Identification of diffusion coefficients in heat equation on the base of non-adiabatic measurements of ferrofluids

2016 ◽  
Author(s):  
Arkadiusz Miaskowski ◽  
Bartosz Sawicki ◽  
Mahendran Subramanian
Keyword(s):  
Heat Equation ◽  
Diffusion Coefficients

scholarly journals Heat diffusion in a channel under white noise modeling of turbulence

2021 ◽  
Vol 4 (4) ◽  
pp. 1-21
Author(s):  
Franco Flandoli ◽  
◽  
Eliseo Luongo
Keyword(s):  
Velocity Field ◽  
Heat Source ◽  
Heat Equation ◽  
White Noise ◽  
Diffusion Coefficients ◽  
Weak Sense ◽  
Passive Scalar ◽  
Heat Diffusion ◽  
Turbulent Fluid ◽  
Deterministic Solution

<abstract><p>A passive scalar equation for the heat diffusion and transport in an infinite channel is studied. The velocity field is white noise in time, modelling phenomenologically a turbulent fluid. Under the driving effect of a heat source, the phenomenon of eddy dissipation is investigated: the solution is close, in a weak sense, to the stationary deterministic solution of the heat equation with augmented diffusion coefficients.</p></abstract>

Interlayer mixing in GaAs/AlxGa1-xAs heterostructures as a result of Se+ ion implantation

1988 ◽  
Vol 46 ◽  
pp. 908-909
Author(s):  
E.G. Bithell ◽  
W.M. Stobbs
Keyword(s):  
Ion Implantation ◽  
Diffusion Coefficients ◽  
Dark Field ◽  
Atomic Mass ◽  
Composition Profile ◽  
Semiconductor Heterostructures ◽  
Transmission Electron ◽  
Microscope Images ◽  
Damage Process ◽  
Electron Energy Loss

It is well known that the microstructural consequences of the ion implantation of semiconductor heterostructures can be severe: amorphisation of the damaged region is possible, and layer intermixing can result both from the original damage process and from the enhancement of the diffusion coefficients for the constituents of the original composition profile. A very large number of variables are involved (the atomic mass of the target, the mass and energy of the implant species, the flux and the total dose, the substrate temperature etc.) so that experimental data are needed despite the existence of relatively well developed models for the implantation process. A major difficulty is that conventional techniques (e.g. electron energy loss spectroscopy) have inadequate resolution for the quantification of any changes in the composition profile of fine scale multilayers. However we have demonstrated that the measurement of 002 dark field intensities in transmission electron microscope images of GaAs / AlxGa1_xAs heterostructures can allow the measurement of the local Al / Ga ratio.

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