Parsec but in globular clusters the stellar density could be from 100 to 1000 per cubic parsec. Parsec The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System. A parsec is defined as the distance at which one astronomical unit subtends an angle of one arcsecond, which corresponds to astronomical units. One parsec is equal to about 3.26 light-years (30 trillion km or 19 trillion miles) in length. The nearest star, Proxima Centauri, is about from the Sun. Most of the stars visible to the unaided eye in the night
PC strand T 5224, American Standard ASTM A416, British standard BS 5896 and the Japanese standard JIS G3536, the Australian standard AS / NZS 4672, Brazilian standard NBR-7483 3, http://www.pcstrand.cn/f694801/What's-PC-STRAND.htm PC strand PC Strand, or prestressed concrete steel strand, is a twisted steel cable composed of 2, 3, 7 or 19 high strength steel wires and is stress-relieved (stabilized) for prestressed concrete or similar purposes. PC strand is classified according to the number of steel wires in a strand: 2 wire strand, 3 wire strand, 7 wire steel strand and 19 wire steel strand. It can be classified according to the surface