• Journal of the Korean Chemical Society
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• v.50 no.6
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• pp.454-463
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• 2006

refractory organic compounds in aqueous solution are not readily removed by the existing conventional wastewater treatment process. In recent years, the sonolysis and electrochemical oxidation process had been shown to be promising for wastewater treatment due to the effectiveness and easiness in operation. This study was performed to investigate the characteristics of sonolytic and electrolytic decomposition as the basic data for development of the wastewater treatment process. Trichloroethylene(TCE) and 2,4- dichlorophenol(2,4-DCP) were used as the samples, and their destruction efficiency were measured with various operating parameters, such as initial solution concentration, initial solution pH, reaction temperature, sonic power and current density. Also, the decomposition mechanism conformed indirectly with the effect of NaHCO3 as a radical scavenger on the decomposition reaction. Thermal decompositon reaction is predominant for TCE but thermal and radical decompositon reactions were dominant for 2,4-DCP. Results showed that the destruction efficiencies of all samples were above 65% within 120 minutes by sonolysis and electrolysis at the same time, and were increased with increasing initial concentration, sonic power and current density. Destruction efficiency of TCE was high in the acidic solution, but 2,4-DCP showed high destruction efficiency in basic solution.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.228-233
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• 2000

This study was carried out to estimate the possibility on the removal of phenols and anilines, which were contained in pulp or dye waste water, and the reusability of plant materials, shepherd's purse and turnip. Most of phenols catalyzed with shepherd's purse were removed more than 90% in the presence of $H_2O_2$, and the removal was ranged from 53.1% for 2,6-DMP to more than 99% for 2,4,6-TCP when turnip was used as catalysts. The removal of anilines catalyzed with shepherd's purse was ranged from 42.2% for 2-CA to 78.7% for 3,4-DCA in the presence of $H_2O_2$, and in case of turnip, from 31.5% for 2-CA to 90.0 % for 2,4-DCA. The reuse of plant materials was proved to be possible for not only the batch method but also the continuous method. No decreasing removal was observed during 30 cycles in waster water contaminated with 100ppm of 2,4-DCP. However, it was observed that the removal was decreased with increasing the number of cycles in higher concentration of 2,4-DCP(800ppm). Therefore, it could be suggested that the number of reusable cycles depends on the initial concentration of substrates.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.7-13
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• 2006

The effects of electrolytes were investigated on the removal efficiency when several different electrolytes were used to change the electrode reaction in an electrokinetic (EK)-Fenton process to remediate phenanthrene-contaminated soil. Electrical potential gradient decreased initially due to the ion entrance into soil and then increased due to the ion extraction from soil under the electric field. Accumulated electroosmotic flow was $NaCl>KH_2PO_4>MgSO_4$ at the same concentration because the ionic strength of $MgSO_4$ was the highest and $Mg(OH)_2$ formed near the cathode reservoir plugged up soil pore to inhibit water flow. When hydrogen peroxide was contained in electrolyte solution, removal efficiency increased by Fenton reaction. When NaCl was used as an electrolyte compound, chlorine ($Cl_2$) was generated at the anode and dissolved to form hypochlorous acid (HClO), which increased phenanthrene removal. Therefore, the electrode reaction of electrolyte in the anode reservoir as well as its transport into soil should be considered to improve removal efficiency of EK-Fenton process.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.175-179
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• 2005

To develop a high efficiency plant regeneration system from in vitro cultures of strawberry, cv. Yeobong, petiole and leaf explants were cultured on MS basal medium containing a combination of 0.5 mg/L IBA and 3.2 mg/L kinetin or zeatin or benzyl amino purine (BAP) for 6 weeks, and leaf explants with dark pretreatment for a week ($T_1$), 2 weeks ($T_2$), and 4 weeks ($T_3$) were cultured on medium supplemented with 0.5 mg/L IBA and 3.2 mg/L zeatin under 16 hr photoperiod for 6 weeks. Shoot organogenesis was observed from the greenish calli containing minimal anthocyanin formed at proximal cutting edges of the leaf explant (57%) when cultured adaxial side on the medium, whereas was directly formed from a cutting edges of petiole explant (6.3%). Frequency of callus formation and shoot organogenesis at large size of leaf explant ($1.0{\sim}1.5\;cm^2$) was higher than small size ($0.5{\sim}1.0\;cm^2$), and dark pretreatment significantly improved the frequency of leaf explants that produced calli and shoots. The maximum frequency (87%) for shoot organogenesis was obtained from the leaf explants that transferred to a 16 hr photoperiod condition after the initial 4 weeks dark period. The improved frequency (87%) in comparision with control without dark pretreatment (27%). When the shoots were transferred to 1/2 MS basal medium, formed roots with 20 d of culture. The rooted plants were subsequently transferred to the pots and to the field.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.159-167
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• 2000

In recent years, combined and separated sewer overflows (CSOs, SSOs) have been recognized as a significant pollution problem. To solve this problem a series of experiments were performed in a small scale Rapid Floc Settler (RFS) device to determine its ability in removing micro particles and dissolved materials from polluted waters. The RFS device is a compact physico-chemical wasterwater treatment system. Polyacrylamide (PAM) is used as a coagulant for treating stormwater in the RFS. The results of Jar test showed that PAM could be an excellent coagulant as compared with aluminum sulfate. and ferric chloride. In several experimental conditions, the influence of different variation parameters was tested to measure the efficiency of the RFS. Tests have been carried out with typical CSOs concentrations (50~1.000mg SS/L). The treatment efficiency with regard to SS and COD, which can be obtained at an overflow rate of $130m^3/m^2/day$, are 90% and 80%, respectively. Comparing other sedimentation technologies with RFS, the overflows rate of RFS is ten times faster. The distribution of particle size and number were analyzed. The RFS is suitable for the treatment of CSOs and also the removal of settleable and dissolved materials in urban stormwater runoff.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.329-337
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• 2013

This study was performed to evaluate the temporal and spatial variations of the water quality at stream flowing into the Suncheon bay in Suncheon city from October 2008 to August 2009 and to estimate the pollutant sources from the streams using multivariate analysis. Water qualities from Seo stream, Dong stream, Ok stream were evaluated as I grade(very good) that compared to the Water Quality Standard. But Haeryong stream and inlet site of Suncheon Bay in BOD were evaluated as a little bad and fair. Water quality at the stream flowing into the Suncheon Bay was could be explained up to 92.8% by three factors which were included in loading of nutrients, organic matter and total coliform group by the allochthonous matters(53.7%), Topographic Factors(25.0%), seasonal variation(14.2%). The concentrations of total nitrogen and phosphorus at sewage treatment plant and organic matters at Haeryong stream were higher than that of others, respectively. From principal component analysis and factor analysis, it could be suggested that it is very important to make an effort to reduce the nutrients and organic matters from sewage treatment plant and Haeryong stream to be in good conservation of the Suncheon bay.

• Applied Biological Chemistry
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• v.23 no.1
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• pp.64-72
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• 1980

Industrial wastes from pulp and food plants were treated with microorganisms to clarify organic waste-water and to produce cells as animal feed, and results were summarized as follows. (1) Waste-water from pulp, beer, bread yeast, and ethanol distillation plants contained $1.4{\sim}1.5%$ of total sugar, $0.25{\sim}0.35%$ nitrogen, and biological oxygen demand (BOD) was $400{\sim}25,000$, chemical oxygen demand (COD), $500{\sim}28,000$, and pH, $3.8{\sim}7.0$. The BOD and COD were highest in waste-water from ethanol distillation plants among others. (2) Bacterial and yeast counts were $4{\times}10^4-1{\times}10^9,\;2{\times}10^2-7{\times}10^4/ml$ in waste-water. (3) Bacteria grew better in pulp waste and yeasts in beer, bread yeast, and ethanol distillation waste. (4) Saccharomyces cerevisiae SAFM 1008 and Candida curvata SAFM 70 were the most suitable microorganisms for clarification of ethanol distillation waste. (5) When liquid and solid waste from ethanol distillation were treated with microbial cellulase, xylanase, and pectinase, solid waste was reduced by 36%, soluble waste was increased, and recuding sugar content was increased by 1.3 times which provided better medium than untreated waste for cultivation of yeasts. (6) Optimum growth conditions of the two species of yeast in ethanol distillation waste were pH 5.0, $30^{\circ}C$, and addition of 0.2% of urea, 0.1% of $KH_2PO_4$ and 0.02% of $MgSO_4$. (7) Minimum number of yeast for proper propagation was $1.8{\times}10^5/ml$. (8) C. curvata70 was better than cerevisae for the production of yeast cells from ethanol distillation waste treated with microbial enzymes. (9) S. cerevisiae produced 16 g of dried cell per 1,000ml of ethanol distillation waste and reduced BOD by 46%. C. curvata produced 17.6g of dried cell and reduced BOD by 52% at the same condition. (10) Yeast cells produced from the ethanol distillation waste contained 46-52% protein indicating suitability as a protein source for animal feed.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.70-81
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• 1988

To measure the birth registration rate and the validity of birth registration data in rural area, all of the 4,014 married women under 49 years of age who had not been sterilized in Gunwee county of Kyungpook province were followed by Myun health workers for 2 years from April 1, 1985 to March 31, 1987 and 766 births were detected. All of the birth registration records of Myun offices were reviewed on September 30, 1987 and 944 births which occurred within the above mentioned period were found. Actual birth date obtained by follow-up study were compared with the birth date on registration card. Among 766 births detected by follow-up study,576 births(75.2%) which were reported within 6 months after birth were ascertained on the official registration records and 96 births(12.5%) were not found on the records although mother stated that the birth was registered. The registration rate within legal due date was 61.3% among 576 births detected by follow-up study and also ascertained on the official records. The registration rate within legal due date was lower in mothers under 20 years of age and above 35 years and in mothers who had only primary education. It was decreased as the birth order increased. The registration rate was higher in births occurred from October to March than births occurred from April to September. All of the births of 7 neonatal deaths were not reported. The registered birth date was consistent with the actual birth date in 78.0%. Birth date on record was earlier than the actual birth date in 6.8% and later in 15.3%. The consistency rate was lower in mothers above 35 years of age(54.5%), and in infants of 4th birth order and above(56.3%). The rate was increased as the maternal education level increased. The rate of boys was higher than that of girls. A higher percentage(17.4%) of infants born in March was registered with earlier date than the actual birth date and most of these registered birth dates were lunar calendar date. This might be related with the age for entering the primary school. The study findings revealed that the birth registration rate within legal due date and accuracy of report have been increased in recent years, but the infant mortality rate derived from the birth registration seems to be very inaccurate. It is suggested to let the medical personnel who delivered the baby report the birth by mail directly to the current address of parent while infants delivered at home without professional attendant may comply with the present registration system.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.65-70
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• 2009

Reduction of groundwater surface tension prior to air sparging (SEAS, surfactant-enhanced air sparging) was known to increase air saturation in the aquifer under influence, possibly enhancing the removal rates of volatile contaminants. Although SEAS was known to be efficient for increasing air saturation, little information is available for different hydrogeological settings including soil particle sizes and the depth of aquifer. We investigated water saturations in the sparging influence zone during SEAS using one-dimensional column packed with sands of different particle sizes and different aquifer depths. An anionic surfactant was used to suppress the surface tension of water. Two different sands were used; the air entry pressures of the sands were measured to be $15.0\;cmH_2O$, and $36.3\;cmH_2O$, respectively. No significant difference was observed in the water saturation-surface tension relationship for sands with different particle sizes. As the surface tension decreased, the water saturation decreased to a lowest point and then it increased with further decrease in the surface tension. Both sands reached their lowest water saturations when the surface tension was set approximately at 42 dyne/cm. SEAS was conducted at three different aquifer depths; 41 cm, 81 cm, and 160 cm. Water saturation-surface tension relationship was consistent regardless of the aquifer depth. The size of sparging influence zone during SEAS, measured using two-dimensional model, was found to be similar to the changes in air saturation, measured using one-dimensional model. Considering diverse hydrogeological settings where SEAS to be applied, the results here may provide useful information for designing SEAS process.

• Journal of Nutrition and Health
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• v.48 no.4
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• pp.352-363
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• 2015

Purpose: Despite the popularity of dietary supplements, little data are available on their use by university students. The purpose of this study was to examine the use of vitamin mineral supplements and to identify factors related to supplement use among university students. Methods: University students (N = 345) in Seoul were surveyed. Survey questions included descriptive demographics, types of vitamin and mineral supplements used, health related lifestyle factors, mini dietary assessment, and knowledge and behaviors related to supplement use. Results: Of university students surveyed, 41% consumed vitamin and mineral supplements. Among the supplement users, multivitamins were the most commonly used dietary supplements (68.6%), followed by vitamin C (31.4%) and calcium (17.1%). In particular, the use of vitamin C and iron supplements was more common in females than males (p < 0.05). For the number of supplements taken daily, 32.1% of supplement users consumed 2 or more supplements; 20% of supplement users had almost no knowledge of the supplements being taken. Based on the results of multivariable logistic regression analysis, supplement use was associated with higher interest in their own health, non-smoker, and supplement use by family (p < 0.05). In addition, supplement use was slightly associated with healthy dietary behavior such as consuming a variety of foods (p = 0.05) and current disease status (p = 0.05). Conclusion: University students with relatively healthy lifestyles appear to take vitamin and mineral supplements, but they had little knowledge of the supplements. Given high prevalence of dietary supplement use among university students, nutrition education regarding supplement use is needed.