A Method for Estimating the Low Frequency Coupling Characteristics of a Ferrite-Cored Rod Antenna to a Long Conductor.

Magnetic proximity detection systems (PDSs) used in underground mines occasionally generate false alarms when the miner-wearable component (MWC) is close to nearby conductors such as power cables. This is because the signals from the generators (antennas) of the PDS wirelessly couple to nearby cables, travel along these cables, and then couple back from the cable to a distant MWC to cause a false alarm. In order to manage such a false alarm, it is necessary to understand the basic near-field coupling characteristics from a generator to a long wire.

Field assessment of enclosed cab filtration system performance using particle counting measurements.

Enclosed cab filtration systems are typically used on mobile mining equipment to reduce miners' exposure to airborne dust generated during mining operations. The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has recently worked with a mining equipment manufacturer to examine a new cab filtration system design for underground industrial minerals equipment. This cab filtration system uses a combination of three particulate filters to reduce equipment operators' exposure to dust and diesel particulates present in underground industrial mineral mines.

Evaluating portable infrared spectrometers for measuring the silica content of coal dust.

Miners face a variety of respiratory hazards while on the job, including exposure to silica dust which can lead to silicosis, a potentially fatal lung disease. Currently, field-collected filter samples of silica are sent for laboratory analysis and the results take weeks to be reported. Since the mining workplace is constantly moving into new and often different geological strata with changing silica levels, more timely data on silica levels in mining workplaces could help reduce exposures.

Sampling results of the improved SKC diesel particulate matter cassette.

Diesel particulate matter (DPM) samples from underground metal/nonmetal mines are collected on quartz fiber filters and measured for carbon content using National Institute for Occupational Safety and Health Method 5040. If size-selective samplers are not used to collect DPM in the presence of carbonaceous ore dust, both the ore dust and DPM will collect on the quartz filters, causing the carbon attributed to DPM to be artificially high. Because the DPM particle size is much smaller than that of mechanically generated mine dust aerosols, it can be separated from the larger mine dust aerosol by a single-stage impactor.

Evaluation of the SKC DPM cassette for monitoring diesel particulate matter in coal mines.

In a previous study, the efficacy of commercial and prototype impactors for sampling diesel particulate matter (DPM) in coal mines was investigated. Laboratory and field samples were collected on quartz-fiber filters and analyzed for organic and elemental carbon. Coal dust contributed a minimal amount of elemental carbon when commercial cascade impactors and prototype impactors, designed by the University of Minnesota (UMN) and the US Bureau of Mines (BOM), were used to collect submicrometer dust fractions.

Submicrometer elemental carbon as a selective measure of diesel particulate matter in coal mines.

A monitoring method for diesel particulate matter was published as Method 5040 by the National Institute for Occupational Safety and Health (NIOSH). Organic and elemental carbon are determined by the method, but elemental carbon (EC) is a better exposure measure. The US Mine Safety and Health Administration (MSHA) proposed use of NIOSH 5040 for compliance determinations in metal and nonmetal mines.