• Journal of Life Science
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• v.12 no.2
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• pp.129-135
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• 2002

Several kinds of thermophilic, aerobic microorganisms (Bacillus genus), metal leaching microorganisms (Thiobacillus, T. ferooxidans), and other nondegradable chemical-degrading microorganisms (Pseudomonas genus) were utilized to study the effect on composting livestock manure. Under the Carbon-Nitrogen ratio (C/N) of 35∼40 and water content of 50∼65% conditions, the composting in the cycling drum reactor showed slower composting and lower temperature increase than that of the manual reactor. Element analysis after composting indicated relatively high levels of mineral contents with the substitutional effect of chemical fertilizer. Metal analysis before and after composting showed lower As in all, Cr in pig, Pb in cow, Hg in chicken, and Cu in cow manure compost than the regulation values. Compost maturity was ascertained by the several maturity tests. Salmonella and E. cozi detection test by SS or EMB agar plate confirmed the safety from the pathogenic microorganisms. The results suggest that the inoculation of metal and some other chemical degrading microorganisms during composting might decrease metal contamination and increase composting rate.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.574-579
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• 2016

This study assessed feasibility of making granular fertilizer with fly ash from a sewage sludge incinerator in Korea. Composition, characteristics, strength, and heavy metal contents of the granular fertilizers were investigated. Due to its high contents of phosphorus, fly ash from a sewage sludge incinerator could be used to make fertilizers. Granulation rates (2-4 mm granules) over 80% could be achieved as the fly ash contents were 15% or less of the fertilizer. Leaching tests of the fertilizers, based upon the Korean Standard Methods for Solid Wastes, showed the concentrations of heavy metals less than the risk limits. However, contents analysis of the fertilizers, based upon the Korean Standard Methods for Soils, experienced higher levels of heavy metals than the risk limits as the fly ash content exceeded 7% of the fertilizer. Thus, the fly ash needs to be added less than 7% of the fertilizer if there is no pretreatment to remove heavy metals.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.13.1-13.5
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• 2013

Objectives: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. Methods: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals - di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)-were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. Results: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were $1.0{\times}10^{-4}$, $1.2{\times}10^{-5}$, $9.5{\times}10^{-3}$, and $5.3{\times}10^{-3}mg/L$ for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were $5.2{\times}10^{-3}$, $6.0{\times}10^{-4}$, $5.0{\times}10^{-1}$, and $2.7{\times}10^{-1}mg/kg$ for DEHP, DINP, Cd, and Pb, respectively. Conclusions: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8292-8296
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• 2015

We manufactured a liqueur containing Cordyceps extract. 21 kinds of the liqueur were manufactured and analyzed the cordycepin content, cordycepin stability and alcohol content. Cordycepin content was detected up to $58{\mu}g/mL$ in DL-3(adding Cordyceps militaris and leached for 3 months). Results of Alcohol content analysis, Methanol was not detected in all samples. Ethanol contents showed at 31.4% from the Leaching process for 3 months after distillation, and at 17.2% from the rice wine adding Cordyceps militaris 8 g. In the results of the Cordycepin content stability analysis, the Cordycepin content decreased during storage period little by little, so our considered opinion is that the cordycepin content should be increased slightly when producing as products.

• Journal of Korean Elementary Science Education
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• v.25 no.4
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• pp.339-351
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• 2006

The purpose of this study was to analyze the processes of observation teaching and the types of observation in elementary life science class. For the purposes of this study, 40 teachers majoring in elementary science education participated in surveys on the processes of observation teaching. In addition, after videotaping the observation classes conducted by three teachers, each teaching in the 3rd to 5th grade, and their one hundred and eight students, we analyzed the processes of observation teaching. As a result, the processes of observation leaching in elementary science class were categorized into 12 stages (motivation, stating the objective, recognizing objects to observe, free and subjective observation, introducing ways to observe, observing by the simple way, introducing additional ways, observing by the manipulative way, making a note of observation, looking over the contents of observation, finding regularities, consolidation). In the types of observation, teachers and students performed mostly simple observing by the visual way. Teachers introduced time-independent/non-compared/whole observing; students concentrated on time-independent/non-compared/particular observing as targets. Thus, students carried out observing in the types of observation that teachers had presented. Consequently, the analysis about the processes of observation teaching can establish an effective teaching program for observing in scientific activities by reconstructing its observing target and suitable topic. The analysis about the types of observation can be applied to set up strategies for improving observation skills.

• Journal of Korean Elementary Science Education
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• v.24 no.4
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• pp.399-416
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• 2005

The purpose of this study was to examine the relationship between science teaching practices and beliefs about the nature of science. Defining teachers' beliefs as a broad construct, the researcher tried to examine not only the teachers' understanding about the nature of science, but also the effect and reflection in science teaching practices with regards to the nature of science. Guiding research questions were how the teachers' science teaching practices reflected their beliefs about the nature of science. The methodology of this study was qualitative approach that included interviews, classroom observations, and instructional materials. At an urban area of Korea, five beginning elementary teacher was chosen. The cross-case and grounded theory study design were adopted as data analysis process. The results of data analysis were checked by teachers for internal validity. This study identified the teachers' beliefs about the nature of science suggested by many researchers and revealed that these teachers' beliefs reflected a little in science teaching practices. On the occasion it was reflected, restricted merely within the narrow limits the way to teach the concepts and contents presented in science curriculum. In addition, some of the obstacles that these teachers' beliefs did not reflect the science teaching practices with regards to the nature of science were investigated in this study.

• Journal of the Korean earth science society
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• v.21 no.4
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• pp.479-487
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• 2000

To investigate the trend of earth science education researches published in ${\ulcorner}$The Journal of the Korean Earth Science Society${\lrcorner}$ during last 20 years, 106 articles were analyzed. The results show that the number of researches in earth science education has increased, especially in recent two years. From the perspective of areas. general earth sciences were studied more than other areas such as astronomy, geology, and meteorology. From the perspective of subjects, students, especially high-school students, were studied more than teachers. From the perspective of research methodology, survey including content analysis of textbooks or curriculum were most preferred. In contrast, literature study were never accomplished. From the perspective of contents, researches of leaching/learning were the most common. It is notable that few studies were about educational assessment or teacher training.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.327-334
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• 2016

In order to compare phosphorus (P) behavior of livestock manure compost (LMC) and chemical fertilizer (CF) applied to the sea-reclaimed land soils, incubation experiments were conducted for five weeks. Four soils differing textural classes, sandy loam and clay loam, and electric conductivity (EC) value, high and low, were applied with CF and LMC. LMC was applied at the level of 0, 1, 2, and 3% on the soil weight basis and CF was applied at the same levels of P as LMC. The results showed that increase of P application rate of CF and LMC led to linearly increase available $P_2O_5$ and $0.01M\;CaCl_2$ extractable P contents regardless of soil texture and EC. However, 0.01M $CaCl_2$ extractable P from soil applied with CF was significantly higher than with LMC. Correlation analysis between $0.01M-CaCl_2$ extractable P and fractionated P by different extraction methods showed that $0.01M-CaCl_2$ extractable P positively correlated with KCl-P (soluble and exchangeable P) and HCl-P (Ca and Mg bound P). However, NaOH-P (Fe and Al bound P and organic P) and residual P was adverse. The amount of NaOH-P significantly influenced to the amount of 0.01M $CaCl_2$ extractable P of CF and LMC in the soils. The application of LMC at sandy loam soil could be carried out in the consideration of nutrient leaching and crop uptake.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.161-169
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• 2000

In this study, the temporal changes in the chemical characteristics of soil in a reclaimed coastal area, the Shihwa Industrial Complex in the West Coast in Kyung-Gi Province, and the correlations between chemical components were investigated to provide useful information needed for introducing vegetation in the area. The sites were filled with mountain forest soils from 1987 to 1996, and developed into various landuses such as neighbourhood parks, children's parks, buffer greens, pedestrian roads and others. The correlation analyses shoed that pH, organic matter(OM) and available P205 had not been closely related to other chemical parameters such as various cations electro-conductivity(EC) and cation exchange capacity(CEC): especially, pH showed a very low correlation with other factors. The EC turned out to have positive relationships with cations, especially with Na+ ions. There seemed to be fairly good correlations between cations except Ca++ ion. The relation between cations and OM was inconclusive possible because the OM contents in the soils were too low for the analysis. The OM seemed to increase slowly with time and the EC decreased slowly. The salinity and CEC in the original soils decreased rapidly possibly because of leaching. It is believed that there were some external disturbances such as rainfall which had affected the soil properties. The soils sampled in dry season showed a very high salinity. From this it is possible to assume that the rainfall would affect the sol properties significantly. So it is necessary to continue further studies to investigate the impacts of external disturbances such as rainfall on vertical soil profile and temporal variations as well as to delineate correlations between parameters with external disturbances controlled.

• Journal of the Korean earth science society
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• v.24 no.8
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• pp.711-720
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• 2003

To study characteristics of the heavy metal pollution, sediment samples were collected at 67 sites on the roadside of Jeonju city during summer and winter, 2002. The total concentration of metals including Cd, Co, Cr, Cu, Ni, Pb, Zn, and Mn in the sediment samples were determined. The results indicate that the roadside sediments in Jeonju city have lower (1/2 to 1/7 times) concentrations of Zn, Cu, Pb and Cd than the metal concentrations previously reported for roadside soil, dust and sewage sludges in Seoul. However, the metal concentrations are higher than environmental quality criteria in soil suggested from several countries, and Zn, Cu, Pb and Cd contents are usually 2-7 times higher than the world average contents of the metals in natural soil. Although pollution index and concentrations of Cr, Ni, Pb and Zn in the roadside sediments at industrial area were usually higher than those of downtown and residential area, the metal having small vehicle- and steel-related industries had high concentrations of metals. The results of chemical partitioning analysis showed that Pb, Zn and Mn are mainly associated with carbonate/adsorbed and Fe-Mn oxide phases but that Cu is largely associated with the organic and sulfide fractions. It thus indicates that both large and small (vehicle- and steel-related) industries are main sources of heavy metal contamination. Due to high solubility of the carbonate phases by natural leaching episodes, the carbonate/adsorbed Cd, Co, Ni, Pb, Zn and Mn in the roadside sediments may serve as a potential source of contamination.