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The SI unit of absolute thermal resistance is kelvins per watt (K/W) or the equivalent degrees Celsius per watt (°C/W) – the two are the same since the intervals are equal: ΔT = 1 K = 1 °C. The thermal resistance of materials is of great interest to electronic engineers because most electrical components generate heat and need to be cooled.
These thermal greases have low electrical conductivity and their volume resistivities are 1.5⋅10 15, 1.8⋅10 11, and 9.9⋅10 9 Ω⋅cm for 860, 8616 and 8617 respectively. The thermal grease 860 is a silicone oil with a Zinc Oxide filler and 8616 and 8617 are synthetic oils with various fillers including Aluminum Oxide and Boron Nitride.
Some papers report in watts per centimeter-kelvin [W/(cm⋅K)]. However, physicists use other convenient units as well, e.g., in cgs units , where esu/(cm-sec-K) is used. [ 13 ] The Lorentz number , defined as L=κ/σT is a quantity independent of the carrier density and the scattering mechanism.
Electric potential: φ: Energy required to move a unit charge through an electric field from a reference point volt (V = J/C) L 2 M T −3 I −1: extensive, scalar Electrical resistance: R: Electric potential per unit electric current ohm (Ω = V/A) L 2 M T −3 I −2: extensive, scalar, assumes linearity Electrical resistivity: ρ e
watt per square meter (W/m 2) sound intensity: watt per square meter (W/m 2) electric current: ampere (A) moment of inertia: kilogram meter squared (kg⋅m 2) intensity: watt per square meter (W/m 2) imaginary unit: unitless electric current: ampere (A) ^ Cartesian x-axis basis unit vector unitless
SI derived units are units of measurement derived from the seven SI base units specified by the International System of Units (SI). They can be expressed as a product (or ratio) of one or more of the base units, possibly scaled by an appropriate power of exponentiation (see: Buckingham π theorem).
The kelvin now only depends on the Boltzmann constant and universal constants (see 2019 SI unit dependencies diagram), allowing the kelvin to be expressed exactly as: [2] 1 kelvin = 1.380 649 × 10 −23 / (6.626 070 15 × 10 −34)(9 192 631 770) h Δν Cs / k B = 13.806 49 / 6.091 102 297 113 866 55 h Δν Cs / k B
As quoted in an online version of: David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition.CRC Press. Boca Raton, Florida, 2003; Section 4, Properties of the Elements and Inorganic Compounds; Physical Properties of the Rare Earth Metals