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).
1. Reflection of sound waves. If a source of sound is directed at a vertical surface some distance away, an ECHO may be heard. Sound waves bounce off the vertical surface, and are REFLECTED back towards the source. Reflection of sound waves obey the laws of reflection. The human ear cannot distinguish between two sound bursts if they are less than about 0.1 s apart. For that reason, in order to hear an echo, the reflecting object must be more than 17 m away from the hearer (assuming sound travels at 340 mÂ·s-1).