Last data update: Jun 17, 2024. (Total: 47034 publications since 2009)
Records 1-12 (of 12 Records) |
Query Trace: Damiano N [original query] |
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Electromagnetic environments and wireless channels for through-the-earth (TTE) communications in an underground coal mine: Modeling and measurements
Zhou C , Damiano N . Prog Electromagn Res M Pier M 2021 103 91-101 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 electric-field TTE system operator or system designer can reference when implementing TTE technologies in a mining environment. © 2021, Electromagnetics Academy. All rights reserved. |
Cryogenic air supply for cooling built-in-place refuge alternatives in hot mine
Yan L , Yantek D , Reyes M , Whisner B , Bickson J , Srednicki J , Damiano N , Bauer E . Min Metall Explor 2020 37 (3) 861-871 Built-in-place (BIP) refuge alternatives (RAs) are designed to provide a secure space for miners who cannot escape during a mine emergency. Heat and humidity buildup within RAs may expose miners to physiological hazards such as heat stress. To minimize the risk of heat stress, Title 30 Code of Federal Regulations (CFR), or 30 CFR, mandates a maximum allowable apparent temperature (AT) for an occupied RA of 35 °C (95 °F) (MSHA 2008 [1]). The National Institute for Occupational Safety and Health (NIOSH) has conducted extensive research on the thermal environment of occupied RAs intended for use in underground coal mines. NIOSH research has demonstrated that a fully occupied BIP RA can exceed the AT limit by > 5.6 °C (10 °F) in mines with elevated mine strata and air temperatures (Bissert et al. 2017 [2]). In this circumstance, an RA cooling system could provide a solution. This paper provides an overview of test methodology and findings as well as guidance on improving the performance of a cryogenic air system prototype by optimizing the flow rate, increasing the tank storage capacity, and improving the efficiency of the heat exchanger of the cryogenic system. This may enable BIP RAs to meet the 35 °C (95 °F) AT limit in mines with elevated temperatures. The information in this paper is useful for RA manufacturers and mines that may choose to implement a cryogenic air system as a heat mitigation strategy. |
Influence of trailing cables on magnetic proximity detection systems
Zhou C , Li J , Damiano N , DuCarme J , Noll J . Min Metall Explor 2019 36 (2) 277-284 Preventing machine-related injuries is one of the major safety concerns in underground coal mines. Severe injuries and fatalities occur when a miner is struck, crushed, or pinned by mining equipment such as a continuous mining machine (CMM), shuttle car, or a scoop. Proximity detection systems (PDSs) have been applied in mining to reduce these types of injuries and fatalities. All of the PDSs that are currently approved by the Mine Safety and Health Administration (MSHA) for use in underground coal mines are magnetic-field based and could be affected by metallic objects such as trailing cables. Researchers from the National Institute for Occupational Safety and Health (NIOSH) investigated the influence of trailing cables on the performance of PDSs. In particular, the magnetic field coupled from proximity system generators to a de-energized trailing cable were characterized. The results show that significant energy can be coupled from the proximity system generators to a trailing cable when there is a closed loop in the cable. The effect on PDS performance from the magnetic field radiated around an energized trailing cable was also quantified for different current amplitudes in the cable. It is shown that the magnetic field caused by the electric current in the trailing cable mainly consists of a 60-Hz signal and its harmonics which cause little interference to the PDS. The results presented in this paper can help PDS manufacturers to design better systems that are more immune to these effects. |
A test method for evaluating the thermal environment of underground coal mine refuge alternatives
Yantek DS , Yan L , Damiano NW , Reyes MA , Srednicki JR . Int J Min Sci Technol 2019 29 (3) 343-355 Since 2009, the Mine Safety and Health Administration (MSHA) has required mines to install refuge alternatives (RAs) in underground coal mines. One of the biggest concerns with occupied RAs is the possible severity of the resulting thermal environment. In 30 CFR 7.504, the maximum allowable apparent temperature (AT) for an occupied RA is specified as 35 °C (95 °F). Manufacturers must conduct heat/humidity tests to demonstrate that their RAs meet the 35 °C (95 °F) AT limit. For these tests, heat input devices are used to input the metabolic heat of actual miners. A wide variety of test methods, sensors, and heat input devices could be used when conducting such tests. Since 2012, the National Institute for Occupational Safety and Health (NIOSH) has conducted over thirty 96-hour heat/humidity tests on four different RAs. This paper discusses the test equipment and procedures used during these investigations. This information is useful for RA manufacturers conducting RA heat/humidity tests, for other researchers investigating RA heat/humidity buildup, and for those who need to assess the thermal environment of any confined space where people may be trapped or are seeking refuge. |
Industrial Internet of Things: (IIoT) applications in underground coal mines
Zhou C , Damiano N , Whisner B , Reyes M . Min Eng 2017 69 (12) 50-56 The Industrial Internet of Things (IIoT), a concept that combines sensor networks and control systems, has been employed in several industries to improve productivity and safety. U.S. National Institute for Occupational Safety and Health (NIOSH) researchers are investigating IIoT applications to identify the challenges of and potential solutions for transferring IIoT from other industries to the mining industry. Specifically, NIOSH has reviewed existing sensors and communications network systems used in U.S. underground coal mines to determine whether they are capable of supporting IIoT systems. The results show that about 40 percent of the installed post-accident communication systems as of 2014 require minimal or no modification to support IIoT applications. NIOSH researchers also developed an IIoT monitoring and control prototype system using low-cost microcontroller Wi-Fi boards to detect a door opening on a refuge alternative, activate fans located inside the Pittsburgh Experimental Mine and actuate an alarm beacon on the surface. The results of this feasibility study can be used to explore IIoT applications in underground coal mines based on existing communication and tracking infrastructure. |
Simulation and measurement of through-the-earth, extremely low-frequency signals using copper-clad steel ground rods
Damiano NW , Yan L , Whisner B , Zhou C . IEEE Trans Ind Appl 2017 53 (5) 5088-5095 The underground mining environment can greatly affect radio signal propagation. Understanding how the earth affects signal propagation is a key to evaluating communications systems used during a mine emergency. One type of communication system is through-the-earth, which can utilize extremely low frequencies (ELF). This paper presents the simulation and measurement results of recent National Institute for Occupational Safety and Health (NIOSH) research aimed at investigating current injection at ELF, and in particular, ground contact impedance. Measurements were taken at an outside surface testing location. The results obtained from modeling and measurement are characterized by electrode impedance, and the voltage received between two distant electrodes. This paper concludes with a discussion of design considerations found to affect low-frequency communication systems utilizing ground rods to inject a current into the earth. |
Mathematical modeling and measurement of electric fields of electrode-based through-the-earth (TTE) communication
Yan L , Zhou C , Reyes M , Whisner B , Damiano N . Radio Sci 2017 52 (6) 731-742 There are two types of through-the-earth (TTE) wireless communication in the mining industry: magnetic loop TTE and electrode-based (or linear) TTE. While the magnetic loop systems send signal through magnetic fields, the transmitter of an electrode-based TTE system sends signal directly through the mine overburden by driving an extremely low frequency (ELF) or ultralow frequency (ULF) AC current into the earth. The receiver at the other end (underground or surface) detects the resultant current and receives it as a voltage. A wireless communication link between surface and underground is then established. For electrode-based TTE communications, the signal is transmitted through the established electric field and is received as a voltage detected at the receiver. It is important to understand the electric field distribution within the mine overburden for the purpose of designing and improving the performance of the electrode-based TTE systems. In this paper, a complete explicit solution for all three electric field components for the electrode-based TTE communication was developed. An experiment was conducted using a prototype electrode-based TTE system developed by National Institute for Occupational Safety and Health. The mathematical model was then compared and validated with test data. A reasonable agreement was found between them. |
Simulation and measurement of medium-frequency signals coupling from a line to a loop antenna
Damiano NW , Li J , Zhou C , Brocker DE , Qin Y , Werner DH , Werner PL . IEEE Trans Ind Appl 2016 52 (4) 3527-3534 The underground-mining environment can affect radio-signal propagation in various ways. Understanding these effects is especially critical in evaluating communications systems used during normal mining operations and during mine emergencies. One of these types of communications systems relies on medium-frequency (MF) radio frequencies. This paper presents the simulation and measurement results of recent National Institute for Occupational Safety and Health (NIOSH) research aimed at investigating MF coupling between a transmission line (TL) and a loop antenna in an underground coal mine. Two different types of measurements were completed: 1) line-current distribution and 2) line-to-antenna coupling. Measurements were taken underground in an experimental coal mine and on a specially designed surface test area. The results of these tests are characterized by current along a TL and voltage induced in the loop from a line. This paper concludes with a discussion of issues for MF TLs. These include electromagnetic fields at the ends of the TL, connection of the ends of the TL, the effect of other conductors underground, and the proximity of coal or earth. These results could help operators by providing examples of these challenges that may be experienced underground and a method by which to measure voltage induced by a line. |
Medium-frequency signal propagation characteristics of a lifeline as a transmission line in underground coal mines
Li J , Reyes MA , Damiano NW , Whisner BG , Matetic RJ . IEEE Trans Ind Appl 2016 52 (3) 2724-2730 Underground coal mines in the United States of America are required to install lifeline (LL) cable inside escapeways to guide miners out of a mine when visibility becomes poor due to heavy smoke. Some LLs consist of single or multiple steel conductors covered with a protective plastic outer layer. Research has shown that this type of LL can be a good conductor to guide a medium-frequency (MF) communication system signal to travel over large distances. To understand the MF propagation characteristics of an LL, National Institute for Occupational Safety and Health researchers took measurements on a section of LL in a coal mine, and obtained propagation parameters for analysis. The measurement data show that MF signals have a low attenuation which can enable the use of an LL for communication throughout a mine. The propagation parameters measured are presented in this paper. © 2016 IEEE. |
A review of underground coal mine emergency communications and tracking system installations
Damiano N , Homce G , Jacksha R . Coal Age 2014 119 (11) 34-35 The 2006 Mine Improvement and New Emergency Response Act of 2006 (MINER Act) required all underground coal mines in the U.S. to have a plan to provide post-accident communication and electronic tracking for any mine workers trapped underground. | In response, post-accident communications and electronic tracking (emergency CT) technologies designed to meet MINER Act requirements have been developed by various manufacturers and approved for permissibility by the Mine Safety and Health Administration (MSHA), meaning they may be used safely in coal mines that may have gassy or dust-laden atmospheres. As a result, more than a dozen different emergency CT systems have become available for U.S. underground coal mining. | The National Institute for Occupational Safety and Health (NIOSH) recently conducted a review of the latest MSHA-approved Emergency Response Plans (ERPs) for each active underground coal mine on file as of February 2014 to identify and characterize the types of emergency CT systems installed. This review pertains only to CT systems installed underground for emergency purposes, and does not include any CT systems installed or used for non-emergency situations, such as communications for everyday operations. |
An inventory of healthy weight practices in federally funded haemophilia treatment centres in the United States
Adams E , Deutsche J , Okoroh E , Owens-McAlister S , Majumdar S , Ullman M , Damiano ML , Recht M . Haemophilia 2014 20 (5) 639-43 In the haemophilia population, obesity has an adverse effect on health care cost, chronic complications and joint disease. Although staff of federally funded Hemophilia Treatment Centers in the United States (HTCs) anecdotally recognize these outcomes, practices to promote healthy weights have not been reported. This evaluation identifies routine practices among HTCs in body mass index (BMI) assessment, perceptions about need to address obesity and roles in offering evidence-based strategies to promote healthy weights. A telephone survey was developed to assess HTCs practices including patient BMI assessment and counselling, perceptions about the importance of healthy patient weights, and HTCs roles in weight management. Ninety of the 130 federally funded HTCs contacted elected to participate and completed the telephone survey. Of these, 67% routinely calculated BMI and 48% provided results to patients. Approximately one-third classified obesity correctly for children (30%) and adults (32%), using the Centers for Disease Control and Preventions BMI cut-offs. Most HTCs (87%) reported obesity as an issue of 'big' or 'moderate' concern and 98% indicated HTC responsibility to address this issue. Most centres (64%) address patient weight during comprehensive visits. One-third (33%) of centres include a nutritionist; of those without, 61% offer nutrition referrals when needed. Most (89%) HTCs do not have a protocol in place to address healthy weights; 53% indicated that guidelines are needed. HTCs offer services to help improve weight outcomes. Training programmes for calculating and interpreting BMI as well as identifying appropriate guidelines to apply to the HTC patient population are needed. |
NIOSH-sponsored research in through-the-earth communications for mines: a status report
Yenchek MR , Homce GT , Damiano NW , Srednicki JR . IEEE Trans Ind Appl 2012 48 (5) 1700-1707 This paper presents the results of recent contractual research sponsored by the National Institute for Occupational Safety and Health that aimed at demonstrating the feasibility of through-the-earth (TTE) wireless communication in mining. TTE systems, developed by five different contractors, are discussed with a focus on technical approach, prototype hardware, and field test results. System features include both magnetic and electric field sensing, loop and line antennas, digital and analog processing, noise filtering and cancelation, and direction finding. The systems were demonstrated at commercial mine sites. The results of these tests are characterized by transmission range and power levels. This paper concludes with a discussion of issues that remain to be resolved as TTE communications are implemented. These include text versus voice format, acceptable time delays, portability, ease of deployment, an interface with existing communications systems, permissibility, and the effect of geological variations. |
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