scholarly journals The Application of COMSOL Multiphysics in Direct Current Method Forward Modeling

2011 ◽  
Vol 3 ◽  
pp. 266-272 ◽  
Author(s):  
Xiaolong Wang ◽  
Hui Yue ◽  
Guangliang Liu ◽  
Zhao Zhao
Author(s):  
Oluseun A. Sanuade ◽  
Joel O. Amosun ◽  
Tokunbo S. Fagbemigun ◽  
Ajibola R. Oyebamiji ◽  
Kehinde D. Oyeyemi

2013 ◽  
Vol 411-414 ◽  
pp. 1619-1624
Author(s):  
Xiang Jun Meng ◽  
Huai Shan Liu ◽  
Xun Hua Zhang

Surveying the damaged site on anticorrosion coating of Underground metal pipeline is currently a realistic problem in pipe network construction projects, They are detected through artificial field source method (DC method), including Person method,potential test method,Close interval pipe-to-soil potential survey and Direct Current Voltage Gradient method, but the principle of detecting about electrical method rare mentioned, the article discusses the forward modeling and inversion method of Surveying the specific damaged site on anticorrosion coating of Underground metal pipeline by DC method in great detail, Through calculation and analysis, The authors believe that the DC method is effective in detecting the damaged site on anticorrosion coating of Underground metal pipeline.


2010 ◽  
Vol 171-172 ◽  
pp. 171-174
Author(s):  
Hong Cheng ◽  
Peng Kun Liu ◽  
Yu Ling Wang ◽  
Chang Xin Nai

The dipole spacing can directly affects the detecting sensitivity and accuracy in the landfill leakage detection by the high voltage direct current method. Based on the high voltage DC detecting model, the impact of dipole spacing on locating leaks is analyzed taking a single leak and multiple leaks as example. The results show that the greater the dipole spacing is, the higher the detecting sensitivity is; the smaller the dipole spacing is, the higher the detecting accuracy is. For multiple leaks, only one leak can be located when the dipole spacing is greater than the distance between the two leaks. In order to detect all leaks correctly, the dipole spacing should be smaller than the distance between the two leaks.


2002 ◽  
Vol 57 (3-4) ◽  
pp. 129-135
Author(s):  
Hsin-Yi Hsu ◽  
Chao-Chen Yang

The conductivities of the binary room-temperature molten salt (RTMS) systems ZnCl2-N-nbutylpyridinium chloride (BPC), ZnCl2 -1-ethyl-3-methylimidazolium chloride (EMIC) and ZnCl2 - benzyltriethylammonium chloride (BTEAC) have been measured at different temperatures and compositions by a d.c. four-probes method. The conductivities of the three RTMS are in the order ZnCl2-EMIC > ZnCl2-BPC > ZnCl2-BTEAC. In ZnCl2-BPC the conductivity at 70 to 150 °C, is maximal for 40 mol% ZnCl2. In ZnCl2 - EMIC, the conductivity below 130 °C is almost constant for 30 to 50 mol% ZnCl2 and has the lowest activation energy 25.21 kJ/mol. For these two systems, the conductivities decrease rapidly beyond 50 mol% ZnCl2 owing to the rapid increase in cross-linking and resultant tightening of the polyelectrolyte structure. As to the ZnCl2-BTEAC system, the conductivities at 110 - 150 °C decrease slowly for 30 - 60 mol% ZnCl2. The conductivities of the ZnCl2-EMICmelt are compared with those of the AlCl3-EMIC melt previously studied. The stability of the ZnCl2-EMIC melt system is explored by the effect of the environment on the conductivity and the Far Transmission Infra Red (FTIR) spectrum. It reveals that the effect is slight, and that the ZnCl2-EMIC melt may be classified as stable.


Author(s):  
Sofiya P. Grakhova ◽  
◽  
Svetlana B. Bortnikova ◽  
Grigoriy L. Panin ◽  
◽  
...  

In the summer, studies were carried out on the Tokarev crater (Karymsky Volcanic Center, Kamchatka). The results of three–dimensional electrotomography are obtained, which describe in sufficient detail the topography and heterogeneities of the bottom. The studies were carried out using the author’s floating installation of multi–electrode sounding by the direct current method based on Iris Syscal Pro equipment. The depth of research did not exceed 80 meters, which was enough to describe the structure of the Maar.


2014 ◽  
Author(s):  
Adrian Nur ◽  
Alifah Rahmawati ◽  
Noor Izzati Ilmi ◽  
Samsudin Affandi ◽  
Arief Widjaja

2019 ◽  
Author(s):  
Ole Seibt ◽  
Dennis Truong ◽  
Niranjan Khadka ◽  
Yu Huang ◽  
Marom Bikson

AbstractTranscranial Direct Current Stimulation (tDCS) dose designs are often based on computational Finite Element Method (FEM) forward modeling studies. These FEM models educate researchers about the resulting current flow (intensity and pattern) and so the resulting neurophysiological and behavioral changes based on tDCS dose (mA), resistivity of head tissues (e.g. skin, skull, CSF, brain), and head anatomy. Moreover, model support optimization of montage to target specific brain regions. Computational models are thus an ancillary tool used to inform the design, set-up and programming of tDCS devices, and investigate the role of parameters such as electrode assembly, current directionality, and polarity of tDCS in optimizing therapeutic interventions. Computational FEM modeling pipeline of tDCS initiates with segmentation of an exemplary magnetic resonance imaging (MRI) scan of a template head into multiple tissue compartments to develop a higher resolution (< 1 mm) MRI derived FEM model using Simpleware ScanIP. Next, electrode assembly (anode and cathode of variant dimension) is positioned over the brain target and meshed at different mesh densities. Finally, a volumetric mesh of the head with electrodes is imported in COMSOL and a quasistatic approximation (stead-state solution method) is implemented with boundary conditions such as inward normal current density (anode), ground (cathode), and electrically insulating remaining boundaries. A successfully solved FEM model is used to visualize the model prediction via different plots (streamlines, volume plot, arrow plot).


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