A method for making a ball-nut includes cutting a 360-degree closed-loop surface groove in the inner-circumferential wall portion of a ball-nut body using a whirling-type internal-diameter cutting machine. These novel compounds inhibit the processing of amyloid precursor protein and, more specifically, inhibit the production of A\u03b2-peptide, thereby acting to prevent the formation of neurological deposits of amyloid protein. The diaphragm may have one or more ribs for seating against other portions of the body located around the passage. The mixture may optionally include a sweetener, such as sugar, stevia, or the like. In one aspect, said silica aggregates may be pre-treated to reduce said hydroxyl groups on their surface prior to blending with said silanol andor siloxy functionalized elastomer.