A buffer conveyor for conveying and buffering products comprises a first and a second conveyor, which move at least substantially parallel to each other in helical paths about a common vertical axis, albeit in opposite directions. The first wall, second wall and the third wall form a U-shaped channel dimensioned to fit around the bottom of a door having a thickness less than about 2 inches. Also provided is a method of forming the dual damascene interconnect structure. This effect makes the broadband antenna apparatus smaller and lower in structure. A resonator which suppresses pressure pulses within the inlet duct is mounted to the intake manifold system, but fluidically connected to the air inlet duct, and not to the intake manifold system. A dendrimer useful in the synthesis of the fractal-like compound includes a single ligating moiety bound to a surface of each quadrant of the dendrimer.