SCR

SCR is an acronym that can refer to several distinct concepts across technology, regulation, and infrastructure.

Silicon Controlled Rectifier (SCR) is a four-layer, three-terminal semiconductor device that functions as a latchable switch. When a small gate signal is applied, the device conducts current in one direction and remains on until the current falls below a holding value. SCRs are used in controlled rectifiers, motor drives, and power supplies to regulate high power with a relatively small control signal.

Selective Catalytic Reduction (SCR) is an exhaust aftertreatment technique used to reduce nitrogen oxide emissions from diesel and lean-burn engines. In an SCR system, a reductant such as urea or ammonia is injected into the exhaust and reacts on a catalyst to form nitrogen and water. SCR is a common component of modern emissions-control strategies in on-road and non-road applications.

Solvency Capital Requirement (SCR) is a risk-based capital standard under Solvency II for insurance and reinsurance companies. It represents the amount of capital needed to cover substantial risks over a one-year period, calculated using standard formulas or internal models. Regulators monitor SCR to assess the financial resilience of insurers.

.scr is a file extension used by Windows for screensaver programs. Such files are executable and may be run by the operating system when a screensaver is active; they can be legitimate or potentially misused as malware, so caution is advised when opening unfamiliar .scr files.

South Central Railway (SCR) is a zone of Indian Railways. It operates a network in parts of central and southern India and serves passenger and freight traffic with multiple divisions and routes.