic acids such as maleic acid, formic acid and acetic acid, the solution of which was subjected to the subsequent aerobic biological treatment. The wet oxidation was carried out at 150$^{\circ}C$ and 200$^{\circ}C$ and the initial pH of 1 to 12. The high temperature of 200$^{\circ}C$ and the acidic initial condition in the wet oxidation led to effluents of which biodegradability was higher in the subsequent biological oxidation process, as assessed by chemical oxygen demand (COD) removal. Homogeneous catalyst of $CuSO_4$ was also used for increasing the oxidation rate in the wet oxidation at 150$^{\circ}C$ and initial pH of 3.0. However, the pretreatment with the catalytic wet oxidation resulted in effluents which were less biodegradable in the aerobic biological process compared to those out of the non-catalytic wet oxidation at the same operating conditions.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.4
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• pp.481-487
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• 2014

This study examined microbiological contamination of street foods(kimbab, fish cake, Korean sausage) by microbiological analysis. A collection of 360 samples of street foods was obtained seasonally in four major cities(Seoul, Daejeon, Busan, Gwangju) in Korea. Aerobic mesophilic counts ranged between 1.0 and 9.9 log CFU/g, with the highest count recorded from Kimbab. Counts of psychrotrophic microorganisms were as high as those of mesophilic microorganisms. Total coliform populations between <1.0 and 7.5 log CFU/g were found in 53.6% of samples. Escherichia coli 4.4%, Staphylococcus aureus 7.8% and Clostridium perfringens 3.3%. Salmonella spp. and Listeria monocytogenes were not detected in any of the samples. Kimbab purchased in spring and summer showed higher S. aureus and Cl. perfringens contamination rates. Microbial contamination levels determined in the present study may be used as the primary data to execute microbial risk assessment of street foods.

• Journal of the Korean GEO-environmental Society
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• v.9 no.4
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• pp.77-84
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• 2008

Soil purification theory is the method using the soil micro-organism like aerobic and anaerobic for treatment of wastewater. The soil has many kinds of micro-organism and it multiply as change of the environment. Unlikely other methods, the soil purification theory is adaptable to inflow water change; moreover, it can process the T-N, T-P without any special method and management. The top is covered with the improved soil which can remove the bad smell and is used for resting place according to planting the lawn. This study is focused on analysis of the treatment processing of wastewater comparing inflow with outflow water. As a results, removal rate of the processing the BOD, COD and SS is almost 90~100% and it is 60~80% in T-N, T-P.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.281-285
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• 2014

$Pd/TiO_2$ particles were prepared by wet impregnation for aerobic benzyl alcohol oxidation. Catalysts were prepared by the impregnation of 10 wt% palladium on $TiO_2$ after calcination at various temperatures. The surface areas of the catalysts were changed with calcination temperature. The catalyst calcined at $300^{\circ}C$ possessed the highest surface areas. Catalytic activity of the prepared samples was examined for aerobic benzyl alcohol oxidation. Among the samples, $Pd/TiO_2$ calcined at $300^{\circ}C$ showed the highest catalytic activity. Moreover, the catalysts with various Pd concentrations from 5 wt% to 15 wt% were prepared to investigate an optimum catalyst. 10 wt% $Pd/TiO_2$ was the most active in this reaction due to its higher surface areas and metal dispersion.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.819-823
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• 2011

The present study evaluated the seasonal changes of the soil microbial population by selected media in an organic farming system (OFS) with rye rotation cropping management compared to those in a conventional farming system (CFS) with chemical fertilizers, pesticide and herbicide from May 2009 to October 2010 in an upland field. With the exception of fungi, populations of aerobic bacteria, Gram-negative bacteria, and Bacillus spp. were higher in the OFS soil during soybean-growing stages. In addition, populations of aerobic bacteria, Gram-negative bacteria, and Bacillus spp. in the OFS soil were nearly two times more than those in the CFS soil on reproductive growth stages. Our findings suggested that Bacillus spp. should be considered as responsible factor for microbial population differentiation observed between the OFS and the CFS in upland fields.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.814-818
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• 2011

The seasonal changes were evaluated in the soil microbial populations by selected media in an organic farming system (OFS) with no-till management compared to those in a conventional farming system (CFS) with tillage and synthetic amendments in a flooded paddy from 2009 to 2010. The populations of aerobic bacteria and fungi in the OFS were significantly higher than those in the CFS at the harvesting stages, whereas those of Gram-negative bacteria was significantly higher in the OFS than in the CFS before the submerging stages. In addition, populations of aerobic bacteria, Gram-negative bacteria, and fungi tended to rapidly decreased after the submerging stages may be due to insufficient oxygen. Gram-negative bacteria should be considered as potential factor responsible for the microbial population differentiation observed between the OFS and the CFS in flooded paddy fields.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.113-118
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• 2006

Cost estimation of an intermittent aerobic digestion technology was carried out in this study. Aeration ratio is one of the most important design factors and it affects installation and power consumption cost. For the purpose, digestion efficiency was fixed at 35% of SS reduction and the reactor type was assumed a 2-chamber sequencing batch reactor (SBR). Installation cost and power consumption cost were evaluated and converted in terms of present value that could reflect the rate of discount and the rate of economic growth. The lower aeration ratio needs higher installation cost but lower power consumption cost. From the point of only installation cost, conventional aerobic digestion is cheaper than intermittent aerobic digestion. But intermittent aerobic digestion is better economical for more than 10 years of estimated service life. The optimal aeration ratio was dependent on the service life and it was lower as the estimated service life increased. For the 45 years as the service life, the optimal aeration ratio was estimated 0.3 and the total cost was 64% of the conventional aerobic digestion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.433-437
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• 2006

Recently, mathematical modeling for the activated sludge process is important to design and control of wastewater treatment plant. Nevertheless, there is a lack of information regarding the pathway of substrate utilization between external and internal substrates in biological nutrient removal (BNR). In this research, a new activated sludge model (step growth model) is proposed and compare with ASM No.3. This model structure is consist of five processes; aerobic storage, growth on external substrate and stored intercellular storage compounds (ISCs), endogenous respiration and aerobic respiration of ISCs. The predicted results by the step growth model were more good accordance with the results of oxygen utilization rate (OUR) and TCOD experiment than that of the ASM No.3.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.277-283
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• 2016

To improve the microbiological safety of wild vegetables after harvest, Aster scaber and Cirsium setidens Nakai were treated with combinations of 50 ppm aqueous chlorine dioxide ($ClO_2$)/0.5% citric acid or fumaric acid, and 50 ppm $ClO_2$/0.5% fumaric acid/blanching at $90^{\circ}C$ for 2 min. Combined treatment of 50 ppm $ClO_2$ and 0.5% citric acid reduced populations of total aerobic bacteria, yeast, and molds in Aster scaber and Cirsium setidens Nakai by 2.80~3.64 and 2.02~2.67 log CFU/g, respectively, compared to those of the control. Combined treatment of 50 ppm $ClO_2$ and 0.5% fumaric acid reduced total aerobic bacteria, yeast and molds populations by 3.62~3.82 and 2.47~3.02 log CFU/g, respectively. Based on the results, combined treatment of $ClO_2$ and fumaric acid was more effective in controlling microorganisms in the wild vegetables than either $ClO_2$ or citric acid. In addition, combined treatment of $ClO_2$/fumaric acid/blanching reduced the populations of total aerobic bacteria by 4.59~5.12 log CFU/g, and populations of yeast and molds were not detected by treatment. These results suggest that combined treatment of $ClO_2$/fumaric acid/blanching is the most effective method for improving microbiological safety of wild vegetables after harvest.