• 대한화학회지
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• 제17권6호
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• pp.411-415
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• 1973

Cyanide ion과 triphenylmethane dye와의 반응은 cetyltrimethyl ammonium bromide(CTABr)의 cationic micelle에 의하여 현저히 반응속도가 빨라지며 sodium lauryl sulfate(NaLS)의 anionic micelle에 의하여 반응속도가 늦어진다. 또한 CTABr존재하의 반응은 inorganic anion에 의하여 inhibition, 되며 NaLS존재하의 반응은 inorganic cation중의 몇가지, 특히 $Zn^{++},\;Cd^{++}$등에 의하여 현저하게 반응이 빨라지는 salt effect를 나타낸다. 물과 잘 혼합되는 몇가지 유기용매의 micelle catalysis에 대한 영향은 대체로 수용액 일때보다 작게 나타나서 반응속도가 늦어지거나 malachite green과의 반응에서 methanol은 수용액일때보다 반응속도가 빨라지는 특이한 solvent effect를 나타내었다.

• Membrane and Water Treatment
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• 제9권2호
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• pp.87-94
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• 2018

The interactions of water soluble polymers with dye are studied by ultrafiltration using a molecular weight cut off of 10 KDa regenerated cellulose ultrafiltration membrane. Two water-soluble polymers, namely Poly (Sodium-4 Styrenesulfonate) (PSS) and Poly (Vinyl Alcohol) (PVA) were selected for this study. The effects of process parameters, such as, polyelectrolyte concentrations, transmembrane pressure, ionic strength and pH of solution on dye retention and permeation flux were examined. PSS enhanced ultrafiltration achieved dye retention as high as 99% as a result of complexation between polyanion containing aromatic groups and cationic dye. This result was confirmed by the red shift. The retention of dye decreases as the salt concentration increases, a high retention was obtained at pH above 4. However, in case of PVA, relatively low retention (50%) was observed. Ionic strength and pH has no significant effect on the removal of MB. The permeate flux depended slightly on polyelectrolytes concentrations, transmembrane pressure, salt concentration and pH.

• Bulletin of the Korean Chemical Society
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• 제16권7호
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• pp.582-588
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• 1995

The preconcentration and determination of trace Cd(Ⅱ), Cu(Ⅱ), Pb(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) in water samples were studied by the precipitate flotation using La(OH)3 as a coprecipitant. The analytes were quantitatively coprecipitated by adding 3.0 mL of 0.1 M La(Ⅲ) solution in a 1,000 mL water sample and adjusting the pH to 9.5 with NaOH solution. After the addition of the 1:8 mixed surfactant solution of each 0.1% sodium oleate and sodium lauryl sulfate, the solution was stirred with a magnetic stirrer for 10 minutes. The precipitates were floated to the surface by bubbling with nitrogen gas and collected in a small sampling bottle. The precipitates were dissolved in nitric acid and then the solutions were diluted to 25.00 mL with a deionized water. The analytes were determined by flame atomic absorption spectrometry. This procedure was applied to the waste water analysis. This technique was simple, convenient and especially rapid for the analysis of a large volume of sample. And also, from the recoveries of better than 92% which were obtained from real samples, this method could be judged to be applicable to the preconcentration and quantitative determination of trace elements in water samples.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.27-32
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• 2002

In this research influences of type and concentration of alkali activator and curing condition on the hydration, and properties of alkali activated blast furnace slag(AAS) concrete were investigated. Sodium carbonate and sulfate were used as alkali activators and their concentration were 4~10 weight percent with Na$_2$O equivalent to binder. The curing conditions were standard curing using 23$^{\circ}C$ water and activated curing chamber at $65^{\circ}C$. Results show that in case of sodium carbonate addition high early strengths were gained by activation of early hydration, but later strength gained was slight. On the other side sodium sulfate strengths were continuously increased with adding amount and ages. Steam curing activated early hydration so that early strengths were improved but later strengths were similar to standard curing. The strength reduction of AAS mortar with sodium sulfate was less than OPC mortar in 5% sulfuric acid solution so that AAS concrete can be useful for acid-resistance concrete.

• 한국세라믹학회지
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• 제27권1호
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• pp.13-22
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• 1990

The magnetite ferrofluids of which solvents are water or kerosene have been prepared by making surfactant absorbed on the surface of the magnetite which have been synthesized by air oxidation of Fe(OH)2 at pH 11 and 75$^{\circ}C$, and their basic properties have been measured by XRD, SEM, DTA, TG, viscometer, magnetometer and B-H tracer. The results are as follows ; 1) The shape of magnetite prepared by air oxidation is found to be sphere-like shape and its particle size is smaller than 200A. 2) The maximum amount of sodium oleate adsorbed on the surface of magnetite is about 20% in the weight of the magnetite including the adsorbed sodium oleate. And when magnetite is well dispersed into solvent, R(the weight ratio of the added sodium oleate to Fe3O4) is 0.40-0.48. 3) The dispersion ratio, the viscosity and the magnetization of magnetite ferrofluid are constant regardless of the added amount of sodium oleate above R=0.40-0.48. 4) The magnetic hysteresis curves of magnetite ferrofluid show superparamagnetism-like behavior.

• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.147-153
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• 1982

The purpose of this study is to observe the effect of cleansing action of irrigation solutions which are 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution on the root canal wall. After the root canal wall is enlarged with K-file in distilled water, the canal wall which is irrigated with each irrigant for 2 minutes, is compared with the. control group without using any irrigants. Each sample is dehydrated, and coated with 200-250${\AA}$ of gold, and observations are made with the use of scanning electron microscope. The results are as follows: 1. The canal walls irrigated with 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution are cleaner than the walls without using irrigants. 2. There are no significant difference of cleansing effect among 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA. 3. After using 3% hydrogen peroxide and 5% sodium hypochlorite solution, large debris are removed on root canal walls, but micro debris remain on the canal walls. 4. The root canal walls irrigated with 15% EDTA solution are decalcifed slightly and show clean surfaces.

• 멤브레인
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• 제6권4호
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• pp.273-283
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• 1996

Polystyrene(PS)과 poly(sodium 4-styrene sulfonate)(PSS)를 이용하여 양이온 교환분리막을 제조하였다. PS 분리막은 divinylbenzene(DVB)의 양에 의하여 가교도를 조절하였으며, 이때 casting 용액 내의 PSS 농도를 변화하여 그 구조를 관찰하였다. PS-DVB RO 분리막이 PSS의 첨가에 의하여 MF 용도로 활용될 수 있음을 보여 주었으며, PSS의 sulfonate group으로 인하여 투과수의 증가를 보여주었다. DVB 5%, PSS 3%의 casting 용액으로부터 최적의 MF 구조를 갖는 분리막이 제조되었다.

• 대한임상독성학회지
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• 제2권1호
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• pp.49-53
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• 2004

A chlorine gas is a common irritant and when exposed, it result in mild occular, oropharyngeal, or respiratory symptoms. In severe case, however, it may result in pulmonary edema, interstitial pneumonia, or respiratory failure. We report the case of 29-year-old and 46-year-old men is accidentally exposed to chlorine gas during cleaning water. The patients complained dyspnea, chest tightness, cough and both eye pain. During hospitalization, they were treated with inhalation of humidified oxygen, beta-adrenergic agonist and $2\%$ sodium bicarbonate. After several days, patients were discharged without respiratory symptoms and complication. In treatment of chlorine gas toxicity the inhalation of sodium bicarbonate is a possible initial therapy can improve respiratory symptoms in spite of lack of evidence.

• 한국식품과학회지
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• 제21권3호
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• pp.364-369
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• 1989

본 실험은 냉동저장 중에 법동변성 방지제의 첨가가 우육과 돈육의 품질에 미치는 영향을 알아본 것으로 냉동변성 방지제 종류는 sorbitol, mono sodium glutamate와 sodium tripolyphosphate를 혼합하여 사용한 CP-A, sorbitol, sucrose와 sodium tripolyphosphate를 섞은 CP-B 그리고 sorbitol, sucrose, sodium citrate와 sodium tripolyphosphate를 사용한 CP-C세 종류이었고 시료는 $-20^{\circ}C$에서 12주간 저장되었으며 분석항목으로는 pH변화, TBA가, 유리지방산 함량의 변화, 수용성 및 염용성 단백질의 추출성이었다. 그 결과를 요약하면 다음과 같다. 1. 냉동변성 방지제 첨가구의 pH는 무첨가구의 pH보다 0.2-0.5unit 정도의 상승효과를 보였으며 TBA가 및 유리지방산 함량은 저장기간이 길어짐에 따라 무첨가구에 비해 증가하는 경향을 보였다. 2. 수용성 단백질의 추출성은 냉동변성 방지제를 처리할 때 돈육이 우육에 비해 높은 추출율을 보였는데 특히 돈육의 CP-B 처리구에서 무첨가구에 비해 우수하였다. 3. 염용성 단백질의 추출성에 대한 냉동변성 방지제의 효과는 우육의 CP-A 처리구와 돈육의 CP-B 처리구에서 무첨가구에 비해 약 10-25%의 높은 추출성 향상을 나타내었다.

• 상하수도학회지
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• 제29권4호
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• pp.481-491
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• 2015

The aim of this study was to evaluate the chemical quenching system for residual ozone and to determine the operating condition for the quenching system. Hydrogen peroxide ($H_2O_2$) and sodium thiosulfate ($Na_2S_2O_3$) were investigated as quenching reagents for ozone removal, and the tendency of each chemical was notably different. In the case of $H_2O_2$, the degradation rate of ozone was increased as the concentration of $H_2O_2$ increase, and temperature and pH value have a significant effect on the degradation rate of ozone. On the other hand, the degradation rate of ozone was not affected by the concentration of $Na_2S_2O_3$, temperature and pH value, due to the high reactivity between the ${S_2O_3}^{2-}$ and ozone. This study evaluates the decomposition mechanism of ozone by $H_2O_2$ and $Na_2S_2O_3$ with consideration for the water quality and reaction time. Furthermore, the removal test for the quenching reagents, which can be remained after reaction with ozone, was conducted by GAC process.