psi

The twenty-third letter of Classical and Modern Greek and the twenty-fifth letter of Old and Ancient Greek.

A form of psychic energy.

‘Come, lad,’ he said. ‘We will take tea together and speak of the noumenon, the psi and other more heterogenous phenomena.’

When an event is classified as a psi phenomenon, it is claimed that all known channels for the apparent interaction have been eliminated.

Pound per square inch (an imperial unit of pressure)

Each turbogenerator consisted of a steam turbine, powered by 900 psi of superheated steam, that was coupled by a set of reduction gears to a General Electric marine alternating-current generator operating at 1,800 rpm. Each generator had a capacity of 2,000 kilowatts of three-phase power at 450 volts and 60 hertz. The main 450-volt switchboard was energized by the two turbogenerators. The emergency switchboard, in the emergency generator room, was fed from the main switchboard through an electrical tie.

For M2, this is typically around 3250 MPa (471,000 psi) when tempered at 300°F (149°C).

Initialism of pre-sentence investigation.

Initialism of protein structure initiative.

Initialism of pollutant safety/standard index (measurement of the air pollutant such as haze).