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.
Ballast 20mm. Building Ballast is a mix of sand and 20mm stone. Suitable for using with fence posts and making concrete for paths, bases for under garden buildings, concrete floor in extensions or even foundations for a building.20mm Crusher Run.hether you are looking for building sand, ballast or crusher run we have it. Our products are available in a range of sizes however most are supplied in either bulk bags or 25kgs pre-pack. All of our building aggregates are of the finest quality and are exceptionally hardwearing.