• 보존과학연구
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• s.6
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• pp.121-196
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• 1985

Atomic absorption spectrophotometer was used for analyzing each 10elements(Cu, Pb, Sn, Zn, Sb, Fe, Ni, Ag, Co and Mn)on 64 Chinese coinsre covered from Shinan seabed sunken ship. The results show that Cu, Pb and Sn were found to be a major elements consisting of coins and its composition ratio was 6 to 2 to 1.The composition of trace elements on coins was classified 3 levels : Sb, Fe and Zn(0.02%-2.2%), Ag, Ni, and Co(50 ppm-5500 ppm) and Mn(Trace). Theam ount of major elements, Cu and Sn were decreased while increased in Pbby the passage of ages (10th - 13th century) in China. There seems to be no systematic compositional change in major elements but content in trace elements was confirmed to increase with age.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.344-345
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• 2006

In this study, in order to develop low temperature sintering piezoelectric transformer, $(Pb_{0.99-x}Ca_xSr_{0.01})Ti_{0.96}(Mn_{1/3}Sb_{2/3})_{0.04}O_3$ ceramic systems were fabricated using $Na_2CO_3-Li_2CO_3$ as sintering aids and investigated with the amount of Ca substitution. The piezoelectric transformer requires high electromechanical coupling factor $k_t$ and high mechanical quality factor $Q_{mt}$ for generating high output power At the ($PbCaSr)Ti(MnSb)O_3$ ceramics with 24mol% Ca substitution sintered at $900^{\circ}C$, electromechanical coupling factor $k_t$ and mechanical quality factor $Q_{mt}$ showed the optimal values of 0.504 and 1655 respectively, for thickness vibration mode multilayer piezoelectric transformer application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.926-931
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• 2000

The microwave dielectric properties and the microstructures as a mole fraction of (1-x)ZnNb$_2$O$_{6}$-xPb$_{5}$Nb$_4$O$_{15}$ ceramics with CuV$_2$O$_{6}$, Sb$_2$O$_3$ and glass(ZNPN ceramics) was investigated. 0.98ZN-0.02PN ceramics containing 1.5 wt% CuV$_2$O$_{6}$ 1.0 wt% Sb$_2$O$_3$ and 1.0 wt% glass had a dielectric constant($\varepsilon$$_{r}$) of 23, Qxf$_{o}$ value of 15000 and TCF(Temperature Coefficient of resonance Frequency) of -25 ppm/$^{\circ}C$ and it is possible to be co-fired with Ag electrode at 90$0^{\circ}C$. As sintered temperature increases over 90$0^{\circ}C$ the grain size of ZNPN ceramics was increasing for growth and it has poor co-fired properties with Ag electrode.e.ctrode.e.e.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.10
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• pp.630-634
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• 2014

$(Na_{0.525}K_{0.4425}Li_{0.0375})(Nb_{0.9975}Sb_{0.065}Ta_{0.0375})O_3+0.3 wt%CoO$ ceramics were fabricated as a function of CuO addition by traditional solid state sintering process in order to develop excellent lead-free piezoelectric ceramics composition. The addition of CuO in the LNKNTS composition ceramics can effectively enhance the densification of the ceramics, resulting in the oxygen vacancies as hardening effect. The excellent piezoelectric properties of electromechanical coupling factor($k{\small}_P$) of 0.378, piezoelectric constant($d_{33}$) of 152 pC/N were obtained from the 1.0 mol% CuO doped LNKNTS ceramics sintered at $1,020^{\circ}C$ for 3 h.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.281-288
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• 2008

Polyacrylonitrile(PAN)/metal oxide(MO) nanocomposite mats with a thickness of 0.12 mm were electrospun by adding 0 to 10 wt% of MO nanoparticles ($Fe_2O_3$, ZnO, $SnO_2$, $Sb_2O_3-SnO_2$) into PAN. Pt electrode was patterned on $Al_2O_3$ substrate by DC sputtering and then the PAN(/MO) mats on the Pt patterned $Al_2O_3$ were electrically wired to investigate the $CO_2$ gas sensing properties. As the MO content rose, the fiber diameter decreased due to the presence of lumps caused by the presence of MOs in the fiber. The PAN/2% ZnO mat revealed a faster response time of 93 s and a relatively short recovery of 54 s with a ${\Delta}R$ of 0.031 M${\Omega}$ at a $CO_2$ concentration of 200 ppm. The difference in sensitivity was not observed significantly for the PAN/MO fiber mats in the $CO_2$ concentration range of 100 to 500 ppm. It can be concluded that an appropriate amount of MO nanoparticles in the PAN backbone leads to improvement of the $CO_2$ gas sensing properties.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1038-1045
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• 2006

A series of experiments was conducted to test the compatibilities of two different techniques to determine elemental concentrations by INAA and ICP-MS based on both the NIST SRM 2783(air particulate on filter media) and the field samples for PM10. For NIST SRM the results of INAA were more accurate and precise for all target elements than those of ICP-MS. The comparative data set for PM10 samples collected in an industrial complex area showed that mean of concentration ratio, derived for the two different methods such as C(INNA/ICP-MS), were distinguished from each other: (1) Ba, Cu, K Mg, Na, and Sb: $0.9{\sim}1.1$; (2) Al, Co, Fe, and Mn: $0.8{\sim}1.2$; and (3) Se, Ti, and Zn: >1.3. When the results obtained from both methods were evaluated in terms of regression analysis, paired t-test, and Wilcoxon signed-rank test, the results of many elements determined from PM10 samples(such as Al, Ba, Co, Cu, Fe, K, Mn, Nd, and Sb) exhibited a fairly good agreement between the two methods, despite a wide range of variation.

• Journal of the Korean Ceramic Society
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• v.52 no.2
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• pp.114-118
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• 2015

$V_2O_5-P_2O_5-ZnO-Sb_2O_3$ glasses modified with BaO and $Al_2O_3$ are synthesized as a sealing material for large-scale dye-sensitized solar cells (DSSCs). A compositional study is performed in order to determine the glass that can be sintered below $500^{\circ}C$ with a high chemical stability against the electrolyte. The flow size of the glasses after the heat treatment and the glass stability are increased with the addition of $Al_2O_3$ and BaO, while the glass transition temperature is decreased. After the reaction with the electrolyte at $60^{\circ}C$ for 72 h, the addition of 5 mol% of BaO and 2 mol% of $Al_2O_3$ considerably enhances the chemical stability of the glass. X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to examine the reaction between the electrolyte and glasses. The structural contribution of the additives is also investigated and discussed.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.155-166
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• 1993

Gold contents with major and trace elements have been determined in 67 fresh igneous and altered wall rocks in the acid-sulfate alteration zone of the Ogmaesan-Seongsan pyrophyllite deposits in the Haenam area of the south-western part of Korean peninsula. The results are as follows; (1) Li contents have a tendency to show high value in dickite and altered rocks with dickite, while As, Mo and Sb contents have tendencies to show high values in alunite vein and silicified zone. F contents are higher in the altered rocks compared to fresh rocks. (2) Gold contents are enriched in alunite vein and silicified zone of the Seongsan deposit, but depleted in dickite and altered rock with dickite. Gold contents are especially concentrated in fault or conjunction area of two faults. (3) Gold contents are higher values in the mineral assemblages of alunite-quartz-pyrite and alteration zone of the Seongsan deposit among the studied deposits. (4) Gold contents in samples of silicified zones tend to show positive correlations with Ag, As, Co, Hg, Sb and V content, but negative correlations with Y and Zr contents, while on the other gold contents of silicified tuffs tend to show positive correlations with Hg and Sb contents. Therefore it is important to survey alunite vein and silicified zone at the conjunction of faults, and to analyze pathfinder elements such as Ag, As, Hg and Sb for geological and geochemical exploration of gold in the studied deposits.

• Journal of the Korean Vacuum Society
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• v.21 no.6
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• pp.348-353
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• 2012

We investigated chemical states of a $Sb_2Te_3$ thin film with the polycrystalline phase by using high-resolution x-ray photoelectron spectroscopy with synchrotron radiation. The $Sb_2Te_3$ thin film was formed by sputtering. The rhombohedral phase was confirmed by x-ray diffraction. To remove the surface oxide, we performed $Ne^+$ ion sputtering for 1 hour with the beam energy of 1 kV and post-annealing at $100^{\circ}C$ for 5 min in ultra-high vacuum. We obtained the Te and Sb 4d core-levels spectra with the peaks at the binding energies of 40.4 and 33.0 eV, respectively. The full-width of half maximum of both the Te and Sb $4d_{5/2}$ core-levels is 0.9 eV. The Te and Sb core-levels only show a single chemical state, and we also confirmed the stoichiometry of approximately 2 : 3.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.1-7
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• 2011

Undoped and Sb-doped $SnO_2$ nanofibers were prepared by electrospinning and their responses to $H_2$, CO, $CH_4$, $C_3H_8$, and $C_2H_5OH$ were measured. In the undoped $SnO_2$ nanofibers, the gas response ($R_a/R_g$, $R_a$: resistance in air, $R_g$: resistance in gas) to 100 ppm $C_2H_5OH$ was very high(33.9), while that to the other gases ranged from 1.6 to 2.2. By doping with 2.65 wt% Sb, the response to 100 ppm $C_2H_5OH$ was decreased to 4.5, whereas the response to $H_2$ was increased to 3.0. This demonstrates the possibility of detecting a high $H_2$ concentration with minimum interference from $C_2H_5OH$ and the potential to control the gas selectivity by Sb doping.