Pneumatic actuator Pneumatic actuator A pneumatic control valve actuator converts energy (typically in the form of compressed air) into mechanical motion. The motion can be rotary or linear, depending on the type of actuator. A Pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Valves require little pressure to operate and usually double or "triple" the input force. The larger the size of the piston,
The Work of Art in the Age of Mechanical Reproduction free", for lacking the "aura" of the original work of art. The Work of Art in the Age of Mechanical Reproduction The Work of Art in the Age of Mechanical Reproduction (1935, "Das Kunstwerk im Zeitalter seiner technischen Reproduzierbarkeit"), by Walter Benjamin, is an essay of cultural criticism which proposes that the "aura" of a work of art is devalued by mechanical reproduction. The subject and themes of the essay have much influenced the fields of art history and architectural theory, and of cultural studies and media theory. During the Nazi régime (1933–1945) in Germany, Benjamin wrote the essay to