Process control systems in a chemical plant or oil refinery maintain fluid levels, pressures, temperature, chemical composition, etc. by controlling heaters, pumps and valves. [citation needed] The centrifugal governor of a steam engine, as designed by James Watt in 1788, reduces the throttle valve in response to increases in the engine speed, or opens the valve if the speed falls below the pre-set rate.
Collagen is made from dietary proteins. As a structural protein, collagen builds connective tissues found throughout your body. While it's essential for tendons and ligaments, collagen does much more than that: It supports soft tissues such as organs, gives resilience to bones and keeps your skin firm. It can fill such diverse jobs thanks to a chain-like structure that can form long filaments and crisscross into sheets of connective tissue.
Collagen occurs throughout the body, but especially in the skin, bones, and connective tissues. Some types of collagen fibrils, gram-for-gram, are stronger than steel. Collagen production declines with age and exposure to factors such as smoking and UV light. Collagen can be used in collagen dressings, to attract new skin cells to wound sites. Cosmetic lotions that claim to increase collagen levels are unlikely to do so, as collagen molecules are too large to be absorbed through the skin.