• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.349-353
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• 2001

There are many excellent characters of Java-based simulation compared with existing ones in the respect of running on the Internet/Web, reuse, integration and etc.. In this paper, the main idea of design and realization of Java-based modeling and simulation software for DEVS will be discussed in detail.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.5-12
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• 1998

Pot experiment was conducted to investigate the effects of fly ash on growth responses and on accumulation of the heavy metals in soil. Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 0.4, 0.8, and 1.2 kg/pot(20L). Tobacco growth was better by application of fly ash than that by the control. However, the early stage of growth by application of bituminous coal, 1.2 kg/pot, was decreased due to the boron toxicity occurred by fly ash. Generally, tobacco yield was significantly increased with applying fly ash, showing the highest yield at 1.2 kg/pot for anthracite and at 0.8 kg/pot for bituminous coal. The content of total nitrogen in leaves was higher with fly ash than that of the control, while the content of calcium in leaves was low, Contents of heavy metal and the other minerals were not significantly different between the control and the treatment of fly ash. Soil pH after experiment was linearly increased with application level of fly ash, indicating that the application of bituminous coal was more effective than that of anthracite. Contents of available phosphate, exchangeable $Ca^{2+}$+ and $Mg^{2+}$ in soil were increased by application of fly ash, especially with bituminous coal. Contents of Cu, Cr, and Ni were increased with application level of bituminous coati even if the contents were still lower than critical levels for farming land. The other heavy metals were similar between the control and the application of fly ash.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.854-856
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• 1997

This paper presents a software development and management technique for open distributed EMS applications. The definite client-server configuration is proposed, and programming languages, software tools, application MMI and database are analyzed to make considerations to determine the development technique. This paper contains specific software management techniques for the development of EMS applications.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.262-270
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• 2014

BACKGROUND: Coal combustion bottom ash(BA) has high carbon and calcium content, and alkaline pH, which might improve nutrient cycling in soil related to microbial enzyme activities as it is used as soil amendment. However, it contains heavy metals such as copper(Cu), manganese (Mn), and zinc(Zn), which could cause heavy metals accumulation in soil. Compost might play a role that stabilize BA. The objective of this study was to evaluate effect of combined application of BA and compost as soil amendment on heavy metals concentration, enzyme activities, chemical properties, and crop yield in upland soil. METHODS AND RESULTS: BA was applied at the rate of 0, 20, 40, and 80 Mg/ha under different rate of compost application (0 and 30 Mg/ha) in radish (Raphanus sativus var) field. Combined application of BA and compost more improved chemical properties such as pH, EC, OM, total nitrogen, available phosphate, and exchangeable cations of soil than single application of BA. Water soluble Mn and Zn concentration in soil significantly decreased with increasing application rate of BA. Decrease in those metals concentration was accelerated with combined application of BA and compost. Urease and dehydrogenase activities significantly increased with increasing application rate of BA. Phosphotase activities were not affected with single application of BA but increased with combined application of BA and compost. Radish yield was not affected by application rate of BA. CONCLUSION: From the above results, combined application of BA and compost could be used as soil amendment to improve chemical properties and enzyme activities of soil without increase in heavy metal concentration and decrease in crop yield in upland soil.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.142-143
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• 2007

A 1MW class HTS(High-Temperature Superconducting) synchronous motor has been developed. This motor is aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field coil of the developed motor is cooled by way of Neon thermosiphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes performance test results of our motor, which was conducted at steady state in generator mode and motor mode.

• Advances in environmental research
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• v.6 no.1
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• pp.15-23
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• 2017

Powdered marble wastes (PMW) generated by Utique marble cutting industries (North of Tunisia) with abundant amounts were used in this study as low-cost materials to investigate the stabilization of heavy metals (Pb, Zn, Fe) in sludge generated from a local Zn-Electroplating factory. Powdered marble wastes were evaluated by means of chemical fractions of heavy metals in sludge and concentrations of heavy metals in leachate from columns to determine their ability to stabilize heavy metals in contaminated sludge. Results indicated that chemical fractions of heavy metals in sludge were affected by application of the PMW mineral materials and pH, however, the effects varied with heavy metals. Application of the powdered marble wastes mineral materials reduced exchangeable metals in the sequence of Pb (60.5%)>Fe (40.5%)>Zn (30.1%). X-ray diffraction and hydro-geochemical transport code PHREEQC analysis were successfully carried out to get a better understanding of the mechanisms of reactive mineral phases involved in reduced exchangeable heavy metals in sludge after PMW material amendments. Therefore, metal immobilization using powdered marble wastes materials is an effective stabilization technique for industrial metallic hydroxide sludge.

• Current Photovoltaic Research
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• v.3 no.4
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• pp.126-129
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• 2015

Over the last two decades, quantum dot (QD) solar cells have attracted much attention due to the unique properties of QDs, including band gap tunability, slow hot electron cooling, and multiple exiton generation effect. However, most of the QDs employed in photovoltaic devices contain toxic heavy-metals such as cadmium or lead, which may limit the commercial application. Therefore, recently, heavy-metal-free QDs such as Cu-In-S or Cu-In-Se have been developed for application in solar cells. Here, we review the research trends in heavy-metal-free QD solar cells, mainly focusing on Cu-In-Se QD-sensitized solar cells (QDSC).

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.41-49
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• 2017

This study was aimed to investigate the influence of cation exchange capacity (CEC) and application amounts of zeolite on the stabilization of heavy metals (As, Ni, Pb, and Zn) in upland soils. The upland soils were sampled from field near mines located in Gyeonggi Province. The CEC of zeolite was treated at three different levels, ie, low, medium, and high, while zeolite was amended with soils at the ratio of 0.1 % and 0.5 % as to soil weight. A sequential extraction was performed for the soil sampled at 1, 2 4, and 8 week after zeolite was added to the soil. The concentrations of Pb and Zn appeared to be high in the sampled soils. The mobility of heavy metals obtained from sequential experiments was as follows: Pb > Zn > Ni >As. Addition of zeolite to contaminated soils effectively reduced exchangeable and carbonate fractions but increased organic and residual fraction, indicating that zeolite is effective for immobilizing heavy metals in soils. The influence of incubation time on the metal stabilization was rather pronounced as compared to the application amount and CEC of zeolite.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.75-80
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• 2016

This study was conducted to evaluate effect of chemical amendments on reducing bioavailable fraction of heavy metals in soil along with ecotoxicological effect on earthworms, Eisenia fetida. Three different chemical amendments, lime (L), steel slag (SS), and acid mine drainage sludge (AMDS), were applied with varied application ratio (1, 3, 5%). Heavy metal contaminated soil was mixed with chemical amedments and earthworms, Eisenia fetida, were cultivated for 28 days. Bioavailable fraction of heavy metals (Cd, Cu, Pb, and Zn) extracted with 0.1N HCl was monitored and also, mortality, growth, and metal concentration in earthworm were assessed. Result showed that all three amendments had high efficiency to reduce bioavailable fraction of heavy metals in soil. In particular, lime showed the highest reduction rate of Cu (63.9-87.7%), Pb (7.90-24.65%), and Zn (40.83-77.60%) among three amendments. No mortality of earthworm was observed during experimental period except 3% and 5% AMDS treatment indicating that application of chemical amendments is safe in terms of ecotoxicological aspect. However, no positive correlation was observed between reduction of bioavaialble fraction of heavy metals in soil and earthworms. Overall, application of chemical amendments in agricultural field can be adapted for reducing bioavailable fraction of heavy metals and detoxification in soil.

• Journal of Applied Biological Chemistry
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• v.42 no.3
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• pp.134-139
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• 1999

The distributions of Cd, Cu, and Zn concentration in soil treated with one (1988) or two (1988 and 1993) applications of sewage sludge at rates of 0, 25, 50, and $100Mg\;ha^{-1}$ (dry weight basis) were determined to assess the accumulation and mobility of the heavy metals. The heavy metals accumulated almost entirely in 0 to 15 cm soil depths. Small amounts of the metals moved out of the tillage zone (0-15 cm depth) into the subsoil, but even at the high rate of sewage sludge, little movement of heavy metals occurred below 100 cm depth. The water-extractable Cd, Cu, and Zn concentrations were very low regardless of the rate of sewage sludge application. Availability of metals as determined by DTPA extraction showed the percentage of DTPA-extractable/total concentration increased with sewage sludge application. In the 0-15 cm depth of sewage sludge treated soil, the percentage of DTPA-extractable/total concentration was higher than 46% for Cd, but the value was less than 27% and 17% for Cu and Zn, respectively. The Cd, Cu, and Zn added to this calcareous clay soil by sewage sludge application were not very mobile, and the amount of plant available form was very small.