Carpentry is another profession learned through apprenticeship. An apprenticeship is a system of training a new generation of practitioners of a trade or profession with on-the-job training and often some accompanying study (classroom work and reading). Apprenticeship also enables practitioners to gain a license to practice in a regulated profession.
A black light is a source of electromagnetic radiation that emits near-ultraviolet light, usually in the 350-375 nanometer wavelength range. This range is just slightly below the 400nm that human eyes can detect. When this light is reflected off certain materials, it looses energy and its wavelength expands to over 400nm. The reflected light is then visible to human eyes, and the illuminated objects appear to glow.
Enwemeka is leading a research effort in Brazil and at UWM that he hopes will ultimately lead to clinical use of NIR and blue light in the U.S. for the treatment of wounds. In the six years since he was asked to test the effects of blue light on MRSA, he says, research on the topic has picked up. But currently, the U.S. Food and Drug Administration (FDA) has not sanctioned the use of blue light in treating wounds, or NIR light for conditions other than wounds and pain.