• Title/Summary/Keyword: high-purity

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A Study on the Characteristics of Electro-Polishing and Utility Materials for Gas Transitting (Gas 이송용 Utility Materials의 전해연마 특성에 관한 연구)

  • An, Se-Won;Lee, Jong-Hyung;Park, Moo-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.3
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    • pp.52-57
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    • 2004
  • Many kinds of gases, such as erosion gas, dilution gas, and toxic gas have been used in manufacturing process of LCD at semiconductor. In order to increase accumulation rate of manufacturing process, high degree of purity in these gases and minimized metalllic dust are required. All wetted stainless steel surface must be 316L electro-polished with $0254{\mu}m$ in average. Based on the AES analysis, Cr/Fe 11 and $Cr_2O_3$ thickness $25{\AA}$ are measured Molybdenum and silicon contaminants which is characteristic of stainless steel and oxygen were found on the surface.

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Purification of YPTP1 with Immobilized Phosphonomethylphenylalanine-Containing Peptide as an Affinity Ligand

  • Han, Jun-Pil;Kwon, Mi-Yun;Cho, Hyeong-Jin
    • BMB Reports
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    • v.31 no.2
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    • pp.135-138
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    • 1998
  • A previous study on a yeast protein tyrosine phosphatase, YPTP1, using synthetic phosphotyrosine-containing peptides with various sequences as substrates revealed that DADEpYDA exhibits high affinity ($K_m=4{\mu}M$) toward the enzyme. A modified version of this peptide, GDADEpmFDA, immobilized on a resin, was used in this study as an affinity ligand for the purification of YPTP1. Phosphonomethyl-phenylalanine (pmF) was used as a nonhydrolyzable analog of the phosphotyrosine (pY) residue, with properties similar to pY. A protected form of pmF, $Fmoc-pmF(^{t}Bu)_{2}-OH$, was chemically synthesized and introduced during solid-phase peptide sythesis. YPTP1 was onrexpressed in an E. coli strain carrying a plasmid pT7-7-ptpl. Affinity chromatography of the crude lysate afforded PTPI (39 kDa) of about 50% purity.

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Chalcogenide Ge-Sb-Se Optical and Crystallization Characteristics for Basic a Planning Aspheric Lens (비구면렌즈 설계를 위한 칼코게나이드 Ge-Sb-Se 광학계 및 결정화 특성 연구)

  • Myung, Tae Sik;Ko, Jun Bin
    • Korean Journal of Materials Research
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    • v.26 no.11
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    • pp.598-603
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    • 2016
  • The recent development of electro-optic devices and anticorrosion media has led to the necessity to investigate infrared optical systems with solid-solid interfaces of materials that often have the characteristic of amorphousness. One of the most promising classes of materials for those purposes seems to be the chalcogenide glasses. Chalcogenide glasses, based on the Ge-Sb-Se system, have drawn a great deal of attention because of their use in preparing optical lenses and transparent fibers in the range of 3~12 um. In this study, amorphous Ge-Sb-Se chalcogenide for application in an infrared optical product design and manufacture was prepared by a standard melt-quenching technique. The results of the structural, optical and surface roughness analysis of high purity Ge-Sb-Se chalcogenide glasses are reported after various annealing processes.

Recent Progress of Membrane Technology and its New Application for Water Treatment

  • Hiroyuki, Yamamura;Yoshinari, Fusaoka;Masaru, Kurihara
    • Proceedings of the Membrane Society of Korea Conference
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    • 1998.06a
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    • pp.81-94
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    • 1998
  • Nowadays, membrane separation such as reverse osmosis (RO) and ultrafiltration (UF) play an important role in the industrial separation technology. Among desalination technologies available today, reverse osmosis is usually the most economical process for wide range of water salinity. Main applications include production of high purity water, desalination of seawater and brackish water for a drinking water supply, treatment of waste water for environmental protection, and recovery of precious materials from industrial waste water. In this paper, we will mention membrane performance and these practical use focused on reverse osmosis membranes and ultrafiltration membranes recently developed by Toray.

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The Design of 3KW virtual Solar Cell with using boost converter (부스트 컨버터를 이용한 3Kw 태양전지 어레이 가상구현 설계)

  • Oh B.W.;Lee S.Y.;Lee B.I.;Jung B.H.;Choe G.H.
    • Proceedings of the KIPE Conference
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    • 2003.07b
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    • pp.929-932
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    • 2003
  • Recently, energy Problem has become more important thing than that of past years. Therefore, researchers in many countries are trying to find the solution for removing energy Problem. One of all is the power generation with using the photovoltaic system. Because this system has some advantage, like purity and infinity. However, there are some problems to generate electrical power with using photovoltaic system. That problems, taking up a very big space and taking financial worries, come into existence. So it is inevitable to make the visual implement equipment for doing repetition experiment and solving this problems. In this paper, Boost converter are analyzed and simulated to make high power PV virtual implement system as input source instead of using transformer.

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A Comparison of Separated and Combined Winding Concepts for Bearingless Centrifugal Pumps

  • Raggl, Klaus;Nussbaumer, Thomas;Kolar, Johann W.
    • Journal of Power Electronics
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    • v.9 no.2
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    • pp.243-258
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    • 2009
  • Bearingless centrifugal pump systems are employed in the semiconductor, pharmaceutical and medical industries due to their facility for pumping high purity fluids without particle contamination. Two types of forces have to be generated by the stator units, namely bearing forces for achieving magnetic levitation, and drive forces for producing the needed pump torque. The generation of these forces requires bearing and drive windings, which can be realized as separate bearing and drive coils or as identical, combined coils on the stator claws. In this paper, a detailed comparison between these two winding concepts is undertaken, whereby the copper losses, the power electronics losses, and the achievable pump output pressure are evaluated for both concepts. For each criterion a ratio of improvement is calculated analytically which allows evaluation of the performance of the two winding concepts for any given pump operating point and design. Finally, also practical features such as control complexity, cabling effort and manufacturability are discussed and measurements on prototype systems are carried out to validate the considerations.

Chromatographic Separation of Maltopentaose from Maltooligosaccharides

  • Lee, Jae-Wook;Kwon, Tae-Ouk;Moon, Il-Shik
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.1
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    • pp.47-53
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    • 2003
  • An experimental study on the chromatographic separation of maltopentaose from a mixture, including glucose, maltose, maltotriose, and maltopentaose, was carried out in a nonionic polymeric sorbent column while varying the operating conditions, such as the solution pH, buffer contents, and isopropyl alcohol (1PA) concentration. Unlike the pH and buffer contents, the IPA concentration had a Significant impact on the single component chromatograms for maltopentaose. The retention times of the maltooligosaccharides with the nonionic polymeric sorbent Sp207 were in the following order: glucose < maltose < maltotriose < maltopentaose. From the experimental binary, ternary, and quaternary chromatograms, gradient chromatographic separation with a changing IPA concentration as a function of time was required to obtain high-purity maltopentaose and reduce the elution time.

Fundamental Study on the CO2 gas Fixation Method using the Cement-Paste Solution's Calcium ion (시멘트 페이스트 수용액의 칼슘 이온을 이용한 CO2 가스 고정화에 관한 기초적 연구)

  • Kwack, Jae-Seok;Kang, Chang-Soo;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.71-72
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    • 2012
  • The purpose of this study is not only fixation of carbon dioxide using the cement-Paste solution's calcium ion by wet carbonating reaction but also quantitatively evaluate the possibility of storage technology of Carbon dioxide. wet carbonation is reaction of CO2 injection by CO2 reactor. As a result of experiment, the carbon dioxide is fixed, and high-purity Calcium Carbonate is eluted.

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The Study on the Solidification of V-Section and Finned Casting by Use of Pure Aluminum (순(純) 알루미늄 V형(型) 및 Finned Casting의 응고(凝固)에 관(關)한 연구(硏究))

  • Kim, M.H.;Kang, C.S.;Kim, D.O.;Jeong, J.Y.
    • Journal of Korea Foundry Society
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    • v.7 no.1
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    • pp.28-37
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    • 1987
  • The progression of the solidification wave front in V-section and finned casting was studied by use of the pour-out test, employed with high. Purity aluminum. The results obtained were as follows; a) The shape of solidification wave front at the inside and outside corners did not change according to solidification time, but it changes according to the corner angles at a given molding and melting condition. b) The cooling fin effect could be repserented as functions of solidification time and fin sise, and this result could be applied to enhance the accuracy of the section modulus method in the design of T and V section.

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Effects of Process and Casting Variables on the Results of Degassing AC4C Aluminum Alloy Melt by Using Rotary Degasser (공정 및 주조 변수의 AC4C 알루미늄 합금 용탕의 로터리 degasser를 이용한 탈가스 처리 결과에 미치는 영향)

  • Lee, Ki-Joon;Kwon, Hae-Wook
    • Journal of Korea Foundry Society
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    • v.20 no.6
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    • pp.407-418
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    • 2000
  • The effect of various factors on the results of degassing of AC4C aluminum alloy melt by using rotary degasser were investigated. The difference between the effects of nitrogen gases of commercial pure and high purity grades on the degassing results was not significant. The optimum degassing condition was obtained. The effect of holding and degassing temperature was not significant, either. The result of degassing was deteriorated by the modification treatment of eutectic silicon, meanwhile improved by the grain refining. The effect of the latter was stronger than that of the former when the melt was treated simultaneously. The volume fractions of hydrogen porosity of the castings obtained from the molds with water moisture such as natural and green sand molds were much higher than those from the molds without that such as pep-set and $CO_2$ molds.

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