The systemic circulation is the portion of the circulatory system is the network of veins, arteries and blood vessels that transports blood from heart, services the body's cells and then re-enters the heart, the Mayo Clinic noted. [Image Gallery: The BioDigital Human]
A southern pine (2) 2x12 beam can span 8 feet when supporting joists spanning a maximum of 14 feet, and it can cantilever 2 feet beyond the posts on each side. With the allowable cantilever of the joists, this beam would support a deck 12 feet by 17 1/2 feet.
These are usually placed 16 inches from centers, except for floors which are to carry very heavy weights. In these the joists are frequently placed 12 inches from centers. To estimate them 12 inches from centers add 1 to the number of feet in length of one wall on which the joists are placed.For example, suppose a building is 32 feet long, and the joists are placed 12 inches from centers.We simply add 1 to 32, which makes 33 the number of joists required for one span.f the spans are unlike, then estimate each span separately. If the joists are placed 16 inches from centers, then multiply the length of wall by Â½ and add 1. This will give the required number. Thus if the wall is 32 feet long, then 32 x Â½ + 1 = 25, he number required for one span.