A form of the Euler equations preserving potential flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77316/1/AIAA-1999-3280-269.pd

An Introduction to Consumptive Use of Water in South Carolina

Effective water resource management requires understanding the supply of and the demand for water. In South Carolina, as in other places, water demand is often determined using total withdrawal volumes. However, the volume of water that is withdrawn can be significantly different from the volume that is actually consumed, which becomes unavailable for downstream uses. Water used for energy generation is commonly excluded from evaluations of total withdrawal volume because it is often assumed to be no or low consumptive use, meaning much of the withdrawn water is returned to the source and remains available for downstream uses. Additionally, energy production withdrawal volumes may be significantly higher than other sectors’ usage and make it difficult to further compare water use of other sectors. Consumptive use volumes are not readily available for South Carolina and can be challenging to determine. However, estimates of consumptive use could allow more meaningful comparisons between water use sectors’ impacts. The objective of this short communication is to briefly discuss data sources, outline two relatively simple methods for calculating consumptive use with available data, identify challenges and opportunities for additional research, and provide preliminary estimates of consumptive water use volumes per water use sectors in South Carolina. Expanded discussion of consumptive water use of thermoelectric energy generation is included due to the significant total water withdrawals and unique challenges with calculating consumptive use of this sector. These results inform water resource planning and identify additional research opportunities

A third-order fluctuation splitting scheme that preserves potential flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76630/1/AIAA-2001-2595-100.pd

Three essays on the economics of water management in agriculture

This dissertation presents three essays on the economics of water management in agriculture. The overarching objective of the dissertation is to explore the effects of institutional setting and biophysical complexity on individual decisions around water use as an input. The focus of the dissertation is on agricultural systems that use groundwater as a source of irrigation. The first essay is an empirical study of the role of trading ratios and search frictions in a groundwater market with spatial externalities. Econometric results suggest that the use of trading ratios can indeed provide incentives for market participants to reallocate resources in a way that reduces spatial externalities. In the localized informal market I study, search frictions can be significant, with estimated loss of efficiency of up to 40%. In the second essay, I develop an analytical framework to explore policy implications of limitations imposed on groundwater flow rates by underlying aquifer characteristics. I find that limitations on the instantaneous supply of groundwater can affect irrigation decisions nonlinearly with a threshold effect. A profit-maximizing farmer with maximum available water flow rate below the threshold adjusts irrigation decisions on both the extensive (inter-seasonal) and intensive (intra-seasonal) margins. Above the threshold, optimally only intensive margin adjustment occurs. I further explore the role of heterogeneity in aquifer characteristics on the effectiveness of different aquifer management policies for Chase County, Nebraska, using a numerical model. I find that under conditions of heterogenous instantaneous water availability, the burden of different policies may fall on different groups of water users in ways that have not been previously described. This result suggests that policy makers may need to consider the distributional effects of water management policies as well as their cost effectiveness. Finally, in the third essay, I analyze the effects of groundwater depletion on the loss of buffer value of an aquifer. The chapter develops a framework that captures nonlinearities in the effect of aquifer levels on the instantaneous supply of groundwater as well as the intra-seasonal nature of irrigation decisions. Applying the methodology to a portion of the High Plains Aquifer, I find that the costs of aquifer depletion may be greater than previously considered. Specifically, I show that loss of profit due to the inability to use groundwater to buffer against intra-seasonal variations of weather can be an order of magnitude higher than the loss of profit due to increased pumping costs. I also find that changes in aquifer levels have had quite different effects on buffer values across the area considered. The results suggest that while, on average, benefits to aquifer management in a given area may be small, there may be localized regions with large benefits

Stakeholder Voice in Water Resource Planning

Stakeholder engagement for natural resource management at the state and local levels has become an important governance practice. This study examines the association of individual traits (aggressive communication, comfort with technology, and argumentativeness) with stakeholder participant voice in a water basin planning virtual meeting setting. Individual participants of the Edisto River Basin Council (RBC) meetings are the subject of the study. South Carolina decentralized water planning to the river basin level, creating RBCs and appointing interested and relevant stakeholders as members. While the river basin planning process did not envisage virtual (Zoom) meetings for the regular meetings of the RBC, the COVID pandemic required this to begin the planning process. Moreover, meeting participants possess diverse interests, powers, and individual traits that may affect the use of voice and engagement. There is well-established literature on stakeholder participation in resource planning. However, there are gaps in the literature regarding use of voice in virtual meeting settings in water resources planning, especially in settings like water-abundant areas in the Southeastern United States. Using the Edisto RBC as a pilot basin and quantitative surveys, preliminary results found that while RBC participants were on average comfortable with technology, they generally avoided conflict, they exhibited average communication apprehension in a meeting environment, and virtual meetings appear to limit participant’s use of voice. Consequently, meeting planners must recognize that not all participants express themselves optimally in virtual meeting settings. In this vein, planners must work to develop opportunities for as much active engagement and sharing as possible

Eulerian ISPH Method for Simulating Internal Flows

In this article the possibility to use Eulerian approach in the conventional ISPH method in simulation of internal fluid flows is studied. The use of Eulerian approach makes it possible to use non-uniform particle distributions to increase the resolution in the sensitive parts of the domain, different boundary conditions can be employed more freely and particle penetration in the solid walls and tensile instability no longer require elaborate procedures. The governing equations are solved in an Eulerian framework containing both the temporal and local derivatives which make the momentum equations non-linear. Some special treatment and smaller time steps are required to remedy this non-linearity of the problem. In this study, projection method is used to enforce incompressibility with the evaluation of an intermediate velocity and then this velocity is projected on the divergence-free space. This method is applied to the internal fluid flows in a shear-driven cavity, Couette flow, a flow inside a duct with variable area and flow around a circular cylinder within a constant area duct. The results are compared with the results of Lagrangian ISPH and WCSPH methods as well as finite volume and Lattice Boltzmann grid based schemes. The results of the studied scheme have the same accuracy for velocity field and have better accuracy in pressure distribution than ISPH and WCSPH methods. Non-uniform particle distributions are also studied to check the applicability of this method and Good agreement is also observed between uniform and non-uniform particle distributions

Impact of spatially correlated pore-scale heterogeneity on drying porous media

We study the effect of spatially-correlated heterogeneity on isothermal drying of porous media. We combine a minimal pore-scale model with microfluidic experiments with the same pore geometry. Our simulated drying behavior compares favorably with experiments, considering the large sensitivity of the emergent behavior to the uncertainty associated with even small manufacturing errors. We show that increasing the correlation length in particle sizes promotes preferential drying of clusters of large pores, prolonging liquid connectivity and surface wetness and thus higher drying rates for longer periods. Our findings improve our quantitative understanding of how pore-scale heterogeneity impacts drying, which plays a role in a wide range of processes ranging from fuel cells to curing of paints and cements to global budgets of energy, water and solutes in soils

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

Peer reviewe