• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.481-486
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• 1996

원자력 발전소의 증기 발생기 전열관으로 사용되는 합금 600MA는 미세 구조에 관계없이 가성 용액에서 입계 균열이 발생한다. 본 연구에서는 합금 600 2종과 합금 690 2종의 이음매없는 관 및 진공 용해한 합금 690M 2종의 MA 및 TT재에 대한 부식 조건의 변화에 응력 부식 균열 특성을 일정연신율법(CERT) 및 C-ring법으로 평가하였다. 가성 응력 부식 균열 저항성에 미치는 TT처리의 효과는 용액 조건에 관계없이 TT처리를 행하게 되면 응력 부식 균열에 대한 저항성이 증가하는 것으로 나타났으며, 분극 저항성과는 직접적인 관계가 나타나지 않고 다른 미세 조직 등에 의한 영향을 더 크게 받고 있는 것으로 판단된다. 가성 용액에서의 응력 부식 균열 저항성에 미치는 SO$_4$$^{=}$ 이온의 첨가 효과는 TT처리의 유무에 관계없이 응력 부식 균열 저항성을 크게 감소시키고 있다. 한편 합금 690의 가성 응력부식 균열 저항성에 미치는 Mo의 효과는 Mo이 첨가될수록 응력 부식 균열 저항성이 증가하는 것으로 나타났다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.2
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• pp.346-351
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• 1996

본 연구는 고등학교 1학년 여학생 25명을 대상으로 한달간 평소 염분에 대한 염미도(염분 섭취력)를 측정하여 동일한 농도의 염분용액일지라도 염분용액의 내용물에 따라 염미도에 차이를 나타내는 지의 여부를 확인하고자 1개월간 염분 섭취력을 측정하여 저염 선호 섭취력군, 정상 선호 섭취력군, 고염 선호 섭취력군으로 나누어 과거의 염분 섭취력이 짠맛 기호에 변화를 초래할 수 있는지를 조사한 것이다. 동일한 농도의 염분용액일지라도 염분용액의 내용물을 달리하는 방법으로 0.9% 동일한 농도의 순수 염분액, 1%초산과 3% 백설탕을 혼합한 혼합 염분액, 간장으로 간을 맞춘미역국, 된장으로 간을 맞춘 시금치국, 소금으로 간을 맞춘 콩나물국 등의 5종을 만들고 실험 대상자에게는 평상상태, 24시간 금식, 저단백 식사, 고단백 식사 등의 4종의 상태로 조건을 준 후 상기에서 준비된 실험용액을 맛보게 한 후 최적 염분 염미도를 짜다, 적당하다, 싱겁다로 평가하도록 하였다. 결과는 다음과 같다. (1)식염 섭취량은 고염 섭취력군에서 가장 높았으며, 한국인의 평균 섭취량 보다 높았으며, 한국인의 평균 섭취량 보다 높았다. (2)과거의 염분 섭취력이 신체조건의 변화와 용액의 종류에 따라 염분 기호에 영향을 미쳤으며 특히 간장미역국, 된장시금치국, 소금콩나물국 같은 조미된 음식을 선호하였다. (3)식염 배설량은 1일전의 섭취력과 무관하게 거의 일정하게 배설되었다.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.157-162
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• 2009

In this paper, the density, viscosity and solubility are measured to know the physical properties of dye. By changing the concentration of dye solution, the density change of the dye solution was very small and the viscosity of the dye solution was increased. Also, by changing the temperature of dye solution, the density change of the dye solution was increased but the viscosity of the dye solution was decreased. Solubility of dye conducts under the changing the salt and concentration of dye. In 20 wt% of dye and 15 wt% KCl, the amount of dye crystal is maximal. Also, batch salting-out experiments were performed with various conditions to know the optimal operating conditions of dye crystal. Under the various experiments, optimal operating condition was found based on amount of dye; added 15 wt% KCl, $25^{\circ}C$ temperature, 100 RPM, added at once.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.735-740
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• 2002

In order to improve the anti-fogging property of polymer films, organic-inorganic hybrid coating solutions which have good hydrophilic property and transmission in the range of visible light were synthesized by the sol-gel method. The coating solutions were prepared by adding glycidoxypropyl trimethoxysilane(GPS) to a colloidal silica(15 nm) suspension(Ludox). GPS as silane coupling agent forms strong bonds to the colloidal silica and surrounding polymer matrix and links two different materials together. Solutions prepared by addition of GPS at the acidic condition resulted in coatings that were less prone to cracking, while those at the basic condition caused coatings with more cracking. These resulted in better hydrophilic property and transmission in the range of visible light for the solution prepared at the acidic condition(pH 2). Compared with coatings under acidic conditions, coatings prepared at basic conditions showed worse hydrophilic property and transmission in the range of visible light.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.95-97
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• 2003

본 연구에서는 새도우마스크 제조공정에서 발생되는 Fe-Ni 계 폐산 용액에 Ni 성분을 용해시킨 복합 산용액을 원료용액으로 사용하여 분무열분해법에 의해 입도분포 및 조성이 균일하며, 입자형태가 구상이면서 평균입도가 100nm 이하인 Ni-ferrite 나노 분말을 제조하며 원료용액의 유입속도, nozzle tip 크기 및 공기압력의 반응조건 변화에 따른 생성분말의 특성 변화를 파악하였다.

• Resources Recycling
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• v.32 no.3
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• pp.38-44
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• 2023

Leaching tests were conducted using sulfuric acid and sodium hydroxide solutions to remove impurities from domestic graphite concentrate. As a result of the leaching experiment using sulfuric acid solution and sodium hydroxide solution, respectively, the difference of removal efficiency was insignificant when the concentration of sodium hydroxide or sulfuric acid was 2 mol/L or more. The fixed carbon content increased with increasing the temperature in the sulfuric acid solution leaching, while it remains constant above 150℃ in sodium hydroxide solution. For the repeated sequential leaching tests, the leaching conditions were 2 mol/L NaOH, 200℃, 1 hour in the sodium hydroxide solution leaching and 2 mol/L H₂SO₄, 100℃, 1 hour in the sulfuric acid solution leaching, respectively. When sulfuric acid leaching followed by sodium hydroxide solution leaching was repeated 5 times, the fixed carbon increased to 99.95% and ash content decreased to 0.048%, while the fixed carbon increased to 99.98% and ash content was reduced to 0.018 when sodium hydroxide solution leaching followed by sulfuric acid solution leaching was repeated 5 times.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.278-283
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• 2005

Cement and paraffin waste form were prepared with a acid extraction method for the analysis of radionuclides generated from nuclear power plants. The acid extraction method was carried out with $HNO_3-HCl$ acid. At first, we compared the method with the microwave acid digestion method using SRM. The solutions of decomposed SRM were then analyzed by AAS and ICP-AES. The acid extraction method had shown good results as microwave acid digestion method. This method provided recovery values greater than $80\%$ for metallic elements.

• Food Industry And Nutrition
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• v.8 no.2
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• pp.51-55
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• 2003

송이 향을 오랫동안 유지하기 위한 기초자료를 얻을 목적으로 일반적으로 많이 이용되는 감자전분을 matrix로 사용하여 송이 향의 주성분인 1-octen-3-ol을 미세캡슐화 하는 조건을 조사한 결과는 다음과 같다. 전분농도5.5% 이하 용액의 점도는 $60^{\circ}C$에서 420 cP이하를 나타내었고 6.0% 이상의 용액은 820cP 이상을 나타내어 이 농도를 경계하여 점도의 변화가 뚜렷하게 구별되었다. 균질화하기 전과 후의 감자전분용액의 점도변화에서는 감자전분에 emulsifier와 1-octen-3ol을 첨가하여 균질화한 에멀젼 용액의 점도가 균질화하기 전 용액의 점도보다1/2 이하 값을 나타내어 균질화 공정이 용액의 점도를 낮추었다. 감자전분용액의 농도가 높을수록 1-octen-3-ol의 잔존량이 많았다.

• Resources Recycling
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• v.17 no.6
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• pp.17-23
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• 2008

In order to simulate the leaching solution of copper sulfide ore in $FeCl_3$ solutions, synthetic solutions with composition of $FeCl_3$-$FeCl_2$-$CuCl_2$-CuCl-NaCl-HCl-$H_2O$ were prepared. The concentration of iron and copper chloride was varied from 0.1 to 1 m in synthetic solutions. The effect of composition on the mixed solution pH and potential at $25^{\circ}C$ was measured. When HCl concentration was constant, the increase of CuCl concentration increased solution pH. The increase of other solutes excluding HCl and CuCl decreased solution pH owing to the increase of the activity coefficient of hydrogen ion. A high CuCl concentration favored the redox equilibrium in the direction of Cu(I), while $FeCl_3$ had the opposite effect.

• Resources Recycling
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• v.17 no.5
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• pp.37-43
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• 2008

Stripping experiments of iron from the loaded Alamine336 by sulfurous, chloric and sulfuric acid solutions have been performed by varying the concentration of acid and stripping conditions. The stripping percentage of iron decreased with the increase of HCl and $H_{2}SO_4$ concentration, while that increased with the increase of $H_{2}SO_3$ concentration up to 3 M. Stripping temperature had adverse effect on the stripping percentage of iron in the stripping by $H_{2}SO_3$ solution, while the stripping percentage of iron by HCl solution increased with the increase of temperature. Stripping isotherm of iron by 0.1 M HCl and 0.1 M $H_{2}SO_4$ solution indicated that three and four stripping stages could result in a solution containing 0.05 M iron at an O/A ratio of 1/10 from the loaded Alamine336 phase where iron concentration was 0.5 M.