See your GP if you have: 1  persistent or worrying symptoms that could be caused by haemochromatosis â particularly if you have a northern European family background. 2  a parent or sibling with haemochromatosis, even if you don't have symptoms yourself â tests can be done to check if you're at risk of developing problems.
The reflection of light can be roughly categorized into two types of reflection: specular reflection is defined as light reflected from a smooth surface at a definite angle, and diffuse reflection, which is produced by rough surfaces that tend to reflect light in all directions (as illustrated in Figure 1).
A diffuse nebula also may occur near a cool star. In this case, the ultraviolet light from the star is too weak to make the nebula's gas atoms give off light. But the dust particles in the diffuse nebula reflect the starlight.Astronomers refer to this kind of diffuse nebula as a reflection nebula.If a diffuse nebula occurs in an area that has no nearby stars, it neither emits nor reflects enough light to be visible. In fact, its dust particles blot out the light from the stars behind them. diffuse nebula also may occur near a cool star. In this case, the ultraviolet light from the star is too weak to make the nebula's gas atoms give off light. But the dust particles in the diffuse nebula reflect the starlight.