Mealey's (February 24, 2016, 11:46 AM EST) -- PITTSBURGH — While a professor may testify as to the installation and removal of a trash conveyor and whether the conveyor had moved, he may not testify as to the necessity and value of the conveyor, a Pennsylvania federal judge ruled Feb. 22, granting and denying in part a motion to exclude testimony in a defective design lawsuit against manufacturers of the conveyor (Brandi L. McKenzie v. Dematic Corp., et al., No. 12-250, W.D. Pa.; 2016 U.S. Dist. LEXIS 21256)....