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

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)

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

Hyper-personalized Wearable Sensor Fusion for Contextual Interaction

Contextual user interactions with devices and applications today are largely confined to context from location or on-screen context, and to the device at hand. This disclosure describes a context framework that, with user permission, integrates wearable and stationary sensor inputs and traditional digital context into a larger computing ecosystem to deliver content across a range of proactive ambient computing use cases. Devices and apps register their sensors with a context engine and send periodic data updates to the engine. Using machine learning models, the context engine updates the user context based on sensor and external data, and provides the user context to registered devices and apps, which modify their behavior or surface content based on the user’s context

Formulaic Sequences as Fluency Devices in the Oral Production of Native Speakers of Polish

In this paper we attempt to determine the nature and strength of the relationship between the use of formulaic sequences and productive fluency of native speakers of Polish. In particular, we seek to validate the claim that speech characterized by a higher incidence of formulaic sequences is produced more rapidly and with fewer hesitation phenomena. The analysis is based on monologic speeches delivered by 45 speakers of L1 Polish. The data include both the recordings and their transcriptions annotated for a number of objective fluency measures. In the first part of the study the total of formulaic sequences is established for each sample. This is followed by determining a set of temporal measures of the speakers’ output (speech rate, articulation rate, mean length of runs, mean length of pauses, phonation time ratio). The study provides some preliminary evidence of the fluency-enhancing role of formulaic language. Our results show that the use of formulaic sequences is positively and significantly correlated with speech rate, mean length of runs and phonation time ratio. This suggests that a higher concentration of formulaic material in output is associated with faster speed of speech, longer stretches of speech between pauses and an increased amount of time filled with speech

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

Formulaic sequence (FS) cannot be an umbrella term in SLA : Focusing on psycholinguistic FSs and their identification

The term formulaic sequence (FS) is used with a multiplicity of meanings in the SLA literature, some overlapping but others not, and researchers are not always clear in defining precisely what they are investigating, or in limiting the implicational domain of their findings to the type of formulaicity they focus on. The first part of the article provides a conceptual framework focusing on the contrast between linguistic or learner-external definitions, that is, what is formulaic in the language the learner is exposed to, such as idiomatic expressions or collocations, and psycholinguistic or learner-internal definitions, that is, what is formulaic within an individual learner because it presents a processing advantage. The second part focuses on the methodological consequences of adopting a learner-internal approach to the investigation of FSs, and examines the challenges presented by the identification of psycholinguistic formulaicity in advanced L2 learners, proposing a tool kit based on a hierarchical identification method

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

Formulaic Language in Native and Second Language Speakers: Psycholinguistics, Corpus Linguistics, and TESOL

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89473/1/j.1545-7249.2008.tb00137.x.pd