Unusual types of gramophone records Hi-Fi was a system of proprietary records and players designed for use in automobiles, utilizing a slower play speed and high stylus pressure. With their origin stretching back to the dawn of recorded sound at the turn of the 20th century, flexible recording media have been made from a variety of materials including foil, paper, and–in the 1950s–thin flexible vinyl known as flexi discs. Thin, flexible paper-based records were briefly popularized in the 1930s by Hit of the Week Records and Durium Records. "Melody Cards" were popular in the late 1950s. They took the form of an oversized rectangular postcard
Polymer interest. These are the properties that dictate how the polymer actually behaves on a macroscopic scale. The tensile strength of a material quantifies how much elongating stress the material will endure before failure. This is very important in applications that rely upon a polymer's physical strength or durability. For example, a rubber band with a higher tensile strength will hold a greater weight before snapping. In general, tensile strength increases with polymer chain length and crosslinking of polymer chains. Young's modulus quantifies the elasticity of the polymer. It is defined, for small strains, as the ratio of rate of change