Anomalous dynamics of Darcy flow and diffusion through heterogeneous media

This thesis studies diffusion phenomena in heterogeneous media, which includes Darcy flow and diffusive solute transport in geological media. Natural media are heterogeneous at different scales, which induces complexity in diffusion phenomena. The work is centered on the integration of the effects of heterogeneity on Darcy flow and solute diffusion into large scale models. The quantification of the effects of heterogeneity in diffusion phenomena is highly important for a large number of problems such as diffusion and reaction of chemicals and radionuclides in low permeability media, which is essential in subsurface hazardous waste storage problems, CO2 sequestration performance and groundwater management. In a stochastic framework we quantify the effects of heterogeneity in large scale models considering two interrelated strategies that can be called Ôcoefficient approachÕ, which deals with the derivation of effective coefficients to insert in equivalent homogeneous models, and Ôdynamic approachÕ, which deals with the upscaling of the local scale equations and the derivation of large scale formulations which can differ from their local counterparts. Whenever a diffusion process cannot be described in terms of effective coefficient, that behaviour is named anomalous or non-Fickian. Anomalous diffusion behaviours observed experimentally are frequently modelled by effective theories such as fractional diffusion equations, continuous time random walks. One limitation of these models is that often they are rather phenomenological and the relation to the local scale heterogeneity and dynamics may not be clear. In the dynamic approach we derive large scale descriptions that can explain anomalous behaviour and link it with a description of the local scale medium heterogeneity. To this end, we upscale the local scale governing equations using different methods depending on the type of medium heterogeneity. For moderately heterogeneous media we upscale flow equation by stochastic averaging. Starting from the classical flow equation at local scale determined by Darcy's law, we derive an upscaled non-local effective formulation. The non-local effective formulation is compared with its local counterpart by considering the head response for a pulse injection. Numerically, we solve flow and diffusion in heterogeneous media using particle tracking methods. While classical random walk particle tracking is an efficient numerical tool to solve for diffusion problems in moderately heterogeneous media, strong medium contrasts, as encountered in fractured media, render this method inefficient. For highly heterogeneous media efficiency of classical random walk can be increased by the use of the time domain random walk (TDRW) method. We rigorously derive the equivalence of the TDRW algorithm and the diffusion equation and we extend the classical TDRW method to solve diffusion problem in a heterogeneous medium with multi-rate mass transfer properties. Moreover we use the TDRW method in connection with a stochastic model for the heterogeneity in order to upscale heterogeneous diffusion processes. For a certain class of heterogeneity, the upscaled dynamics obey a CTRW. Analytically we upscale diffusion in highly heterogeneous media by using a multicontinuum representation of the media. Using volume and ensemble averaging we derive a multicontinuum model that can explain anomalous diffusion behavior and link it with a suitable local scale description of the medium heterogeneity. Finally, we integrate the multicontinuum model derived in the context of aquifer modelling. We derive a multicontinuum catchment model that can explain anomalous behavior observed in the aquifer dynamics at basin scale. We identify the physical mechanisms that induce anomalous behaviour and we determine the time scales that control its temporal evolution

Protecting Passenger Fees: Reawakening Congress’s Tonnage Clause Authorization Powers

For 20 years, the City of Juneau has collected passenger fees from cruise lines that enter its port. These fees are assessed based on the number of passengers that arrive on each cruise vessel, and amount to $8.00 per passenger. On December 6, 2018, in Cruise Lines International Association Alaska v. The City and Borough of Juneau , the U.S. District Court of Alaska held that Juneau’s use of the passenger fees violates the U.S. Constitution’s Tonnage Clause. Rather than appeal the decision, the City of Juneau subsequently settled the litigation with the cruise lines. This Note will examine Juneau’s passenger fees in light of the Tonnage Clause. It will argue that because Juneau and the State of Alaska depend on these fees and other tourism revenue, Alaska policymakers should lobby Congress to use its Tonnage Clause authorizing powers to grant Alaska port cities the authority to charge set passenger fees to visiting cruise lines. Part One will analyze the Court’s historical understanding of the Tonnage Clause. Part Two will examine the litigation, the court’s decision in Cruise Lines International, and the recent settlement between the City and the cruise lines. Part Three will consider how this case may disrupt Alaska’s tourism industry and economy and will focus on other Alaska laws that may be invalidated on the basis of this decision. Part Four will propose a model law for passage by Congress, to help Alaska work around the holding in Cruise Lines International

A Return to the Region: Reconstructing the Past in Jewett, Cather, and Hurston (1896-1935)

My senior project focuses on three works of American literature, starting from 1896 and ending in 1935. During this time period, the United States was undergoing drastic cultural and industrial changes, both of which indefinitely reshaped the American landscape. My project seeks to understand these changes through Sarah Orne Jewett’s The Country of the Pointed Firs (1896), Willa Cather’s My Ántonia (1918), and Zora Neale Hurston’s Mules and Men (1935). All three works look beyond the city, and instead look inward toward small regional communities in Maine, Nebraska, and Florida. With the regional focus placed on the narratives, my project stands as a way to explore the intersection of landscape, nostalgia, and preservation– while each protagonist tells a separate narrative on the complexity and triumphs of being an outsider

A Holistic Analysis of Energy Storage Systems Applied to Single-Family Residences in California

The technology this paper focuses on is energy storage systems applied to single-family residences in California. This relatively new technology consists of a stationary battery that is connected to a power source, most notably photovoltaic panels on the roof. The holistic nature of this research paper is meant to incorporate the principle aspects surrounding the current state and affordability of these systems such as the type of batteries used, government incentives, the predominant benefits, and emerging trends that will dictate the future of these systems. The information was gathered by conducting an extensive literature review and interviewing ten energy storage experts which provided contemporary information that was not found in databases. The most popular batteries were the LG Chem RESU 10H and the Tesla Powerwall. The main factors that increased affordability was the Federal Investment Tax Credit, Self-Generation Incentive Program, and the reduction of on-peak electricity prices from investor owned utilities. Aside from the return on investment, homeowners can achieve peace of mind from having backup power to withstand power outages, as well as reduce carbon emissions by increasing photovoltaic capabilities. Lastly, emerging trends such as NEM 3.0 and vehicle-to-home will likely shape the future of energy storage

The Implications of Nesting in California Redistricting

Evaluates the process of nesting -- aggregating or dividing assembly and senate districts -- on redistricting outcomes, including compactness, minimizing city and county divisions, and the creation of majority minority seats

Case Note: Russian Federation

Case No. А40-19739/08-10-141, Arbitrazh Court of Moscow. Date of decision: 25 June 2008. Note by Alex Dolzhich

A Narrative Summary of High Flow Nasal Cannula Therapy in the Adult Population

Purpose: The aim of this narrative review is to outline the mechanism of action of HFNC therapy, the clinical benefits of its use, cautions of its clinical application and limitations of previous research. Methods: A literature review was conducted using the following databases as sources: Medline, PubMed, and Google Scholar. Only publications written in English were used in this clinical review. Keywords used in the search included the following: high-flow nasal cannula, heated humidified oxygen, oxygen therapy, non-invasive ventilation, and respiratory failure. Results: The literature reveals HFNC therapy significantly decreased the use of mechanical ventilation (invasive or non-invasive) in patients experiencing respiratory failure. HFNC therapy was better tolerated by patients and decreased the patient’s work of breathing when compared to a conventional oxygen therapy (i.e., non-rebreather oxygen mask). Other clinical benefits of using HFNC when changing a patient from conventional facemask oxygen therapy to a HFNC device are significant improvements in PaO2, respiratory rate and overall comfort. Conclusions: High flow nasal cannula (HFNC) therapy serves as an alternative to conventional oxygen therapy to deliver elevated concentrations of oxygen to patients experiencing acute respiratory failure. Information detailed in this article suggests HFNC therapy is an effective therapy for improving a patient’s oxygenation status when experiencing acute respiratory failure in adults. The literature reveals, it is reasonable to initiate HFNC in adults with acute hypoxemic respiratory failure without hypercapnia, as an alternative to standard oxygen therapy or noninvasive positive pressure ventilation