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Showing 1 to 20 of 34 for “"Diffusion problems"”.
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Energy methods for reaction-diffusion problems
Nonlinear reaction-diffusion equations arise in many areas of applied sciences such as combustion modeling, population dynamics, chemical kinetics, etc. A fundamental problem in the studies of these equations is to understand the long time behavior of solutions of the associated Cauchy problem. …
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Layer-adapted meshes for convection-diffusion problems
… on numerical methods for singular perturbation problems - in particular stationary convection-dominated convection-diffusion problems. More precisely it is devoted to the construction and analysis of layer-adapted meshes underlying these numerical methods. An early important contribution towards …
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Diffusion problems and degradation of bearing overlays
The corrosion and degradation of Pb-Sn bearing overlays Is a bilateral process . During service, the lubricant becomes corrosive due to the breakdown of inhibitors with subsequent oxidation occurring at operating temperatures (120-170[degrees]). ...
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Diffusion problems in lead-tin overlay bearings
… in the automotive bearing industry. The inter-diffusion of tin in the overlay and the copper in the underlying substrate results in the formation of copper-tin intermetallic compounds, consequently depleting tin in the overlay. This renders the bearing subject to corrosion in degraded oil. …
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Adaptive refinement methods for singularly perturbed convection-diffusion problems
Contains fulltext : 145683.pdf (Publisher’s version ) (Open Access)
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The finite element method applied to neutron diffusion problems.
Massachusetts Institute of Technology. Dept. of Nuclear Engineering. Thesis. 1973. Nucl.E.
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On numerical methods for direct and inverse convection-diffusion problems
De thesis bestaat uit 3 delen. In het eerste deel komen oplossingsmethoden van “directe” of “voorwaartse” randwaardeproblemen aan bod. In hoofdstuk 2 wordt een niet-lineair convectie-diffusievraagstuk beschouwd. Dit vraagstuk modeleert de verspreiding van contaminanten in de ondergrond ten gevolge …
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Moving Mesh Finite Element Method for Time Dependent Convection-Diffusion Problems
… true for singularly perturbed convection-diffusion problems. In the presence of vanishing molecular diffusivity, MM- FEM may not suffice. The numerical method may exhibit under-diffusive properties and other methods need to be integrated into the classic Galerkin formulation. We implement …
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Performance Characteristics of Specified Power Reactors in Multidimensional Neutron Diffusion Problems
The multigroup neutron diffusion equations with the constraint of specified power distributions are investigated by the application of the straight-line method which can be considered as the limiting case of zero mesh space in the finite difference method. The standard partial differential form of …
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Diffusion Problems in Wound Healing and a Scattering Approach to Immune System Interactions
… depth and develop a time-independent form of the diffusion equation relevant to the study of the CSD phenomenon. It transpires that the range of CSD sizes for a reasonable estimate of parameter values is 1mm-1cm. More realistic estimates await the appropriate experimental data.</p> <p>The …
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Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices
… performed customarily using two-energy-group diffusion theory (no angular dependence) for a node-homogenized reactor model. The work presented here is concerned with reducing the loss in accuracy entailed when going from Transport to Diffusion. To this end a new method of calculating the …
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Efficient reduced-basis approximation of scalar nonlinear time-dependent convection-diffusion problems, and extension to compressible flow problems
… applied to nonlinear time-dependent convection-diffusion parameterized partial differential equations (PDEs). A proper orthogonal decomposition (POD) procedure is used for the construction of reduced-basis approximation for the field variables. In the presence of highly nonlinear terms, …
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The Partial Current Balance Method: A Local Green's Function Technique for the Numerical Solution of Multidimensional Neutron Diffusion Problems
Made available in DSpace on 2014-12-14T06:25:55Z (GMT). No. of bitstreams: 1 7606706.pdf: 4757919 bytes, checksum: 36a8981516e64055a16e86c426d56c4d (MD5) Previous issue date: 1975
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A Nodal Approach to Arbitrary Geometries, and Adaptive Mesh Refinement for the Nodal Method
… of this modified implementation to convection-diffusion problems proves that the coarse mesh efficiency of the nodal method can be maintained by taking advantage of ""off the shelf"" advanced solver technology."
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Implicit-explicit methods for time-dependent PDE’s
… partial differential equations. For problems with terms of different types, implicit-explicit (IMEX) schemes have been used, especially in conjunction with spectral methods. For convection-diffusion problems, for example, one would use an explicit scheme for the convection term and an …
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Towards next generation ocean models : novel discontinuous Galerkin schemes for 2D unsteady biogeochemical models
… are incubated and evaluated by solving test problems, and important numerical issues related to efficiency are examined. The results of other research groups towards developing the second generation of ocean models are first reviewed. Next, the Discontinuous Galerkin (DG) method for solving …
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Developments in nodal reactor analysis tools for hexagonal geometry
… for the solution of multigroup multidimensional diffusion problems in hexagonal geometry is developed and implemented into the FORTRAN code HEXPEDITE. The algorithm is adapted for modern computer features including vector and concurrent computations and demonstrates high efficiency and accuracy …
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High Resolution Time-Limiter Schemes for Conservation Laws
… may generate strong oscillations in non-smooth problems. The new Limited-DIRK3 scheme (L-DIRK3) is proposed. For convenience of applications to systems of equations, we also propose a new and convenient construction of time-limiter, which allows an arbitrary choice of reference quantity with …
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Parameter estimation and adaptive modeling studies in ocean mixing
… for parameter estimation in straightforward diffusion problems and develop ideas and distributed computational schemes for the automated evaluation of physical and numerical parameters of ocean models. This is one step of "adaptive modeling." Adaptive modeling consists of the automated …
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