• Title/Summary/Keyword: preparation process

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Preparation of WC Powders by SHS Process in the Presence of Alkali Salts (자전연소합성법에서의 알칼리염을 이용한 WC 분말의 제조)

  • Won, Hyung-Il;Nersisyan, Hayk;Won, Chang-Whan
    • Journal of the Korean Ceramic Society
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    • v.44 no.3 s.298
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    • pp.152-156
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    • 2007
  • Tungsten carbide powder was synthesized by SHS (self-propagating high-temperature synthesis). Except $WO_{3}$, each concentration of raw material ($WO_{3},\;Mg,\;NaCl,\;Na_{2}CO_{3},\;C$) was investigated. Final product was characterized by XRD and SEM. X-ray data demonstrated that the $NaCl+Na_{2}CO_{3}$ combined mixture has superiority in the WC formation process. Single phase and submicrometer WC powder was synthesized at the temperature below $1600^{\circ}C$. The role of sodium salts in combustion process was discussed, and chemical mechanism of WC formation was proposed. WC powder prepared by salt-assisted combustion synthesis has a size $0.2{\sim}3\;{\mu}m$ and low agglomeration degree.

Automated Inspection System Using Image Processing Technology for Automotive Components (영상처리 기법을 이용한 자동차부품의 자동검사시스템 개발)

  • Park, Jung-Kee;Jung, Won
    • Journal of Korea Society of Industrial Information Systems
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    • v.4 no.3
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    • pp.71-78
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    • 1999
  • This paper presents an integrated and automated inspection system using image processing technology for the automotive engine assembly process. The system make it possible for the inspected data to be entered directly from the machine vision into the statistical process control system. Such direct entry enables the prompt preparation of corrective actions against process problems. An IVP-150 machine vision board is installed within the PC for image processing, and a template matching technology is implemented to precisely verify quality factors. The developed system showed robustness to the problems of noise, distortion, and orientation.

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Preparation of Mulberry Leaves Tea and Its Quality Characteristics (뽕잎차의 제조와 그 품질 특성)

  • Kim, Dong-Chung;In, Man-Jin;Chae, Hee-Jeong
    • Journal of Applied Biological Chemistry
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    • v.53 no.1
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    • pp.56-59
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    • 2010
  • An optimal manufacturing process was established for the mass-production of mulberry leaves tea. The produced tea contained abundant dietary fibers, $\beta$-carotenes, and calcium. Also the polyphenol content and antioxidant activity of mulberry leaves tea were higher than those of simply dried mulberry leaves. These results imply that this tea manufacturing process is effective to utilize the useful components of mulberry leaves.

A Study on the Contents Production for a Clothing Design Analysis - Focused on the Image Medium of Chinese Historical Background - (의상디자인 분석을 위한 콘텐츠 제작에 관한 연구 - 중국역사배경 영상매체를 중심으로 -)

  • Yoon, Hae-Gyung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.8 no.2
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    • pp.61-71
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    • 2006
  • The purpose of this study is to present a contents production process for costume design analysis by take advantage of the image media of Chinese historical backgrounds. The production process of contents for lectures on fashion design analysis can be summarized as follows: The contents for the design analysis of Chinese costumes can be divided into major media and supplementary media. Major media can be completed through the processes including the selection of Chinese historical backgrounds. images and media (video, DVD title or VOD), verification of image capture parts, image captures, and applications of PPT files. Supplementary media consist of production of analysis materials for each item and TPO, report preparation methods and discussions, and printed matters to be used at the stage of image comparison and verification. This way, a process applicable to the design analysis of Chinese costumes can be presented.

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Preparation of YBCO thin films by MOD-TFA process (MOD-TFA법에 의한 YBCO 박막의 제조)

  • 김영국;유재무;고재웅;허순영;이동철
    • Progress in Superconductivity
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    • v.5 no.1
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    • pp.80-83
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    • 2003
  • Superconducting YBCO thin films are fabricated on single-crystalline substrates by Metallo-organic Depostion process employing Trifluoroacetic acid as a chelating agent (MOD-TFA). (100)-oriented single crystalline LaAlO$_3$ substrates were employed to grow superconducting film with high crystallinity. The fully processed YBCO thin films were characterized with XRD, SEM, EDS, etc. The microstructures of YBCO thin films show labyrinth-like patterns. The origin of this microstructure was delineated by compositional inhomogeneity during the MOD process and it was shown that the microstructure may be modified by additives. In this work, effects of additives on the microstructures and electrical properties of YBCO thin films have been investigated.

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리보핵산 관련물질을 함유한 Yeast Extracts 제조에 Streptomyces faecalis MSF 배양액의 이용

  • 임억규
    • Microbiology and Biotechnology Letters
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    • v.25 no.5
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    • pp.512-519
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    • 1997
  • RNA accumulating strain of Torulopsis versatilis MT-1 was cultured in molasses medium for higher contents of RNA in cell. Yeast cells were harvested at logarithmic phase on synchronous culture. Yield of cells on dry base to input sugar was 59.5%. Crude protein content was 55.1% in cell. RNA content was 13.9%. Some problems found in the process for the preparation of yeast extracts were improved by the addition of culture broth of Streptomyces faecalis MSF which secrete RNase (5' nuclease and 5' adenylic acid deaminase). When the culture broth of S. faecalis MSF was added in autolysis process 46% of RNA in cell was converted to I and G(5' inosinic acid and 5' guanylic acid) in extract. By addition of 3-7% culture broth of S.faecalis MSF in autolysis or enzymolysis process at the start or early stage, RNA in extract was converted easily to I and G and protein in cells was easily extracted and hydrolyzed to amino acid. Taste of those yeast extracts was delicious. The yeasty smell in yeast extracts was removed. And cell debris was easily removed from extract.

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Effects of Nucleating Agents on Preparation of Polypropylene Hollow Fiber Membranes by Melt Spinning Process

  • Kim, Bong-Tae;Kigook Song;Kim, Sung-Soo
    • Macromolecular Research
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    • v.10 no.2
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    • pp.127-134
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    • 2002
  • Microporous polypropylene hollow fiber membrane was fabricated from isotactic polypropylene-soybean oil system by melt spinning process. Addition of nucleating agent accelerated the crystallization rate and elevated the crystallization temperature. Nucleating agent increased the number of nuclei and spherulites, which offered more inter-spherulitic amorphous sites for stretching. Benzoic acid, adipic acid, and dibenzylidene sorbitol were selected as nucleating agents, and their characteristics and effects were investigated by thermal and optical analyses. Spherulite growth and micropore formation characteristics were correlated with the kind of nucleating agent. Benzoic acid and adipic acid showed the remarkable nucleating effect, while dibenzylidene sorbitol was less effective than those. Nucleating agents also helped the sample have uniform microporous structure. Increase of nucleating agent composition enhanced the nucleation effect to some extent. Nucleating agents played very important roles in enhancing the membrane porosity and water flux.

Application of Dynamic Simulation for Efficient Filler-Loading in Papermaking System (제지 공정의 효율적인 충전제 투입에 대한 동적 시뮬레이션 적용)

  • 함충현;윤혜정
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.3
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    • pp.1-12
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    • 2003
  • The complexity of the papermaking system accelerates interactions between a large number of variables involved. The process operation, therefore, is subject to frequent perturbations by disturbance. Dynamic modelling is a useful tool for characterizing the transient behavior and selecting the best control strategies to reject disturbances. In this study we developed a dynamic simulation model of a fine paper production process, which consists of stock preparation, wire sections, white water circulations, and broke system. It focused on dynamic simulation in its role for developing control strategies and studying control loop dynamics related to filler loading for ash control. The results emphasized the importance of filler-loading position and length of control loop for rapid ash control and process stabilization.

Preparation of $PMMA-co-MMA/TiO_2$ Composite Film by Sol-Gel Process and Its Application to OTFTs as a Gate Insulator

  • Park, Jae-Hoon;Kim, Hyun-Suck;Bong, Kang-Wook;June, Bong;Choi, Hyoung-Jin;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1146-1149
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    • 2006
  • In this study, nanocomposite layer composed of PMMA-co-MMA and $TiO_2$ was prepared by sol-gel process using TTIP as a precursor and was utilized as a gate insulator of OTFTs. The composite insulator provides the lower threshold voltage and the enhanced sub threshold slope of OTFTs mainly due to its higher dielectric constant than that of the bare PMMA-co-MMA. Consequently, it is demonstrated that the sol-gel process can open an interesting direction for the fabrication of high-performance OTFTs, and contribute for OTFTs to be feasible for real applications.

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Development of an Isolable Active Ester, Diethyl Thiophosphoryl [(Z)-(2-Aminothiazol-4-yl)-2-(Methoxyimino)acetate (DAMA) for the Synthesis of Cefotaxime

  • Yoon, Man-Young;Lee, Hee-Bong;Shin, Hyun-Ik
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.407-410
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    • 2011
  • An isolable activated ester, diethyl thiophosphoryl [(Z)-(2-aminothiazol-4-yl)-2-(methoxyimino)acetate (9a, DAMA) was prepared in high purity, which was at least stable for 7 d at $25^{\circ}C$ and 6 months at $5^{\circ}C$. Its reaction with 7-ACA (4) in the presence of tributylamine in i-PrOH provided cefotaxime (1) of high purity in good yield. Preparation of DAMA and its reaction with 7-ACA (4) to 1 was performed in one-pot manner, respectively with minimal unit operations of stirring and filtration.