• Title/Summary/Keyword: antimony

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ATO Thin Films Prepared by Reactive lout Beam Sputtering (반응성 이온빔 스퍼터링법에 의해 제조된 ATO박막)

  • 구창영;김경중;김광호;이희영
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.361-364
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    • 2000
  • Antimony doped tin oxide (ATO) thin films were deposited at room temperature by reactive ion-beam sputter deposition (IBSD) technique in oxidizing atmosphere utilizing Sb and Sn metal targets. Effect of Sb doping concentration, film thickness and heat treatment on electrical and optical properties was investigated. The thickness of as-deposited films was controlled approximately to 1500 $\AA$ or 2000$\AA$, and Sb concentration to 10.8 and 14.9 wt%, as determined by SEM and XPS analyses. Heat treatment was performed at the temperature from 40$0^{\circ}C$ to 80$0^{\circ}C$ in flowing $O_2$or forming gas. The resulting ATO films showed widely changing electrical resistivity and optical transmittance values in the visible spectrum depending on the composition, thickness and firing condition.

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The Improvements for Fire Retardancy and Radiation Resistance of Chloroprene Rubber (클로로프렌 고무의 난연성 및 내방사선 특성 향상)

  • Kim, Ki-Yup;Lee, Chung;Ryu, Boo-Hyung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.11
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    • pp.1205-1211
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    • 2004
  • This study has investigated radiation degradation of chloroprene rubber in the presence of some fire retardant. Ammonium polyphosphate, aluminium trihydroxide, magnesium hydroxide, calcium carbonate and antimony trioxide were selected as flame retardant. Samples were irradiated using a Co$^{60}$ ${\gamma}$ -ray and ray up to 2000 kGy at a dose rate of 5 kGy/hr in the presence of air atmosphere at room temperature. After irradiation, samples were assessed fire retardancy with electrical properties and mechanical properties. Some considerations concerning the effects of the fire retardants added to chloroprene rubber on the radiation and thermal stability of chloroprene rubber are presented. From fire retardancy with electrical and mechanical property measurements, it was found that addition of magnesium hydroxide resulted in maximum fire retardant effect.

A UBET Analysis of Non-axisymmetric Forward and Backward Extrusion (비축대칭 전후방압출공정의 UBET해석)

  • Lee, Hee-In;Kim, Jin-Kyu;Hwang, Bum-Chul;Bae, Won-Byong
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.1
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    • pp.154-161
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    • 2001
  • A UBET analysis has been carried out to predict the forming load and the extruded length of forward and backward extrusion of hexagonal and trochoidal wrench colts. For the upper bound load and the average length of the extruded billets are determined by minimizing the total energy consumption rate which is a function of unknown velocities and parameters at each element. Experiments are carried out with antimony-lead billets at room temperature using hexagonal and trochoidal shaped punches. The theoretical predictions of the forming load and the extruded length are in good agreement with the experimetal results.

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An Upper-Bound Analysis of the Socket Forming Process (Socket Forming에 관한 상계해석)

  • Hwang, Bum-Chul;Hong, Seung-Jin;Bae, Won-Byong
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.8
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    • pp.151-156
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    • 2000
  • A kinematically-admissible velocity field is proposed to determine the forming load the average extruded length and the velocity distribution in the forward and backward extrusion process of a socket. Experiments are carried out with antimony-lead billets at room temperature using the rectangular punch and the hexagonal die. The theoretical predictions of the forming load and the average extruded length are in good agreement with the experimental results.

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A Study on the Characterization on Some Semiconuctor Materials by Neutron Activation Analysis. Characterization of Semiconductor Silicon

  • Lee Chul;Kwun Oh Cheun;Kim Ho Kun;Lee Jong Du;Chung Koo Soon
    • Bulletin of the Korean Chemical Society
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    • v.10 no.1
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    • pp.30-32
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    • 1989
  • Traces of nine elements, gold, arsenic, cobalt, chromium, copper, europium, hafnium, sodium and antimony in commercially available silicon crystals were determined by the instrumental neutron activation analysis using the single comparator method. The values of the concentrations of these elements in both single and polycrystals were found to decrease significantly to a low limiting level by simply washing and etching surface contaminants having been introduced during various steps of sample preparation and irradiation. However, the chromium levels in polycrystals were not easily decreased, these depending upon the cutting tools employed. The Sb-doped content in each semiconductor has been compared with the associated quantities such as the concentration and the conductivity range given by the sample donor. Uncertainty in the sodium analysis due to the fission neutron reaction by silicon itself was discussed.

FT-IR analysis of flame resistant chemical mixture

  • Kim, Younsu;Seo, Jihyung;Choe, Yoong Kee;Sohn, Youngku;Kim, Jeongkwon
    • Analytical Science and Technology
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    • v.34 no.1
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    • pp.17-22
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    • 2021
  • In this study, flame retardant mixtures of decabromodiphenylethane (DBDPE) and Sb2O3 were analyzed using Fourier transform infrared (FT-IR) spectroscopy. The experimentally obtained wavenumbers of DBDPE and Sb2O3 were 1321 and 949 cm-1, respectively, whereas those obtained by theoretical calculation were 1370 and 818 cm-1, respectively. Strong correlation was observed between the mixing molar ratios and observed peak area ratios, suggesting that FT-IR analysis can be used to obtain relative amounts of the individual components of flame retardant mixture.

Use of Mammary Lymphoscintigraphy and Intraoperative Radioguided Gamma Probe in Sentinel Lymph Node Biopsy of Breast Cancer (유방암 환자의 전초림프절 생검에서 유방림프신티그라피와 수술 중 감마프로우브의 유용성)

  • Kim, Soon;Zeon, Seok-Kil;Kim, Yu-Sa
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.6
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    • pp.478-486
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    • 2000
  • Purpose: The sentinel lymph node is defined as the first draining node from a primary tumor and reflects the histologic feature of the remainder of the lymphatic basin status. The aim of this study was to evaluate the usefulness of lymphoscintigraphy and intraoperative radioguided gamma probe for identification and removal of sentinel lymph node in breast cancer. Materials and Methods: Lymphoscintigraphy was performed preoperatively in 15 patients with biopsy proven primary breast cancer. Tc-99m antimony sulfide colloid was injected intradermally at four points around the tumor. Imaging acquisition included dynamic imaging, followed by early and late static images at 2 hours. The sentinel lymph node criteria on lymphoscintigraphy is the first node of the highest uptake in early and late static images. We tagged the node emitting the highest activity both in vivo and ex vivo. Histologic study for sentinel and axillary lymph node investigation was done by Hematoxylin-Eosin staining. Results: On lymphoscintigraphy, three of 15 patients had clear lymphatic vessels in dynamic images, and 11 of 15 patients showed sentinel lymph node in early static image and three in late static 2 hours image. Mean detection time of sentinel lymph node on lymphoscintigraphy was $33.5{\pm}48.4$ minutes. The sentinel lymph node localization and removal by lymphoscintigraphy and intraoperative gamma probe were successful in 14 of 15 patients (detection rate: 93.3%). On lymphoscintigraphy, 14 of 15 patients showed $2.47{\pm}2.00$ sentinel lymph nodes. On intraoperative gamma probe, $2.36{\pm}1.96$ sentinel lymph nodes were detected. In 7 patients with positive results of sentinel lymph node metastasis, 5 patients showed positive results of axillary lymph node (sensitivity: 72%) but two did not. In 7 patients with negative results of sentinel lymph node metastasis, all axillary nodes were free of disease (specificity: 100%). Conclusion: Sentinel lymph node biopsy with lymphoscintigraphy and intraoperative gamma probe is a reliable method to predict axillary lymph node metastasis in breast cancer, and unnecessary axillary lymph node dissection can be avoided.

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Risk Assessment of Dermatolymphangioadenitis by Lymphoscintigraphy in Patients with Lower Extremity Lymphedema (하지림프부종 환자에서 림프신티그라피를 이용한 피부림프선염 위험도 평가)

  • Choi, Joon-Young;Hwang, Ji-Hye;Park, Jung-Mi;Lee, Kyung-Han;Kim, Sang-Eun;Kim, Dong-Ik;Lee, Byung-Boong;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.33 no.2
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    • pp.143-151
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    • 1999
  • Purpose: Dermatolymphangioadenitis (DLA) is a common and serious complication of lymphedema which deteriorates lymphatic function. The purpose of this study was to assess the risk of DLA by lymphos-cintigraphy in patients with lower extremity lymphedema. Materials and Methods: The subjects were 59 edematous lower extremities of 50 patients without previous episode of DLA and 12 lower extremities of 6 controls. Whole body images were acquired 1 min and 2 hr after subcutaneous injection of 37 MBq of Tc-99m-antimony sulfide colloid into interdigital spaces of both feet before therapy for lymphedema. The lymphosintigraphic and clinical variables were compared between groups with or without occurrence of DLA during clinical follow up. Results: There were 20 episodes of DLA in 12 extremities during clinical follow-up (19 :6 months). On univariate analysis, there were significant differences in ilioinguinal lymph node uptake, uptake pattern of main lymphatic vessel, clinical stage and therapy compliance between the two groups. After multivariate analysis, only the uptake pattern of main lymphatic vessel and therapy compliance fore confirmed to be independent variables. In other words, non-visualized main lymphatic vessel and poor compliance to therapy were more frequent in extremities with subsequent occurrence of DLA. Conclusion: Lymphoscintigraphy can be used to predict the risk of DLA and may thus be helpful for determining the initial therapeutic plan in patients with lower extremity lymphedema.

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Development of Energy Harvesting Hybrid system consisted of Electrochromic Device and Dye-Sensitized Solar Cell using Nano Particle Deposition System (나노 입자 적층 시스템(NPDS)을 이용한 염료 감응 태양전지 - 전기 변색 통합 소자 및 에너지 하베스팅 시스템에 대한 연구)

  • Kim, Kwangmin;Kim, Hyungsub;Choi, Dahyun;Lee, Minji;Park, Yunchan;Chu, Wonshik;Chun, Dooman;Lee, Caroline Sunyong
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.2
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    • pp.65-71
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    • 2016
  • In this study, Antimony Tin Oxide (ATO) ion storage layer and $TiO_2$ working electrode were fabricated using Nano Particle Deposition System. NPDS is the cutting-edge technology among the dry deposition methods. Accelerated particles are deposited on the substrate through the nozzle using NPDS. The thicknesses for coated layers were measured and layer's morphology was acquired using SEM. The fabricated electrochromic cell's transmittance was measured using UV-Visible spectrometer and power source at 630 nm. As a result, the integrated electrochromic/DSSC hybrid system was successfully fabricated as an energy harvesting system. The fabricated electrochromic cell was self-operated using DSSC as a power source. In conclusion, the electrochromic cell was operated for 500 cycles, with 49% of maximum transmittance change. Also the photovoltaic efficiency for DSSC was measured to be 2.55% while the electrochromic cell on the integrated system had resulted in 26% of maximum transmittance change.

Comparison of Color-developing Methods for Phosphorus Analysis in Various Extractants for Soil Phosphorus (몇가지 토양인산(土壤燐酸) 추출용액(抽出溶液)의 인산(燐酸) 발색방법(發色方法) 비교(比較))

  • Yoon, Jung-Hui;Park, Baeg-Gyoon;Hwang, Ki-Sung
    • Korean Journal of Soil Science and Fertilizer
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    • v.31 no.2
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    • pp.114-119
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    • 1998
  • Intensity and stability of the blue color of phospho-molybdate complex in P analysis are known to be influenced by the matrix, reducing regent and acidity of the extractants. Objective of this research was to compare the efficiency of the color-developing reagents for P concentrations in distilled water and extracts of Lancaster, Mehlich II, and Mehlich III methods. Efficiencies on which to base this study were evaluated by the optimum ranges of P, reproducibility of calibration curve and stability of the developed color. Color-developing reagents employed were ammonium molybdate-1,2,4- aminonaphtholsulfonic acid (ANS), ammonium molybdate-ascorbic acid-bismuth subcarbonate (AB), and ammonium molybdate-ascorbic acid-antimony potassium tartarate (AA). The ANS revealed the lowest sensitivity but the widest ranges for P concentrations in color development. On the other hand, the AA bore the narrowest color-developing ranges and its sensitivity was similar to AB. However, at P concentrations lower than $0.5mg\;L^{-1}$, AA was more sensitive than AB. Based on the data on the ranges of calibration curve, stability of color and reproducibility of analytical data. AA reagent was considered to be suitable for the determination of P in distilled water and AB reagent was practically recommendable for soil P analysis in extracts by Lancaster, Mehlich II, and Mehlich III procedures.

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