Roller chain or bush roller chain is the type of chain drive most commonly used for transmission of mechanical power on many kinds of domestic, industrial and agricultural machinery, including conveyors, wire- and tube-drawing machines, printing presses, cars, motorcycles, and bicycles.
Pietra dura (Italian: [ËpjÉËtra ËduËra]) or pietre dure [ËpjÉËtre ËduËre] (see below), called parchin kari or parchinkari in South Asia, is a term for the inlay technique of using cut and fitted, highly polished colored stones to create images. It is considered a decorative art.
Triquetra means âtriangleâ or âthreeâ (tri-) âcorneredâ (quetrus). It is made up of three intersecting vesicae piscis.A vesica piscis in turn is the shape created by the intersection of two congruent circles. A triquetra symbol is sometimes interlaced with a circle.riquetra means âtriangleâ or âthreeâ (tri-) âcorneredâ (quetrus). It is made up of three intersecting vesicae piscis.