This thesis consists of three chapters. The first chapter is sole-authored and is titled `Cross-border merger waves.' The second chapter is coauthored work with Professor David Mauer and Kyeong Hun Lee and is titled `Human capital relatedness and corporate mergers and acquisitions.' The third chapter is coauthored work with Professor Amrita Nain and Kyeong Hun Lee and is titled `Repetitive cross-border mergers and acquisitions.' First chapter examines the valuation effects of cross-border merger and acquisition (M&A) waves that occurred during 1990 and 2010. I document that, like domestic mergers, cross-border mergers cluster by industry and time. Cross-border M&A waves create value overall: acquirer announcement returns as well as combined acquirer and target announcement returns within waves are positive and significantly higher than those outside of waves. Post-merger operating performance is also better for within-wave cross-border deals. In stark contrast to domestic merger waves, deals undertaken later in cross-border merger waves tend to outperform those earlier in waves within a given industry. The late entrant's outperformance is stronger if the target country is different from the acquirer country in terms of culture, financial development, and legal system. Firms' acquisition decisions in cross-border merger waves depend on the stock market reaction to recent deals undertaken by industry peers in the same country. Overall, my results suggest that cross-border acquisitions promote efficient redeployment of corporate assets. Further, information asymmetry stemming from differences between acquirer and target countries plays an important role in the timing and performance of reallocation of corporate assets across national borders. Second chapter studies the effects of human capital relatedness on the likelihood of a merger pairing and on the valuation consequences of deals. Using comprehensive and unique occupation data, we propose a novel measure to quantify the relatedness of firms' human capital. We find that a firm is more likely to acquire a target with related human capital. Mergers between firms closely related in terms of human capital achieve greater synergies. The results are robust to other pairwise relatedness measures that may affect merger likelihood and synergy, such as product market synergies. Overall, the evidence suggests that human capital relatedness is an important factor in mergers and acquisitions. Third chapter examines repetitive deals in the same target country. We find that as acquirers repeat cross-border deals in the same country, (i) the time between successive deals declines, (ii) the percentage of ownership stake acquired increases, and (iii) the percentage of consideration paid in cash increases. To further distinguish whether such patterns are consistent with learning or hubris, we examine repetitive cross-border deals at two different stages of learning: experience-building versus memory-loss periods (as in Hayward (2002)). We find that as the acquirer makes more deals in the country, the time between deals decreases and the abnormal announcement return increases in experience-building periods, whereas such patterns do not exist or are reversed in memory-loss periods. Our results suggest that firms gain by learning as they repeat acquisitions in the same country.

The similarity between objects is judged in a wide variety of contexts from visual search to categorization to face recognition. There is a correspondingly rich history of similarity research, including empirical work and theoretical models. However, the field lacks an account of the real time neural processing dynamics of different similarity judgment behaviors. Some accounts focus on the lower-level processes that support similarity judgments, but they do not capture a wide range of canonical behaviors, and they do not account for the moment-to-moment stability and interaction of realistic neural object representations. The goal of this dissertation is to address this need and present a broadly applicable and neurally implemented model of object similarity judgments. I accomplished this by adapting and expanding an existing neural process model of change detection to capture a set of canonical, task-general similarity judgment behaviors. Target behaviors to model were chosen by reviewing the similarity judgment literature and identifying prominent and consistent behavioral effects. I tested each behavior for task-generality across three experiments using three diverse similarity judgment tasks. The following behaviors observed across all three tasks served as modeling targets: the effect of feature value comparisons, attentional modulation of feature dimensions, sensitivity to patterns of objects encountered over time, violations of minimality and triangle equality, and a sensitivity to circular feature dimensions like color hue. The model captured each effect. The neural processes implied by capturing these behaviors are discussed, along with the broader theoretical implications of the model and possibilities for its future expansion.

Swine workers in concentrated animal feeding operations (CAFOs) are at risk of developing respiratory illnesses as a result of exposure to a combination of ammonia (NH3), carbon dioxide (CO2), and dust. The purpose of this study was to determine whether the use of a recirculating ventilation system with a filter-type air pollution control (APC) unit (Shaker Dust Collector, United Air Specialists Inc.), selected to control dust, would inadvertently increase NH3 and CO2 concentrations in a farrowing room. During the 2013-14 winter season, NH3 and CO2 concentrations were measured at six fixed locations throughout the farrowing room test site. Direct reading instruments (NH3: VRAE, Rae Systems Inc.; CO2: ToxiRAE Pro, Rae Systems Inc.) were deployed for 24-hour periods throughout the season on 18 randomly selected days. Contaminant concentrations were measured and compared by ventilation status (APC ON: 11 days, APC OFF: 7 days). Ammonia concentrations were above the literature recommended limit (7 ppm) on 13 of the 18 sample days (72%) and even exceeded the threshold limit value (TLV) of 25 ppm on one of the sample days. Carbon dioxide concentrations exceeded the literature recommended limit of 1540 ppm on all 18 sample days, and average concentrations were half of the TLV (2500 ppm). There was no statistically significant difference in NH3 (p > 0.23) or CO2 (p > 0.67) when concentrations were compared by APC status. The results of this study indicate a recirculating ventilation system with filter dust control does not increase NH3 or CO2 concentrations spatially or temporally in the room during operation. Future work will investigate engineering control options to reduce CO2 concentrations in the farrowing room.

The research presented in this doctoral dissertation strived to increase knowledge with respect to respirators performance in the workplace by evaluating particle penetration and breathing resistance (BR) of N95 filtering face-piece respirators (FFRs) under simulated air environmental conditions, determining maximum particle penetration of uncertified dust masks (UDMs) against sodium chloride (NaCl) and BR of UDMs and FFRs when challenged against Arizona road dust (ARD), and evaluating BR of FFRs while performing power washing in swine rooms. A novel test system was used to measure particle penetration and BR of two N95 FFRs under modified environmental conditions. NaCl particle penetration through the FFR was measured before and after the BR test using a scanning mobility particle sizer. BR of the FFR was measured by mimicking inhalation and exhalation breathing, while relative humidity and temperature were modified. BR was evaluated for 120 min under cyclic flow and four temperature and relative humidity air conditions. The BR of the FFRs was found to increase significantly with increasing relative humidity and lowering temperature upstream the FFR (p < 0.001). Measured particle penetration was not influenced by the simulated air environmental conditions. Differences in BR was observed between FFRs indicating that FFRs filtering media may perform differently under high relative humidity in air. In the second study, the maximum particle penetration of five commercially available UDMs was evaluated against NaCl aerosol. Particle penetration was carried out as specified by National Institute for Occupational Safety and Health (NIOSH) to certify N95 FFRs (42 CFR Part 84). Particle penetration was found to vary between 3% and 75% at the most penetrating particle size. In addition, the effect of mass loading on BR of UDMs and FFRs over time was evaluated. ARD was used as the loading dust and BR was measured for 120 min on UDMs and FFRs. BR was found to increase differently between the tested UDMs and FFRs. Further analysis of the UDMs and FFRs external layer suggest that the development of the particle dust cake during mass loading may be influenced by differences of the external layer. In the third study, field research was conducted to evaluate BR of two N95 FFRs while performing power washing in swine rooms. A member of the research team wore the FFR while power washing swine rooms. Every 30 min the team member stopped power washing, BR was measured and power washing continued. At the end of the 120 min trial, the FFR model was switched and the team member continued to power wash the rest of the room. Results demonstrated that BR of the tested FFRs did not increased during power washing in swine rooms (FFR 1, p = 0.40; FFR 2, p = 0.86). Power washing was found to have an effect in the temperature and relative humidity inside the rooms. Based on this study, FFR wearer should expect no increase in BR over 8 hr of power washing, decrease health risk by wearing the FFR and no need to replace the FFR during the power washing task.

This work focuses on the cross-section between classic still-life art and complex personal issues. It uses traditional and nontraditional still life photography to tell individual vignettes about my life. I explore unresolved issues, which offer subtle suggestion of an experiential narrative. All of the backgrounds and objects included are intentional and represent specific places, people, and events. I allow the viewer to bring their own experiences to the photographs, by not giving them specifics of my stories. I used this work as a way for me to move past these experiences and my hope is that they might also help others. I have created beauty from my dwelling.

Chana Orloff, a prolific sculptor during the first half of the twentieth century, completed hundreds of portraits of her contemporaries during her lifetime. Scholars have examined these portraits more generally within the overall context of her work. Still, however, the scholarly discourse on the artist herself is limited, lacking an extensive analysis on the portraits themselves. Utilizing a selection of Orloff’s portraits, this thesis seeks to understand her work in terms of the reconciliatory role played by portraiture in expressing various aspects of the artist’s own identity. In particular, this analysis hopes to better understand the artist’s personal and professional contacts in Paris as well as in Palestine. As an artist, woman, and Jew, Orloff’s portraits grant insight into her own relationship with these categorizations and alignment with various trends within a feminist discourse as well as French and Zionist political movements. As such, this thesis takes into consideration multiple methodological approaches, making use of a bibliographical, formalist, feminist, and social art historical perspectives. Ultimately, this investigation hopes to reveal a fundamental intersection between Orloff’s self-conception and the characterization of her surroundings.

Aerosols are ubiquitous throughout Earth's atmosphere and their size, chem- ical composition, and concentration cause varying degrees of impact on climate and human health. Atmospheric aerosols can affect climate by their varied interactions with incoming solar radiation and their role in cloud formation and microphysics. Nucleation of fresh particles plays a significant role in the number of boundary layer cloud condensation nuclei (CCN). Elevated sulfuric acid concentration from power production has long been shown to contribute to new particle formation, but is not present in all instances where nucleation is observed. A third component has long been hypothesized and different studies in different locations have shown evidence of either ammonia, amines, or organics acting in conjunction with sulfuric acid and water to initiate new particle formation under certain meteorological conditions. While atmospheric nucleation has been examined world-wide in many urban as well as remote forested locations, it has not been studied extensively in the non-forested Midwestern United States, where sulfuric acid from coal-fired power plants and ammonia from agricultural activity are prevalent. For this doctoral dissertation work, instruments were designed, built, and tested for the purpose of investigating the concentration, size distribution, and volatility of atmospheric aerosols in non-forested rural continental environments in the Midwestern United States. An impact assessment of the University of Iowa Power Plant on air quality in Johnson County, IA highlights the ability to field test the emission ratios of fine particulates emissions to other gaseous emissions. Analysis on 20 years of climatically relevant aerosol properties in the rural Midwestern location of Bondville, IL reveals enhancement of particle number in the Spring and Fall seasons. Bondville is also the location of a three-year aerosol vertical profiling field campaign, where ultra-fine particles were found to be enhanced in the planetary boundary layer. The long standing records are compared with current full aerosol size distribution particle measurements for a period of ∼ 10 months in Bondville, where the seasonality of high particle number concentrations are verified and attributed to nucleation. Nucleation is observed to varying degrees in all seasons at this location, but is most prevalent and intense in the Spring and Fall months under otherwise clean atmospheric conditions. This work paves the way for a more in depth examination of the volatility of fine particle matter during nucleation and the development of a Midwestern chemical nucleation model to investigate numerous nucleation conditions and mechanisms. This work will contribute important information to the atmospheric science community on the process controlling the particle number size distribution in the region.

My work is defined by where I reside at the time of its creation. I am interested in exploring my own sense of place based on my curiosity with the unique character and history of my surroundings. The work discussed here is specifically concerned with the landscapes, communities and development practices prevalent throughout the Midwest. In my work I use my own personal experiences with disorientation and dislocation in the various suburban, urban and rural landscapes I encounter in my everyday life and share them with a wider audience. In that way they can place themselves within the ambiguous landscape I choose to depict and recall that it happens everywhere throughout the United States. My work uses combinations of printmaking, drawing, installation, book arts, and video art to express these themes.

A recently proposed set of demagnetization diagnostics [Scudder et al., submitted to Physics of Plasmas, 2015] is related to the preconditions of Guiding Center Theory (GCT) and benchmarked in kinetic particle-in-cell simulations. Specifically, GCT requires that the time and length scales of the field are long compared to the Larmor motion of the particles. When this condition is violated, the particles become demagnetized and the assumptions of magnetohydrodynamics are no longer valid. In this thesis, these diagnostics are applied to different space plasma layers of different length scales. In the past, proxy diagnostics that are not based on fundamental GCT conditions have been used to search for, and provide evidence of, demagnetization in different space plasma layers. The problem with these proxy diagnostics is that they are not invertible to demagnetization. The diagnostics presented in this thesis are not only unique to demagnetization, but also have the additional advantages of being dimensionless, scalar, and independent of coordinate system. These diagnostics are applied to three space plasma layers of different length scales, resulting in new insights and methods for detecting particle demagnetization. First, the evidence for wave heating in the solar wind is reexamined through its fundamental assumptions of demagnetization. The proxy diagnostic commonly used for demagnetization is non-conservation of the Chew-Goldberger-Low conserved quantity. This diagnostic is a good proxy for the first adiabatic invariant in the supersonic regime. To test this and compare it to the assumptions of the Helios analysis [Marsch et al., Journal of Geophysical Research: Space Physics, 88(A4), 1983], the solar wind is modeled through a self-consistent Vlasov mapping. In addition, other experimental assumptions in that same Helios analysis are also examined. Second, a new method for estimating local length scales is demonstrated across a known bow shock crossing. This new method, based on one of the demagnetization diagnostics, is different from current methods in that it can be performed with single spacecraft data and does not require a special coordinate system. Third, a new set of invertible signatures of the electron diffusion region (EDR) is introduced and applied to five magnetopause events to search for layers of collisionless magnetic reconnection. Four of these magnetopause events have not been identified before in the literature. The five EDR diagnostics are large electron pressure anisotropy, non-perturbative GCT expansion parameters, order one electron pressure agyrotropy, and order one electron thermal mach number. These EDR diagnostics are compared to a wide range of degenerate diagnostics that are commonly used in reconnection studies. The results of this analysis show that, compared to these degenerate diagnostics, the EDR diagnostics are much more surgical in their identification of electron-scale current layers.

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