• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.234-239
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• 2015

Various leaching tests were applied to the soil affected by accidental leakage of HF in an industrial area in Korea. Three different leaching methods including pH-stat, continuous batch leaching, and column tests were adopted to assess leaching characteristics and mobility of fluorine(F) in soil and the potential risks to ecosystem. Both natural and spiked samples were used for the leaching tests. F concentrations in the batch tests increased by leaching rapidly in the early stage of leaching and then maintained rather constant levels. Column leaching test also show similar result to that of the batch test. pH also controlled the leaching behavior of the soil. With increasing pH, more F was released in the pH-stat test. This is mainly due to the competition and exchange with hydroxyl ions, as pH increase to the alkaline range. Most of the F released by the accident seem to have removed in the very early stage of leaching, whereas some natural proportion from soil minerals are thought to have been released very slowly. Therefore, little F released during the accident remained, based on the results of this study on the samples after two years of the accident. We could conclude that soil contaminated by external effects such as chemical accidents should be managed immediately, especially with F.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.55-62
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• 1996

The purpose of this study is the evaluation of adsorption capacity of casts for heavy metals comparing with the activated carbon. The casts was obtained from vermicomposting of the mixed organic sludges which were generated from the treatment facilities for leather wastewater and cattle wastewater. The physico-chemical characteristics of cast was investigated. Also, the batch adsorption experiments of cast and activated carbon for heavy metals were carried out, and the results were analyzed by Freundlich isotherm. The buffering capacity to the acidic wastewater was founded in the cast, and the cation exchange capacity of cast impling adsorption capacity for soluble substances was evaluated as about 55me/100g. Those were implied that the cast have a large potential as a good adsorbent for soluble pollutants in wastewater. From the results of batch experiments, the removal efficiencies of tested various heavy metals including Pb, Cu, Cd, and Cr were very high value as 89-98% for the activated car-bon, and 80~95% for the casts except for Zn. The adsorption equilibriums for the two materials were achieved within 90 minutes. The order of preferable metals in the adsorption was found to be Pb>Cu>Cd>Cr>Zn on the cast and to be Pb>Cd>Cu>Cr>Zn on the activated carbon, respectively. From the above results, it might be con-cluded that cast is effectively available as a good adsorbent to treating the heavy metal bearing wastewater.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.424-433
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• 2019

The purpose of this study was to evaluate the salivary concentration of Potassium and Magnesium cations and their variation before and after sucrose and glucose rinse, and to investigate the relationship between the levels of each compound. Saliva samples were obtained from 40 subjects before and up to 60 min after intake of a 10% sucrose and glucose solution at 1-month intervals. Potassium and Magnesium in human saliva were determined via anion-exchange chromatography with an anion-suppressed conductivity detector using 12 mM sulfuric acid. The concentrations of Potassium and Magnesium before sucrose rinse were 274.3±77.9 mg/ℓ and 4.5±2.5 mg/ℓ, also, the concentrations of Potassium and Magnesium before glucose rinse were 279.2±62.1 mg/ and 4.8±2.0 mg/ℓ, respectively. Potassium and Magnesium concentrations were significantly decreased (p<0.05) after sucrose rinse. The content of potassium and magnesium in saliva before and after rinsing sucrose and glucose is difficult to standardize or classify, as previous research. The reason for the variation between individuals is large, and easily changed by chemical or physiological stimulation. However, this study was experiment for the purpose of accumulating basic data for saliva.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.237-241
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• 1992

The protease from Halomonas sp. ES 10 was purified by methanol precipitation, gel filtration on Sephadex G-150 and G-200, and ion exchange chromatography on DEAE-Sephadex A-50. The purified enzyme was found to be homogeneous by polyacrylamide gel electrophoresis. The specific activity of purified enzyme was 1,014 units/mg protein, and the yield of the total activity from the culture filtrate was 7%. The optimal temperature and pH for the enzyme activity were $35^{\circ}C$, and pH 11.0, respectively. And the enzyme was stable in the range of $pH\;7.5{\sim}11.0$. The residual activity of the enzyme was 70%, when the enzyme was incubated at $50^{\circ}C$ for 40 min. The Km value of the enzyme was 7.4 mg/ml to milk casein. $Li^+$, $Ca^{2+}$, SDS and Tween 80 were appeared to activators, whereas $Hg^{2+}$ and EDTA to inhibitors. The addition of DFP and PMSF showed the relative enzyme activities of 63% and 107%, respectively, suggesting that the enzyme may not belong to serine type protease. When the alkaline protease was treated with 0.5 M and 1 M NaCl, the relative enzyme activities were 95% and 65%, respectively. This enzyme showed 20% and 15% higher enzyme activity than that of Aspergillus oryzae (Sigma Chemical Company product, P4755) in the presence of 0.5 M and 1 M NaCl.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.453-462
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• 2000

This study was carried out to know the effect of urea addition for composting of paper mill sludge(PMS). For the purpose. PMSs containing 0%, 1.5%, 3%, and 6% urea were composted at aerated static pile(ASP) for about 80day periods. During the composting, the basic physical, chemical, and biological parameters such as temperature, color. C/N ratio, cation exchange capacity, and phytotoxic test were investigated. From the measurement of the parameters, 0~3% urea-containing PMS except for 6% urea-containing PMS showed to be normally stabilized. Thus among these treatments, 0% and 3% urea-containing PMS were applied at agitated bed system(ABS), a pilot plant of a large scale, to evaluate the possibility of practical use. Considering to the changes of the parameters investigated during composting in ASP and ABS, PMS showed to be successfully stabilized in the two facilities. However, when composted with PMS and urea, even the final PMS compost stabilized for a period enough brought out the bright grayish color. So it may be necessary to add a subsidiary amendments such as animal manure to form brown-colored products.

• Membrane Journal
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• v.30 no.3
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• pp.173-180
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• 2020

As the demand for fossil fuels continues to increase worldwide, carbon dioxide (CO₂) concentration in the air has increased over the centuries. The way to reduce CO₂ emissions to the atmosphere, carbon capture and sequestration (CCS) technology have been developed that can be applied to power plants and factories, which are primary emission sources. According to the climate change mitigation policy, direct air capture (DAC) in air, referred to as "negative emission" technology, has a low CO₂ concentration of 0.04%, so it is focused on adsorbent research, unlike conventional CCS technology. In the DAC field, chemical adsorbents using CO₂ absorption, solid absorbents, amine-functionalized materials, and ion exchange resins have been studied. Since the absorbent-based technology requires a high-temperature heat treatment process according to the absorbent regeneration, the membrane-based CO₂ capture system has a great potential Membrane-based system is also expected for indoor CO₂ ventilation systems and immediate CO₂ supply to smart farming systems. CO₂ capture efficiency should be improved through efficient process design and material performance improvement.

• The Korean Journal of Mycology
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• v.20 no.4
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• pp.324-336
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• 1992

On the five interspecific protoplast fusants of Ganoderma lucidum and G. applanatum was the antitumor test performed. The fusant F-2 was selected, to examine the cultured mycelia (protein bound polysaccharide) as antitumor components. When a dose of 20 mg/kg/day of each components purifed from F-2 fusant was, i.p., injected into ICR mice, the inhibition ratio of Fr. II against the solid form of sarcoma 180 increased to 1.5 times as compared with that of their parents. When Fr. II was examined for immunopotentiation activity, it increased the amount of the superoxide anion in activated macrophages to 1.2 times and the count of hemolytic plaque forming cells in the spleen to 4.3 times as compared with that of each control group. Its chemical analysis showed 85.2% polysaccharide which consisted of glucose, galactose, mannose, fucose and xylose, and 0.39% protein of 15 amino acids. The content of hexosamine was 0.39% and the molecular weight of Fr. V was $5.6{\times}10^4$ dalton.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.146-154
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• 2002

To assess the adsorption and removal mechanism of dissolved inorganic nutrients in seawater by scattering yellow loess, a laboratory experiment was conducted for the change of nutrient concentration in seawater during the course of time depending on particle size and scattered concentration of the yellow loess. Twenty four hours after the addition of yellow loess in the size range of 0 $\mu$m to 500 $\mu$m in seawater, the removal rate of dissolved inorganic phosphorus (DIP) was increased with increasing amount of yellow loess. There was little difference among the removal rates depending on the size of yellow loess. On average, $26\%$ of dissolved inorganic silicate was reduced for the same period. No greate difference among the removal rate depending on both size and amount of yellow loess was found. Our results suggested that the removal mechanism of DU seemed to be associated with mostly the chemical bond with iron. More than $99\%$ of initial DU concentration was likely to be removed by this mechanism. In the case of inorganic dissolved silicate, the removal mechanism was likely to be attributed to a cation exchange between the yellow loess and seawater.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.82-92
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• 2007

The purposes of this study were to classify community and to analyzse vegetation-environment relationships in the forest community of Ulleung Island. The forest community of Ulleung Island was classified into Pinus thunbergii community, Pinus densiflora community, Neolitsea sericea community, Pinus parviflora community, and Fagus multinervis - Sorbus commixta community. Since the results of phytosociological community classification were consistent with that of TWINSPAN, it proved that these two methods could complement when one does a community classification. There was a difference in chemical characteristic of soil among study communities. The community had high soil organic matter, total nitrogen, available phosphorous, and cation exchange capacity compared to forest soil of Korea. The soil pH ranged from 4.66 to 5.80. The soil texture in the study communities was loam or sandy loam. According to the ordination analysis, elevation, exchangeable Na, K, Ca, Mg, soil pH, and content of sand and silt affect the distribution of community.

• Journal of the Korea Society for Simulation
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• v.22 no.1
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• pp.9-20
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• 2013

Defense M&S for weapons effectiveness is a realistic way to support virtual warfare similar to real warfare. As the war paradigm becomes platform-centric to network-centric, people try to utilize smartphones as the source of sensor, and command/control data in the simulation-based weapons effectiveness analysis. However, there have been limited researches on integrating smartphones into the weapon simulators, partly due to high modeling cost - modeling cost to accomodate client-server architecture, and re-engineering cost to adapt the simulator on various devices and platforms -, lack of efficient mechanisms to exchange large amount of simulation data, and low-level of security. In this paper, we design and implement Smartphone Adaptor to utilize smartphones for the simulationbased weapons effectiveness analysis. Smartphone Adaptor automatically sends sensor information, GPS and motion data of a client's smartphone to a simulator and receives simulation results from the simulator on the server. Also, we make it possible for data to be transferred safely and quickly through JSON and SEED. Smartphone Adaptor is applied to OpenSIM (Open simulation engine for Interoperable Models) which is an integrated simulation environment for weapons effectiveness analysis, under development of our research team. In this paper, we will show Smartphone Adaptor can be used effectively in constructing a Live simulation, with an example of a chemical simulator.