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.
How sound waves work and why nothing can be heard in a vacuum. Sound is created through vibration. This is illustrated with reference to a hand bell, a humming bird and buzzing insects. Sounds cannot be heard in a vacuum, as waves need air to carry them.