Embolic implants and methods of manufacture are disclosed. The reactor produces a biofuel product. The composition achieves high-efficiency removal of such material in the manufacture of integrated circuitry without adverse effect on metal species on the substrate, such as copper, and without damage to SiOC-based dielectric materials employed in the semiconductor architecture. When a special symbol is carried by a symbol-carrying element into a display position on the display, the special symbol does at least one of altering the prize awarded for a winning result and altering a defined set of winning combinations. A stiffener is attached to the load beam in a multi-layered structure. The exterior of the bit preferably includes a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the bit against the bottom of the borehole without exceeding the compressive strength of the formation rock.