• 제목/요약/키워드: NU

검색결과 1,028건 처리시간 0.03초

등온사각빔이 부착된 채널에서의 대류열전달 (Convective Heat Transfer in a Channel with Isothermal Rectangular Beams)

  • 이재신;권순석
    • 설비공학논문집
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    • 제7권1호
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    • pp.63-72
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    • 1995
  • Convective heat transfer in a two-dimensional horizontal and vertical channel with isothermal rectangular beams attached to one adiabatic wall is investigated from the numerical solution of Navier-Stokes and energy equations. The solutions have been obtained for dimensionless beam spacings, S/L=1~4, aspect ratios of beam, H/B=0.25~4, Reynolds numbers, Re=50~1000 and Grashof numbers, $Gr=0{\sim}5{\times}10^4$. The total mean Nusselt number, Nu_T for horizontal and vertical channels shows same value at Gr=0. As Gr increases, Nu_T for horizontal channel increases, but Nu_T for vertical channel shows similar value at S/L=2, H/B=0.25, Re=100. The total mean Nusselt number for horizontal channel is higher than that for vertical channel. As H/B increases, $Nu_T$ for both channel decrease at $Gr=10^4$, Re=100.

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A Method for Measurement of Limiting Intrinsic Non-Uniformity Due to Process in CCD-Multiplexers for Focal Plane Arrays

  • Bhan, R.K.;Saxena, R.S.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제2권1호
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    • pp.87-92
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    • 2002
  • We present a simple experimental method for determination of limiting intrinsic fixed-pattern non-uniformity (NU) due to fabrication process in two-dimensional CCD multiplexers (MUXs) that are used for hybrid focal plane arrays. Here, this is done by determining separately the two NUs viz. that are $V_T$ dependent and $V_T$ independent. From these measurements, process dependent NU can be extracted. It is argued that $V_T$ dependent NU can be eliminated by designing novel input circuits whereas $V_T$ independent NU, primarily, dependent on process control and material variations may be reduced but cannot be eliminated completely and hence limits the FPA performance eventually.

Phenol과 DMA 간의 수소결합 (Intermolecular Hydrogen Bond between Phenol and DMAs)

  • 김복혜;이익춘
    • 대한화학회지
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    • 제10권1호
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    • pp.15-17
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    • 1966
  • Phenol과 각 종 Dimethylaniline(DMA)간의 수소결합을 Infrared Spectrophotometer로 연구하였다. 일반으로 DMA는 n-donor 및 ${\pi}$-donor의 2중 역활을 하나 주로 n-donor로 작용하며 phenol의 O-H stretching frequency의 shift(${\Delta}{\nu}$)는 DMA의 basicity에 비례하였고 (${\Delta}{\nu}$) 와 Hammett의 σcontant사이에는 linearity가 성립함을 알았다.

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Mn-Ce 복합 산화물에 의한 톨루엔 촉매 산화 (Toluene Catalytic Oxidation by Manganese-Cerium Bimetallic Catalysts)

  • 천태진;최성우;이창섭
    • 한국환경과학회지
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    • 제14권4호
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    • pp.427-433
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    • 2005
  • Activity of manganese oxide supported on ${\nu}-Al_2O_3$ was increased when cerium was added. Also, cerium-added manganese oxide on ${\nu}-Al_2O_3$ was more effective in oxidation of toluene than that without cerium. XRD result, it was observed that $MnO_2+CeO_2$ crystalline phases were present in the samples. For the used catalyst, a prominent feature has increased by XPS. TPR/TPO profiles of cerium-added manganese oxide on ${\nu}-Al_2O_3$ changed significantly increased at a lower temperature. The activity of $18.2 wt{\%}\;Mn+ 10.0 wt{\%}\;Ce/{\nu}-Al_2O_3$ increased at a lower temperature. The cerium added on the manganese catalysts has effects on the oxidation of toluene.

Concentration Dependences of the Isotropic Raman Line Widths of Acetonitrile and Acetonitrile-d$_3$ in Carbon Tetrachloride

  • Choe, Joong-Chul;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • 제7권1호
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    • pp.63-66
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    • 1986
  • Concentration dependences of the isotropic Raman line widths for the $ {\nu}_1$ (C-H and C-D) and the ${\nu}_2\;(C{\equiv}N)$ modes for $CH_3CN$ and $CD_3CN\;in\;CCl_4$ solutions have been investigated. For the ${\nu}_1$ modes, the dephasing seems to be a good description for the isotropic line broadening in $CCl_4$ solution even though the concentration fluctuation can reproduce the experimental results also. For the ${\nu}_2$ modes, the concentration fluctuation was the dominant mechanism for the concentration-dependent line broadening.

A bimodal Weibull distribution - capacity factor for different heights at sulur

  • Seshaiah, C.V.;Indhumathy, D.
    • Wind and Structures
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    • 제28권1호
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    • pp.63-70
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    • 2019
  • Due to developing environmental concern use of renewable energy source is very essential. The great demand for the energy supply coupled with inadequate energy sources creates an emergency to find a new solution for the energy shortage. The appropriate wind energy distribution is the fundamental requirement for the assessment of wind energy potential available at the particular site essential for the design of wind farms. Hence the proper specification of the wind speed distribution plays a vital role. In this paper the Bimodal Weibull distribution is used to estimate the Capacity factor at the proposed site. The shape and scale parameters estimated using Maximum likelihood method is used as the initial value for extrapolation. Application of this model will give an accurate result overwhelming the concept of overestimation or underestimation of Capacity factor.

Human Embryonic Stem Cells - a Potential Vaccine for Ovarian Cancer

  • Zhang, Zu-Juan;Chen, Xin-Hua;Chang, Xiao-Hong;Ye, Xue;Li, Yi;Cui, Heng
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권9호
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    • pp.4295-4300
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    • 2012
  • Objective: To investigate the therapeutic potential of human embryonic stem cells (hESCs) as a vaccine to induce an immune response and provide antitumor protection in a rat model. Methods: Cross-reactivity of antigens between hESCs and tumour cells was screened by immunohistochemistry. Fischer 344 rats were divided into 7 groups, with 6 rats in each, immunized with: Group 1, hESC; Group 2, pre-inactivated mitotic NuTu-19; Group 3 PBS; Group 4, hESC; Group 5, pre-inactivated mitotic NuTu-19; Group 6, PBS; Group 7, hESC only. At 1 (Groups 1-3) or 4 weeks (Groups 4-6) after the last vaccination, each rat was challenged intraperitoneally with NuTu-19. Tumor growth and animal survival were closely monitored. Rats immunized with H9 and NuTu-19 were tested by Western blot analysis of rat orbital venous blood for cytokines produced by Th1 and Th2 cells. Results: hESCs presented tumour antigens, markers, and genes related to tumour growth, metastasis, and signal pathway interactions. The vaccine administered to rats in Group 1 led to significant antitumor responses and enhanced tumor rejection in rats with intraperitoneal inoculation of NuTu-19 cells compared to control groups. In contrast, rats in Group 4 did not display any elevation of antitumour responses. Western blot analysis found cross-reactivity among antibodies generated between H9 and NuTu-19. However, the cytokines did not show significant differences, and no side effects were detected. Conclusion: hESC-based vaccination is a promising modality for immunotherapy of ovarian cancer.

선형 Roll-CMP에서 공정변수에 관한 통계적 분석 (Statistical Analysis on Process Variables in Linear Roll-CMP)

  • 왕함;이현섭;정해도
    • Tribology and Lubricants
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    • 제30권3호
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    • pp.139-145
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    • 2014
  • Nowadays, most micro-patterns are manufactured during flow line production. However, a conventional rotary chemical mechanical polishing (CMP) system has a limited throughput for the fabrication of large and flexible electronics. To overcome this problem, we propose a novel linear roll-CMP system for the planarization of large-area electronics. In this paper, we present a statistical analysis on the linear roll-CMP process of copper-clad laminate (CCL) to determine the impacts of process parameters on the material removal rate (MRR) and its non-uniformity (NU). In the linear roll-CMP process, process parameters such as the slurry flow rate, roll speed, table feed rate, and down force affect the MRR and NU. To determine the polishing characteristics of roll-CMP, we use Taguchi's orthogonal array L16 (44) for the experimental design and F-values obtained by the analysis of variance (ANOVA). We investigate the signal-to-noise (S/N) ratio to identify the prominent control parameters. The "higher is better" for the MRR and "lower is better" for the NU were selected for obtaining optimum CMP performance characteristics. The experimental and statistical results indicate that the down force and roll speed mainly affect the MRR and the down force and table feed rate determine the NU in the linear roll-CMP process. However, over 186.3 N of down force deteriorates the NU because of the bending of substrate. Roll speed has little relationship to the NU and the table feed rate does not impact on the MRR. This study provides information on the design parameter of roll-CMP machine and process optimization.