this paper investigates the radiative absorptivity of a spherical cavity by using monte carlo techniques. several parameters such as the angle of incoming radiation which inters the cavity for both diffuse wall cavity and specular wall cavity has been  investigated. the absorptivity of a spherical cavity has been calculated and compared with the exact values when the angle of incoming radiation...

Proton acceleration from nanometer thin foils with intense laser pulses is investigated experimentally. We analyzed the laser absorptivity by parallel monitoring of laser transmissivity and reflectivity with different laser intensities when moving the targets along the laser axis. A direct correlation between laser absorptivity and maximum proton energy is observed. Experimental results are int...

We estimate high optical absorption in silicon thin film photovoltaic devices using triangular corrugations on the back metallic contact. We computationally show 21.9% overall absorptivity in a 100-nm-thick silicon layer, exceeding any reported absorptivity using single layer gratings placed on the top or the bottom, considering both transverse electric and transverse magnetic polarizations and...

Thermal management systems for space equipment commonly use static solutions that do not adapt to environmental changes. Dynamic control of radiative surface properties is one way to respond to environmental changes and to increase the capabilities of spacecraft thermal management systems. This paper documents an investigation of the extent to which origamiinspired surfaces may be used to contr...

[1] In the context of climate feedback associated with temperature change, there exist two potential mechanisms that affect the outgoing longwave radiation (OLR) and the downward longwave radiation (DLR). One is the ‘‘Planck’’ effect that determines the blackbody thermal emission at a considered temperature. The other is the ‘‘absorptivity’’ effect, in which a temperature change causes a change...

A stable stock solution of bilirubin in chloroform may be used to standardize quantitative determination of bilirubin in serum as “azobilirubin.” The molar absorptivity of azobilirubin (560 mj, 1 cm.) is 70,300 ± 280 (mean ± I S.D.) when determined from chloroform-methanol standards treated with a modified van den Bergh reagent in the Malloy and Evelyn procedure for total bilirubin. The absorpt...

We describe a method for calculating the absorptivity (in terms of substrate consumed) of the colored solution obtained when o-dianisidine dihydrochloride is oxidized by ceruloplasmin. By oxidizing o-dianisidine dihydrochloride with known amounts of hydrogen peroxide we could determine that the molar reacting ratio of o-dianisidine to hydrogen peroxide is 2:1. So calculated, absorptivity is 9.6...

In this Letter we demonstrate, for the first time, selective thermal emitters based on metamaterial perfect absorbers. We experimentally realize a narrow band midinfrared (MIR) thermal emitter. Multiple metamaterial sublattices further permit construction of a dual-band MIR emitter. By performing both emissivity and absorptivity measurements, we find that emissivity and absorptivity agree very ...