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2017

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Optimized Command Shaping With Constrained Peak Input Acceleration For Minimizing Residual Vibration, Bowen Wu Dec 2017

Optimized Command Shaping With Constrained Peak Input Acceleration For Minimizing Residual Vibration, Bowen Wu

Open Access Theses

The fast point-to-point motion of a robotic system can be greatly affected by its joint flexibilities, which introduce vibrations during and after motion. While numerous techniques were developed to minimize the residual vibration of the flexible robotic system, this work studies the command shaping method. This method constructs an input profile that aims to reduce excitation energy around the natural frequencies to minimize residual vibration. This work modifies the command shaping method by applying a numerical optimization technique with a constraint on peak input acceleration. A framework has been constructed for the combination of these two modifications, which proved their …

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Turning A Multivalent Lens Toward Depictions Of Artificial Intelligence (Ai) In Film, Ashley Ann Albrecht Dec 2017

Turning A Multivalent Lens Toward Depictions Of Artificial Intelligence (Ai) In Film, Ashley Ann Albrecht

Open Access Dissertations

With innovations in the field of artificial intelligence (AI) advancing at an exponential rate, it is ever the more pertinent to interrogate the ramifications and potentialities of these developments. Luciano Floridi, known as “the Google philosopher,” considers this phenomenon an integral part of the digital information age or the “Fourth Revolution.” We are now forced to confront the following problems: What is the relationship between humans and AI? What does it mean to be “human”? What futures are possible given our current coevolution with AI? Such questions motivate close philosophical consideration. Here, the theoretical polarization of the doomsday neo-Luddite versus …

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Investigation Of Noise And Vibration In Tires Through Analytical Modeling, Tests And Simulations, Rui Cao Dec 2017

Investigation Of Noise And Vibration In Tires Through Analytical Modeling, Tests And Simulations, Rui Cao

Open Access Dissertations

Tire noise and vibration is an interesting topic, with more and more people paying attention to this issue. Tire noise can both propagate into the vehicle interior and radiate directly toward the immediate environment. Tire noise is not only related to vehicle passengers’ comfort but also affects the residential or working area near highways, especially in high population density regions. The emerging electric vehicles also emphasize tires’ role in vehicle Noise Vibration and Harshness (NVH) since power-train noises are significantly reduced. The study in this research focuses on the noise and vibration of tires from the low to high frequency …

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Variability Of Persistent Temporal Correlation In Climate Data, Matthew C. Bowers Dec 2017

Variability Of Persistent Temporal Correlation In Climate Data, Matthew C. Bowers

Open Access Dissertations

This dissertation examines manifestations of persistent memory in climate data. Persistence is characterized by a slow power-law decay in the autocorrelations of a time series. Its existence implies that the influence of past values in a time series extend into the distant future. It has numerous theoretical implications, notably that it changes the asymptotic decay in the variance of sample means, which can substantially impact the uncertainty in climate mean states. Its intensity can vary over space, time, and other dimensions, e.g. tree species. Variation in its intensity can be used for practical applications such as discriminating between steady and …

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Optothermal Energy Conversion And Transport In Plasmonic Structures, Chen Chen Dec 2017

Optothermal Energy Conversion And Transport In Plasmonic Structures, Chen Chen

Open Access Dissertations

Plasmonic structures can efficiently interact with electromagnetic waves at their interfaces, leading to strong light confinement and field enhancement, which has been crucial for many nanotechnology applications in manufacturing, lithography, data storage, biosensing, spectroscopy, molecular trapping and other molecular level studies. Due to the intrinsic losses of metallic structures, the strong light-matter interaction also generates significant energy dissipation, making the thermal management of the devices very challenging. The purpose of this dissertation is to study the optothermal energy conversion and transport in plasmonic structures, especially in structures at the nanoscale. We first investigate the general optothermal responses of plasmonic structures …

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Learning Electron Transport Chain Process In Photosynthesis Using Video And Serious Game, Cecilia Espinoza Morales Dec 2017

Learning Electron Transport Chain Process In Photosynthesis Using Video And Serious Game, Cecilia Espinoza Morales

Open Access Dissertations

This research investigates students' learning about the electron transport chain (ETC) process in photosynthesis by watching a video followed by playing a serious board game-Electron Chute- that models the ETC process. To accomplish this goal, several learning outcomes regarding the misconceptions students' hold about photosynthesis and the ETC process in photosynthesis were defined. Middle school students need opportunities to develop cohesive models that explain the mechanistic processes of biological systems to support their learning. A six-week curriculum on photosynthesis included a one day learning activity using an ETC video and the Electron Chute game to model the ETC process. The …

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A New Method For Determining Hamaker Constants Of Solids Based On The Dynamic Approach Behavior Of An Atomic Force Microscope, Sean G. Fronczak Dec 2017

A New Method For Determining Hamaker Constants Of Solids Based On The Dynamic Approach Behavior Of An Atomic Force Microscope, Sean G. Fronczak

Open Access Dissertations

The Hamaker constant, A, is a very important parameter used to quantify the strength of the van der Waals (vdW) attractive interaction among particles and between particles and surfaces. Consequently, an accurate measurement of A is of fundamental importance to a wide range of research and manufacturing fields. Therefore, this dissertation primarily focuses on the development and application of a new method to determine Hamaker constants of solid materials using an atomic force microscope (AFM). While the direct contact or pull-off method is typically employed during an AFM force measurement, this contact-technique is highly dependent upon material properties that are …

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A Supervised Learning Approach For Dynamic Sampling (Slads), Gunawath Mudiyanselage Dilshan Prasanjana Godaliyadda Dec 2017

A Supervised Learning Approach For Dynamic Sampling (Slads), Gunawath Mudiyanselage Dilshan Prasanjana Godaliyadda

Open Access Dissertations

Sparse sampling schemes can broadly be classified in to two main categories: static sampling where the sampling pattern is predetermined, and dynamic sampling where each new measurement location is selected based on information obtained from previous measurements. Dynamic sampling methods are particularly appropriate for point-wise imaging methods in which pixels are measured sequentially in arbitrary order. Examples of point-wise imaging schemes include certain implementations of atomic force microscopy (AFM), electron back scatter diffraction (EBSD), and Scanning Electron Microscopy (SEM). In these point-wise imaging applications, dynamic sparse sampling methods have the potential to dramatically reduce the number of measurements required to …

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An Optimization-Based Approach To Determine Requirements And Aircraft Design Under Multi-Domain Uncertainties, Parithi Govindaraju Dec 2017

An Optimization-Based Approach To Determine Requirements And Aircraft Design Under Multi-Domain Uncertainties, Parithi Govindaraju

Open Access Dissertations

Determining the optimal requirements for and design variable values of new systems, which operate along with existing systems to provide a set of overarching capabilities, as a single task is challenging due to the highly interconnected effects that setting requirements on a new system’s design can have on how an operator uses this newly designed system. This task of determining the requirements and the design variable values becomes even more difficult because of the presence of uncertainties in the new system design and in the operational environment. This research proposed and investigated aspects of a framework that generates optimum design …

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Computational Modelling Of Thermal Transport Using Spectral Phonon Boltzmann Transport Equation, Ahmed Osama Ibrahim Hamed Dec 2017

Computational Modelling Of Thermal Transport Using Spectral Phonon Boltzmann Transport Equation, Ahmed Osama Ibrahim Hamed

Open Access Dissertations

Lattice vibration is the main microscopic mechanism for thermal transport in dielectric materials. The convenience of the analysis of atomic vibrations in the reciprocal space, motivated by the pioneering work of Debye and Peirels, made phonon transport theory is one of the standard paradigms adequate to study the microstructure and stoichiometry effects on thermal transport phenomena at mesoscale. UO2 is of theoretical as well as technological importance. The characteristic thermal transport phenomena at short length-scale (~ nanometer) and time-scale (~ picosecond) associated with radiation dictate close examination of available theoretical models and solution methods for thermal conductivity prediction, in addition …

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Cultivating Asian Students' Willingness To Communicate In American Classrooms Using An Online Video-Based Pre-Arrival Course, Hui-Ching Kayla Hsu Dec 2017

Cultivating Asian Students' Willingness To Communicate In American Classrooms Using An Online Video-Based Pre-Arrival Course, Hui-Ching Kayla Hsu

Open Access Dissertations

The purpose of this mixed methods study was: 1) to document the design and implementation process of an online video-based pre-arrival course that was intended to cultivate Asian students’ willingness to communicate in American Classrooms; 2) to assess the effectiveness of the course by measuring students’ oral proficiency and willingness to communicate; and 3) to investigate their first-year classroom participation as well as their experiences with the pre-arrival course. This research inquiry was guided by two research questions: 1) How does completing an online pre-arrival course influence Asian students’ speaking abilities, willingness to communicate, and verbal participation in their first-year …

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Design And Statistical Analysis Of Mass Spectrometry Imaging Experiments, April Janae Harry Dec 2017

Design And Statistical Analysis Of Mass Spectrometry Imaging Experiments, April Janae Harry

Open Access Dissertations

The goal of mass spectrometry-based imaging (MSI) is to characterize the chemical composition of biological samples such as tissues in spatial resolution, and changes in the composition between conditions such as the status of a disease. A single mass spectrometry image is a collection of mass spectra at gridded locations on a tissue. When acquired over multiple biological individuals, tissues, and conditions, the resulting datasets are tremendously complex in both scale and in the stochastic structure of the quantified spectral features. Accurate characterization of the biological and technical variation in these experiments is therefore key for deriving sensitive and reproducible …

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Rheological Behavior And Manufacturing Simulation Of Prepreg Platelet Molding Systems, Anthony J. Favaloro Dec 2017

Rheological Behavior And Manufacturing Simulation Of Prepreg Platelet Molding Systems, Anthony J. Favaloro

Open Access Dissertations

Molding systems formed by cutting and slitting prepreg composite tape into the form of platelets have been shown to be beneficial in producing parts with moderate performance with moderate processing characteristics. However, the platelets forming the molding system are typically quite large compared to typical part thicknesses. Therefore, a challenge of scales exists in platelet molding systems that is absent in traditionally considered well dispersed fiber molding systems used in injection molding. In this dissertation, we consider the specific problem of determining the final orientation state of parts manufactured in compression molding from platelet molding systems along with identifying parameters …

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Investigating The Conversations That Occur During Undergraduate Research Experiences: A Case Study, Sara L. Johnson Dec 2017

Investigating The Conversations That Occur During Undergraduate Research Experiences: A Case Study, Sara L. Johnson

Open Access Dissertations

Despite the increasing popularity of undergraduate research experiences across disciplines, little information currently exists to guide the design, evaluation, and improvement of these experiences. One challenge to generating such guidelines is the lack of evidence related to the processes and contexts in which undergraduate research experiences occur. My study sought to address this deficiency by exploring the norms of discourse that framed conversations between students and their mentors in biochemistry research as a model to understand the phenomenon of undergraduate research. I used a case-study approach to investigate the conversations that occurred between three student-mentor pairs as they engaged in …

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Household Decision Making Under Stress: Three Essays On Agricultural Production In Southern Africa, Anna Leigh Josephson Dec 2017

Household Decision Making Under Stress: Three Essays On Agricultural Production In Southern Africa, Anna Leigh Josephson

Open Access Dissertations

Rural households in Southern Africa face numerous economic challenges, arising from a range of idiosyncratic and covariate risks. This research seeks to understand strategies employed by households to cope with different types of shocks, in the context of Zimbabwe and Malawi. I focus on several techniques used to cope with risk and shocks in an uncertain environment, including intra-household resource, land, and crop, as well as labor allocations. To provide insight on household decision making, I expand and adapt theoretical models. This helps me to better understand household decision making in the complex and risky environments in which they reside …

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Investigating The Crystallization Propensity Of Structurally Similar Organic Molecules From Amorphous State, Arjun Kalra Dec 2017

Investigating The Crystallization Propensity Of Structurally Similar Organic Molecules From Amorphous State, Arjun Kalra

Open Access Dissertations

Combinatorial chemistry and high-throughput screening approaches utilized during drug discovery have resulted in many potent pharmacologically active molecules with low aqueous solubility and consequently poor bioavailability. Enabling technologies, such as amorphous solid dispersions (ASD’s), can obviate these challenges and provide an efficient route to formulate the drug as an oral solid dosage form. However, high-energy amorphous materials have an inherent tendency to crystallize and in doing so can negate the apparent solubility advantage achieved by using such formulations. Crystallization can occur during (1) cooling the drug molecule from the melt state (such as during hot melt extrusion); (2) during storage …

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Hyperspectral Image Reconstruction From Rgb Data And Its Biomedical Applications, Tae Hoon Kim Dec 2017

Hyperspectral Image Reconstruction From Rgb Data And Its Biomedical Applications, Tae Hoon Kim

Open Access Dissertations

Noninvasive label-free hyperspectral imaging of physiological changes in biological systems has been extensively used as invaluable tools in a variety of research areas, including medical and biological applications. However, conventional approach requires a critical, yet bulky, expensive, and slow optical component (i.e. a mechanical filter wheel, an imaging spectrograph, or a liquid crystal tunable filter) for capturing full spectral information. Therefore, this component limits development of compact, rapid, and cost-effective systems. In this respect, we propose to explore a possibility of spectrometerless (or spectrometer-free) hyperspectral imaging to map out detailed spatial distributions of biochemical absorption compounds or pigments, which are …

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Exploring Transformative Learning Pedagogies To Teach Human-Centered Design: A Collaborative Action Research Approach, Cole Hatfield Joslyn Dec 2017

Exploring Transformative Learning Pedagogies To Teach Human-Centered Design: A Collaborative Action Research Approach, Cole Hatfield Joslyn

Open Access Dissertations

In this research, I present the problem that a culture of disengagement endemic in engineering and engineering education (see Cech, 2014) is exacerbated by deeply rooted habits of mind and their underlying assumptions that are at odds with social justice ideals and resistant to change, thus, perpetuating the status quo (see Riley, 2008). Furthermore, current engineering education curricula focusing primarily on mathematics, science, and engineering sciences (see Sheppard, Macatangay, Colby, & Sullivan, 2009) further entrench this culture along with these habits of mind and assumptions. In an attempt to address the culture of disengagement, I propose a framework for humanizing …

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Engineering Play: Exploring Associations With Executive Function, Mathematical Ability, And Spatial Ability In Preschool, Zachary Samuel Gold Dec 2017

Engineering Play: Exploring Associations With Executive Function, Mathematical Ability, And Spatial Ability In Preschool, Zachary Samuel Gold

Open Access Dissertations

Engineering play is a new perspective on preschool education that views constructive play as an engineering design process that parallels the way engineers think and work when they develop engineered solutions to human problems (Bairaktarova, Evangelou, Bagiati, & Brophy, 2011). Early research from this perspective supports its use in framing play as a key learning context. However, no research to date has examined associations between engineering play and other factors linked with early school success, such as executive function, mathematical ability, and spatial ability. Additionally, more research is needed to further validate a new engineering play observational measure. This study …

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Imaging Cholesterol Metabolism And Trafficking By Stimulated Raman Scattering Microscopy, Hyeon Jeong Lee Dec 2017

Imaging Cholesterol Metabolism And Trafficking By Stimulated Raman Scattering Microscopy, Hyeon Jeong Lee

Open Access Dissertations

Cholesterol is an essential component of mammalian cells which is tightly regulated. However, our understanding of cholesterol transport and metabolism is still incomplete, partly due to lack of suitable tools for studying cholesterol dynamics in living cells and organisms with spatio-temporal information. My dissertation work applied spectroscopic imaging of cholesterol in human tissues, living cells, and model organisms to unravel new insights of cholesterol metabolism and trafficking. Using stimulated Raman spectroscopic analysis of lipid droplets in human prostate cancer patient tissues, we observed an aberrant accumulation of cholesteryl ester in metastatic lesions. Inhibition of cholesterol esterification in prostate cancer cells …

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Global Optimization Of Large-Scale Complex Nonlinear Systems: Algorithms And Applications, Jianfeng Liu Dec 2017

Global Optimization Of Large-Scale Complex Nonlinear Systems: Algorithms And Applications, Jianfeng Liu

Open Access Dissertations

Many practical applications involving large complex systems are naturally formulated as mixed-integer nonlinear programming (MINLP) problems. These optimization problems are inherently large-scale and non-convex, and can be extremely difficult to solve. Efficient algorithms, especially global solution strategies, for MINLP problems play important roles in many real-world applications. Although a number of optimization tools have been developed for general MINLP problems, their performance may vary significantly on different problem instances. Moreover, computational experience has suggested that for MINLP problems with certain particular properties, customized algorithms can significantly outperform general MINLP solvers. In this thesis, we focus on developing and applying problem-specific …

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A Study Of Singularities In Drops And Bubbles Under The Influence Of Non- Newtonian Surface And Bulk Rheology, Pritish M. Kamat Dec 2017

A Study Of Singularities In Drops And Bubbles Under The Influence Of Non- Newtonian Surface And Bulk Rheology, Pritish M. Kamat

Open Access Dissertations

Fluid-fluid interfaces are incredibly complex physical structures. Imbued with an excess energy—or in mechanical terms, a surface tension σ—these interfaces are considerably influential at small scales of droplets and bubbles, and in these systems, they are responsible for a plethora of beautiful and dramatically complex phenomena. The study of these interfacial phenomena, the so-called ‘free surface flows’, lends itself to a variety of applications which are at once, as mundane as liquid dripping from a faucet or rain splashing over the windscreen of a car, and at the same time extremely useful in industry and scientific analysis – some examples …

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Developing And Testing A K-12 Engineering Epistemic Frame To Uncover Engineering In The Interactions Of A High School Summer Session, Tamecia Raishuan Jones Dec 2017

Developing And Testing A K-12 Engineering Epistemic Frame To Uncover Engineering In The Interactions Of A High School Summer Session, Tamecia Raishuan Jones

Open Access Dissertations

Educational reform has expanded K-12 standards to include engineering. Not only will K-12 teachers have to be trained to teach engineering concepts, but assessments must evolve to reflect the various aspects of engineering. Engineering as a profession is expressed via multiple dimensions of an epistemic frame, such as skills, knowledge, identity, values, and epistemology, but many of these elements are not measured in K-12 formal and informal spaces. In a summer session of a college preparatory program, a research project revealed that although students had design journals, storyboards, and traditional assessments, the in situ video recordings captured decisions, evolution of …

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Wavetda: Bayesian Statistics, Wavelets And Topological Data Analysis To Title Assess Statistical Shape, Patrick S. Medina Dec 2017

Wavetda: Bayesian Statistics, Wavelets And Topological Data Analysis To Title Assess Statistical Shape, Patrick S. Medina

Open Access Dissertations

Advanced imaging and scanning technologies are providing an abundance of shape-based data that require novel approaches to understand the factors that generate them. This is especially true in modern agricultural practices where large quantities of highly detailed morphometric data are collected and used for studying genetic associations. Toward this end there is an immediate need for efficient algorithms that extract relevant geometric information from images in a form that can be used within a statistical framework. Topological Data Analysis (TDA) has shown to be both fast and effective for studying complex shapes, and can simultaneously reduce dimensionality into simpler topological …

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Teachers' Perceptions Of The Impact Of Culturally Responsive Pedagogy On The Student Learning Outcomes Of African American Male Students., Dennisha M. Murff Dec 2017

Teachers' Perceptions Of The Impact Of Culturally Responsive Pedagogy On The Student Learning Outcomes Of African American Male Students., Dennisha M. Murff

Open Access Dissertations

The purpose of this qualitative study was to explore teachers’ perceptions of the impact of implementing culturally responsive pedagogical practices on the student learning outcomes of African-American male students. The secondary purpose was to identify teachers’ perceptions of the culturally responsive pedagogy strategies needed in the classroom to address the diverse needs of African-American male students. The case study approach allowed for additional insight into the potential impact of culturally responsive pedagogical practices on the student learning outcomes of African-American male students in the elementary school setting. Data were collected from a large, diverse elementary school in an urban school …

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Investigation Of Pore Formation In Lipid Bilayer By Antimicrobial Peptides, Yuan Lyu Dec 2017

Investigation Of Pore Formation In Lipid Bilayer By Antimicrobial Peptides, Yuan Lyu

Open Access Dissertations

As more and more microbes develop resistance to conventional antibiotics and the decline in the approval of new antibiotics in recent years, there is an increasing need for research on identification and design of new therapeutic alternatives. As a result, antimicrobial peptides (AMPs) are becoming one of the most promising alternative options to target pathogens without developing resistance. It is known that AMPs inactivate microorganisms by forming transmembrane pores in cell membrane through adsorption and aggregation. Understanding the detailed mechanism of inactivation by AMPs is necessary for developing new agent for antimicrobial treatment. This study mainly investigates antimicrobial peptides from …

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Geophysical Signatures Of Fracture Mechanisms, Anahita Modiriasari Dec 2017

Geophysical Signatures Of Fracture Mechanisms, Anahita Modiriasari

Open Access Dissertations

Fractures and discontinuities have a significant influence on the mechanical and hydraulic properties of brittle materials such as rock. The prediction of rock mass behavior requires information on the location and character of the initiation, propagation, and coalescence of new and pre-existing cracks. Methods based on the interpretation of seismic waves are of great interest because the waves can be used to probe internal damage in rock. The objective of this research is to characterize crack initiation, propagation, and coalescence inside rock using wave propagation. Digital image correlation (DIC) was employed to investigate crack evolution on the surface of rock …

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Experimental Demonstration Of Engineered Dipole-Dipole Interactions In Nanophotonic Environments, Ward D. Newman Dec 2017

Experimental Demonstration Of Engineered Dipole-Dipole Interactions In Nanophotonic Environments, Ward D. Newman

Open Access Dissertations

Zero point fluctuations of the electromagnetic radiation field have profound effects on the electronic states of atoms and molecules. For example, vacuum fluctuations of the photonic radiation field stimulate the spontaneous decay of excited states of atoms (spontaneous emission), shift atomic energy levels (Lamb Shift), and allow nearby atoms and molecules to couple via dipole-dipole interactions (van der Waals interactions, Casimir effect, super radiance, F¨orster resonance energy transfer). The control and modification of vacuum fluctuations has been a long-standing theme in quantum engineering as one can then truly control single photon emission and alter dipole-dipole interactions spatial scaling with distance. …

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Carbon Taxes, Forest Carbon Sequestration, Climate Induced Land Yield Changes, And Their Interactions, Luis Moisés Peña-Lévano Dec 2017

Carbon Taxes, Forest Carbon Sequestration, Climate Induced Land Yield Changes, And Their Interactions, Luis Moisés Peña-Lévano

Open Access Dissertations

This dissertation is comprised of three essays that evaluate the economic benefits and costs of mitigating climate change at the global scale. Each essay relies on computable general equilibrium (CGE) modeling. The first essay evaluates the economic and environmental interactions among climate change, agriculture, forest carbon sequestration and food security. It addresses changes in land use, commodity and food prices, economic welfare, emission reductions, among other economic factors. This study finds that an aggressive sequestration subsidy can represent a threat for food security due to the land competition between agriculture and forestry. Likewise, the results suggest that there are benefits …

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Laser-Assisted Processing Of Multilayer Films For Inexpensive And Flexible Biomedical Microsystems, Rahim Rahimi Dec 2017

Laser-Assisted Processing Of Multilayer Films For Inexpensive And Flexible Biomedical Microsystems, Rahim Rahimi

Open Access Dissertations

Flexible/stretchable electronics offer ideal properties for emerging health monitoring devices that can seamlessly integrate with the soft, curvilinear, and dynamic surfaces of the human body. The resulting capabilities have allowed novel devices for monitoring physiological parameters, improving surgical procedures, and human-machine interfaces. While the attractiveness of these devices are indubitable, their fabrication by conventional cleanroom techniques makes them expensive and incompatible with rapid large-scale (e.g., roll-to-roll) production. The purpose of this research is to develop inexpensive fabrication technologies using low-cost commercial films such as polyimide, paper, and metalized paper that can be utilized for developing various flexible/stretchable physical and chemical …

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