(T) The system international (SI) unit of magnetic flux density. Definition: 1 T is the field intensity generating 1 N (newton) of force per ampere of current per meter of conductor. The tesla unit value is defined as a field strength of 1 weber per square meter of area, where 1 weber represents 1 x 10⁸ (100 000 000) flux lines. One T is equal to 10 000 gauss, the older (CGS) unit. A field of 1 tesla is quite strong, the Earth's magnetic flux density, at its surface, is about 50 microteslas (µT).

Slow neutrons have a speed of around 2.2 km/s (0.025 eV). They could be generated in a reactor and could lead, because of their much larger effective neutron absorption cross-section than quick neutrons, to neutron activation.

See also Neutron Activation, Neutron Activation Analysis, Neutron Capture and Neutron Radiation.

(BTU/Hr) BTU/Hr is a common measure of heat transfer rate. Capacities of furnaces and boilers are for example expressed in thermal units per hour (British unit). One BTU/Hr is the amount of heat required to heat one pound of water one degree Fahrenheit per hour.
BTU/Hr is the unit that expresses how much a machine heats up the surrounding area.

Thermography is a method for example used in breast imaging. Thermography measures the body heat at the skin surface to identify hot spots caused by inflammation or cancer.

(TLD) A thermoluminescent dosimeter contains a crystalline material (lithium fluoride, phosphor) for measuring radiation dose. TLDs are usually small crystals measuring 3 mm square by 1 mm thickness. Additional filters (absorbers) help to characterize the types of the impinging radiation. When heated, TLD crystals that have been exposed to ionizing radiation give off light proportional to the received energy.