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.
The fluorescent tube converts electrical energy into light. much more efficiently at high frequencies than at line. frequencies of 50 or 60Hz. Typical ballast frequencies are in. the range 40kHz to 150 kHz. When regulating the current the excess voltage is. dropped across the leakage inductance of the ballast with. minimal Watts loss as compared to the copper losses of. conventional ballast. Electronic ballasts are commonplace, reliable and efficient.