scholarly journals Radon Transport from Soil to Air and Monte-Carlo Simulation

2021 ◽  
Author(s):  
Ahmad Muhammad ◽  
Fatih Külahcı
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Steady State ◽  
Transport Equation ◽  
Electric Circuit ◽  
Lower Atmosphere ◽  
Global Electric Circuit ◽  
Special Boundary ◽  
Ionization Source ◽  
Radon Space

Abstract The exhalation of geochemical entities from soil to air is significant to understand Lithosphere-Atmospheric relationships. Some of these geochemical entities are capable of modifying the lower atmosphere, and they are employed in various studies. Radon is one of the geochemical gasses widely recognized as a dominant ionization source in near ground regions of the troposphere. The steady state Rn transport equation is considered in many cases for estimating Rn migration from soil to air on the condition that the time evolution is ignored. A method is proposed for estimating radon space-time transport from soil to air. This is achieved by solving the radon transport equation in soil with special boundary conditions. Similar results are obtained with some experimented models, as well as reported radon values in literature for some set of parameter combinations. Strengths and limitations of the method are discussed. The model is useable to study Lithosphere-Atmosphere relationships. It can also be significant in other studies like the Global Electric Circuit or Seismo-Ionospheric studies.

Hydrodynamic and Monte Carlo simulation of steady-state transport and noise in submicrometre silicon structures

1996 ◽  
Vol 11 (6) ◽  
pp. 865-872 ◽  
Author(s):  
E Starikov ◽  
P Shiktorov ◽  
V Gruzinskis ◽  
T González ◽  
M J Martín ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Steady State ◽  
Silicon Structures

Availability Analysis of Single-Component Systems with Various Failure and Repair Distributions

2003 ◽  
Vol 31 (3) ◽  
pp. 258-268 ◽  
Author(s):  
Singiresu S. Rao ◽  
David E. Foster
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Steady State ◽  
Exponential Distribution ◽  
Hazard Function ◽  
Probability Distributions ◽  
Single Component ◽  
Engineering Profession ◽  
Availability Analysis ◽  
Component Systems

Due to the demands on the engineering profession, all products and systems are expected to satisfy certain availability requirements. The availability is a measure of the readiness of a product or system for use at any specified time. In this work, the availability of single-component systems is addressed. Monte Carlo simulation is used to estimate the availability of the system, assuming that the failure and repair times follow exponential, normal (Gaussian), and uniform probability distributions. The results are compared. Although the availability functions look very different, the steady-state availability is the same for all. Also, the availability of a component whose hazard function follows the bathtub curve is estimated, and it is found that the exponential distribution is not a good approximation, especially at the earliest stages of operation.

Stability and Shrinkage by Diffusion in Hollow Nanotubes

2007 ◽  
Vol 266 ◽  
pp. 39-47 ◽  
Author(s):  
Alexander V. Evteev ◽  
Elena V. Levchenko ◽  
Irina V. Belova ◽  
Graeme E. Murch
Keyword(s):  
Monte Carlo Simulation ◽  
Exact Solution ◽  
Monte Carlo ◽  
Steady State ◽  
Kinetic Equation ◽  
Boundary Conditions ◽  
Linear Approximation ◽  
Kinetic Monte Carlo ◽  
Quasi Steady State ◽  
Vacancy Mechanism

The shrinkage via the vacancy mechanism of a mono–atomic nanotube is described. Using Gibbs–Thomson boundary conditions an exact solution is obtained of the kinetic equation in quasi steady–state at the linear approximation. A collapse time as a function of the size of a nanotube is determined. Kinetic Monte Carlo simulation is used to test the analytical analysis.

MONTE CARLO SIMULATION OF STEADY-STATE TRANSPORT IN SUBMICROMETER InP AND GaAsn+–i(n)–n+ DIODE

2010 ◽  
Vol 24 (06) ◽  
pp. 549-560 ◽  
Author(s):  
H. ARABSHAHI ◽  
M. REZAEE ROKN-ABADI ◽  
F. BADIEIAN BAGHSIAHI ◽  
M. R. KHALVATI
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Steady State ◽  
Electron Transport ◽  
Anode Voltage ◽  
Electronic States ◽  
Electron Velocity ◽  
Back Scattering ◽  
Simulation Results ◽  
Average Electron

Monte Carlo simulation of electron transport in an InP diode of n+–i(n)–n+ structure is compared with GaAs diode. The anode voltage ranges from 0.5 to 1.5 V. The distributions of electron energies and electron velocities and the profiles of the electron density, electric field and potential and average electron velocity are computed. Based on these data, the near ballistic nature of the electron transport in the 0.2 μm-long diode and the importance of the back-scattering of electrons from the anode n+-layer are discussed. In addition, the effects of the lattice temperature and doping on the length of the active layer are discussed. Electronic states within the conduction band valleys at the Γ, L, and X are represented by non-parabolic ellipsoidal valleys centered on important symmetry points of the Brillouin zone. Our simulation results have also shown that the electron velocity characteristics in InP diode are more sensitive to temperature than in other III–V semiconductors such as GaAs .

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