During August and September 2012, a study was conducted to determine the sources of PM2.5 adjacent to the I-710 Long Beach Freeway. The site is directly affected by the emissions from heavy diesel traffic flowing from major container ports about 10 km south of the sampling site. Hourly average data were obtained for particulate species including PM2.5, black carbon and UV absorbing carbon, EC, fine particulate nonvolatile and semi-volatile organic material (NVOM and SVOM), sulfate, nitrate, chloride, ammonium ion, and Na ion, and for related factors including O3, CO, NOX, SO2, and total traffic flow on the I-710. A total of 520 hourly averaged data sets with 15 measured variables were analyzed by EPA-PMF v5.0. The data were best described by a 10-factor solution. Based on the composition and diurnal patterns of the factors, they were assigned to three diesel-related factors (two of which appeared to represent traffic from the ports and one general freeway diesel factor), a light-duty, spark-ignition vehicle-related factor, three secondary factors (one of which was associated with O3 formation processes), and three factors dominated by sulfate, SO2, and chloride, respectively. The diurnal patterns for these last three factors are strongly correlated. Meteorological and refinery upset data indicate that they are associated with emissions from a nearby refinery. The results of the PMF analysis were combined with nephelometer light scattering, corrected for coarse particle scattering and estimated aerosol water content in a multilinear regression analysis to identify visibility degradation sources. Major contributors were the aerosol water content, and the secondary PMF factors associated with either Nitrate and NVOM or NVOM and SVOM. The use of hourly average data made possible the identification of factors associated with gasoline vehicle emissions and both port and non-port diesel emissions.Implications: Hourly averaged data were obtained for PM2.5, its components and factors related to primary emissions and the formation of secondary material at a near freeway sampling location adjacent to the I-710 freeway just south of the Long Beach Boulevard entrance and 10 km north of the Ports of Long Beach and Los Angeles. The major objective of the study was to determine the impact of traffic from the ports at the monitoring site. This manuscript reports on the PMF analysis of the data set. Factors related to both diesel traffic originating from the ports and diesel traffic from non-port origins were identified. The diesel traffic originating from the ports was responsible for 9% of the total traffic and 95% of the BC measured at the sampling site. The non-port diesel traffic was responsible for 15% of the total traffic and 5% of the BC. While the Port 1 diesel traffic coming from the ports contributed a large fraction of the BC, this source contributed only 2% of the CO and 5% of the NOX at the sampling site. The impact of these traffic sources on light scattering was also small. Analysis of sources of sulfate and SO2 at the sampling site indicated that these species did not come from port activities of ships at or approaching the port, but rather from upset flare events at a nearby oil refinery.

As the computer industry retools to leverage massively parallel graphics processing units (GPUs), this book is designed to meet the needs of working software developers who need to understand GPU programming with CUDA and increase efficiency in their projects. CUDA Application Design and Development starts with an introduction to parallel computing concepts for readers with no previous parallel experience, and focuses on issues of immediate importance to working software developers: achieving high performance, maintaining competitiveness, analyzing CUDA benefits versus costs, and determining application lifespan. The book then details the thought behind CUDA and teaches how to create, analyze, and debug CUDA applications. Throughout, the focus is on software engineering issues: how to use CUDA in the context of existing application code, with existing compilers, languages, software tools, and industry-standard API libraries. Using an approach refined in a series of well-received articles at Dr Dobb's Journal, author Rob Farber takes the reader step-by-step from fundamentals to implementation, moving from language theory to practical coding.Includes multiple examples building from simple to more complex applications in four key areas: machine learning, visualization, vision recognition, and mobile computingAddresses the foundational issues for CUDA development: multi-threaded programming and the different memory hierarchyIncludes teaching chapters designed to give a full understanding of CUDA tools, techniques and structure.Presents CUDA techniques in the context of the hardware they are implemented on as well as other styles of programming that will help readers bridge into the new materialTable of Contents1. First Programs and How to Think in CUDA 2. CUDA for Machine Learning and Optimization 3. The CUDA Tool Suite: Profiling a PCA/NLPCA Functor 4. The CUDA Execution Model 5. CUDA Memory 6. Efficiently Using GPU Memory 7. Techniques to Increase Parallelism 8. CUDA for All GPU and CPU Applications 9. Mixing CUDA and Rendering 10. CUDA in a Cloud and Cluster Environments 11. CUDA for Real Problems: Monte Carlo, Modeling, and More 12. Application Focus on Live Streaming Video

Grand Canyon National Park (GCNP) is a mandatory Class I federal area that is afforded visibility protection under the Federal Clean Air Act. In this paper, we have examined the effects on visibility and particulate sulfur (Sp) at GCNP as a result of reducing sulfur dioxide (SO2) emissions by 90% from the Navajo Generating Station (NGS). Scrubbers were retrofitted to each of the three units at NGS during 1997, 1998, and 1999. The Inter-agency Monitoring of Protected Visual Environments aerosol network database affords us an opportunity to examine trends in Sp and extinction both prescrubber and postscrubber. The NGS impacts GCNP primarily during the winter (December to February). During winter, at times, there are fogs, stratus, and high-relative humidity in the Grand Canyon. When the NGS plume interacts with these fogs and stratus, rapid conversion of SO2 to Sp can occur. A variety of analytical techniques were used, including cumulative frequency plots of Sp and extinction, and chemical mass balance and tracer source apportionment analysis. We also deployed P value statistical analysis of "extreme" Sp values. Before scrubbers were installed, values of Sp approaching 2 microg/m3 were occasionally observed. Because scrubbers have been installed, high levels of Sp have been markedly reduced. Statistical P value analysis suggests that these reductions were significant. Furthermore, we have also observed that Sp has been reduced throughout the cumulative frequency curve during winter by approximately 33% since scrubbers were installed. By contrast, during summer when the NGS impact on the Canyon is minimal, there has been only a relatively small decrease in Sp.

Project MOHAVE was a major air quality and visibility research program conducted from 1990 to 1999 to investigate the causes of visibility impairment in the Grand Canyon National Park region. At Meadview, a remote monitoring site just west of the Grand Canyon National Park, on September 1 and 2, 1992, the concentrations of sulfate (3.1 and 4.3 μg sulfate/m3) were the highest seen in 6 years of monitoring at this site. During this period, the concentrations of SO2 at Meadview were also abnormally high and approximately three times the sulfate concentrations, on a nmol/m3 basis. High concentrations of sulfate and SO2 extended south into southern Arizona and northwestern Mexico. Based on ambient atmospheric conditions, emissions from the Mohave Power Project (MPP) 110 km upwind of Meadview could not have been responsible for the majority of the regionally observed sulfur oxides. The geographical distribution of SO2 and sulfate, and available source information suggest that northwestern Mexico was a significant source of the unusually high observed sulfur oxides. A CMB model developed during Project MOHAVE was used to apportion sulfur oxides at Meadview and other sampling sites throughout the study region for August 31–September 2, 1992. The results indicate that the contribution of MPP to sulfate at Meadview was typical. However, the transport of SOx from northwestern Mexico was elevated throughout much of the region during this time period. This led to the large increase in sulfate concentrations at Meadview on September 1 and 2. These results indicate that emissions from Mexico can be a significant source of particulate material in the Grand Canyon.

Windblown fugitive dust contributes to violations of air quality standards for particulate matter <10 mu m aerodynamic diameter (PM10). In the western Mojave Desert of California, approximately 1070 ha of previously tilled or over-grazed land impacted downwind metropolitan areas by wind-driven emissions of dust. A protocol of furrowing across the wind and direct seeding of three native perennial shrubs and a bunch grass helped reduce fugitive dust emissions in this area by more than 95%. Seeded species varied from 35 to 97% of Living plant cover in individual years, reflecting rainfall patterns. In areas of deep sand, Indian ricegrass (Achnatherum hymenoides Roemer & Shultes) outperformed the shrubs, while fourwing saltbush [Atriplex canescens (Pursh) Nutt.] exhibited the most widespread establishment. This revegetation was achieved in an anomalous year with above average and late rainfall that eliminated early competition from annual species and later fostered abundant shrub growth. This success was not reproducible in more normal years, when minimal disturbance protocols such as broadcasting of seed on the untilled soil surface were as effective and less costly. We conclude: (i) direct seeding can lead to plant establishment in favorable years, but is likely to fail in any given year, (ii) direct seeding should be implemented with little soil disturbance, (iii) the native fourwing saltbush is the most likely species to become established in this environment, and (iv) unpredictable rainfall and temperature require that direct seeding be backed up with alternative strategies to achieve reliable dust and PM10 mitigation in arid environments.