• 제목/요약/키워드: shrinking sheet

검색결과 6건 처리시간 0.019초

Numerical Study of Entropy Generation with Nonlinear Thermal Radiation on Magnetohydrodynamics non-Newtonian Nanofluid Through a Porous Shrinking Sheet

  • Bhatti, M.M.;Abbas, T.;Rashidi, M.M.
    • Journal of Magnetics
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    • 제21권3호
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    • pp.468-475
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    • 2016
  • In this article, entropy generation on MHD Williamson nanofluid over a porous shrinking sheet has been analyzed. Nonlinear thermal radiation and chemical reaction effects are also taken into account with the help of energy and concentration equation. The fluid is electrically conducting by an external applied magnetic field while the induced magnetic field is assumed to be negligible due to small magnetic Reynolds number. The governing equations are first converted into the dimensionless expression with the help of similarity transformation variables. The solution of the highly nonlinear coupled ordinary differential equation has been obtained with the combination of Successive linearization method (SLM) and Chebyshev spectral collocation method. Influence of all the emerging parameters on entropy profile, temperature profile and concentration profile are plotted and discussed. Nusselt number and Sherwood number are also computed and analyzed. It is observed that entropy profile increases for all the physical parameters. Moreover, it is found that when the fluid depicts non-Newtonian (Williamson fluid) behavior then it causes reduction in the velocity of fluid, however, non-Newtonian behavior enhances the temperature and nanoparticle concentration profile.

전단 및 교축변형이 조합된 복합스피닝 공정에 관한 연구 (Study on the Spinning Processes Combined with Shear and Shrinking Deformation)

  • 이항수;강정식
    • 소성∙가공
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    • 제8권5호
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    • pp.507-519
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    • 1999
  • An approach using the energy method has veen proposed for the analysis of cone spinning having the complicated deformation modes mixed by shear and normal deformation. In the proposed method, the corresponding solution is found through optimization of the total energy dissipation with respect to the parameters assumed by the velocity field defined as the variation of the length in longitudinal direction. The sheet blank is divided into three layers to consider the bending effect and the energy dissipated by shear deformation is superposed to the energy consumption due to normal deformation related with the shrinking deformation is superposed to the energy consumption due to normal deformation related with the shrinking deformation of axi-symmetric sheet element for the evaluation of total deformation energy. In order to check the validity of the proposed method, the complex spinning for making the conical cup is analyzed and the computed results are compared with the experimental results. In comparison of the computed results with existing experimental results,, the good agreement is obtained for the variation of outer radius and the distribution of thickness, and it has thus been shown that the present approach is applicable to the analysis of complex spinning.

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GMT-Sheet 성형품의 표면요철에 미치는 성형조건의 영향 (Effects of Molding Condition on Surface Unevenness of GMT-Sheet Moldings)

  • 김형석;김진우;김용재;이동기
    • Composites Research
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    • 제23권5호
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    • pp.30-38
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    • 2010
  • 성형조건에 따른 GMT-Sheet를 관찰하여, 성형품 표면의 불량원인을 조사했다. 현미경 관찰 결과, GMT-Sheet 성형품의 표면에서 구정, 섬유돌출, 크랙, 섬유노출, 마이크로 웰드라인, 핀홀, 여파굴곡곡선 등의 결함을 발견했다. 이 결함들은 요철의 발생원인이고, 표면 광택에 영향을 주는 현상이다. 그리고 표면거칠기에 영향을 주는 요철의 가장 주요한 발생원인은 보압 냉각 과정에서 발생하는 모재의 수축이었다. 성형 시의 보압하중이 높을수록 GMT-Sheet 성형품 표면은 좋아졌다. 또한 서냉실험에서는 탈형온도가 낮을수록 성형품의 표면이 좋아졌다.

복합 코발트 실리사이드 공정에 따른 게이트 산화막의 특성변화 (Characteristics of Gate Oxides with Cobalt Silicide Process)

  • 송오성;정성희;이상돈;이기영;류지호
    • 한국재료학회지
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    • 제13권11호
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    • pp.711-716
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    • 2003
  • Gate length, height, and silicide thickness have all been shrinking linearly as device density has progressively increased over the years. We investigated the effect of the cobalt diffusion during the silicide formation process on the 60$\AA$-thick gate oxide lying underneath the Ti/Co and Co/Ti bilayers. We prepared four different cobalt silicides, which have similar sheet resistance, made from the film structure of Co/Ti(interlayer), and Ti(capping layer)/Co, and peformed the current-voltage, time-to-break down, and capacitance-voltage measurements. Our result revealed that the cobalt silicide process without the Ti capping layer allowed cobalt atoms to diffuse into the upper interface of gate oxides. We propose that 100$\AA$-thick titanium interlayer may lessen the diffusion of cobalt to gate oxides in 1500-$\AA$ height polysilicon gates.

How Have Indian Banks Adjusted Their Capital Ratios to Meet the Regulatory Requirements? An Empirical Analysis

  • NAVAS, Jalaludeen;DHANAVANTHAN, Periyasamy;LAZAR, Daniel
    • The Journal of Asian Finance, Economics and Business
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    • 제7권11호
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    • pp.1113-1122
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    • 2020
  • The purpose of this study is to examine how the Indian banks have adjusted their risk-based capital ratios during 2009-2018 to meet the regulatory requirements. Banks can, in principle, increase their risk-based regulatory capital ratio, either by increasing their levels of regulatory capital or by shrinking their risk-weighted assets by adjusting asset growth or risk in the portfolio. We investigate banks' capital behavior by decomposing the change in the capital ratio into the contribution of its components and analyzing their variance across regulatory regimes and banks' ownerships. We further investigate how each component of the capital ratio is adjusted by the banks by breaking down them into balance sheet items. We find that the banks' capital behavior significantly differed between public and private sector banks and between the two regulatory regimes. During Basel II, banks, in general, followed a strategy of aggressive asset growth with increased risk-taking. The decline in the CRAR because of such an expansionary strategy was adjusted by augmenting additional capital. However, during Basel III, due to higher capital requirements, both in terms of quantity and quality, banks followed a strategy of cutting back their asset growth and reducing the risk in their portfolio to maintain their CRAR.