Numerical study of the scattered Brillouin precursors from an infinite cylinder in lossy dispersive media

2011 ◽  
Author(s):  
Penghui Chen ◽  
Xiaojian Xu
Keyword(s):  
Numerical Study ◽  
Dispersive Media ◽  
Infinite Cylinder

Numerical Study of Crosshole Electromagnetic Tunnel Detection

Geophysics ◽  
2021 ◽  
pp. 1-68
Author(s):  
John W. Neese ◽  
David R. Jackson ◽  
Yingcai Zheng ◽  
Leon A. Thomsen
Keyword(s):  
Fresh Water ◽  
Numerical Study ◽  
Low Frequency ◽  
Open Circuit ◽  
Infinite Cylinder ◽  
Optimum Frequency ◽  
Low Frequencies ◽  
Tunnel Detection ◽  
Lossy Medium ◽  
Water Saturated

Electromagnetic tunnel detection is studied numerically using a 3D analytic infinite lossy homogeneous space solution to magnetic dipole radiation and scattering from an infinite cylinder, in a crosshole context. At low frequencies this serves as a model for a transmit coil radiating a time-varying magnetic field that is then detected from the open-circuit voltage induced on a receive coil. Numerical simulations illustrate how various parameters influence the signal strength and the ability to discern the scattered signal. Tunnel detection is achieved at relatively high frequencies (but below typical GPR frequencies) for fresh water saturated sand and for weathered granite, which are lower loss media; for the coil and tunnel parameters used here, optimum frequencies appear to be between 100 kHz and 1 MHz. Tunnel detection for fresh water saturated clay, a much more lossy medium, can be achieved at a quite low frequency, with an optimum frequency between 1 and 10 kHz. These results suggest that, when a resonant coil system is employed, tunnel detection may be possible in a wider range of earth media than previously reported, when the best-suited choice of frequency is employed.

Numerical study of the low-frequency atomic dynamics in a Lennard-Jones glass

1998 ◽  
Vol 77 (2) ◽  
pp. 473-484 ◽  
Author(s):  
M. Sampoli, P. Benassi, R. Dell'Anna,
Keyword(s):  
Numerical Study ◽  
Low Frequency ◽  
Lennard Jones

Numerical simulation of the tree higro-thermal response in forest fire environment

2020 ◽  
pp. 57-65
Author(s):  
Eusébio Conceiçã ◽  
João Gomes ◽  
Maria Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Xavier Viegas ◽  
...  
Keyword(s):  
Forest Fire ◽  
Numerical Study ◽  
Thermal Response ◽  
View Factor ◽  
Tree Model ◽  
Pine Tree ◽  
Surface Temperatures ◽  
Fire Environment ◽  
Fire Front ◽  
Heat Exchanges

This paper refers to a numerical study of the hypo-thermal behaviour of a pine tree in a forest fire environment. The pine tree thermal response numerical model is based on energy balance integral equations for the tree elements and mass balance integral equation for the water in the tree. The simulation performed considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The virtual three-dimensional tree model has a height of 7.5 m and is constituted by 8863 cylindrical elements representative of its trunks, branches and leaves. The fire front has 10 m long and a 2 m high. The study was conducted taking into account that the pine tree is located 5, 10 or 15 m from the fire front. For these three analyzed distances, the numerical results obtained regarding to the distribution of the view factors, mean radiant temperature and surface temperatures of the pine tree are presented. As main conclusion, it can be stated that the values of the view factor, MRT and surface temperatures of the pine tree decrease with increasing distance from the pine tree in front of fire.

NUMERICAL STUDY FOR THAILAND: MATHEMATICAL MODEL OF PRODUCTION AND LOGISTIC PLANNING FOR SUGARCANES USED IN BIOFUEL PRODUCTION

2013 ◽  
Author(s):  
Pancheewa Benjamasutin ◽  
◽  
Ponthong Rijana ◽  
Phongchayont Srisuwan ◽  
Aussadavut Dumrongsiri
Keyword(s):  
Mathematical Model ◽  
Numerical Study ◽  
Biofuel Production ◽  
Logistic Planning

NUMERICAL STUDY OF PRODUCTION, LOGISTICS AND FACILITY LOCATION PLANNING FOR OIL PALM IN BIO-DIESEL PRODUCTION FOR THAILAND

2013 ◽  
Author(s):  
Artchapong Hassametto ◽  
Preerawadee Chaiboontun ◽  
Chattraporn Prajuabwan ◽  
Laphatrada Khammuang ◽  
Aussadavut Dumrongsiri
Keyword(s):  
Facility Location ◽  
Oil Palm ◽  
Numerical Study ◽  
Location Planning ◽  
Production Logistics ◽  
Diesel Production
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