• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2000.04a
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• pp.7-8
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• 2000

• Magazine of RCR
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• v.15 no.2
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• pp.35-38
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• 2020

• Economic and Environmental Geology
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• v.56 no.5
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• pp.619-628
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• 2023

In this study, we investigated the feasibility of calcium sulfate fertilizer as a stabilizing agent for As and Hg contaminated farmland soil and its stabilization characteristics in 3 different physical forms (particulate, powder, and solution) through a pot experiment including 34 days of lettuce growth. As and Hg contents of the lettuce grown in the stabilized soils were decreased by at least 70%. However the lettuce yield of the soil stabilized with the solution agent was decreased by 46% due to the overabundance of the nutrients from the solution agent. Thus, if a solution-type agent is planned for agricultural farmland soil stabilization, additional tests for optimal dosage are needed to preserve vegetation growth. In Hg fractionation, a lower concentration of elemental fractions and a higher concentration of residual/sulfide fractions were identified in the soils stabilized with the solution, powder, and pariculate agents in descending order while there were no significant changes in As fractionation. Overall results suggest that calcium sulfate fertilizer can be used as a stabilizing agent, and a solution-type agent could be used when the operation of heavy machinery for the soil stabilization process is impossible.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.305-314
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• 2010

The stabilization process using limestone ($CaCO_3$) and steel making slag as the immobilization amendments was investigated for As contaminated farmland soils around Chonam abandoned mine, Korea. Batch and continuous column experiments were performed to quantify As-immobilization efficiency in soil and the analyses using XRD and SEM/EDS for secondary minerals precipitated in soil were also conducted to understand the mechanism of Asimmobilization by the amendments. For the batch experiment, with 3% of limestone and steel making slag, leaching concentration of As from the contaminated soil decreased by 62% and 52% respectively, compared to that without the amendment. When the mixed amendment (2% of limestone and 1% of steel making slag) was used, As concentration in the effluent solution decreased by 72%, showing that the mixed of limestone and steel making slag has a great capability to immobilize As in the soil. For the continuous column experiments without the amendment, As concentration from the effluent of the column ranged from 50 to $80\;{\mu}g/L$. However, with 2% limestone and 1% steel making slag, more than 80% diminution of As leaching concentration occurred within 1 year and maintained mostly below $10\;{\mu}g/L$. Results from XRD and SEM/EDS analysis for the secondary minerals created from the reaction of the amendments with $As^{+3}$ (arsenite) investigated that portlandite ($Ca(OH)_2$), calcium-arsenite (Ca-As-O) and calcite ($CaCO_3$) were main secondary minerals and the distinct As peaks in the EDS spectra of the secondary minerals can be observed. These findings suggest that the co-precipitation might be the major mechanisms to immobilize As in the soil medium with limestone and steel making slag.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.349-355
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• 2022

In this study, we sought to identify a soil stabilizer that can be applied to paddy fields vulnerable to arsenic (As) pollution. To this end, we conducted a pot experiment in which we evaluated the effects of different stabilizers on the bioavailability of As in paddy soil. As candidate stabilizers, we assessed calcium superphosphate (CSP), sulfur, and steel slag, which were applied at the rates of 0.7 and 1.4, 0.1 and 0.2, and 7.0 and 14.0 Ma ha^-1, respectively. On day 67 after rice transplantation, we detected significantly lower concentrations of As in the solutions of paddy soil treated with 1.4 Ma ha^-1 CSP (96.9 ㎍ L^-1) and 0.2 Ma ha^-1 sulfur (207.2 ㎍ L^-1) compared with the As concentrations in control (314.5 ㎍ L^-1) and steel slag-treated (268.6-342.4 ㎍ L^-1) soil. Compared with the As concentrations in control brown rice (0.16 mg kg^-1), concentrations in brown rice were lowest in the pots treated with 1.4 Ma ha^-1 CSP (0.09 mg kg^-1). Furthermore, in response to CSP treatments, we detected increases in the weight of rice grains (50.0-50.4 g/pot) compared with the control (40.4 g/pot) and other treatments (26.9-48.1 g/pot), which we speculate could be attributed to the reduction in As toxicity to rice owing to a decline in soil solution As contents and the fertilization effect of the CSP treatment. Collectively, our findings indicate a high-level application of CSP (1.4 Ma ha^-1) to paddy soil has a comparatively beneficial effect in mitigating the bioavailability of As.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.309-309
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• 1994

DA-125에 당류로서 Inositol, Dextrose, Iactose, Mannitol 및 Sorbitol을 첨가하여 DA-125 단독으로 용해한 시료와 비교 평가하였을 때 DA-125의 안정성에 큰 영향이 없었으며, 아미노산 중 L-lysine첨가시 안정성이 향상되는 컷으로 나타났다. 염류를 사용하였을 때는 NaCl, MgSO$_4$첨가시 안정성이 크게 증가하였으며, NaCl의 첨가 농도에 따른 안정성을 시험한 결과 NaCl의 농도 증가에 따라 DA-125의 안정성이 증가하는 것으로 나타났다. 또한 기타 안정화제로 Sodium Bisulfite 첨가시 안정성이 증가되었다. 안정성 시험 중 pH및 용액상태는 변화하지 않았다.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.105-112
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• 2005

Stabilizing and rousing sludge water generated from washing truck mixer and batcher plant can resolve inconsistency in quality and improve strength, therefore it is essential to review how to utilize it. This research conducted experiments and studied on solids of sludge water to find out the types of stabilizing agents available in conditions of producing ready mixed concretes in Korea. The result showed that oxy carboxylic acid retarder dedicated for stabilizing sludge water was most effective in decreasing solid. However, the setting time of cement paste was retarded due to surplus reactants, but it did not impede application of ready mixed concretes. When we left the sludge water mixed with stabilizing agent, it has been noted that initial retard effect recovered to the level using just service water in 7${\~}$8 days and that it is effective to use stabilized sludge water in 2${\~}$3 days. On the other hand, saccharic type super retarding agent was also outstanding in applicability by showing similar effect. The sludge water stabilizing agents currently marketed depend on imports, therefore it is necessary to locally manufacture usable stabilizing agents and to review its usability with multi-dimensional view.

• KOREAN POULTRY JOURNAL
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• v.38 no.3 s.437
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• pp.99-99
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• 2006

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.802-807
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• 2015

In this study, we synthesized a new biocatalyst consisting of glucose oxidase (GOx), polyethyleneimine (PEI) and carbon nanotube (CNT) with addition of terephthalaldehyde (TPA) (TPA/GOx/PEI/CNT) for fabrication of glucose sensor that shows improved sensing ability and stability compared with that using other biocatalysts. Main bonding of the new TPA/GOx/PEI/CNT catalyst is formed by Aldol condensation reaction of functional end groups between GOx/PEI and TPA. Such formed bonding structure promotes oxidation reaction of glucose. Catalytic activity of TPA/GOx/PEI/CNT is evaluated quantitatively by electrochemical measurements. As a result of that, large sensitivity value of $41{\mu}Acm^{-2}mM^{-1}$ is gained. Regarding biosensor stability of TPA/GOx/PEI/CNT catalyst, covalent bonding formed between GOx/PEI and TPA prevents GOx molecules from becoming leaching-out and contributes improvement in biosensor stability. With estimation of the biosensor stability, it is found that the TPA/GOx/PEI/CNT catalyst keeps 94.6% of its initial activity even after three weeks.

• Clean Technology
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• v.12 no.2
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• pp.62-66
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• 2006

Poly($\small{L}$-Lactide)(PLLA) was prepared by a ring-opening polymerization of $\small{L}$-Lactide with various polydimethylsiloxane(PDMS) based copolymers as a stabilizer in supercritical carbon dioxide($scCO_2$). The block copolymeric stabilizers were synthesized by group transfer polymerization (GTP) by using PDMS macroinitiator. PLLA was found to be produced with fairly low molecular weight distribution as confirmed by gel permeation chromatography(GPC) analysis. Scanning electron microscopy (SEM) results showed that sub-micron size Poly($\small{L}$-lactide)(PLLA) particles were formed by suspension polymerization.