The potential of fracture imaging using high‐frequency, single‐hole electromagnetic data

Geophysics ◽  
2002 ◽  
Vol 67 (4) ◽  
pp. 1087-1094 ◽  
Author(s):  
Soon Jee Seol ◽  
Jung Hee Suh ◽  
Yoonho Song ◽  
Hee Joon Kim ◽  
Ki Ha Lee
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
High Frequency ◽  
Least Squares Method ◽  
Thin Sheet ◽  
Integral Equation Method ◽  
Displacement Current ◽  
High Electrical Conductivity ◽  
Single Hole ◽  
Electrical Permittivity

This paper presents an inversion scheme for high‐frequency electromagnetic (EM) data from a single borehole for detection and characterization of fluid‐filled fractures. Water in the fracture zone may be characterized by its high electrical permittivity and, if saline, by high electrical conductivity. High electrical conductivity results in increased attenuation of EM fields, whereas high electrical permittivity reduces the phase velocity of propagating EM fields. Taking advantage of these effects, we use high‐frequency EM fields to detect and characterize fluid‐filled fractures. To demonstrate the feasibility of single‐hole EM imaging, we develop a three‐step inversion scheme to map a fluid‐filled fracture near the borehole and to evaluate its electrical conductivity and permittivity. We assume that a fluid‐filled fracture can be simulated by a conductive thin sheet. To test our inversion scheme, we generated synthetic data using the thin‐sheet integral equation method. A vertical magnetic dipole was used as a source, and the resultant magnetic fields were inverted using a nonlinear least‐squares method. First, the background conductivity and permittivity were obtained using vertical magnetic field data from below and above the transition frequency, at which conduction and displacement current magnitudes are equal. Next, using the phase difference between EM fields at two neighboring frequencies in the wave propagation realm, both the vertical and dipping sheets were successfully mapped using NMO and migration techniques. Electrical properties of the sheet were well resolved by subsequent inversion after having fixed the location of the sheet and host electrical properties. This study shows the potential of imaging the fracture using high‐frequency EM data obtained from single‐hole surveys.

Nanoelectromagnetic of the N-doped single wall carbon nanotube in the extremely high frequency band

Nanoscale ◽  
2017 ◽  
Vol 9 (37) ◽  
pp. 14192-14200 ◽  
Author(s):  
B. Aïssa ◽  
M. Nedil ◽  
J. Kroeger ◽  
M. I. Hossain ◽  
K. Mahmoud ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Frequency Band ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
High Electrical Conductivity ◽  
High Frequency Band ◽  
High Demand ◽  
Extremely High Frequency ◽  
Minimal Thickness

Materials offering excellent mechanical flexibility, high electrical conductivity and electromagnetic interference (EMI) attenuation with minimal thickness are in high demand, particularly if they can be easily processed into films.

STUDYING MULTILAYERED GRAPHENES BY ELECTROPHYSICAL METHODS

2021 ◽  
pp. 100-107
Author(s):  
K. L. Levine ◽  
D. V. Ryabokon ◽  
S. D. Khanin ◽  
R. V. Gelamo ◽  
N. A. Nikonorova
Keyword(s):  
Electrical Conductivity ◽  
Chemical Composition ◽  
Electrical Properties ◽  
Work Function ◽  
Electron Work Function ◽  
Charge Storage ◽  
High Electrical Conductivity ◽  
Free Standing ◽  
Storage Devices

The paper studies multilayer graphenes in the form of free-standing films. The authors provide data about the morphology and electrical properties of films treated with plasma of various chemical composition. It is shown that it is possible to control the electrical properties of the surface and electron work function without significantly affecting its morphology. The obtained samples, combining mechanical flexibility with unreactiveness and high electrical conductivity, are promising for application in flexible charge storage devices.

scholarly journals Control of Electrical and Optical Parameters of Humidity Sensors Active Elements Based on Tin Oxides Films with Variable Composition

2019 ◽  
Vol 10 (2) ◽  
pp. 138-150 ◽  
Author(s):  
D. V. Adamchuck ◽  
V. K. Ksenevich
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Gas Sensors ◽  
Annealing Temperature ◽  
Argon Plasma ◽  
Electromagnetic Spectrum ◽  
Optical And Electrical Properties ◽  
High Electrical Conductivity ◽  
Synthesis Parameters ◽  
Tin Oxides

The aim of this work is development of technique for synthesis of tin oxides films with various stoichiometric composition, characterized by high electrical conductivity and light transmittance in the UV and visible range of the electromagnetic spectrum, for their further application as humidity and gas sensors, as well as electrodes for electro-and photocatalytic converters.Nonstoichiometric SnO/SnO2 /SnO2−δ films were synthesized by reactive magnetron sputtering of tin onto glass substrates in argon plasma with oxygen addition and with subsequent thermal oxidation of the formed layers in air. To change the structural, optical, and electrical properties of the films and to find out the optimal synthesis parameters, the oxygen content during the deposition process and the annealing temperature in air were varied in the range of 0–2 vol. % and of 200–450 °C, respectively. The characterization of the films was carried out using a 4-probe method for measuring the electrical resistance, X-ray diffraction, and optical spectroscopy of light transmission.As a result of a comprehensive analysis of the structural, optical and electrical properties of the films, it was found that the optimal synthesis parameters to obtain the most transparent and conductive coatings promising for use as humidity, gas sensors and in photovoltaic devices are the following: oxygen content in argon plasma during sputtering process is ≈ 0,8–1,2 vol. %, the annealing temperature in air is ≈ 350–375 °C. In this case a polycrystalline film with high electrical conductivity and high transmittance in the visible and UV regions of the electromagnetic spectrum with prevailing of tin dioxide phase with structural defects (oxygen vacancies) is formed.

Inclusion Compounds of Tetracyano Complexes and Their Electrical Properties

1994 ◽  
Vol 59 (11) ◽  
pp. 2436-2446 ◽  
Author(s):  
Mária Reháková ◽  
Anna Sopková ◽  
Vladimír Šály
Keyword(s):  
Electrical Conductivity ◽  
Chemical Composition ◽  
Electrical Properties ◽  
General Formula ◽  
Inclusion Compounds ◽  
High Frequency ◽  
Iodide Ions ◽  
Structure And Morphology ◽  
Composition Structure ◽  
Tetracyano Complexes

The presence of iodine and iodide ions in tetracyanonickelates inclusion compounds with the general formula Ni(B)mNi(CN)4 . n H2O (B = NH3 or ethylenediamine) changes the properties of these compounds. High frequency conductance measurements in the range of 10 - 105 Hz show that the products with ethylenediamine ligands have a higher electrical conductivity than those with NH3 ligands. The differences in the electrical properties between the compounds studied are mainly caused by chemical composition, structure and morphology.

scholarly journals Decomposition of High-Frequency Electrical Conductivity into Extracellular and Intracellular Compartments based on Two-Compartment Model using Low-to-High Multi-b Diffusion MRI

2020 ◽  
Author(s):  
Mun Bae Lee ◽  
Hyung Joong Kim ◽  
Oh-In Kwon
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
High Frequency ◽  
Compartment Model ◽  
Biological Tissues ◽  
Extracellular Medium ◽  
Two Compartment Model ◽  
Random Decision Forests ◽  
Human Experiments ◽  
Micro Structures

Abstract Background: As an object's electrical passive property, the electrical conductivity is proportional to the mobility and concentration of charged carriers that reflect the brain micro-structures. The measured Mb-DWI data by controlling the degree of applied diffusion weights can quantify the apparent mobility of water molecules within biological tissues. Without any external electrical stimulation, magnetic resonance electrical properties tomography (MREPT) techniques have successfully recovered the conductivity distribution at a Larmor-frequency. Methods: This work provides a non-invasive method to decompose the high-frequency conductivity into the extracellular medium conductivity based on a two-compartment model using multi-b diffusion-weighted imaging (Mb-DWI). To separate the intra- and extracellular micro-structures from the recovered high-frequency conductivity, we include higher b-values DWI and apply the random decision forests to stably determine the micro-structural diffusion parameters. Results: To demonstrate the proposed method, we conducted human experiments by comparing the results of reconstructed conductivity of extracellular medium and the conductivity in the intra-neurite and intra-cell body. Human experiments verify that the proposed method can recover the extracellular electrical properties from the high-frequency conductivity using a routine protocol sequence of MRI scan. Conclusion: We have proposed a method to decompose the electrical properties in the extracellular, intra-neurite, and soma compartments from the high-frequency conductivity map, reconstructed by solving the electro-magnetic equation with measured B1 phase signals.

Thermal Management Study of LTCC PIN Photodiode Module

2018 ◽  
Vol 934 ◽  
pp. 13-17
Author(s):  
N.A. Ngah ◽  
Amiza Rasmi ◽  
Azmi Ibrahim ◽  
Zulkifli Ambak ◽  
Mohd Zulfadli Mohamed Yusoff ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Low Temperature ◽  
Thermal Management ◽  
High Frequency ◽  
Thermal Dissipation ◽  
Packaging Materials ◽  
High Electrical Conductivity ◽  
Low Loss ◽  
Pin Photodiode ◽  
High Frequency Application

Multilayer low temperature co-fired ceramic (LTCC) is well known in usage as interconnect substrate, especially in high frequency application due to high electrical conductivity of the conductors and low loss of the LTCC dielectric. As substrate and packaging materials, there are many chips or devices placed on the multilayer LTCC board. In this paper, multilayer LTCC is implemented as the packaging at PIN photodiode (PD) module of the Radio over Fiber (RoF) system with the reason to increase thermal dissipation capacity of the PD module.

scholarly journals Decomposition of high-frequency electrical conductivity into extracellular and intracellular compartments based on two-compartment model using low-to-high multi-b diffusion MRI

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Mun Bae Lee ◽  
Hyung Joong Kim ◽  
Oh In Kwon
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
High Frequency ◽  
Compartment Model ◽  
Biological Tissues ◽  
Extracellular Medium ◽  
Two Compartment Model ◽  
Random Decision Forests ◽  
Human Experiments ◽  
Micro Structures

Abstract Background As an object’s electrical passive property, the electrical conductivity is proportional to the mobility and concentration of charged carriers that reflect the brain micro-structures. The measured multi-b diffusion-weighted imaging (Mb-DWI) data by controlling the degree of applied diffusion weights can quantify the apparent mobility of water molecules within biological tissues. Without any external electrical stimulation, magnetic resonance electrical properties tomography (MREPT) techniques have successfully recovered the conductivity distribution at a Larmor-frequency. Methods This work provides a non-invasive method to decompose the high-frequency conductivity into the extracellular medium conductivity based on a two-compartment model using Mb-DWI. To separate the intra- and extracellular micro-structures from the recovered high-frequency conductivity, we include higher b-values DWI and apply the random decision forests to stably determine the micro-structural diffusion parameters. Results To demonstrate the proposed method, we conducted phantom and human experiments by comparing the results of reconstructed conductivity of extracellular medium and the conductivity in the intra-neurite and intra-cell body. The phantom and human experiments verify that the proposed method can recover the extracellular electrical properties from the high-frequency conductivity using a routine protocol sequence of MRI scan. Conclusion We have proposed a method to decompose the electrical properties in the extracellular, intra-neurite, and soma compartments from the high-frequency conductivity map, reconstructed by solving the electro-magnetic equation with measured B1 phase signals.

scholarly journals High AC and DC Electroconductivity of Scalable and Economic Graphite–Diamond Polylactide Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2835
Author(s):  
Jacek Fal ◽  
Katarzyna Bulanda ◽  
Mariusz Oleksy ◽  
Jolanta Sobczak ◽  
Jinwen Shi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Dielectric Spectroscopy ◽  
Mass Fraction ◽  
Ash Content ◽  
Melt Blending ◽  
Broadband Dielectric Spectroscopy ◽  
Electrical Permittivity ◽  
Magnitude Improvement

Two types of graphite/diamond (GD) particles with different ash content was applied to prepare new electroconductive polylactide (PLA)-based nanocomposites. Four samples of nanocomposites for each type of GD particles with mass fraction 0.01, 0.05, 0.10, and 0.15 were prepared via an easily scalable method—melt blending. The samples were subjected to the studies of electrical properties via broadband dielectric spectroscopy. The results indicated up to eight orders of magnitude improvement in the electrical conductivity and electrical permittivity of the most loaded nanocomposites, in reference to the neat PLA. Additionally, the influence of ash content on the electrical conductivity of the nanocomposites revealed that technologically less-demanding fillers, i.e., of higher ash content, were the most beneficial in the light of nanofiller dispersibility and the final properties.

High Electrical Conductivity in Organic Single-Component Systems Based on 2,5-Dimethylthio-TCNQ

1993 ◽  
Vol 328 ◽  
Author(s):  
J. S. Zambounis ◽  
J. Mizuguchi ◽  
H. Hediger ◽  
J. Pfeiffer ◽  
B. Schmidhalter ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Room Temperature ◽  
Single Component ◽  
Charge Carriers ◽  
Optical And Electrical Properties ◽  
High Electrical Conductivity ◽  
Component System ◽  
Component Systems ◽  
Neighboring Molecule

ABSTRACT2,5-dimethylthio-TCNQ has been newly synthesized, and its optical and electrical properties have been investigated in evaporated films. A high electrical conductivity of σ=2× 10−5 Scm−l has been measured at room temperature. The present single-component system is found to contain 2×1017 spins/cm3. The charge carriers are presumably due to incorporated impurities which give the ESR signals. Carrier hopping is considerably facilitated by close intermolecular S-N contacts between the S atom of the -SCH3 group of one molecule and the N atom of -C≡N group of the neighboring Molecule.

scholarly journals Simultaneously improved electrical properties of crystalline YbAl3 thin films prepared by co-sputtering technique

RSC Advances ◽  
2017 ◽  
Vol 7 (28) ◽  
pp. 17271-17278
Author(s):  
Ran-Ran Li ◽  
Dan-Qi He ◽  
Xin Mu ◽  
Hong-Yu Zhou ◽  
Ping Wei ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
High Power ◽  
Annealing Treatment ◽  
Subsequent Annealing ◽  
High Electrical Conductivity

Crystalline and stoichiometric YbAl3 thin films with high electrical conductivity and high power factors were prepared by a co-sputtering technique and subsequent annealing treatment.

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