Boart Longyear diamond drilling firm; Brainard-Kilman, a maker of civil engineering devices, such as well monitoring and test equipment; and ChemGrout a mfg of cement grouting equipment. Longyear acquired Slope Indicator Company, the nation's largest producer of geotechnical instruments, and Northern Air Supply in 1988, followed by the Campbell Pacific Division in 1989 and WTD Environmental Drilling in 1990. Then in 1994, North Star Drilling Company, specializing in sonic drilling was acquired. On January 2, 1995, Boart International and the Longyear Company officially merged into a single company and changed its name to Boart Longyear Limited. At this point the two companies
Radioactive waste or at least closure, of several sites. Radioactive medical waste tends to contain beta particle and gamma ray emitters. It can be divided into two main classes. In diagnostic nuclear medicine a number of short-lived gamma emitters such as technetium-99m are used. Many of these can be disposed of by leaving it to decay for a short time before disposal as normal waste. Other isotopes used in medicine, with half-lives in parentheses, include: Industrial source waste can contain alpha, beta, neutron or gamma emitters. Gamma emitters are used in radiography while neutron emitting sources are used in a range of