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High Altitude Labyrinth Design and Construction
No full textGEI worked with a Colorado district to design and construct a labyrinth spillway at a high-altitude reservoir west of Denver. The labyrinth spillway increased the reservoir normal water surface elevation 10 feet, increasing reservoir storage capacity by 120 acre-feet. This additional storage was achieved with the labyrinth with minimal modification to the existing embankment dam. The site presented challenges including significant ice loading on the weir structure, complex rock conditions requiring seepage control measures, and unique construction techniques.
A labyrinth weir configuration was chosen to increase discharge capacity with minimal adjustment to the existing spillway footprint and to pass the Inflow Design Flood with the higher water surface. Empirical design methods were used to develop the labyrinth weir geometry. The spillway has 3 cycles and is 92 feet wide and 111 feet long. This paper presents a comparison of the recent computational fluid dynamics modeling and the spreadsheet-based results
Empower Yourself Through Self-Defense: Enhancing Personal Safety Through Self-Defense Education
No full textThe Empower Yourself Through Self-Defense program, developed by Utah State University faculty in 2024, builds participants’ confidence by equipping them with self-defense knowledge and skills. Participants reported reduced fear, increased preparedness, and strong interest in continued training. The program enhances personal safety by empowering individuals with practical skills for self-protection
Diverse Dust Sources and Warming Trigger Cyanobacteria Abundance in Freshwater Ecosystems in the Western United States
No full textThe rise in global temperature and the increase in atmospheric transport and deposition of dust linked to greater aridity, land abandonment, and wildfires, are placing significant stress on freshwater microbial communities. Temperature increases and the nutrients contained in the dust may independently and together alter the metabolism and structure of these communities. However, dust chemistry is widely variable, and pre-existing lake conditions will likely influence the response of the algal and microbial communities to added nutrients and temperature stress. To fill this gap of knowledge, we tested the metabolic and structural response of phytoplankton in two aquatic ecosystems in the Western United States (Half-Moon Lake and Jordanelle Reservoir), which have similar trophic status but different biogeochemical properties, in response to two types of atmospheric dust from the region. The results show that the Temperature × Dust interaction led to greater cyanobacteria growth in Half-Moon compared to Jordanelle. The effect on metabolism also differed, with Half-Moon showing a tendency toward heterotrophy, while Jordanelle trended toward autotrophy. Interestingly, our study reveals that the direction of the response was mainly regulated by each ecosystem\u27s properties, while the magnitude of the response was controlled by the type of dust. Through this work, we demonstrate that oligotrophic freshwater ecosystems are sensitive to dust-nutrient additions leading to cyanobacterial blooms and highlight the importance of considering watershed biogeochemical properties and exposure to different types of dust in lake and reservoir management strategies
Combining Submicron Spectroscopy Techniques (AFM-IR and O-PTIR) to Detect and Quantify Nanoplastics in Snow From a Utah Ski Resort
No full textAtomic force microscopy-based infrared spectroscopy (AFM-IR) and optical photothermal infrared (O-PTIR) spectroscopy are cutting-edge techniques used for precise nanoscale chemical analysis, capable of detecting and characterizing particles smaller than 1 μm. In this study, we applied both techniques to analyze snow subsamples collected from Beaver Mountain, Utah. Quantification by AFM-IR identified a concentration of 1.50 × 10–1 μg/mL of poly(3-hydroxybutyrate-co-4-hydroxybutyrate), a copolyester known for its biodegradability and biocompatibility and that was the only polymer detected. Notably, 96% of particles had thicknesses below 1 μm, with the smallest particle recorded at 14 nm in height, demonstrating the advantage of the paired AFM-IR and O-PTIR techniques to detect and identify the chemical composition of a single nanoparticle. By integrating AFM-IR and O-PTIR, we combined the spatial resolution of AFM with the chemical specificity of O-PTIR, overcoming the limitations of each technique. This dual approach enabled high-sensitivity detection of nanoplastics in complex environmental samples with no preprocessing required. This approach provides valuable insights into the dimensions and concentrations of nanoplastics in environmental samples, with broader implications for understanding their prevalence and impact
Strategies for Increasing Methane Removal in Methanotroph Stirred-Tank Reactors for the Production of Ectoine
No full textMethane is a potent greenhouse gas that requires its emissions to be mitigated. A significant source for methane emissions is in the form of the biogas that is produced from anaerobic digestion in wastewater reclamation and landfill facilities. Biogas has a high valorization potential in the form of its bioconversion into ectoines, an active ingredient in skin care products, by halotolerant alkaliphilic methanotrophs. Cultures of Methylotuvimicrobium alcaliphilum 20Z were grown in bench scale stirred-tank reactors to determine factors to improve methane uptake and removal. Tangential flow filtration was also implemented for a bio-milking method to recover ectoine from culture media. Methane uptake and reactor productivity increased, with a temperature of 28 ◦C compared with 21 ◦C. Decreasing the methane gas bubble diameter by decreasing the sparger pore size from 1 mm to 0.5 µm significantly improved methane removal and reactor productivity by increasing mass transfer. Premixing methane and air before sparging into the reactor saw a higher removal of methane, while sparging methane and air separately created an increase in reactor productivity. Maximum methane removal efficiency was observed to be 70.56% ± 0.54 which translated to a CH4-EC of 93.82 ± 3.36 g CH4 m−3 h −1 . Maximum ectoine yields was observed to be 0.579 mg ectoine L−1 h −1
Intergenerational Transfers in a Tractable Overlapping-Generations Setting
No full textMotivated by the Generation-Skipping Transfer Tax (GSTT) in the United States, we examine how varying estate tax rates by the heir’s age affects welfare. Methodologically, we introduce a parsimonious constant elasticity of substitution (CES) bequest utility that is markedly more tractable than the altruistic specifications commonly used in the literature, delivering closed-form optimal rules and transparent parameterization. Using this new framework, we provide a proof of concept showing how transfers from older to younger generations can enhance equilibrium welfare in a dynamically efficient economy à la Samuelson (1975). We embed the tractable bequest utility in a two-period overlapping-generations model with age-dependent estate tax schedules. Numerical exercises—parameterized to the fact that estate tax revenue is small relative to labor income taxation—indicate that lowering the tax rate on bequests to younger heirs (grandchildren) relative to older heirs (adult children) raises the present value of lifetime resources and overall welfare, effectively reversing the logic of the current GSTT. The findings highlight a practical avenue for implementing a “reverse social security” transfer from old to young that can improve welfare in dynamically efficient economies
ENG- SEMICON: Understanding Nanoscale Heat Transport in Wide- and Ultrawide Bandgap Semiconductors Using Novel Deep Ultraviolet Tools
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Water Rights Accounting and Distribution in Utah
No full textThis white paper summarizes how the Utah Division of Water Rights (WRi) administers water rights through the coordinated processes of water distribution and accounting. Water distribution involves apportioning divertible flow in river systems by adjusting diversions and reservoir storage. To account for and distribute water effectively, WRi must first determine the amount of water available for diversion each day, then prioritize water rights when water supply is insufficient to satisfy all demands. WRi has developed specialized tools and models to support this process.
This paper was developed through a collaboration between WRi and Utah State University to produce a report describing Utah’s current water distribution and accounting practices. It explains the rationale, methods, and assumptions behind current practices, presents case studies and examples within the state, and explores how recent legislative changes reinforce accurate and transparent water distribution and accounting practices. The goal is to promote greater understanding and transparency of water distribution and accounting practices for water right holders, policymakers, WRi staff, and the public