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Conduction Process (conduction + process)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

A review of reliable numerical models for three-dimensional linear parabolic problems

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 1 2007
I. Faragó
Abstract The preservation of characteristic qualitative properties of different phenomena is a more and more important requirement in the construction of reliable numerical models. For phenomena that can be mathematically described by linear partial differential equations of parabolic type (such as the heat conduction, the diffusion, the pricing of options, etc.), the most important qualitative properties are: the maximum,minimum principle, the non-negativity preservation and the maximum norm contractivity. In this paper, we analyse the discrete analogues of the above properties for finite difference and finite element models, and we give a systematic overview of conditions that guarantee the required properties a priori. We have chosen the heat conduction process to illustrate the main concepts, but engineers and scientists involved in scientific computing can easily reformulate the results for other problems too. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Current-transport studies and trap extraction of hydrothermally grown ZnO nanotubes using gold Schottky diode

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2010
G. Amin
Abstract High-quality zinc oxide (ZnO) nanotubes (NTs) were grown by the hydrothermal technique on n-Si substrate. The room temperature (RT) current-transport mechanisms of Au Schottky diodes fabricated from ZnO NTs and nanorods (NRs) reference samples have been studied and compared. The tunneling mechanisms via deep-level states was found to be the main conduction process at low applied voltage but at the trap-filled limit voltage (VTFL) all traps were filled and the space-charge-limited current conduction was the dominating current-transport mechanism. The deep-level trap energy and the trap concentration for the NTs were obtained as ,0.27,eV and 2.1,×,1016,cm,3, respectively. The same parameters were also extracted for the ZnO NRs. The deep-level states observed crossponds to zinc interstitials (Zni), which are responsible for the violet emission. [source]

Percolation phenomena in carbon black,filled polymeric concrete

POLYMER ENGINEERING & SCIENCE, Issue 9 2000
L. Rejón
Percolation in carbon black-filled polymeric concrete, is discussed based on the measured changes in electrical conductivity and morphology of the composite at different concentrations of carbon black. The percolation threshold ranged between 6 and 7 wt% (based on resin weight) of carbon black. Above this concentration, the filler particles formed agglomerates in contact with each other, suggesting that the conduction process is nearly ohmic in nature. A power law predicted by percolation theory described the behavior of the conductivity as a function of carbon black content. Microscopic analysis showed the presence of a continuous structure formed by the polyester resin and carbon black, in which silica particles were embedded. [source]

DQ-based simulation of weakly nonlinear heat conduction processes

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 11 2008
S. Tomasiello
Abstract In this paper, an explicit form for the numerical solution of problems in the space,time domain by using quadrature rules is proposed. The compact form of the shape functions recently proposed by the author is useful to the scope. Numerical solutions for the time-dependent one-dimensional nonlinear heat conduction problem are calculated by means of the iterative differential quadrature method, a method proposed by the author and based on quadrature rules. The accuracy of the solution and stability analysis show good performance of the approach. Copyright © 2007 John Wiley & Sons, Ltd. [source]