• 한국응용과학기술학회지
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• 제37권5호
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• pp.1222-1228
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• 2020

Tin bis(monohydrogen orthophosphate) monohydrate 물질의 흡착 성질에 관하여 KCl 수용액을 통하여 조사하였다. 금속이온 농도와 pH를 변화시키면서 어떻게 달라지는지 화학평형에 바탕을 두고 data를 분석하였다. 금속이온들의 흡착 data는 Langmuir 흡착식에 넣어 Langmuir 수치들을 얻는 데 사용되었다. Tin phosphate는 산성에서 이온교환 화합물로 작용하였으며, 2가의 전이금속이온에 대해 Cu⁺² > Co⁺² > Ni⁺²의 순서로 선택적 흡착성질을 나타내었다. 약한 산성 이온 교환체에서와 같이 금속이온의 교환은 tin phosphate의 선택성을 결정하는데 결정적 역할을 하였다. 모든 경우에서 흡착의 정도는 온도와 농도의 증가와 함께 증가하였다. Lnngmuir 수치들은 흡착과정 동안의 엔트로피, 엔탈피, 자유에너지 변화량같은 열역학적 함수들을 계산하는데 이용되었다.

• 자원리싸이클링
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• 제25권4호
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• pp.42-48
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• 2016

주석도금폐액으로부터 고순도 주석 금속을 회수하는 연구를 실시하였다. 먼저 주석도금폐액을 Iminodiacetic 관능기를 가진 이온교환수지(Lewatit TP 207)를 사용하여 1차적으로 유기물 및 Fe, Zn, Na 등의 불순물을 제거하였고, 2차적으로 Ethylhexyl-phosphate의 관능기를 가진 이온교환수지(Lewatit VPOC 1026)를 사용하여 잔류하고 있는 불순물들을 모두 제거하여 고순도의 주석용액으로 회수하였다. 회수된 주석용액으로부터 고순도 금속주석으로 회수하기 위하여 사이클론식 전해방법을 사용하였으며, 전해채취 결과 약 99.98% 순도의 주석을 회수할 수 있었다.

• 자원리싸이클링
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• 제24권3호
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• pp.51-58
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• 2015

주석도금폐액으로부터 이온교환수지를 사용하여 주석 회수에 대한 연구를 실시하였다. 3종류의 이온교환수지를 사용하여 기초 실험한 결과 tertiary 기능기를 가진 이온교환수지(Lewatit TP 272)는 주석을 흡착하지 못하였고, iminodiacetic기능기를 가진 이온교환수지(Lewatit TP 207)는 주석의 흡착율은 높으나, 회수된 주석용액 내 불순물 함량이 높았다. Ethylhexyl-phosphate의 기능기를 가진 이온교환수지(Lewatit VP OC1026)를 사용한 경우, 주석의 흡착율이 iminodiacetic기능기를 가진 이온교환수지 보다 낮았으나 pH 조절에 따라 회수된 주석용액 내 불순물의 제거가 가능하였다. 또한 이온교환수지에 흡착된 유기물의 경우는 수세를 통해 제거를 함으로써 고순도 주석용액으로 회수가 가능하였다.

• Bulletin of the Korean Chemical Society
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• 제28권7호
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• pp.1171-1174
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• 2007

We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/ mL).

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.965-968
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• 2009

• 자원리싸이클링
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• 제19권3호
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• pp.45-51
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• 2010

염산용액으로부터 TBP(Tri-butyl Phosphate)를 사용하여 주석(IV)의 추출에 대한 기초연구를 실시하였다. 수용액상에서 염산과 염소이온($Cl^-$) 농도, 주석 농도 및 추출제 농도 등과 같은 실험인자들이 주석의 추출에 미치는 영향을 조사하였다. 염산과 염소이온 농도가 증가할수록 주석의 추출율이 증가하였고, 7.0M의 염산농도에서 10% TBP에 의해 주석이 98%이상 추출되었다. McCabe-thiele 도표 분석을 통해 주석의 연속 추출에 필요한 이론적인 최적 추출단수를 구하였다. 한편 탈거액으로 NaOH 용액이 효과적이었고, 2.0M NaOH 에서 99.3%이상의 높은 탈거율을 나타냈다.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.127-131
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• 2006

Radiosynovectomy has been used as an effective treatment in patients with resistant synovitis after failure of long-term medication and intraarticular steroid injection. Although $^{90}Y$ silicate/citrate, $^{186}Re$ sulfide, and $^{169}Er$ citrate were approved in Europe for the appropriate radiopharmaceuticals for radiosynovectomy other radionuclides such as $^{32}P$-chromic phosphate, $^{165}Dy$-ferric hydroxide macroaggregate, $^{188}Rh$-microspheres, $^{153}Sm-particulate, and $^{166}Ho$-ferric hydroxide macroaggregate have been used in many countries. Reported success rates range from 40% to 90% for the different joints and underlying disease. In Korea, $^{188}Re$-tin-colloid and $^{166}Ho$-chitosan complex are now using as the major radionuclides in radiosynovectomy with good clinical results. A study on radiation synovectomy using $^{188}Re$-tin-colloid for patients with Korean rheumatoid arthritis shows the treatment resulted in the improvement of arthritis and well tolerated in our study, the radiosynovectomy with $^{166}Ho$-chitosan complex in 53 hemophilic patients markedly decreased intra-articular bleeding frequency and need for coagulation factor. This review inculdes general priciples in the application of radiosynovectomy and the clinical experience in Korea.

• Bulletin of the Korean Chemical Society
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• 제21권7호
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• pp.709-711
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• 2000

Oxidizing metal complex mediates the electrochemical oxidation of guanine nucleotides. This catalysis results in an enhancement in cyclic voltammograms that yield the rate constant for the oxidation of guanine by the metal complex via digital simulation. The rate constant of oxidation of guanine by Ru(bpy)3(3+) is 6.4 x 10(5)M(-1)s(-l). The rate constant and the enhanced current depend on the number of phosphate groups on the sugar of nucleotidc. Also the modified guanine bases show different oxidation rate constants following the trend guanine-5'- monophosphatc (GMP) > 8-bromo-guanine-5'-monophosphate (8-Br-GMP) > xanthosine -5'-monophosphate (XMP) > inosinc-5'-monophosphate (IMP). The guanine bases derivatized differently are all distinguishable from one another, providing a basis for studying electrochemistry of DNA and RNA and developing electrochemical biosensors.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.64-72
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• 1994

Zinc Phosphate Cement hand been used for about more than 100 years in luting of cast gold inlay. But many scientists had been trying to develop the new form of luting agent because the ZPC hand shown the lack of adhesiveness on the tooth structure and the toxicity to the pulp tissue. Recently many researches about the surface treatment of the cast body are being done to increase the adhesion of cement to it. The conventional Class I gold inlays were fabricated in the 20 permanent molars. After the internal surface of the cast body was sandblasted with $Al_2O_3$ particles and was tin-plated, the inlays were cemented with adhesive cement [G I cement and resin cement(Super-Bond & $Panavia_{EX}$)] and the evaluation on the adhesion pattern, adhesive strength and the fracture pattern of the adhesive cast gold inlay was compared to that of the cast gold inlay cemented conventionally with ZPC. The results were as follows : 1. The surface roughness of the cast body was increased significantly after sandblasting with the $Al_2O_3$ particles and the tin oxide layer, which was consisted of round particles, came into being. 2. The bond strength was in the order of Super-Bond, ZPC, Fuji I, $Panavia_{EX}$ group. The group cemented with Super-Bond showed statistically greater strength than the other groups(p<0.05). 3. The group cemented with ZPC was fallen apart by principal adhesion failure and that with Fuji I was by complete adhesion failure. But the group with Super-Bond showed pricncipal cohesive failure pattern and in the group with $Panavia_{EX}$, complete cohesive fracture pattern was shown and small protion of tooth structure was fractured out with cast body and the fractured surface showed the figure just as the enamel prism. 4. Various gaps were shown at the pulpal side regardless of little gap at the side walls of the cavity in all groups. Only the Super-Bond was attached to the tooth structure and the other cements were detached from both the tooth and the cast body.

• 보존과학회지
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• 제36권1호
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• pp.47-59
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• 2020

Scientific analysis was conducted to identify the paint pigments used in the Buseoksa Josadang murals. optical microscopy(OM), X-ray fluorescence(XRF), XRF mapping, scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS), and Raman spectroscopy were performed to examine the pigments. The results confirmed that the Josadang murals consist of two paint layers wherein the pigments were distinct for most colors. It was estimated that celadonite, white clay, red ochre, cinnabar and minium, synthetic green pigment containing tin and zinc paratacamite, or botallackite were used in the upper layer. In addition, bone white, celadonite, red ochre, azurite, cinnabar or vermilion, and gold were identified in the lower layer. In addition, as Zn and Sn were detected in the green pigments extracted from the top layer of the paint, it is believed that Josadang murals were repainted over the original paint layer at some point after the 17th century. In addition, white pigments containing calcium phosphate were found in all the colors in the bottom layer, which is the original paint layer. These results are significant because this is the first time that white pigments are found in Korean traditional paintings. Additionally, the information revealed about the pigments in this study will serve as areference for the pigments used in the Goryeo period.