Background: Due to the rising popularity of autonomous unmanned vehicles, and the lack of well-defined rules to follow, a solution is needed when the physical space is crowded to a point where it becomes a hazard. Partitioning space discretely is currently done in some cases, allowing vehicles to reserve partitions to operate within. This idea is expanded upon to ultimately propose a blockchain-based solution to the inefficiency of safety margins. Objectives: The main objective was to explore whether a blockchain-based system can be used by vehicles to automatically reserve the volumes of space they need for a limited time. The solution to congestion becomes a method for vehicles to communicate between each other to exchange the remainder of their reservations once they are no longer needed, even while disconnected from the main blockchain network, in exchange for the same currency used to reserve the volumes. Methods: An Ethereum private blockchain network is set up, and a smart contract is developed and deployed onto this blockchain. An emulation program used the smart contract functions to reserve and exchange volumes to evaluate the functionality, several isolated tests evaluated the network performance, and aspects that could not be tested were theoretically analyzed. Results: The system functions as intended, although a level of trust is required during exchanges. There is no risk of two vehicles reserving the same volume at the same time. The results indicate that some performance aspects will be affected by an increasing number of users, although the entire effect can be placed on synchronization time if the network parameters are adjusted. This likely affects the overall efficiency but not as much as it would with the original parameters. Conclusions: The proposed solution is viable to use, although further development is necessary before it is ready for release. The necessity currently is not evident, although projections suggest that this solution, or a similar one, will be necessary in the future.

Starting in the early 2000s, a number of U.S. communities have adopted "zero waste" commitments to reduce waste as much as possible through recycling, composting, and other means. Little in-depth information exists about the impetus for or efficacy of these efforts. The author sought to build knowledge on the topic by conducting case studies of two communities: the zero waste efforts of Boulder, Colorado, and the Zero Waste Zones established in Atlanta. The two cases presented an interesting contrast, in terms of sector driving zero waste: public in Boulder, and private in Atlanta. The study aimed to use the experiences of these two communities, supplemented with background research on materials management and application of relevant theory, to develop a set of considerations for more informed pursuit of zero waste. The author gathered qualitative data by conducting unstructured interviews of the actors involved with the zero waste efforts in Boulder and Atlanta. Interview questions concerned, e.g., zero waste goals and plans, the impacts of zero waste on the business or organization, and influential individuals or organizations. The study produced the following set of considerations: Definition of waste determines priorities and impacts of zero waste efforts; responsibility for waste arbitrarily resides with consumers and local government instead of producers; the private, public, and nonprofit sectors each play important roles in waste reduction; local government should not bear the full burden of materials management; and state and federal government can offer useful policy tools to advance zero waste. / Master of Urban and Regional Planning

abstract: Zero-Valent Metals (ZVM) are highly reactive materials and have been proved to be effective in contaminant reduction in soils and groundwater remediation. In fact, zero-Valent Iron (ZVI) has proven to be very effective in removing, particularly chlorinated organics, heavy metals, and odorous sulfides. Addition of ZVI has also been proved in enhancing the methane gas generation in anaerobic digestion of activated sludge. However, no studies have been conducted regarding the effect of ZVM stimulation to Municipal Solid Waste (MSW) degradation. Therefore, a collaborative study was developed to manipulate microbial activity in the landfill bioreactors to favor methane production by adding ZVMs. This study focuses on evaluating the effects of added ZVM on the leachate generated from replicated lab scale landfill bioreactors. The specific objective was to investigate the effects of ZVMs addition on the organic and inorganic pollutants in leachate. The hypothesis here evaluated was that adding ZVM including ZVI and Zero Valent Manganese (ZVMn) will enhance the removal rates of the organic pollutants present in the leachate, likely by a putative higher rate of microbial metabolism. Test with six (4.23 gallons) bioreactors assembled with MSW collected from the Salt River Landfill and Southwest Regional Landfill showed that under 5 grams /liter of ZVI and 0.625 grams/liter of ZVMn additions, no significant difference was observed in the pH and temperature data of the leachate generated from these reactors. The conductivity data suggested the steady rise across all reactors over the period of time. The removal efficiency of sCOD was highest (27.112 mg/lit/day) for the reactors added with ZVMn at the end of 150 days for bottom layer, however the removal rate was highest (16.955 mg/lit/day) for ZVI after the end of 150 days of the middle layer. Similar trends in the results was observed in TC analysis. HPLC study indicated the dominance of the concentration of heptanoate and isovalerate were leachate generated from the bottom layer across all reactors. Heptanoate continued to dominate in the ZVMn added leachate even after middle layer injection. IC analysis concluded the chloride was dominant in the leachate generated from all the reactors and there was a steady increase in the chloride content over the period of time. Along with chloride, fluoride, bromide, nitrate, nitrite, phosphate and sulfate were also detected in considerable concentrations. In the summary, the addition of the zero valent metals has proved to be efficient in removal of the organics present in the leachate. / Dissertation/Thesis / Masters Thesis Environmental and Resource Management 2019

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第18407号 / 情博第522号 / 新制||情||92(附属図書館) / 31265 / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 黒橋 禎夫, 教授 西田 豊明, 教授 河原 達也 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

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The goal of this case study was to investigate the behavior of real textile wastewater in DCMD (Direct Contact Membrane Distillation) treatment and subsequently to develop a simple and effective pretreatment for it. To this moment, this work is one of the only studies to make an in-depth analysis of the treatment while considering the complexity of this effluent, which is inherently composed of Volatile Organic Compounds (VOCs) and surfactants. After the application of pretreatment, it became clear that the main concern with textile wastewater treatment using MD is wetting, not fouling. Sedimentation and filtration alone were effective in removing suspended solids, but insufficient in stopping wetting. However, neutralization before sedimentation and filtration was proven to be a fundamental step in reducing wetting rates. This improved performance happens due to the change in pH of the wastewater sample, which increases the rejection rates by the membrane. The best experiments, neutralized to pHs 7.40 and 9.06, achieved up to 99.89% rejection by the membrane, with up to 97% conductivity decrease when compared to an experiment without neutralization, 97% removal of COD, and 98% TOC. Overall, the permeate obtained in this work after pretreatment demonstrated excellent quality, and the recovered effluent can possibly be reused in the textile industry, aiming for Zero Liquid Discharge (ZLD) processes. Thus, scaling up this technology for real industrial use is still necessary, tailoring the treatment to the effluent's characteristics to obtain the best results.

For a graph G we define S(G) to be the set of all real symmetric n by n matrices whose off-diagonal zero/nonzero pattern is described by G. We show how to compute the minimum rank of all matrices in S(G) for a class of graphs called outerplanar graphs. In addition, we obtain results on the possible eigenvalues and possible inertias of matrices in S(G) for certain classes of graph G. We also obtain results concerning the relationship between two graph parameters, the zero forcing number and the path cover number, related to the minimum rank problem.