ON GENERATING RANDOM POTENTIALS

2012 ◽  
Vol 11 (04) ◽  
pp. 1250026 ◽  
Author(s):  
M. SUÑÉ SIMON ◽  
J. M. SANCHO ◽  
A. M. LACASTA
Keyword(s):  
Real Space ◽  
Fourier Space ◽  
Random Potentials ◽  
Practical Applications ◽  
Gaussian Potential ◽  
Brownian Particles ◽  
Straightforward Method ◽  
Transport And Diffusion ◽  
Potential Landscape ◽  
And Diffusion

The study of transport and diffusion of Brownian particles in disorder media needs the generation of random potentials with well prescribed statistical properties. Here we present a straightforward method to build a Gaussian potential landscape with an arbitrary spatial correlation with the only requirement of isotropy. The method has the particularity that, although it uses the Fourier space, all its constraints and information are in real space. As practical applications we construct three types of Gaussian disordered correlations: Normal, exponential and power-law. These three cases cover a variety of physical situations.

Transport and diffusion of Brownian particles in a tilted deformable potential

2020 ◽  
Vol 541 ◽  
pp. 123284
Author(s):  
M.F. Kepnang Pebeu ◽  
R.L. Woulaché ◽  
C.B. Tabi ◽  
T.C. Kofane
Keyword(s):  
Brownian Particles ◽  
Transport And Diffusion ◽  
And Diffusion

Shape Potential Effects on Transport and Diffusion Phenomena

2017 ◽  
Vol 16 (02) ◽  
pp. 1750011 ◽  
Author(s):  
A. M. Fopossi Mbemmo ◽  
G. Djuidjé Kenmoé ◽  
T. C. Kofané
Keyword(s):  
Diffusion Coefficient ◽  
Mean Square Displacement ◽  
Critical Force ◽  
Potential Shape ◽  
Brownian Particles ◽  
Normal Diffusion ◽  
Diffusion Phenomena ◽  
Transport And Diffusion ◽  
The Mean ◽  
And Diffusion

We investigate the diffusion of a particle subjected to a non-sinusoidal periodic potential and driven by an external constant force. To study the dynamic of the Brownian particles, we modify the shape of the potential as well as the temperature. This allows us to observe the dependence of the mean square displacement on the shape parameter as well as the diffusion coefficient. For a particular set of the system parameters, the dispersionless transport, normal diffusion and hyperdiffusion are generated in the system. We show that there exists a potential shape where some parameters of the system weakly affect the type of diffusion. The diffusion coefficient reaches its maximum around a critical value of the external field. This pronounced peak of the diffusion coefficient depends on the shape of the potential, so we have evaluated the critical force as a function of the potential features.

scholarly journals Nocturnal Low-Level Jet in a Mountain Basin Complex. Part II: Transport and Diffusion of Tracer under Stable Conditions

2006 ◽  
Vol 45 (5) ◽  
pp. 740-753 ◽  
Author(s):  
Lisa S. Darby ◽  
K. Jerry Allwine ◽  
Robert M. Banta
Keyword(s):  
Surface Pressure ◽  
Salt Lake ◽  
Low Level ◽  
Stable Conditions ◽  
Basin Scale ◽  
Flow Features ◽  
Transport And Diffusion ◽  
Low Level Jet ◽  
The City ◽  
And Diffusion

Abstract Differences in nighttime transport and diffusion of sulfur hexafluoride (SF6) tracer in an urban complex-terrain setting (Salt Lake City, Utah) are investigated using surface and Doppler lidar wind data and large-scale surface pressure differences. Interacting scales of motion, as studied through the URBAN 2000 field program combined with the Vertical Transport and Mixing (VTMX) experiment, explained the differences in the tracer behavior during three separate intensive operating periods. With an emphasis on nighttime stable boundary layer conditions, these field programs were designed to study flow features responsible for the nighttime transport of airborne substances. This transport has implications for air quality, homeland security, and emergency response if the airborne substances are hazardous. The important flow features investigated included thermally forced canyon and slope flows and a low-level jet (LLJ) that dominated the basin-scale winds when the surface pressure gradient was weak. The presence of thermally forced flows contributed to the complexity and hindered the predictability of the tracer motion within and beyond the city. When organized thermally forced flows were present, the tracer tended to stay closer to the city for longer periods of time, even though a strong basin-scale LLJ did develop. When thermally forced flows were short lived or absent, the basin-scale low-level jet dominated the wind field and enhanced the transport of tracer material out of the city.

Pollution plume transport and diffusion studies using fluorescence lidar

1980 ◽  
Vol 19 (15) ◽  
pp. 2524 ◽  
Author(s):  
Burton G. Schuster ◽  
Thomas G. Kyle
Keyword(s):  
Diffusion Studies ◽  
Transport And Diffusion ◽  
Plume Transport ◽  
And Diffusion
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