Pulsed Ferrite Magnetic Field Generator for Through-the-earth Communication Systems for Disaster Situation in Mines

Bae, Seok; Hong, Yang‐Ki; Lee, Jaejin; Park, Jihoon; Jalli, Jeevan; Abo, Gavin S.; Kwon, Hyuck M.; Jayasooriya, Chandana K. K.

doi:10.4283/jmag.2013.18.1.043

Cited by 8 publications

(2 citation statements)

References 17 publications

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“…Through-the-earth (TTE) communications (sometimes also called sub-surface communications [1]) use extremely low frequency (ELF) or low-frequency (LF) waves to communicate directly through the earth overburden which is generally opaque to higher-frequency conventional radio signals [2][3][4][5][6]. TTE communication systems require less infrastructure that can be exposed to damage in the case of fire, explosion or large ground-fall.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic Environments and Wireless Channels for Through-the-Earth (Tte) Communications in an Underground Coal Mine: Modeling and Measurements

Zhou¹,

Damiano²

2021

PIER M

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Through-the-earth (TTE) communication systems are useful for post-disaster emergency communications due to their likelihood of surviving a mine disaster. The wireless channel and electromagnetic environment (EME) are two primary factors that affect the performance of a TTE system and have not been well understood in a mining environment. This paper reports our recent measurements conducted in an active coal mine to characterize the wireless channel and EME of a TTE system. TTE transmissions were successfully demonstrated in a mine location with a depth of 567 m (1,860 ft) by using ground rods installed on the surface and existing roof bolts in the underground. The results show that the EME in the mine is dominated by the 60-Hz signal and its harmonics for both surface and underground environments. The signal attenuation caused by the channel increases for frequencies greater than 90 Hz, which appears to be an optimum frequency point showing the smallest attenuation. An analytical path loss model for TTE channels is developed and validated using measurement results. This paper provides a measured data set as well as a model that an electricfield TTE system operator or system designer can reference when implementing TTE technologies in a mining environment.

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Section: Introductionmentioning

confidence: 99%

Electromagnetic Environments and Wireless Channels for Through-the-Earth (Tte) Communications in an Underground Coal Mine: Modeling and Measurements

Zhou¹,

Damiano²

2021

PIER M

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“…Single-Wire Earth Return systems have exploited this fact for many decades in rural areas where the cost to install two-terminal (forward and return) wiring is not economical [12]. Other examples that use the earth as an electrical conduit include EM geophysics for underground mapping [13,14] and surface to mine communications [15,16]. Older literature from the pre-World War I era can be found describing similar techniques [17][18][19][20]; the most notable of this literature being the works of Nikola Tesla [19,20].…”

Section: Introductionmentioning

confidence: 99%

Electrical excitation of the local earth for resonant, wireless energy transfer

et al. 2016

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Here we demonstrate wireless energy transfer that exploits the conductivity and permittivity of soil to create a potential gradient on the surface around an earthed electrode, distributing electrical energy over the area. This generated surface potential can be amplified using a special standing-wave receiver for harnessing the distributed energy. We have experimentally mapped the surface potential around the electrode and plotted the received energy covering an area of 1200 m 2 . Key operating parameters are determined with a discussion on optimizing the system efficiency. This technique could address the challenge of distributing electrical energy to many low power devices over large outdoor areas without the use of wires.

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Local Structure and Magnetic Properties of Fe-Mn Nanocrystalline Alloys Fabricated by Mechanical Alloying Technique as a Function of Milling Time

Tarigan¹,

Yang²,

Yu³

2013

Journal of Magnetics

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Structural and magnetic properties of Fe 50 Mn 50 nanocrystalline alloys prepared by the mechanical alloying technique (using commercial Fe and Mn powders as the precursors) are studied as a function of milling time, 1 hr to 48 hrs. The nano-crystallite size and shape are examined by using scanning electron microscopy (SEM). The effect of milling time on structural characterization was investigated using X-ray diffractometer (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS). Both XRD and EXAFS studies showed that the alloying process should be completed after 36 hrs milling. Concerning the magnetic behavior, the data obtained from superconducting quantum interference devices (SQUID) exhibited both magnetic saturation (M s ) and coercivity (H c ) depend strongly on the milling time, which are related to the changes in the crystallite size and magnetic dilution.

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Pulsed Ferrite Magnetic Field Generator for Through-the-earth Communication Systems for Disaster Situation in Mines

Cited by 8 publications

References 17 publications

Electromagnetic Environments and Wireless Channels for Through-the-Earth (Tte) Communications in an Underground Coal Mine: Modeling and Measurements

Electromagnetic Environments and Wireless Channels for Through-the-Earth (Tte) Communications in an Underground Coal Mine: Modeling and Measurements

Electrical excitation of the local earth for resonant, wireless energy transfer

Local Structure and Magnetic Properties of Fe-Mn Nanocrystalline Alloys Fabricated by Mechanical Alloying Technique as a Function of Milling Time

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