Dr. Lester W. Schmerr Jr. is Professor Emeritus, Iowa State University. He is the author of two books on Ultrasonic Non-destructive Evaluation and has published six other books on Ultrasonic Phased Arrays, Engineering Statics, Engineering Dynamics, Advanced Mechanics of Solids, Algebraic Equations of Linear Elasticity, and MATLAB Essentials. He is the author or co-author of over 180 papers, primarily in the field of ultrasonics.