Virginia's regional grain prices exhibit high volatility due to the state's unique spatial variability and supply and demand fundamentals. This study explains Virginia's basis patterns for corn, soybeans, and wheat. Discussion of times when there were outstanding economic or fundamental market movers that affected basis in Virginia is also offered. The feasibility and process of hedging using futures is explained and evaluated in a case study. Possible marketing decisions based on the findings are presented in an easy and accessible manner, so that producers and extension agents can use this information to make real-time grain marketing decisions. / Master of Science / Virginia's regional grain prices exhibit high volatility due to the state's unique spatial variability and supply and demand fundamentals. This study explains Virginia's basis patterns for corn, soybeans, and wheat. Discussion of times when there were outstanding economic or fundamental market movers that affected basis in Virginia is also offered. The feasibility and process of hedging using futures is explained and evaluated in a case study. Possible marketing decisions based on the findings are presented in an easy and accessible manner, so that producers and extension agents can use this information to make real-time grain marketing decisions.

The fundamental advantages of applying Isogeometric Analysis (IGA) to shell analysis have been extensively demonstrated across a wide range of problems and formulations. However, a phenomenon called numerical locking is still a major challenge in IGA shell analysis, which can lead to dramatically deteriorated analysis accuracy. Additionally, for complex thin-walled structures, a simple and robust coupling technique is desired to sew together models composed of multiple patches. This dissertation focuses on addressing these challenges of IGA shell analysis. First, an isogeometric dual mortar method is developed for multi-patch coupling. This method is based on Be ?zier extraction and projection and can be employed during the creation and editing of geometry through properly modified extraction operators. It is applicable to any spline space which has a representation in Be ?zier form. The error in the method can be adaptively controlled, in some cases recovering optimal higher-order rates of convergence, by leveraging the exact refineability of the proposed dual spline basis without introducing any additional degrees-of-freedom into the linear system. This method can be used not only for shell elements but also for heat transfer and solid elements, etc. Next, a mixed formulation for IGA shell analysis is proposed that addresses both shear and membrane locking and improves the quality of computed stresses. The starting point of the formulation is the modified Hellinger-Reissner variational principle with independent displacement, membrane, and shear strains as the unknown fields. To overcome locking, the strain variables are interpolated with lower-order spline bases while the variations of the strain variables are interpolated with the proposed dual spline bases. As a result, the strain variables can be condensed out of the system with only a slight increase in the bandwidth of the resulting linear system and the condensed approach preserves the accuracy of the non-condensed mixed approach but with fewer degrees-of-freedom. Finally, as an alternative, new quadrature rules are developed to release membrane and shear locking. These quadrature rules asymptotically only require one point for Reissner-Mindlin (RM) shell elements and two points for Kirchhoff-Love (KL) shell elements in B-spline and NURBS-based isogeometric shell analysis, independent of the polynomial order p of the elements. The quadrature points are Greville abscissae and the quadrature weights are calculated by solving a linear moment fitting problem in each parametric direction. These quadrature rules are free of spurious zero-energy modes and any spurious finite-energy modes in membrane stiffness can be easily stabilized by using a higher-order Greville rule.

Per- and polyfluoroalkyl substances (PFAS) are known for their persistence as well as their hydrophobic and lipophobic nature. Widespread use has led to increasing prevalence of PFAS in the environment. Due to PFAS:s extensive spread and adverse health effects, remediation of PFAS-contaminated areas has increased in recent years, resulting in an increased demand for disposal of contaminated soil. To dispose waste at landfills in Sweden, certain criteria need to be met. However, for PFAS there are no specific guidelines and landfills therefore decide their own acceptance criteria. This can lead to varying requirements, potentially causing environmentally hazardous practices. The aim of this study was to survey the requirements applied by landfills, as well as investigate how different assessment bases affect the evaluation of PFAS-contaminated soil. The study was conducted both as a questionnaire sent to 80 landfills in Sweden, and as an analysis of test results from samples of PFAS- contaminated soil. The findings reveal varying information requirements, with common criteria including soil origin, presence of contaminants and analysis of PFAS when soil is suspected of contamination. Landfills also typically required documentation about the contaminated site, sampling plan and leachate tests when accepting PFAS-contaminated soil. Additionally, this study demonstrates that the evaluation of PFAS-contaminated soil can depend on the assessment basis used. The assessment based on toxic equivalents, may alter the risk valuation in comparison to those based on measured concentrations. To include commonly occurring PFAS, the analysis should include a minimum of PFAS11.

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The synthetic utility of nitrile-stabilized carbanions as reactive intermediates for selective carbon-carbon bond formation has prompted numerous studies toward characterization of the solution structure of these nucleophiles. In hopes of eventually gaining a better understanding of the structural properties which may mediate reactivity and selectivity, researchers have designed elegant structure elucidation strategies. These studies have offered key advancements toward the characterization of these intermediates; however, contradictory evidence has hindered unambiguous structural determination—particularly for lithiated benzylic nitriles in low dielectric, ethereal media. Chapter 1 of this dissertation presents a review of the synthetic utility of metalated nitriles and the spectroscopic and computational techniques employed to characterize their solution structure. Also reviewed herein are the controversial determinations drawn from these efforts. The research and data which follow in Chapters 2 and 3 focus on resolution of the conflicting structural determinations drawn from multinuclear magnetic resonance (NMR) and vibrational (IR and Raman) spectroscopy. Employing a strategy to slow the lithium-nitrogen exchange rate in low dielectric media, new 7Li, 31P, and 15N NMR spectroscopic evidence (with support from computational modeling) lead us to amend our previous assessments and propose that lithiated arylacetonitriles adopt an aggregated triple-ion structure in THF/hexane with sub-stoichiometric HMPA. Due to the limitations of computer resources and the effect of non-linear scaling, theoretical modeling of aggregated and solvated lithiated benzylic nitriles became impractical at the 6-31+G(d) basis set. These limitations led to the use and comparative analysis of two alternative basis sets for the DFT analysis of lithiated benzylic nitrile derivatives' 6-31(+LiX)G(d) and 6-31â +â G(d). Defined upon the principal of resonance stabilization, these basis sets were constructed by application of varying levels of computational theory on a per-atom basis. By applying higher levels of theory only to the atoms most intimately involved in the electronic distribution, "accurate" replacement models for 6-31+G(d) structures were obtained with considerable savings in computational resources. This study in basis set economy is detailed fully within Chapters 4 and 5. / Ph. D.