• 한국분말재료학회지
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• 제9권1호
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• pp.38-42
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• 2002

Effects of chemical compositions on the sintering behavior of the lead borosilicate glass developed for barrier ribs of plasma display panels were investigated in this study. Formation of pores during sintering of the glass was noted and their formation mechanism was investigated using XPS, TG/DTA, and XRD. The results indicated that pores are formed by the oxygen released from Pb-oxides during sintering.

• 환경위생공학
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• 제6권1호
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• pp.95-102
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• 1991

This study was carried out to determine the contamination level of heavy mentals in canned fishes on the market. Contents of tin, lead, iron and zinc were analyzed by Atomic Absorption Spectrophtometer. Contents of total mercury were determined by mercury analyzer. The results were as follows. 1. The highest value of tin was $1.7706{\pm}0.3216$pprn in canned yellow pin & skip jack(mix) tuna, the lowest was 1.2109 ${\pm}$ 0.0769ppm in canned mackerel pike. 2. The highest value of lead was 0.1657 ${\pm}$ 0.0530 pprn in canned yellow pin tuna, the lowest was 0.0335k 0.0100 pprn in canned mackerel pike. 3. The highest value of iron and zinc was 22.5943 ${\pm}$ 0.7945 ppm and 13.4556 ${\pm}$ 0.6774 pprn in canned sardine fish, the lowest was 4.3514 ${\pm}$ 0.3607 pprn and 3.8773 ${\pm}$ 0.1914 pprn in canned albacore tuna. 4. The total mercury contents was detected 0.0531~0.3386 pprn in three kinds of canned tuna and could not be detected with the others.

• 한국분말재료학회지
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• 제21권2호
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• pp.142-146
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• 2014

Fundamental experiences have been studied for development of pre-treatment process of Sn by-products such as solders. Dry and wet separation/recovery processes were considered by the differences of physical properties. The by-products, which are analyzed by solder metal and oxides. The metal and oxide were simply separated by dry ball-milling process for 12 hours, after that recovery metal powder might be reusable as lead or lead-free solders. In terms of wet separation process, samples were dissolved in $HNO_3+H_2O_2$ and the precipitation were analyzed by $SnO_2$. Overall efficiency of recovery might be increasing via developing simple pre-treatment process.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1337-1342
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• 2008

The whisker grows at the plating of a lead frame so that it causes the serious problem like the short. To prove this case, many people have studied the cause and influence of the tin whisker growth. This study explains the grain size affects the growth of the whisker in the lead frame. By these studies about the whisker, the whisker growth is discovered by stresses generated by the intermetallic compound and CTE mismatch in both plating and base metal. The stresses or lattice defect generated in the plating process changes grain structure of plating. Consequently, these various stresses are stabilized by forming unspecified whiskers through lots of grain boundaries. Because the grain boundary is the path of the whisker growth, the smaller grain size exists, the more whiskers grow.

• 자원리싸이클링
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• 제23권3호
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• pp.37-43
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• 2014

폐솔더 박리액으로부터 옥살산 침전법을 이용하여 주석 및 구리의 분리 침전을 통해 각각 금속염으로 회수하기 위한 기초 연구를 실시하였다. 먼저 옥살산의 첨가에 따라 주석의 침전 제거율이 증가하였으며 당량비(옥살산/주석)의 1.0-1.5배를 첨가할 경우 주석이 99.5%의 이상 제거율을 나타내었다. 이 경우에 구리는 2.0% 정도 침전되었고 철, 납등은 침전되지 않아 주석만 선택적으로 침전되는 것을 확인 하였다. 반응온도 증가에 따라 주석의 침전율은 증가하여 $60^{\circ}C$ 부근에서 최대값을 보이다가 온도가 더 증가하면 오히려 감소 경향을 보였다. 침전물을 여과 건조시켜 $SnO_2$의 산화물을 얻을 수 있었다. 주석이 제거된 폐솔더 박리액에 옥살산을 첨가하여 구리를 납, 철 등의 금속이 선택적으로 약 91% 이상 침전되어 회수가 가능하였다.

• 박물관보존과학
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• 제28권
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• pp.89-108
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• 2022

국립중앙박물관 소장 금속활자는 약 50만자로 앞서 연구된 조선 금속활자에 기초해 갑인자(甲寅字)활자 33점, 을해자(乙亥字)병용한글활자 29점 등 조선 전기 금속활자 62점의 형태 조사, 비중을 측정하고 조성성분을 바탕으로 통계분석하였다. 갑인자활자 33점, 을해자병용한글활자 24점은 2성분계 청동(구리-주석)([A]그룹), 을해자병용 한글활자 5점 중 4점은 3성분계 청동(구리-주석-납)([B]그룹) 1점은 2성분계 청동(구리-주석)([C]그룹)으로 주석 함량이 높다. 본 연구에서 다수의 활자 성분 통계분석을 토대로 조선 후기 임진자(壬辰字)활자와 비교한 결과, 후기 활자는 구리 함량이 낮고 아연, 납 함량이 높은 특징이 있어 조선 전기와 후기 활자의 분류 가능성을 확인하였다.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.183-188
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• 1998

Gas sensitizations of tin oxide film were investigated by measuring the change of film resistance in various gas atmospheres such as $N_2,\; O_2,\; H_2O$. The main test sample, polycrystalline $SnO_2$ film containing small Sb as a dopant was prepared by a sputtering technique and showed a long term stability in base resistance and thus, in gas sensitivity. The adsorption of oxygen on the film surface as a type of $(O_{ads})$ at the temperature of around $300^{\circ}C$ played important roles in sensor operating mechanism. The roles were ⅰ) the increase of base resistance in ambient air, which consequently lead to high sensitivity and ⅱ) the promotion of fast recovery. The reaction of hydrogen gas with the already adsorbed $(O_{ads})$ ions was considered as a decisive sensitization mechanism of tin oxide film. However, the dissociation of hydrogen molecules on film surface, by direct donation of electron to film also took a major part in the sensitization. The effect of humidity on gas sensitization was found to be negligible at the sensor operating temperature of around $300^{\circ}C$.

• 한국세라믹학회지
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• 제44권6호
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• pp.313-318
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• 2007

ITO (Indium-tin oxide) thin films have been prepared by a sol-gel spinning coating method and fired and annealed in the temperature range of $450-600^{\circ}C$. The XRD patterns of the films indicated the main peak of (222) plane and showed higher crystallinity with increasing an annealing temperature. The surface of the ITO thin films were treated with 0.1 N HCl 20% solution at room temperature. The effects of surface treatment on electrical properties and surface morphologies of the ITO films were investigated with the results of sheet resistance and FE-SEM, AFM images. The samples, subsequently treated with acidic solution for 40 sec showed the sheet resistance of $0.982\;k{\Omega}/square$. The surface treatment using acidic solution diminished the RMS (root mean square) value and the residual carbon content of the ITO films. It seemed that the acid-cleaning of the ITO thin films lead to the decrease of surface roughness and sheet resistance.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2002년도 춘계학술발표회 초록집
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• pp.43-43
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• 2002

• 대한화학회지
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• 제36권1호
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• pp.161-162
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• 1992