• 제목/요약/키워드: Density profile

검색결과 754건 처리시간 0.026초

미세금형 가공을 위한 전기화학식각공정의 유한요소 해석 및 실험 결과 비교

  • 류헌열;임현승;조시형;황병준;이성호;박진구
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.81.2-81.2
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    • 2012
  • To fabricate a metal mold for injection molding, hot-embossing and imprinting process, mechanical machining, electro discharge machining (EDM), electrochemical machining (ECM), laser process and wet etching ($FeCl_3$ process) have been widely used. However it is hard to get precise structure with these processes. Electrochemical etching has been also employed to fabricate a micro structure in metal mold. A through mask electrochemical micro machining (TMEMM) is one of the electrochemical etching processes which can obtain finely precise structure. In this process, many parameters such as current density, process time, temperature of electrolyte and distance between electrodes should be controlled. Therefore, it is difficult to predict the result because it has low reliability and reproducibility. To improve it, we investigated this process numerically and experimentally. To search the relation between processing parameters and the results, we used finite element simulation and the commercial finite element method (FEM) software ANSYS was used to analyze the electric field. In this study, it was supposed that the anodic dissolution process is predicted depending on the current density which is one of major parameters with finite element method. In experiment, we used stainless steel (SS304) substrate with various sized square and circular array patterns as an anode and copper (Cu) plate as a cathode. A mixture of $H_2SO_4$, $H_3PO_4$ and DIW was used as an electrolyte. After electrochemical etching process, we compared the results of experiment and simulation. As a result, we got the current distribution in the electrolyte and line profile of current density of the patterns from simulation. And etching profile and surface morphologies were characterized by 3D-profiler(${\mu}$-surf, Nanofocus, Germany) and FE-SEM(S-4800, Hitachi, Japan) measurement. From comparison of these data, it was confirmed that current distribution and line profile of the patterns from simulation are similar to surface morphology and etching profile of the sample from the process, respectively. Then we concluded that current density is more concentrated at the edge of pattern and the depth of etched area is proportional to current density.

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H-UV 무습수 오프셋 인쇄에서 CMS 적용에 관한 연구 (Study on CMS Application in Hybrid UV Waterless Off-Set Printing)

  • 구철회;조가람
    • 펄프종이기술
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    • 제45권5호
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    • pp.1-13
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    • 2013
  • This study found fit optimum C, M, Y, K solid density and $CIEL^*a^*b^*$ value to paper & ink as well as check about printing machine state for color management in H-UV waterless off-set printing first. These values applied to GRACoL G7 calibration method. This method is one of color standard management method of printing. GRACoL G7 calibration method is possible stable tone reappearance by controlling gray balance by NPDC(Natural Printing Density Curve). Also, this study used values to make device profile as result that is gotten by application of GRACoL G7 calibration method. This profile was applied to CMS(Color Management System) of H-UV waterless off-set printing, and the result was possible by color management that correspond in printing quality standard of ISO 12647-2 and GRACol 2006 specifications.

최신 현미경을 이용한 섬유 및 종이의 성질 분석(제1보)-Confocal Laser Scanning Microscope를 이용한 섬유 밑 종이의 성질 분석- (Use of modern microscopes in Analyzing fiber and Paper Properties( I )-Use of CLSM in Analyzing Fiber and Paper Properties-)

  • 김철환
    • 펄프종이기술
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    • 제30권1호
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    • pp.7-17
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    • 1998
  • With the advent of CLSM in the end of 1980s, it has been applied to the field of pulp and paper science in various ways. This study showed the potentials of CLSM In analyzing a change of pulp fiber and paper properties before and after mechanical treatment. In particular, a quantification of internal fibrillation has been done using cross-sectional images of fibers and image analysis technique, then evaluated the effects of fiber wall delamination on fiber and paper properties. It showed that the delaminated fibers were closely associated to development of the interfiber bonding in a fiber network. The CLSM made it possible to investigate a density profile along the sheet thickness, which was created by some papermaking processes like pressing, drying and calendering. Through the attempt to observe the forming procedure of a fiber network during handsheet making, the CLSM images showed that the pressing stage was considered greatly to contribute to generation of interfiber bonding with removing a free water and partly a bound water between fibers. In addition, the CLSM could be used to illustrate not only a surface profile of paper showing the extent of smoothness or roughness, but also a density profile in a B-direction of the network. Finally it became evident that the CLSM could be used as an excellent tool to predict development in fiber and paper properties before and after mechanical treatment during papermaking processes.

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고지혈증 랫트를 이용한 황금, 황련, 대황의 항고지혈 효과 (Antihyperlipidemic Activity of Scutellaris baicalensis Georg., Coptidis japonica Makino and Rhei koreanum Nakai on Experimental Hyperlipidemia in Rats)

  • 노환성;고우경;김운자;박건구;조영환;박형섭
    • Journal of Pharmaceutical Investigation
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    • 제26권3호
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    • pp.215-219
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    • 1996
  • Active component was sought among three herb medicines, which are used in combination as a traditional medicine prescribed for patients with hyperlipidemia related diseases. Antihyperlipidemic effect of this remedy has previously been shown model by the authors on the animal model. Hyperlipidemia was induced on male Wistar rats by keeping them on high lipid diet for one week, as previously described by the authors. Blood lipid profile was verified on these rats by measuring total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL). Then, the diet was changed to normal. At the same time, methanol extracts of Scutellaris baicalensis Georg.(radix), Coptidis japonica Makino(rhizoma) or Rhei koreanum Nakai(rhizoma) were given on daily basis, and changes in the blood lipid profile were monitored for 4 weeks. Methanol extract of Scutellaris baicalensis Georg. significantly reduced the TC value, implying the in vivo antihyperlipidemic effect.

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WASHINGTON PHOTOMETRY OF THE GLOBULAR CLUSTERS IN THE VIRGO GIANT ELLIPTICAL GALAXY M86

  • Park, Hong-Soo
    • 천문학회지
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    • 제45권3호
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    • pp.71-84
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    • 2012
  • We present a photometric study of the globular clusters (GCs) in the Virgo giant elliptical galaxy M86 based on Washington $CT_1$ images. The colors of the GCs in M86 show a bimodal distribution with a blue peak at ($C-T_1$) = 1.30 and a red peak at ($C-T_1$) = 1.72. The spatial distribution of the red GCs is elongated similar to that of the stellar halo, while that of the blue GCs is roughly circular. The radial number density profile of the blue GCs is more extended than that of the red GCs. The radial number density profile of the red GCs is consistent with the surface brightness profile of the M86 stellar halo. The GC system has a negative radial color gradient, which is mainly due to the number ratio of the blue GCs to the red GCs increasing as galactocentric radius increases. The bright blue GCs in the outer region of M86 show a blue tilt: the brighter they are, the redder their mean colors get. These results are discussed in comparison with other Virgo giant elliptical galaxies.

Photometric properties of the globular cluster system of the massive elliptical galaxy M86

  • 박홍수;이명균
    • 천문학회보
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    • 제38권1호
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    • pp.58.2-58.2
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    • 2013
  • We present a photometric study of the globular clusters (GCs) in the giant elliptical galaxy M86 in the Virgo Cluster, using the Washington $CT_1$ images taken at the KPNO 4 m telescope. The color distribution of the GCs in M86 is bimodal. The radial number density profile of the blue GCs decreases more slowly as the galactocentric distance increases than that of the red GCs. The density profile of the red GCs is similar to the surface brightness profile of M86 stellar halo. The blue GCs have a roughly circular spatial distribution, while the red GCs have a spatial distribution somewhat elongated, which is consistent with the distribution of the galaxy stellar light. M86 GCs have the negative radial color gradient because the number ratio of the blue GCs to the red GCs increases as galactocentric radius increases. The mean color of the red GCs is similar to that of the stellar halo. The bright blue GCs in the outer region of M86 reveal a blue tilt that the mean colors of the blue GCs get redder as they get brighter. We discuss these results in comparison with other giant elliptical galaxies in the Virgo Cluster.

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Effect of Lactobacillus acidophilus based probiotic product supplementation on the blood profile, fecal noxious gas emission, and fecal shedding of lactic acid bacteria and coliform bacteria in healthy adult Beagle dogs

  • Sun, Hao Yang;Kim, In Ho
    • 농업과학연구
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    • 제47권3호
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    • pp.437-443
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    • 2020
  • The aim of this study was to evaluate the effect of Lactobacillus acidophilus probiotic (LAP) product supplementation on the blood profile, fecal noxious gas emission, and fecal shedding of lactic acid bacteria and coliform bacteria in healthy adult Beagle dogs. In total, 14 Beagle dogs with an average initial body weight of 10.19 ± 0.61 kg were randomly assigned into two dietary treatments,with and without LAP supplementation, for a 28-day feeding trial. At the end of the experiment, there was no significant (p > 0.05) difference in the concentration of serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), white blood cell (WBC), red blood cell (RBC), blood lymphocyte percentage, fecal hydrogen sulfide (H2S) and total mercaptans (R.SH) emission, and fecal coliforms counts. However, the serum concentrations of the triglyceride and fecal ammonia (NH3) emission of the LAP treatment were significantly (p < 0.05) decreased in the group compared with the CON dogs. Fecal total lactic acid bacteria counts were significantly (p < 0.05) increased in the LAP treatment. In conclusion, the supplementation of LAP in Beagle dog diets could decrease the blood triglyceride level and enhance the gut Lactobacillus count which may have positive effects on dogs.

A Study on Accuracy Improvement of SBAS Ionospheric Correction Using Electron Density Distribution Model

  • Choi, Bong-Kwan;Han, Deok-Hwa;Kim, Dong-Uk;Kee, Changdon
    • Journal of Positioning, Navigation, and Timing
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    • 제8권2호
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    • pp.59-68
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    • 2019
  • This paper proposed a method to estimate the vertical delay from the slant delay, which can improve accuracy of the ionospheric correction of SBAS. Proposed method used Chapman profile which is a model for the vertical electron density distribution of the ionosphere. In the proposed method, we assumed that parameters of Chapman profile are given and the vertical ionospheric can be modeled with linear function. We also divided ionosphere into multi-layer. For the verification, we converted slant ionospheric delays to vertical ionospheric delays by using the proposed method and generated the ionospheric correction of SBAS with vertical delays. We used International Reference Ionosphere (IRI) model for the simulation to verification. As a result, the accuracy of ionospheric correction from proposed method has been improved for 17.3% in daytime, 10.2% in evening, 2.1% in nighttime, compared with correction from thin shell model. Finally, we verified the method in the SBAS user domain, by comparing slant ionospheric delays of users. Using the proposed method, root mean square value of slant delay error decreased for 23.6% and max error value decreased for 27.2%.

축전 결합형 플라즈마원에 대한 전자기장의 2차원 공간 의존성 계산 (The Calculation of Two Dimensional Spatial Profile of Electromagnetic Field for Capacitively Coupled Plasma Source)

  • 김용일;윤남식
    • 한국진공학회지
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    • 제17권5호
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    • pp.400-407
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    • 2008
  • 본 연구에서는 축전 결합형 플라즈마원에 대한 전자기장의 2차원 공간 의존성을 계산하였다. 1차원 유체 방정식을 기반으로 축전 전기장과 전도 전류 밀도의 axial 방향 공간 의존성을 계산한 후, radial 방향으로는 맥스웰 방정식의 해를 ${\omega}r/c$에 대한 power series로 전개하여 전자기장의 2차원 공간 의존성을 계산하였다.

목이버섯 섭취가 복부비만 여성의 골밀도 및 혈청지질농도에 미치는 영향 (The Effects of Auricularia auricula-judae on Blood Lipids Profile and Bone Density of Middle Aged Abdominal Obese Women)

  • 한정순;김재근;김애정
    • 한국식품영양학회지
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    • 제25권4호
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    • pp.1075-1080
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    • 2012
  • 본 연구는 안전하면서 효율적으로 비만을 개선시키는데 도움이 될 수 있는 식품소재로 목이버섯을 선정하여 복부 비만이 있는 중년 여성의 골밀도 및 혈청지질농도에 미치는 영향에 대하여 알아보고자 하였다. 30~50대의 복부비만 여성 30명에게 4주 동안 대조군은 목이버섯을 섭취시키지 않았고, 실험군은 목이버섯을 식사와 함께 섭취하도록 하였다. 실험 전 후 골밀도(T-score, Z-score), 총 콜레스테롤, HDL-콜레스테롤, LDL-콜레스테롤, 중성지방을 측정하였다. 연구결과, 목이버섯 섭취군과 대조군 간에 T-score와 Z-score는 유의한 차이를 보이지 않았지만, 목이버섯 섭취군의 혈청 총 콜레스테롤, LDL-콜레스테롤 및 중성지방 수준이 대조군에 비해 유의하게 감소되었다.