• Journal of the Korean Ceramic Society
• /
• v.39 no.6
• /
• pp.589-593
• /
• 2002

The single crystalline thick fi1ms of Bi:Y$_3$Fe$_{5}$ $O_{12}$(Bi:YIG) were grown on (GdCa)$_3$(GaMgZr)$_{5}$ $O_{12}$(SGGG) by Liquid Phase Epitaxy (LPE). The changes of lattice mismatch and Bi concentration were investigated in the thick film growth as a function of PO/Bi$_2$ $O_3$ molar ratio, with keeping constant of substrate rotation speed, supercooling and growth time. It was grown that the lattice constant of the garnet single crystalline thick films and Bi content increased with decreasing of PO/Bi$_2$ $O_3$ molar ratio. Bi concentration decreased with increasing of the film thickness.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.1
• /
• pp.89-94
• /
• 2007

High duality BiSrCaCuO thin films fabricated by using the i-beam sputtering method at various substrate temperatures, $T_{sub}$ and oxidation gas pressures, $pO_3$. The correlation diagrams of the BiSrCaCuO phases with Tsub and $pO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

• Journal of Electrochemical Science and Technology
• /
• v.14 no.1
• /
• pp.21-30
• /
• 2023

This work presents a correlation between the behavior of formic acid oxidation (FAO) on various Bi-modified Pt(poly) disk electrodes and their morphologies observed on Bi-modified Pt(111) disk electrodes using electrochemical scanning tunneling microscopy (EC-STM) to understand the effects of Bi on Pt. To distinguish the FAO activities of Bi on Pt and plain Pt around Bi, additional Pt was intentionally deposited using two different routes: direct route and iodine route. In direct route, Pt was directly deposited on Bi islands and plain Pt sites around Bi islands, while in iodine route, Pt was exclusively deposited on Bi islands by protecting plain Pt sites with adsorbed iodine. Thus, a comparison of FAO performances on the two Bi-modified Pt electrodes with additional Pt (deposited in the different ways) disclosed a difference in FAO performances on plain Pt sites and Bi islands. When Bi coverage was ~0.04, the Bi deposits were scattered Bi islands enhancing FAO on Pt(poly). The additional Pt deposits using direct route increased FAO efficiency, while the ones using iodine route slightly decreased FAO current. The EC-STM observations indicated that Pt deposits around Bi islands, not on Bi islands, were responsible for the FAO current increase on Bi-modified Pt(poly). The FAO efficiency on Bi-modified Pt(poly) with a Bi coverage of ~0.25 increased by a factor of 2. However, the additional Pt deposits using the two Pt deposition routes notably decreased the FAO current. The dependency of FAO on Bi coverage was discussed in terms of electronic effect and ensemble effect.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.5
• /
• pp.2142-2148
• /
• 2011

Managers in Business Incubator(BI) perform an important role to success of BI, but researches about what area of capability need to improve are limited. This study investigates the perceived gap between current capability and required capability of BI managers from BI managers' and CEOs' perspectives with a survey method. From the BI managers' perspective, improvement of most capabilities, such as financing support, R&D support and understanding of patents, and understanding of business of firms in BI, is needed. From CEOs' perspective, improvement of capability in financing and marketing support is needed.

• Progress in Superconductivity
• /
• v.4 no.2
• /
• pp.148-152
• /
• 2003

We have observed the temperature dependences of Bi $L_{III}$ edge spectra by extended X-ray absorption spectroscopy for a high quality single crystal and a powder of the $Ba_{0.6}K_{0.4}BiO_3$ superconductor. $Ba_{0.6}K_{0.4}BiO_3$ has the cubic structure and metallic states. The deformation of the $BiO_{6}$ octahedra, which is due to the anomalies of the Bi-O and Bi-Ba bond length, was showed by the double-shell fit. It was clearly found that these anomalies are owing to the difference in the strength of Bi-O bonds. The temperature dependences of both bond lengths and the Debye-Walter factor ${\sigma}^2$ of the Bi-O and Bi-(Ba,K) bond are discussed to illustrate local structural features of the $Ba_{0.6}K_{0.4}BiO_3$

• Economic and Environmental Geology
• /
• v.39 no.6 s.181
• /
• pp.643-651
• /
• 2006

The Pb-Ag-Bi-S system minerals such as galena-matildite solid solutions, cosalite and heyrovskyite occur in the Nakdong As-Bi deposits. Galena-matildite solid solutions commonly coexisting with native bismuth fill in microfractures of pyrite grains and form irregular shapes. Cosalite forms composite grains including native bismuth, heyrovskyite and Bi-Te-S system minerals in the matrix of quartz vein. Matildite from the Nakdong deposits has an end member composition, $Ag_{1.07-1.11}Bi_{1.12-1.20}S_2$, and an excess concentration of $0.3{\sim}2.4$ mole % $Bi_2S_3$ compared to the stoichiomeoic value. PbS concentrations in $PbS-AgBiS_2$ solid solutions do not exceed 54 mole %. The average chemical composition of cosalite in the study area is $Pb_{1.79}Bi_{2.29}Ag_{0.12}S_5$. Pb is slightly depleted compared to the ideal composition, but the concentrations of Ag and Cu reach as much as 1.47 wt.% and 0.27 wt.%, respectively. Heyrovskyite has the chemical formula of $Pb_{5.01}Ag_{0.26}Bi_{2.70}S_9$ suggesting that there occurs the coupled substitution of $2Bi^{3+}$ for $3Pb^{2+}$ as well as that of $Ag^++Bi^{3+}$ for $2Pb^{2+}$. The genetic condition of Pb-Ag-Bi-S system minerals can be confined to the temperature of $220{\sim}270^{\circ}C$ and the pressure below 200 bars.

• Journal of the Microelectronics and Packaging Society
• /
• v.8 no.4
• /
• pp.25-33
• /
• 2001

Sn-3.5Ag-xBi alloys with five different levels of Bi (0, 2.5, 4.8, 7.5, 10 wt%) were prepared for evaluating creep properties. Cast alloys were roiled and heat treated to provide stable microstructures during the subsequent creep tests, which were conducted under constant load using dog-bone specimens. For the Bi containing alloys, creep strength showed the maximum around 2.5 wt%Bi and tended to decrease with increasing Bi content. The stress exponent of the alloy was around 4, suggesting typical dislocation creep, but the exponent was 2 for the 10 wt%Bi alloy, suggesting creep assisted by grain boundary Sliding. For the Bi containing alloys, the brittle fracture mode appeared showing small amount of reduction of area, while the ductile fracture mode was true for the Bi free alloy. Microstructural examination of ruptured specimens showed cavitations on grain boundaries normal to the load axis, and a significant of grain boundary sliding for the Bi containing alloys.

• Journal of Electrochemical Science and Technology
• /
• v.12 no.3
• /
• pp.323-329
• /
• 2021

This work presents a contrasting behavior of formic acid oxidation (FAO) on the Pt and Bi deposits on different Pt substrates. Using irreversible adsorption method, Bi and Pt were sequentially deposited on Pt electrodes of nanoparticle (Pt NP) and disk (Pt disk). The deposited layers of Bi and Pt on the Pt substrates were characterized with X-ray photoelectron spectroscopy, transmission microscopy and scanning tunneling microscopy. The electrochemical behaviors and FAO enhancements of Pt NP and Pt disk with deposited Bi only (i.e., Bi/Pt NP and Bi/Pt disk), were similar to each other. However, additional deposition of Pt on Bi/Pt NP and Bi/Pt disk (i.e., Pt/Bi/Pt NP and Pt/Bi/Pt disk) changed the electrochemical behavior and FAO activity in different ways depending on the shapes of the Pt substrates. With Pt/Bi/Pt NP, the hydrogen adsorption was suppressed and the surface oxidation of Pt was enhanced; while with Pt/Bi/Pt disk, the opposite behavior was observed. This difference was interpreted as a stronger interaction between the deposited Bi and Pt on Pt NP than that on Pt disk. The FAO performance on Pt/Bi/Pt NP is much better than that on Pt/Bi/Pt disk, most likely due to the difference in the interaction between the deposited Pt and Bi depending on the shapes of Pt substrates. In designing FAO electrochemical catalysts using Pt and Bi, the shape of a Pt substrate was concluded to be critically considered.

• Speech Sciences
• /
• v.9 no.1
• /
• pp.89-110
• /
• 2002

Intonation is very difficult to describe and it is furthermore difficult to compare intonation between different languages because of their differences of intonation systems. This paper aims to compare some intonation phenomena between Korean, French and English. In this paper I will refer to ToBI (the Tone and Break Indices) which is a prosodic transcription model proposed originally by Pierrehumbert (1980) as a description tool. In the first part, I will summarize different ToBI systems, namely, K-ToBI (Korean ToBI), F-ToBI (French ToBI) and ToBI itself (English ToBI) in order to compare the differences of three languages within prosody. In the second part, I will analyze some tokens registered by Korean, French and American in different languages to show the difficulties of learning other languages and to find the prosodic cues to pronounce correctly other languages. The point of comparison in this study is the Accentual Phrase (AP) in Korean and in French and the intermediate phrase (ip) in English, which I will call ' subject phrase ' in this study for convenience.

• Journal of the Korean Vacuum Society
• /
• v.1 no.2
• /
• pp.244-253
• /
• 1992

BiSI, BiSI : Co, BiSeI 및 BiSeI : Co 단결정을 고순도의 성분원소와 8.6mole% 과잉의 Iodine를 투명석영관내에 넣고 진공봉입하여 합성한 ingot를 사용하여 수직 Bridgman 방법으로 성장시켰다. 성장된 단결정은 orthorhombic 구조였고, energy band 구 조는 간접전이형으로 293K에서 광학적 energy gap은 각각 1.590eV, 1.412eV, 1.282eV 및 1.249eV로 주어지며, energy gap의 온도의존성은 Varshni 방정식으로 잘 표현된다. Cobalt 를 첨가할 때 나타나는 불순물 광흡수 peak는 Td symmetry점에 위치한 Co2+, Co3+ ion의 energy 준위들 사이의 전자전이에 의해서 나타난다.