Biodegradable polymer which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost. Biodegradable polymers have a long history, and since many are natural products, the precise timeline of their discovery and use cannot be accurately traced. One of the first medicinal uses of a biodegradable polymer was the catgut suture, which dates back to at least 100 AD. The first catgut sutures were made from the intestines of sheep, but modern catgut sutures are made from purified collagen extracted from the small intestines of cattle, sheep, or goats. The concept of synthetic
Musical instrument the twentieth century saw the gradual evolution of synthesizers—instruments that artificially produce sound using analog or digital circuits and microchips. In the late 1960s, Bob Moog and other inventors began an era of development of commercial synthesizers. One of the first of these instruments was the Moog synthesizer. The modern proliferation of computers and microchips has spawned an entire industry around electronic musical instruments. There are many different methods of classifying musical instruments. Various methods examine aspects such as the physical properties of the instrument (material, color, shape, etc.), the use for the instrument, the means by which music is