An antenna includes a first antenna element, a second antenna element, and a third antenna element. Further, the concavities separately located adjacent to the screw head and to the drilling portion are disposed at relative positions for aligning with an imaginary line, hence efficiently cutting and severing the object fibers to enhance a screwing efficiency. The method utilizes catalyzed ring opening polymerization of the N-carboxyanhydride of the amino acid-imaging agent monomer allowing the formation of a poly backbone having 100% imaging agent conjugation if desired. Also provided are methods of making and using the hydraulic cements, as well as settable compositions, such as concretes and mortars, prepared therefrom. A controller and an ACDC converter operable according to such a method are also disclosed as is an LED lighting system comprising such a controller.