• Title/Summary/Keyword: ToBI

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The study of the $BiO_{6}$ octahedra structure in superconducting $Ba_{0.6}K_{0.4}BiO_3$ single crystal by extended x-ray absorption spectroscopy (EXAFS에 의한 $Ba_{0.6}K_{0.4}BiO_3$ 단결정의 초전도 상태에서 $BiO_{6}$ octahedra 구조의 연구)

  • 김봉준;김영철;김현탁;강광용;이재민
    • Progress in Superconductivity
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    • v.4 no.2
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    • pp.148-152
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    • 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 $Ba_{0.6}K_{0.4}BiO_3$

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The Effect of Bi Content on the C-axis Oriented Growth of $SrBi_2$$Ta_2$$O_9$ Thin Films Fabricateed by R.F. Magnetron Sputtering (R.F. 마그네트론 스퍼터링에 의한 제조된 $SrBi_2$$Ta_2$$O_9$ 박막의 C축 배향성장에 미치는 Bi양의 영향)

  • 배철휘;이전국;이시형;정형진
    • Journal of the Korean Ceramic Society
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    • v.35 no.10
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    • pp.1107-1112
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    • 1998
  • We could obtan c-axis oriented $SrBi_2$$Ta_2$$O_9$ thin films on usual Pt(111)/Ti/$SiO_2$/Si(100) substrate using a r. f. magnetron sputtering technique. According to the increase of sputtering pressure from 250 to 300 mTorr the Bi content and degree of the c-a xis preferred orientation of $SrBi_2$$Ta_2$$O_9$ thin films were increased. By controlling Bi(or $Bi_2O_3$) loss from $SrBi_2$$Ta_2$$O_9$ thin films during post annealing and by inserting $Bi_2O_3$ layer in $SrBi_2$$Ta_2$$O_9$ thin films the effect of Bi content on the c-axis oriented growth of $SrBi_2$$Ta_2$$O_9$ thin films could be investigated without the effect of sputtering pressure. The degree of the c-axis preferred orientation of $SrBi_2$$Ta_2$$O_9$ thin films was increased with increasing with increasing Bi content by control of Bi(or $Bi_2O_3$) loss of $SrBi_2$$Ta_2$$O_9$ thin films. But the c-axis oriented growth of $SrBi_2$$Ta_2$$O_9$ thin films disappeared by the inserting of $Bi_2O_3$ lay-er in $SrBi_2$$Ta_2$$O_9$ thin films.

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Are Critical Success Factors of BI Systems Really Unique?

  • Kim, Sung Kun;Kim, Jin Yong
    • Journal of Information Technology Applications and Management
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    • v.24 no.1
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    • pp.45-61
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    • 2017
  • Business intelligence has been attracting much attention these days. Despite such popularity of BI systems, it is widely known that about a half of BI system projects have failed. To grasp why many BI projects end in failure and what factors would make BI projects less failure-prone, a number of BI studies were made to produce a variety of CSFs. However, there is a paucity of information on whether these CSFs are distinctive from those of typical information systems. By identifying how BI CSFs differ from CSFs of typical information systems, we would be able to explain why most BI projects are more likely to be failure. It is believed that a corrective measure about CSFs will lead to more success in future BI projects. In addition, though there have been a number of similar types of BI systems such as decision support systems and executive information systems in existence, there was no study to determine whether there is ever a discrimination between CSFs of BI systems and the similarly-titled systems. This study is to answer these questions using a literature review analysis. The findings of our study are expected to be helpful in a successful implementation of BI systems.

The Ways for Bi on Pt to Enhance Formic Acid Oxidation

  • Hyein Lee;Young Jun Kim;Youngku Sohn;Choong Kyun Rhee
    • Journal of Electrochemical Science and Technology
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    • v.14 no.1
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    • pp.21-30
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    • 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.

Technique development of Bi-2212/2223 superconductor thick film manufacturing by plasma spraying and heat treatment (플라즈마 용사 및 열처리 공정을 통한 Bi-2212/2223 초전도체 thick film 제조의 기술 개발)

  • Lee, Seon-Hong;Cho, Sang-Hum;Ko, Young-Bong;Park, Kyeung-Chae
    • Proceedings of the KWS Conference
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    • 2005.11a
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    • pp.262-264
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    • 2005
  • $Bi_{2}Sr_{2}CaCu_{2}O_{x}$(Bi-2212) and $Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{y}$(Bi-2223) high-$T_{c}$ superconductor(HTS) coating have been prepared by plasma spraying and heaat treatment. The Bi-2212 HTS coating later is synthesized through the peritectic reaction between Sr-Ca-Cu oxide coating layer and Bi-Cu oxide coating later, and $Bi_{2}Sr_{2}CaCu_{2}O_{y}$(Bi-2212) superconducting phase grow by partial melting process. The superconducting characteristic depends strongly on the conditions of the partial melting process. the Bi-2212 HTS layer consists of the whiskers grown in the diffusion direction. Above the 2212 layer, Bi-2223 phase and secondary phase was observed. The secondary phase is distributed uniformly over the whole surface. This is caused to the microcrack on the coatings surface. Despite everything, the film shows superconducting with an onset $T_{c}$ of about 115K. There are two changes steps. One changes (1step) at 115K is due to the diamagnetism of the Bi-2223 phase and the other changes (2step) at 78K is due to the diamagnetism of the Bi-2212 phase.

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Synthesis and Characterization of 1-D BiSI and 2-D BiOI Nanostructures

  • Lee, Juheon;Min, Bong-Ki;Cho, Insu;Sohn, Youngku
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.773-776
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    • 2013
  • We have prepared 1-D BiSI and 2-D BiOI nanostructures, and characterized them by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction crystallography, thermogravimetric analysis/differential scanning calorimetry, and UV-visible absorption. Here, we first report clear HR-TEM image of BiSI. In addition, we first found that the growth direction of BiSI is [12-1] plane, with the neighboring distance of 0.30 nm. The crystal structures of BiSI and BiOI are found to be orthorhombic (Pnam) and tetragonal (P4/nmm), respectively. The absorption band gaps of BiSI and BiOI are measured to be 1.55 and 1.92 eV, respectively. Our study could further highlight the applications of V-VI-VII compounds.

Creep Properties of Sn-3.5Ag-xBi Solders (Sn-3.5Ag-Bi 솔더의 크리프 특성)

  • Shin, S. W.;Yu, Jin
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.4
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    • pp.25-33
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    • 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.

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Pt Deposits on Bi-Modified Pt Electrodes of Nanoparticle and Disk: A Contrasting Behavior of Formic Acid Oxidation

  • Lee, Hyein;Kim, Young Jun;Sohn, Youngku;Rhee, Choong Kyun
    • Journal of Electrochemical Science and Technology
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    • v.12 no.3
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    • pp.323-329
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    • 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.

A study on the type of Bi(肥) and Su(痩) of Body in 'Yellow Emperior's Nei-Ching' (${\ll}$내경(內徑)${\gg}$을 중심(中心) 한 체형(體型)의 비수(肥痩)에 대(對)한 고찰(考察))

  • Chun, Tae Kang;Hong, Won Sik
    • Journal of Korean Medical classics
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    • v.6
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    • pp.176-188
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    • 1993
  • After studing on the type of Bi(肥) and Su(痩) of Body in 'Yellow Emperior's Nei-Ching', I reached the following conclusions; 1. The specific charactor of bi(肥) and su(痩) were explained in table 1. 2. The specific charactor of gi(脂), ko(膏) and youk(肉) were explaned in table 2. 3. Obserbing the type of bi(肥) and su(痩) by the view of YinYang(陰陽), bi(肥) belongs to Yin(陰) and su(痩) belongs to Yang(陽). Also the each of bi(肥) and su(痩) could obserbed by the view of YinYang(陰陽). The type of su(痩) easily becomes to yanghea(陽虛) because chi(氣) easely becomes to exhaust also easely becomes to yinhea(陰虛) because blood(血) easely becomes to exhaust. So the outer of body is cold, the inner of body is hot. The type of bi(肥) easely causes YinYang(陰陽) to exceed because blood(血) easely becomes to black and turbid(血黑以濁), chi(氣) easely becomes to rough and slow(氣澁以遲). So the outer of body is hot, the iner of body is cold 4. Obserbing the type of bi(肥) and su(痩) by the view of viscera, in view of upper and lower(上下觀點) su(痩) is yang(陽) so heart and lung belongs to su(痩) bi(肥) is yin(陰) so liver and kidney belongs In bi(肥). in view of inner and outer(內外觀點) su(痩) is inner(內) so heart 3I1d liver belongs In su(痩) bi(肥) is outer(外) so lung and kidney belongs to bi(肥). 5. Obserbing the type of bi(肥) and su(痩) by the view of body constitution(體質), partially body constitution was divided into gi(脂), ko(膏) and youk(肉), entirely there was OhtaeinLon(五態人論) and four constitutional medicine(四象醫學) I thing that taeyangin(太陽人) and soyangin(少陽人) belong to su(痩), taeyinin(太陰人) and soyinin(少陰人) belong to bi(肥).

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A Nucleotide Exchange Factor, BAP, dissociated Protein-Molecular Chaperone Complex in vitro (In vitro에서 핵산치환인자 BAP이 단백질-분자 샤페론 복합체 해리에 미치는 영향)

  • Lee Myoung-Joo;Kim Dong-Eun;Lee Tae-Ho;Jeong Yong-Kee;Kim Young-Hee;Chung Kyung-Tae
    • Journal of Life Science
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    • v.16 no.3 s.76
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    • pp.409-414
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    • 2006
  • Molecular chaperones and folding enzymes in the endoplasmic reticulum (ER) associate with the newly synthesized proteins to prevent their aggregation and help them fold and assemble correctly. Chaperone function of BiP, which is a Hsp70 homologue in ER, is controlled by the N-terminal ATPase domain. The ATPase activity of the ATPase domain is affected by regulatory factors. BAP was identified as a nucleotide exchange factor of BiP (Grp78), which exchanges ADP with ATP in the ATPase domain of BiP This study presents whether BAP can influence folding of a protein, immunoglobulin heavy chain that is bound to BiP tightly. We first examined which nucleotide of ADP and ATP affects on BAP binding to BiP The data showed that endogenous BAP of HEK293 cells prefers ADP for binding to BiP in vitro, suggesting that BAP first releases ADP from the ATPase domain in order to exchange with ATP. Immunoglobulin heavy chain, an unfolded protein substrate, was released from BiP in the presence of BAP but not in the presence of ERdj3, which is another regulatory factor for BiP accelerating the rate of ATP hydrolysis of BiP The ADP-releasing function of BAP was, therefore, believed to be responsible for immunoglobulin heavy chain release from BiP. Grp170, another Hsp70 homologue in ER, did not co-precipited with BAP from $[^{35}S]$-metabolic labeled HEK293 lysate containing both overexpressed Grp170 and BAP. These data suggested that BAP has no specificity to Grp170 although the ATPase domains of Grp170 and BiP are homologous each other.