No abstract

No abstract

Background-Distraction osteogenesis (DO) is a technique of bone lengthening that makes use of the body's natural healing capacity. An osteotomy is created and a rigid distraction device is attached to the bone. After a latency period, the device is activated 2-4 times per day for a total of 1 mm/day of bone lengthening. This technique is used to correct a variety of congenital and acquired deformities of the mandible, midface and long bones. To shorten the treatment period and to eliminate the complications of patient activation of the device, an automated continuous distraction device would be desirable. It has been reported that continuous distraction generates adequate bone with lengthening at a rate of 2 mm/day, thereby reducing the treatment time.

No abstract

A new technology for monitoring airborne heavy metals on aerosols and particulates based on spark-induced breakdown spectroscopy (SIBS) was evaluated at a joint U.S. Environmental Protection Agency (EPA)/U.S. Department of Energy test at the rotary kiln incinerator simulator (RKIS) facility at EPA/Research Triangle Park, NC, in September 1997. The instrument was configured to measure lead and chromium in a simulated combustion flue gas in real time and in situ at target levels of 15 and 75 µg/dry standard cubic meters. Actual metal concentrations were measured during the tests using EPA Reference Method (RM) 29.The SIBS technology detected both lead and chromium at the low-and high-level concentrations. Additionally, the hardware performed without failure for more than 100 hr of operation and acquired data for 100% of the RM tests. The chromium data were well correlated with concentration increases resulting from duct operations and pressure fluctuations that are known to entrain dust. INTRODUCTIONThe U.S. Environmental Protection Agency (EPA) and U.S. Department of Energy (DOE) have recently collaborated to survey available technologies for continuous emissions monitoring (CEM) of hazardous air pollutant metals. The interest of the EPA is to enable implementation of the 1990 Clean Air Act Amendments for compliance monitoring of several toxic metals. DOE has funded some of the new technologies and would be a CEM user for its hazardous waste incinerators and other applications.