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Title: A descriptive analysis of beginning specialty crop farmer training programs in Michigan
Creator: Comer, Donald M.
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Michigan's diverse agricultural landscape provides multiple perspectives when considering the need for beginning farmer training. One perspective is a $104 billion industrial agricultural industry, with an ageing and decreasing farming population, and consolidation of land (MDARD, 2019). Another perspective is a growing movement of smaller-scale, regenerative farms with an emphasis on direct marketing, minimizing external inputs and improving ecosystem services. In the middle is an emerging...
Show moreMichigan's diverse agricultural landscape provides multiple perspectives when considering the need for beginning farmer training. One perspective is a $104 billion industrial agricultural industry, with an ageing and decreasing farming population, and consolidation of land (MDARD, 2019). Another perspective is a growing movement of smaller-scale, regenerative farms with an emphasis on direct marketing, minimizing external inputs and improving ecosystem services. In the middle is an emerging population of passionate and inexperienced growers that need training to get started, and farmer training organizations with their own challenges to meet farmers' needs. The purpose of this descriptive study was to survey Michigan's beginning specialty crop farmer training organizations in order to inform educators, policy makers, and beginning farmers. The research provides a description of existing training programs, the types of farmers participating in those programs, and current collaborations among the organizations. The results showed that Michigan has a diverse number of training options, but most operate independently of each other and lack resources to provide the best possible services. Recommendations include developing a state-wide systems approach to training and developing a central body or network that will aid in collaboration, resource allocation, and policy development. With this research as a foundation, it will be possible to complete a more comprehensive analysis, and to begin building a network that will provide future farmers to meet Michigan's agricultural challenges.
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Title: A detailed study of the gamma-ray nova V1324 Sco
Creator: Finzell, Thomas Michael Broen
Date: 2017
Collection: Electronic Theses & Dissertations
Description: It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays, but the mechanisms involved in the production of the gamma-rays are still not well understood. We present here a comprehensive, multi-wavelength dataset---from radio to X-rays---for the most gamma-ray luminous classical nova to-date, V1324 Sco. Using this dataset, we show that V1324 Sco is a canonical dusty Fe-II type nova, with a reddening of E(B-V) = 1.16 +\- 0.12, a distance > 6.5 kpc, a bulk ejecta...
Show moreIt has recently been discovered that some, if not all, classical novae emit GeV gamma-rays, but the mechanisms involved in the production of the gamma-rays are still not well understood. We present here a comprehensive, multi-wavelength dataset---from radio to X-rays---for the most gamma-ray luminous classical nova to-date, V1324 Sco. Using this dataset, we show that V1324 Sco is a canonical dusty Fe-II type nova, with a reddening of E(B-V) = 1.16 +\- 0.12, a distance > 6.5 kpc, a bulk ejecta velocity of 1150 +/- 40 km/s and an ejecta mass of 2.0 +\- 0.4 * 10^-5 M_{Solar}. However, despite its seeming normalcy, there is also evidence for complex shock interactions, including the aforementioned gamma-rays and early time high-brightness temperature radio emission. To explain how a nova can be simultaneously ordinary and have the highest gamma-ray luminosity to date, we present a simplified model of the ejecta in which the strength of gamma-ray emission is set by properties of a fast ejecta component that collides with a slower component to produce shocks. We conclude this detailed study of V1324 Sco by showing how it has helped shape our understanding of the role of shocks in novae. Along with the study of V1324 Sco, this work also presents detailed methods for determining the reddening, distance, and filling factor of a classical nova from optical spectroscopy (using V1324 Sco as an example). We also provide detailed derivations for fitting nova radio light curves, to determine ejecta mass and velocity.
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Title: A dimensional comparison of selected Japanese gardens, classical Chinese gardens and modern Chinese gardens
Creator: Qu, Yige
Date: 2019
Collection: Electronic Theses & Dissertations
Description: The relationships between Japanese gardens and Chinese gardens have been studied and discussed for a long time. This study focuses on the topic by a quantitative method. A cluster analysis is conducted to define the similarities and differences between these two kinds of gardens. The distinctive varieties in the result shows the elements that presents the relationships most distinctively. For this study, the data is collected in both Chinese gardens and Japanese gardens in order to show more...
Show moreThe relationships between Japanese gardens and Chinese gardens have been studied and discussed for a long time. This study focuses on the topic by a quantitative method. A cluster analysis is conducted to define the similarities and differences between these two kinds of gardens. The distinctive varieties in the result shows the elements that presents the relationships most distinctively. For this study, the data is collected in both Chinese gardens and Japanese gardens in order to show more persuasive results illustrating the relationships between these gardens. Principal component analysis is used to analyze the data, and to show intuitional visual results by graphs. The statistic software output shows a set of principal components. First three principal components contain roughly 59% of the variance. The design elements that distinctively effect the relationship are also indicated in the results, which lead further interpretation about the topic. The scatter graph shows distinct differences between Chinese gardens and Japanese gardens. Major elements divided Chinese gardens and Japanese gardens, traditional gardens and modern gardens, and Japanese gardens. This research can be used by garden designers and researchers to gain a insight concerning of the similarities and differences between Japanese gardens and Chinese gardens.
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Title: A finite element study of human thigh area in seated posture for pressure ulcer prediction and prevention
Creator: Chen, Sheng
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Pressure ulcers (PUs), also known as pressure sores, are localized damage to the skin and underlying tissues, usually occurring over a bony prominence and caused by sitting or lying in one position for long time. PUs are a detriment to the well-being of people who lose their mobility either permanently or temporarily, and high morbidity and mortality are associated with PUs. Although the initiating mechanism of PUs is still unclear, it is commonly accepted that internal normal and shear...
Show morePressure ulcers (PUs), also known as pressure sores, are localized damage to the skin and underlying tissues, usually occurring over a bony prominence and caused by sitting or lying in one position for long time. PUs are a detriment to the well-being of people who lose their mobility either permanently or temporarily, and high morbidity and mortality are associated with PUs. Although the initiating mechanism of PUs is still unclear, it is commonly accepted that internal normal and shear stresses, due to the presence of unrelieved external loads, play a central role in the formation and development of these wounds. Despite the significance of internal stresses in PUs formation, interfacial pressures, which are a surface measure of stress, are the indicators commonly used to develop practices and protocols to minimize loading on the soft tissue. However, no direct correlation exists between interfacial pressure and internal stresses of soft tissue. Therefore, tools and methods that can show internal distributions of soft tissue's stresses and strains as a response to external loading are needed.The ability of finite element (FE) models to accurately represent the anatomical structure of the leg and buttocks area and to estimate the localized stress/strain fields within highly deformable media, makes them powerful tools to investigate soft tissue response to external loadings. Despite the significant advancement previous studies have achieved, there are still important aspects in human thigh-buttock soft tissue modeling area that need to be improved. Two challenges are identified in this dissertation: 1) Microstructurally motivated skin modeling for an individual skin layer in finite element model. 2) Parameters estimation associated with large deformations.To address the first challenge, a microstructurally based constitutive model is proposed to describe the mechanical behavior of skin. The constitutive model incorporated the distribution of collagen fiber bundle orientations and relative collagen content measured from histology, and shows good agreement with the tensile test data.To address the second challenge, an optimization procedure that is able to match nonlinear behaviors between FE simulation and in vivo experimental data is developed. The difference between 3D and semi-3D model is quantified, and the accuracy of four commonly used constitutive model representing soft tissue nonlinear mechanical behavior is compared.Finally, a thigh FE model that has detailed anatomical representation of different soft tissue types, i.e., skin, fat, and muscle, is developed. The subject-specific in vivo experimental data are used to inform the optimization procedure to obtain best-fit constitutive parameters for different soft tissue types. The research in this dissertation provides an approach to describe the in vivo mechanical behavior of soft tissues in thigh-buttock area accurately through FE modeling. The constitutive parameters informed by in vivo data in this dissertation are valuable to facilitate future FE modeling studies to achieve accurate internal stress/strain distribution of soft tissues in thigh-buttock area.
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Title: A genomic investigation of Marek's disease lymphomas
Creator: Steep, Alexander Cordiner
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Meq, a bZIP transcription factor and the viral oncogene for pathogenic strains of Marek's disease virus (MDV), is required to induce CD4 T cell lymphomas that characterize Marek's disease (MD) in chickens. However, Meq is not sufficient for neoplastic transformation as not all birds infected with pathogenic strains of MDV developed Marek's disease. We hypothesize that additional drivers or somatic mutations in the chicken genome are required for MDV-induced transformation. Using and...
Show more"Meq, a bZIP transcription factor and the viral oncogene for pathogenic strains of Marek's disease virus (MDV), is required to induce CD4 T cell lymphomas that characterize Marek's disease (MD) in chickens. However, Meq is not sufficient for neoplastic transformation as not all birds infected with pathogenic strains of MDV developed Marek's disease. We hypothesize that additional drivers or somatic mutations in the chicken genome are required for MDV-induced transformation. Using and integrating DNA and RNA genomic screens of Marek's disease tumors from genetically-defined experimental layers, our analyses reveal 0.3 somatic mutations per megabase consisting primarily of somatic single nucleotide variants (SNVs) and small insertions and deletions (Indels). Somatic deletions, insertions, and point mutations were enriched in IKZF1 (Ikaros), the first driver gene of Marek's disease lymphomas. Ikaros, a Zn-finger transcription factor and the master regulator of lymphocyte development, is a known tumor suppressor in human and murine acute leukemias and lymphomas. In our surveyed Marek's disease tumors, 41% of the samples had somatic mutations in key N-terminal Zn-finger binding domains, strongly suggesting perturbed Ikaros function in its ability to bind DNA and regulate transcription. Somatic mutations in IKZF1 were preferentially found in tumors of gonadal tissues as well as their metastatic clones. IKZF1 mutant Marek's disease tumors revealed gene expression profiles indicative of Ikaros perturbation. In addition to IKZF1, other putative somatic mutations reside in ZNF384, EFNA5, CLDND1, FOXD1, ROBO1, and ROBO2 and warrant evaluation. Our results suggest MDV-induced tumors are driven by both Meq expression and IKZF1 somatic mutations that in combination lead to unregulated proliferation, increased cell adhesion, increased migration, and dedifferentiation."--Pages ii-iii.
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Title: A geometry based approach towards improving the structural integrity of single-walled ti6al4v alloy features fabricated using laser directed energy deposition additive manufacturing
Creator: Thakkar, Darshan
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Presence of sharp turns in the deposition tool-path for Additive Manufacturing (AM) introduces heterogeneity in built-part thereby affecting structural integrity. Slower deposition speeds around turn points or corner leads to defects such as increased wall thickness, porosity, lack of fusion voids, and cracks. Such defects can be minimized by either by optimizing processing parameters or through geometry optimization. Optimizing processing parameters requires extensive and expensive set of...
Show morePresence of sharp turns in the deposition tool-path for Additive Manufacturing (AM) introduces heterogeneity in built-part thereby affecting structural integrity. Slower deposition speeds around turn points or corner leads to defects such as increased wall thickness, porosity, lack of fusion voids, and cracks. Such defects can be minimized by either by optimizing processing parameters or through geometry optimization. Optimizing processing parameters requires extensive and expensive set of experiments. Furthermore, it is challenging to accurately model the process and have closed loop controls because of the impracticality to include all process parameters. This work focuses on optimizing the geometry instead of process parameters to fabricate components with minimum defects. In this work, single walled cubical Ti6Al4V shells with sharp and rounded corners were fabricated using laser Directed Energy Deposition (DED). Cross sectional and build plane coupons were extracted from each sample for microstructure and defect analysis. Results show that inclusion of rounded corners leads to consistent deposition speeds. Defect density measurements, using optical microscope, show reduction of defects from 6.8 ± 0.35% to a virtually defect-free structure for samples with rounded corners. Results indicate that consistent deposition speed around rounded corners improved homogeneity in the resulting microstructure.
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Title: A global modeling framework for plasma kinetics : development and applications
Creator: Parsey, Guy Morland
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The modern study of plasmas, and applications thereof, has developed synchronously with com-puter capabilities since the mid-1950s. Complexities inherent to these charged-particle, many-body, systems have resulted in the development of multiple simulation methods (particle-in-cell,fluid, global modeling, etc.) in order to both explain observed phenomena and predict outcomesof plasma applications. Recognizing that different algorithms are chosen to best address specifictopics of interest, this...
Show moreThe modern study of plasmas, and applications thereof, has developed synchronously with com-puter capabilities since the mid-1950s. Complexities inherent to these charged-particle, many-body, systems have resulted in the development of multiple simulation methods (particle-in-cell,fluid, global modeling, etc.) in order to both explain observed phenomena and predict outcomesof plasma applications. Recognizing that different algorithms are chosen to best address specifictopics of interest, this thesis centers around the development of an open-source global model frame-work for the focused study of non-equilibrium plasma kinetics. After verification and validationof the framework, it was used to study two physical phenomena: plasma-assisted combustion andthe recently proposed optically-pumped rare gas metastable laser.Global models permeate chemistry and plasma science, relying on spatial averaging to focusattention on the dynamics of reaction networks. Defined by a set of species continuity and energyconservation equations, the required data and constructed systems are conceptually similar acrossmost applications, providing a light platform for exploratory and result-search parameter scan-ning. Unfortunately, it is common practice for custom code to be developed for each application-an enormous duplication of effort which negatively affects the quality of the software produced.Presented herein, the Python-based Kinetic Global Modeling framework (KGMf) was designed tosupport all modeling phases: collection and analysis of reaction data, construction of an exportablesystem of model ODEs, and a platform for interactive evaluation and post-processing analysis. Asymbolic ODE system is constructed for interactive manipulation and generation of a Jacobian,both of which are compiled as operation-optimized C-code.Plasma-assisted combustion and ignition (PAC/PAI) embody the modernization of burning fuelby opening up new avenues of control and optimization. With applications ranging from engineefficiency and pollution control to stabilized operation of scramjet technology in hypersonic flows,developing an understanding of the underlying plasma chemistry is of the utmost importance.While the use of equilibrium (thermal) plasmas in the combustion process extends back to the ad-vent of the spark-ignition engine, works from the last few decades have demonstrated fundamentaldifferences between PAC and classical combustion theory. The KGMf is applied to nanosecond-discharge systems in order to analyze the effects of electron energy distribution assumptions onreaction kinetics and highlight the usefulness of 0D modeling in systems defined by coupled andcomplex physics.With fundamentally different principles involved, the concept of optically-pumped rare gasmetastable lasing (RGL) presents a novel opportunity for scalable high-powered lasers by takingadvantage of similarities in the electronic structure of elements while traversing the periodic ta-ble. Building from the proven concept of diode-pumped alkali vapor lasers (DPAL), RGL systemsdemonstrate remarkably similar spectral characteristics without problems associated with heatedcaustic vapors. First introduced in 2012, numerical studies on the latent kinetics remain immature.This work couples an analytic model developed for DPAL with KGMf plasma chemistry to bet-ter understand the interaction of a non-equilibrium plasma with the induced laser processes anddetermine if optical pumping could be avoided through careful discharge selection.
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Title: A livelihood and systems-based approach for understanding drivers of adoption and disadoption of organic farming in Ibadan, Nigeria
Creator: Adebiyi, Jelili Adegboyega
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Livelihood challenges such as low income, food insecurity, and poverty are prevalent among farming and rural communities in sub-Saharan Africa (SSA) and are linked to low agricultural productivity. Boosting agricultural productivity is considered pivotal to improving the livelihood conditions of farming and rural communities in SSA. Some non-governmental stakeholders and international development agencies promote organic agriculture as a pro-poor strategy to help enhance agricultural...
Show more"Livelihood challenges such as low income, food insecurity, and poverty are prevalent among farming and rural communities in sub-Saharan Africa (SSA) and are linked to low agricultural productivity. Boosting agricultural productivity is considered pivotal to improving the livelihood conditions of farming and rural communities in SSA. Some non-governmental stakeholders and international development agencies promote organic agriculture as a pro-poor strategy to help enhance agricultural productivity and farmers' livelihoods conditions in SSA. For reasons yet to be well-understood, the adoption rates of organic farming by smallholder farmers in SSA is low. To fill these gaps, in three essays, this dissertation investigated the barriers and the factors that influence and gender the adoption of first-party certified organic leafy vegetable production (OLVP) by smallholder farmers in Ibadan, southwestern Nigeria. First, we developed a gender-aware and livelihood-based conceptual framework named TALAF, which was used to inform the second and third essays. The first essay qualitatively examined the factors that influence, inhibit and gender the adoption of OLVP. The second essay investigated the factors and contexts that motivated disadoption of OLVP in the study areas in order to generate insights about what can be done to avert or stem the phenomenon. The third essay combined participatory causal loop diagraming with network analysis to map and contrast the similarities and differences in the causal mechanisms that dynamically interact to affect the adoption of organic farming in urban and rural Nigeria. As a whole, the dissertation contributes to the literature on the adoption, disadoption and gendering of organic farming in Nigeria and Africa. Through TALAF, the dissertation offers a conceptual framework that can help untie the complexity in technology adoption decision-making contexts."--Page ii.
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Title: A meditation on loss within games
Creator: Tokarski, Justin C.
Date: 2016
Collection: Electronic Theses & Dissertations
Description: "Failure is something which we are all familiar with, but when we look at games and the rules which govern them failure takes on a different form. This kind of failure, unique to games, is what I term Loss. To be truly unique to games, Loss must be the result of gamic actions taken by the player, must be constrained by the limitations of the game, and must represent a unique occurrence or state within the game. Taking these constraints into account I propose the following as a definition of...
Show more"Failure is something which we are all familiar with, but when we look at games and the rules which govern them failure takes on a different form. This kind of failure, unique to games, is what I term Loss. To be truly unique to games, Loss must be the result of gamic actions taken by the player, must be constrained by the limitations of the game, and must represent a unique occurrence or state within the game. Taking these constraints into account I propose the following as a definition of Loss. Loss is a player state in a game, entered into when a 'Loss Condition' has been met by the direct actions of the player, wherein something valued by the player within the game is removed. This definition, upon inspection, leads to several different and unique aspects, or dimension, of Loss which provide useful tools for understanding, analyzing, and creating Loss within games. The Digital Dimension of Loss consists of the binary triggers, Loss Conditionals, which lead the game to enter a State of Loss. The Design Dimension of Loss is the method of translating Loss Conditionals into unique game events understandable to the player. The Value Dimension of Loss consists of the gamic measures of effort that are taken away from the player by Loss. Finally, the Experience Dimension of Loss concerns the subjective effects of Loss on the player and methods for predicting what these effects will be. Together, this definition and the 4 aspects of Loss provide us new tools for understanding Loss as unique to games and distinct from failure in non-game contexts."--Page ii.
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Title: A minimalistic data distribution system to support uncertainty-aware GIS
Creator: Ronnei, Nicholas Oren
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Error and uncertainty are inherent in all digital elevation models (DEMs) - representations of the Earth's terrain. It is absolutely essential to account for this uncertainty in any GIS operations that rely on this data because uncertainty propagates through any derived products. This can have very serious consequences such as the potential invalidation of model results. Geostatistical methods like conditional stochastic simulation have been developed to mitigate this problem, but they...
Show moreError and uncertainty are inherent in all digital elevation models (DEMs) - representations of the Earth's terrain. It is absolutely essential to account for this uncertainty in any GIS operations that rely on this data because uncertainty propagates through any derived products. This can have very serious consequences such as the potential invalidation of model results. Geostatistical methods like conditional stochastic simulation have been developed to mitigate this problem, but they require expert knowledge to apply them to a project. Despite the fact that uncertainty propagation has been discussed in geographic literature for nearly three decades, there has been very little progress in making such analysis accessible to those who are not geostatistics experts--the majority of GIS users. This research uses open source software to build a system that makes the results of complex error models accessible to researchers worldwide without the need for expert knowledge. Then, I use this system to acquire data and perform a basic analysis, demonstrating how the average researcher might incorporate uncertainty propagation in own their work. In doing so, I hope to elucidate the ways in which conditional stochastic simulation changes the traditional spatial data model and set an example for others to follow. -- Abstract.
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Title: A mixed-method study of friendship networks and psychological and sociocultural adaptation among chinese international undergraduates in u.s. higher education
Creator: Xie, Mingjun
Date: 2019
Collection: Electronic Theses & Dissertations
Description: In recent years, U.S. colleges and universities have observed a rapid expansion of the enrollment of international students. Particularly Chinese students, the largest group of international students since 2010, have increased nearly threefold in just eight years (Institute of International Education, 2010-2018). Prior studies have investigated the friendship networks of international students (Rose-Redwood & Rose-Redwood, 2013) and the influence of peer relations on international students'...
Show moreIn recent years, U.S. colleges and universities have observed a rapid expansion of the enrollment of international students. Particularly Chinese students, the largest group of international students since 2010, have increased nearly threefold in just eight years (Institute of International Education, 2010-2018). Prior studies have investigated the friendship networks of international students (Rose-Redwood & Rose-Redwood, 2013) and the influence of peer relations on international students' cross-cultural adaptation (Hendrickson, Rosen, & Aune, 2011). However, the extant literature has largely neglected to examine international students' lived experiences of establishing friendship networks and the underlying mechanism of the associations between friendships and international student adaptation. Guided by social capital theory (Lin, 1999) and acculturation process framework (Ward, Bochner, & Furnham, 2001), the purpose of my dissertation is to examine Chinese students' peer interaction patterns and how friendships influence their psychological well-being and sociocultural adjustment.My dissertation consists of two studies. The first study drew upon two waves of surveys collected with 46 Chinese students (30 females, Mage = 18.89, SD = .80) and multiple in-depth interviews conducted with five students (three females, Mage = 18.40, SD = .89). The results yield three main findings. First, Chinese students of the present study nominated predominant Chinese friends, much more than domestic and other international student friends, in both waves. Second, Chinese students did not necessarily develop more diverse, integrated friendship networks over time. Specifically, more than half of the participants nominated Chinese friends only in both waves, possibly because of language barriers and prior discrimination experiences. Lastly, the interview findings illustrated that Chinese students' engagement in college settings shaped their experiences of building friendship networks, such that greater engagement in meaningful common experiences (such as club activities, religious groups, and experiences of working together) could facilitate cross-cultural interaction between Chinese students and domestic students.Guided by social capital theory (Lin, 1999) and acculturation process framework (Ward, Bochner, & Furnham, 2001), the second study examined: (1) how friendship networks, specifically the national backgrounds of nominated friends, the frequency of contact, and the intimacy of friendships, are associated with psychological and sociocultural adaptation among Chinese undergraduates (N = 273, Mage = 19.18, SD = .84) in U.S. higher education; and (2) the role of social connectedness as a mediator. Results indicated that compared to superficial relationships, high-quality peer interaction (for example, friendships involving both frequent contact and intimacy) might be a key to bolster Chinese students' ability to navigate cross-cultural challenges. Further, social connectedness mediated the associations between friendships and student adaptation, such that frequent and intimate interaction with domestic students was associated with greater social connectedness and, in turn, better psychological and sociocultural adaptation. The findings point to practical implications for the host institutions, especially for universities enrolling large numbers of international students. It is important for the host institutions to develop corresponding programs to facilitate social opportunities for different groups to mingle and establish sustained friendships.
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Title: A new paradigm for generating surface-normal forces for hull-cleaning robots
Creator: Kamensky, Kristina Maria
Date: 2020
Collection: Electronic Theses & Dissertations
Description: A Bernoulli pad uses an axial jet to produce radial outflow between the pad and a proximally located parallel surface, which may be either a mobile workpiece or a fixed wall. The flow field produces a force between the surfaces which depends upon their spacing h. The direction of this force is repulsive for large and small h, but two equilibria exist between these limits. The nearer equilibrium point (heq) is stable, and this distance is dependent on the direction and magnitude of the force...
Show moreA Bernoulli pad uses an axial jet to produce radial outflow between the pad and a proximally located parallel surface, which may be either a mobile workpiece or a fixed wall. The flow field produces a force between the surfaces which depends upon their spacing h. The direction of this force is repulsive for large and small h, but two equilibria exist between these limits. The nearer equilibrium point (heq) is stable, and this distance is dependent on the direction and magnitude of the force the pad is required to apply. Increasing the flow rate increases the strength of the contactless grip, subject to cavitation or compressibility constraints, depending on the working fluid. Industry has created devices of this type to grip and transport a variety of workpieces without contact. The present research is inspired by the need to keep a submerged ship hull free of biofouling organisms. Preventative maintenance during idle periods of operations can improve efficiency while prolonging the original surface properties of the hull. The Bernoulli pad for this application is significantly larger and uses the surrounding water as the working fluid. In the present work, the flow field was investigated computationally and experimentally. Field tests were also performed to determine the ability of the device to mitigate biofouling. The computational work, which was validated with experimental results found in literature, indicates that a power-law relationship exists between heq and the inlet fluid power required to sustain this equilibrium spacing when each is appropriately scaled. This scaling is derived principally from the wall shear; an additional term incorporating the inlet Reynolds number is used to account for the force applied to the system. The relationship is valid over a range of forces acting on the system, geometric, and material properties. Major and minor geometry alterations provide insight to customizing pressure or wall shear stress profiles.The biofouling removal ability of a shear-based device was field tested on two submerged surface types, Garolite G-10 and AkzoNobel's Intersleek 1100SR. The latter is a fouling-release coating. Each surface was groomed at four frequencies along with a control group during a seven-week grooming study conducted in Narragansett Bay in Rhode Island. An image-processing algorithm was developed and used to assess the effectiveness of the various grooming protocols, along with direct measurements of chlorophyll a per surface area. The image-processing data showed that the grooming resulted in approximately 50% cleanliness on the Garolite at the end of the study whereas the Intersleek was continuously restored to nearly its initial clean state. Chlorophyll a data supported these overall conclusions. These results indicate that surface cleanliness can be maintained effectively on Intersleek using frequent shear-based grooming. The key to success is to match or supersede the critical wall shear stress of settled biofouling organisms whose adhesive strength is exponential in time.Particle Tracking Velocimetry (PTV) measurements were also taken on the flow field. This Lagrangian measurement approach uses an iterative particle reconstruction technique in combination with high seeding density to reconstruct a 4D (x, y, z, t) flow field. This 4D reconstruction allows the pressure field to be reconstructed using the Navier-Stokes equations. Various experiments have been conducted on confined radial outflow but PTV measurements are presented here for the first time. The PTV measurements were compared with computational results and while there is reasonable agreement in the velocity field data, there are discrepancies is the pressure field data. Recommendations are provided for future work that can reconcile these differences.
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Title: A practical approach for ultra high performance concrete construction
Creator: Chen, Yang (Graduate of Michigan State University in civil engineering)
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Ultra-high-performance concrete (UHPC) with compressive strengths in excess of 150 MPa promise to enhance the structural efficiency and durability of concrete-based infrastructure systems. In order to transition UHPC materials into mainstream construction practices, there are needs to develop refined mix design procedures that enable production of UHPC using primarily locally available materials, resolves the problems with production of homogeneous UHPC mixtures using commonly available...
Show more"Ultra-high-performance concrete (UHPC) with compressive strengths in excess of 150 MPa promise to enhance the structural efficiency and durability of concrete-based infrastructure systems. In order to transition UHPC materials into mainstream construction practices, there are needs to develop refined mix design procedures that enable production of UHPC using primarily locally available materials, resolves the problems with production of homogeneous UHPC mixtures using commonly available concrete mixers, develop convenient fresh mix workability test methods that consider the peculiar rheology of fresh UHPC mixtures, and quantify some aspects of the UHPC material properties that have not been fully characterized. The UHPC materials were tested for fresh mix flow and hardened concrete compressive strength. The trends in the effects of packing density, water film thickness and excess paste film thickness on compressive strength and fresh mix flow were investigated. The results were used to identify viable ranges of these defining characteristics of UHPC mixtures. Response surface analysis of the fresh mix flow and the hardened concrete compressive strength test results led to identification of the optimum values of mix design parameters. The optimum mix was prepared, and was found to produce a highly desired balance of fresh mix flow and hardened concrete compressive strength, which occurred within the ranges predicted by response surface analysis of experimental results."--Page ii.
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Title: A return to brotherhood : nationalism, globalization and the negotiation of identity in Romani brass band music in Serbia
Creator: Kay, Matthew James
Date: 2019
Collection: Electronic Theses & Dissertations
Description: This thesis tells a story, or more accurately, many stories: The story of the Romani people who have been famed for their musicianship for centuries, but have also been despised and persecuted for their differences and lack of a singular homeland. It tells the story of Serbia; its trials and tribulations; a country keen to be known for its hospitality rather than its wars. There is also my story, and my family's story, the friendships that we made along the way, and how our lives were touched...
Show moreThis thesis tells a story, or more accurately, many stories: The story of the Romani people who have been famed for their musicianship for centuries, but have also been despised and persecuted for their differences and lack of a singular homeland. It tells the story of Serbia; its trials and tribulations; a country keen to be known for its hospitality rather than its wars. There is also my story, and my family's story, the friendships that we made along the way, and how our lives were touched by the Serbian people. There is also the deeper story of human experience through music. One only has to watch the news to feel cynical about the merits of human nature, but this thesis tells the story of a people who were not so long ago torn apart with war, xenophobia, and genocide, now welcoming outsiders and celebrating styles of music that they once sought to eliminate. This thesis will show how Romani brass bands bridged the divide between East and West, local and global, urban and rural, pure and ethnic, and how the Roma, a marginalized race of people, helped rebrand the Serbian identity.
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Title: A risk reduction approach to tsetse and African trypanosomiasis control : case study the canvas method
Creator: Jordan, Demetrice R.
Date: 2020
Collection: Electronic Theses & Dissertations
Description: African trypanosomiasis is an inherently multiscale human-animal-environment problem, with a spatially and environmentally constrained vector, a transnational disease distribution, two distinct disease strains (East and West African), innumerable human and animal reservoirs, and entrenched socio-cultural barriers and policy challenges. Colloquially known as 'sleeping sickness' and 'Nagana' in animals, African trypanosomiasis is a parasitic infection caused by pathogenic protozoa of the genus...
Show moreAfrican trypanosomiasis is an inherently multiscale human-animal-environment problem, with a spatially and environmentally constrained vector, a transnational disease distribution, two distinct disease strains (East and West African), innumerable human and animal reservoirs, and entrenched socio-cultural barriers and policy challenges. Colloquially known as 'sleeping sickness' and 'Nagana' in animals, African trypanosomiasis is a parasitic infection caused by pathogenic protozoa of the genus Trypanosoma. The parasite is transmitted through the salivary glands of tsetse fly during a blood meal. African trypanosomiasis is a major neglected tropical disease endemic to 36 countries in sub-Saharan Africa. Neglected tropical diseases are communicable, viral, parasitic, and bacterial infections that mainly affect poor people. Worldwide, neglected tropical diseases are not allotted the resources necessary to control and eradicate them. As a neglected tropical disease, African trypanosomiasis is given a lower global health priority which hinders control program effectiveness. Despite decades of research to control tsetse, trypanosomiasis continues to threaten the health and well-being of people and animals across sub-Saharan Africa. Compounded by resource constraints for control efforts, African trypanosomiasis is also poorly understood, severely underreported, often misdiagnosed, and fatal. The disease has a case fatality rate of nearly 100%, if untreated. While treatment is available, they are often expensive and toxic. Annual deaths attributed to African trypanosomiasis have a compounding impact across human and animal populations and the landscape. An estimated 60 million Africans and countless livestock are at risk of the infection, illuminating the need for risk reduction approaches to mitigate exposure. This dissertation examines tsetse and African trypanosomiasis control from an interdisciplinary perspective, combining health geography, disease ecology, diffusion of disease epidemiology, development economics, and global health policy. As a more general contribution, this dissertation presents a framework for addressing vector-host problems, using a multifaceted risk reduction and control strategy, innovative methodologies, and community participation to increase long-term success.
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Title: A social and biological evaluation of new zealand mudsnail invasion in michigan rivers
Creator: Tank, Samantha Nicole
Date: 2020
Collection: Electronic Theses & Dissertations
Description: New Zealand mudsnails (Potamopyrgus antipodarum; NZMS) are a small gastropod native to New Zealand and a documented worldwide invader. Michigan rivers are in the early phase of invasion, as NZMS were first detected in 2015 in the Pere Marquette River. In the early invasion process, information on likely vectors and the distribution of the species are critical to developing a well-informed management plan. My primary goals for this thesis were to address these informational needs. In order to...
Show moreNew Zealand mudsnails (Potamopyrgus antipodarum; NZMS) are a small gastropod native to New Zealand and a documented worldwide invader. Michigan rivers are in the early phase of invasion, as NZMS were first detected in 2015 in the Pere Marquette River. In the early invasion process, information on likely vectors and the distribution of the species are critical to developing a well-informed management plan. My primary goals for this thesis were to address these informational needs. In order to document the distribution of NZMS, I developed a sampling methodology and evaluated its effectiveness, as standard methods for lotic sampling NZMS have not been developed in the literature. I conducted a total of 227 surveys in 12 Michigan rivers between 2015 and 2018. Survey data were analyzed using an occupancy model, resulting in a per survey detectability exceeding 96%. NZMS were detected in 5 Michigan rivers: the Pere Marquette, Boardman, Manistee, Au Sable, and Pine rivers. I estimate that more than 65 river kilometers within the Pere Marquette, Boardman, and Pine rivers are infested. The distribution of NZMS suggests discrete transport events, and that the introduction into Michigan likely occurred well before the first reported detection of this species. The literature indicates that the wading gear of anglers is the main vector of transport within and between rivers. I surveyed 308 anglers fishing the Pere Marquette River in 2016-2017. Even though 52% of anglers were aware of NZMS, there was not a significant difference in wader cleaning behaviors between anglers aware or unaware of NZMS, indicating that outreach efforts need to focus beyond the awareness stage. As no in-stream method of treatment is presently available, angler engagement should be a focus of future management efforts.
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Title: A study on dam construction, hydrological changes, and the shift in dietary protein in the Lower Mekong River Basin
Creator: Burbano, Mateo
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "An important ramification that could be linked to the accelerated dam construction in the Lower Mekong Basin (LMB) is a dietary shift from fish as a source of protein to land-animal- based protein. The proposed chain of events that lead to this conclusion starts with a disruption in the river's hydrodynamics from dams (e.g., flood-pulse, annual discharge, seasonality, water level), combined with physical barrier (i.e., a dam structure) lead to lower fish catch rates and reproduction from...
Show more"An important ramification that could be linked to the accelerated dam construction in the Lower Mekong Basin (LMB) is a dietary shift from fish as a source of protein to land-animal- based protein. The proposed chain of events that lead to this conclusion starts with a disruption in the river's hydrodynamics from dams (e.g., flood-pulse, annual discharge, seasonality, water level), combined with physical barrier (i.e., a dam structure) lead to lower fish catch rates and reproduction from migratory impediment. A shift to a westernized diet by the developing country population of the LMB countries, can be observed as well. A relationship between fish catch and flooded area is developed to downscale fish catch to a 10 km grid in the study area, which enables the quantification of yearly distributed catch per capita. It is found that wet years yield higher catch per capita than dry years. Further, a statistical analysis on fish and meat production and consumption show an overall increase in local production of meat. The 2% cropland expansion is found to be largely attributed to an increase in meat production as most of the crops are grown for animal feed. Finally, a meat virtual water trade (VWT) network of is constructed between 1988 and 2016. Virtual water outflow is four to eight orders of magnitude larger than inflow from 1998 to 2003, when outflow drops significantly, and the direction of flow completely reverses. In fact, in 2011 the LMB countries' virtual water inflow reached similar values to that of past outflow (1998-2003). The abrupt virtual water flow change opens the door for a water savings analysis, where local and international production of meat is discussed to reach greater regional water savings (RWS) (i.e., minimizing water footprint)."--Page ii.
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Title: A systematic evaluation of computational models of phonotactics
Creator: Sarver, Isaac
Date: 2020
Collection: Electronic Theses & Dissertations
Description: In this thesis, recent computational models of phonotactics are discussed and evaluated and two new models are implemented. Prior phonotactic modeling, motivated by gradient acceptability judgments in nonce word judgment tasks (Albright 2009), claim that phonotactic grammaticality is gradient, and these models are evaluated by their ability to judge nonce words with scores that correlate with human acceptability judgments. Gorman (2013) argues that these gradient models do not account for the...
Show moreIn this thesis, recent computational models of phonotactics are discussed and evaluated and two new models are implemented. Prior phonotactic modeling, motivated by gradient acceptability judgments in nonce word judgment tasks (Albright 2009), claim that phonotactic grammaticality is gradient, and these models are evaluated by their ability to judge nonce words with scores that correlate with human acceptability judgments. Gorman (2013) argues that these gradient models do not account for the facts sufficiently and claims phonotactic grammaticality is categorical. In this thesis, the account of Gorman (2013) is implemented as well as a prominent gradient model from Hayes and Wilson (2008) and compared with the performance of two machine learning models (a support vector machine and a recurrent neural network), with all models trained on a corpus of English onsets. Results in this thesis show that the computational models are unable to correlate with human judgment data from Scholes (1966) as well as a categorical prediction of acceptability based on whether a sequence is attested in the lexicon or not, and that these models rely on assumptions which when challenged show that the models do not convincingly capture the gradience of the human judgment data used for evaluation.
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Title: A topological study of toroidal dynamics
Creator: Gakhar, Hitesh
Date: 2020
Collection: Electronic Theses & Dissertations
Description: This dissertation focuses on developing theoretical tools in the field of Topological Data Analysis and more specifically, in the study of toroidal dynamical systems. We make contributions to the development of persistent homology by proving Kunneth-type theorems, to topological time series analysis by further developing the theory of sliding window embeddings, and to multiscale data coordinatization in topological spaces by proving stability theorems. First, in classical algebraic topology,...
Show moreThis dissertation focuses on developing theoretical tools in the field of Topological Data Analysis and more specifically, in the study of toroidal dynamical systems. We make contributions to the development of persistent homology by proving Kunneth-type theorems, to topological time series analysis by further developing the theory of sliding window embeddings, and to multiscale data coordinatization in topological spaces by proving stability theorems. First, in classical algebraic topology, the Kunneth theorem relates the homology of two topological spaces with that of their product. We prove Kunneth theorems for the persistent homology of the categorical and tensor product of filtered spaces. That is, we describe the persistent homology of these product filtrations in terms of that of the filtered components. Using these theorems, we also develop novel methods for algorithmic and abstract computations of persistent homology. One of the direct applications of these results is the abstract computation of Rips persistent homology of the N-dimensional torus.Next, we develop the general theory of sliding window embeddings of quasiperiodic functions and their persistent homology. We show that the sliding window embeddings of quasiperiodic functions, under appropriate choices of the embedding dimension and time delay, are dense in higher dimensional tori. We also explicitly provide methods to choose these parameters. Furthermore, we prove lower bounds on Rips persistent homology of these embeddings. Using one of the persistent Kunneth formulae, we provide an alternate algorithm to compute the Rips persistent homology of the sliding window embedding, which outperforms the traditional methods of landmark sampling in both accuracy and time. We also apply our theory to music, where using sliding windows and persistent homology, we characterize dissonant sounds as quasiperiodic in nature.Finally, we prove stability results for sparse multiscale circular coordinates. These coordinates on a data set were first created to aid non-linear dimensionality reduction analysis. The algorithm identifies a significant integer persistent cohomology class in the Rips filtration on a landmark set and solves a linear least squares optimization problem to construct a circled valued function on the data set. However, these coordinates depend on the choice of the landmarks. We show that these coordinates are stable under Wasserstein noise on the landmark set.
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Title: A-stable implicit rapid scheme and software solution for electromagnetic wave propagation
Creator: Thavappiragsam, Mathialakan
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "A robust and rapid scheme to solve electromagnetics (EM) is an important requirement in the scientific computing environment in which there are several useful methods used to solve tasks in EM. Our research study is motivated by this need and is targeted to develop a fast A-stable implicit numerical scheme and scalable software solution for EM wave propagation. Our scheme is based on the Method Of Lines Transpose (MOLT) approach which discretizes time first and then solves boundary value...
Show more"A robust and rapid scheme to solve electromagnetics (EM) is an important requirement in the scientific computing environment in which there are several useful methods used to solve tasks in EM. Our research study is motivated by this need and is targeted to develop a fast A-stable implicit numerical scheme and scalable software solution for EM wave propagation. Our scheme is based on the Method Of Lines Transpose (MOLT) approach which discretizes time first and then solves boundary value problems. By applying the free-space Green's function, the solution is derived by decomposing particular and homogeneous solutions. The compact Simpson's quadrature based, O(N) fast convolution, a recursive algorithm, is used to solve the particular solution for N number of grid points. The homogeneous solution is obtained using a particular solution at the boundary points and the applied boundary conditions. The multi-dimensional scheme is developed using the ADI splitting approach and an arbitrary order accuracy in time is achieved by switching the time derivation to a spatial derivation using the Lax-Wendroff approach.The focus of the work in this thesis has been to overcome the limitations in Neumann and outflow boundary conditions to get high-order accuracy by using special treatments that deal with a choice of the interpolation, finite difference stencil, and the initial conditions. In addition, we have extended these ideas to construct perfectly electrically conducting boundary conditions in 2D for the MOLT.In addition to introducing higher-order boundary conditions, an embedded boundary method is employed to deal with complex geometries. As the method is A-stable, it does not suffer from small-time step limitations that are found in explicit finite difference time domain methods when using either embedded boundary or cut cell methods to capture geometry. Further, we are developing an open source code MOLTN (Method Of Lines Transpose, Nth order) which is intended to be a hardware-independent, scalable software tool, using multi-node MPI, multi-core OpenMP, and GPU CUDA implementation. As a test case of the method, we implement and study the A6 magnetron with our embedded boundary method using point sources inside of the domain. The eventual goal is to combine this method with a novel particle method for the simulations of plasma. The particle method would treat particles as point particles that generate fields that are tracked on the mesh. No density or current will be mapped to the mesh. The consistency and performance of the scheme are evaluated for EM wave propagation and scattering using different shaped objects including curved boundaries and the introduction of true point sources that demonstrate how we handle particles. Stable solutions result for a wide range of mesh sizes and potential to leverage novel computing architectures, such as GPU, have been demonstrated."--Pages ii-iii.
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