Kirchhoff's law of thermal radiation rarefied material such as air, or transparent material, through which observations can be made. The interface is not a material body and can neither emit nor absorb. It is a mathematical surface belonging jointly to the two media that touch it. It is the site of refraction of radiation that penetrates it and of reflection of radiation that does not. As such it obeys the Helmholtz reciprocity principle. The opaque body is considered to have a material interior that absorbs all and scatters or transmits none of the radiation that reaches it through refraction at the interface. In this sense
Leo Award for Best Sound in a Youth or Children's Program or Series Best Sound Editing in a Youth or Children’s Program or Series Best Sound Editing in a Youth or Children’s Program or Series Best Overall Sound in a Youth or Children’s Program or Series Best Overall Sound in a Youth or Children’s Program or Series Leo Award for Best Sound in a Youth or Children's Program or Series The Leo Award for Best Sound in a Youth or Children's Program or Series is annually presented at the Leo Awards for achievement in sound in a children's television produced in British Columbia. Below are the nominees from each year. Winners in bold.