http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정의덕,강신원,백우현 한국환경과학회 2000 한국환경과학회지 Vol.9 No.1
A study on the remediation of heavily Fe ion contaminated soils from abandoned iron mine was carried out, using ex-situ extraction process. Also, oxalic acid as a complex agent was evaluated as a function of concentration, reaction time and mixing ratio of washing agent in order to evaluate Fe removability of the soil contaminated from the abandoned iron mine. Oxalic acid showed a better extraction performance than 0.1N-HCI, i.e., the concentrations of Fe ion extracted from the abandoned mine for the former at uncontrolled pH and the latter were 1,750 ppm and 1,079 ppm, respectively. The optimum washing condition of oxalic acid was in the ratio of 1:5 and 1:10 between soil and acid solution during 1 hr reaction. The total concentrations of Fe ion by oxalic acid and EDTA at three repeated extraction, were 4,554 ppm and 864 ppm, respectively. The recovery of Fe ions from washing solution was achieved, forming hydroxide precipitation and metal sulfide under excess of calcium hydroxide and sodium sulfide. In addition, the amounted of sodium sulfide and calcium hydroxide for the optimal recovery of Fe were 15g/ℓ and 5g/ℓ from the oxalic acid complexes, respectively.
정의덕,강신원,박덕수,신학기,백우현 한국환경과학회 2000 한국환경과학회지 Vol.9 No.5
A study on the removal of Pb ion from Pb-contaminated soil was carried out, using ex-situ extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt (IDA) as a washing agent were evaluated as a function of concentration, reaction time, mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1 : 15 and 1 : 20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction, were 368.8 ppm and 267.5 ppm, respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide, form the precipitation of lead hydroxide and lead sulfide, and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/ℓ for the TA washing solution and 4 g/ℓ , 5 g/ℓ for the IDA washing solution, respectively. The efficiency of recycle for TA and IDA washing solution were 78.8%, 95.1% and 89.2%, 96.6%, at third extractions under Na_2S and Ca(OH)_2, respectively.
백우현,정의덕,윤천기 한국환경과학회 2000 한국환경과학회지 Vol.9 No.5
The characteristics of Far-infrared rays mineral water(FIR water) have been compared to the tap water by means of relationship between FIR water and Nuclear Magnetic Resonance spectroscopy(NMR), FIR water and thermography, FIR water and velocity of blood, FIR-water and pH, FIR water and dissolved oxygen(DO), FIR water and Oxidation-Reduction Potential(ORP), using the development FIR water purification of grand prix system. From the experimental result are quite satisfactory when compared with the tap water. Also, the FIR water were evaluated to see if those are tasty and healthy using the Hashimoto's Mineral Balance Index. As a result, FIR-water was found as tasty and healthy.
Jeong, Euh Duck,Borse, Pramod H,Jang, Jum Suk,Lee, Jae Sung,Cho, C R,Bae, J S,Park, S,Jung, O S,Ryu, S M,Won, M S,Kim, Hyun Gyu American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.6
<P>Nanocrystalline CaFe2O4 oxide semiconductor with spinel structure was synthesized by polymerized complex (PC) method and investigated for its physical and optical properties. The crystallization of CaFe2O4 made by PC method was found to occur in the temperature range of 700-1100 degrees C. The observation of highly pure phase and such lower crystallization tempearture in CaFe2O4 made by PC method, is in total contrast to that observed in CaFe2O4 prepared by the conventional solid-state reaction (SSR) method. The activation energy required for the growth of nanocrystalline CaFe2O4 in PC sample was found to be 8.4 kJ/mol. The band gap of nanocrystalline CaFe2O4 determined by UV-DRS was 1.91 eV (647 nm). The photocatalytic activity of PC materials for iso-propyl alcohol photodegradation under visible light (> or =420 nm) was much higher than that of SSR materials.</P>
Thermal stabilities, physical and optical properties of K₂O-Na₂O-Nb₂O5-TeO₂ glasses /
Jeong, Euh Duck,Ha, Myoung Gyu,Pak, Hyuk Kyu,Ryu, Bong Ki,Borse, Pramod H,Lee, Jae Sung,Komatsu, Takayuki,Kim, Hae Jin,Kim, Hyun Gyu The Korean Society of Industrial and Engineering C 2006 Journal of industrial and engineering chemistry Vol.12 No.6
Second harmonic generation and fabrication of transparent K₂O-Na₂O-Nb₂O5-TeO₂ glass-ceramics /
Jeong, Euh Duck,Borse, Pramod H,Lee, Jae Sung,Ha, Myoung Gyu,Pak, Hyuk Kyu,Komatsu, Takayuki,Kim, Hyun Gyu The Korean Society of Industrial and Engineering C 2006 Journal of industrial and engineering chemistry Vol.12 No.5
Jeong, Euh Duck,Kim, Hye Jin,Ahn, Chang Won,Ha, Myoung Gyu,Hong, Tae Eun,Kim, Hyun Gyu,Jin, Jong Sung,Bae, Jong Sung,Hong, K S,Kim, Yang-Soo,Kim, Hae-Jin,Doh, C H,Yang, H S American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.7
<P>Regardless of high capacity and stability during lithium extraction, LiFePO4 materials have difficulty in the applications for high electrical density because of low electrical conductivities. In order to optimize this problem, we synthesized carbon coated LiFePO4 by adding humic acid using solid state reaction method. We characterized the synthesized compounds via the crystallinity, the valence states of Fe ions, and their shapes. We found the carbon coating using X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM). We also found that the iron ion is substituted from 3+ to 2+ through XPS measurement. We showed that the carbon coating increased the electrochemical behavior by measuring the charge-discharge characteristics.</P>
정의덕,원미숙,윤장희,이병호,백우현,Gardella, Joseph A. 한국환경과학회 2001 한국환경과학회지 Vol.10 No.4
For the remediation of the contaminated soil with heavy metals, Cd, Cr, Cu, and Pb, the reaction parameters were optimized. Tartaric acid (TA) and oxalic acid(OA) as a washing agent were evaluated as a function of concentration, reaction time, mixing ratio of washing agent and recovery of metals. The optimum washing conditions of TA and OA were in the ratio of 1 : 20 between soil and acid solution during 2 hr reaction under unbuffered pH solutions. At the optimized reaction conditions, the removal efficiencies were compared with that of 0.1 M HC1 and ethylenediamine tetraacetic acid(EDTA). TA showed higher efficiency on the removal of Pb than that of EDTA, which established for the remediation of contaminated soil with Pb and Cd metals. The recovery of metal ions from washing solution was achieved by adding calcium hydroxide and sodium sulfide by forming the precipitation of metal hydroxide and metal sulfide. Optimum amounts of sodium sulfide and calcium hydroxide were Cd = 25g/ℓ, Cu = 5∼10g/ℓ and Pb = 5∼10g/ℓ for the washing solution of OA and 2∼5g/ℓ for the washing solution of TA, respectively. The amounts of Na_2S and Ca(OH)_2 for the tartaric acid was less than that of oxalic acid.