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Carbon nanotubes (CNTs) are being researched worldwide to create countless new technologies [1,2], including transistors , solar cells, biomaterials, and hybrid advanced composites [3–7]. Concerns exist about the possibility of nanoscale particle release, notably release of CNTs and catalyst particles , during CNT growth and subsequent handling and(More)
BACKGROUND Determination of polyisocyanates is important because they are a major contributor of exposure to the isocyanate functional group in many workplace environments and are capable of inducing sensitization and asthma. However, with multiple different measurement metrics in use, comparison of isocyanate exposure data between studies and development(More)
Airborne nanoparticles released during the synthesis of single-walled and multi-walled carbon nanotubes were measured and characterized. This study reported the field measurements during the development of carbon nanotube production. Monitoring data were taken and the sampling methods to characterize aerosol release were developed along with the(More)
Air purifying dust/mist respirators are presently tested using a silica aerosol under conditions of steady flow. In experiments, the predictive validity of such tests was evaluated by testing respirators using silica and asbestos aerosols under conditions of both steady and cyclic flow. Silica penetration at steady flow was reasonably predictive of silica(More)
Concrete cutting in construction is a major source of exposure to respirable crystalline silica. To reduce exposures, local exhaust ventilation (LEV) may be integrated into the hand tools used in concrete cutting. Volunteers from the New England Laborers Training Center participated in a field study focused on the use of LEV on concrete-cutting hammer(More)
Many hospitals or health care facilities have faced financial difficulties and thus they have attempted to find cost-effective treatment and disposal methods of their regulated medical wastes (RMWs). This study investigated generation volume and sources, composition, and treatment and disposal methods for RMWs obtained from three out of the five typical(More)
This study analyzed the recycling potential of plastic wastes generated by health care facilities. For this study, we obtained waste streams and recycling data from five typical city hospitals and medical centers and three animal hospitals in Massachusetts. We analyzed the sources, disposal costs and plastic content of medical wastes, and also determined(More)
Previously presented theoretical models of the three-dimensional velocity field into a flanged circular hood, both with and without crossdraft, are examined by hot film anemometry. A final model with empirical modifications is selected and validated. Computer generated streamline maps, which enable visualization of the effects of crossdrafts on hood(More)
This study investigated airborne exposures to nanoscale particles and fibers generated during dry and wet abrasive machining of two three-phase advanced composite systems containing carbon nanotubes (CNTs), micron-diameter continuous fibers (carbon or alumina), and thermoset polymer matrices. Exposures were evaluated with a suite of complementary(More)