Canopy air curtain (CAC) technology has been developed by the National Institute for Occupational Safety and Health (NIOSH) for use on continuous miners and subsequently roof bolting machines in underground coal mines to protect operators of these machines from overexposure to respirable coal mine dust. The next logical progression is to develop a CAC for shuttle cars to protect operators from the same overexposures. NIOSH awarded a contract to Marshall University and J.H. Fletcher to develop the shuttle car CAC. NIOSH conducted laboratory testing to determine the dust control efficiency of the shuttle car CAC. Testing was conducted on two different cab configurations: a center drive similar to that on a Joy 10SC32AA cab model and an end drive similar to that on a Joy 10SC32AB cab model. Three different ventilation velocities were tested—0.61, 2.0, 4.3 m/s (120, 400, and 850 fpm). The lowest, 0.61 m/s (120 fpm), represented the ventilation velocity encountered during loading by the continuous miner, while the 4.3 m/s (850 fpm) velocity represented ventilation velocity airflow over the shuttle car while tramming against ventilation airflow. Test results showed an average of the dust control efficiencies ranging from 74 to 83% for 0.61 m/s (120 fpm), 39%–43% for 2.0 m/s (400 fpm), and 6%–16% for 4.3 m/s (850 fpm). Incorporating an airflow spoiler to the shuttle car CAC design and placing the CAC so that it is located 22.86 cm (9 in.) forward of the operator improved the dust control efficiency to 51%–55% for 4.3 m/s (850 fpm) with minimal impact on dust control efficiencies for lower ventilation velocities. These laboratory tests demonstrate that the newly developed shuttle car CAC has the potential to successfully protect shuttle car operators from coal mine respirable dust overexposures.

This paper presents a nondestructive testing method to measure the depths of the penetration of preservatives in treated wood. It also shows that it is feasible to correlate impedance changes in an eddy current response with the physical characteristics of chemically processed wood. Experimentally this will be a accomplished by using the eddy current test system at varying frequencies to collect data (impedance changes of the test probe) from test samples having different concentrations and depths of penetration of preservatives. This data will be used to show the correlation between impedance changes due to variations in the penetration and concentration of preservatives in treated wood.

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Steady laminar boundary layer flow and heat transfer of a micropolar fluid over a heated isothermal horizontal plate moving in a flowing stream has been studied in this paper. The cases corresponding to the isothermal horizontal plate moving in the same (parallel) or in the opposite (reverse) direction to the free stream are considered. Similarity and nonsimilarity equations of six special systems are reduced readily from universal formulation. The governing momentum, angular momentum, and energy equations have been solved numerically. The effects of buoyancy and relative velocity on the flow and temperature fields including surface friction and heat transfer rate are presented for a plate moving in parallel or reversely to the free stream. It is observed that micropolar fluids display drag reduction when compared to Newtonian fluids.