• 제목/요약/키워드: chemical quality

검색결과 4,732건 처리시간 0.036초

한국 쌀과 일본 쌀의 물리화학적 특성 연구 (I) NIR을 사용한 한국 쌀과 일본 쌀의 품질 비교 (Comparison of Korean and Japanese Rice Cultivars in Terms of Physicochemical Properties (I) The Comparison of Korean and Japanese Rice by NIR and Chemical Analysis)

  • 김혁일
    • 동아시아식생활학회지
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    • 제14권2호
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    • pp.135-144
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    • 2004
  • A total of 40 Korean and Japanese rice varieties were evaluated for their main chemical components, physical properties, cooking quality, pasting properties, and instrumental measurements. Based on their quality evaluations, it was concluded that Korean and Japanese rice varieties were not significantly different in the basic components of NIR (Near Infra Red) data and the chemical analysis from the uncooked brown and milled rices. Korean rice had a little bit higher protein and amylose contents but much lower fat acidity than those of Japanese rice from the chemical analysis. From all the data of three different kinds of NIR methods, Korean and Japanese milled rice were very similar except the taste score. Japanese rice showed a slightly higher taste score, a little bit higher lightness and whiteness, but lower yellowness and redness than Korean one. From all those data of NIR and the chemical analysis, Korean and Japanese rices had very similar components except the fat content.

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Advances in Chemical Process Control and Operation -A view experienced in joint university-industry projects

  • Ohshima, Masahiro
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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    • pp.1.2-6
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    • 1994
  • A state or the arts in Japanese chemical process control is reviewed based on experience in applying advanced process control schemes to several industrial chemical processes. The applications validate model predictive control (MPC), the most popular advanced control scheme in the process control community, as, indeed, a powerful and practical control algorithm. However, at the same time, it is elucidated that MPC can solve only the control algorithm part of the problem and one needs chemical and systems engineering aspects to solve the entire problem. By illustrating several industrial process control problems, the need for chemical engineering aspects as well as the future direction for process control are addressed, especially in light or current attitudes toward product quality.

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Bulk건조에서 주맥건조방법이 잎담배 이화학성에 미치는 영향 (Effect of Stem Drying Method during Curing Process on Physico-chemical Properties in Bulk Cured Leaves)

  • 이철환;이병철;진정의
    • 한국연초학회지
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    • 제22권2호
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    • pp.133-137
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    • 2000
  • The bulk curing experiment to improve the quality of flue-cured leaves were carried out to evaluate relationship between the modified(3 step-up) drying and conventional drying method in bulk curing process. Modified drying method was somewhat higher values in yellowing color index of cured leaves, and less brittle than those in conventional drying program. As to the chemical properties, there was no difference in chemical component levels in cured leaves between the modified and the conventional methods, while the major chemical compounds in relation to aromatic essential oil of cured leaves showed mostly higher level in the modified method than that in conventional drying method. Additionally 3 step-up drying method increased the tobacco quality by 2 % in price per kg compared with conventional drying method.

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화학무삼투백색자견이 사조에 미치는 영향 (Relationship silk reelability with nonpermeative cocoon cooking after chemical treatment)

  • 최병희;유시환
    • 한국잠사곤충학회지
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    • 제5권
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    • pp.43-46
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    • 1965
  • 본 연구는 우리나라의 원료견을 화학적으로 처리하여 무삼투 상색자견을 함으로서 생사소출량을 증대시키는 데 목적으로 하였든 바 다음 결과를 얻었다. 1. 본 연구목적을 달성하기 위하여 Serisol 해서촉진제를 창안하였다. 2. 본 해서촉진제로 생사량비율에서 0.4%의 증가를 보았다. 3. 본제는 무삼투자견을 효과적으로 하였다. 4. 본제를 사용한 생사의 마디성적은 좋은 결과이었다. 5. 본제를 사용한 생사의 기타 생사품위에 악영향이 없었다. 6. 본제는 2000배로 희석할 때 가장 그 성적이 좋았다.

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Effectiveness of external agents in polluted sedimentary area

  • Alam, Md. Mahabub;Haque, Md. Niamul;Cho, Daechul;Kwon, Sung-Hyun
    • Environmental Engineering Research
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    • 제21권1호
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    • pp.52-57
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    • 2016
  • Sediment is a useful natural source but deteriorated continually by anthropogenic and industrial sources. Therefore, it is imperative to search a suitable method for improving or restoring sediment quality. Sediment has been tested to identify the effects of some external agents on a polluted area for 28 days. Chemical analysis and total viable counts (TVC) test have been conducted for 4 days interval to assess their performance. The analyses of chemical oxygen demand (COD), acid volatile sulfide (AVS), total phosphorous (T-P), total nitrogen (T-N) indicate that the chemical agents was more efficient to improve sediment quality whereas the microbial agent was more efficient for nutrient releasing from sediment. Oxygen releasing property of the chemical agent was thought to be providing with more congenial environment for the higher growth of the bacterial community than the direct application of microbial agents.

굴곡 융착면을 이용한 고밀도폴리에틸렌 관의 버트 융착 공정에서의 열유체 거동 수치모사 (Numerical Simulation of Heat and Flow Behaviors in Butt-fusion Welding Process of HDPE Pipes with Curved Fusion Surface)

  • 유재현;최선웅;안경현;오주석
    • Korean Chemical Engineering Research
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    • 제55권4호
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    • pp.561-566
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    • 2017
  • 폴리머 재질의 관을 융착 시키기 위해서는 버트 융착 공정을 거치는데, 최근 융착면에 굴곡을 주어 융착 강도를 높이고자 하는 시도가 있었다. 본 연구에서는 융착면의 굴곡이 폴리머의 열유체 거동 및 융착 강도에 어떠한 영향을 미칠 것인지 2차원 축대칭 평면에서 유한요소법을 사용하여 살펴보았으며, 고밀도폴리에틸렌 관을 대상으로 하였다. 열유화 단계에서 융착면의 형상을 따라 굴곡진 상경계면이 나타남을 확인할 수 있었다. 접합 단계에서는 굴곡진 상경계면과 융착면 사이에서의 멜트의 압착 흐름이 나타남을 확인할 수 있었으며, 굴곡융착부의 낮은 전단율은 관의 축과 수직 방향 배향을 완화시켜 융착부 강도 향상에 도움을 줄 수 있을 것으로 예상된다.

Graphene Synthesized by Plasma Enhanced Chemical Vapor Deposition at Low-Temperature

  • Ma, Yifei;Kim, Dae-Kyoung;Xin, Guoqing;Chae, Hee-Yeop
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.248-248
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    • 2012
  • Synthesis graphene on Cu substrate by plasma-enhanced chemical vapor deposition (PE-CVD) is investigated and its quality's affection factors are discussed in this work. Compared with the graphene synthesized at high temperature in chemical vapor deposition (CVD), the low-temperature graphene film by PE-CVD has relatively low quality with many defects. However, the advantage of low-temperature is also obvious that low melting point materials will be available to synthesize graphene as substrate. In this study, the temperature will be kept constant in $400^{\circ}C$ and the graphene was grown in plasma environment with changing the plasma power, the flow rate of precursors, and the distance between plasma generator coil and substrates. Then, we investigate the effect of temperature and the influence of process variables to graphene film's quality and characterize the film properties with Raman spectroscopy and sheet resistance and optical emission spectroscopy.

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Stability of Coated Green Phosphors for Enhancing Picture Quality of PDP

  • Han, B.Y.;Kim, J.H.;Yoo, J.S.;Kim, Y.K.;Hur, Y.K.;Choi, C.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.942-945
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    • 2006
  • The picture quality of a plasma display panel is very sensitive to the phosphor characteristics such as luminescence, decay time, surface properties, and even longevity of phosphor material in itself. In our previous work, the discharging characteristics in green cell of PDP were demonstrated to be enhanced by coating $Zn_2SiO_4:Mn^{2+}$ phosphors with positively charged metal oxide such as MgO. Here, $Zn_2SiO_4:Mn^{2+}$ phosphors were coated by various metal oxides for examining the coating effect on the picture quality. Specially, longevity while fabricating the panel was investigated for panel application in this work. Also the effects of ion and electron bombardment on the phosphor surface will be discussed in this work.

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