A composite member includes a matrix part including an inorganic substance, and an organic infrared absorbing material present in a dispersed state inside the matrix part. The composite member has a porosity of 20% or less in a section of the matrix part. A heat generation device includes the composite member, and an infrared light source for irradiating the composite member with infrared rays. A building member and a light emitting device each include the composite member, or the heat generation device.

The present invention relates to floor levelling compositions which can be mixed with water and comprise fluorescein or a derivative thereof. The present invention further relates to the use of fluorescein or fluorescein derivatives as indicator for the readiness for being covered of a floor levelling composition mixed with water.

The present invention relates to floor levelling compositions which can be mixed with water and comprise fluorescein or a derivative thereof. The present invention further relates to the use of fluorescein or fluorescein derivatives as indicator for the readiness for being covered of a floor levelling composition mixed with water.