• Journal of the Korean institute of surface engineering
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• v.4 no.1
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• pp.16-23
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• 1971

In this study , fluoborte solution consisting of lead fluoborate, tin fluoborate and cupric acetate was used. By addition of small amount of Cu+= ion to the solution, the Cu content of deposition layer was almost controlled less than 5%. The amount of Cu in deposition layer was almost constant without any influence of Pb++ & Sn++ in the solution, and the amount of Pb was increased by the increase of total concentration of Pb++ +Sn++ in the solution, and the amount of Pb was increased by the increase of total concentration of Pb++ +Sn++ in the solution . Agitation of plating solution & low current density result in the increase of Cu content. Analyzing of microscopic structures and etching tests of the deposited alloy, it was believed that the alloy had a lamellar structure consisting of copper rich lamellar and lead rich layer.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.75-76
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• 2006

New PM route via bulk mechanical alloying is developed to fabricate the solid solution semi-conductive materials with $Mg_2Si_{1-x}Ge_x$ and $Mg_2Si_{1-y}Sn_y$ for 0 < x, y < 1 and to investigate their thermoelectric materials. Since $Mg_2Si$ is n-type and both $Mg_2Ge$ and $Mg_2Sn$ are p-type, pn-transition takes place at the specified range of germanium content, x, and tin content, y. Through optimization of chemical composition, solid-solution type thermoelectric semi-conductive materials are designed both for n-and p-type materials.

• Journal of Conservation Science
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• v.22
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• pp.87-98
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• 2008

Microstructures and chemical compositions of 24 bronze mirrors recovered from the Korean peninsula were examined using the scanning electron microscope equipped with the energy dispersive spectrometer in an effort to characterize the treatments applied on their surface. Their provenance and chronology are mostly unspecified except for two objects from a Koryo burial site. In antiquity the surface of bronze mirrors was frequently finished by mere polishing when their tin content was high enough to guarantee the required reflectivity. In many cases, however, their surface was given a special treatment. The most typical treatment was to coat the surface with tin in two different processes referred to as wipe-tinning and amalgam-tinning. In wipe-tinning only tin was used, but in amalgam-tinning tin and mercury were used together. The surface was often coated with mercury in a process known as mercury-polishing. The present mirrors showed that all these techniques were in fact practiced, not only on the reflective surface but, in some cases, on the decorative surface. The detection of mercury played a crucial role in the assessment of a specific technique applied in each mirror. Mercury often remained in the substrate in the form of sulfide and thereby allowed the method of surface treatment to be estimated even when the coated layer was completely lost. The future study is expected to uncover the regional and temporal variation of the surface treatments to the better understanding of bronze mirrors with respect to provenance and chronology.

• Journal of Conservation Science
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• v.30 no.4
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• pp.345-351
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• 2014

Chemical and Pb isotope analysis were performed in order to determine the origin of bronze artefacts excavated from the Inyongsaji site in South Korea. The result of ICP-MS shows that they are tin bronzes in which lead was not intentionally added during production. Pb isotope data analyzed by TIMS are plotted in the southern region of Korea and China of the distribution map drawn by Mabuchi(1985). On the other hand, the identical isotope data are plotted in the Taebaek basin and the Olcheon metamorphic belt correspondent to zone2 and zone3 respectively. It is believed that the isotope data on the tin bronzes which have very low lead content can be used to trace the origin of copper ore rather than those of either lead or tin ore. Pb istope analysis allows diverse interpretation as it can be applied to any object containing trace amounts of lead. In addition, accumulation of isotope data as well as further studies will improve reliability of the provenance studies.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.224-233
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• 2018

Thirty-three Early Iron Age bronzes at the sites of Hoam-dong in Chungju and Cheongsong-ri in Buyeo were investigated in order to study the manufacturing technique and the provenance of lead. Chemical analysis using X-ray fluorescence showed that 33 bronzes consist of copper(Cu), tin(Sn) and lead(Pb) served as major elements. Major and minor elemental analyses by EPMA were performed on two mirrors and 2 weapons of the bronzes investigated. The results shows that bronze mirrors from Chungju and Buyeo were high-tin bronzes(> 30 wt%). And 20% of tin and 5% of lead were founded in bronze weapons. Iron, zinc, arsenic, silver, nickel, sulfur and cobalt detected in four bronzes as minor and trace elements. The four bronzes were alloyed considering their function and were not heat treated after casting due to their high tin content. Lead isotope analysis using TIMS indicates that thirty-three bronzes were distributed southern Korea peninsula except Zone 1. As a result, lead raw materials came from various regions in Korean Peninsula not from Gyeongsang-do regions. The manufacturing techniques of bronze ware generalized at this age, and bronze was produced in various sites using raw materials from various sources.

• Korean Journal of Materials Research
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• v.9 no.2
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• pp.188-194
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• 1999

To investigate the effect of niobium and tin on the mechanical properties of zirconium alloys, the tensile test and the microstructural analysis were performed on the Zr-based binary(Zr-xNb, Zr-xSn) and ternary(Zr-0.8Sn-xNb, Zr-0.4Nb-xSn) alloys. As the content of Nb or Sn element increased, the strengths of the Zr-based alloys tended to gradually increase. The increase of mechanical strength was remarkable strength was remarkable in the range more than the solubility of Nb and Sn. The strengthening effects were discussed on the basis of the solid solution hardening, the precipitate hardening, the grain size effect, and the texture effect. The mechanical strength is mainly controlled by the solid solution hardening and additionally by the precipitate hardening in the content more than solubility limit of Nb and Sn. The grain refinement also has a slight effect on the strength of the zirconium alloys with the addition of Nb and Sn. However, the texture effect can be excluded due to the same Kearns number regardless of the content of alloying elements.

• Journal of the Korean Electrochemical Society
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• v.7 no.3
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• pp.138-142
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• 2004

The polyaniline films of emeraldine base (EB) and leucoemeraldine base (LEB) form doped with cam-phorsulfonic acid (CSA) were prepared by casting the mixed solution of chloroform and m-cresol on ITO (indium tin oxide) electrode. By analyzing UV-vis spectra of the mixed solutions, the effects of the secondary doping by m-cresol were obtained. And the conductivity of polyaniline film was increased with increasing m-cresol content. As the results of analyzing cyclic voltammograms, it was known that the redox peak currents of polyaniline electrode prepared from LEB were larger and more reversible than those of polyaniline eleclrodes prepared from EB. The charge transfer resistances $(R_{ct})$ of polyaniline electrodes were reduced with increasing m-cresol content, showing smaller Rct for LEB/CSA than EB/CSA.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.244-252
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• 1990

Antitumor polyacetylenic alcohol, panaxytriol (Cl7 H26O3), was isolated and purified from a powder of the root of Pnnnx tin.1.encl C.A. Meyer. Panaxytriol possesses unusual property of being soluble in both water and organic solvents. Panaxytriol inhibited the growth of various kinds of human cultured cell lines in dose-dependent fashion in vitro. The in vivo effects of panaxytriol were tested against C57BL/6 mice transplanted with Bl6 melanomas. Panaxytriol (8 and 40 mg/kg) administered intra-muscularly(im) produced significant tumor growth delays in mice. Although a detailed mechanism of growth inhibition by panaxytriol is unknown, preliminary results appear to implicates a surface membrane site of action. And its action seems to be more dose-dependent than time-dependent. Finally, panaxytriol pharmacokinetics was evaluated in mice given single 8 mg/kg doses intraperitoneally (ip) or im. Serum panaxytriol content was measured using both tumor growth inhibitory assay and a gas chromatographic method. The maximum serum panaxytriol content after ip and im administration was 35.0 and 1.6 $\mu$g/ml respectively. These results indicate that the compound may act as cytotoxic substance even in patients.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.4
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• pp.239-245
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• 2000

Effect of tin and iron content on the recrystallization behavior of temary Zr-0.8Sn-x%Nb alloys were studied. The specimens with 0.1, 0.2 and 0.4 wt.% of iron were prepared under various annealing temperatures from $400^{\circ}C$ to $800^{\circ}C$ and times from 30 to 5000 minutes after vacuum arc remelting. The recrystallization behavior was observed using a polarized optical microscope, TEM and micro-vickers hardness tester. The recrystallization temperature of the alloys slightly increased with iron content due to increase of activation energy. The grain growth of the alloys with 0.1 and 0.2 wt.% of iron occured rapidly, however, that of the alloys with 0.4 wt.% iron was gradually retarded due to precipitation. The hardness of the alloy with a high iron slightly increased by the precipitation of beta phase after annealing at $800^{\circ}C$.

• Korean Journal of Materials Research
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• v.28 no.12
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• pp.685-690
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• 2018

In this study, a multifunctional ophthalmic lens material with an electromagnetic shielding effect, high oxygen permeability, and high water content is tested, and its applicability is evaluated. Metal oxide nanoparticles are applied to the ophthalmic lens material for vision correction to shield harmful electromagnetic waves; the pyridine group is used to improve the antibacterial effect; and silicone substituted with urethane and acrylate is employed to increase the oxygen permeability and water content. In addition, multifunctional tinted ophthalmic lens materials are studied using lens materials with an excellent antibacterial effect (2,6-difluoropyridine, 2-fluoro-4-pyridinecarboxylic acid) and functional (UV protection, high wettability) lens materials (2,4-dihydroxy benzophenone, 2-hydroxy-4-(methacryloyloxy)benzophenone). To solve problems such as air bubbles generated during the polymerization process for the manufacturing and turbidity of the lens surface, polymerization conditions in which the defect rate is minimized are determined. The results show that the polymerization temperature and time are most appropriate when they are $110^{\circ}C$ and 40 minutes, respectively. The optimum injection amount of the polymerization solution is 350 ms. The turbid phenomenon that appears in lens processing is improved by 10 to 95 % according to the test time and conditions.