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  2. Effective temperature - Wikipedia

    en.wikipedia.org/wiki/Effective_temperature

    The effective temperature of the Sun (5778 kelvins) is the temperature a black body of the same size must have to yield the same total emissive power.. The effective temperature of a star is the temperature of a black body with the same luminosity per surface area (F Bol) as the star and is defined according to the Stefan–Boltzmann law F Bol = σT eff 4.

  3. Heat index - Wikipedia

    en.wikipedia.org/wiki/Heat_index

    The heat index (HI) is an index that combines air temperature and relative humidity, in shaded areas, to posit a human-perceived equivalent temperature, as how hot it would feel if the humidity were some other value in the shade. For example, when the temperature is 32 °C (90 °F) with 70% relative humidity, the heat index is 41 °C (106 °F ...

  4. Stefan–Boltzmann law - Wikipedia

    en.wikipedia.org/wiki/Stefan–Boltzmann_law

    The temperature Stefan obtained was a median value of previous ones, 1950 °C and the absolute thermodynamic one 2200 K. As 2.57 4 = 43.5, it follows from the law that the temperature of the Sun is 2.57 times greater than the temperature of the lamella, so Stefan got a value of 5430 °C or 5700 K. This was the first sensible value for the ...

  5. Thermal comfort - Wikipedia

    en.wikipedia.org/wiki/Thermal_comfort

    The SET index is defined as the equivalent dry bulb temperature of an isothermal environment at 50% relative humidity in which a subject, while wearing clothing standardized for activity concerned, would have the same heat stress (skin temperature) and thermoregulatory strain (skin wettedness) as in the actual test environment.

  6. Table of thermodynamic equations - Wikipedia

    en.wikipedia.org/wiki/Table_of_thermodynamic...

    Quantity (common name/s) (Common) symbol/s Defining equation SI unit Dimension Temperature gradient: No standard symbol K⋅m −1: ΘL −1: Thermal conduction rate, thermal current, thermal/heat flux, thermal power transfer

  7. Operative temperature - Wikipedia

    en.wikipedia.org/wiki/Operative_temperature

    Operative temperature is used in heat transfer and thermal comfort analysis in transportation and buildings. [10] Most psychrometric charts used in HVAC design only show the dry bulb temperature on the x-axis(abscissa), however, it is the operative temperature which is specified on the x-axis of the psychrometric chart illustrated in ANSI/ASHRAE Standard 55 – Thermal Environmental Conditions ...

  8. Planetary equilibrium temperature - Wikipedia

    en.wikipedia.org/wiki/Planetary_equilibrium...

    For example, Venus has an effective temperature of approximately 226 K (−47 °C; −53 °F), but a surface temperature of 740 K (467 °C; 872 °F). [ 13 ] [ 14 ] Similarly, Earth has an effective temperature of 255 K (−18 °C; −1 °F), [ 14 ] but a surface temperature of about 288 K (15 °C; 59 °F) [ 15 ] due to the greenhouse effect in ...

  9. Gouy–Stodola theorem - Wikipedia

    en.wikipedia.org/wiki/Gouy–Stodola_theorem

    The modified theorem then reads ˙ = ˙ where is the effective temperature. For a flow process, let s 1 {\displaystyle s_{1}} denote the specific entropy (entropy per unit mass) at the inlet, where mass flows in, and s 2 {\displaystyle s_{2}} the specific entropy at the outlet, where mass flows out.