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A year-long study was conducted in Pinal County, AZ, to characterize coarse (2.5 – 10 μm aerodynamic diameter, AD) and fine (< 2.5 μm AD) particulate matter (PMc and PMf, respectively) to further understand spatial and temporal variations in ambient PM concentrations and composition in rural, arid environments. Measurements of PMc and PMf mass, ions, elements, and carbon concentrations at one-in-six day resolution were obtained at three sites within the region. Results from the summer of 2009 and specifically the local monsoon period are presented. The summer monsoon season (July – September) and associated rain and/or high wind events, has historically had the largest number of PM10NAAQS exceedances within a year. Rain events served to clean the atmosphere, decreasing PMc concentrations resulting in a more uniform spatial gradient among the sites. The monsoon period also is characterized by high wind events, increasing PMc mass concentrations, possibly due to increased local wind-driven soil erosion or transport. Two PM10NAAQS exceedances at the urban monitoring site were explained by high wind events and can likely be excluded from PM10compliance calculations as exceptional events. At the more rural Cowtown site, PM10NAAQS exceedances were more frequent, likely due to the impact from local dust sources. PM mass concentrations at the Cowtown site were typically higher than at the Pinal County Housing and Casa Grande sites. Crustal material was equal to 52-63% of the PMc mass concentration on average. High concentrations of phosphate and organic carbon found at the rural Cowtown were associated with local cattle feeding operations. A relatively high correlation between PMc and PMf (R2 = 0.63) indicated that the lower tail of the coarse particle fraction often impacts the fine particle fraction, increasing the PMf concentrations. Therefore, reductions in PMc sources will likely also reduce PMf concentrations, which also are near the value of the 24-hr PM2.5NAAQS. [ABSTRACT FROM AUTHOR]

The fourth annual Colloquium on Change in Accounting Education, sponsored by the U.S. Institute of Management Accountants, IMA was held during October 12-14, 2000 in the breathtaking high desert, red rock country of Sedona, Arizona. The 2000 Colloquium theme, "How to Enhance Student Learning," was implemented with cutting edge sessions on distance learning, on-line collaborative discovery learning, coaching, e-commerce, the electronic textbook, student competency development, student reflection, and assessment. In addition, several sessions explored how to more creatively present traditional subject matter, and a special Friday evening session provided a first-ever introduction to the Enneagram to accounting educators.