• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.65-66
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• 2021

In this study, the optimum amount of hybrid inhibitors i.e. L-Arginine (LA) and sodium phosphate tribasic dodecahydrate (SP), applied for carbon steel rebar in simulated pore concrete (SCP) solution contaminated with 3.5 wt.% NaCl, was discovered. The corrosion inhibition performance of hybrid inhibitors was investigated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. The highest corrosion inhibition efficiency was found as 99.52% corresponding to 2% LA and 0.25% SP after 210 h exposure. Anodic type inhibition action was confirmed by potentiodynamic polarization study. Surface studies including scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to figure out the surface morphology of the steel rebar treated with hybrid inhibitors in order to collaborate with electrochemical studies.

• 한국식품영양과학회지
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• 제25권2호
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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.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.120-125
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• 2016

용매화 된 이온들간의 상호작용은 화학을 비롯한 여러 분야에서 중요하게 다뤄지고 있다. 계산화학에 있어 다양한 용매에 용매화 된 이온들간의 상호작용은 분자동력학 시뮬레이션(MD)을 이용한 PMF 계산을 통해 많이 연구되어 왔는데, 본 그룹에서는 물을 표현할 수 있는 다양한 모델과 Salt solution 하에 Na+ 이온과 Cl- 이온 사이 상호작용을 PMF 계산을 통해 알아보았다. 첫 번째로 Polarizable water model인 Tip4p-fq를 사용한 PMF 계산 결과는 아직 진행 중에 있으며 결과적으로는 기본적으로 CHARMM water force field에서 제공해주는 Tip3p 모델 및 양자계산 방법 중 하나인 Ab initio를 이용한 결과와 비교, 분석 할 예정이다. 두 번째로 1M/2M/5M Salt solution의 서로 다른 농도를 사용하여 시뮬레이션 한 결과 1M과 2M에서는 물 속에서 시뮬레이션 한 결과와 큰 차이가 없었으나 농도가 짙은 5M 용매 내에선 $Na^+$이온과 $Cl^-$이온 사이 거리가 멀어질수록 주변 Salt에 영향을 받는 것을 확인 할 수 있었다. 결론적으로 본 연구를 진행함으로써 우리는 서로 다른 전하를 갖는 이온 사이 상호작용에 대한 이해를 더 높일 수 있었다.

• 한국염색가공학회지
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• 제31권3호
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• pp.177-186
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• 2019

In this study, we investigated for synthetic hydrotalcite in chloroprene rubber foam. Experiments were carried out to find the optimum content ratio by controlling the contents of MgO and Hydrotalcite. Swelling test in toluene immersion was made to measure the crosslinking density of CR foams, and the cure properties were investigated with flat die rheometer and Mooney viscosity. The difference of hardness, tensile strength and elongation at break were observed after immersing in 7% NaCl or 21% NaCl solutions for a day and four days. In addition, the volume change and water content remaining in CR foam were measured after immersing NaCl solution. As content of MgO increased, the value of the cure torque tended to increase, but it was almost constant above 2phr of MgO. However, the Mooney viscosity decreased with increasing MgO content. The crosslinking density, determined by the swelling ratio, showed that the CR compound without MgO showed a higher degree of swelling. When the content of hydrotalcite/MgO was 3:2, it was the lowest volume change of CR form. Also, As the content of hydrotalcite decreased, the difference of mechanical properties before and after immersion NaCl solution increased.

• 한국물환경학회지
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• 제27권2호
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• pp.194-199
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• 2011

This study has been carried out to evaluate the performance of $PbO_2$ electrode for the purpose of degradation of N,N-Dimethyl-4-nitrosoaniline (RNO, indicator of OH radical), generation of ozone and decolorization of Rhodamine B (RhB) in water. The effect of the applied current (0.2~1.2 A), electrolyte type (NaCl, KCl and $Na_2SO_4$), electrolyte concentration (0.0~2.5 g/L) and solution pH (3~11) were evaluated. Experimental results showed that RhB and RNO removal were increased with the increase of current, NaCl dosage and decrease of pH. Ozone generation tendencies appeared with the almost similar to the RhB and RNO degradation, except of solution pH (Ozone generation was increased with increase of pH). Optimum current for RhB degradation and consumption of electric power was 1.0 A. The RhB degradation with Cl type electrolyte were higher than that with the sulfate type. Optimum NaCl dosage for RhB degradation was 1.0 g/L.

• ALGAE
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• 제19권2호
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• pp.123-127
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• 2004

A more rapid and efficient method to extract RNA from Ecklonia cava Kjellman (Laminariales, Phaeophyceae) was introduced in this study. Each step of the procedure was evaluated and the optimal concentration of each chemical in the lysis solution was determined. Tissue pulverization with PVPP and β-mercaptoethanol in the lysis solution were not essential for RNA extraction of this species. The highest yield and purity of E. cava RNA were obtained by the lysis solution containing 1% CTAB, 1 M NaCl, 0.7% PVP, 10mM EDTA and 100mM Tris-Cl (pH 9.0). Approximately 8μg of RNA was obtained from 200 mg of ground tissue. The ratios of the absorbance at 260 nm and 280 nm were from 1.6 to 1.8 and those of at 230 nm and 260 nm were from 1.8 to 2.0. The extracted RNAs obtained in this study turned out to have a sufficient quality for cDNA synthesis.

• 열처리공학회지
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• 제28권3호
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• pp.126-133
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• 2015

The aim of this study is to investigate the effect of solution treatment on the corrosion behavior of Mg-8%Al-(0-1)%Zn casting alloys in 1M NaCl aqueous solution. After the solution treatment, all alloys showed single ${\alpha}$-(Mg) phase microstructure by dissolution of ${\beta}(Mg_{17}Al_{12})$ phase into the ${\alpha}$-(Mg) matrix. The $H_2$ evolution volume decreased with an increase in Zn content, which indicates that the addition of Zn plays a beneficial role in decreasing corrosion rate of the Mg-Al-Zn alloy in solution-treated state. The microstructural evaluations on the corrosion products and corroded surfaces after the immersion test in 1 M NaCl solution revealed that the incorporation of more $Al_2O_3$ and ZnO into the corrosion product, by which the penetration of $Cl^-$ ions is impeded, are thought to be responsible for the better corrosion resistance in relation with the Zn addition.

• 동력기계공학회지
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• 제20권1호
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• pp.42-49
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• 2016

This study showed that on-site ferrate(VI) solution was synthesized by wet oxidation method and applied aqueous 2,4-dichlorophenol(DCP) solution to evaluate the degradation efficiency. On-site ferrate(VI) solution was synthesized by putting $FeCl_3{\cdot}6H_2O$ in the strong alkali solution with NaClO and NaOH and applied DCP solution directly. DCP solution was extracted by the liquid-liquid method and analyzed by GC-ECD. The factors such as pH, DCP initial concentration, injected ferrate(VI) dosage, temperature were investigated. The optimum pH and temperature conditions of DCP degradation were obtained in neutral condition and $35^{\circ}C$. And the experimental results showed that DCP removal efficiency also increased with the decrease of DCP initial condition and the injected ferrate(VI) dosage.

• 한국환경과학회지
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• 제12권10호
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• pp.1131-1136
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• 2003

To examine whether salt stress would alter or not contractility of isolated rat aorta, under anesthesia with sodium pentobarbital(50 mg kg-1 i.p.), male Sprague Dawley rats(300-330 g) were subjected to 0, 50, and 150 mM of sodium chloride at 37$^{\circ}C$ for 60 min. where as the sham group was left at modified Krebs-bicarbonate solution. To measure contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And the strip was checked for expression of heat shock protein(Hsp) by Western blotting. One, three and eight hours later, we measured vascular contractility of isolated rat aorta treated with KCI, phenylephrine from organ bath study. The dose-vascular responses of potassium chloride and phenylephrine showed a little augmentation by NaCl concentration in the strips exposed to NaCl for 8 hours. And the response of relaxation induced by nitroprusside and acetylcholine was not influenced by NaCl stress in isolated aorta ring for 8 hours, respectively. Expression pattern of Hsp 70 of vascular muscle in isolated rat aorta showed a little increase in 150 mM NaCl group at 8 hours after NaCl treatment but not at 3 hours, and Hsp 60 expression of rat aorta was markedly increased in 50 mM NaCl group at 8 hours after NaCl treatment. Taken together, NaCl induced dose-and time dependent accumulation of the Hsp but not affected contraction of rat aorta. These data suggest that short term high salt stress was not sufficient to induce hypertension of rat aorta.

• 대한소아치과학회지
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• 제29권3호
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• pp.469-477
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• 2002

복합레진의 중요한 임상적 단점은 낮은 마모 저항성이며, 이와 관련된 하나의 인자로 수복물의 표면하 분해(subsurface degradation)가 고려되고 있다. 본 연구에서는 알카리성 용액(0.1N NaOH)에 현재 구치부 수복에 많이 이용되는 Z100(3M), Clearfil AP-X(Kuraray), Tetric Ceram(Vivadent)의 3종의 복합레진과 흐름성이 뛰어난 Aeliteflo(Bisco) 등 4종의 광중합형 레진을 보관하였을 때 각 제품의 분해저항성을 평가하고자 하였다. 분해저항성은 다음의 지표를 근거로 평가하였다. 1) 무게손실 - NaOH 용액에 노출 전후의 무게 측정, 2) Si 농도 - 시편을 제거한 용액은 ICF-AE분석기를 통하여 용액내로 용출된 Si 이온 정도 평가, 3) 분해층 깊이 - 용액에 보관한 시편을 연마하여 SEM을 이용하여 분해층의 깊이(${\mu}m$)를 측정하여 다음과 같은 결과를 얻었다. 1. 각 제품의 무게손실량은 Z100, TC, CL, AE 순으로 많았으며, AE, CL군과 TC, Z100군 사이에 유의한 차이가 있었다(p<0.05). 2. 각 제품의 표면하 분해층 깊이는 Z100, TC, CL, AE 순으로 깊었으며, AE. CL군과 Z100군 사이에 유의한 차이가 있었다(p<0.05). 3. 각 제품으로부터 용출된 Si 양은 Z100군이 가장 많고, AE, CL, TC순으로 많았다. 4. 무게손실량과 표면하 분해층 깊이 사이에 비교적 높은 상관관계를 보였다(r=0.71, p<0.05).