Abstract: A device for comminuting whole trees or brush type vegetation comprising a set of more than two rotatable substantially horizontally oriented comminution drum assemblies; said set of rotatable comminution drum assemblies being constructed and arranged in an angular orientation so that the uppermost rotatable comminution drum assembly in said set of more than two substantially horizontally oriented comminution drum assemblies first engages the top portion of the whole tree or brush type vegetation and the remaining rotatable comminution drum assemblies in said set of more than two substantially horizontally oriented comminution drum assemblies sequentially engage lower portions of the whole tree or brush type vegetation that exist immediately below the portions that are comminuted by each successive comminution drum assembly.

Abstract: A system and method are described for rendering Compact Discs (CDs) and Digital Video Discs (DVDs) unreadable. Embodiments comprise a frame, a guide for constraining motion of the frame with respect to a disc, and at least one scraping element. Scraping elements may be positioned to damage the disc volume descriptor while the frame moves in a constrained manner relative to the disc. The guide may comprise a spindle which engages the center hole of a disc to hold the frame in a radially-fixed position. A scraping element on the frame damages the disc as the disc rotates relative to the frame. The guide may be integrated, such that the frame comprises a slot through which the disc passes. A scraping element inside the slot damages a disc as it passes through. Embodiments are hand operated, not motorized, and some have no moving parts. Embodiments also function with non-optical media.

Abstract: A doctor blade assembly has a doctor blade supported in a blade holder. The blade has a projecting front edge adapted to be placed in contact with a moving surface to be doctored, and a rear edge adapted to be received in the blade holder. The blade is preloaded in a manner such that tensile stresses are induced in the front edge thereof. The level of such tensile stresses is below the yield strength of the blade material, yet high enough to prevent compressive stresses from developing at the blade front edge as a result of heat being generated by frictional contact between the blade and the moving surface being doctored.