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Title: Analysis of wind turbine blade vibration and drivetrain loads
Creator: Ramakrishnan, Venkatanarayanan
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The reliability of wind turbines is a major issue for the industry. Drivetrain and blade failures are common, costly and not fully understood. Designers must thus examine and understand the key parameters that influence reliability. As wind turbines increase in size, the blades are designed to be more lightweight and flexible, increasing the potential for large-displacement oscillations during operation. This necessitates the incorporation of nonlinearity in the formulation of the blade model...
Show moreThe reliability of wind turbines is a major issue for the industry. Drivetrain and blade failures are common, costly and not fully understood. Designers must thus examine and understand the key parameters that influence reliability. As wind turbines increase in size, the blades are designed to be more lightweight and flexible, increasing the potential for large-displacement oscillations during operation. This necessitates the incorporation of nonlinearity in the formulation of the blade model to better understand the dynamics and stability characteristics. Also, oscillations in the blade impart dynamic loading onto the gearbox. Understanding these dynamic loads is essential for the design of reliable gears and bearings, and hence economically viable wind turbines. Traditional studies of wind turbines have focused on the aerodynamic performance of the blades, the reliability of gearbox and its components, grid connectivity and improvements in power distribution. The aspect of blade vibration from a dynamics point of view has garnered interest but not been fully developed and understood. In this work, the partial and ordinary differential equations that govern the in-plane and out-of-plane motion of a wind turbine blade subject to gravitational and aerodynamic loading are developed using Hamilton's principle and Lagrange formulations respectively. These differential equations include nonlinear terms due to nonlinear curvature and nonlinear foreshortening, as well as parametric and direct excitation at the frequency of rotation. The equations are reduced using an assumed uniform cantilevered beam mode to produce single second-order ordinary differential equations (ODE) to approximate the blade model for the case of constant rotation rate. Embedded in the ODE's are terms of a forced Mathieu equation with cubic nonlinearity. Different variations of the forced Mathieu equation are analyzed for resonances by using the method of multiple scales. The forced Mathieu equation has instabilities and resonances at multiple superharmonic and subharmonic frequencies. Second-order expansions are used to unfold the expressions that govern the amplitude of response at these critical resonances. The equations of motion (EOM's) also have regions of instability and we employ perturbation analysis to identify the stability transition curves of the system. These calculations compare well with numerical simulations for simple systems under study. The formulation is then extended to wind turbine blades. The effect of various parameters on the amount of blade oscillation is demonstrated using the amplitude-frequency curve. Aerodynamic forces on the wind turbine blades are calculated using the Blade Element Momentum (BEM) theory and its extensions. Commercial software, such as FAST, have also been used to simulate responses for specific blades to understand influence of various blade parameters. For current production wind turbine blades, the parameters are such that the superharmonic resonances are not excited significantly. From parametric studies of the blade EOM we can understand the parameter values at which these resonances become dominant. It is shown that as wind turbine blades become larger they are prone to superharmonic resonances, whose existence may not be within the scope of current design strategies. The amplitude of response at all resonances tend to become amplified for much larger blades. Both in-plane and out-of-plane responses will increase the loading at the rotor hub and consequently, increase the loads and moments on the wind turbine drivetrain. To capture the effect of increased loading on the wind turbine drivetrain, we follow two approaches. First, using RomaxWind, we model the 750 kW gearbox used as a part of the Gearbox Reliability Collaborative (GRC) headed by National Renewable Energy Labs (NREL). For this, we partnered with Romax Technology Ltd. to analyze the sensitivities of the load on the elements of the gearbox to variations in the input loads. Using the Romax gearbox model, we suggest methods to optimize the gear geometry to improve reliability of the drivetrain by minimizing influence of manufacturing and assembly tolerances and misalignments. We also designed novel approaches to predict gearbox vibration using the models and suggested changes that are required to improve the overall design of the gearbox (these have been implemented while manufacturing newer generations of the NREL GRC gearbox). Second, for the case of in-plane blade vibration, we use a simple torsional model of the wind turbine gearbox to study the influence of a time varying load on the torsional response of the drivetrain. The effect of increased loading on larger wind turbine systems is shown by scaling values of blade and gearbox properties. The fundamental work formulated in this thesis can be extended to more complex models to understand other system level dynamics of interest (multi-mode interaction, multi-blade resonance, etc.). More detailed formulation of aerodynamic loads (for example by using ONERA semi-empirical approach) would also improve model fidelity for predicting the influence of aerodynamic loads on blade vibration.
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Title: Urban and cluster agglomeration economies's effects on rural households in Asia
Creator: Hu, Chaoran
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Agglomeration effects play important roles for rural households in participating in farm and nonfarm activities. With the rapid growth of cities of different sizes and the development of food value chain, how these agglomerations of urban effects, networks, and food value chain clusters will affect rural households' participation in nonfarm employment and farm behavior (technology adoption) are not yet well known. The dissertation consists of three chapters that aim to assess the impacts of...
Show more"Agglomeration effects play important roles for rural households in participating in farm and nonfarm activities. With the rapid growth of cities of different sizes and the development of food value chain, how these agglomerations of urban effects, networks, and food value chain clusters will affect rural households' participation in nonfarm employment and farm behavior (technology adoption) are not yet well known. The dissertation consists of three chapters that aim to assess the impacts of these urban and cluster agglomeration economies' on rural households in Asia."--Excerpted from abstract.
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Title: Field modeling, symplectic tracking, and spin decoherence for EDM and muon g-2 lattices
Creator: Valetov, Eremey Vladimirovich
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "While the first particle accelerators were electrostatic machines, and several electrostatic storage rings were subsequently commissioned and operated, electrostatic storage rings pose a number of challenges. Unlike motion in the magnetic field, where particle energy remains constant, particle energy generally changes in electrostatic elements. Conservation of energy in an electrostatic element is, in practice, only approximate, and it requires careful and accurate design, manufacturing,...
Show more"While the first particle accelerators were electrostatic machines, and several electrostatic storage rings were subsequently commissioned and operated, electrostatic storage rings pose a number of challenges. Unlike motion in the magnetic field, where particle energy remains constant, particle energy generally changes in electrostatic elements. Conservation of energy in an electrostatic element is, in practice, only approximate, and it requires careful and accurate design, manufacturing, installation, and operational use. Electrostatic deflectors require relatively high electrostatic fields, tend to introduce nonlinear aberrations of all orders, and are more challenging to manufacture than homogeneous magnetic dipoles. Accordingly, magnetic storage rings are overwhelmingly prevalent. The search for electric dipole moments (EDMs) of fundamental particles is of key importance in the study of C and CP violations and their sources. C and CP violations are part of the Sakharov conditions that explain the matter-antimatter asymmetry in the universe. Determining the source of CP violations would provide valuable empirical insight for beyond-Standard-Model physics. EDMs of fundamental particles have not to this date been experimentally observed. The search for fundamental particle EDMs has narrowed the target search region; however, an EDM signal is yet to be discovered. In 2008, Brookhaven National Laboratory (BNL) had proposed the frozen spin (FS) concept for the search of a deuteron EDM. The FS concept envisions launching deuterons through a storage ring with combined electrostatic and magnetic fields. The electrostatic and magnetic fields are in a proportion that would, without an EDM, freeze the deuteron's spin along its momentum as the deuteron moves around the lattice. The radial electrostatic field would result in a torque on the spin vector, proportional to a deuteron EDM, rotating the spin vector out of the midplane. The principle of an anomalous magnetic dipole moment (MDM) measurement using a storage ring, shared by BNL's completed E821 Experiment and the ongoing E989 Experiment operated by Fermi National Accelerator Laboratory (FNAL), requires injecting muons into a magnetic ring at the so-called magic momentum. The magic momentum, as defined in this context, would freeze the muon's spin vector along its momentum if the anomalous MDM was zero. The spin precession in the horizontal plane relative to the momentum is proportional to the anomalous MDM. Storage rings for measurement of EDM and anomalous MDM present a new frontier in tracking code accuracy requirements. For accurate tracking of storage rings with electrostatic particle optical elements, it is necessary to model the fringe fields of such elements accurately, in particular, because not doing so provides a mechanism for energy conservation violation. However, the previous research on fringe fields tended to focus on magnetic rather than electrostatic particle optical elements. We will study and model the fringe fields of several electrostatic deflectors. Field falloffs of electrostatic deflectors are slower than exponential, and Enge functions are not suitable for accurate modeling of these falloffs. We will propose an alternative function to model field falloffs of electrostatic deflectors. We will use conformal mapping methods to obtain the main field of the Muon g-2 storage ring high voltage quadrupole, and we will calculate its fringe field and effective field boundary (EFB) using Fourier analysis. Furthermore, we will study tracking of storage rings with electrostatic elements using map methods. We will find that, for simultaneous symplecticity and energy conservation, it is only necessary to enforce symplecticity in COSY INFINITY. We will model and track several benchmark lattices - an electrostatic spherical deflector, a homogeneous magnetic dipole, and a proton EDM lattice - in COSY INFINITY and MSURK89, our in-house eighth order Runge-Kutta-Verner tracking code. Finally, we will investigate spin decoherence and systematic errors in FS and quasifrozen spin (QFS) lattices. Spin decoherence effects are similar in FS and QFS lattices, and spin decoherence in said lattices often remains in the same range over time, indicating the feasibility of EDM measurement using FS and QFS lattices."--Pages ii-iii.
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Title: Examining off-campus students' sense of belonging and behaviors in a town-gown context
Creator: Carter, Erin Hundley
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The current study emerged from the need to address student behavior issues in town-gown communities and the practical need to know more about off-campus students as central actors in these behaviors. Off-campus students have long been labeled as commuter students because of limited recognition of the known diversity within the commuter population (Dugan, Garland, Jacoby, & Gasiorski, 2008) and an absence of town-gown scholarship focused on college student residents of the local community ...
Show moreThe current study emerged from the need to address student behavior issues in town-gown communities and the practical need to know more about off-campus students as central actors in these behaviors. Off-campus students have long been labeled as commuter students because of limited recognition of the known diversity within the commuter population (Dugan, Garland, Jacoby, & Gasiorski, 2008) and an absence of town-gown scholarship focused on college student residents of the local community (Kemp, 2013). The current study sought to remedy the little attention given to off-campus students through the exploration of their sense of belonging to the local community, and in turn, how sense of belonging influenced behavior in the town-gown context. An American college town was the town-gown context chosen for the current study because of its capacity to showcase the unique influence the university has on the character of the town (Gumprecht, 2008). Using a stratified random sampling, the sample (n = 645) was drawn from the population of undergraduate students living off campus in the City of East Lansing, Michigan. Strata were determined based on residential density levels due to an interest in assessing how residential environments of varying densities influenced sense of belonging in off-campus students. The current study utilized sense of belonging and town-gown literature to guide the selection of exogenous and intervening predictor variables relevant in the town-gown context. These predictor variables included demographic characteristics (e.g., age, sex, race, year in school) and density categorization along with intervening variables such as environmental perceptions, social interactions, and behavior participation. Criterion variables included sense of belonging and positive and negative behavior participation. Hierarchical regression analyses were used to determine the extent these demographic and community factors influenced sense of belonging, as well as how sense of belonging influenced participation in positive and negative behaviors in the town-gown context. The study concluded off-campus students were a unique cohort in the student population, warranting future attention from scholars and practitioners. Sense of belonging was not predicted by demographic and density characteristics, but was positively influenced by perceptions of community (e.g., reliability, friendliness) and positive behavior participation (e.g., attending community events, utilizing city services). Number of roommates, semesters lived off-campus, and residential density associated with houses were positive predictors of behavior participation, both positive and negative. Environmental and social relations constructs were positive predictors of both positive and negative behavior participation. Sense of belonging was a positive predictor of positive behavior participation, but was not a predictor of negative behaviors. The discussion offers insights and direction for town-gown administrators tasked with creating policy and practical interventions aimed at supporting off-campus students, while also addressing the unique challenges stemming from student behaviors in the local community.
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Title: Examining the results of an intervention to influence factors of group dynamics in video conferencing learning environments
Creator: Cain, William Christopher
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "The following study was framed around a simple question: when a group of people is engaged in video conferencing, what sort of things can they do to improve their group dynamics? This is an important question for current and future educational practice because web-based video conferencing has increasingly become an important tool for use in online and distance education programs. Using computer-based audio and visual equipment, web-based video conferencing allows groups of students and...
Show more"The following study was framed around a simple question: when a group of people is engaged in video conferencing, what sort of things can they do to improve their group dynamics? This is an important question for current and future educational practice because web-based video conferencing has increasingly become an important tool for use in online and distance education programs. Using computer-based audio and visual equipment, web-based video conferencing allows groups of students and teachers to see and hear each other in real-time, providing a channel of communication that is often rich in information. Informal video chat, using applications like Skype, FaceTime, and Google Hangouts, has become a popular means of communication in much the same way as phone calls. Formal group video conferencing, however, is a different communication and interaction format from informal video chat, and many teachers and students often unfamiliar with rules and norms associated with it. For example, best practices literature on video conferencing stress that things like framing, lighting, proximity to the camera, and the composition of background can all affect the way a person is perceived by others. These factors can also affect the overall quality of the video conferencing session, making it easier or harder for people to hold sustained interactions with each other. In short, formal group video conferencing requires people to be mindful of certain things that they may not pay attention to when they are engaged in either face-to-face conversations or informal video chats. When people are not mindful, they can cause serious disruptions to overall group dynamics. Group dynamics play a role in any setting where people come together for a period of time. Forsyth defines a group as "two or more individuals who connected by and with social relationships" (Forsyth, 2009, p. 4). Dynamics are the interactions between and among factors in a context or system of elements. Group dynamics therefore refers to the qualities of interaction with one another in a group. Factors that influence group dynamics include morale, belongingness, tone, atmosphere, influence, participation, trust, leadership, conflict, competition, cooperation, etc. (Hanson, 2005). The goal of this study was to design an intervention based on a series of activities that instructors or facilitators could use with students in simulated high-stakes video conferencing learning environments. The results were illuminating but not in a way the author intended. The intervention at the heart of this study was not implemented as it was originally designed, which affected not only the results but the entire direction of analysis. This is not necessarily a bad thing. This study shows the importance of intervention design and the role that facilitators play in bringing the benefits of an intervention to those who need it. The different chapters in this dissertation discuss why the author felt this study was important and necessary, how he went about designing the central intervention, what the results suggest about intervention design and implementation, and his recommendations for future research in the area of group dynamics in video conferencing learning environments. It is the author's wish that readers gain a new appreciation for the complexity of research in this area, as well as a newfound or renewed interest in seeing this research continue."--Pages ii-iii.
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Title: Inhibitors of mycobacterium tuberculosis DosRST signaling and persistence
Creator: Zheng, Huiqing
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Tuberculosis (TB) is one of the most deadly infectious diseases in human history and is caused by the bacterium Mycobacterium tuberculosis (Mtb). Current TB therapy requires 6-9 months of treatment with four different antibiotics, including isoniazid, rifampin, ethambutol and pyrazinamide. However, due to the long course of TB therapy and the evolution of drug-resistant Mtb strains, first-line anti-mycobacterial drugs are not sufficient to control the TB epidemic. Therefore, it is urgent to...
Show moreTuberculosis (TB) is one of the most deadly infectious diseases in human history and is caused by the bacterium Mycobacterium tuberculosis (Mtb). Current TB therapy requires 6-9 months of treatment with four different antibiotics, including isoniazid, rifampin, ethambutol and pyrazinamide. However, due to the long course of TB therapy and the evolution of drug-resistant Mtb strains, first-line anti-mycobacterial drugs are not sufficient to control the TB epidemic. Therefore, it is urgent to develop new drugs with novel targets to shorten the course of therapy, control the spread of drug-resistant TB and eradicate this deadly disease. In response to host immune cues, Mtb modulates its metabolism to establish a state of low metabolic activity called non-replicating persistence (NRP). During NRP, Mtb can remain viable in the host without causing disease symptoms, a state known as latent TB. DosRST is a two-component regulatory system that plays an essential role to establish and maintain NRP in Mtb. It is induced by host immune stimuli, such as hypoxia, carbon monoxide and nitric oxide, through the histidine kinase sensors DosS and DosT. The response regulator DosR regulates about 50 genes in the dormancy regulon. NRP bacilli are problematic for two reasons: 1) they are insensitive to several anti-mycobacterial agents and drive the long course of TB therapy; and, 2) they can resuscitate for growth once the immune system weakens, thereby serving as a source for reactivation of disease and infectious transmission of the Mtb. Therefore, inhibiting the DosRST pathway may help reduce the population of NRP bacteria during infection and thus function to reduce drug tolerance and shorten TB treatment. This dissertation presents a whole-cell phenotypic high-throughput screen of a ~540,000 compound small-molecule library. The screen employed a DosR-dependent, hypoxia-inducible fluorescent reporter strain, CDC1551(hspX::GFP), and successfully identified six distinct, novel chemical inhibitors of DosRST signaling, named HC101A-106A. Physiological and mechanistic studies were performed to characterize HC101-104 and HC106A. All five inhibitors are shown to inhibit genes of the DosRST regulon and persistence-associated physiologies, such as triacylglycerol accumulation. HC101A, HC102A, HC103A and HC106A also reduce Mtb survival when cultured under strongly hypoxic conditions. UV-visible spectroscopy studies show that HC101A (artemisinin) and HC106A target the heme group of sensor kinases DosS/T via distinct mechanisms. For example, artemisinin modulates the redox status of DosS/T and alkylates the heme to form artemisinin-heme adducts, whereas HC106A interacts with DosS heme in a similar manner to direct CO-heme or NO-heme interactions. In contrast, HC102A and HC103A do not target the heme group, but instead inhibit sensor kinase autophosphorylation activity. Electrophoretic mobility assays suggest that HC104A functions by directly inhibiting DosR DNA binding activity. Overall, this dissertation provides proof-of-concept that multiple components of the DosRST pathway can be targeted by small molecules to inhibit Mtb persistence and antibiotic tolerance. Additionally, this dissertation presents the discovery of a new chemical inhibitor, HC2091, that kills Mtb by targeting the mycolic acid transporter MmpL3. MmpL3 is an essential protein that functions to transport trehalose monomycolate across mycomembranes for trehalose dimycolate biosynthesis. HC2091 is bactericidal against Mtb in a dose- and time- dependent manner in vitro. It also has activity against Mtb inside of macrophages. Whole genome sequencing spontaneous mutants resistant to HC2091 identified five single nucleotide variants primarily located in the C-terminus of MmpL3, and HC2091-treated Mtb exhibits decreased mycolic acid synthesis, thus supporting that MmpL3 is the target of HC2091.
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Title: Guilt, empathy, and compliance in a naturalistic moral scenario : predicting prosocial and externalizing behavior in 3-7-year-old children
Creator: Listro, Caitlin J.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Current science offers only limited answers concerning the development of empathy disturbances. Indeed, few studies have attempted to empirically identify the developmental trajectory of empathy to define either normal or aberrant developmental patterns. The present study aimed to use an observational approach to assess empathy, guilt, and obedience in children, and to validate this approach by exploring how these observational measures of child moral behavior associated with characteristics...
Show moreCurrent science offers only limited answers concerning the development of empathy disturbances. Indeed, few studies have attempted to empirically identify the developmental trajectory of empathy to define either normal or aberrant developmental patterns. The present study aimed to use an observational approach to assess empathy, guilt, and obedience in children, and to validate this approach by exploring how these observational measures of child moral behavior associated with characteristics theoretically linked to moral development and antisocial behavior. We utilized a videotaped Picture Tearing task in which the child is presented with a moral dilemma. Trained coders rated the tasks for several child behaviors (e.g. guilt, gaze avoidance, defiance) using a coding scheme adapted from the Lab-TAB (Goldsmith et al., 1993). Variations in moral behavior were investigated using person-centered (cluster analysis) and variable-centered (factor analysis) methods, then associations between resulting behaviors and other relevant child characteristics (temperament, externalizing behaviors) were examined concurrently and over time. In general, results indicated that empathic verbalizations and defiance were consistently associated with externalizing pathology. This association was observed concurrently; empathy did not predict externalizing over time. Overall, these results suggest that compliant without complaint is the most adaptive response at this age. Furthermore, the Picture Tearing task does provide useful data about empathic behavior and its associations in young children. Recommendations are made for adaptations to the task and coding scheme to improve the measurement of moral behavior in future research.
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Title: Defining the characteristics and roles of functional genomic sequences using computational approaches
Creator: Lloyd, John P.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Advances in biotechnology have provided a wealth of sequencing data that is transforming our view of a genome. Eukaryotic genomes, initially thought to contain discrete genes in a sea of non-functional DNA, have been found to exhibit pervasive biochemical activity, particularly transcription. However, whether this biochemical activity is functional (i.e. under evolutionary selection) or the result of noisy activity of cellular machinery represents a fundamental debate of the post-genome era....
Show more"Advances in biotechnology have provided a wealth of sequencing data that is transforming our view of a genome. Eukaryotic genomes, initially thought to contain discrete genes in a sea of non-functional DNA, have been found to exhibit pervasive biochemical activity, particularly transcription. However, whether this biochemical activity is functional (i.e. under evolutionary selection) or the result of noisy activity of cellular machinery represents a fundamental debate of the post-genome era. The research described in this dissertation focuses on two open questions confronting genome biology: 1) Where are the functional elements within a genome? 2) What roles are functional elements performing? For the first question, I focused on transcribed regions in unannotated, intergenic regions of genomes, which represent functionally ambiguous sequences. To determine which and how many intergenic transcribed regions (ITRs) represent functional sequences, machine learning-based function prediction models were established using Arabidopsis thaliana as a model. The prediction models were able to successfully distinguish between benchmark functional (phenotype genes) and non-functional sequences (pseudogenes) using evolutionary, biochemical, and sequence-based structural features. When applied to ITRs, 400303% of ITRs were predicted as functional, suggesting ITRs primarily represent transcriptional noise. I further investigated the evolutionary histories of ITRs in four grass (Poaceae) species. ITRs were found to be primarily species-specific and exhibit recent duplicates, with rare examples of ancient duplicate retention. In addition, ITR duplicates and orthologs were usually not expressed. Function prediction models were also generated in Oryza sativa (rice) that predicted 600303% of rice ITRs as nonfunctional. The results of function prediction models and evaluating evolutionary histories both suggest ITRs are primarily non-functional sequences. However, I also provide a list of potentially-functional ITRs that should be considered high priority targets for future experimental studies. For the second question, I established a machine learning framework to predict mutant phenotypes, which provide potent evidence for the role of a gene. Phenotype predictions were focused on essential genes (those with lethal mutant phenotypes) in A. thaliana, as these genes represent a historically well-studied group. Combining 57 expression, duplication, evolutionary, and gene network characteristics through machine learning methods accurately distinguished between genes with lethal and non-lethal mutant phenotypes. Additionally, essential gene prediction models could be applied across species; essential gene prediction models generated in A. thaliana could identify essential genes in rice and Saccharomyces cerevisiae. Thus, machine-learning represents a promising avenue of prioritization of candidate genes for large-scale phenotyping efforts. Overall, the research described in this dissertation highlight computational approaches as highly effective in defining functional sequences and classifying the likely roles of genes."--Pages ii-iii.
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Title: ResBos2 : precision resummation for the LHC ERA
Creator: Isaacson, Joshua Paul
Date: 2017
Collection: Electronic Theses & Dissertations
Description: With the precision of data at the LHC, it is important to advance theoretical calculations to match it. Previously, the ResBos code was insufficient to adequately describe the data at the LHC. This requires an advancement in the ResBos code, and led to the development of the ResBos2 package. This thesis discusses some of the major improvements that were implemented into the code to advance it and prepare it for the precision of the LHC.The resummation for color singlet particles is improved...
Show moreWith the precision of data at the LHC, it is important to advance theoretical calculations to match it. Previously, the ResBos code was insufficient to adequately describe the data at the LHC. This requires an advancement in the ResBos code, and led to the development of the ResBos2 package. This thesis discusses some of the major improvements that were implemented into the code to advance it and prepare it for the precision of the LHC.The resummation for color singlet particles is improved from approximate NNLL+NLO accuracy to an accuracy of N$^3$LL+NNLO accuracy. The ResBos2 code is validated against the calculation of the total cross-section for Drell-Yan processes against fixed order calculations, to ensure that the calculations are performed correctly. This allows for a prediction of the transverse momentum and $\phi^*_{\eta}$ distributions for the $Z$ boson to be consistent with the data from ATLAS at a collider energy of $\sqrt{s}=8$ TeV. Also, the effects of choice of resummation scheme are investigated for the Collins-Soper-Sterman and Catani-deFlorian-Grazzini formalisms. It is shown that as long as the calculation of each of these is performed such that the order of the $B$ coefficient is exactly 1 order higher than that of the $C$ and $H$ coefficients, then the two formalisms are consistent. Additionally, using the improved theoretical prediction will help to reduce the theoretical uncertainty on the mass of the $W$ boson, by reducing the uncertainty in extrapolating the $\frac{d\sigma}{dp_T^W}$ distribution from the data for the $\frac{d\sigma}{dp_T^Z}$ distribution by taking the ratio of the theory predictions for the $Z$ and $W$ transverse momentum. In addition to improving the accuracy of the color singlet final state resummation calculations, the ResBos2 code introduces the resummation of non-color singlet states in the final state. Here the details for the Higgs plus jet calculation are illustrated as an example of one such process. It is shown that it is possible to perform this resummation, but the resummation formalism needs to be modified in order to do so. The major modification that is made is the inclusion of the jet cone-size dependence in the Sudakov form factor. This result resolves, analytically, the Sudakov shoulder singularity. The results of the ResBos2 prediction are compared to both the fixed order and parton shower calculations. The calculations are shown to be consistent for all of the distributions considered up to the theoretical uncertainty. As the LHC continues to increase their data, and their precision on these observables, the ability to have analytic resummation calculations for non-color singlet final states will provide a strong check of perturbative QCD.Finally, the calculation of the terms needed to match to N$^3$LO are done in this work. Once the results become sufficiently publicly available for the perturbative calculation, the ResBos2 code can easily be extended to include these corrections, and be used as a means to predict the total cross-section at N$^3$LO as well.
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Title: Part A : iridium catalyzed C-H borylation of arenes ; engineering selectivity by ligand design. Part B: Z-selective palladium catalyzed cross coupling of E-vinyl germanes
Creator: Miller, Susanne L.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: ABSTRACTPART A: IRIDIUM CATALYZED C-H BORYLATION OF ARENES; ENGINEERING SELECTIVITY BY LIGAND DESIGN.By Susanne L. MillerIridium catalyzed C-H borylation has gained popularity as a means to functionalize simple aromatic and heterocyclic substrates under mild conditions which tolerate a variety of functional groups. Initial efforts to develop this chemistry made use of sterically driven selectivity to achieve contra-electronic substitution patterns of aromatic and heterocyclic building blocks...
Show moreABSTRACTPART A: IRIDIUM CATALYZED C-H BORYLATION OF ARENES; ENGINEERING SELECTIVITY BY LIGAND DESIGN.By Susanne L. MillerIridium catalyzed C-H borylation has gained popularity as a means to functionalize simple aromatic and heterocyclic substrates under mild conditions which tolerate a variety of functional groups. Initial efforts to develop this chemistry made use of sterically driven selectivity to achieve contra-electronic substitution patterns of aromatic and heterocyclic building blocks that were not easily obtainable by conventional organic chemistry prevalent before the discovery of this chemistry in 1999. As methodology and substrate scope rapidly expanded, steric selectivity became a limitation, as more diverse substitution patterns and higher selectivities were sought. These limitations were partially overcome by the extensive development of directing groups which enabled more traditional ortho substitution patterns to be accessed by the same mild conditions that made Ir-C-H borylation popular. While steric limitations that result in mixtures by the standard borylation protocols can now be overcome by directing groups, a serious challenge remains for the meta-functionalization of substrates which lack common directing groups or have small substituents. This work seeks to address this limitation by ligand-directed selectivity which can be instituted by the rational design of catalysts and ligands to achieve different selectivity outcomes depending on the desired product. The design and development of ligands which make use of either steric or electronic properties to achieve a given outcome was realized, and borylation meta to fluorine in simple arenes which lack directing groups was achieved. By varying the substituents on this ligand framework, the selectivity of the borylation can be shifted from steric to electronic selectivity.PART B: Z-SELECTIVE PALLADIUM CATALYZED CROSS COUPLING OF E-VINYL GERMANES.Germanium cross coupling reactions were born out of efforts to replace toxic organo-tin reagents used in the Stille cross coupling reaction for the construction of C-C bonds. Initial interest in germanium as a transmetalation partner peaked in the mid to late 1990s, but eventually waned due to poor reactivity of organo-germanium reagents and the harsh conditions needed to activate Ge-C bonds towards cross coupling. One such effort from the Maleczka group in the early 2000s, although suffering from poor conversion and unreliable results, gained modest attention by displaying a reactivity distinct from typical Stille coupling selectivity. Instead of retention of geometry, the major product of the E-vinyl germanium coupling reaction exhibited inverted Z- olefin geometry. In the reverse case, Z-vinylgermanes likewise gave inverted E-olefins as the major coupling products. Early studies of the reaction led to the hypothesis of a Heck-like insertion with subsequent germyl elimination to form the inverted product. The proposed mechanism featured a palladium-germyl elimination in preference to a possible b-H elimination. Based on the substrate scope and the organo-germane's required possession of a tertiary allylic alcohol, the Pd- Ge elimination theory was discarded in favor of the formation of a reactive epoxide intermediate, which eliminated germanium upon carbopalladation. The observation of the unactivated cross coupling of allylic germanium epoxides with iodo-arenes supported this hypothesis. Expansion of this chemistry was hampered by inconsistent results and a very narrow substrate scope. Further investigation suggested involvement of Pd nanoparticles.
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Title: How does a principal in Detroit Public Schools produce a productive learning environment within the current system?
Creator: Davenport, Marcus G.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: In this dissertation, the researcher investigates the success of productive learning environments in Detroit Public Schools. Using interviews with three productive principals from the Detroit school system, the researcher explores three related issues in public schooling. The first issue is the definition of a productive learning environment. By collecting answers from the principals about their definitions of productive learning environments, the researcher was able to find common themes....
Show moreIn this dissertation, the researcher investigates the success of productive learning environments in Detroit Public Schools. Using interviews with three productive principals from the Detroit school system, the researcher explores three related issues in public schooling. The first issue is the definition of a productive learning environment. By collecting answers from the principals about their definitions of productive learning environments, the researcher was able to find common themes. Among these common themes are: the safety of students, efficient hiring practices, team-centered efforts, and functioning school buildings. The second issue is about the obstacles that these principals face in creating a productive learning environment. The three principals presented many of their challenges in operating their schools, such as a lack funds, an unsafe environment, and a lack of qualified teaching staff. The third issue is the qualities that define productive principals in Detroit Public Schools. After comparing common traits and experiences between all three interviewed principals, the researcher identified several of these qualities, including open communication, acting as an instructional leader, being authoritative and energetic, and ability to build partnerships. The results of this dissertation will prove useful to urban school districts in Detroit and elsewhere in selecting future leaders and building productive learning environments.
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Title: The role of lateral hypothalamic neurotensin neurons in adaptive energy balance
Creator: Brown, Juliette Anne
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The lateral hypothalamic area (LHA), receives cues of energy and fluid status from the body and coordinates appropriate feeding, drinking and activity (e.g. adaptive responses) to ensure survival. The LHA contains many distinct populations of neurons, however, and it remains unclear how each of these contribute to energy balance. Here we sought to understand how LHA neurons expressing the neuropeptide neurotensin (LHA Nts neurons) coordinate distinct behaviors necessary for adaptive response...
Show moreThe lateral hypothalamic area (LHA), receives cues of energy and fluid status from the body and coordinates appropriate feeding, drinking and activity (e.g. adaptive responses) to ensure survival. The LHA contains many distinct populations of neurons, however, and it remains unclear how each of these contribute to energy balance. Here we sought to understand how LHA neurons expressing the neuropeptide neurotensin (LHA Nts neurons) coordinate distinct behaviors necessary for adaptive response and control of body weight. While activation of most LHA Neurons increases both feeding and drinking, activation of LHA Nts neurons specifically promotes drinking but reduces feeding. LHA Nts neurons may exert these divergent actions via distinct circuits, as they have been shown to modulate dopamine (DA) signaling and local orexin (OX) neurons. Consistent with this, we have distinguished two projection-specific and molecularly distinct subsets of LHA Nts neurons. One subset co-expresses Nts and the long form of the leptin receptor (LepRb), is activated by leptin and projects to the ventral tegmental area (VTA) and substantia nigra compacta (SNc); we refer to these as NtsLepRb neurons. A separate subset of LHA Nts neurons lacks LepRb, is activated by dehydration and does not project to the VTA or SNc; we refer to these as Nts Dehy neurons. Intriguingly, however, we found all LHA Nts neurons are similar in that they express the inhibitory neurotransmitter, GABA. We next investigated the role of the NtsLepRb subpopulation for adaptive response by studying mice lacking leptin signaling via Nts LepRb neurons. Loss of leptin regulation only via NtsLepRb neurons induced obesity, blunted adaptive response to leptin and to ghrelin (a hormonal activator of OX neurons) and dysregulated DA signaling. Finally, we defined the necessity of LHA Nts neurons for energy balance by genetically ablating or chemogenetically inhibiting them in adult mice. Prolonged loss of LHA Nts neurons decreased drinking, locomotor activity and deranged OX expression in target neurons that led to increased adiposity. By contrast, LHA Nts inhibition preserved OX expression but still blunted locomotor activity. Together these data suggest that LHA Nts neurons modulate physical activity that is not dependent on OX, but that the LHA Nts→OX circuit is necessary for regulation of drinking and adiposity. Collectively, our data show that LHA Nts neurons are necessary for regulation of adaptive energy balance, and that distinct subpopulations of LHA Nts neurons may control ingestive and locomotor behavior via OX-dependent and independent pathways. This work suggests that there may be unique LHA Nts circuits to regulate drinking, motivated feeding ingestive disorders such as obesity, anorexia nervosa, psychogenic polydipsia and dehydration.
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Title: Evolution and evolvability in changing environments
Creator: Canino-Koning, Rosangela
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "The specific meaning of the term 'evolvability' is heavily debated, but most definitions can be summarized as: the potential of populations and genomes to produce adaptive variation and complex structures in response to mutation and selection. Changing environments are thought to play a significant role in shaping and promoting evolvability through alternating selective pressures. In this dissertation, I will discuss my recent research on the interplay between changing environments,...
Show more"The specific meaning of the term 'evolvability' is heavily debated, but most definitions can be summarized as: the potential of populations and genomes to produce adaptive variation and complex structures in response to mutation and selection. Changing environments are thought to play a significant role in shaping and promoting evolvability through alternating selective pressures. In this dissertation, I will discuss my recent research on the interplay between changing environments, evolvability, genetic architecture, and the evolution of horizontal gene transfer (HGT), an information-rich mutagenic function that is ubiquitous in nature. Before delving into my own research, however, I begin in the first chapter by providing a survey of current literature on each of these topics, with emphases on how they are believed to arise, how they affect subsequent evolution, and how they relate to each other. Genetic architecture and population dynamics clearly have a complex interplay in ongoing evolutionary dynamics. Evolutionary history, population diversity, modularity, and task size all play a role in determining the location and characteristics of populations in genotype space, and alter the genotype to phenotype map that permits neutral genetic variation. All of these features contribute to evolvability. In Chapter 2, I demonstrate how changing environments provided a sufficient selective pressure to produce quasi-modular genetic architectures that allow for rapid adaptation to the meta-environment of environmental change. Horizontal gene transfer is a highly regulated, ubiquitous, and ancient mechanism for exchanging genetic material between unrelated organisms. In the third chapter, I explore conditions which may have led to the evolution of horizontal gene transfer through transformation, and identify mechanisms that might support its continued performance. In Chapter 4, I compare the fitness and phenotypic effects of the HGT process against other types of increasingly less information rich mutational operators. I demonstrate that not only is HGT selected for in harsh changing environments, but that other mutagenic instructions that contain less information, or provide lesser fitness benefits are not similarly selected for. In the fifth chapter, I explore the long-term evolutionary potential of populations evolved in changing environments by evolving two different populations, one evolved in a minimal changing environment, and the other in a rich changing environment, and exposing them to a brand new environment. I demonstrate that while populations adapted to harsh changing environments are indeed able to adapt quickly to previously seen environmental changes, that these populations do not fare as well in brand new environments. Rather, benign changing environments perform best in measures of task discovery and exploration. In the final chapter, I conclude with a synthesis of my results, along with implications for the field, as well as identification of some new directions for pursuing my research into changing environments."--Pages ii-iii.
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Title: Beyond the random brushings of birds : black women on the meaning of the saints to post-Katrina recovery of home
Creator: Gilbert, Marita Cori
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "The New Orleans Saints transformed themselves from worst to first in the National Football League (NFL), winning their first Super Bowl in franchise history five years after Hurricane Katrina. Observing New Orleans' unique celebratory culture, the media debated the team's success as symbolic of the recovery of the City. New Orleanians would disagree that this event, momentous as it was, connotes the work of recovering home is done. Instead, the Saints embodied a hopeful resilience. The team...
Show more"The New Orleans Saints transformed themselves from worst to first in the National Football League (NFL), winning their first Super Bowl in franchise history five years after Hurricane Katrina. Observing New Orleans' unique celebratory culture, the media debated the team's success as symbolic of the recovery of the City. New Orleanians would disagree that this event, momentous as it was, connotes the work of recovering home is done. Instead, the Saints embodied a hopeful resilience. The team functioned as a conduit to the practice of celebratory memorial, for which New Orleans is known--mourning sorrow through festive celebration. Celebrating the Saints (and their Super Bowl Championship season) exemplified the second line tradition--the cultural performance of home as a shared, embodied knowledge of transcendence blending a visual, emotional, and kinetic experience of narrative, rhythm, food, community, and resistance. Thus, the meaning of the Saints' success exceeded football--it provided a vehicle for New Orleans' cultural aesthetic of home. Still, there exists a dissonance between legitimated narratives and narratives constructed from lived experience--specifically those of black women, erased not only from the center of the "Saints as recovery" narratives but from disaster recovery narratives in their entirety. Black women's accounts were ignored, despite expressed intergenerational bonds with the team as fans and consumers, their experiences rendered undetectable. Indeed, the Saints are an important thread in the fabric of the post-Katrina recovery story. However, understanding the Saints as the story is a problematic act of epistemic silencing enacted against black women recovering home in real-time, possessing relevant narrative and theoretical contributions. This dissertation is a theoretical exercise, blending visual study and a black feminist epistemological framework to interrogate the narratives of black women on-the-ground to understand the meaning of the New Orleans Saints 2010 Super Bowl victory to the post-Katrina recovery of home. The project was designed as an 18-month ethnographic study, combining archival research, participant observation, and photo elicitation interviews with 7 black women (ages 23-81). Five images that depicted the Saints phenomenon as well as themes from extant literature accompanied a semi-structured interview schedule to empower participants as experts and encourage self-authored narratives describing the meaning of the Saints to the post-Katrina recovery of home. Findings suggest that the Saints' success is integral in the recovery of home--as the embodiment of New Orleans unique culture of celebratory memorial as step toward healing."--Abstract.
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Title: Feeling to see : black graduate student women (re)membering black womanhood through study abroad
Creator: Green, Qiana
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This qualitative research study illuminates the lived experiences of Black graduate student women who study abroad. I provide insights on how these students made meaning of themselves through study abroad. I utilized sista circle methodology, a culturally responsive methodology, to examine the study abroad experiences of 23 Black graduate student women. A critical lens was used to analyze and examine how relationships and interactions influenced participants' meaning making of themselves...
Show moreThis qualitative research study illuminates the lived experiences of Black graduate student women who study abroad. I provide insights on how these students made meaning of themselves through study abroad. I utilized sista circle methodology, a culturally responsive methodology, to examine the study abroad experiences of 23 Black graduate student women. A critical lens was used to analyze and examine how relationships and interactions influenced participants' meaning making of themselves through study abroad. Drawing on Black Feminist Epistemology (Collins, 2009), Endarkened Feminist Epistemology (Dillard, 2000), experiential learning, (Michelson, 1998), and participants' narratives, I created a heuristic representation of meaning making through study abroad. I focused my analysis of participants' narratives through three braided areas of inquiry: (a) influences of relationships and interactions with faculty, trip leaders, and peers; (b) interactions with Blackness in study abroad contexts; and (c) healing through relationships and interactions during study abroad. Findings revealed the importance of returning to one's body as a site of knowledge production. Relationships and interactions during study abroad triggered emotional and physical responses experienced in their bodies. As adult learners, "trigger events" are necessary for learning and re-negotiating new identities (Biniecki & Conceição, 2014, p. 39). These events challenged former knowledge and prompted the Black women in this study to expand their knowledge of self. Thus, participants' narratives challenge the Western notion of meaning making that emphasizes cognitive learning. Instead, the Black women in this study utilized their bodies as sites of cultural knowledge production. Triggering events prompted physical and emotional responses during study abroad and influenced participants (re)membering of Black womanhood. These findings contribute to the academic dialogue on Black graduate student women's study abroad experiences (as one aspect of higher education). This study can inform future inquiry into examining intersecting identities in transnational contexts, embodied nature of knowledge, and transformative learning in study abroad. I expand on these notions, and others, as I conclude this dissertation with recommendations for practice, and implications for research and theory.
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Title: Financial constraints and financing decision in cross-border mergers & acquisitions : evidence from the US retail sector
Creator: Li, Jie (Graduate of Michigan State University in retailing)
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Many global retailers in mature markets employ mergers and acquisitions (M&A) as an essential strategic tool to expand into foreign markets. Cross-border M&As are more likely to face financial constraints than other forms of investment and domestic deals. When facing different levels and types of financial constraints, retail Multinational Enterprises (MNEs) tap various capital resources to fund their overseas expansion. Effective, timely financing decision could enable retailers to capture...
Show moreMany global retailers in mature markets employ mergers and acquisitions (M&A) as an essential strategic tool to expand into foreign markets. Cross-border M&As are more likely to face financial constraints than other forms of investment and domestic deals. When facing different levels and types of financial constraints, retail Multinational Enterprises (MNEs) tap various capital resources to fund their overseas expansion. Effective, timely financing decision could enable retailers to capture opportunities that they would otherwise have forgone. More importantly, an acquirer's M&A financing decision may sequentially influence its future cash flows, financial leverage, subsequent financial decisions, ownership structure and profits of both acquirer and target. Given the substantial presence of financial constraints and the importance of financing strategy in cross-border M&As, the present study attempts to answer the research question: how do different types and degrees of financial constraints affect U.S. retail MNEs' cross-border M&A financing decisions? Based on cross-border takeovers with a U.S. retailer identified as the acquirer during 2002-2014, our findings suggest that abundant cash reserves and large unused debt capability are associated with Cash Only financing. We also find that acquirers are more likely to adopt Debt financing than Equity financing when they face meidum to high level of internal constraints and have large unused debt capbilities. Because majority of our sample are medium to large-sized, established, publicly-listed firms, our data do not support the hypotheses that the validity of pecking order would be challenged as the result of credit rationing in the debt market. As a result, our analysis partially supports the overarching hypothesis that Pecking Order Theory is conditional on financial constraints. The financial crisis was not found to have a significant impact on the choice between Cash Only and Debt financing. But our data is consistent with the observation that equity markets were the most volatile during the financial crisis. Our study should shed light on retail MNEs' best financing practices based on their financial conditions and should also inform policy makers' resource allocation decisions to help firms survive during economic tough times.
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Title: An assessment of protective factors in predicting juvenile reoffending
Creator: Barnes, Ashlee R.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Juvenile court practitioners use risk assessment to evaluate level of risk and criminogenic areas of need to determine the most appropriate consequence for young offenders, and to determine goals for case planning. Recently, juvenile court practitioners and researchers have gained interest in evaluating young offenders' internal and external strengths, or protective factors. Some scholars assert that incorporating measures of protective factors into the risk assessment process can increase...
Show moreJuvenile court practitioners use risk assessment to evaluate level of risk and criminogenic areas of need to determine the most appropriate consequence for young offenders, and to determine goals for case planning. Recently, juvenile court practitioners and researchers have gained interest in evaluating young offenders' internal and external strengths, or protective factors. Some scholars assert that incorporating measures of protective factors into the risk assessment process can increase the accuracy of identifying young offenders' odds of recidivating. Relatively few juvenile risk assessment validation studies have evaluated the predictive validity of protective factor items. Moreover, protective factor items that are included in many existing risk assessment tools are narrow in scope, particularly within family-, school-, and community-level protective factor domains. The current study examined the relationship between protective factors and recidivism for 278 young probationers from a Midwestern juvenile county court. The study was conducted in two parts. First, a strengths-based measure of risk of recidivism (Protective Factors for Reducing Juvenile Reoffending, PFRJR) was created and its factor structure and reliability was evaluated. Second, the predictive validity, incremental validity, and differential predictive validity of the PFRJR were examined. In the first study, the author identified two factors, Individual/Community and Family/Social; both subscales demonstrated strong internal consistency. In the second study, the author found no significant differences in mean level composite protective factor scores across gender, however African American offenders had significantly lower protective factor scores than White offenders. The PFRJR significantly predicted recidivism and time-to-recidivism, and produced AUC effect sizes that ranged from small to large for the total sample and across young offender subgroups. The author did not find evidence of differential predictive validity across gender, however the author found differential predictive validity by race/ethnicity. Regarding the incremental validity of protective factor scores, the PFRJR composite scores did not increase the amount of variance explained in recidivism after accounting for the variance explained by composite risk factor scores (as measured by the Youth Level of Service/Case Management Inventory). Broadly, the current study highlights the feasibility of integrating a complementary strengths-based measure into traditional risk assessment procedures. Findings from the current study also contributed to the paucity of risk assessment validation studies that emphasized the predictive validity of protective factor scores.
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Title: Evolution of decision-making systems
Creator: Schossau, Jorden D.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Adaptive biological or engineered systems are adaptive because they can make decisions. Some systems such as viruses use their molecular composition – genetic information – to decide when to become lysogenic (dormant) or lytic (active). Others, such as self-driving cars, must use spatiotemporal information about obstacles, speed, and previous signs to determine when to turn or begin braking. Computational models of systems allow us to both engineer better systems, and create better scientific...
Show moreAdaptive biological or engineered systems are adaptive because they can make decisions. Some systems such as viruses use their molecular composition – genetic information – to decide when to become lysogenic (dormant) or lytic (active). Others, such as self-driving cars, must use spatiotemporal information about obstacles, speed, and previous signs to determine when to turn or begin braking. Computational models of systems allow us to both engineer better systems, and create better scientific understanding about the dynamic world. The practice of modeling decision-making started with the study of interactions between rational agents on the spectrum of conflict and cooperation began with Von Neumann and Morgenstern's Theory of Game and Economic Behavior.Scenarios, called "games", are models designed and studied to increase understanding of conflict and cooperation between these agents. The games discussed here are Prisoner's Dilemma and Volunteer's Dilemma. Modern methods of analysis for games involving populations of interacting agents fail to predict the final strategy distribution among all agents. In chapter 2 I develop a new computational agent-based simulation used as an inductive study system to compare the deductive predictive capabilities of an analytical model that is capable of predicting the final distribution under idealized conditions. Lastly, I show a novel finding that the agent-based model suggests probabilistic, or mixed, strategies (such as probabilistic gene expression) are a result of the development and maintenance of cooperation in Volunteer's Dilemma.Game theory fails to provide tractable models for more complex decision-making situations, such as those with complex spatial or temporal dimensions. In these cases an algorithm of conditional logic may be used to simulate decision-making behavior. Yet still there are systems for which the use of an algorithm as a model is inadequate due to incomplete knowledge of the system. Perhaps the model makes too many generalizations, is limited by atomic discretization, or is otherwise incomplete. In these cases it is useful to compensate for deficits by using probabilistic logic. That is, we assume that a stochastic process can roughly describe those subprocesses not fully modeled.Lastly, algorithms as decision strategies can incorporate temporal information in the decision-making process. There are two ways temporal information can be used in an individual's conditional logic: evolutionary, and lifetime. The evolutionary approach has proved much more flexible as a means to discover and tune models of unknown decision-making processes. Neuroevolution is a machine learning method that uses evolutionary algorithms to train artificial neural networks as models of decision-making systems. There is currently a wide diversity of methods for neuroevolution that all share common structures of the types of problems being solved: those generally being cognitive tasks. Toward this end it would be useful if there were some properties common to all cognitive systems that could be incorporated into the optimizing objective function in order to enhance or simplify the evolutionary process. In chapter 3 and 4 I explore new methods of improving model discovery through neuroevolution and discuss the applicability of these methods for probabilistic models.
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Title: Negotiating fairness : a feminist political ecology of fair trade and organic coffee production in Minas Gerais, Brazil
Creator: Meuninck, Rebecca (Rebecca Mari)
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This dissertation uses a feminist political ecology approach to explore the "fairness" of Fair Trade certification. I do this by examining the gendered social, economic, and environmental impacts of Fair Trade at COOPFAM, a Fair Trade and organic certified coffee cooperative in Minas Gerais, Brazil. Fair Trade is a third-party certification system that attempts to address social and economic inequalities facing small-scale coffee farmers, through floor prices and social development premiums....
Show moreThis dissertation uses a feminist political ecology approach to explore the "fairness" of Fair Trade certification. I do this by examining the gendered social, economic, and environmental impacts of Fair Trade at COOPFAM, a Fair Trade and organic certified coffee cooperative in Minas Gerais, Brazil. Fair Trade is a third-party certification system that attempts to address social and economic inequalities facing small-scale coffee farmers, through floor prices and social development premiums. In return, it requires equitable labor practices, adherence to environmental standards, and freedom of association and democratic decision-making within cooperatives. Fair Trade has grown over the past two decades, due to the liberalization of global coffee markets, and an evolution of consumers' desires which favor more socially and environmentally just coffees. In light of this growth, it is critical to ask, how "fair" is Fair Trade, is it equally fair for all farmers, and how do farmers perceive "fairness"? I use multi-sited ethnographic techniques to explore the "fairness" of Fair Trade; I followed the "thing" (coffee), and "the discourse" (the negotiation of fairness) along COOPFAM's international supply chain (Marcus 1995). I conducted interviews with and participant observation among Brazilian Fair Trade farmers and cooperative administrators, as well as foreign coffee buyers, Fair Trade activists, and certifiers. I then analyze the power dynamics in the Fair Trade system at the local level in homes, at the meso level at the cooperative, and at the macro level with their international partners. I argue that Fair Trade is advantageous for COOPFAM and her farmers, because of the assets they leveraged to overcome the common barriers that have stymied other cooperatives and farmers from obtaining Fair Trade and organic certification. Through Fair Trade, COOPFAM farmers enjoy access to international markets and networks of actors in the supply chain that connect the cooperative with social and economic programs. Moreover, Fair Trade provides an economic safety net for the farmers and the cooperative to experiment with novel production practices, technologies, and emerging certification systems. However, through an examination of COOPFAM's experimentation with new certification systems, the challenges of applying global standards to coffee production surface. Standards, first created to meet the needs of farmers in one locale and the desires of consumers in foreign lands, do not always translate well to other cultures and modes of production. Farmers and cooperatives negotiate these standards with buyers and certifiers, but they are on unequal footing. By examining Fair Trade through a gendered lens, we can see that the system is fairer for some farmers than it is for others. Poorer farmers, those who live far away from the cooperative, unmarried women, and widows are not as well served by the cooperative and may struggle to produce enough high-quality coffee to support their families. My exploration of farmers' livelihood strategies shows that Fair Trade coffee production alone is not sufficient to sustain farming families. Rather, COOPFAM's success and the sustainability of Fair Trade as a production system are reliant on farming families' diversity of livelihood strategies and continual innovation to improve coffee quality.
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Title: Synthesis and aromatization of biobased cyclohexenes
Creator: Nishizawa-Brennen, Yukari
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "In recent years, the cost of petrochemicals has declined by increasing production of unconventional gases such as shale gas, tight gas and coalbed methane. The main component of the unconventional gases is methane. Aromatic compounds are ubiquitous in commodity, specialty and pharmaceutical chemicals. Many aromatic chemicals are derived from benzene, toluene and xylenes (BTX), which could be derived from methane. Biobased aromatic chemicals production may appear unnecessary since we can...
Show more"In recent years, the cost of petrochemicals has declined by increasing production of unconventional gases such as shale gas, tight gas and coalbed methane. The main component of the unconventional gases is methane. Aromatic compounds are ubiquitous in commodity, specialty and pharmaceutical chemicals. Many aromatic chemicals are derived from benzene, toluene and xylenes (BTX), which could be derived from methane. Biobased aromatic chemicals production may appear unnecessary since we can produce BTX from methane. However, other factors need to be considered such as climate change, avoidance of toxic starting materials and/or byproducts, and significant consumer preference for biobased products. Because aromatics are generally toxic to microbes, biobased aromatic compounds are often synthesized from nontoxic biobased intermediates. An ideal strategy is a synthesis of biobased hydroaromatics that can be either dehydrated or dehydrogenated to aromatics in a single step. We can perform elimination reactions on biobased cyclohexenes possessing appropriately placed leaving groups. In the absence of leaving groups, dehydrogenation reactions need to be employed. This thesis focuses on biobased cyclohexenes that are aromatized either by dehydration reactions or by dehydrogenation reactions."--Page ii.
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