Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-4 (of 4 Records) |
Query Trace: Srednicki JR[original query] |
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Cryogenic air supply feasibility for a confined space: Underground refuge alternative case study
Yan L , Yantek DS , DeGennaro CR , Srednicki JR , Lambie B , Carr J . ASME J Heat Mass Transf 2024 146 (3) A breathable air source is required for a confined space such as an underground refuge alternative (RA) when it is occupied. To minimize the risk of suffocation, federal regulations require that mechanisms be provided and procedures be included so that, within the refuge alternative, the oxygen concentration is maintained at levels between 18.5% and 23% for 96 h. The regulation also requires that, during use of the RA, the concentration of carbon dioxide should not exceed 1%, and the concentration of carbon monoxide should not exceed 25 ppm. The National Institute for Occupational Safety and Health (NIOSH) evaluated the cryogenic air supply's ability to provide breathable air for a refuge alternative. A propane smoker was used to simulate human breathing by burning propane gas which will consume O(2) and generate CO(2) and H(2)O. The rate of propane burned at the smoker was controlled to represent the O(2) consumption rate for the breathing of a certain number of people. Two 96-h tests were conducted in a sealed shipping container, which was used as a surrogate for a refuge alternative. While burning propane gas to simulate human oxygen consumption, cryogenic air was provided to the shipping container to determine if the cryogenic air supply would keep the O(2) level above 18.5% and CO(2) level below 1% inside the shipping container as required by the federal regulations pertaining to refuge alternatives. Both of the 96-h tests simulated the breathing of 21 persons. The first test used the oxygen consumption rate (1.32 cu ft of pure oxygen per hour per person) specified in federal regulations, while the second test used the oxygen consumption rate specified by (Bernard et al. 2018, "Estimation of Metabolic Heat Input for Refuge Alternative Thermal Testing and Simulation," Min. Eng., 70(8), pp. 50-54) (0.67 cu ft of pure oxygen per hour per person). The test data shows that during both 96-h tests, the oxygen level was maintained within a 21-23% range, and the CO(2) level was maintained below 1% (0.2-0.45%). The information in this paper could be useful when applying a cryogenic air supply as a breathable air source for an underground refuge alternative or other confined space. [DOI: 10.1115/1.4064062]. |
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. |
Comparative evaluation of light-emitting diode cap lamps with an emphasis on visual performance in mesopic lighting conditions
Reyes MA , Sammarco JJ , Gallagher S , Srednicki JR . IEEE Trans Ind Appl 2014 50 (1) 127-133 Conducted at the National Institute for Occupational Safety and Health's (NIOSH) Office of Mine Safety and Health Research, the experiment described in this paper is part of ongoing mine illumination research designed to explore the benefits of solid-state lighting technologies when applied to the underground mining industry. This experiment involves the comparative evaluation of cap lamps with similar spectral power distributions, focusing on the electrical and battery discharge characteristics, with a secondary objective being the benefits gained through alternative light beam distributions. NIOSH researchers conducted the investigation by comparing three commercially available light-emitting diode cap lamps and an NIOSH prototype cap lamp at varying power settings. Visual performance for the detection of hazards was quantified by recording times of detection for finding rotating targets in the peripheral field of view and objects representing trip and fall hazards on the ground. The NIOSH prototype cap lamp resulted in improvements ranging from 15% to 43% for peripheral motion detection time and 5%-23% for slip, trip, and fall object detection time, respectively, as compared with the referent incandescent cap lamp. 1972-2012 IEEE. |
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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