• 한국염색가공학회지
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• 제11권4호
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• pp.50-56
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• 1999

The adhesive properties of polyester cord in rubber matrix were investigated according to the surface modification. The polyester cord was oxidized in sodium hypochlorite solution, and graft-polymerized with acrylic acid under the irradiation with ultraviolet light, and then coated with resorcinol-formaldehyde latex (RFL). The modified surface was checked with scanning electron microscope. The adhesive properties were measured by the full-Out method, and evaluated with regard to the energy of adhesion and the maximum load. The polyester was not oxidized in sodium hypochlorite solution, so the surface was not able to etch to produce the coarse topology. As the concentration of acrylic acid and the reaction time were increased, the graft yields were also increased. It was considered that the acrylic acid would swell the polyester and diffuse easily to the inner side of substrate. The adhesive properties of polyeser to rubber matrix were affected by the surface condition. Namely, the maximum load was almost same, but the energy of adhesion was rather higher In the polyester grafted with acrylic acid than in control one. We concluded that the flexible aliphatic chains of polyacrylic acid situated in the interface of cord and rubber matrix were distributed well the stress and strain all over the filler resulting the high energy of adhesion.

• Corrosion Science and Technology
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• 제3권6호
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• pp.227-232
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• 2004

The carboxylates as a corrosion inhibitor has been studied by many researchers because of its environmental safety and low depletion rate. However, conventional test methods of inhibitor such as weight loss measurements, linear polarization resistance and corrosion potential monitoring etc., evaluate uniform corrosion of metals. These methods are unable to evaluate crevice-related corrosions, which are encountered in most of heat exchanging facilities. In order to choose the optimum corrosion inhibitor, the appropriate test methods are required to evaluate their performances in service environment. From this point of view, polarization technique was used to evaluate the characteristics of sodium heptanoate on corrosion behavior for carbon steel. Especially a thin film crevice sensor technique were applied to simulate the crevice corrosion in this study. From these experiments, we found that oxygen as an oxidizing agent was required to obtain stable passive film on the metal. Presence of oxygen, however, accelerated crevice corrosion. Potential shift by oxygen depletion and weakened inhibitive film inside the crevice were responsible for such accelerated feature. It is shown that film for corrosion inhibition is a mixture of sodium heptanoate and iron (II) heptanoate as reaction product of iron surface and sodium heptanoate. The iron (II) heptanoate which has been synthesized by reaction of heptanoic acid and ferrous chloride in methanol solution forms bidentate complex.

• 자원리싸이클링
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• 제26권2호
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• pp.39-45
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• 2017

양극흙에서 금의 불균일 분포에 따른 영향을 배제하기 위해 금과 은 금속혼합물을 사용하여 염산과 산화제(질산, 과산화수소, 차아염소산나트륨)의 혼합용액, thiourea 및 thiosulfate에 의한 침출실험을 수행했다. 염산에 산화제로 질산이나 과산화수소를 첨가한 용액에서 금은 모두 용해되었으나, 은의 침출율은 1% 정도이었다. Thiourea와 thiosulfate용액에서 금은 전혀 용해되지 않았다. 산성의 thiourea용액에 제 2철이온을 첨가하면 은의 침출율이 상승했으며 제 2철이온과 황산의 복합효과를 규명하기 위해서는 추가 연구가 필요하다.

• 한국환경과학회지
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• 제25권11호
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• pp.1541-1554
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• 2016

To understand the characteristics of vanadium leaching from soils formed by the weathering of basalts, paleo soil at Gosan, Jeju Island, Korea, and several present-day soils from neighboring areas were collected. Leaching experiments were carried out by two approaches: 1) batch experiments under various geochemical conditions (redox potential (Eh) and pH) and 2) continuous leaching experiments under conditions similar to those of natural environments. From the batch experiments, leached vanadium concentrations were highest under alkaline (NaOH) conditions, with a maximum value of $2,870{\mu}g/L$, and were meaningful (maximum value, $114{\mu}g/L$) under oxidizing ($H_2O_2$) conditions, whereas concentrations under other conditions (acidic-HCl, $neutral-NaHCO_3$, and $reducing-Na_2S_2O_3$) were negligible. This indicated that the geochemical conditions, in which soil-water reactions occurred to form groundwater with high vanadium concentrations, were under alkaline-oxidizing conditions. From the continuous leaching experiments, the pH and leached vanadium concentrations of the solution were in the ranges of 5.45~5.58 and $6{\sim}9{\mu}g/L$, respectively, under $CO_2$ supersaturation conditions for the first 15 days, whereas values under $O_2$ aeration conditions after the next 15 days increased to 8.48~8.62 and $9.7{\sim}12.2{\mu}g/L$, respectively. Vanadium concentrations from the latter continuous leaching experiments were similar to the average concentration of groundwater in Jeju Island ($11.2{\mu}g/L$). Furthermore leached vanadium concentrations in continuous leaching experiments were highly correlated with pH and Al, Cr, Fe, Mn and Zn concentrations. The results of this study showed that 1) alkaline-oxidizing conditions of water-rock (soil) interactions were essential to form vanadium-rich groundwater and 2) volcanic soils can be a potential source of vanadium in Jeju Island groundwater.

• 한국식품저장유통학회지
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• 제9권2호
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• pp.154-160
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• 2002

박피 토란의 저장성을 향상시키기 위한 방안으로 전해산화수, 유자과즙을 첨가한 전해산화수 및 명반수를 사용하여 제조한 침지저장액에 따른 저장 효과를 살펴본 결과, 토란 수분함량은 80.05%에서 저장 25일째 수분의 흡수로 인해 82.12~84.24%로 다소 증가하였으나 처리구간의 차이는 거의 없었다. 색도는 전반적으로 L값은 감소하였으며 a, b값이 증가되는 현상을 보여주었으며, 조직감은 모든 처리구에서 초기 4,520$\pm$75 g에서 점차로 감소하는 경향을 보였으나 그 감소 폭이 유자과즙첨가구가 가장 적은 것으로 나타나 저장 25일째 4,160$\pm$80 g의 수준을 보였다. 총 vitamin C함량은 0.5%유자과즙 첨가 구에서 25일째 6.99 mg%로 약 57%의 보존율을 보여 가장 손실이 적었다. 총당은 대부분의 처리구에서 저장 15일째까지 급격히 하강하다가 저장 15일 이후에는 감소속도가 완만한 것을 볼 수 있었으며, 저장 중의 유리당의 함량은 저장기간에 따른 증감의 큰 변화 폭은 관찰할 수 없었다. 단지 sucrose 함량은 저장 중반기인 10일 전후에 일부 감소하다가 다시 증가하여 저장 25일째에는 처리구에 관계없이 저장 초기 값의 1.5~2배 수준에 도달하였으며, fructose, glucose, maltose는 저장기간별 처리구간에 따른 유의적인 차이가 나타나지 않았다. 박피 토란의 주 아미노산은 aspartic acid와glutamic acid로 각각 1,084.8 mg/100g. 691.8 mg/100g으로 나타났으며, 전해산화수에 침지하여 저장한 경우 aspartic acid 함량이 초기보다 13.9% 수준 증가하였다. 한편, 필수아미노산총량은 유자과즙 첨가구에 저장한 경우가 총당 감소율 측면에서 가장 유리한 것으로 나타났다.

• 대한화학회지
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• 제29권2호
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• pp.158-163
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• 1985

2M $AgNO_3$ 수용액을 백금이나 탄소 전극을 이용하여 비교적 높은 전류밀도에서 전해 산화하였다. 이 생성물을 산화력과 X-ray powder diffraction patterns, thermal analysis, 그리고 환원 곡선등을 구하여 $Ag_7O_8NO_3$ 임을 확인하고 끓는물에서 가수분해 하여 Alfa-product AgO보다 순도가 높고 비중이 큰 AgO를 얻을 수 있었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.51-54
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• 2001

This research was carried out to evaluate feasibility of using an Electrokinetic-Fenton(EK-Fenton) technique to treat hydrophobic organic pollutant(phenanthrene) from soils. Experiment examined the effect by introducing a continuous flow of a 3.5% hydrogen peroxide solution at the anode. An electric gradient of 1V/cm was applied to enhance the saturated flow in the soil cell for a period of 11 days. After 11 days or 1 pore volume, overall concentration of residual phenanthrene in the soil cell was 11% and residual phenanathrene concentration in the soil was found to increase with toward the cathode. This results indicated that Fenton-like reaction catalyzed by mineral surface was effective in oxidizing phenanthrene. This results also showed that hydrogen peroxide was effectively transported into the soil by electroosmotic flow as well as by diffusion.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.108-109
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• 2002

Electrolyzed chlorous solutions, or electrolyzed oxidizing water [EW(+)] has attracted much recent attention as a low cost, but high-performance, new technology of potential use by food industry. the term EW(+) is used to describe an aqueous disinfectant produced by the electrolysis of a chlorine containing solution under a low-voltage direct current (Suzuki et al., 2002). (omitted)

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.201-201
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• 2011

Recently, mussel-inspired surface modification, called polydopamine coating has been extensively implemented to many areas, due to its material versatility and ease to use. In particular, incubation of substrates in an alkaline dopamine solution resulted in self-polymerization of dopamine and modified variety of material surfaces, including noble metals, metal oxides, ceramics, and synthetic polymers. However, the polydopamine coating has a drawback to practical use; it takes more than 12 hrs to introduce sufficient polydopamine layers to solid substrates. Here, we investigated the rate-enhanced polydopamine coating by varying reaction conditions: pH, concentration, and the addition of the oxidizing agent. As a result, the optimum condition for fast polydopamine coating was found, and solid substrates were efficiently coated with polydopamine layers in just few minutes using the condition. The polydopamine-modified surface was characterized by XPS and contact angle goniometry, and the biocompatibility of the modified surface was also proved by cell attachment test.

• 자원리싸이클링
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• 제26권1호
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• pp.30-36
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• 2017

양극흙에 함유된 금과 은을 회수하기 위해 무기산(염산, 질산, 황산)과 thiourea 및 thiosulfate에 의한 침출실험을 수행했다. 산화제를 첨가하지 않은 조건에서 금은 무기산용액에 전혀 용해되지 않았다. 3종류의 무기산의 농도가 동일한 조건에서 황산용액에서 은의 침출율이 가장 높았으며, 염산의 농도가 증가함에 따라 $AgCl_2{^-}$의 형성에 따라 은의 침출율이 증가하였다. 한편 주석은 질산용액에 전혀 용해되지 않았으나, 구리, 니켈과 아연은 본 실험조건에서 모두 용해되었다. 황산과 thiourea의 혼합용액에서 금과 은은 모두 용해되었다. Thiosulfate용액에 은의 일부가 용해되었으나, 금은 전혀 용해되지 않았다.