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Title: Porous titanium dioxide nanomaterials for photocatalytic and photovoltaic applications
Creator: Li, Yan (Graduate of Michigan State University)
Date: 2016
Collection: Electronic Theses & Dissertations
Description: "The huge demand for fossil fuels and the risks of the environmental crisis have spurred an interest in renewable energies. Using the clean and abundant solar energy, semiconductor photocatalysis and photovoltaics have evoked tremendous interest. Titanium dioxide (titania, TiO2) has been the focus of the research trend because of its excellent crystallinity, photoreactivity, chemical and thermal stability, and low cost. The research objective presented in this dissertation is to fabricate...
Show more"The huge demand for fossil fuels and the risks of the environmental crisis have spurred an interest in renewable energies. Using the clean and abundant solar energy, semiconductor photocatalysis and photovoltaics have evoked tremendous interest. Titanium dioxide (titania, TiO2) has been the focus of the research trend because of its excellent crystallinity, photoreactivity, chemical and thermal stability, and low cost. The research objective presented in this dissertation is to fabricate titania nanomaterials with tunable porosities, large surface area, unique morphologies, and enhanced capacities of adsorption, electron transport, diffusion, and then apply them in photocatalysis and photovoltaics. A modified non-hydrolytic sol-gel system with calcium carbonate templating was developed to create macro/micro/nano porous anatase titanium dioxide. The hydrolysis rate was lowered by chelating ligands of valeric acid for slow and sufficient precursor coating. CaCO3 was completely removed via acidification, resulting in titania powders with a surface area ranging from 197 to 239 m2/g. The templated TiO2 with a surface area of 239 m2/g and pore diameters of 6-109 nm showed a promising 27% photocatalytic improvement compared to commercial particles, and a 180% increase compared to template-free TiO2. This increase is attributed to the increased catalyst loading capacity and active photocatalytic sites. From hard templates to soft biodegradable natural templates, the rate-controlled sol-gel method was combined with homogenized micro/nano-fibrillated cellulose (MFCs) with an average diameter below 50 nm. Cellulose was removed completely by thermal treatment, and an in-situ coating technique created thin titania films on substrates with a porous structure. The degradation efficiency of the photocatalytic films was related to film thickness and to the Ti(IV)-to-cellulose ratio. Photocatalyst on film eliminated the post separation treatment related to powder catalyst and simplified the purification process. The sol-gel/MFCs precursor was also coated in-situ as the photoanode for dye-sensitized solar cells. It was found that the thickness of the anode film was a dominant factor to the overall performance and efficiency. The 6-layer cell showed a 400303% increase in solar-to-electricity efficiency (1.75%) compared to commercial paste at the same thickness under a simulated solar light irradiation of 100 mW cm-2 (AM 1.5). From non-hydrolytic to hydrolytic, a modified liquid phase deposition (LPD) approach was combined with MFCs. An optimized solvent composition of isopropanol/water ratio of 4 to 1 was found to yield coatings with uniform spherical TiO2 possessing a chain-like morphology oriented along the axis of the decomposed cellulose fibers. The average rate constant and degradation percentage were 0.72±0.09 min-1, 95% for TiF4-cellulose-4IPA1Water films, which increased by 1.88 times over the film prepared without cellulose templates due to the beneficial surface area, pore size, and the unique morphology. The three-dimensional web structure with pseudo one-dimensional sphere-chain could retard the recombination of photogenerated electron-hole pairs and improve the charge transport."--Pages ii-iii.
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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: Social-ecological systems, values, and the science of "people management"
Creator: Piso, Zachary Amedeo
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This dissertation interrogates a shift in environmental science, policy, and management toward conceptualizing the environment as a social-ecological system. Social-ecological systems science reflects an interdisciplinary effort to understand how individuals and communities achieve their environmental goals through the institutions that they maintain. Though the paradigmatic institutions concern economic behavior (e.g. property rights institutions), the field embraces the social sciences...
Show moreThis dissertation interrogates a shift in environmental science, policy, and management toward conceptualizing the environment as a social-ecological system. Social-ecological systems science reflects an interdisciplinary effort to understand how individuals and communities achieve their environmental goals through the institutions that they maintain. Though the paradigmatic institutions concern economic behavior (e.g. property rights institutions), the field embraces the social sciences broadly, with contributions from sociology, anthropology, geography, political science, and so on. That said, social science is fairly narrowly conceived; leaders in the field stress that they are studying social mechanisms in order to predict and manage social behavior. In a popular textbook on the subject, Fikret Berkes and Carl Folke stress that "resource management is people management" and call for a social science of this management.Social-ecological systems scientists have generally neglected the ethics of people management-for the most part they subscribe to a fairly typical fact/value dichotomy according to which scientists describe social-ecological systems while managers and policymakers prescribe actions in light of these descriptions. Following several philosophical traditions (in particular pragmatist philosophy of science), I call attention to the ways that social-ecological systems science is value-laden. I take environmental pragmatism to provide a roadmap for conducting social-ecological systems science ethically. Environmental pragmatists stress that science is always embedded in practical problem-solving activities that presuppose particular goals for, and side constraints to, inquiry. Many traditions in the philosophy of environmental science embrace social science for the specific role of facilitating this deliberation, but these traditions do not seem to anticipate the explanatory ambitions of social sciences. This leaves unaddressed several pertinent questions about how social explanations work (i.e. how functional distinction structure inquiry), which have very practical implications for which social science disciplines should be included in a collaboration and how social and ecological knowledge should be integrated. For example, most social situations are characterized by property rights institutions, cultural traditions, political alliances, and other social institutions within the purview of particular social science disciplines, but researchers are not reflexive about whether to explain environmental change according to one set of practices or another.The dissertation traverses the following terrain: the first chapter more carefully motivates the questions above regarding the need for ethics and the promise, but present inadequacy, of environmental pragmatism to meet this need. Chapter two attends to Dewey's theory of inquiry, in particular the dialogical dimension of inquiry that authorizes warranted assertions. Through reflection on Daniel Bromley's volitional pragmatism and a debate between Richard Rorty and hermeneutic social scientists, chapter three attends to the way that social science structures inquiry in order to intervene in the normative practices of a community. Chapter four analyzes social-ecological explanations in order to locate normative and evaluative assumptions that should be accountable to democratic deliberation. Finally, chapter five redescribes interdisciplinary integration as an ethical project where decisions about the centering and decentering of different sciences is as much ethical as epistemological.
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Title: The meaning of teaching mathematics : teacher positionings as embedded in algebra teachers' guides
Creator: Suh, Heejoo
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Teacher educators have been examining the professional status of teaching, including defining central practices of teaching, comparing teaching to other professions, and understanding teachers’ own perspective via interviews, surveys, and observations. The present study intends to contribute to the discussion by examining the meaning of teaching as reflected in teachers’ guides. I chose to examine teachers’ guides because they are known to have impact on teachers. Being a resource that is...
Show moreTeacher educators have been examining the professional status of teaching, including defining central practices of teaching, comparing teaching to other professions, and understanding teachers’ own perspective via interviews, surveys, and observations. The present study intends to contribute to the discussion by examining the meaning of teaching as reflected in teachers’ guides. I chose to examine teachers’ guides because they are known to have impact on teachers. Being a resource that is close to teachers’ everyday practices, curriculum materials inspire teachers with what they could do in their classroom. Educators intending large-scale educational reform pay attention to curriculum materials. Careful use of linguistic features therein could enhance thus further support teachers’ guides in effective communication with teachers.I investigated four 8 th grade Algebra teachers’ guides - TG, selectively chosen to represent variety. Drawing on positioning theory, I observed positionings regularly appearing in each of those four. Then I turned to idiosyncratically-observable positionings. Two research questions sought understanding of what teaching mathematics entails as presented in the TGs, hence how each guide constructs teaching mathematics. Last, I examined the guides’ linguistic features. This was for understanding the degree of teacher professional judgment acknowledged by the guides.My results indicated that, as constructed by each guide, teaching mathematics does not differ much across the guides. Those guides presented various types of knowledge as entailed in teaching mathematics. Compared to aspects on teacher professionalism in the literature, the guides occasionally addressed teacher research, interaction with colleagues, utilizing knowledge, and acknowledging uncertainty. In addressing these aspects, the guides in most cases did so with insufficient support. Examining idiosyncratic positionings, I found two types: i) positionings occurred idiosyncratic only, and ii) positionings occurred idiosyncratically in addition to their regular appearance. The latter can be classified into two types: a) one that succeeds the context of the communication actions associated with the general positioning, and b) one dissociated from the context. My linguistic examination of the guides suggested that they varied in their use of voice. Some are more directive, others are more suggestive, indicating different levels of acknowledgement of teachers’ professional judgment. In this dissertation’s last chapter, I present ways in which this study contributes to understanding of curriculum materials and of teacher professionalism. I end this dissertation with implications for curriculum authors, teachers, teacher educators, and researchers.
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Title: Solid-state nuclear magnetic resonance studies of the structures, membrane locations, cholesterol contact, and membrane motions of membrane-associated HIV Fusion Peptide (HFP
Creator: Jia, Lihui (Scientist)
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Membrane fusion is the key step during HIV viral entry to cells, and the process is catalyzed by HIV membrane fusion protein gp41. HFP is the ~25-residue N-terminal domain of gp41 and is required for membrane fusion with significant decreases in fusion activity with point mutations. Both viral and host cell membrane contain ~30mol % cholesterol (CHOL), and HFP induced fusion is faster in membrane with CHOL. However, how HFP interacts with membrane lipids and CHOL is unknown. In this thesis,...
Show moreMembrane fusion is the key step during HIV viral entry to cells, and the process is catalyzed by HIV membrane fusion protein gp41. HFP is the ~25-residue N-terminal domain of gp41 and is required for membrane fusion with significant decreases in fusion activity with point mutations. Both viral and host cell membrane contain ~30mol % cholesterol (CHOL), and HFP induced fusion is faster in membrane with CHOL. However, how HFP interacts with membrane lipids and CHOL is unknown. In this thesis, we used the newly developed 13C-2H Rotational Echo Double Resonance (REDOR) solid-state NMR method to study the membrane location of HFP in chemically-native membrane environment. HFP is 13CO labeled at specific residue, and the membrane is deuterated at specific regions of the membrane using selective regions deuterated phosphatidylcholine (PC) and CHOL. We study HFP wild type, HFP_V2E and L9R mutants because these two mutants eliminate and decrease fusion respectively. HFP is predominantly β sheet structure in bilayer membrane for both HFP wild type and HFP_V2E mutant, HFP_L9R has a different structure and is likely helical. Both HFP and HFP_V2E mutant have major deeply-inserted membrane location contacting membrane center and minor shallowly-inserted membrane location contacting half way of one membrane leaflet. The HFP_V2E mutant has bigger fraction of molecules with shallower membrane location, which is consistent with the strong correlation between membrane location insertion depth and the peptide fusogenicity. HFP_L9R mutant has majorly deeply inserted into membrane.By comparing the HFP- PC and HFP- CHOL contact, there is preferential contact between HFP and CHOL vs PC at several residues including G5, G10 and G16. The free energy difference for contacting PC vs CHOL is ~ 0.57(5) kcal.mol-1 for T= 300K. HFP- CHOL contact geometry is successfully modeled by Swiss Dock and YASARA energy minimization with two strands antiparallel HFP (1→16/16→1 registry). There are two energetically favorable binding models between HFP and CHOL, from docking, energy minimization and consistency with REDOR results. The contact models reveal tilted and curved-up tail orientation of Chol_d7. Fusion may be catalyzed by matching the curvature of lipids contacting HFPs with the membrane curvature during the fusion intermediates like the stalk. Membrane motion perturbation by HFP is studied by static deuterium NMR from deuterium powder pattern spectrum, order parameter profile and T2 relaxation time. The DMPC-d54 spectrum becomes ~10% narrower in membrane without CHOL with 4% HFP and in membrane with 33% CHOL with 1% HFP. Accordingly, the order parameter of lipid acyl chain becomes ~ 1-10% disordered by HFP. However, the spectrum becomes 20% broader in membrane with 33% CHOL with 4% HFP, and the order parameter of lipid acyl chain becomes ~ 20- 30% ordered by HFP. With HFP at 37 °C, DMPC-d54 T2 decreases ~ 70 %, and the CHOL T2 decreases ~ 30%. T2 reduction is probably associated with increased membrane curvature induced by HFP. With greater membrane curvature, the C-D bond will experience more orientation diversity relative to the external magnetic field. Thus, the quadrupolar field will have greater change, leading to faster relaxation and shorter T2. Gp41_V2E mutant eliminates cell-cell fusion. Our CD spectroscopy studies show that the FPHM_V2E mutant is helical and the melting temperature is above 90 °C in 10mM Tris buffer + 0.2 % SDS at pH 7.4. Protein is trimer and induces no lipid mixing in PC: CHOL= 2:1 vesicles.
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Title: Analyzing and reducing energy consumption on the Michigan State University campus
Creator: Renny, Alexander
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The reliance on fossil fuels to generate most of the world's energy has led to a significant increase in greenhouse gas emissions and the associated negative effects on the climate. The application of energy reducing retrofits allows for significant reductions in total energy use, providing the opportunity to achieve cost savings as well as emissions reductions. Students Planning Advanced Retrofit Technology Applications (SPARTA) was founded to pursue implementation of these retrofits at...
Show moreThe reliance on fossil fuels to generate most of the world's energy has led to a significant increase in greenhouse gas emissions and the associated negative effects on the climate. The application of energy reducing retrofits allows for significant reductions in total energy use, providing the opportunity to achieve cost savings as well as emissions reductions. Students Planning Advanced Retrofit Technology Applications (SPARTA) was founded to pursue implementation of these retrofits at Michigan State University (MSU). Under this framework, lighting, device, and HVAC retrofits are examined. In commercial spaces, lighting comprises 170303% of total electricity used. The economic viability of retrofitting LEDs in place of fluorescent ceiling fixtures as well as various control methods are determined. The energy use intensity of the average office space on the MSU campus is also analyzed and equipment changes are recommended to decrease the total energy footprint. Conversion from electricity driven cooling to steam driven cooling is evaluated as a method for increasing efficiency of the co-generation power plant and decreasing total fuel consumption. Finally, activities aimed at engaging the public on renewable energy generation are described, which are based on the development of paintable luminescent solar concentrators that combine art and energy. A number of techniques for reducing energy use on the MSU campus have been analyzed which can be applied across a broad spectrum of spaces. Continuing to aggressively pursue the implementation of this framework as well as tracking key economic indicators outlined will ultimately make MSU cleaner and more sustainable. -- Abstract.
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Title: Physics-based crystal plasticity modeling of single crystal niobium
Creator: Maiti, Tias
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Crystal plasticity models based on thermally activated dislocationkinetics has been successful in predicting the deformation behavior ofcrystalline materials, particularly in face-centered cubic (fcc) metals.In body-centered cubic (bcc) metals success has been limited owing toill-defined slip planes. The flow stress of a bcc metal is stronglydependent on temperature and orientation due to the non-planar splittingof a/2<111> screw dislocations. As a consequence of this, bccmetals show two...
Show moreCrystal plasticity models based on thermally activated dislocationkinetics has been successful in predicting the deformation behavior ofcrystalline materials, particularly in face-centered cubic (fcc) metals.In body-centered cubic (bcc) metals success has been limited owing toill-defined slip planes. The flow stress of a bcc metal is stronglydependent on temperature and orientation due to the non-planar splittingof a/2<111> screw dislocations. As a consequence of this, bccmetals show two unique deformation characteristics: (a) thermally-activated glide of screw dislocations - the motion of screwcomponents with their non-planar core structure at the atomistic leveloccurs even at low stress through the nucleation (assisted by thermalactivation) and lateral propagation of dislocation kink pairs; (b)break-down of the Schmid Law, where dislocation slip is driven only bythe resolved shear stress.Since the split dislocation core has to constrict for a kink pairformation (and propagation), the non-planarity of bcc screw dislocationcores entails an influence of (shear) stress components acting on planesother than the primary glide plane on their mobility. Anotherconsequence of the asymmetric core splitting on the glide plane is adirection-sensitive slip resistance, which is termed twinning/atwinningsense of shear and should be taken into account when developingconstitutive models.Modeling thermally-activated flow including the above-mentionednon-Schmid effects in bcc metals has been the subject of much work,starting in the 1980s and gaining increased interest in recent times.The majority of these works focus on single crystal deformation ofcommonly used metals such as Iron (Fe), Molybdenum (Mo), and Tungsten(W), while very few published studies address deformation behavior inNiobium (Nb). Most of the work on Nb revolves around fitting parametersof phenomenological descriptions, which do not capture adequately themacroscopic multi-stage hardening behavior and evolution ofcrystallographic texture from a physical point of view. Therefore, weaim to develop a physics-based crystal plasticity model that can capturethese effects as a function of grain orientations, microstructureparameters, and temperature.To achieve this goal, first, a new dilatational constitutive model isdeveloped for simulating the deformation of non-compact geometries (foamsor geometries with free surfaces) using the spectral method. The modelhas been used to mimic the void-growth behavior of a biaxially loadedplate with a circular inclusion. The results show that the proposedformulation provides a much better description of void-like behaviorcompared to the pure elastic behavior of voids. Using the developeddilatational framework, periodic boundary conditions arising from thespectral solver has been relaxed to study the tensile deformationbehavior of dogbone-shaped Nb single crystals.Second, a dislocation density-based constitutive model with storage andrecovery laws derived from Discrete Dislocation Dynamics (DDD) isimplemented to model multi-stage strain hardening. The influence ofpre-deformed dislocation content, dislocation interaction strengths andmean free path on stage II hardening is then simulated and compared within-situ tensile experiments.
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Title: Preservice teachers' intention to teach media and information literacy in their future classroom : an application of the theory of planned behavior
Creator: Gretter, Sarah
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "This dissertation is a multi-phase study looking at preservice teachers' intention to teach Media & Information Literacy in their future classroom. Each of the three studies presented in this dissertation answered a specific question: 1) What do preservice teachers think about teaching MIL? 2) What predicts preservice teachers' intention to teach MIL? and 3) How can we support preservice teachers' intention to teach MIL? The first paper in this dissertation reported on an elicitation study...
Show more"This dissertation is a multi-phase study looking at preservice teachers' intention to teach Media & Information Literacy in their future classroom. Each of the three studies presented in this dissertation answered a specific question: 1) What do preservice teachers think about teaching MIL? 2) What predicts preservice teachers' intention to teach MIL? and 3) How can we support preservice teachers' intention to teach MIL? The first paper in this dissertation reported on an elicitation study conducted with focus groups of preservice teachers to understand, from their perspectives, the factors that would either impede or facilitate the teaching of MIL in their future classroom. The second paper described the design, validation, and results of a survey based on these factors. The third paper reported on an online module with reflective exercises designed around the results gathered in the aforementioned survey. Each paper describes the findings that emerged from its study, followed by implications for research and practice, along with questions for the field of Media & Information Literacy education"--Page ii.
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Title: Where the rivers come together : reclaiming and re-imagining indigenous history, identity, and language in the city
Creator: Haviland, Adam
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The movement and migration of Native Americans to urban areas is usually traced to the urbanization programs of the 1950s and 1960s. However, the recent scholarship of Coll Thrush (2007) and John Low (2016) highlight the long history of urban spaces as Indigenous spaces and the role Indigenous people and communities have played in their growth and development. Similarly, the discourse of language loss and revitalization, urban spaces, and Indigenous urban communities are seen as places or...
Show moreThe movement and migration of Native Americans to urban areas is usually traced to the urbanization programs of the 1950s and 1960s. However, the recent scholarship of Coll Thrush (2007) and John Low (2016) highlight the long history of urban spaces as Indigenous spaces and the role Indigenous people and communities have played in their growth and development. Similarly, the discourse of language loss and revitalization, urban spaces, and Indigenous urban communities are seen as places or endpoints of assimilation. Thus, language revitalization efforts and programs often focus on reservations as the primary domains where Indigenous languages and their speakers persist and thrive. Yet, despite settler colonial narratives of vanishing that erase Indigenous people and Indigenous languages from urban areas, cities have, and continue to be, important intersections of movement and migration and with deep historical roots where Indigenous languages persist and thrive as ideological markers of identity, belonging, and as spoken languages.This Research shows how Lansing, Michigan, Nkwejong (the place where the rivers come together) has a long history as an Indigenous intersection and space that challenges the local settler-colonial narratives of removal and erasure. Lansing has remained an Indigenous space through traditions of movement and migration that were driven by the auto industry and educational opportunities. Through these movements, Anishinabek from reservations in and around Manitoulin Island came here in the 1960s and 1970s who were fluent speakers ofAnishinaabemowin. Anishinabek from Canada and local Anishinabek, who had lost the language, created community and belonging through educational programs. These spaces have become focal points where community comes together and, for many individuals, are the primary spaces where language, culture, and identity are reclaimed and passed on. However, these are also spaces of tension where gender roles, language ideologies, and linguistic practices concerning language as an ideological marker of identity and its role as a communicative system are challenged and reimagined.Through interviews with community members and participant observation, I explore relationships to urban and reservation “homelands,” the importance of education as places where individuals develop relationships to their identities and culture, and the role that language, as both an ideological marker of identity and belonging and as a communicative system, play in their everyday lives and experiences. While most participants agreed that language was important to preserving identity and traditional knowledge, their relationships with their identities as urban and Indigenous, and their relationships to Indigenous language, highlight: (1) the need to reexamine language ideologies that link Language to “traditional culture and Knowledge” and the impacts these ideologies have on language revitalization. (2) The importance of urban areas as Indigenous homelands and places where Indigenous languages persist, and (3) the role of education as intersections and places of tension where multiple ideologies, identities, and ways of being Indigenous are expressed and reimagined.
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Title: Feasibility and application of a CuxO-based memristor for sensing oxygen and other gases
Creator: Nyenke, Chinwe Pamela
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This dissertation introduces the design, fabrication, and application of acopper-oxide-based memristor for the passive sensing of oxygen and other gases.The device design was as follows: Deposition of copper (Cu) bottom electrodes,(oxygen) vacancy-rich copper oxide (CuxO) switching layers, and tungsten (W) topelectrodes in a crossbar array structure. The CuxO layer was deposited via reactivesputtering of a Cu target with an argon-oxygen (Ar/O2) mixture. A portion of thislayer was extended...
Show moreThis dissertation introduces the design, fabrication, and application of acopper-oxide-based memristor for the passive sensing of oxygen and other gases.The device design was as follows: Deposition of copper (Cu) bottom electrodes,(oxygen) vacancy-rich copper oxide (CuxO) switching layers, and tungsten (W) topelectrodes in a crossbar array structure. The CuxO layer was deposited via reactivesputtering of a Cu target with an argon-oxygen (Ar/O2) mixture. A portion of thislayer was extended from each array cell to be exposed for sensing. Memristivedevices of different switching layer thicknesses were initially explored forirreversible sensing of oxygen in ambient air. Results of this first experimentdemonstrated an increase in resistance states upon prolonged exposure toambient air. For the second experiment, memristive devices were fabricated withsub-micron holes that were etched into the W top electrode to better reveal theswitching layer surface. The devices were also subjected to ambient oxygen at 180deg C to induce passive sensing in minutes. Resistance results were consistentwith the first experiment but also revealed a dependence on the surface area ofthe exposed oxide. Finally, memristive devices were investigated in a thirdexperiment for reversible sensing of an oxidizing gas and reducing gas at roomtemperature. This time, changes were not only observed in resistance but also inhysteresis (current versus voltage) depending on the type of gas introduced.Overall, this work demonstrates a step towards the use of the memristor as a gassensor, which we have named “memsensors”, by taking advantage of the device’sability to memorize (or record) historical information.
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Title: Dynamic network analysis with applications to functional neural connectivity
Creator: Golibagh Mahyari, Arash
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Contemporary neuroimaging techniques provide neural activity recordings with increasing spatial and temporal resolution yielding rich multichannel datasets that can be exploited for detailed description of anatomical and functional connectivity patterns in the brain. Studies indicate that the changes in functional connectivity patterns across spatial and temporal scales play an important role in a wide range of cognitive and executive processes such as memory and attention as well as in the...
Show more"Contemporary neuroimaging techniques provide neural activity recordings with increasing spatial and temporal resolution yielding rich multichannel datasets that can be exploited for detailed description of anatomical and functional connectivity patterns in the brain. Studies indicate that the changes in functional connectivity patterns across spatial and temporal scales play an important role in a wide range of cognitive and executive processes such as memory and attention as well as in the understanding the causes of many neural diseases and psychopathologies such as epilepsy, Alzheimers, Parkinsons and schizophrenia. Early work in the area was limited to the analysis of static brain networks obtained through averaging long-term functional connectivity, thus neglecting possible time-varying connections. There is growing evidence that functional networks dynamically reorganize and coordinate on millisecond scale for the execution of mental processes. Functional networks consist of distinct network states, where each state is defined as a period of time during which the network topology is quasi-stationary. For this reason, there has been an interest in characterizing the dynamics of functional networks using high temporal resolution electroencephalogram recordings. In this thesis, dynamic functional connectivity networks are represented by multiway arrays, tensors, which are able to capture the complete topological structure of the networks. This thesis proposes new methods for both tracking the changes in these dynamic networks and characterizing or summarizing the network states. In order to achieve this goal, a Tucker decomposition based approach is introduced for detecting the change points for task-based electroencephalogram (EEG) functional connectivity networks through calculating the subspace distance between consecutive time steps. This is followed by a tensor-matrix projection based approach for summarizing multiple networks within a time interval. Tensor based summarization approaches do not necessarily result in sparse network and succinct states. Moreover, subspace based summarizations tend to capture the background brain activity more than the low energy sparse activations. For this reason, we propose utilizing the sparse common component and innovations (SCCI) model which simultaneously finds the sparse common component of multiple signals. However, as the number of signals in the model increases, this becomes computationally prohibitive. In this thesis, a hierarchical algorithm to recover the common component in the SCCI model is proposed for large number of signals. The hierarchical recovery of SCCI model solves the time and memory limitations at the expense of a slight decrease in the accuracy. This hierarchical model is used to separate the common and innovation components of functional connectivity networks across time. The innovation components are tracked over time to detect the change points, and the common component of the detected network states are used to obtain the network summarization. SCCI recovery algorithm finds the sparse representation of the common and innovation components of signals with respect to pre-determined dictionaries. However, input signals are not always well-represented by pre-determined dictionaries. In this thesis, a structured dictionary learning algorithm for SCCI model is developed. The proposed method is applied to EEG data collected during a study of error monitoring where two different types of brain responses are elicited in response to the stimulus. The learned dictionaries can discriminate between the response types and extract the error-related potentials (ERP) corresponding to the two responses."--Pages ii-iii.
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Title: Social influence on the Net : a mindset approach
Creator: Sah, Young June
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Social media afford a context within which users interact with other users. Recognizing variations in contexts afforded by social media, the current study classified social media into two types, i.e., relational media, which allow users to build individual social connections, and categorical media, which support group-based connections. Effects of relational and categorical media were examined, employing a mindset approach as a theoretical framework. The mindset approach manifests the...
Show moreSocial media afford a context within which users interact with other users. Recognizing variations in contexts afforded by social media, the current study classified social media into two types, i.e., relational media, which allow users to build individual social connections, and categorical media, which support group-based connections. Effects of relational and categorical media were examined, employing a mindset approach as a theoretical framework. The mindset approach manifests the situated nature of cognition, emphasizing individuals’ tendency to harness immediate contexts in meaning-making processing. Based on this postulation, the current study proposed that social media induced distinctive mindsets, entailing self-concept, goal-orientation, and concrete-abstract level in perceiving others.The current study also examined effects of social media on users’ group identification and belief change. Based on previous literature on social identity, it is proposed that distinctive mechanisms determine group identification in relational and categorical media. For relational media users, perception of individual relations to other users was expected to mediate the effect of relational media on group identification. In contrast, for categorical media users, perception of being a member of a group and perception of a homogeneous group were expected to mediate the effect of categorical media on group identification. Furthermore, based on the automatic social influence literature, the present study proposed that relational and categorical media, compared to non-social media, induce greater belief changes, and the belief changes are mediated by group identification. The predictions were tested using an online experiment (N = 705), in which participants used a mock-up social media, in which they formed social connections of either relational or categorical type, or used it without building social connection. Participants read others’ posts and comments revealing their opinions on health-related issues. Participants’ mindset, social perception, group identification, and belief changes were assessed. Results revealed that using social media influenced participants’ mindset: The relational group reported greater in-group self-concept and considered in-group goals more important, and used less concrete terms when describing their group members. Also, the categorical group considered in-group goals more important. Furthermore, using social media influenced group identification: The relational and categorical group reported greater group identification than the control group. Yet, the relative contributions of predictors of group identification differed across the conditions. For the relational media, relational perception was a dominant determinant of group identification and homogeneity perception was the least influential. For the categorical group, homogeneity perception was a predictor as significant as others. Lastly, effects of social media use on belief changes was not different across the social media type.The current study contributes to our understanding of how social media influence users by employing a novel theoretical framework, mindset approach, in examining subtle differences generated by social media. The mindset approach enables us to find nuanced effects: Different types of social media afford distinctive mindsets and psychological mechanisms for group identification.
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Title: Fluid animation on deforming surface meshes
Creator: Wang, Xiaojun (Graduate of Michigan State University)
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "We explore methods for visually plausible fluid simulation on deforming surfaces with inhomogeneous diffusion properties. While there are methods for fluid simulation on surfaces, not much research effort focused on the influence of the motion of underlying surface, in particular when it is not a rigid surface, such as knitted or woven textiles in motion. The complexity involved makes the simulation challenging to account for the non-inertial local frames typically used to describe the...
Show more"We explore methods for visually plausible fluid simulation on deforming surfaces with inhomogeneous diffusion properties. While there are methods for fluid simulation on surfaces, not much research effort focused on the influence of the motion of underlying surface, in particular when it is not a rigid surface, such as knitted or woven textiles in motion. The complexity involved makes the simulation challenging to account for the non-inertial local frames typically used to describe the motion and the anisotropic effects in diffusion, absorption, adsorption. Thus, our primary goal is to enable fast and stable method for such scenarios. First, in preparation of the material properties for the surface domain, we describe textiles with salient feature direction by bulk material property tensors in order to reduce the complexity, by employing 2D homogenization technique, which effectively turns microscale inhomogeneous properties into homogeneous properties in macroscale descriptions. We then use standard texture mapping techniques to map these tensors to triangles in the curved surface mesh, taking into account the alignment of each local tangent space with correct feature directions of the macroscale tensor. We show that this homogenization tool is intuitive, flexible and easily adjusted. Second, for efficient description of the deforming surface, we offer a new geometry representation for the surface with solely angles instead of vertex coordinates, to reduce storage for the motion of underlying surface. Since our simulation tool relies heavily on long sequences of 3D curved triangular meshes, it is worthwhile exploring such efficient representations to make our tool practical by reducing the memory access during real-time simulations as well as reducing the file sizes. Inspired by angle-based representations for tetrahedral meshes, we use spectral method to restore curved surface using both angles of the triangles and dihedral angles between adjacent triangles in the mesh. Moreover, in many surface deformation sequences, it is often sufficient to update the dihedral angles while keeping the triangle interior angles fixed. Third, we propose a framework for simulating various effects of fluid flowing on deforming surfaces. We directly applied our simulator on curved surface meshes instead of in parameter domains, whereas many existing simulation methods require a parameterization on the surface. We further demonstrate that fictitious forces induced by the surface motion can be added to the surface-based simulation at a small additional cost. These fictitious forces can be decomposed into different components. Only the rectilinear and Coriolis components are relevant to our choice of local frames. Other effects, such as diffusion, adsorption, absorption, and evaporation are also incorporated for realistic stain simulation. Finally, we explore the extraction of Lagrangian Coherent Structure (LCS), which is often referred to as the skeleton of fluid motion. The LCS structures are often described by ridges of the finite time Lyapunov exponent (FTLE) fields, which describe the extremal stretching of fluid parcels following the flow. We proposed a novel improvement to the ridge marching algorithm, which extract such ridges robustly for the typically noisy FTLE estimates even in well-defined fluid flows. Our results are potentially applicable to visualizing and controlling fluid trajectory patterns. In contrast to current methods for LCS calculation, which are only applicable to flat 2D or 3D domains and sensitive to noise, our ridge extraction is readily applicable to curved surfaces even when they are deforming. The collection of these computational tools will facilitate generation of realistic and easy to adjust surface fluid animation with various physically plausible effects on surface."--Pages ii-iii.
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Title: The limits of sympathy : professional philanthropy and detachment in narrative, 1869-1914
Creator: Beard, Erin Elizabeth
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The Limits of Sympathy intervenes in the scholarly conversation surrounding the relationship between philanthropic reform and the novel as well as the role of women in philanthropic work during late Victorian England. Importantly, this project brings archival texts, such as the philanthropic case reports of the Charity Organisation Society, into the conversation in order to demonstrate how the professionalization of philanthropy eliminated the role of sympathy in philanthropic work and...
Show moreThe Limits of Sympathy intervenes in the scholarly conversation surrounding the relationship between philanthropic reform and the novel as well as the role of women in philanthropic work during late Victorian England. Importantly, this project brings archival texts, such as the philanthropic case reports of the Charity Organisation Society, into the conversation in order to demonstrate how the professionalization of philanthropy eliminated the role of sympathy in philanthropic work and narrative. Where philanthropic texts created new narrative forms to grapple with the New Poor Laws and the changing urban environment of late Victorian London, novels by George Eliot, Walter Besant, H. G. Wells, Edith Johnstone, and Isabella Ford considered how the adoption of professionalized, distanced discourse affected women's perception of and participation in philanthropic work. These novels demonstrate how our current critical reliance on sympathy as a way to mediate the relationship between philanthropic and poor characters, as well as between reader and novel, no longer works within the context of professionalized philanthropy. -- Abstract.
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Title: Exploring the possibilities of Teachtown MKE : using local cultural institutions to support novice teachers' access to community resources
Creator: Shattuck, Tamara M.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Cultural institutions have the capacity to provide teachers with material resources for curriculum use in the classroom, professional support through connection to professional learning communities, promotion of self-confidence in teaching, and gains in subject content knowledge. There is building evidence that these types of support systems help novice teachers (i.e., teachers in their first three year of teaching), however many teachers do not have access to such support. And while access...
Show moreCultural institutions have the capacity to provide teachers with material resources for curriculum use in the classroom, professional support through connection to professional learning communities, promotion of self-confidence in teaching, and gains in subject content knowledge. There is building evidence that these types of support systems help novice teachers (i.e., teachers in their first three year of teaching), however many teachers do not have access to such support. And while access to resources is important for novice teachers, there is also evidence that access does not guarantee the use of resources. This descriptive study explores the inclusion of cultural institutions as partners in novice teacher support programs though the investigation of Milwaukee, Wisconsin's Key to the City Pass (KCP), which provides new teachers access to over 22 local cultural institutions. I also investigate how novice teachers develop and use the skill of relational agency -the ability to "work fluidly across professional boundaries" (Edwards, 2005a p. 177) and understand the utility of materials for problem solving. I hypothesize building the skill of relational agency helps novice teachers' better access KCP resources for professional use. Thus, four research questions drive this study; 1) How do teachers use KCP benefits? 2) Do teachers who participate in the KCP program incorporate community/cultural institution resources in their teaching practices, and if so how? 3) What barriers exist, and how can the KCP program be made more accessible for teachers? 4) Do participant teachers display the skill of relational agency, does this skill apply to KCP use? I used both quantitative and qualitative methods to analyze data and document teachers' use of the KCP through: (1) a teacher survey, (2) semi-structured focus group interviews, and (3) case study teacher interviews and artifact analysis. The quantitative survey data was analyzed first to gather general patterns of KCP use across participant teachers. I analyzed survey data using descriptive and inferential statistics. The qualitative data was analyzed in a second phase to gather information about how teachers use KCP resources. For the qualitative data analysis, I used deductive coding. Findings indicate that participants were mostly using the KCP program for personal reasons (e.g., trips with friends and family), and that they were able to connect with the local community through these trips. Through personal trips, teachers were also able to assess whether taking field trips to certain cultural institutions was appropriate for their students. Few teachers used the skill of relational agency in connection to the KCP and noted they were more likely to use cultural institution resources if they were clearly connected with state and district standards. Teachers were also more likely to use cultural institution resources if they had the opportunity to collaborate with cultural institution staff. This study enabled me to observe barriers to KCP use before generalizing how such a program might be created in other cities. Which in turn allowed me to understand the steps other cities should take in order to build stronger partnerships. Based on my findings of the barriers to KCP use I suggest cities who wish to form partnership programs: 1) gather input from all constituents, 2) create a strong mission statement, 3) connect to district wide initiatives, and 4) ensure a pathway for clear and continual communication between partners and participants.
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Title: Freshwater resources : an evaluation of Michigan residents' perception of wetland ecosystem services
Creator: Walkowiak, Toni Anne
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Thus, this research serves two purposes: (1), to gather information about Michigan residents' overall knowledge of wetlands ecosystems; (2), to establish whether residents can accurately distinguish between wetland functions and values. Two activities: semi-structured focus group interviews and online digital card sorts were conducted within Chippewa, Huron, and Macomb Counties of Michigan, to evaluate individuals' environmental perceptions of wetland ecosystems." -- Abstract.

Title: Affective aesthetics and the social politics of Neoliberalism in New Extremism cinema
Creator: Clark, Cameron
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This thesis investigates the aesthetics of transgression in New Extremism cinema for the ways in which they inform, and are mutually informed by, neoliberal affect and social politics. Although negative affect and spectatorial embodiment are often central to critical discourse on New Extremism, this thesis instead attends to the interlocking aesthetic, narrative, and spatio-temporal expressions of affect as they correlate with neoliberal politics of respectability and reproduction. By...
Show moreThis thesis investigates the aesthetics of transgression in New Extremism cinema for the ways in which they inform, and are mutually informed by, neoliberal affect and social politics. Although negative affect and spectatorial embodiment are often central to critical discourse on New Extremism, this thesis instead attends to the interlocking aesthetic, narrative, and spatio-temporal expressions of affect as they correlate with neoliberal politics of respectability and reproduction. By deploying feminism and queer theory, this thesis locates positive, productive potentials within formal expressions of negative affect that mobilize a political critique of the violences within each film. In so doing, the selected film examples--Fabrice Du Welz's Calvaire (2004), Marina de Van's Dans ma peu (2002), Olivier Assayas's Demonlover (2002), Bruno Dumont's Twentynine Palms (2004), François Ozon's Criminal Lovers (2001), Alain Guiraudie's Stranger by the Lake (2014), to name a few--portray the shifting relations between politics, gender, and sexuality in the neoliberal present and offer critical alternatives for how such developments have impacted and impeded sociality.
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Title: The political determinants of agricultural policy in sub-Saharan Africa
Creator: Lewis, Dominique Helena
Date: 2017
Collection: Electronic Theses & Dissertations
Description: My thesis investigates the political determinants of agricultural policy in sub-Saharan Africa, but my work also has implications for broader questions of development economics and public policy formation. Agricultural producers are vital engines of economic development in this region of the African continent. For this reason, policies that enhance the stability and growth of agricultural production are among the most crucial to development more generally. Yet across much of sub-Saharan...
Show moreMy thesis investigates the political determinants of agricultural policy in sub-Saharan Africa, but my work also has implications for broader questions of development economics and public policy formation. Agricultural producers are vital engines of economic development in this region of the African continent. For this reason, policies that enhance the stability and growth of agricultural production are among the most crucial to development more generally. Yet across much of sub-Saharan Africa, pricing policies often work to disadvantage agricultural production, while governmental spending on agricultural research and development remains low. Even more puzzling is the fact that rural constituents uniformly support incumbent policy makers at higher rates than their urban counterparts, even in the face of policies that are manifestly antithetical to their interests. The answer to this puzzle lies in the importance of collective action to policy creation and change and, in particular, how institutional constraints and other such barriers to collective action shape representation in the agricultural sector. Utilizing both the cross-country and temporal variation in policy environments and outputs, I show that institutional contexts which facilitate collective action are associated with pro-agricultural policies, including lower taxes on agricultural products and higher national-level spending on agricultural R&D. Such contexts -- which include institutional protections for civil liberties and higher levels of electoral competition -- allow marginalized groups such as the rural poor to mobilize more effectively, which in turn result in policies more favorable to their interests. Such policies are further facilitated by sector-specific features and practices which enhance mobilization, typically by decreasing the associated costs of such actions. My findings underscore the importance of the broader political and institutional forms on agricultural policy. That is to say, my analysis demonstrates that prescriptions and suggestions for reforms that are designed to enhance agricultural development should not and cannot be limited to those with agriculture as their sole and central focus.
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Title: Protease-containing membranes for rapid, controlled antibody digestion prior to mass spectrometry analysis
Creator: Pang, Yongle
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Monoclonal antibodies are the fastest growing class of therapeutic drugs because of their high specificities to targeQt cells. Facile analysis of therapeutic mAbs and their post-translational modifications (PTMs) is essential for quality control, and mass spectrometry (MS) is the most powerful tool for antibody characterization. Conventional antibody characterization workflows contain an in-solution digestion step, which is labor-intensive and time-consuming. Protease-containing membranes...
Show more"Monoclonal antibodies are the fastest growing class of therapeutic drugs because of their high specificities to targeQt cells. Facile analysis of therapeutic mAbs and their post-translational modifications (PTMs) is essential for quality control, and mass spectrometry (MS) is the most powerful tool for antibody characterization. Conventional antibody characterization workflows contain an in-solution digestion step, which is labor-intensive and time-consuming. Protease-containing membranes are an attractive alternative platform for protein digestion because of their high local enzyme concentrations, short radial diffusion distances, rapid convection in pores, simple fabrication and low cost. Additionally, variation of protein residence time in the membrane gives control over the size of proteolytic peptides. This research focuses on developing workflows for monoclonal antibody characterization using functionalized porous membranes. Sequential adsorption of poly (styrene sulfonate) and pepsin in a porous nylon membrane forms a pepsin membrane reactor. Pepsin is inexpensive and catalyzes proteolysis in acidic solutions, which avoids the need to alkylate cysteine residues and limits antibody deamidation. Variation of the residence times (3 ms to 3 s) of antibody solutions in pepsin-containing membranes yields "bottom-up" (1-2 kDa) to 'middle-down' (5-15 kDa) peptides in less than 10 min. These peptic peptides cover the entire sequences of Herceptin and a WatersTM antibody. Compared with the performance of bottom-up (in-solution tryptic digestion) and top-down (intact protein fragmentation) analysis of an antibody light chain, middle-down (in-membrane peptic digestion) analysis gives the highest bond cleavage (99%). In-membrane digestion also facilitates detection of PTMs such as oxidation, deamidation, N-terminal pyroglutamic acid formation and glycosylation. Recently developed protease-containing spin membranes provide an excellent platform for rapid, membrane-based protein digestion prior to ultrahigh-resolution Orbitrap MS analysis. Centrifugation of 100-200 æL of pretreated protein solutions through the pepsin- or trypsin-containing membranes takes less than 1 min and gives nearly 100% coverage of the protein sequences in subsequent direct infusion MS analysis of digests of apomyoglobin and four commercial monoclonal antibodies (Herceptin, Avastin, Rituxan and Vectibix). MS analysis of peptic and tryptic peptides also reveals mAb PTMs such as N-terminal pyroglutamate formation, C-terminal Lysine clipping and glycosylation. Liquid chromatography coupled to tandem mass spectrometry analysis of tryptic spin digests and subsequent MaxQuant data searching show 100% sequence coverage of all four antibody light chains, and 75.1%-98.4% coverage of the heavy chains. Compared to in-solution tryptic digestion of mAbs, spin digestion yields higher sequence coverage and a larger number of unique peptides. In-membrane digestion also facilitates protein sequence comparison. Rapid peptic in-membrane digestion of two antibodies with direct infusion MS analysis accurately reveals the antibody modification site in less than 1 h. Overall, membrane-based protein digestion uses minimal sample preparation time and yields high peptide and sequence coverages for identification of protein PTMs."--Page ii-iii.
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Title: Ultrafast transient states in nonequilibrium quantum systems
Creator: Hwang, Bin
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Photo-induced phase transitions (PIPT) in quantum systems are the epitome of challenging non-equilibrium many-body phenomena, that also have a wide range of potential applications. Recently interest in light-matter coupled states with an energy gap have yielded evidence for Floquet topological states. In this study we demonstrate nonequilibrium Floquet band formation under ultrafast optical excitation using a one-dimensional topological insulator. As an example, the effects are illustrated...
Show morePhoto-induced phase transitions (PIPT) in quantum systems are the epitome of challenging non-equilibrium many-body phenomena, that also have a wide range of potential applications. Recently interest in light-matter coupled states with an energy gap have yielded evidence for Floquet topological states. In this study we demonstrate nonequilibrium Floquet band formation under ultrafast optical excitation using a one-dimensional topological insulator. As an example, the effects are illustrated using a new Zig-Zag Su-Schrieffer-Heeger model of polyacetylene, which is a paradigmatic Hamiltonian exhibiting nontrivial edge states. Our results indicate short optical pulses feasible in experiments can induce novel topological states, local spectral selection and novel pseudospin textures in polyacetylene. Pump-probe photoemission spectroscopy is able to study these states by measuring Floquet band formation and sizeable energy gaps on femtosecond time scales. We find that optically activated nontrivial variations of sublattice mixing could lead to novel topological phenomenon.The rich variety of states induced by lasers have a wide range of potential applications so that control of these states has become a key objective. We present a computational approach to finding optimal ultrafast laser pulse shapes to induce target states and population inversion in pump-probe PIPT experiments. The Krotov approach for Quantum optimal control theory (QOCT) is combined with a Keldysh Green’s function calculation to describe experimental outcomes such as photoemission, transient single particle density of states and optical responses. Results for a simple model charge density wave (CDW) system are presented, including generation of almost complete population inversion and negative temperature states.
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