The aim of wound bed preparation is to create an optimal wound-healing environment by producing a well vascularised, stable wound bed with minimal exudate. Bacterial load has a direct impact on wound healing. The management of the bacterial load by either local or systemic therapy is important in wound management.
Refraction of Sound Waves. Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves. So if the media (or its properties) are changed, the speed of the wave is changed.
When you are standing against the wind, no matter how loud you shout, your distant friend cannot hear you at all, but you can hear him very well. Does wind scatter sound wave? Surprisingly, this phenomenon is related to refraction! Sound wave travels faster in the air when it is with the wind. Generally speaking, wind speed is lower near the ground because of the presence of blockages, and so it increases with height (Fig. 1). Therefore, when traveling with the wind, sound wave farther from the ground travels faster.