Mathematics

The vector stencils library "Hydraulic pumps and motors" contains 74 symbols of hydraulic pump vector stencils, hydraulic motor symbols for engineering drawings of fluid power and hydraulic control systems.
"Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic.
Hydrostatic pumps are positive displacement pumps while hydrodynamic pumps can be fixed displacement pumps, in which the displacement (flow through the pump per rotation of the pump) cannot be adjusted, or variable displacement pumps, which have a more complicated construction that allows the displacement to be adjusted." [Hydraulic pump. Wikipedia]
"A hydraulic motor is a mechanical actuator that converts hydraulic pressure and flow into torque and angular displacement (rotation). The hydraulic motor is the rotary counterpart of the hydraulic cylinder.
Conceptually, a hydraulic motor should be interchangeable with a hydraulic pump because it performs the opposite function - much as the conceptual DC electric motor is interchangeable with a DC electrical generator. However, most hydraulic pumps cannot be used as hydraulic motors because they cannot be backdriven. Also, a hydraulic motor is usually designed for the working pressure at both sides of the motor.
Hydraulic pumps, motors, and cylinders can be combined into hydraulic drive systems. One or more hydraulic pumps, coupled to one or more hydraulic motors, constitutes a hydraulic transmission." [Hydraulic motor. Wikipedia]
The shapes example "Design elements - Hydraulic pumps and motors" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Mechanical Engineering solution from the Engineering area of ConceptDraw Solution Park.

The vector stencils library "Lamps, acoustics, readouts" contains 35 element symbols of lamps, acoustic components, electrical measuring instruments for drawing electrical schematics and electronic circuit diagrams.
"Electrical measurements are the methods, devices and calculations used to measure electrical quantities. Measurement of electrical quantities may be done to measure electrical parameters of a system. Using transducers, physical properties such as temperature, pressure, flow, force, and many others can be converted into electrical signals, which can then be conveniently measured and recorded." [Electrical measurements. Wikipedia]
"A lamp is a replaceable component such as an incandescent light bulb, which is designed to produce light from electricity." [Lamp (electrical component). Wikipedia]
"An electric bell is a mechanical bell that... functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing or clanging sound." [Electric bell. Wikipedia]
"A buzzer or beeper is an audio signalling device, which may be mechanical, electromechanical, or piezoelectric." [Buzzer. Wikipedia]
"Electronic sirens incorporate circuits such as oscillators, modulators, and amplifiers to synthesize a selected siren tone (wail, yelp, pierce/ priority/ phaser, hi-lo, scan, airhorn, manual, and a few more) which is played through external speakers." [Siren (noisemaker). Wikipedia]
"A microphone (colloquially called a mic or mike...) is an acoustic-to-electric transducer or sensor that converts sound in air into an electrical signal. ...
Most microphones today use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone) or piezoelectric generation to produce an electrical signal from air pressure variations." [Microphone. Wikipedia]
The symbols example "Design elements - Lamps, acoustics, readouts" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.