RABRs for Use in Biologically Enhanced Precipitation of Struvite in Anaerobic Digester Effluent (Municipal Wastewater)

Rotating Algae Biofilm Reactor (RABR) technology has been researched in studies over the past decade directed at nutrient management for water resource recovery facilities (WRRFs). This study investigated the growth of slow-release fertilizer crystals, referred to as struvite, in the algae biofilms of Rotating Algae Biofilm Reactors (RABRs) at the Central Valley Water Reclamation Facility, the largest water resource recovery facility in the State of Utah. RABRs used anaerobic digester (AD) filtrate as their nutrient source. AD effluent is high in nutrients like nitrogen and phosphorus. The levels of both phosphorus and nitrogen (in the form of ammonia) are regulated by the State of Utah, and WRRFs must limit the amounts deposited into receiving waters including rivers, streams, and lakes. Struvite, being partially composed of both ammonia nitrogen and phosphorus, can help remove both elements from the water when it is formed by natural chemical precipitation. Because struvite is also an effective slow-release fertilizer, struvite formation helps treat wastewater, recycle phosphorus and ammonia nitrogen, and provide economic value from wastewater. RABRs were built as laboratory scale, bench scale, and pilot scale. AD effluent filtrate was analyzed to determine ion concentration data and this data was then used to calculate and predict struvite solubility over a range of pH values and used in computer modeling to predict likely precipitates. Chemical instrumentation including Scanning Electron Microscope (SEM) and Electromagnetic X-Ray Dispersion Spectroscopy (EDS) technologies were used to identify crystals in RABR biofilms and to determine their composition. Results of this research showed that struvite could precipitate at the pH values of the AD effluent filtrate. Further, high light intensity representative of sunlight increased the pH inside of the biofilms which enhanced struvite formation. Chemical instrumentation analysis by SEM/EDS showed that struvite had formed in the pilot RABR biofilm. It was also observed that the pilot scale RABR produced struvite within the biofilm when the biofilm was exposed to the atmosphere for a sufficient time to allow evaporation of water (at least 2 minutes). This research has demonstrated that struvite precipitation using RABRs can provide an innovative technology for nutrient management by WRRFs

A Multiresolution Stochastic Process Model for Predicting Basketball Possession Outcomes

Basketball games evolve continuously in space and time as players constantly interact with their teammates, the opposing team, and the ball. However, current analyses of basketball outcomes rely on discretized summaries of the game that reduce such interactions to tallies of points, assists, and similar events. In this paper, we propose a framework for using optical player tracking data to estimate, in real time, the expected number of points obtained by the end of a possession. This quantity, called \textit{expected possession value} (EPV), derives from a stochastic process model for the evolution of a basketball possession; we model this process at multiple levels of resolution, differentiating between continuous, infinitesimal movements of players, and discrete events such as shot attempts and turnovers. Transition kernels are estimated using hierarchical spatiotemporal models that share information across players while remaining computationally tractable on very large data sets. In addition to estimating EPV, these models reveal novel insights on players' decision-making tendencies as a function of their spatial strategy.Comment: 31 pages, 9 figure

Modeling three-dimensional acoustic propagation in underwater waveguides using the longitudinally invariant finite element method

textThree-dimensional acoustic propagation in shallow water waveguides is studied using the longitudinally invariant finite element method. This technique is appropriate for environments with lateral variations that occur in only one dimension. In this method, a transform is applied to the three-dimensional Helmholtz equation to remove the range-independent dimension. The finite element method is employed to solve the transformed Helmholtz equation for each out-of-plane wavenumber. Finally, the inverse transform is used to transform the pressure field back to three-dimensional spatial coordinates. Due to the oscillatory nature of the inverse transform, two integration techniques are developed. The first is a Riemann sum combined with a wavenumber sampling method that efficiently captures the essential components of the integrand. The other is a modified adaptive Clenshaw-Curtis quadrature. Three-dimensional transmission loss is computed for a Pekeris waveguide, underwater wedge, and Gaussian canyon. For each waveguide, the two integration schemes are compared in terms of accuracy and efficiency.Mechanical Engineerin

My Experience During COVID-19

This short essay describes what it has been like for me living as a student during COVID.https://www.exhibit.xavier.edu/covid19xu_documents/1007/thumbnail.jp

Typographic Interventions: Disruptive Letterforms in Public Space

We are surrounded by typography—on billboards, aluminum cans, pill bottles, and pixelated screens—but artists and art teachers, seeking out the materiality of their lived environments, should be able to look at text in different ways. Many artists utilize letterforms as a medium of juxtaposition and recontextualization (Gude, 2004) by placing text in places we don’t expect to see it, or they subvert the messages we expect to read. Typographic interventions can be seen everywhere, by all types of artists, makers, activists, and dissidents. These interruptions could be framed as forms of socially engaged art (Helguera, 2011; Mueller, 2020) that “suspend the flow of everyday life” (Spector, 2013, p.15). At times, these works offer a respite, a re-collection, and/or valuable critiques of the communities they inhabit (Helguera, 2011). This essay invites art educators to utilize letterforms as a material of provocation and interruption. The author sketches a few brief histories of typographic interventions, offers a few provocations for art educators, and provides some examples of student work as they respond to the proposition: Use letterforms to subvert a public space in a positive way