As described previously, cervical cancers are caused by infection with one of the high-risk HPV types. However, since not all people who are infected with HPV will develop cancer, it is likely that other factors also play a role in the development of cervical cancer.
ballast factor (BF) - The ratio of the light output of a fluorescent lamp or lamps operated on a ballast to the light output of the lamp(s) operated on a standard (reference) ballast. Ballast factor depends on both the ballast and the lamp type; a single ballast can have several ballast factors depending on lamp type. compact fluorescent lamp (CFL) - A family of single-ended fluorescent-discharge light sources with small-diameter [16-millimeter (5/8-inch) or less] tubes.
Pacific Energy Center Factsheet: Energy Efficient Fluorescent Ballasts Page 5 of 5. http://www.pge.com/pec. Input Watts is the power required to operate the lamp/ballast combination measured in watts. Lamp Efficacy is the ratio of the rated light output of a lamp to its rated power consumption.