Microscopic Analysis of Aerosol Chemical Mixing State in Cold Environments

Atmospheric aerosol particles impact climate through scattering or absorbing solar radiation, altering surface albedo upon deposition, and aiding in cloud formation. These climate effects depend on the physical and chemical properties of individual particles, including chemical composition, size, phase, and morphology (physicochemical mixing state). In the Arctic, atmospheric particles play a key role in climate processes in the drastically changing region, but Arctic aerosol physicochemical mixing state is not well constrained. Large knowledge gaps remain in understanding the sources and composition of Arctic aerosol, as there is a lack of single particle measurements, particularly across seasons (including fall – winter) and throughout the region (especially the high Arctic). In this dissertation, the physicochemical properties of individual particles were examined at multiple Arctic locations (Bering Strait, Chukchi Sea, coastal Beaufort Sea, and high Arctic Ocean) and during different seasons (winter – spring and summer). The results of this work will increase understanding of Arctic aerosol sources and composition across scales, which is critical to predicting aerosol composition and climate-relevant properties in a New Arctic. Sea spray aerosol (SSA) contributes the largest global flux of particles to the atmosphere, and is therefore an important climate driver, particularly in remote regions, including the Arctic. Laboratory-based sea spray aerosol generation experiments were conducted to evaluate the impacts of seawater temperature, salinity, and marine biology on SSA production and composition in cold environments. These results showed that temperature was as important as biology for controlling SSA production, and organic enrichment was observed in individual SSA particles, indicative of marine organics being transferred to the particle phase. To investigate the role of SSA in the ambient Arctic environment, atmospheric particles were collected during wintertime in the Alaskan Arctic. SSA was a major fraction of the observed aerosol number, demonstrating that sea ice fractures are a source of wintertime aerosol. Further analysis of the wintertime SSA showed a major organic component in the SSA particles, with organic carbon coatings consisting of saccharides, amino acids, and fatty acids. These compounds are derived from exopolymeric substances (EPS) associated with biologically productive sea ice. Greater SSA organic enrichment was observed in winter than in summer, suggesting a unique, previously unidentified source of SSA organics from sea ice algae EPS during winter. Motivated by this work in the wintertime Alaskan Arctic, both ambient and laboratory-generated SSA particles were collected during summer in the high Arctic. SSA production from open leads was observed under high wind conditions, and organic enrichment was observed in both lab-generated and ambient individual SSA particles. Saccharides and fatty acids were identified as the dominant organic compounds present in SSA particles, derived from EPS and marine organics. Atmospheric particle samples were collected in the summertime Alaskan Arctic to investigate the impacts of sea ice loss and increasing development. Samples in the Bering Strait demonstrated great anthropogenic influence. Within the Chukchi Sea, samples were mainly influenced by marine biogenic sources. On the North Slope of Alaska during summer, ammonium sulfate particles demonstrating unique phase and morphology were observed. Organic coatings observed on the particles may play a role in inducing phase changes not previously predicted in the ambient atmosphere. Through these studies, we have gained a greater understanding of the climate-relevant complex atmospheric chemistry and aerosol physicochemical mixing state in the Arctic occurring under changing conditions.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/151719/1/rmkirpes_1.pdfDescription of rmkirpes_1.pdf : Restricted to UM users only

Impact of incentives for greener battery electric vehicle charging - A field experiment

Battery electric vehicles generate a significant share of their greenhouse gas emissions during production and later, when in use, through the energy used for charging. A shift in charging behavior could substantially reduce emissions if aligned with the fluctuating availability of renewable energy. Financial incentives and environmental appeals have been discussed as potential means to achieve this. We report evidence from a randomized controlled trial in which cost-free and “green” charging was advertised via email notifications to customers of a charging service provider. Emails invited to charge during midday hours (11:00 to 15:00) of days with high predicted shares of renewable energy. Results show a significant increase in the number of charging processes in the critical time, and in the amount of energy charged (kWh), despite only marginal monetary savings of 5€ on average. A further increase in kWh charged was observed on weekends. Under the assumption that these charging processes replaced regular overnight charging at home, this represents reduction in CO2 emissions of over 50%

Comparison of Single-Wall Versus Multi-Wall Immersive Environments to Support a Virtual Shopping Experience

With the proliferation of large screen stereo display systems, major consumer product manufacturers are using this technology to test marketing ideas on consumers. One of the performance factors that is of interest to retailers or manufacturers of retail products is the ability of consumers to quickly and easily locate their products within a retail store. Virtual reality technology can be used to create a virtual store that is easily reconfigurable as a test environment for consumer feedback. The research presented in this paper involves a study that compares the use of a multi-wall immersive environment to a single-wall immersive environment. Users were given a list of products to find in the virtual store. A physical mockup of a shopping cart was created and instrumented in order to be used to navigate throughout the virtual store. The findings indicate that participants in the five-wall immersive environment were significantly faster in locating the objects than the participants using the one-wall immersive environment. In addition, participants in the five-wall condition reported that the shopping cart was easier to use than in the one-wall condition. This study indicates that the use of multiple walls to provide an increased sense of immersion improves the ability of consumers to locate items within a virtual shopping experience

Perceptions of Microaggressions and Consequences Differ by Political Orientation

Microaggressions are subtle forms of discriminatory behavior. Women are more likely than men to perceive gender microaggressions (Basford, Offermann, & Behrend, 2014), and political orientation can affect perceptions of microaggressions (Harper, 2018). In this study, we hypothesized that politically liberal women would perceive discriminatory behavior and anticipate negative outcomes for another woman more than politically conservative women, especially when microaggressions were subtler. In a pre-registered experiment, 248 female participants read one of four workplace interaction vignettes depicting microassault, microinsult, microinvalidation, or no microaggression (Basford et al., 2014). Participants rated whether the interaction was discriminatory and if it would result in negative work outcomes for the woman depicted, then completed measures of their personal experiences and characteristics, including four items assessing how liberal/conservative they were (Inbar & Lammers, 2012). As predicted, political orientation and condition affected perceptions of discrimination and predictions of negative work outcomes, though the interaction was not significant. Overall, liberals were more likely than conservatives to perceive microaggressions and to predict negative work outcomes for the woman depicted. However, if the depicted microaggression was subtler, both liberals and conservatives perceived less discrimination and predicted less negative work outcomes. These results suggest that conservative women may discount sexism, rather than liberal women overestimating sexism. Political orientation may decrease perceptions of discrimination against one’s own group for conservatives and liberals in certain situations (cf., Harper, 2018). These findings may aid in understanding political issues such as reactions to Kavanaugh’s hearing

Contributions of transported Prudhoe Bay oil field emissions to the aerosol population in Utqiaġvik, Alaska

Loss of sea ice is opening the Arctic to increasing development involving oil and gas extraction and shipping. Given the significant impacts of absorbing aerosol and secondary aerosol precursors emitted within the rapidly warming Arctic region, it is necessary to characterize local anthropogenic aerosol sources and compare to natural conditions. From August to September 2015 in Utqiaġvik (Barrow), AK, the chemical composition of individual atmospheric particles was measured by computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (0.13-4 μm projected area diameter) and real-time single-particle mass spectrometry (0.2-1.5 μm vacuum aerodynamic diameter). During periods influenced by the Arctic Ocean (70 % of the study), our results show that fresh sea spray aerosol contributed ∼ 20 %, by number, of particles between 0.13 and 0.4 μm, 40-70 % between 0.4 and 1 μm, and 80-100 % between 1 and 4 μm particles. In contrast, for periods influenced by emissions from Prudhoe Bay (10 % of the study), the third largest oil field in North America, there was a strong influence from submicron (0.13-1 μm) combustion-derived particles (20-50 % organic carbon, by number; 5-10 % soot by number). While sea spray aerosol still comprised a large fraction of particles (90 % by number from 1 to 4 μm) detected under Prudhoe Bay influence, these particles were internally mixed with sulfate and nitrate indicative of aging processes during transport. In addition, the overall mode of the particle size number distribution shifted from 76 nm during Arctic Ocean influence to 27 nm during Prudhoe Bay influence, with particle concentrations increasing from 130 to 920 cm-3 due to transported particle emissions from the oil fields. The increased contributions of carbonaceous combustion products and partially aged sea spray aerosol should be considered in future Arctic atmospheric composition and climate simulations

Marine and terrestrial influences on ice nucleating particles during continuous springtime measurements in an Arctic oilfield location

Aerosols that serve as ice nucleating particles (INPs) have the potential to modulate cloud microphysical properties and can therefore impact cloud radiative forcing (CRF) and precipitation formation processes. In remote regions such as the Arctic, aerosol–cloud interactions are severely understudied yet may have significant implications for the surface energy budget and its impact on sea ice and snow surfaces. Further, uncertainties in model representations of heterogeneous ice nucleation are a significant hindrance to simulating Arctic mixed-phase cloud processes. We present results from a campaign called INPOP (Ice Nucleating Particles at Oliktok Point), which took place at a US Department of Energy Atmospheric Radiation Measurement (DOE ARM) facility in the northern Alaskan Arctic. Three time- and size-resolved aerosol impactors were deployed from 1 March to 31 May 2017 for offline ice nucleation and chemical analyses and were co-located with routine measurements of aerosol number and size. The largest particles (i.e., ≥ 3 µm or “coarse mode”) were the most efficient INPs by inducing freezing at the warmest temperatures. During periods with snow- and ice-covered surfaces, coarse mode INP concentrations were very low (maximum of 6 × 10−4 L−1 at −15 ∘C), but higher concentrations of warm-temperature INPs were observed during late May (maximum of 2 × 10−2 L−1 at −15 ∘C). These higher concentrations were attributed to air masses originating from over open Arctic Ocean water and tundra surfaces. To our knowledge, these results represent the first INP characterization measurements in an Arctic oilfield location and demonstrate strong influences from mineral and marine sources despite the relatively high springtime pollution levels. Ultimately, these results can be used to evaluate the anthropogenic and natural influences on aerosol composition and Arctic cloud properties

Marine and terrestrial influences on ice nucleating particles during continuous springtime measurements in an Arctic oilfield location

Aerosols that serve as ice nucleating particles (INPs) have the potential to modulate cloud microphysical properties and can therefore impact cloud radiative forcing (CRF) and precipitation formation processes. In remote regions such as the Arctic, aerosol–cloud interactions are severely understudied yet may have significant implications for the surface energy budget and its impact on sea ice and snow surfaces. Further, uncertainties in model representations of heterogeneous ice nucleation are a significant hindrance to simulating Arctic mixed-phase cloud processes. We present results from a campaign called INPOP (Ice Nucleating Particles at Oliktok Point), which took place at a US Department of Energy Atmospheric Radiation Measurement (DOE ARM) facility in the northern Alaskan Arctic. Three time- and size-resolved aerosol impactors were deployed from 1 March to 31 May 2017 for offline ice nucleation and chemical analyses and were co-located with routine measurements of aerosol number and size. The largest particles (i.e., ≥&thinsp;3&thinsp;µm or “coarse mode”) were the most efficient INPs by inducing freezing at the warmest temperatures. During periods with snow- and ice-covered surfaces, coarse mode INP concentrations were very low (maximum of 6&thinsp;×&thinsp;10−4&thinsp;L−1 at −15&thinsp;∘C), but higher concentrations of warm-temperature INPs were observed during late May (maximum of 2&thinsp;×&thinsp;10−2&thinsp;L−1 at −15&thinsp;∘C). These higher concentrations were attributed to air masses originating from over open Arctic Ocean water and tundra surfaces. To our knowledge, these results represent the first INP characterization measurements in an Arctic oilfield location and demonstrate strong influences from mineral and marine sources despite the relatively high springtime pollution levels. Ultimately, these results can be used to evaluate the anthropogenic and natural influences on aerosol composition and Arctic cloud properties.</p

From Harlot to Human Being: The Revised Anna Karenina

Leo Tolstoy�s novel Anna Karenina has been traditionally viewed as a moral treatise on adultery. However, this shallow approach misses Tolstoy�s criticism of the hypocritical customs of Russian high society and does not explain his many radical revisions of the novel. While researching Tolstoy�s views on women and how they impacted his treatments of the character of Anna, I discovered little explanation for what prompted these revisions. Due to the personal and almost autobiographical nature of Tolstoy�s writing, I therefore also investigated the events which occurred in his life during the writing of this novel to learn how his religious and philosophical conversion may have changed his views�and the novel. I found that an understanding of Tolstoy and his changing views is crucial to gaining a true understanding of Anna Karenina. Tolstoy lived in a patriarchal culture and this traditional structure must be examined in order to establish a context for the novel. His traditional views are illustrated in the novel, although his conversion illustrates how his views change over time and, in turn, influence his writing of the novel. I closely analyzed Anna Karenina and paralleled excerpts from both the first drafts and the finished work with Tolstoy�s life in the 1870�s. Translated diaries, letters, and biographies added to my understanding of Tolstoy and the novel. I chose to focus greatly on Tolstoy�s life thanks to the influence of his life on the novel. Through this research I found that Tolstoy�s philosophical and religious conversion led to more tolerance and compassion in his life, which is reflected within the revisions of the novel. These revisions illustrate how Tolstoy does not condemn Anna, but instead condemns the customs of the high society for their hypocrisy in condemning her and the superficiality of their lives. Through his religious conversion, he began to believe that the life of hard agricultural work in the country was closer to the ideals of biblical proverbs, and therefore more holy. The frivolous city life, however, he viewed as corrupting. This corruption is what Tolstoy condemns in the novel. Through the character of Anna, he illustrates how one must remain true to one�s own conscience and not the conscience of a false society. Tolstoy�s conversion thus led to the revisions in which he shifted blame from Anna to the society around her. These results add to the scholarship already in the field, with the added perspective of the influence of Tolstoy�s conversion on his writing of Anna Karenina. After this novel, he wrote works only on moral and religious themes. The impact of Tolstoy�s conversion on his life and on his later works is widely documented, but the impact of it on his revisions of Anna Karenina is less studied. Like the person Tolstoy, himself, his writing is complicated with many layers. Future research will likely reveal even deeper layers within this text, further adding to the understanding of the novel

Value of the 3D Product Model Use in Assembly Processes: Process Planning, Design, and Shop Floor Execution

Organizations can enhance the value of their assembly planning, assembly design, and assembly shop floor execution through the use of the 3D product model. Once a tool targeted at product design, the 3D product model, enabled by current and emerging manufacturing process management technologies, can create additional value for organizations when used in assembly processes. The research survey conducted and described in this paper demonstrates the value organizations have seen in using the 3D product model in the assembly process. The paper also explores the current state of those organizations who have not yet implemented the use of the 3D product model in their assembly processes and the value that they foresee for possible future implementation. The essential findings of this research are the five qualitative areas in which value is derived from using the 3D product model in complex assembly processes and how those value drivers apply across various industries and organization sizes. These results provide a framework for future research to develop quantitative models of the value of the 3D product model use in assembly processes