Sentences with word «absorptivity»

where Ein = energy absorbed by the surface in J / s, S = the solar irradiance in W / m2, θ = angle of the sun from the zenith, α = absorptivity of the surface at the solar radiation wavelengths.

Note 2 — Emissivity = Absorptivity at a particular wavelength (and direction for «non-diffuse» surfaces).

Therefore the temperature of a body in sunlight may be much higher (like 200C higher) or much lower (like 100C lower) than that of a black or gray body that has equal absorptivity for SW and LW.

For clarity I will use α when specifically talking about absorptivity and ε when specifically talking about emissivity.

Because absorptivity equals emissivity at any wavelength, we know that H2O and CO2 are absorbing the surface emissions at these wavelengths.

The short - and long - wave absorptivities of the most important greenhouse gases water vapour, carbon dioxide, methane and ozone are derived from line - by - line calculations based on the HITRAN08 - databasis and are integrated in the model.

And when emissivity varies while absorptivity is fixed (and therefore absorbed energy is fixed) the temperature T1 is pretty much independent of emissivity for very thin walls — why is that?

So the emissivity and absorptivity vary hugely from one wavelength to the next (note 1).

We report a low - cost, solution - processable solar cell, based on a highly crystalline perovskite absorber with intense visible to near - infrared absorptivity, that has a power conversion efficiency of 10.9 % in a single - junction device under simulated full sunlight.

Furthermore, it is suggested that aerosols with high absorptivity such as black carbon absorb solar radiation in the lower atmosphere, cool the surface, stabilise the atmosphere and reduce precipitation (Ramanathan et al., 2001).

A silvered coating in a vacuum flask has very low Absolute Emissivity and by Kirchhoff's law of Radiation, Absolute Absorptivity.

That means that the emission is the product of an emissivity / absorptivity coefficient (that's where your quantum effects come in) and the Planck function.