• Title/Summary/Keyword: gold-silver

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Stability Analysis ofn HTS Current Lead with Constant Safety Factor (안전율이 일정한 초전도 전류도입선의 안정성해석)

  • Seol, Seoung-Yun
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.15-19
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    • 2000
  • The stability of variable cross-sectional area HTS current lead is considered. The cross-sectional area is varied to have a constant safety factor which is defined as the ratio of operating current and critical current of superconductor. As the constant area HTS lead, the variable cross-sectional area HTS lead also has three steady states above the bifurcation point and only one steady state below the bifurcation point. The temperature profiles and current sharing ratios for each steady state are calculated. The heat dissipation into cryogenic system for super-conducting, intermediate, and upper states are compared. For Bi-2333 sheathed with silver-gold alloy 2m length of current lead, and the maximum temperature of upper state seems to be burn-out free below 5m length.

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Geochemical Characteristics of Volcanics from Yangsan, Kyeongnam Province (경남(慶南) 양산지역(梁山地域)에 분포(分布)하는 화산암류(火山岩類)의 지구화학적(地球化學的) 특성연구(特性硏究))

  • Kim, M.Y.;Shin, H.J.;Lee, P.K.;Jang, Y.N.
    • Economic and Environmental Geology
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    • v.21 no.2
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    • pp.139-148
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    • 1988
  • The altered volcanic rocks, ranging from tuffaceous to andesitic rocks are widely distributed around the "caldera" area in the southeastern part of Kyeongsang province. The volcanic activity and tectonic movement are assumed to be followed by the hydrothermal activities in the area. From the mineral assemblage the type of alteration can be divided into two types; propylitic and argillic. The average concentration of gold in hydrothermally altered rocks is somewhat lower (about 20 ppb) than that of fresh rocks (45-25 ppb), but for Ag, vice versa. During the hydrothermal process, the concentration of the trace elements Ag, Hg, Co, As, Hf, Sc, Si, Al increased, and that of Na, Rb, K, Au, Mg, Ca etc. decreased. The high anomalous contents of silver for altered rocks range from 4-7 ppm and 1-3 ppm for relatively fresh rocks.

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A Study on the Attribute of Seun-Hee Choi′s Dancing Costumes and Its Interrelationship with Modern Costumes (최승희 무용의상의 특성과 현대패션과의 상관성)

  • 임영자;박유신
    • The Research Journal of the Costume Culture
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    • v.8 no.5
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    • pp.638-647
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    • 2000
  • The purpose of this study is to discover the interrelationship between modern costumes and Seung-Hee Choi's dancing costumes in 1930s. Seung-Hee Choi, who was a dancing pioneer in Korea, introduced the modern dancing costumes for the first time in Korea. The results are as followed ; First, we can find Eroticism in Choi's dancing dress. Choi's dancing costume had used gold thread, silver thread, spangle, see-through and a half-naked body clothing that decorated with beads and cords. It is similar to modern costumes in ubjet mtter, silhouette, design, and so on. Second, the influence of Futurism was in her dancing costumes, that is, it represented asymmetry designs and rectilineal figures. Third, not only beauty but also a Functionalism was expressed in her dancing costumes. Functional beauty was shown through bias cut, pleats, slit, and so on.

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Development of low-loss surface plasmon waveguides by using polymeric cladings (폴리머 크래딩을 이용한 저손실 표면플라즈몬 광도파로 개발)

  • Ju, Jeong-Jin;Park, Seon-Taek;Kim, Min-Su;Park, Seung-Gu;Kim, Jin-Tae;Choe, Jung-Seon;Gwon, Yong-Hwan;Lee, Myeong-Hyeon
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.02a
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    • pp.125-126
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    • 2008
  • We investigate characteristics of gold and silver metal strip waveguides based on long range surface plasmon polaritons (LRSPPs) along thin metal strips embedded in a polymer for practical applications at the wavelengths of 1.31 and 1.55 um. Guiding properties of the metal strip waveguides are theoretically and experimentally evaluated. In addition, surrounding technologies such as the development of TM-mode laser, coupling properties, as well as high-speed digital signal transporting experiments will be explained for board-to-board optical interconnections by using the LRSPP waveguides.

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Study on Organic Thin-Film Transistors(OTFTs) Devices with Gold and Nickel/Silver electrodes (전극에 따른 유기박막트랜지스터 소자의 전기적 특성 연구)

  • Hwang, Seon-Wook;Hyung, Gun-Woo;Park, Il-Houng;Choi, Hak-Bum;Kim, Young-Kwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.271-272
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    • 2008
  • We fabricated a pentacene thin-film transistor with Ni/Ag source/drain electrodes. Also, we obtained similar electrical characteristics as compared with source/drain electrode with Au. This device was found to have a field-effect mobility of about 0.021 $cm^2$/Vs, a threshold voltage of -5, -7 V, an subthreshold slope of 2.0, 4.5 V/decade, and an on!off current ratio of $3.6\times10^5$, $2.0\times10^6$.

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Contact and Electrical Characteristics of $\alpha$-67 Thin-Film for the fabrication of organic Thin-Film Transistor (유기 TFT 재작을 위한 $\alpha$&$-67 박막의 접촉 및 전기적 특성)

  • 오세운;김대엽;최종선;박미경;김영관;신동명
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.313-316
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    • 1998
  • Conjugated oligomers have been already used as active layers in field effect transistors, photodiodes and electroluminescent devices. Particularly thiophene oligomers such $\alpha$ -sexithiophene($\alpha$-6T) attract great interest for its prospective app1ications in large-area flexible displays. In this study, we investigated the contact properties between the organic semiconductor $\alpha$-6T and metals such as Au(Gold), Ag(Silver), Cr(Chromium), Al(Aluminum), Cr(Chromium). Using the Transmission Line Model(TLM) method, specific contact resistances of the metal lines in contact with the $\alpha$-6T were determined. From the current-voltage characteristics, electrical conductivity of the $\alpha$-6T films is found.

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Thiolated Protein A-functionalized Bimetallic Surface Plasmon Resonance Chip for Enhanced Determination of Amyloid Beta 42

  • Kim, Hyung Jin;Kim, Chang-Duk;Sohn, Young-Soo
    • Applied Chemistry for Engineering
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    • v.30 no.3
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    • pp.379-383
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    • 2019
  • The capability of detecting amyloid beta 42 ($A{\beta}42$), a biomarker of Alzheimer's disease, using a thiolated protein A-functionalized bimetallic surface plasmon resonance (SPR) chip was investigated. An optimized configuration of a bimetallic chip containing gold and silver was obtained through calculations in the intensity measurement mode. The surface of the SPR bimetallic chip was functionalized with thiolated protein A for the immobilization of $A{\beta}42$ antibody. The response of the thiolated protein A-functionalized bimetallic chip to $A{\beta}42$ in the concentration range of 50 to 1,000 pg/mL was linear. Compared to protein A without thiolation, the thiolated protein A resulted in greater sensitivity. Therefore, the thiolated protein A-functionalized bimetallic SPR chip can be used to detect very low concentrations of the biomarker for Alzheimer's disease.

Nanoparticles Modified With Cationic Thiol Surfactant as Efficient Inhibitors for the Corrosion of Carbon Steel

  • Azzam, Eid M.S.;Sami, Radwa M.;Alenezi, Khalaf M.;El Moll, Hani;Haque, A.
    • Journal of Electrochemical Science and Technology
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    • v.12 no.3
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    • pp.308-316
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    • 2021
  • In this work, we report synthesis, characterization and corrosion inhibition properties of cationic thiol surfactant-capped silver (SC-Ag-NPs) and gold (SC-Au-NPs) nanoparticles. SC-Ag-NPs and SC-Au-NPs were characterized using regular techniques include TEM. Corrosion study was carried out using carbon steel (CS) in 3.5% NaCl aqueous solution and characterized using multiple electrochemical techniques. Our results suggest that the paint containing SC-Ag-NPs and SC-Au-NPs endow efficient corrosion protection to the CS. Especially, SC-Au-NPs based paint form a stronger barrier between the metal and the corrosive ions, leading to better inhibition properties.

O Valor Documental dos Balangandãs: Uma Análise Simbólica e Formal

  • Carmo, Sura Souza;Borges, Luiz C.
    • Iberoamérica
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    • v.23 no.1
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    • pp.79-111
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    • 2021
  • The purpose of this article is to present the potential of balangandãs as a documentary source for intersectional studies of gender and slavery, from the analysis of formal and symbolic aspects of the museum objects in the Museu Nacional Nacional (MHN) and Museu Carlos Costa Pinto (MCCP). Balangandãs are a type of creole jewelry, made in gold or silver and used in Brazil since the 18th century by black women - women who worked, especially in the commercialization of foodstuffs in large urban centers. They are described in printed sources and engravings, and preserved in some museum institutions. In the study, the meanings attributed to the object over the centuries are observed: jewelry, amulet, peculium, document, travel memory and heritage. As a result, the article seeks to highlight the objects as a historical and documentary source, verifying similarities between the pieces musealized at the MHN and at the MCCP, also emphasizing the documental power of the pieces produced today.

Trend Analysis of LEED Certifications: Insights and Future

  • Lee, SeungMin;Kwak, Young Hoon
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1009-1016
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    • 2022
  • As environmental concerns grow, people are becoming more aware of energy efficiency, carbon reduction, and sustainable development. Leadership in Energy and Environmental Design (LEED) certification is currently the most widely recognized building environment assessment method connected to energy and the environment worldwide. This study explores trends for six factors (energy and atmosphere, materials and resources, indoor environmental quality, sustainable sites, water efficiency, and innovation in design) to assess four levels of LEED certification (Platinum, gold, silver, and certified) using 11,209 LEED projects in the United States. The study analyzes trends using scores of percentages of maximum points by certification level, ownership type, space type, and climate zones. With the interest in the Environmental, Social, and Governance (ESG) principle on the rise, this study contributes to a better understanding of the trends and future of LEED certification in the built environment sector.

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