8413 research outputs found
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Reflective Essays on Archaeology’s Engagement with Neme (Northern Paiute) Tribal Cultural and Heritage Management
No full textAbstractThis dissertation takes an autoethnographic approach to the experiences of the author, a Neme Mogo’ni (Paiute woman) practicing and researching in archaeology, anthropology, and western philosophy over the last four decades. My knowledge and experience allow for a unique perspective. I provide insights and facilitation between mainstream US understandings of tribal culture and heritage as juxtapositioned with traditional Neme (Northern Paiute) understandings of tribal culture and heritage needs and concerns
The Nonverbal Communication of a Conductor: The Bonner Method
No full textThis thesis explores the conducting methods and philosophies of Dr. Gary Bonner, who has been an influential choral conductor and educator for over six decades. Bonner’s unique approach, referred to in this document as the “Bonner Method,” emphasizes leadership through relationships, and placing trust between the conductor and key ensemble members for effective nonverbal communication. Bonner’s conducting places significant importance on using space, energy, freedom and motion to achieve an energized and expressive choral tone. Throughout his career, Bonner has encouraged conductors to move beyond the conducting pattern to create a higher level of artistry. For conductors who use the Bonner Method, this philosophy is known as the “Less is More, If It’s Enough” principle. This research will also show how Bonner’s techniques encourage conductors to explore artistic freedom and interpretation by changing music and interpretations in real-time. The project will also describe specific Bonner Method gestures that can be applied to additional choral strategies, such as tone placement and vowel modification, to improve optimal resonance and sound production. As the current literature on choral conducting remains sparse, compared to orchestral conducting, this thesis aims to fill that gap by providing a detailed analysis of Bonner’s methods. Through interviews and first-hand accounts, it will offer valuable insights for modern conductors seeking to integrate nonverbal communication and artistic interpretation into their work
Case Studies for Risk Assessment of Superheavy Load Movements on Flexible Pavements using SuperPACK
No full textThis dissertation investigates the evaluation of Superheavy Load (SHL) movements on flexible pavements using the SuperPACK software, an analysis tool developed at the University of Nevada, Reno (UNR). SHL vehicles, characterized by their low travel speeds, extreme gross weights, and unique configurations, pose significant challenges to pavement integrity and safety. This research employs a paper-based format comprising three distinct case studies, each addressing key aspects of SHL impacts: the analysis of unbound layer shear failure under heavy aircraft loading, the identification of critical pavement sections using deflection metrics, and the utilization of traffic speed deflectometer (TSD) measurments for identifying and characterizing critical pavement locations that are most susceptible to failure under the imposed load of an SHL vehicle. These Pilot case studies illustrate the SuperPACK methodology's application while highlighting its computational efficiency and practical value. Through rigorous data analysis and mechanistic modeling, this work contributes to enhancing infrastructure resilience, advancing mechanistic pavement evaluation techniques, and supporting the adoption of risk-based permit processes for SHL vehicle moves
Microplastics occurrence and distribution in two western arid river systems: the Truckee River and the Lower Colorado River
No full textMicroplastics (MPs) have been classified as an emerging contaminant and are ubiquitous throughout the environment, especially in marine and freshwater aquatic systems. While many studies concerning MPs have been conducted in marine and freshwater lake environments, few have been conducted in arid riverine systems. Additionally, there has been a call from the MPs community to investigate the impact of seasonality and discharge rates upon MP contamination of freshwater systems. In this study, we sought to quantify and characterize MPs in the Truckee River, an internally draining freshwater river system, in the arid U.S. states of Nevada and California and the Lower Colorado River basin. The Lower Colorado River flows from the U.S. and forms the interstate border between California and Arizona and the international border between Mexico and the U.S. Due to the geographic location and flow direction of the Lower Colorado River, these flows have the potential to transport MP particles across international borders. Both rivers flow through a variety of land uses and portions of tribal land areas, are used for drinking water, and receive inflows of treated wastewater. Because the rivers are utilized for their drinking water, recreation, and serve as important aquatic habitats, assessing the MPs present in these systems is essential for determining risk to human and aquatic health. Plastic chemical identification was conducted using microscope enabled µ-Fourier Transform Infrared Spectroscopy (µFTIR). Results from these studies are compared to MP work in the surrounding land areas and MP studies conducted on freshwater river systems. MPs were found in both the Truckee River and the Lower Colorado River. Concentrations increased with anthropogenic impact downstream along the Truckee River, while MP concentrations showed less change in concentration moving downstream along the Lower Colorado River. Moreover, seasonal flow changes appeared to increase the concentrations of MPs found within the Truckee River samples. This work will inform potential sources of MPs to freshwater river environments, help to explain seasonal variability of MP concentrations in arid freshwater systems, and aid in the understanding of the international impact of MPs contributed by the Lower Colorado River to Mexico.
Border-Lines, Volume VII
No full textBorder-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
Investigation and Improvement of the Low Temperature Performance of High-Capacity Silicon Anodes for Lithium-Ion Batteries
No full textThe behavior of a lithium-ion battery is highly influenced by its operating temperature. Kinetics of lithium intercalation may improve upon increased temperature or become sluggish when the temperature is lowered. Many physical properties and reactions within the cell during discharge contribute to poorer performance at low temperatures such as increased viscosity and loss of conductivity of the electrolyte, increased impedance across SEI layers, and a propensity to plate lithium on the anode surface. Performance of these batteries starts to show significant deviation from room temperature at about 0°C and below. The demands of future generations of lithium-ion batteries for Martian rovers, satellites and other aerospace applications require retaining high capacity at -60°C and -80°C so temperatures of -20°C to -40°C are chosen initially to investigate next generation electrodes. The effect of various electrolytes on lithium-ion battery performance at low temperatures has been the most widely studied aspect in improving discharge characteristics, and a trend of mixed carbonates with various additives has been established. These additives help improve conductivity of the electrolyte and facilitate more stable SEI growth. Ether based organic solvents have also emerged as promising electrolytes, imparting greater stability and faster kinetics in lithium-ion cells at low temperatures. Focus for improving performance is not just on the electrolyte however, as electrode processing also plays a role in electrochemical behavior. Size of electrode particles, type of binder used and any possible heat treatments to the electrode all impact the cells performance. The most common anode material used in lithium-ion batteries today is graphite, with a theoretical capacity of 372 mAh/g. In an economy shifting more towards renewable energy, not only is higher energy density more pertinent, but higher capacity anode materials are needed to function across lower temperatures as well. Anodes containing silicon, with a capacity of 4200 mAh/g, are the most studied higher capacity anode with the potential to replace graphite. How the silicon electrode is processed is important to achieving high capacity in a lithium-ion cell as volume expansion and loss of particle contact are major issues to mitigate. This is why physical characteristics such as particle size, choice of binder, additive for structural integrity and heat treatment steps are considerations that need careful examination for improved anode performance. Concerning the electrolyte, fluorinated additives are becoming more known to facilitate stable and robust SEI formation, and ethers, instead of carbonates, may offer protection against lithium plating when using lithium metal as anode (3860 mAh/g) or in full cells with relatively low voltage requirements. After initial experimentation with traditional lithium-ion cells at -20°C to examine low temperature behavior and trends, the main chemistry examined was a copper modified silicon electrode paired with lithium metal counter electrode. Various electrode processing methods of the silicon electrode were investigated along with different electrolyte formulations to improve low temperature performance at -20°C, -30°C and -40°C over traditional graphite-based lithium-ion batteries. Several analytical techniques revealed how performance of the silicon electrode at low temperatures is directly related to fabrication methods and how choice of suitable electrolyte can lead to retaining high discharge capacities for long cycle life testing
Border-Lines, Volume VIII
No full textBorder-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
Minamata on the ground: preventing mercury exposure and advancing measurement methodology
No full textMercury (Hg) is a highly toxic global contaminant that is primarily released to the environment through anthropogenic activities. To protect the environment and human health, the United Nations ratified the Minamata Convention in 2013. Atmospheric oxidized Hg (HgII) measurement and chemical characterization methodologies are currently an important area of research supporting Minamata Convention-related policies because HgII deposition is a significant pathway by which Hg pollution enters ecosystems. Preventing Hg exposures to humans during industrial processes is also an important objective for research supporting Minamata Convention goals. The first portion of this work seeks to advance HgII measurement methodologies by identifying and validating novel surfaces for quantitative HgII preconcentration and chemistry analysis by mass spectrometry methods. Chitosan, α-Al2O3, γ-Al2O3, calcium phosphate glass (CaP), iron phosphate glass (FeP), and crystalline calcium aluminate (CaAl) were investigated for quantitative HgII and Hg0 capture in laboratory and field settings. Although chitosan, α-Al2O3, and γ-Al2O3 selectively sorbed HgII, but not Hg0, these materials did not capture as much ambient HgII as co-deployed cation exchange membranes (CEMs) in the field. CaP, FeP, and CaAl were found to quantitatively sorb permeated HgBr2 in the laboratory but did not retain permeated HgBr2 during field deployment. CEMs were also found to lose a significant percentage of pre-loaded HgBr2 during field deployment. The thermal desorption profile of HgBr2 permeated on nylon membranes was found to vary by membrane manufacturer. More work is needed to determine if CaP, FeP, and CaAl can be quantitatively deployed in the field, and if HgBr2 can be used in field conditions as a reliable proxy for atmospheric HgII compounds.
The second portion of this work explored the potential for human and livestock exposure to Hg, selenium (Se), arsenic (As), and cadmium (Cd) if contaminated wastewater is utilized in Arthrospira maxima and Chlamydomonas reinhardtii aquaculture. Utilizing wastewater for cultivation may increase the sustainability of microalgae production by reducing costs and decreasing the water footprint. However, microalgae cultivation in wastewater may also expose consumers or cultivators to contaminants. A. maxima and C. reinhardtii were grown under controlled laboratory conditions in microcosms and exposed to Hg, As, Se and/or Cd. Using a mass balance approach, elements were quantified in the gaseous, liquid, and biomass phases to determine movement of contaminants from growth medium to biomass and gaseous compartments following microalgae growth. No significant volatilization of Hg, As, Se, or Cd occurred, although Hg, As, and Se were recovered in C. reinhardtii biomass. A. maxima was found to sorb significant portions of Hg and Cd, indicating that these microalgae could expose consumers to toxic elements if grown in contaminated medium
Advanced Mobility and Safety Analytics Applications Using High-resolution Vehicle Trajectory Data
No full textThe increasing availability of high-resolution vehicle trajectory data has opened new ways for advancing mobility and safety analytics in transportation research. This dissertation explores the application of such data across three critical areas: traffic signal timing, complete streets design, and driver behavior at roundabouts. Each application addresses a gap in current methodologies by leveraging automated vehicle trajectory data to enhance traditional evaluation techniques.First, this research presents a method for evaluating traffic signal timing performance using vehicle trajectory data to determine the minimum number of travel runs required to evaluate its performance. Through cluster analysis and probability, the study offers an approach to balance resources demands for floating-car investigations while maintaining robust performance evaluation. The final recommendation is to perform five travel runs per direction per timing plan.
Second, the dissertation examines the effectiveness of complete streets design (CSD), which aims to provide safe access for all people in roadways and related infrastructure. This research analyzed driver speed and acceleration/deceleration behavior across three Nevada corridors with varying levels of CSD implementation, as well as deceleration rates at crosswalks for both CSD and partially implemented CSD corridors. Results indicate that both CSD and non-CSD corridors exhibited 85th percentile speeds significantly higher than the posted speed limits, and deceleration rates at partially-CSD crosswalks were significantly more aggressive than at fully-CSD crosswalks. These findings highlight the need to evaluate whether current CSD implementations are achieving their intended outcomes, especially regarding speed management and safety.
Finally, the study evaluates driver compliance and maneuvering behavior at multilane roundabouts using high-resolution trajectory data. By employing geofencing, trajectory classification, and behavior-based metrics, this work identifies distinct patterns between maneuver A, which follows road signage and markings, and maneuver B, which refers to trajectories that do not follow signage or road markings, potentially creating conflict points. Notably, maneuver type B were more frequent at approaches where single lanes transitioned into multiple lanes, creating ambiguity and increasing the likelihood of lane selection errors.
Together, these applications demonstrate the potential of high-resolution vehicle trajectory data to inform policy, optimize infrastructure, and support evidence-based design interventions aimed at safer and more efficient mobility systems
