• Journal of Environmental Science International
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• v.17 no.10
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• pp.1139-1146
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• 2008

To investigate the functional properties and the antioxidant effect of pine needle(Pinus densiflora), the pine needle extract was obtained with methanol and its functionality was measured by spectrophotometric method, and the antioxidant experiment on soybean oil was carried out by the active oxygen method. The extraction yield of pine needle with 99% methanol was about 19%, the total flavonoid content of the pine needle-methanol extract was 11.32 mg/g on dry basis and the superoxide dismutase-like activity was 94.3%. The nitrite scavenging ability of the extract was pH dependent with the values of 77.44% at pH 1.2, 48.45% at pH 3.0 and 11.04% at pH 6.0, respectively. The peroxide value was 92.6 meq/kg at 5% dosage, 138.4 meq/kg at 2% dosage of the extract on 8 oxidation days. The period of the peroxide value to be 100 mg/kg was 4.9, 6.3 and 8.5 days at control, 2% and 5% dosage of extract, respectively. And the relative antioxidant effectiveness of the extract was 27.9% and 72.3% increase at 2% and 5% dosage, respectively, compared to control. The thiobarbituric acid value showed few differences within 4 oxidation days, but with the dosage of the extract it fairly decreased with considerable antioxidant effect to control above 4 days.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.5
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• pp.425-430
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• 2000

Physicochemical properties of Kochujang(OK) added onion powder (OK ) were Investigated duringstorage at 20"C The pH value of Kochujang tended to decrease by condition of storage. Initial pH value of OK was significantly lower than that of control, but the difference of pH value was getting smaller during the storage period. In the Process of 90 days storage period, the pH value of OK containing 8 and 10% of onion powder was higher than control. Salt content was lower in OK than in control as the onion content was higher No changes in salt content were observed during the storage process. Reducing sugar was higher in OK than in control, and Its concentration was increased with onion content. Amino acid nitrogen content which was slightly higher in OK than in control increased during 45 days of storage period and tended to decrease afterward. In the sensory attribute data of Kochujang after 3 months of storage period, OK had higher scores in sweetness, color, flavor, and overall acceptability than control, especially the OK with 10% onion powder had the highest scores.scores.

• Advances in environmental research
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• v.5 no.3
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• pp.189-200
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• 2016

This study aimed at advanced oxidation of hetero tri-functional reactive dye Acid orange 7 using photo-Fenton conditions in a lab-scale experiment. Decolourisation of Acid Orange 7 dye by Fenton's process was dependent on concentration of Hydrogen peroxide, Ferrous sulphate, pH, and contact time. A $2^3$ factorial design was used to evaluate the effects of these key factors: pH, Fe(II), and $H_2O_2$ concentration, for a dye concentration of 50 mg/L with COD of 340 mg/L at pH 3.0. The response function was removal of colour under optimised conditions; pH 3.0, [Fe(II)] 40.83 mg/L, [$H_2O_2$] 4.97 mmol/L; 13.6 min. of treatment resulting in 100% colour removal. The final COD of treated wastewater was nil suggesting that AOP is a potentially useful process of color removal and dye degradation/mineralisation of effluent having AO7. Minimum contact time for complete decolourisation was at 5 mmol/l $H_2O_2$ concentration. Increase in $FeSO_4$ (mg/l) concentration resulted in decrease of time for complete decolourisation. Box-Behnken Design was used to optimize the process variables. Maximum and minimum levels of pH (3-5), $H_2O_2$ (4-6 mmol/l), $FeSO_4$ (30-46 mg/l) and contact time (5-15 minutes) were used. The statistical analysis revealed a value of 0.88 for coefficient of regression ($R^2$) indicating a good fit of model. Calculated F-value was found higher than the tabulated value confirming to significance of the model. Based on student's t-test, Ferrous sulphate, pH, and contact time have a positive effect on the percent decolourisation of Acid Orange 7.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.551-558
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• 2007

From the view point of biological wastewater treatment, C/N ratio is one of the most important factor in biological nutrient removal process. However, municipal sewage in Korea is characterized by extremely low content of carbon source and relatively higher portion of N source. Accordingly, it is necessary to dose external carbon source in order to obtain higher degree of carbon source within the process. In this study, the effects of pH pretreatment as an alternative plan for increasing carbon source on the cell disruption and COD solubility of waste activated sludge were conducted under well defined experimental conditions. During 5 hours, the value of COD solubilization rate ($S_R$) at pH 11.5 is approximately 4.4 times higher than the value of $S_R$ at pH 9.5. It is expected that the level of SCOD increased due to the result from cell disruption. However, VSS/TSS ratio was not significantly changed after 5 hours. As Alkalinity changes gradually from less than 15, 30 and 60 meq NaOH/L, average RBCOD/SCOD fraction showed 34, 36 and 45%,respectively.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.73-79
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• 1997

This research was intended as an investigation of applying Reduced Pressure Evaporation as efficient treatment method for landfill leachate. According to the variance of time, temperature, pressure and pH in experiments, the properties of leachate treatment are follows. The removal efficiencies of COD, NH$_{3}$-N, TOC, Conductivity and SS on the basis of reaction time was 96.4%-97.5%, -1.4%-53.7%, 81.7%-89.0%, 92.0%-95.3% and 99.86%-99.97%, respectively. When the pH of Influent was 7.5, the pH of effluent was increased to 10-11 with time elapse. It is concluded that the orgin of pH increase may be ammonia. When the properties of concentrate were investigated at the concentration ratio 90%(V/V), concentration difficiency represented in the ratio of experimental value/calculated value had following orders ; COD>TOC>NH$_{3}$-N>Conductivity>SS. Concentrate had good precipitation because of additive thermal treatment in the process. When evaporation experiments with pH adjustment of 4.0, 6.0, 7.5, 9.0 and 10.0 were performed ; Acidic evaporation experiments(pH 4.0, 6.0) showed low removal efficiency(81.6, 87.6%) of COD and high removal efficiency (97.5%. 84.6%) of NH$_{3}$-N at initial evaporation. Basic evaporation(pH 9.0, 10.0) showed high removal efficiency (97.2%, 98.9%) of COD and very low removal efficiency (-7.4%, -27.2%) of NH$_{3}$-N at initial evaporation.

• Journal of Environmental Health Sciences
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• v.12 no.1
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• pp.1-14
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• 1986

This investigation was carried out on the study of Ferrite formation by aerial oxidation of Fe $(OH)_2$ suspension of aqueous solution containing heavy metal ions. In this study the optimum reactionary condition of the Ferrite formation in Batch reactor wa studied by aerial oxidation which are subjected to various reaction time and temperature, under the different kinds of R(2NaOH/$FeSO_4$) Values, pH, Air flow rate, and $Fe^2+/M^2+$ mole ratio. The optimum condition for the Ferrite formation in Batch reactor was such that residence Time was 90 min., Temperature $65{\circ}$C, pH 11.0, Air flow rate 2.0l/min and $Fe^{2+}/M^{2+}$ mole ratio 4.0, which was observed by X-Ray diffraction analysis. The relation R-value, pH and ORP affecting the formation of Ferrite is that the jump step in pH 11.0, when a amount of NaOH is added, is steady state to the formation of Ferrite. Effect of R-value of $FeSO_4$ and $FeCl_2$ on the formation of Ferrite in different from each other the optimum condition of the in different from each other the optimum condition of the $FeCl_2$ is R-value 0.7, pH 11.0 and the $FeSO_4$ R-value 1.2, pH 11.0.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1307-1313
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• 2002

This study was performed to investigate the single and combined effect of concentrations of garlic juice according to the pH and temperature on the growth of Salmonella enteritidis in brain heart infusion broth, and to develope Response surface model for the effect of concentrations of garlic extract. The results of electric conductibility of Salmonella enteritidis growing in the range of incubation temperature ($25~42^{\circ}C$), pH (5.5~9.0) and concentration of garlic Juice (0~0.8%) showed that a badge with high temperature had low D.T.value and concentration of garlic extract were significantly correlated with D.T.value (p<0.01). Growth of Salmonella enteritidis in the condition of $37^{\circ}C$ and pH 7.0 presented the lowest D.T.value.

• Journal of Korean Port Research
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• v.10 no.2
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• pp.69-90
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• 1996

This study is related to save the bearing capacity from using Meyerhof formula namely, static mechanics formula with the S.P.T(N value) of the soft ground and is to choose the soft ground improvement method by the using of total load for the proper method of the pile foundation and then to design the most suitable pile foundation to fit the actual circumstance. The purpose of this study is calculating the diameter of the pile foundation by static mechanics formula and introducing the optimum design condition from the result of the bearing capacity for using N value of the S.P.T obtained from the deep soft ground about the piles such as P.H.C pile, pipe and cast-in-place pile of big diameter, etc. As above-mentioned, it is considered that the use of P.H.C pile or pipe pile is advisable on the synthetical investigation and that the selection of cast-in-place pile method is desirable in terms of the constructive safety and durability.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.297-302
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• 2005

Physicochemical properties were compared between freeze concentrated and vacuum evaporated milk through colour, brix, viscosity, freezing point and pH measurement. Brix and viscosity in each concentrated milk significantly increased due to solute concentration(p<0.05), and there was not much difference between freeze concentrated and evaporative one. Brix results were numerically modeled with the logarithmic regression: Y=-33.460+18.4513 ${\cdot}$ ln(X), $R^2=0.9798$ and this model was fairly fit to predict the solute concentration in the middle of freeze concentration process. Freezing point significantly decreased according to concentration increment(p<0.05) and there was not the significant difference between freeze concentrated and evaporated one. Whereas, in colour and pH value, there were some differences between freeze concentrated and evaporative milk. Vacuum evaporated milk expressed higher discoloration comparing to freeze concentrated one. In pH values, evaporated milk showed the significantly decreased results comparing to freeze concentrated sample, whereas the pH value of freeze concentrated sample expressed the similar value to the reference milk.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.227-236
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• 2009

The purpose of this study is to examine the acidity of beverages that are sold for children in the market and to estimate by experiment the degree of the enamel erosion of deciduous teeth that is attributed to the beverages. The pH value of children beverages among top sale list in Seoul and Gyeonggi province were measured. And 7 beverages with the pH value of 3.5 or lower were selected. The enamel erosion of deciduous teeth by the children beverages for 1, 5, 10, and 30 minutes respectively was examined. The results were as follows: 1. The acidity of most of the children beverages examined in this study was the pH level of 5.5 or lower that can cause the tooth erosion. 2. The microhardness value of the enamel of deciduous teeth was lower as exposing it to children beverages. The reduction of surface microhardness value was significant from 1 minute after the exposure, and the reduction was continuously observed until 30 minutes has passed. 3. The higher the acidity of beverages, the larger the reduction in microhardness value caused after the exposure of 30 minutes to the beverages. There was no significant relation between the acidity of beverages and the reduction rate of surface microhardness value. The other factors such as calcium, phosphorus, and fluorine or buffering of the beverages may affect the enamel erosion.