Diesel particulate matter dispersion analysis in underground metal/nonmetal mines using computational fluid dynamics

Diesel Particulate Matter (DPM) is a natural by-product from operating diesel engines. Since diesel power is a major source of energy for mining operations today, the adverse health effects of DPM are of a great concern. To thoroughly resolve DPM problems, it is critical that DPM propagation characteristics be understood to arrive at a sensible and practical method for addressing DPM-related issues. To achieve this, a computational fluid dynamics (CFD) method is used to simulate DPM dispersion and to predict its concentration distribution. Industrial field studies were reconstructed to evaluate the possibility of different CFD models. Experiments were also carried out in the Missouri University of Science and Technology (MISSOURI S&T) Experimental Mine to validate the selected CFD model. Based on the verified CFD model, the DPM dispersion pattern in both a straight entry and a dead-end entry were studied. The effect of variables (for example, different mining operations, inclination of dead-end entry, buoyancy effects, orientation of the tailpipe and a vehicle\u27s motion) on DPM distribution were systematically simulated to reveal high DPM regions in similar real mining scenarios. Different main airflow speeds, diesel particulate filter (DPF), and local ventilation devices were evaluated for effectiveness in clearing the DPM plume. This research can provide a means for identifying high DPM-level areas which can be used in miner health and safety training. It can also improve the understanding of the impacts of various control measures on DPM distribution which can result in an objective decision-making scheme for mining engineers to choose individual or a combination of control strategies to upgrade a miner\u27s working environment --Abstract, page iii

Approaches to safe nanotechnology: managing the health and safety concerns associated with engineered nanomaterials

"Nanotechnology has the potential to dramatically improve the effectiveness of a number of existing consumer and industrial products and could have a substantial impact on the development of new products in all sectors, ranging from disease diagnosis and treatment to environmental remediation. Because of the broad range of possible nanotechnology applications, continued evaluation of the potential health risks associated with exposure to nanomaterials is essential to ensure their safe handling. Engineered nanoparticles are materials purposefully produced with at least one dimension between 1 and 100 nanometers. Nanoparticles often exhibit unique physical and chemical properties that impart specific characteristics essential in making engineered materials, but little is known about what effect these properties may have on human health. Research has shown that the physicochemical characteristics of particles can influence their effects in biological systems. These characteristics include particle size, shape, surface area, charge, chemical properties, solubility, oxidant generation potential, and degree of agglomeration. Until the results from research studies can fully elucidate the characteristics of nanoparticles that may pose a health risk, precautionary measures are warranted. NIOSH has developed this document to provide an overview of what is known about the potential hazards of engineered nanoparticles and measures that can be taken to minimize workplace exposures. " - NIOSHTIC-21. Introduction -- 2. Purpose -- 3. Scope -- 4. Descriptions and definitions -- 5. Potential health concerns -- 6. Potential safety hazards -- 7. Exposure assessment and characterization -- 8. Guidelines for working with engineered nanomaterials -- 9. Occupational health surveillance -- 10. Research needs -- References -- Sources of additional information -- Appendix [Nanoparticle emission assessment technique for identification of sources and releases of engineered nanomaterials]"March 2009.""This report was developed by the scientists and staff of the National Institute for Occupational Safety and Health (NIOSH) who participate in the NIOSH Nanotechnology Research Center (NTRC). Paul Schulte is the manager and Charles Geraci, coordinator of the NIOSH NORA nanotechnology cross-sector program. Special thanks go to Ralph Zumwalde and Laura Hodson for writing and organizing the report and to Mark Methner for the development of the Appendix: Nanoparticle Emission Assessment Technique for Identification of Sources and Releases of Engineered Nanomaterials." - p. xiiiAlso available via the World Wide Web as an Acrobat .pdf file (1.46 MB; 104 p.).Includes bibliographical references (p. 59-70)