Frictional Ignition of Natural Gas-air Mixtures by Alternative Coal-cutter Bit Shank Materials

by Ann G. Kim, August J. Kwitowski, D. D. Harbuck, David H. Carlson, J. E. Chilton, Jeffrey Shawn Peterson, John A. Organiscak, L. Garner McDonald, Michael J. Friedel, Richard A. Allwes, Thomas M. Barczak, Yael Miron, Albert L. Brautigam, C. P. Mangelsdorf, Charles P. Lazzara, Clarence R. Carpenter, David F. Gearhart, James A. Jessop, Steven J. Page, Thomas R. Justin, Todd R. Taubert, Alex C. Smith, John F. Miller, John H. Johnson, Michael C. Leigh, Richard E. Thill, Robert A. Jankowski · 1992