Weight on bit downhole MWD sensors can measure weight-on-bit more accurately and transmit the data to the surface. Weight on bit Weight on bit (WOB), as expressed in the oil industry, is the amount of downward force exerted on the drill bit and is normally measured in thousands of pounds. Weight on bit is provided by drill collars, which are thick-walled tubular pieces machined from solid bars of steel, usually plain carbon steel but sometimes of nonmagnetic nickel-copper alloy or other nonmagnetic premium alloys. Gravity acts on the large mass of the collars to provide the downward force needed for the bits to
Isotopes of livermorium Isotopes of livermorium Livermorium (Lv) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was Lv in 2000. There are four known radioisotopes from Lv to Lv, as well as a few suggestive indications of a possible heavier isotope Lv. The longest-lived of the four well-characterised isotopes is Lv with a half-life of 53 ms. The below table contains various combinations of targets and projectiles which could be used to form compound nuclei with atomic number 116. In 1998, the team