Anisotropic light propagation in paper

2012 ◽  
Vol 27 (2) ◽  
pp. 500-506 ◽  
Author(s):  
Tomas Linder ◽  
Torbjörn Löfqvist
Keyword(s):  
Monte Carlo ◽  
Theoretical Model ◽  
Monte Carlo Method ◽  
Light Propagation ◽  
Anisotropic Scattering ◽  
Machine Direction ◽  
Photon Transport ◽  
The Monte Carlo Method ◽  
Wood Fibres ◽  
Good Agreement

Abstract We investigate anisotropic light propagation in paper using both a theoretical model and experiments. The theoretical model utilizes the Monte Carlo method to solve the photon transport equation numerically. It is assumed that wood fibres are represented by infinitely long, homogeneous and straight cylinders. The layer-like microstructure and anisotropic orientation of the fibres is considered in the model. The conical scattering by cylindrical objects, the wood fibres, is argued as the main source of anisotropic scattering. Simulations revealed that laterally resolved transmittance exhibits directional dependence. Experiments on light transmitted through a standard kraft liner product confirmed that light in fact do propagate more in the machine direction than in the cross direction. Reasonably good agreement was obtained between experimentally and numerically obtained iso-intensity patterns.

scholarly journals Alignment of Dust Grains by Magnetic Relaxation: A Comparison Between Results Obtained by Two Different Methods

1973 ◽  
Vol 52 ◽  
pp. 187-189
Author(s):  
P. Cugnon
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Magnetic Relaxation ◽  
Planck Equation ◽  
Dust Grains ◽  
Fokker Planck Equation ◽  
The Monte Carlo Method ◽  
Good Agreement ◽  
Fokker Planck

This paper is devoted to a comparison between results obtained by Purcell and Spitzer (1971) using a Monte-Carlo method and by the author (1971) using a Fokker-Planck equation. It is shown that there is a good agreement between the results within the dispersion expected from the Monte-Carlo method.

scholarly journals Evaluation of Average Directional Effective Emissivities of Isothermal Cylindrical-inner-cone Cavitties Using Monte-Carlo Method

2017 ◽  
Vol 27 (4) ◽  
pp. 357 ◽  
Author(s):  
Minh Nguyen Quang ◽  
Binh Nguyen Van
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Geometrical Parameters ◽  
Time Saving ◽  
Infrared Spectral Range ◽  
Reflection Model ◽  
The Monte Carlo Method ◽  
Infrared Spectral ◽  
Cavity Design ◽  
Good Agreement

We have used the Monte Carlo method based on theory of successive reflections and ray tracing to calculate the average normal directional effective emissivities of isothermal cylindrical-inner-cone cavities for various geometrical parameters. A simplified specular-directional diffuse reflection model was applied in our calculations for cavities working in the infrared spectral range. Our results are in good agreement comparing with what obtained by other authors. The algorithm developed by us has an advantage in simplicity and time saving of calculations. It can be used in blackbody cavity design considerations, especially in the cylindrical-inner-cone cases.

The Solution of Transient Radiative Transfer With Collimated Incident Serial Pulse in a Plane-Parallel Medium by the DRESOR Method

2008 ◽  
Vol 130 (10) ◽  
Author(s):  
Qiang Cheng ◽  
Huai-Chun Zhou ◽  
Zhi-Feng Huang ◽  
Yong-Lin Yu ◽  
De-Xiu Huang
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Radiative Transfer ◽  
Incident Radiation ◽  
Anisotropic Scattering ◽  
Time Dependent ◽  
Temporal Response ◽  
One Dimensional ◽  
Unit Energy ◽  
The Monte Carlo Method

A time-dependent distribution of ratios of energy scattered by the medium or reflected by the boundary surfaces (DRESOR) method was proposed to solve the transient radiative transfer in a one-dimensional slab. This slab is filled with an absorbing, scattering, and nonemitting medium and exposed to a collimated, incident serial pulse with different pulse shapes and pulse widths. The time-dependent DRESOR values, representing the temporal response of an instantaneous, incident pulse with unit energy and the same incident direction as that for the serial pulse, were proposed and calculated by the Monte Carlo method. The temporal radiative intensity inside the medium with high directional resolution can be obtained from the time-dependent DRESOR values. The transient incident radiation results obtained by the DRESOR method were compared to those obtained with the Monte Carlo method, and good agreements were achieved. Influences of the pulse shape and width, reflectivity of the boundary, scattering albedo, optical thickness, and anisotropic scattering on the transient radiative transfer, especially the temporal response along different directions, were investigated.

scholarly journals Neutronic modeling of a subcritical system with corium particles and water (from international benchmark)

2020 ◽  
Vol 6 (3) ◽  
pp. 155-160
Author(s):  
Anton D. Smirnov ◽  
Ekaterina V. Bogdanova ◽  
Pavel A. Pugachev ◽  
Ivan S. Saldikov ◽  
Mikhail Yu. Ternovykh ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Scientific Community ◽  
Structural Elements ◽  
The Monte Carlo Method ◽  
Fukushima Daiichi ◽  
Simulation Results ◽  
Subcritical System ◽  
Good Agreement

After the accident at the Fukushima Daiichi NPP, the attention of the scientific community is riveted on how the consequences are being eliminated. Removing corium – a lava-like resolidified mixture of nuclear fuel with other structural elements of the reactor – remains the most difficult task, the solution of which can take several decades. It is extremely important to exclude the occurrence of any emergency processes during the removal of corium. The purpose of this work was to solve a coordinated hydrodynamic and neutronic problem characterized by a large number of randomly oriented and irregularly located corium particles in water as part of the development of a benchmark for this class of problems. Monte Carlo-based precision codes were used to perform a neutronic analysis. The positions of corium particles were determined from the numerical simulation results. The analysis results obtained using the codes involved showed good agreement for all the states considered. It was shown that the modern neutronic codes based on the Monte Carlo method successfully cope with the geometric formation and solution of the problem with a nontrivial distribution of corium particles in water. The results of the study can be used to justify the safety of corium handling procedures, including its extraction from a damaged power unit.

scholarly journals Klein–Nishina formula and Monte Carlo method for evaluating the gamma attenuation properties of Zn, Ba, Te and Bi elements

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
M.S. Al-Buriahi ◽  
Z.A. Alrowaili ◽  
Safa Ezzine ◽  
I.O. Olarinoye ◽  
Sultan Alomairy ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Energy Transfer ◽  
Monte Carlo Method ◽  
Gamma Rays ◽  
Cross Sections ◽  
Transfer Coefficients ◽  
Entire Energy Range ◽  
The Monte Carlo Method ◽  
New Generation ◽  
Good Agreement

Abstract In this work, the Klein–Nishina (K–N) approach was used to evaluate the electronic, atomic, and energy-transfer cross sections of four elements, namely, zinc (Zn), tellurium (Te), barium (Ba), and bismuth (Bi), for different photon energies (0.662 MeV, 0.835 MeV, 1.170 MeV, 1.330 MeV, and 1.600 MeV). The obtained results were compared with the Monte Carlo method (Geant4 simulation) in terms of mass attenuation and mass energy-transfer coefficients. The results show that the K–N approach and Geant4 simulations are in good agreement for the entire energy range considered. As the photon energy increased from 0.662 MeV to 1.600 MeV, the values of the energy-transfer cross sections decreased from 81.135 cm2 to 69.184 cm2 in the case of Bi, from 50.832 cm2 to 43.344 cm2 for Te, from 54.742 cm2 to 46.678 cm2 for Ba, and from 29.326 cm2 to 25.006 cm2 for Zn. The obtained results and the detailed information of the attenuation properties for the studied elements would be helpful in developing a new generation of shielding materials against gamma rays.

Study on Critical Corrosive Ratio of Reinforced Concrete Based on Monte-Carlo Method

2011 ◽  
Vol 105-107 ◽  
pp. 1060-1064
Author(s):  
Yue Shun Chen ◽  
Li Liu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Probability Distribution ◽  
Model Simulation ◽  
Protective Layer ◽  
Statistical Characteristics ◽  
Constant Current ◽  
Accelerated Corrosion ◽  
The Monte Carlo Method ◽  
Good Agreement

Based on the relationship between the displacement and the corresponding strain in protective layer concrete during their corrosive expanding, the strain in protective layer arrives the critical strain have been think as the cracking condition, then a certainty critical corrosive ratio model has been constructed in this paper. Considering the probability distribution and the statistical characteristics of concrete protective layer thickness c, reinforced bar diameter dst and the effectively volume expansion coefficient neff, the Monte-Carlo method have been used to simulate the critical corrosive ratio ρcr, its probability distribution has been shown in good agreement with Weibull distribution and lognormal distribution in results. Through the constant current polarization accelerated corrosion test, the critical corrosive model has been validated. With comparison of critical corrosive ratio which be obtained with the test and the model simulation results respectively, where a good agreement have been shown.

scholarly journals Light Propagation inside Paper and Color Analysis by the Monte Carlo Method.

1994 ◽  
Vol 48 (9) ◽  
pp. 1177-1185
Author(s):  
Sugita Mitsurou ◽  
Yoshinobu Shiraiwa ◽  
Toshiyuki Mizuno ◽  
Akihiro Usami
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Light Propagation ◽  
Color Analysis ◽  
The Monte Carlo Method
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