Temporal and spatial trends of fine particulate matter composition in Fairbanks, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2016Fairbanks, AK experiences extreme winter pollution episodes that result in violations of the Fine Particulate (PM₂.₅) National Ambient Air Quality Standards and pose significant health risks for inhabitants. We analyzed the 2006-2014 wintertime (November 1 to the end of February) PM₂.₅ composition from four sampling sites in the Fairbanks North Star Borough (FNSB) to provide insight into sources and trends. We developed conversions for particulate carbon measurements that were sampled/analyzed with different methods to allow quantitative comparisons. Using these conversions, we found excellent mass closure between PM₂.₅ mass concentration reconstructed from particulate composition and directly measured PM₂.₅ mass concentration. The North Pole Fire Station #3 site (NPFS3) PM₂.₅ mass concentration is nearly double the concentration at other sites in the FNSB and significantly different (t-test on log normalized data, 95% conf.). We observe significant differences (t-test, 95% conf.) in the PM₂.₅ composition between the NPFS3 site and all other sites for most components. Comparison to source profiles indicates that the difference in SO₄²⁻/PM₂.₅ and organic carbon (OC)/PM₂.₅ ratios is attributable to greater use of wood heat in the areas surrounding the NPFS3 site than in Fairbanks. This interpretation is supported by the results of the Home Heating Survey, which found a greater reported use of wood for heat in North Pole than in Fairbanks. Interannual variability is observed in the PM₂.₅ composition. The increase in fuel oil price in 2009 is correlated with an increase in OC/PM₂.₅ ratio and a decrease in the SO₄²⁻/PM₂.₅. The interannual variability of the SO₄²⁻/PM₂.₅ and NH₄⁺/PM₂.₅ ratios are correlated. The particles appear to be neutralized until 2010 when a drop in NH₄⁺ is not accompanied by as large of a drop in anions leaving the particles acidic. The mean sulfur oxidation ratio is 5%, attributable to primary and possible secondary oxidation of SO₂. The results of our analysis supports modeling results that wood smoke contributes a large fraction to the Fairbanks area PM₂.₅. Our work also identified changes in the concentration, composition and spatial distribution of PM₂.₅ that may help air quality managers in identifying effective PM₂.₅ control strategies.Chapter 1: Introduction -- 1.1 Motivation -- 1.2 Review of Health Effects of Fine Particulates -- 1.3 Background -- 1.3.1 Fairbanks Emission Sources -- 1.3.2 Current Mitigation -- 1.4 Particle Formation -- 1.4.1 Primary Particles -- 1.4.2 Secondary Particle Formation -- 1.4.3 Sulfur Oxidation -- 1.5 Transport -- 1.6 Source Profiles -- 1.7 Prior Modeling Results -- 1.7.1 SANDWICH Mass Balance Modeling -- 1.7.2 Organic Carbon Mass Estimations -- 1.7.3 Source Apportionment Modeling -- 1.8 Hypotheses -- 1.8.1 Hypothesis 1: Significant differences in PM₂.₅ composition and mass concentration will exist between Norh Pole and Fairbanks sampling sites -- 1.8.2 Hypothesis 2: A reduction in the OC/PM2.5 ratio will be observed after 2010 -- 1.8.3 Hypothesis 3: Secondary sulfur oxidation is taking place during Fairbanks Winter -- Chapter 2: Methods, Sampling Sites and Data Sources -- 2.1 Sampling and Analysis Methods -- 2.1.1 Sampling Methods -- 2.1.1.1 Sampling Methods Overview -- 2.1.1.2 Carbon Sampling Method Discrepancies -- 2.1.2 Analysis Methods -- 2.1.2.1 Inorganic Analysis -- 2.1.2.2 Carbon Analysis -- 2.1.2.3 Carbon Analysis Method Discrepancies -- 2.2 Associated Error -- 2.2.1 Sampling Error -- 2.2.2 Analytical Error -- 2.3 Data Acquisition and Processing Overview -- 2.4 Initial Data Processing -- 2.4.1 Data Processing- Blank Correction -- 2.4.2 Calculation of the Reconstructed Mass Concentration -- 2.4.3 Data Processing: OC/EC Correction Methods -- 2.4.3.1 Motivation -- 2.4.3.2 Fresno OC/EC Correction -- 2.4.3.3 Fairbanks OC/EC Correction -- 2.4.3.4 OC/EC Correction Checks -- 2.5 Data Processing– Sample Variability -- 2.6 Data Processing- Quality Control (QC) -- 2.7 Data Processing- Statistical Methods -- 2.8 Data Processing– Sulfur Oxidation -- 2.8.1 Sulfur Oxidation Ratio (SOR) Calculation -- 2.8.2 Determination of Secondary Oxidation -- 2.8.3 Metal Catalyst Investigation -- 2.9 Data Processing - Non-Sulfate Sulfur (NSS) -- 2.10 Data Processing– Spatial Analysis -- 2.11 Data Processing – Temporal Analysis -- 2.12 Source Profile Selection Methods -- 2.13 Source Profile Processing Methods -- Chapter 3: Results of PM2.5 Analysis -- 3.1 OC/EC Correction -- 3.1.1 Method Performance -- 3.1.2 Comparison to Fresno Based Method -- 3.2 Temporal Trends -- 3.2.1 Meteorological Impacts on PM₂.₅ -- 3.2.2 Component Mass Concentrations in Air -- 3.2.3 Interannual and Daily Variability in Component/PM₂.₅ Ratios -- 3.2.4 Trends in Component/PM₂.₅ Ratios -- 3.2.5 Correlation of Component/PM₂.₅ Ratios with Temperature -- 3.3 Spatial Trends -- 3.3.1 Gravimetric PM₂.₅ -- 3.3.2 Component/PM₂.₅ Ratio Trends -- 3.4 Sulfur Oxidation -- 3.4.1 Sulfur Oxidation Ratio (SOR) -- 3.4.2 Non-Sulfate Sulfur -- 3.5 Source Profile Averages -- Chapter 4: Discussion -- 4.1 OC/EC Correction -- 4.2 Temporal Trends -- 4.2.1 Meteorological Impacts on PM₂.₅ -- 4.2.2 Component Mass Concentrations -- 4.2.3 Interannual and Daily Variability in Component/PM₂.₅ Ratios -- 4.2.4 Trends in Component/PM₂.₅ Ratios -- 4.3 Spatial Trends -- 4.3.1 Gravimetric PM₂.₅ -- 4.3.2 Composition Differences -- 4.4 Sulfur Oxidation -- 4.5 Non-Sulfate Sulfur (NSS) -- 4.6 Applications and Limitations of Source Profiles -- Chapter 5: Conclusions and Future Work -- 5.1 Conclusions with Regard to the Three Hypotheses -- 5.1.1 Hypothesis 1: Significant differences in PM2.5 composition and mass concentration will exist between North Pole and Fairbanks sampling sites -- 5.1.2 Hypothesis 2: A reduction in the OC/PM2.5 ratio will be observed after 2010 -- 5.1.3 Hypothesis 3: Secondary sulfur oxidation is taking place during the Fairbanks winter -- 5.3 Future Work: Investigating Recent Changes in Emissions -- 5.4 Future Work: Improved Statistics and Trend Analyses -- 5.5 Future Work: Improved Source Apportionment -- 5.6 Accessing Data for Future Research -- Literature Cited

Change detection for optimized semantic video analysis

Semantic analysis or annotation of videos is most useful when done frequently enough to capture the significant moments of a video, but not so frequently that annotations become busy and repetitive. With current techniques, semantic analysis is done too often, overloading the semantic analyzer and overwhelming the viewer with frequent, repetitive, or similar annotations of insubstantially differing frames. This disclosure presents techniques that detect substantial changes in the video for the purposes of semantic analysis. Timely and relevant annotations are presented to viewers without overwhelming them and without overloading the semantic analyzer

Controlling the density of user-generated content in augmented reality

In a multi-user augmented reality (AR) environment, a user can insert virtual objects that other users can see. If users place objects without constraint, then the AR view can become dense, overwhelming, and hard to understand. Per the techniques of this disclosure, the density of objects in an AR environment is constrained by maintaining a minimum distance between existing and newly-placed objects

Synesthetic Soundtrack

This disclosure describes techniques to generate an audio experience or soundscape corresponding to the visual field of a user. With user permission, objects within the feed of a head-mounted camera are semantically identified using computer vision techniques. Based on the detected objects, a unique audio experience, shaped by the world around a user and by the physical items they engage with, is generated

Determinants of Breast Conservation Rates: Reasons for Mastectomy at a Comprehensive Cancer Center

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75345/1/j.1524-4741.2008.00668.x.pd

Physicality and language learning

The study draws on the digital technology which allows users to be able to learn both linguistic and non-linguistic skills at the same time. Activity recognition as well as wireless sensor technology, similar to a Nintendo Wii, is embedded or attached to the equipment and ingredients, allowing users to detect and evaluate progress as they carry out their cooking tasks in a real world kitchen. 48 adult participants from 20 countries in total cook, both in a digital kitchen by using real objects and in the classroom by looking at typical pictures/photos in the textbook. These learners from diverse cultural background pose a great potential to the generalizability of the current study. Research questions are: does using real objects to cook in the digital kitchen help students learn vocabulary items better than looking at photos of the objects in the classroom? If so, to what extent? This study attempts to see the effect of physicality in combination with digital technology on foreign vocabulary learning by a experimental design. This project not only helps address well-known problems in relation to classroom teaching and learning, but supports the development of innovative information and communications technology for language learning across the world

How much collocation knowledge do L2 learners have?: the effects of frequency and amount of exposure

Many scholars believe that collocations are difficult to learn and use by L2 learners. However, some research suggests that learners often know more collocations than commonly thought. This study tested 108 Spanish learners of English to measure their productive knowledge of 50 collocations, which varied according to corpus frequency, t-score, and MI score. The participants produced a mean score of 56.6% correct, suggesting that our learners knew a substantial number of collocations. Knowledge of the collocations correlated moderately with corpus frequency (.45), but also with everyday engagement with English outside the classroom, in activities like reading, watching movies/TV, and social networking (composite correlation = .56). Everyday engagement also had a stronger relationship with collocation knowledge than years of English study (.45)

Why do Asian-American women have lower rates of breast conserving surgery: results of a survey regarding physician perceptions

<p>Abstract</p> <p>Background</p> <p>US Asian women with early-stage breast cancer are more likely to receive a modified radical mastectomy (MRM) than White women, contrary to clinical recommendations regarding breast conserving treatment (BCT).</p> <p>Methods</p> <p>We surveyed physicians regarding treatment decision-making for early-stage breast cancer, particularly as it applies to Asian patients. Physicians were identified through the population-based Greater Bay Area Cancer Registry. Eighty (of 147) physicians completed a questionnaire on sociodemographics, professional training, clinical practices, and perspectives on the treatment decision-making processes.</p> <p>Results</p> <p>The most important factors identified by physicians in the BCT/MRM decision were clinical in nature, including presence of multifocal disease (86% identified this as being an important factor for selecting MRM), tumor size (71% for MRM, 78% for BCT), cosmetic result (74% for BCT), and breast size (50% for MRM, 55% for BCT). The most important reasons cited for the Asian treatment patterns were patient attitudes toward not needing to preserve the breast (53%), smaller breast sizes (25%), and fear and cultural beliefs (12%).</p> <p>Conclusion</p> <p>These survey results suggest that physicians perceive major roles of both clinical and cultural factors in the BCT/MRM decision, but cultural factors may be more relevant in explaining surgical treatment patterns among Asians.</p