Application of Agent-Based Modeling to Complex Systems

This dissertation examines the application of agent-based modeling (ABM) to complex systems with the intent of developing a means of overcoming limitations present in existing tools. This is done though the development of two ABMs intended to address complex systems present in the fields of sustainability studies and chemistry. After introductory information, Chapters 2 - 4 of this dissertation address the limitations of tools intended to project the environmental, economic, and social impacts of woody biomass based biofuels. Chapter 2 begins by discussing the limitations in tools to study timber harvest decision making and its impact upon the landscape, and develops an ABM platform to address this gap. Next, Chapter 3 presents a life cycle assessment (LCA) of a proposed biorefinery in Ontonagon, Michigan is conducted. This study acts as a benchmark benchmark for the case study presented in Chapter 4, where an argument for the integration of ABM and life cycle sustainability assessment (agent-based LCSA) is presented. The argument is followed by a case study demonstrating the applicability of the technique. The case study finds that while Ontonagon is a promising site for a biorefinery, there are concerns regarding the quantity of woody biomass that may be delivered as a feedstock and potential impacts upon regional wetlands. Chapter 5 of this dissertation addresses the limitations of models of advanced oxidation processes (AOPs) using ordinary differential equations (ODEs). We argue that these limitations can be addressed by modeling the AOP as a complex system, including the complete elementary reaction pathway using ABM. To demonstrate the applicability of this novel approach, an ABM is developed and two in silico studies of acetone degradation induced by hydroxyl radicals are performed. We found that when using a comprehensive list of elementary reaction pathways, the ABM was able to replicate concentration curves for major chemical species in our laboratory study. As a novel application of ABM to AOPs we conclude that the technique shows considerable promise

Preserving academic poster content

posterPosters are an important way to share information between academia and industry. They are presented at national conferences, regional meetings, and even in university departments. There were almost 75,000 calls for poster submissions last year alone. Most posters are presented for only a few hours at a conference and may be difficult to translate into full papers. Posters are represented by abstracts submitted months before conferences. They may not accurately reflect poster content. A new method for preserving academic poster content is needed

Role of seasonal importation and genetic drift on selection for drug-resistant genotypes of Plasmodium falciparum in high-transmission settings

Historically Plasmodium falciparum has followed a pattern of drug resistance first appearing in low-transmission settings before spreading to high-transmission settings. Several features of low-transmission regions are hypothesized as explanations: higher chance of symptoms and treatment seeking, better treatment access, less within-host competition among clones and lower rates of recombination. Here, we test whether importation of drug-resistant parasites is more likely to lead to successful emergence and establishment in low-transmission or high-transmission periods of the same epidemiological setting, using a spatial, individual-based stochastic model of malaria and drug-resistance evolution calibrated for Burkina Faso. Upon controlling for the timing of importation of drug-resistant genotypes and examination of key model variables, we found that drug-resistant genotypes imported during the low-transmission season were (i) more susceptible to stochastic extinction due to the action of genetic drift, and (ii) more likely to lead to establishment of drug resistance when parasites are able to survive early stochastic loss due to drift. This implies that rare importation events are more likely to lead to establishment if they occur during a high-transmission season, but that constant importation (e.g. neighbouring countries with high levels of resistance) may produce a greater risk during low-transmission periods

An Ancient Relation between Units of Length and Volume Based on a Sphere

The modern metric system defines units of volume based on the cube. We propose that the ancient Egyptian system of measuring capacity employed a similar concept, but used the sphere instead. When considered in ancient Egyptian units, the volume of a sphere, whose circumference is one royal cubit, equals half a hekat. Using the measurements of large sets of ancient containers as a database, the article demonstrates that this formula was characteristic of Egyptian and Egyptian-related pottery vessels but not of the ceramics of Mesopotamia, which had a different system of measuring length and volume units

Does the history of food energy units suggest a solution to "Calorie confusion"?

The Calorie (kcal) of present U.S. food labels is similar to the original French definition of 1825. The original published source (now available on the internet) defined the Calorie as the quantity of heat needed to raise the temperature of 1 kg of water from 0 to 1°C. The Calorie originated in studies concerning fuel efficiency for the steam engine and had entered dictionaries by 1840. It was the only energy unit in English dictionaries available to W.O. Atwater in 1887 for his popular articles on food and tables of food composition. Therefore, the Calorie became the preferred unit of potential energy in nutrition science and dietetics, but was displaced when the joule, g-calorie and kcal were introduced. This article will explain the context in which Nicolas Clément-Desormes defined the original Calorie and the depth of his collaboration with Sadi Carnot. It will review the history of other energy units and show how the original Calorie was usurped during the period of international standardization. As a result, no form of the Calorie is recognized as an SI unit. It is untenable to continue to use the same word for different thermal units (g-calorie and kg-calorie) and to use different words for the same unit (Calorie and kcal). The only valid use of the Calorie is in common speech and public nutrition education. To avoid ongoing confusion, scientists should complete the transition to the joule and cease using kcal in any context

John Buridan, Metaphysician and Natural Philosopher. An Introductory Survey

Contains fulltext : 160641.pdf (publisher's version ) (Closed access

The Metaphysics and Natural Philosophy of John Buridan

Contains fulltext : 205228.pdf (publisher's version ) (Closed access)XVII + 300 p

Life cycle assessment of the production of gasoline and diesel from forest residues using integrated hydropyrolysis and hydroconversion

Purpose Renewable gasoline and diesel can be produced through integrated hydropyrolysis and hydroconversion (IH2 ) using renewable feedstocks such as woody biomass from logging residues. This study assesses the potential environmental impacts of IH2 process fuels manufactured in Ontonagon, Michigan, to determine their environmental impacts and if these manufactured fuels will meet Renewable Fuel Standards (RFS) requirements. The energy return on investment (EROI) is also calculated for comparison to other renewable fuels. Methods A cradle-to-grave life cycle assessment was conducted using regional forestry, timber harvest, and transportation data from the region. Regional geographic data was used to determine service areas that may provide woody biomass. The service areas were then developed into inventory data based upon the type and distribution of potential woody biomass feedstocks. Survey data from loggers in the region were used to ensure that harvest types were allocated in accordance with regional activity. Remaining inventory items were derived from existing data in the literature or existing life cycle inventory databases. This study uses a functional unit of one megajoule of gasoline or diesel produced using the IH2 process and assessed several environmental indicators as well as EROI. Results and discussion Fuels produced generate approximately 88% less greenhouse gas (GHG) emissions compared to petroleum fuels given RFS assumptions. Manufacturing and transportation of feedstocks accounts for 92.19% of energy used in production giving a calculated EROI of 4.19 and 4.31 per kilogram of diesel and gasoline, respectively. Pessimistic estimates of soil organic carbon (SOC) loss result in GHG emissions that are approximately 83% lower. If a 1:0.5 displacement ratio of IH2 fuels is considered, the GHG emissions are about 76% lower without SOC loss and 66% lower with. This study demonstrates that while environmental impacts and EROI are sensitive to site selection and SOC estimates, there is a sufficient GHG emission reduction such that IH2 fuels are capable of meeting regulatory requirements. Conclusions Fuels produced at the facility result in a reduction in GHG emissions, but better site selection may result in less fuel being used in transportation. Reducing the quantity of electricity needed in n-th–generation facilities would also reduce environmental impacts while improving the EROI. The energy mix used to supply IH2 facilities should also be considered during the planning process. Finally, future research may be needed to ensure feedstocks recovered from logging operations match expectations