• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.186-190
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• 2004

The electrokinetic bioremediation employing electrolyte circulation method was carried out for the cleanup of phenanthrene-contaminated kaolinite, and microorganism used in the biodegradation of phenanthrene was Sphingomonas sp. 3Y. The electrolyte circulation method supplied ionic nutrientsand the microorganism into soil, and inhibited the significant pH change of soil by increasing the soil buffering capacity by providing phosphate buffer compounds. When the remediation process was conducted without surfactant, the removal efficiency of phenanthrene, at the initial concentration of 200 ppm, was 69% for only 7 days. Higher microbial population and lower phenanthrene concentration were observed in the anode and middle regions of soil specimen than in the cathode region. The higher density of microorganism was because the microbial movement was in the direction of the anode part due to the negative surface charge. When Triton X-100 and APG of 20 g/1 were used to improve the bioavailability of phenanthrene strongly adsorbed onto soil surface, about 90 and 39% of phenanthrene removal were obtained. Consequently, it was confirmed that the microorganism preferred APC to phenanthrene as carbon source and so the removal efficiency with APG decreased less than that without APG.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.743-746
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• 2000

The possiblity of sepiae os as a calcium supplement in food was studied. Elementary contents of sepiae os were as follows; Ca 53.254%, O 26.781%, Na 14.905%, Cl 4.37%, Sr 0.507%, P 0.068% and Si 0.051%, respectively. Most of calcium in sepiae os was present as a form of CaCO3. Sruface area of sepiae os was found as 386 m2/g, and scanning electron micrograph showed sepiae os has multilayer struture. Buffering capacity of sepiae os that of CaCO3. With above results, sepiae os can be used as a calcium supplement in food with good chacterateristics.

• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.173-177
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• 2000

The synthetic carbon was coated with tin oxide and copper by fluidized-bed chemical vapor deposition method. $(CH_3)_4Sn\;and\;Cu(hfac)_{2s}$ were employed as the metallic organic precursor, respectively. The modified synthetic carbons were used for lithium secondary battery anode to investigate their coating effects on electrochemical characteristics as alternative anode materials for lithium secondary batteries. The electrode which prepared by the synthetic carbons(MCMB) coated with tin oxide gave the higher capacity than that of raw material. Their capacity decreased with the progress of cycling possibly due to severe volume changes. But the cyclability was improved by coating with copper on the surface of the tin oxide coated carbon, which plays an important role as an inactive matrix buffering volume changes.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.130-139
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• 2007

This study investigated the relationship between dental caries and various oral factors in subjects with Down's syndrome. We compared 25 subjects with Down's syndrome with 63 healthy control. The dental caries index and plaque index were examined, and the total salivary immunoglobulin A and S. mutans specific salivary immunoglobulin A concentration were measured using ELISA. The S. mutans counts, Lactobacillus counts and buffer capacity were measured with Dentocult test medium. The decayed and filled surface index of deciduous teeth in subjects with Down's syndrome was lower than in controls(p<0.001). The plaque index and total salivary immunoglobulin A concentration showed no difference, S. mutans specific salivary immunoglobulin A concentration and buffer capacity in subjects with Down's syndrome were lower than in controls(p<0.001). There was no significant difference between two groups in the S. mutans counts and Lactobacillus counts. In 9-11 year age group, S. mutans counts in subjects with Down's syndrome was lower than in controls(p<0.001) and S. mutans specific salivary immunoglobulin A concentration was lower(p<0.05). There was a high correlation among deciduous dental caries index and buffering capacity and S. mutans counts.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.256-264
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• 2018

The purpose of this study was to investigate the relationship between oral health behaviors and the results of the oral dysentery test for dental hygienists and students at Gyeonggi - do and Chungcheongnam - do. Self - filling questionnaires and oral diseases. The following conclusions were obtained. The most common toothbrushing frequency was three times a day (60.2%), and the most dominant frequency of eating between meals was once or less(49.7%). The most common snack that they had was stickiness-free sweetened food(66.5%), and the type of beverage that they had the most was sweetened beverages(49.7%). The average stimulated saliva flow rate was 9.41ml, and they got a mean of 9.52 in the buffering capacity of saliva. The average glucose clearance time was a mean of 12.02. When they took a streptococcus mutans colony count test, 80.1 percent belonged to the low-risk group(<$10^5$), and 82.6 percent belonged to the low-risk group(<$10^5$) when a lactobacillus test was conducted. There was a positive correlation between the irritant saliva fraction and the non-irritating saliva and saliva buffering ability. In the fluoride application experience, the glucose retention time was 10.66 minutes and the fluoride application experience was 13.33 minutes. (P = .008). The importance of oral health, which is directly linked to general health, should be emphasized in order to improve the quality of life as well as the life expectancy. For oral health, which is directly linked to systemic health, it is necessary to provide opportunities for oral health education that can be easily accessed by the public, and to continuously develop and provide oral health care programs for a lifetime.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.362-371
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• 2012

Objective of this research was to secure the information on physical and chemical properties of peatmoss and coir dust. To achieve this, 6 kinds of peatmoss and 10 kinds of coir dust currently used in the country as the root medium components in plant factories were collected and analysed. The mean ${\pm}$ standard deviation (SD) of total porosity and container capacity in peatmoss and coir dust were $79.6{\pm}5.04$ and $83.6{\pm}6.18%$, and $69.9{\pm}10.17$ and $65.9{\pm}3.46%$, respectively. These indicate that peatmoss has higher water holding capacity than coir dust and the characteristics are highly varied among peatmoss. The 4 out of 5 kinds of peatmoss had lower than 10%, but coir dust had 12~26%, of air-filled porosity. The percentage of easily available water and buffering water in peatmoss and coir dust was 18~22 and 11~16% and 9~13 and 5.5~7.5%, respectively. These results indicate that precise irrigation is required when coir dust is used as the root medium. The ranges of pH and electrical conductivity (EC) were 3.46~4.17 and $0.137{\sim}0.253dS{\cdot}m^{-1}$ in peatmoss and 5.31~6.48 and $0.250{\sim}0.1.580dS{\cdot}m^{-1}$ in coir dust. However, $0.563{\pm}0.83dS{\cdot}m^{-1}$ in mean ${\pm}$SD of coir dust EC indicates that it is higher than that of peatmoss, and the coir dust are highly varied in EC. The cation exchange capacity of peatmoss was 3 to 4 times as high as that of coir dust. The coir dust had higher $NO_3$ and $PO_4$ and lower $NH_4$ than peatmoss. The K and Na concentrations in coir dust were extremely high indicating that these ions caused the rising in EC. The percentage of hot water and alkali extracts of peatmoss were 6.67~16.37 and 0~38%, whereas those of coir dust were 30.0~65.1 and 23.1~70.3%. These results mean that possible existence of growth inhibiting materials in coir dust.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.55-58
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• 2004

The objective of this study was to get information about water retention characteristics of horticultural substrates used in Korea determined by European standard method. Water retention curves were prepared at water volume (v/v, %) in relation to -10 cm, -50 cm, -100 cm water pressure head. Water retention curves showed different properties depending upon the type, the place of origin, particle size, and manufacturing processes of substrates. Peat and coir had easily available water content in the range of 30-40% and showed high water holding capacity, water buffering capacity, and aeration for plant growth. However, bark, sawdust and rice hull showed low water holding capacity about below 10%. The easily available water content of perlite and clay ball was low about 0.1-13.8%, whereas that of vermiculite and rockwool granulate was high about 25.9-52.0%. Understanding water retention characteristics of growing substrates is very important in cstablisliing optimum condition for plant growth. Further study on water retention curves for more substrates, mixture and growing media is needed.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.249-258
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• 2019

Acid spill accidents are frequently occurring in Korea with increasing production, use, storage, and transport of acids, accompanying industrialization and economic growth. The acids introduced to the subsurface environments would eventually be neutralized by reactions with geomedia. However, the spatial and temporal extent to which the spilled acids would affect will be dependent on the characteristics of the geomedia exposed to the acids. In this work, sulfuric acid, the most used acid in Korea, was reacted with a set of model geomedia representative of the geology of Korea. The buffering capacity of the model geomedia was determined through batch-type experiments using pH changes as an indicator. X-ray diffraction was used to identify the mineral phases contributing to the acid neutralization. The results showed that sandstone had the largest acid neutralization capacity among the tested geomedia, while kaolinite had the smallest. The findings of this study would contribute to quantitatively assessing the impact of spilled acids on geomedia and hence to predicting the vulnerability of geomedia to the spilled acid.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.112-122
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• 2023

To restore the ecological function of contaminated soil and maximize the ecological services provided by the soil, besides the toxicity orrisk caused by pollutants, the functional aspects of the soil ecosystem should be considered. In this study, a method for evaluating the health of cleaned soil was presented, and the applicability of the proposed evaluation method was examined by applying it to soil treated with washing and landfarming. Productivity, habitat, water retention capacity, nutrient cycling, carbon retention capacity, and buffering capacity were used as soil health evaluation indicators. The results showed that the soil health was not completely recovered after remediation, and even in the case of the washed soil, the health was lower than before remediation. On the other hand, there was no significant change in soil quality due to oil pollution, but soil health deteriorated. Unlike the slightly improved soil quality after landfarming treatment, soil health was not completely restored. Therefore, the results of this study indicate that it is desirable to consider both soil quality and health when evaluating the remediation effect. The soil health evaluation method proposed in this study can be usefully utilized for the sustainable use of cleaned soil and to promote ecosystem services.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.39-46
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• 2008

The purpose of this study was to assess the cariogenic potential of infant confectionaries. In vitro, as compaired with 10% sucrose solution and whole bovine milk. Buffering capability were determined by amount of 0.1N lactic acid consumed to titrate the 50ml specimen solutions to pH 4.0. The pH of the specimen solution inoculated by streptococcus mutans was measured by pH meter and the surface microhardness tester, before and after 48 hours incubation. The buffering capacity of infant confectionaries was higher than that of sucrose solution and lower than that of milk, and there were significant difference between infant confectionaries(p<0.05). The pH of infant confectionaries after 48 hours incubation was similar to 10% sucrose solution, and there were significant difference between infant confectionaries and milk(p<0.05). The microhardness change of primary tooth enamel of infant confectionaries group after 48 hours incubation was similar to that of 10% sucrose solution, and there were significant difference between infant confectionaries and milk(p<0.05). In conclusion, infant confectionaries seemed to have the ability to cause dental caries in primary teeth, and there were significant differences of cariogenic potential among infant confectionaries. Cooperative efforts of dentistry and manufacturers to reduce the cariogenic potential of infant confectionaries would be necessary to prevent the early childhood caries in children.