Carbon fiber reinforced polymer as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The composite material may contain aramid (e.g. Kevlar, Twaron), ultra-high-molecular-weight polyethylene (UHMWPE), aluminium, or glass fibers in addition to carbon fibers. The properties of the final CFRP product can also be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other additives such as rubber and carbon nanotubes can be used. The material is also referred to as "graphite-reinforced polymer" or "graphite fiber-reinforced polymer" ("GFRP" is less common, as it clashes with
Sometimes I'm Happy (Sometimes I'm Blue) Sometimes I'm Happy (Sometimes I'm Blue) "Sometimes I'm Happy" is a popular song. The music was written by Vincent Youmans, the lyrics by Irving Caesar. The song was published in 1927 and introduced in the Broadway musical "Hit the Deck," starring Stanley Holloway, and opened in April 1927. The song was performed in the musical by Charles King and Louise Groody, who also made a recording for Victor Records, catalog number 20609. The best-selling versions were by King and Groody and by Roger Wolfe Kahn (with vocal by Franklyn Baur), also issued by Victor (catalog number 20599). Two other versions,