Density Demonstration Projects: Strategies for Improving Asphalt Pavement Density

Knowing that in-place density is key for building cost effective and durable asphalt pavements, the Federal Highway Administration (FHWA) initiated the "Enhanced Durability of Asphalt Pavements through Increased In-place Pavement Density" demonstration project. The aim was to support State Departments of Transportation (DOTs) with evaluation of their existing density requirements for acceptance. It was anticipated that the results may aid State DOTs in reviewing and updating, as needed, their current field density acceptance criteria.United States Department of TransportationFederal Highway Administratio

Phosphate-Based Dechlorination of Electrorefiner Salt Waste using a Phosphoric Acid Precursor

Electrochemical processing of spent nuclear fuel in molten chloride salts results in radioactive salt waste. A growing global energy demand has revitalized interest in nuclear energy technology. With increasing quantities of used nuclear fuel (UNF), the Department of Energy (DOE) launched the “Converting UNF Radioisotopes Into Energy” (CURIE) program in 2022, providing resources for projects focusing on advancing UNF recycling technologies, including advanced non-aqueous methods like electrochemical reprocessing. Projects supported by the CURIE program will aim to reduce the volume of high-level waste (HLW) that will require permanent disposal and will also potentially provide feedstock that could be used in domestic advanced reactors. To that end, salt partitioning is an effective way to reduce HLW volume before long-term repository storage.Chlorine removal from the salt waste has been identified as an effective and efficient first step in the management of this and volume reduction of this HLW. Cl removal from the salt waste stream also aides in the waste form process as Cl solubility in the baseline oxide glasses like borosilicate glass tends to be very low, and the capacity of baseline mineral waste form options such as sodalite and apatite have very limited Cl capacities. In this work, a simple salt was dechlorinated with a phosphoric acid phosphate precursor, resulting in a glassy dechlorinated product. Because it is unknown if these processes would be conducted in a hot cell with an air or argon environment, dechlorination efficacy was evaluated in both environments. It was found that dechlorination was possible in both air and argon environments, although atmospheric oxygen appeared to play a significant role in the process. To evaluate temperature and atmosphere dependence on the extent of dechlorination, scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) and powder X-ray diffraction (XRD) was performed on the intermediate products formed under different temperature conditions for each atmosphere. Thermogravimetric analysis (TGA) and evolved gas analysis (EGA) were used to understand the off-gas behavior during dechloination under different processing conditions (e.g. heating profile and environment). This work serves as an initial step to advance the Technological Readiness Level of H3PO4-based dechlorination step towards implementation of iron phosphate waste forms to immobilize electrochemical fuel reprocessing salt waste streams. Sections of this thesis are verbatim reproduced from the study published by the American Chemical Society in the journal ACS Omega (“Phosphate-Based Dechlorination of Electrorefiner Salt Waste using a Phosphoric Acid Precursor”)

Border-Lines, Volume I

Border-Lines is an interdisciplinary and intersectional academic journal dedicated to the dissemination of research on Chicana/o-Latina/o cultural, political and social issues. Border-Lines is a refereed journal that seeks to publish scholarly articles drawn from a variety of disciplines such as anthropology, education, geography, human health, literary and cultural studies, political science, social work and sociology.Border-Lines is an interdisciplinary academic journal dedicated to the dissemination of research on Chicana/o-Latina/o cultural, political, and social issues. The journal seeks to publish scholarly articles drawn from a variety of disciplines such as Anthropology, Education, Geography, Public Health, Literary and Cultural Studies, Political Science, Social Work, and Sociology

Border-Lines, Volume XV

Border-Lines is an interdisciplinary and intersectional academic journal dedicated to the dissemination of research on Chicana/o-Latina/o cultural, political and social issues. Border-Lines is a refereed journal that seeks to publish scholarly articles drawn from a variety of disciplines such as anthropology, education, geography, human health, literary and cultural studies, political science, social work and sociology.This volume showcases works by authors with a focus on emerging Hispanic-Serving Institutions (HSIs) to address celebrations and opportunities along the journey of attaining an HSI designation by the U. S. Department of Education. Border-Lines, Volume XV aligns with the University of Nevada, Reno's vision of becoming an HSI

The Causes and Consequences of Complex Behavioral Trait Variation in a Resident Montane Bird

The causes and consequences of complex trait variation are of broad interest in the field of behavioral ecology. In the wild, animals experience wide ranging environmental conditions, and understanding the impact of this heterogeneity in shaping behavioral traits, such as cognition, is critical to understanding their evolution. Though it is thought that environmental conditions contribute to large inter- and intra-species variation in cognitive abilities, the mechanisms generating this variation remain poorly understood. Past laboratory-based work has shown that energetically expensive cognitive traits are impacted by developmental perturbations such as non-optimal developmental conditions (e.g. poor parental care, low-quality nest environment, etc.), but whether these same patterns are exhibited in natural populations is relatively unstudied. This dissertation provides novel insights into the mechanisms shaping complex behavioral trait variation in wild systems focusing on two behavioral traits, spatial cognitive abilities and nest building, in free-living mountain chickadees ( Poecile gambeli ). Chapter 1 describes the role of directional natural selection acting on spatial cognitive ability using a cohort comparison approach in a wild population. This study showed that spatial cognitive ability does not change within individuals across years, that adult birds on average performed better than first-year birds, and that members of a first-year cohort that performed worse on a spatial cognitive task were less likely to survive than those with better performance. This is some of the first evidence of natural selection acting on a cognitive trait in the wild. Chapter 2 investigates causes and consequences of variation in nest size in chickadees at different montane elevations with different climatic conditions. This study showed a large degree of temperature variation across all nestling developmental periods and between elevations, but this variation was unrelated to nest size or reproductive output in chickadees. This result contrasts results from studies in other populations of cavity-nesting birds that appear to construct nests corresponding to local environmental conditions. However, I found that female chickadees build highly repeatable sized nests across years. High repeatability in behavioral traits implies a heritable component, suggesting that female nest size is controlled by an innate mechanism. Chapter 3 considers variation in nestling immune response, ectoparasite load, and nest composition to determine how these developmental conditions shape behavioral trait variation. Ectoparasites are known to have fitness consequences for their hosts, but there is mixed evidence of how widespread and impactful these effects are on the traits of developing avian nestlings. I found that there was no relationship between greater ectoparasite infestation in the nest and offspring mass or immune response, seeming to indicate that this aspect of nestlings' developmental environment may not drive future behavioral trait variation. However, I did find that nest composition—including overall size (i.e., mass), amount of plant materials, and amount of animal materials (i.e., animal hair)—was highly repeatable within individual females, strengthening the evidence that individual variation in nest building behavior is heritable. Identifying potential post-fledging consequences related to parasite load remains understudied. Chapter 4 builds upon the work of my earlier chapters by investigating the underlying mechanisms that result in observed chickadee nest repeatability. I found evidence that apparent non-functional trait variation may be related to variation that is under selection through potential shared physiological mechanisms. In this study, I found that food-caching propensity and nest building propensity are not only highly repeatable behaviors within individual female chickadees but also highly correlated. This suggests that food caching, a trait under selection that has a strong underlying drive, may be directly affecting an unrelated behavioral trait, nest building, through a shared mechanism, resulting in a potential behavioral syndrome. Lastly, chapter 5 presents data testing whether there is a relationship between the physiological burden during offspring development and spatial cognitive abilities, which could explain some of the existing variation in cognitive abilities in wild food-caching mountain chickadees. I used ptilochronology (feather growth rates reflecting nutritional intake) and amount of corticosterone (a hormone associated with broad metabolic processes including stress responses) in feathers (Cortf) of juvenile chickadees to estimate the variation in developmental condition. I found that developmental variation had a limited effect on spatial cognitive abilities, suggesting potential compensatory mechanisms that buffer these specialized cognitive abilities critical for survival in food-caching chickadees from harmful ontological perturbations

Comparison of Marshall Compactor and Superpave Gyratory Compactor for Mix Design and Control of Airport Asphalt Mixtures

The Federal Aviation Administration’s (FAA) current Advisor Circular “Standard Specifications for Construction of Airports” No. 150/5370-10H (2018) allows the engineer to select compaction by either the Marshall hammer or Superpave Gyratory Compactor (SGC). The specifications require a compaction level of 50 blows or gyrations for asphalt mixtures for airfield pavements serving aircraft of 60,000 pounds or less, and 75 blows or gyrations for mixtures to support aircraft weighing more than 60,000 pounds, respectively. The Marshall hammer compaction was used for many decades prior to the development of the SGC and has been considered to result in mixtures with satisfactory performance. However, since the introduction of the SGC as an option in the FAA Advisory Circular in 2014, the SGC has gradually become the method of choice for most FAA projects. Some concern remains among many airfield asphalt pavement engineers that specimen densities from Marshall and SGC compaction are not equivalent, and the differences result in airfield asphalt mixtures that may perform differently in service.The goal of this research was to determine the equivalent number of SGC gyrations (Neq) that achieve volumetric mix properties equivalent to 50 and 75 blow Marshall hammer specimens. The research consisted of sampling 14 FAA hot mix asphalt (HMA) mixtures from 8 states. The sampled mixtures all conformed to FAA “Standard Specifications for Construction of Airports” No. 150/5370-10H (2018) with both P-401 and P-403 mixtures sampled. These mixtures varied in design with 6 mixtures designed with Marshall hammer compaction and 8 mixtures designed with SGC compaction. The sampled mixtures were tested by compacting via the Marshall hammer method to the specified number of blows based on FAA mixture type. The samples were then compacted via SGC to the specified number of gyrations. The volumetric properties of the compacted specimens were determined, and additional specimens were compacted via the SGC to bracket the volumetric results of the Marshall hammer compacted specimens. By correlating the results, the equivalent number of SGC gyrations (Neq) was determined for 50 and 75 blow Marshall hammer compacted samples. The result show that a Neq value of 87 gyrations with a standard deviation of 19 gyrations is equivalent to 75 Marshall blows for FAA P-401 and P-403 mixtures. Various mixture properties of the sample mixtures were compared to determine which properties have the greatest effect on the Neq value. Voids in Mineral Aggregate (VMA) has the highest correlation to Neq values. A Neq value for 50 blow Marshall mixtures was unable to be determined due to insufficient data

Under a Brilliance of Stars

A novel

A Biological Distance Analysis of 19th -20th -Century Individuals From Myanmar

Myanmar (Burma) is the largest country in mainland Southeast Asia that is an optimal region for studies in human migration patterns in the geographic area. However, owing to a regime under an isolationist military dictatorship for the last half-century, Myanmar is a relatively underrepresented country in the international sphere in many aspects, including anthropological research that explores the biological diversity of the country's human population. As such, the current dissertation study aims to: 1) examine the biological diversity in a sample of individuals belonging to a cranial collection obtained from Burma over a century ago (the Duckworth Burma cranial collection at the University of Cambridge); and 2) explore evolutionary trends in skeletal and dental morphology from this population sample. This research is a holistic and multi-faceted study that incorporates multiple data types (metric and nonmetric data) of the cranium and dentition to compare individuals from the Duckworth Burma collection to diverse global population groups. Results from the current study indicate that the Duckworth Burma crania exhibit phenotypic diversity that is reflective of their population history. Linear discriminant analysis results of metric suggest that the Duckworth Burma samples were skeletally closest to individuals from Java (Indonesia), South India, and the Philippines. Cluster analyses of craniometric data also showed distinct clusters that formed independent of sexual dimorphism, suggesting phenotypic diversity within the Burma groups analyzed. Further, samples from the Duckworth Burma collection exhibit craniofacial dimensions and traits that are consistent with traits associated with warmer climates. Both craniometric canonical variate plots and macromorphoscopic (MMS) trait frequency analyses of the Duckworth Burma samples indicate closer relationships of this group with other population groups associated with warmer climates. Moreover, raw cranial measurements and MMS trait scores of the Duckworth Burma individuals further support the findings based on climate-related craniofacial morphology. Lastly, the overall results from various data types demonstrate that samples from the Burma groups analyzed in this study are most similar to other Southeast, East, and South Asian population groups, following the isolation-by-distance model. The current dissertation is the first biological distance (biodistance) study in over 100 years to revisit the Duckworth Burma cranial collection and give it the attention it deserves. Moreover, it is also the first biological anthropological study conducted on Burmese remains by an anthropologist belonging to the Burmese diaspora who is also a descendant community member of the Duckworth Burma individuals. Knowledge produced from the current study can aid in future data collection on additional skeletal samples from Myanmar. Further, it can also serve as a referential baseline for the forensic identification of individuals in Myanmar whose remains have been fully decomposed, skeletonized, or thermally altered due to the atrocities committed by the military junta. As such, this dissertation study strives to serve as a small yet crucial step in bridging an immense gap between biological anthropology and Myanmar

Alfalfa Aphids From Pixel to Picture: Deciphering Symbiotic and Predatory Interactions Across Scales

Alfalfa is the cornerstone of Nevadan agriculture. Together with alfalfa aphids, these organisms exemplify the complex ecology of herbivory. This dissertation explores multiple dimensions of this ecology: the landscape context of aphid predation and biocontrol, interactions between the microbial symbionts of alfalfa and aphids, and the factors influencing the occurrence of aphids' secondary bacterial endosymbionts. Chapter 1 focuses on pest control of alfalfa aphids using natural predation. In this study, we applied remote sensing and distance-weighted spatial analysis to determine the sizes, types, and arrangements of habitats that were most beneficial to predators. We paired this study with exclosures to estimate the true effects of predators on aphid population control. We found that coccinellid beetles, which are key aphid predators, were associated with weedy cover in and around alfalfa fields. Our results suggest that weedy areas may provide an undervalued ecosystem service to alfalfa farmers. Chapter 2 explores the potential interactions between the legume-rhizobia and aphid- Buchnera mutualisms. Both rhizobia and Buchnera transform nitrogen into forms that can be assimilated by their hosts and modulate the expression of host plant defense. Yet, the potential nutrient- or plant defense-mediated effects of rhizobia on Buchnera have never been examined. The experiments described in chapter 2 show that nutrient-mediated processes can affect Buchnera , and pave the way for future experiments that directly address rhizobia's nutrition-mediated effects. Aphids also form facultative symbiotic associations with several other types of bacteria, and these symbioses are the subject of chapter 3. In this chapter, we examined the factors that shape the occurrence of facultative symbionts across a broad range of alfalfa habitats. We leveraged a survey of alfalfa traits and arthropod occurrence that spanned 56 sites and seven states across the western US. In a subset of these sites, we sequenced DNA from aphid extractions to identify secondary symbionts and model their occurrence. Importantly, we identified intraspecific host plant variation as a key predictor of symbiont occurrence—a factor that has been largely overlooked in previous work. In summary, this dissertation extends our knowledge of alfalfa and alfalfa aphids in several directions, including aphid biocontrol, interactions between alfalfa and aphid mutualisms, and the distribution of aphid facultative symbionts. It combines experiments and observational studies, extends across spatial scales, and embraces a wide range of techniques to explore the unique ecology of these organisms

Human Suboptimal Choice: Identifying Alternative Procedures

Suboptimal choice refers to choices that result in leaner schedules of reinforcement over richer schedules (Spetch et al., 1990). This has been demonstrated with non-human animals using procedures wherein two alternatives correspond to different stimuli and different probabilities of receiving rewards. In a previous study (Cronin, 1980), pigeons engaged in suboptimal choice when stimuli paired with food (conditioned reinforcers) followed responses that resulted in no food. This effect, though, has not been demonstrated with humans. The present study aims to replicate the results of the Cronin (1980) study to determine whether the manipulation of stimulus presentations could result in suboptimal responding with humans. This data could provide information regarding the components that maintain suboptimal choice with humans