Physical Sciences and Mathematics Commons^™

Synthesis Of Β,Β-Disubstituted Styrenes Via Trimethylsilyl Trifluoromethanesulfonate-Promoted Aldehyde-Aldehyde Aldol Addition-Deformylative Elimination., Grant J. Dixon, Michael R. Rodriguez, Tyler G. Chong, Kevin Y. Kim, C. Wade Downey

Chemistry Faculty Publications

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, α,α-disubstituted aldehydes condense with electron-rich aromatic aldehydes to yield β, β- disubstituted styrenes. More electron-rich aromatic aldehydes react more rapidly and in higher yield. Preliminary results suggest that the reaction may proceed via the ionization and formal deformylation of an aldol intermediate.

One-Pot Synthesis Of 2-Methylfurans From 3- (Trimethylsilyl)Propargyl Acetates Promoted By Trimethylsilyl Trifluoromethanesulfonate, Danielle E. Sklar, Alex V. Helbling, Yiqi Liu, C. Wade Downey

Chemistry Faculty Publications

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, 3-(trimethylsilyl)propargyl carboxylates undergo a one-pot alkylation-cyclization- desilylation reaction with ketones to produce 2-methylfurans. Alkylation at 0 °C in methylene chloride, followed by acid-catalyzed cyclization at room temperature, provides the furans in 52-86% yield. Cyclization and desilylation appear to be promoted by triflic acid generated in situ from the exposure of the reaction mixture to water upon completion of the initial substitution reaction.

Friedel–Crafts Addition Of Indoles To Nitrones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Zachary Z. Oracheff, Helen L. Xia, Christopher D. Poff, Scott E. Isaacson, C. Wade Downey

Chemistry Faculty Publications

N-alkylindoles undergo Friedel–Crafts addition to aryl and secondary alkyl nitrones in the presence of trimethylsilyl trifluoromethanesulfonate and a trialkylamine to produce 3-(1- (silyloxyamino)alkyl)indoles. Spontaneous conversion to the bisindolyl(aryl)methanes, which is thermodynamically favored for nitrones derived from aromatic aldehydes, is suppressed under the reaction conditions. The silyloxyamino group can be deprotected with tetrabutylammonium fluoride to yield the hydroxylamine.

The Surface Diffusion And The Willmore Flow For Uniformly Regular Hypersurfaces, Jeremy Lecrone, Yuanzhen Shao, Gieri Simonett

Department of Math & Statistics Faculty Publications

We consider the surface diffusion and Willmore flows acting on a general class of (possibly non–compact) hypersurfaces parameterized over a uniformly regular reference manifold possessing a tubular neighborhood with uniform radius. The surface diffusion and Willmore flows each give rise to a fourth–order quasilinear parabolic equation with nonlinear terms satisfying a specific singular structure. We establish well–posedness of both flows for initial surfaces that are C^1+α–regular and parameterized over a uniformly regular hypersurface. For the Willmore flow, we also show long–term existence for initial surfaces which are C^1+α–close to a sphere, and we prove …

Asymptotically-Optimal Topological Nearest-Neighbor Filtering, Read Sandström, Jory Denny, Nancy M. Amato

Department of Math & Statistics Faculty Publications

Nearest-neighbor finding is a major bottleneck for sampling-based motion planning algorithms. The cost of finding nearest neighbors grows with the size of the roadmap, leading to a significant computational bottleneck for problems which require many configurations to find a solution. In this work, we develop a method of mapping configurations of a jointed robot to neighborhoods in the workspace that supports fast search for configurations in nearby neighborhoods. This expedites nearest-neighbor search by locating a small set of the most likely candidates for connecting to the query with a local plan. We show that this filtering technique can preserve asymptotically-optimal …

Topology-Guided Roadmap Construction With Dynamic Region Sampling, Read Sandström, Diane Uwacu, Jory Denny, Nancy M. Amato

Department of Math & Statistics Faculty Publications

Many types of planning problems require discovery of multiple pathways through the environment, such as multi-robot coordination or protein ligand binding. The Probabilistic Roadmap (PRM) algorithm is a powerful tool for this case, but often cannot efficiently connect the roadmap in the presence of narrow passages. In this letter, we present a guidance mechanism that encourages the rapid construction of well-connected roadmaps with PRM methods. We leverage a topological skeleton of the workspace to track the algorithm's progress in both covering and connecting distinct neighborhoods, and employ this information to focus computation on the uncovered and unconnected regions. We demonstrate …

Systems Of Meaning In Place Attachment, Emily Routman

Geography and the Environment Capstone Projects

Numerous scholars agree that contact with natural landscapes has benefits for the landscape and the person experiencing them, including increased environmentally-responsible behaviors as well as psychological, cognitive, physiological, and social benefits. People develop a sense of place in outdoor landscapes while experiencing the physical environment, and sense of place is strengthened by place attachment – one’s emotional ties to a place. According to Williams and Patterson (1999), place attachment is perceived through four systems of meaning: 1) aesthetic/inherent, 2) goal-directed/instrumental, 3) cultural/symbolic, and 4) individual/expressive. The present study sought to understand which of these four systems of meaning are the …

Tree Removal Analysis Of The 2018-2019 Gambles Mill Eco-Corridor Restoration, Zach Harrell

Environmental Studies Senior Seminar Projects

Trees have been extensively researched, and it has been concluded that they are useful not only useful tools in enhancing biofiltration, as well as managing stormwater and retaining sediment, but they also benefit the health of the ecosystem as a whole. But as the University of Richmond’s Gambles Mill Eco-corridor was restored between 2018 and 2019 in order limit to the amount of phosphorus, nitrogen, and other sediment flowing into the Little Westham Creek; many of the trees that combat these problems were removed. The following research intends to analyze the number of trees actually removed throughout the restoration, as …

Stream Restoration As A Method Of Improving Local Water Quality, Emily George

Environmental Studies Senior Seminar Projects

Projects of stream restoration are a known Best Management Practice (BMP) to approach stormwater management, and have been adopted globally as a means of improving local hydrology. Urbanization has led to an increase in impervious surfaces, resulting in deteriorated streams, many of which are subject to stream restoration. Stormwater control measures (SCM), such as stream restoration, are considered to be a subset of green infrastructure as a method to reconnect streams with surrounding riparian areas, revitalize original hydrology, and support the local ecosystems. This paper looks into the viability of stream restoration as a way of improving water quality, focusing …

Cost Benefit Analysis And Beyond: Stream Restoration In Richmond, Virginia, Claire Powell

Environmental Studies Senior Seminar Projects

This research assessed the costs and benefits of six recent stream restoration projects in Richmond, Virginia within the context of the Chesapeake Bay Total Maximum Daily Load (CB TMDL) pollutant reduction requirements. In order to meet these requirements, state and local governments promoted stream restoration as an important way to reduce Bay-wide inputs of nitrogen, phosphorus, and total suspended solids. The overall intention of this paper was to holistically evaluate the risks and positive impacts associated with stream restoration, with a focus on Little Westham Creek, a stream restoration project located on the University of Richmond campus. I hypothesized that …

Step Pools: Examining The Flow Resistance And Stability Of Artificial Step Pools In Comparison With Their Natural Counterparts, Quinn Kirkpatrick

Environmental Studies Senior Seminar Projects

This study looked at step pool stream studies, reports, and field data in five catchment areas. The areas of interest include the Rio Cordon catchment area in Italy, the Cascade Mountain Range in Washington, the Siuslaw National Forest in Oregon, various areas in California, the University of Richmond in Virginia, and the Arkansas River Basin in Colorado. The purpose of this study was to compare the flow resistance and stability after large flooding events of artificial and natural step pool sequences to potentially provide information to improve monitoring of newly installed step pools and the design of future step pool …

Exploring Options For Mussel Restoration, Henry Hurt

Environmental Studies Senior Seminar Projects

This paper seeks to explore the feasibility and possible procedures of restoring freshwater mussels to the Little Westham Creek (LWC) as a way to reduce excess organic pollutants such as nitrogen and phosphorus coming from upstream. To this end, the use of mussels in bioremediation and restoration procedures found in scientific literature were reviewed with the goal of creating a guideline of how such a project would be carried out at the Gambles Mill Eco- Corridor. Based on the results of past literature, water data collected by students in this seminar, and data from RES, it was estimated that a …

The Generality Of The Guga Mrci Approach In Columbus For Treating Complex Quantum Chemistry, Hans Lischka, Ron Shepard, Thomas Müller, Peter G. Szalay, Russell M. Pitzer, Adelia J. A. Aquino, Carol A. Parish, Et Al.

Chemistry Faculty Publications

The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calcu- lations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of π-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of dia- batization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully vari- ational …

A Template For Success: Celebrating The Work Of Judith Grabiner, Della Dumbaugh, Adrian Rice

Department of Math & Statistics Faculty Publications

Judith Grabiner is a mathematician who specializes in the history of mathematics. She is currently the Flora Sanborn Pitzer Professor Emerita of Mathematics at Pitzer College, one of the Claremont Colleges in Claremont, California. She has authored more than forty articles, as well as three books: The Origins of Cauchy’s Rigorous Calculus (1981), The Calculus as Algebra: J.-L. Lagrange, 1736–1813 (1990), and A Historian Looks Back: The Calculus as Algebra and Selected Writings (2010), which won the Beckenbach Prize from the Mathematical Association of America in 2014. She deliv- ered an invited address titled “The Centrality of Mathemat- ics in …

On Quasilinear Parabolic Equations And Continuous Maximal Regularity, Jeremy Lecrone, Gieri Simonett

Department of Math & Statistics Faculty Publications

We consider a class of abstract quasilinear parabolic problems with lower–order terms exhibiting a prescribed singular structure. We prove well–posedness and Lipschitz continuity of associated semiflows. Moreover, we investigate global existence of solutions and we extend the generalized principle of linearized stability to settings with initial values in critical spaces. These general results are applied to the surface diffusion flow in various settings.

Aromatic Ouroboroi: Heterocycles Involving A Sigma-Donor-Acceptor Bond And 4n+2 Pi-Electrons, Kelling J. Donald, William Tiznado, Rodrigo Baez-Grez, Diego Inostroza

Chemistry Faculty Publications

The aromaticity and dynamics of a set of recently proposed neutral 5- and 6-membered heterocycles that are closed by dative (donor–acceptor) or multi-center s bonds, and have resonance forms with a Hu¨ckel number of p-electrons, are examined. The donors and acceptors in the rings include N, O, and F, and B, Be, and Mg, respectively. The planar geometry of the rings, coupled with evidence from different measures of aromaticity, namely the NICSzz, and NICSpzz components of the conventional nucleus independent chemical shifts (NICS), and ring current strengths (RCS), indicate non-trivial degrees of aromaticity in certain cases, including the cyclic C3B2OH6 …

One-Pot Silyl Ketene Imine Formation-Nucleophilic Addition Reactions Of Acetonitrile With Acetals And Nitrones, C. Wade Downey, Grace Ann L. Robertson, Jhonmattew Santa, Kari R. Flicker, William M. Stith

Chemistry Faculty Publications

Trimethylsilyl trifluoromethanesulfonate (TMSOTf) and a trialkylamine base promote the conversion of acetonitrile to its silyl ketene imine in situ when acetonitrile is employed as solvent. Residual TMSOTf acts as a Lewis acid catalyst to activate acetals and nitrones in the reaction mixture, yielding β-methoxynitriles and β-(silyloxy)aminonitriles, respectively. Some reaction products undergo elimination under the reaction conditions to provide the α,β-unsaturated nitrile directly.

Score Following With Hidden Tempo Using A Switching State-Space Model, Yucong Jiang, Chris Raphael

Department of Math & Statistics Faculty Publications

A score-following program traces the notes in a musical score during a performance. This capability is essential to many meaningful applications that synchronize audio with a score in an on-line fashion. Existing algorithms often stumble on certain difficult cases, one of which is piano music. This paper presents a new method to tackle such cases. The method treats tempo as a variable rather than a constant (with constraints), allowing the program to adapt to live performance variations. This is first expressed by a Kalman filter model at the note level, and then by an almost equivalent switching state-space model at …

Spider's Guide To Sustainable Living, Office For Sustainability

Guides

Thank you for checking out this guide to caring for our future and ourselves. We're glad you did, because we need you. From the climate emergency to emerging health crises to social unrest, the need for change is all around us. The UR Sustainability Plan envisions "a future where sustainability is woven into the fabric of the University" in which we cultivate a culture of caring for people and the natural world. Consider this your invitation to join the movement to make this vision a reality.

Throughout the Spiders Guide to Sustainable Living, we will point out actions you can …

Assessing Inequitable Urban Heat Islands And Air Pollution Disparities With Low-Cost Sensors In Richmond, Virginia, Andre M. Eanes, Todd R. Lookingbill, Jeremy S. Hoffman, Kelly C. Saverino, Stephen S. Fong

Geography and the Environment Faculty Publications

Air pollution and the urban heat island effect are consistently linked to numerous respiratory and heat-related illnesses. Additionally, these stressors disproportionately impact low-income and historically marginalized communities due to their proximity to emissions sources, lack of access to green space, and exposure to other adverse environmental conditions. Here, we use relatively low-cost stationary sensors to analyze PM_2.5 and temperature data throughout the city of Richmond, Virginia, on the ten hottest days of 2019. For both hourly means within the ten hottest days of 2019 and daily means for the entire record for the year, the temperature was found to …

Landscapes Of War Permanently Altered Topography Is One Of The Casualties Of War, But Battlefields Can Also Be Of "Collateral Value", Todd R. Lookingbill, Peter D. Smallwood

Geography and the Environment Faculty Publications

But the rationale for creating battlefield parks has changed over the past 100 years, as have attitudes about battlefield conservation with a related emphasis on the physical landscapes themselves, leading to their management for multiple, layered assets through principles of constructive conservation. Existing battlefield parks provide perhaps the longest-standing examples of the evolution of landscapes of war toward generators of multiple ecosystem benefits. Moving from battlefield parks that, in some cases, have not seen warfare for hundreds of years, we examined landscapes of more recent conflict and considered the future collateral values that could be attained by establishing parks at …

Identifying Important Parameters In The Inflammatory Process With A Mathematical Model Of Immune Cell Influx And Macrophage Polarization, Marcella Torres, Jing Wang, Paul J. Yannie, Shobha Ghosh, Rebecca A. Segal, Angela M. Reynolds

Department of Math & Statistics Faculty Publications

In an inflammatory setting, macrophages can be polarized to an inflammatory M1 phenotype or to an anti-inflammatory M2 phenotype, as well as existing on a spectrum between these two extremes. Dysfunction of this phenotypic switch can result in a population imbalance that leads to chronic wounds or disease due to unresolved inflammation. Therapeutic interventions that target macrophages have therefore been proposed and implemented in diseases that feature chronic inflammation such as diabetes mellitus and atherosclerosis. We have developed a model for the sequential influx of immune cells in the peritoneal cavity in response to a bacterial stimulus that includes macrophage …

Adaptable Xerogel-Layered Amperometric Biosensor Platforms On Wire Electrodes For Clinically Relevant Measurements, Lillian B. Hughes, Najwa Labban, Grace E. Conway, Julie A. Pollock, Michael C. Leopold

Chemistry Faculty Publications

Biosensing strategies that employ readily adaptable materials for different analytes, can be miniaturized into needle electrode form, and function in bodily fluids represent a significant step toward the development of clinically relevant in vitro and in vivo sensors. In this work, a general scheme for 1st generation amperometric biosensors involving layer-by-layer electrode modification with enzyme-doped xerogels, electrochemically-deposited polymer, and polyurethane semi-permeable membranes is shown to achieve these goals. With minor modifications to these materials, sensors representing potential point-of-care medical tools are demonstrated to be sensitive and selective for a number of conditions. The potential for bedside measurements or continuous monitoring …

The Price Is Right: Analyzing Bidding Behavior On Contestants’ Row, Paul Kvam

Department of Math & Statistics Faculty Publications

The TV game show “The Price is Right” features a bidding auction called Contestant’s Row that rewards the player (out of four) who bids closest to an item’s value without overbidding. By exploring 903 game outcomes from the 2000–2001 season, we show how player strategies are significantly inefficient, and compare the empirical results to probability outcomes for optimal bid strategies found in a recent study. Findings show that the last bidder would do better using the naïve strategy of bidding a dollar more than the highest of the three bids. We apply the EM algorithm in a novel way to …

Luminosity-Luminosity Correlations In Flux-Limited Multiwavelength Data, J. Singal, V. Petrosian, J. Haider, S. Malik

Physics Faculty Publications

We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with …

Hydropower As A Feasible Option Of The University Of Richmond, Gershom Ejoni

Environmental Studies Senior Seminar Projects

As the University of Richmond moves forward in achieving its sustainability goals, it made a decision to invest into a solar array in Spotsylvania, VA in order to offset their energy consumption with renewable energy. However, this solar array has been controversial for many of the residents in Spotsylvania. My senior seminar class has tasked itself with investigating all aspects of the University’s decision to partner with sPower. This paper will analyze the potential alternative energy sources that the University can possible consider, in particular, hydropower; thereby, determining if hydropower is a potential viable option the University of Richmond can …

The Most Environmentally Beneficial Option: An Analysis On Spower’S Solar Project In Relation To The Endangered Species Act, Victoria Williams

Environmental Studies Senior Seminar Projects

Today, the current impacts of high greenhouse gas emissions due to energy production have been widely discussed in scholarly literature. In 2018, the University of Richmond (UR) announced a goal to match 100% of the campus' electricity demand with solar energy to decrease its carbon footprint. UR partnered with sPower to construct a 500-megawatt solar array in which UR will receive the 20-megawatts worth of energy from the site in Spotsylvania, Virginia. sPower’s solar project engendered various environmental concerns surrounding Fawn Lake and the endangered species found in the proximity of the project. Acknowledging the environmental concerns, the objective of …

Spotsylvania Solar Farm: Watershed Environmental Analysis: Material And Chemical Impacts, Colby Prokop

Environmental Studies Senior Seminar Projects

The purpose of this compiled review is to answer the research question: What are the implications of the materials being used in the Spotsylvania sPower solar farm and the impacts of any contributing chemicals? I will approach this question using a theoretical framework to investigate the public participation (PP) process (Munch-Petersen, 2017) in the preliminary environmental analysis research done by sPower (in accordance with their special use permit [SUP]). This will be a context-specific framework, in which I will navigate the discrepancies between the environmental SUP information and citizen concerns about the chemicals and materials used in the sPower solar …

Analyzing Nuclear Power And Its Present And Future Role As A Low Carbon Emissions Energy Source, Maria Seitz

Environmental Studies Senior Seminar Projects

This report takes look at nuclear power and its current use around the world and its potential as a key player in the current global climate crisis. Through the analysis of surveys, articles, and research papers, this essay explores how nuclear power plants compare to other low emission energies and how their use can lead to global reductions in carbon emissions. It examines the pros and cons of nuclear and its ultimate role in helping to reduce global carbon emissions.

Paper prepared for the Environmental Studies Senior Seminar.

Faculty Advisor: Dr. David Kitchen

Is Wind Energy A Better Option For The University Of Richmond?, Steven Yu

Environmental Studies Senior Seminar Projects

The purpose of this assignment is to answer the question of: Is Wind Energy the Better Option for the University of Richmond? This question is more than simply if wind power will supply the campus the greatest amount of energy, but also looks at the educational, social, environmental and political benefits that would also be associated with it. In order to understand the feasibility of wind power on the University of Richmond campus, I looked at factors such as: energy production from wind turbines, past wind patterns in Richmond, VA, impacts to the environment. This is only one part of …