• Title/Summary/Keyword: Chemical processing

검색결과 1,898건 처리시간 0.028초

XPS STUDY ON SN-DOPED DLC FILMS PREPARED BY RF PLASMA-ENHANCED CVD

  • Inoue, Y.;Komoguchi, T.;Nakata, H.;Takai, O.
    • 한국표면공학회지
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    • 제29권5호
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    • pp.519-524
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    • 1996
  • We synthesized semiconducting Sn-doped diamondlike carbon films by rf plasma-enhanced chemical vapor deposition using an organotin compound as a dopung gas source. XPS quan-titative analysis for the deposited films after 60 s argon ion etching revealed that Sn concen-tration increased with the partial pressure of the organotin compound in the reactant gas. In C 1s spectra, there was a component due to C-Su bond which had a negative chemical shift. C 1s spectra also indicated that the deposited films were relatively $sp^2$ rich. The chemical shift of the Sn-C bond in Sn $3d_{5/2}$ spectra was about +1.7 eV. The electrical resistivity and the optical transmittance were also investigated.

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케미컬 밀링을 이용한 실린더 경량화 연구 (A Study on the Light Cylinder Using Chemical Milling)

  • 유준태;윤종훈;장영순;이영무;강석봉;이종웅
    • 대한기계학회논문집A
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    • 제30권4호
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    • pp.451-456
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    • 2006
  • The process for reducing the weight of the structure is chiefly performed by the machine processing. But, increasing the weight for strength of welding zone and geometrical defect are occurred in machine processing. In this study, chemical milling is applied to reduce the weight of the cylinder. Before chemical milling is applied to the cylinder, specimen testing is performed. After the specimen testing, NaOH 15% is selected to perform the chemical milling. After the chemical milling, the velocity of reagent is 0.0016 mm/min and the thickness of cylinder is about 2.4 mm after chemical milling.

Dynamic simulation of squeezing flow of ER fluids using parallel processing

  • Kim, Do-Hoon;Chu, Sang-Hyon;Ahn, Kyung-Hyun;Lee, Seung-Jong
    • Korea-Australia Rheology Journal
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    • 제11권3호
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    • pp.233-240
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    • 1999
  • In order to understand the flow behavior of Electrorheological (ER) fluid, dynamic simulation has been intensively performed for the last decade. When the shear flow is applied, it is easy to carry out the simulation with relatively small number of particles because of the periodic boundary condition. For the squeezing flow, however, it is not easy to apply the periodic boundary condition, and the number of particles needs to be increased to simulate the ER system more realistically. For this reason, the simulation of ER fluid under squeezing flow has been mostly performed with some representative chains or with the approximation that severely restricts the flow geometry to reduce the computational load. In this study, Message Passing Interface (MPI), which is one of the most widely-used parallel processing techniques, has been employed in a dynamic simulation of ER fluid under squeezing flow. As the number of particles used in the simulation could be increased significantly, full domain between the electrodes has been covered. The numerical treatment or the approximation used to reduce the computational load has been evaluated for its validity, and was found to be quite effective. As the number of particles is increased, the fluctuation of the normal stress becomes diminished and the prediction in general was found to be qualitatively In good agreement with the experimental results.

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Preparation of Polymer/Drug Nano- and Micro-Particles by Electrospraying

  • Lee, Jong-Hwi;Park, Chul-Ho;Kim, Min-Young;Yoo, Ji-Youn;Kim, Ki-Hyun;Lee, Jong-Chan
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.217-217
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    • 2006
  • The surface energy control capability of electrohydrodynamic force provides electrospraying with various potential advantages such as simple particle size control, mono-dispersity, high recovery, and mild processing conditions. Herein, the one step nano-encapsulation of protein drugs using electrospraying was developed. The major processing parameters such as the conductivity of spraying liquids, flow rate, the distance between electric potentials, etc were examined to obtain the maximum efficiency. The recovery of particles was found relatively high as could be conjectured based on the principle of electrospraying. When organic solvents were employed, the processing windows of electrospraying were relatively narrow than water systems. Efficient nano-encapsulation of BSA with polymers was conveniently achieved using electrospraying at above 12 kV.

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연산별 황색종 가공엽의 화학성분 함량 및 편차 분석 (Analysis of Contents and Deviations of Chemical Constituents of flue-cured leaf Tobacco from 1997 to 2001 Crop Years)

  • 김상범;정기택;조수헌;김용규
    • 한국연초학회지
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    • 제25권1호
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    • pp.20-26
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    • 2003
  • To investigate the effects of reduction of leaf processing factories on the uniformity of processed leaf quality, the contents and their C.V.(Coefficient of Variation) of chemical constituents of flue-cured leaf tobacco produced from 1997 to 2001 and processed at various factories were analysed. The average leaf chemical contents of 12 grades for 5 years ranged as follows ; nicotine 2.00∼0.85%. total sugar 10.7∼16.9%, total nitrogen 2.36∼2.78%, crude ash 14.6∼15.6% and chlorine 0.50∼0.75%. The variations of chemical contents among crop years was higher in total sugar content while lower in crude ash content. The C.V. of chemical content in same grade leaves was higher in chlorine content while lower in total nitrogen and crude ash contents, and the ratio of C.V. among processing factories/C.V. in total population was higher in total sugar content while lower in crude ash content. When the leaves were processed at one factory, the deviations of chemical contents reduced considerably. Particularly, the decreasing effect of deviation was higher in total sugar content.

The Differences in Chemical Composition, Physical Quality Traits and Nutritional Values of Horse Meat as Affected by Various Retail Cut Types

  • Seong, Pil Nam;Park, Kyoung Mi;Kang, Geun Ho;Cho, Soo Hyun;Park, Beom Young;Chae, Hyun Seok;Ba, Hoa Van
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권1호
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    • pp.89-99
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    • 2016
  • The effects of retail cut type on chemical, quality and nutritional characteristics of horse meat were studied. Jeju female breed horses (n = 9) at 32-mo-old were slaughtered and the carcasses at 24 h post-mortem were fabricated into 10 retail cuts including: tender-loin, loin, strip-loin, shoulder-chuck-roll, shoulder-clod, top-round, outside-round, brisket, short-plate-brisket, and shank. The results revealed that all of parameters (chemical, meat quality and nutritional composition) examined significantly (p<0.05) differed between the cuts. The chemical composition range (minimum to maximum) of cuts was found as such: moisture 65.06% to 71.69%; protein 19.07% to 21.28%; collagen 1.40% to 2.45%; fat 2.56% to 12.14% and cholesterol 55.76 to 79.50 mg/100 g. Shoulder-chuck-roll had the highest pH and water-holding capacity, while top-round had the highest cooking loss. Shear force ranged between the cuts from $2.80kg/cm^2$ to $4.98kg/cm^2$. The Cu, Fe, and Zn contents ranged between the cuts from 1.52 mg/kg to 2.75 mg/kg, 21.25 mg/kg to 30.85 mg/kg, and 16.51 mg/kg to 40.42 mg/kg, respectively. Additionally, most of the cuts studied showed favorable polyunsaturated fatty acid/saturated fatty acid, n-3/n-6 and essential amino acid/non-essential amino acid ratios.

인삼의 가공방법에 따른 일반성분 및 Ginsenoside 함량 변화 (Changes of Chemical Compositions and Ginsenoside Contents of Different Root Parts of Ginsengs with Processing Method)

  • 최재을;남기열;이상국;김복용;조황식;황광보
    • 한국약용작물학회지
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    • 제18권2호
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    • pp.118-125
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    • 2010
  • This study was carried out to determine changes in general chemical composition, free sugars, physicochemical properties of extract, and ginsenoside contents depending upon processing methods. Ginseng roots harvested from the same field were employed for the processing into white ginseng (WG), taegeuk ginseng (TG), red ginseng A (RGA, steamed one time), and red ginseng B (RGB, steamed three times). The fat content decreased by increasing duration of treatment and number of steaming treatment. On the other hand, there was no significant variation in contents of ash and carbohydrate depending on processing methods. Contents of sucrose and maltose was higher in Taegeuk and red ginseng than those of white ginseng. Steamed ginseng root (taegeuk and red ginseng root) showed higher amount of water extractable solid than the unsteamed white ginseng, but the variation of crude saponin content was not distinctive depending on processing methods. The contents of total ginsenosides increased by the order of white, taegeuk, red A, and red B root. In summary, chemical composition and total ginsenoside content were different according to part of root and processing methods, thus implies the importance of quality control as well as pharmacological activity of ginseng root.

Soft Solution Processing : Low-Energy Direct Fabrication of Advanced Inorganic Materials

  • Masahiro Yoshimura;한규승;Wojciech Suchanek
    • Bulletin of the Korean Chemical Society
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    • 제20권8호
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    • pp.875-878
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    • 1999
  • A new concept ??soft solution processing?? has been introduced to fabricate advanced solid state materials in an economical, environmentally friendly, and energy and material efficient way. The prepared films show the desired and prospective properties despite of low temperature synthesis and no post-synthesis annealing. Successful examples demonstrate that soft solution processing is capable of preparing advanced materials with planned properties through the easy control of reaction conditions in a suitable aqueous solution in a single synthetic step without huge energy consumption and without any sophisticated equipment.

새로운 피혁폐수 처리제에 관한 연구; I. 새로운 유기 응결제의 개발 (A study on new treatment chemical for leather wastewater; I. Development of new organic coagulant)

  • 정맹준;이철재;한성욱
    • 한국산업융합학회 논문집
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    • 제9권4호
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    • pp.323-330
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    • 2006
  • As the interest in environmental pollution resulting from recent industrial development is converging, wastewater treatment problem of dying processing is one of important pending issue. Usually, flow mediation earth and settling pond etc. of processing plant to handle water or wastewater. Mediation is the wastewater that flowed past settling pond than material of heavy particles, water weight colloid particles that big solids are removed but are suspensibility material settlement exclusion impossible. So, we need flocculation and coagulation action to remove materials from this colloid state. For flocculation and coagulation action chemical agents to add back, addition of chemical agents forms floc of could settle size. That is, shorten the sedimentation time and quality of processing water because promoting sedimentation doing to do fines or suspended solids and colloid can materials large size and also, flocculation to annex efficiency of filtration augment. Therefore, I executed this research to prove that improving organic matter and chromaticity of treated water of processing epochally using organic coagulant informed positive ion co-polymerization superior in color wastewater through this research.

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