Doctoral Dissertations (Winter 2014 to Present)

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New submissions to the University of Delaware Doctoral Dissertations collection are added as they are released by the Office of Graduate & Professional Education. The Office of Graduate & Professional Education deposits all dissertations from a given semester after the official graduation date.

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Skin assessment in primary care: skin cancer & people of color
(University of Delaware, 0202) Boyd, Sheavone D.
Problem and Purpose: This project examined the risk for people of color to have increased morbidity and mortality secondary to skin cancer despite its lower incidence in this population, how that correlates to late detection, and what implications exist. Skin assessment is a quick, easy and feasible examination that can lead to the early detection of skin lesions suspicious for cancer and has the potential to improve clinical outcomes. Despite being the key to early detection of skin cancer, comprehensive skin examination remains an extremely overlooked aspect of primary care. This practice change project aimed to increase the rate of total body skin assessment in primary care and promote referral to dermatology when indicated to improve early detection. ☐ Methods: Participants (n= 114) received total body skin examinations, as part of their annual wellness visit, by a nurse practitioner at a robust primary care office in Wilmington, Delaware. By way of chart reviews, the findings of these assessments were collected and analyzed to determine patient demographics, whether there was a patient-reported skin concern, whether suspicious lesions were detected, and if a referral to dermatology was made when indicated. ☐ Results: As a result of this practice change project there was an 83% increase in skin assessment. Additional results found that two patients required further treatment and/or referral, and 66% of the patients with positive skin assessments did not report a skin abnormality in their chief complaints, and thus, would not have received the skin assessment that led to a diagnosis that required treatment, per usual practice. There was also a 100% increase in the delivery of culturally sensitive patient education regarding skin cancer prevention and detection. ☐ Conclusion: This project has identified a gap in care that can easily be addressed. While lesions suspicious for skin cancer were not found as a result of this project, it remains clear that comprehensive skin assessment is, often, a missed opportunity to provide preventive care. ☐ Keywords: “total body skin exam,” “skin cancer,” “primary care,” “early detection"
The effect of gait retraining on external loading and associated bony loading in runners
(University of Delaware, 2011) Fellin, Rebecca Elizabeth
In the United States alone, approximately 16.4 million people participate in running activities. Unfortunately, up to 79% of these runners are injured each year. One more serious type of injury runners sustain is a tibial stress fracture, which is an injury that requires 6-8 weeks of rest. These injuries also have an alarmingly high 36% re-injury rate. Excessive vertical loading, such as load rates and tibial shock, has been linked to an increased risk of tibial stress fractures. Many runners exhibit excessive vertical loading bilaterally. Furthermore, torsional loading, quantified by the free moment, has been also implicated in tibial stress fracture development. Although both of these risk factors involve external loading, stress fractures occur due to loading at the bony level. Gait retraining to decrease vertical loading has been effective at decreasing these loads on the trained limb that received feedback. However, the impact of gait retraining on other risk factors such as free moment, contralateral limb loading, and the bony loading along the entire region where stress fractures are most common is unknown. Therefore, this dissertation consisted of three aims to examine changes following gait retraining with respect to each of these areas. ☐ The purpose of Aim 1 was to identify if runners who have high vertical and torsional loads can decrease those torsional loads through gait retraining to decrease vertical loading. We hypothesized that runners would decrease those loads following gait retraining. We further hypothesized that the decrease in torsional loading would be less than the decrease in vertical loading as the subjects were not receiving feedback on torsional loads. We collected data on twenty runners both pre and post gait retraining during overground running at 3.7 m/s. The gait retraining protocol consisted of eight sessions of real-time visual feedback during treadmill running at a self-selected speed. This feedback was from an accelerometer attached to the anterior-medial aspect of the subject's tibia on their limb with higher loads. The results revealed that runners with high peak adduction free moments reduce this peak following gait retraining. The decrease in free moment was moderately correlated to the decrease in vertical loading. Furthermore, the subjects decreased their free moment to a lesser degree than their vertical loading. ☐ The purpose of Aim 2 was to identify if reductions in vertical loading on the trained limb transfer to the contralateral, untrained limb. We hypothesized that runners would decrease vertical load rates and tibial shock on their trained and untrained, contralateral limb following gait retraining. We collected data on ten runners both pre and post gait retraining during treadmill running at 3.35 m/s and a self-selected speed. The gait retraining protocol consisted of eight sessions of real-time visual feedback during treadmill running at a self-selected speed. This feedback was from an accelerometer attached to the anterior-medial aspect of the subject's tibia on their limb with higher loads. Runners significantly decreased vertical load rates and tibial shock following gait retraining on both limbs and both running speeds. ☐ The purpose of Aim 3 was to identify if runners with high vertical loading decrease tibial strain rates from the midshaft to distal third following gait retraining. We hypothesized that runners would decrease tibial strain rates following gait retraining. Furthermore, we hypothesized that these tibial strain rate decreases would be proportional to the subject's external, vertical loading decreases. We collected data on five runners both pre and post gait retraining during overground running at 3.7 m/s. The gait retraining protocol consisted of eight sessions of real-time visual feedback during treadmill running at a self-selected speed. This feedback was from an accelerometer attached to the anterior-medial aspect of the subject's tibia on their limb with higher loads. The results were mixed as only 4/5 subjects demonstrated decreased tibial strain rates following gait retraining. These external loading decreases were similar in magnitude to the strain rate decreases for 2/5 subjects. Additional subjects should be studied to further validate these findings.
Not so obscure a challenge: battered female migrants and public policies in the United States and Greece
(University of Delaware, 2011) Wasileski, Gabriela
Immigration is becoming an increasingly important policy concern both in the U.S. and Greece, and also in many other nations. Importantly, there is an ever-growing number of women who migrate, many of whom are undocumented. Violence against immigrant women is nearly impossible to estimate. However, immigrant women who are abused face multiple barriers to seeking legal protection from the abuse as a result of their migration status. In many cases, immigrant women are unaware of the protection afforded to noncitizens, or the legal protection is limited so they may fear deportation from being exposed as noncitizens or fear the loss of custody of their children. Those immigrants who entered the country through a family reunion program are awarded derivative immigration status, so they can join their spouses in the United States. Consequently, a battered immigrant's ability to obtain or maintain lawful immigration status may depend on her relationship to her United States citizen or lawful permanent resident spouse and his willingness to file an immigrant relative petition on her behalf. ☐ Despite the increase in female migration, there is a paucity of research on gender issues within regularization and family programs. This study sheds light on how the migration status of battered immigrant women affects their options for seeking a remedy from interpersonal violence. Moreover, this research highlights how migration policies in Greece and the United States interfere with social and legal protection of undocumented immigrant battered women.
Reading matter: animals, vegetables, and media in Renaissance England
(University of Delaware, 2012) Calhoun, Joshua
Reading Matter explores the poetic interplay of words and matter in sixteenth- and seventeenth- century English texts. Made of recycled clothes, slaughtered animals, and felled trees, books in Renaissance England were filled with visible traces of ecological matter. Reading Matter demonstrates that the flora and fauna from which a text was made were legible, significant elements of its poetic form. Attending to the ecologies of writing and reading in sixteenth- and seventeenth-century England, this dissertation seeks to first recover and then to read those organic elements of Renaissance texts that both inflect meaning and indicate much about the intertwined acts of poesis and textual production in Renaissance England. I consider how plant fibers in the pages of printed and written texts were legible to Renaissance readers, how animals became illegible or invisible in paper even as their boiled down body parts allowed readers to make themselves legible in the margins of their printed books, how blots on a page make legible that which one might wish to obliterate, and how trees might be read, misread, and ventriloquized on the stage of the wooden Globe theater. ☐ More broadly, by studying the negotiations between poetics and ecology in Renaissance texts and by drawing on critical approaches such as material culture studies, book history, and historical formalism, Reading Matter seeks to outline a scholarly reading strategy that attends to the natural history of books, to both the function and the form of the organic matter used to mediate human ideas. Though focused on Renaissance texts, the project offers a methodology by which others might interrogate the textual ecologies of millennia-old Eastern palm leaf books, eighteenth-century Japanese texts, post-colonial Caribbean texts, or the latest iPad.
A life less valuable? Adjudication and sentencing outcomes for perpetrators of child homicide.
(University of Delaware, 2013) Poteyeva, Margarita
Killing a child almost universally galvanizes great outrage among the public. Despite this condemnation, little is known about how and if this abhorrence of killing a child translates into criminal justice practices. The purpose of this dissertation is to advance our understanding about the imposition of the law in cases of child homicide using a mixed-method design. The two general research objectives of the current study are: (1) to explore whether there are any differentials in the application of the law (e.g. decisions to prosecute, probability of conviction for offenders, and sentences received) for those who kill children compared to those who kill older victims; (2) to gain insight into the moral gradation of child homicide by exploring whether certain types of child homicide or certain perpetrators of the crime are treated more harshly than others. ☐ Quantitative analysis of a nationally representative data collected from prosecutors' offices in 33 large urban counties revealed that while killing a child did not have any effect on the probability of conviction, those who killed children received significantly shorter sentences than those who killed older victims. Being a mother-offender exuded a significant influence over the sentencing decision of the courts. ☐ Thematic and qualitative content analyses of data from the State of Maryland showed that the majority of death eligible cases with child victims either originated in a romantic conflict or involved a sexual assault on the child. No definitive conclusions could be drawn about the criteria that state attorneys in Maryland considered in determining whether or not to seek capital punishment in a particular child homicide case. In fact, there were several instances where legally similar crimes and offenders received different treatment. No female defendant in the Maryland sample was tried capitally, including the two women who were mothers to their victims. Contrasting these cases with female child homicide perpetrators who were sentenced to the death penalty in other states, however, suggests that prosecutors need to overcome a number of challenges to successfully portray female defendants as death-worthy.
Improving the spatial, angular, and temporal resolution in light field imaging
(University of Delaware, 2013) Yu, Zhan
A light field captures a dense set of rays as scene descriptions in place of geometry. Recent advances on computational imaging have enabled novel and efficient light field acquisition devices. For example, the new Lytro and Raytrix cameras are able to capture light fields in a single shot. However, the effective spatial resolution is reduced by the number of microlenses. For example, in Lytro, the resulting image at a desired focal plane has a resolution of 1080x1080, which is too low for photographic uses or in computer vision tasks. The acquired light field also has a low angular resolution, usually less than 10x10 for each spatial sample. This results in aliasing artifacts when synthesizing dynamic Depth-of-Field (DoF). Finally, the data size of each captured light field can easily reach 20 MB, prohibiting live streaming and processing at interactive frame rates. ☐ In this dissertation, I develop a new class of image processing algorithms and camera designs that can significantly improve the spatial, angular, and temporal resolution in light field imaging. ☐ Spatial Resolution: We develop a simple but effective technique by maneuvering the demosaicing process. We first show that traditional solutions that demosaic each individual microlense image and then blend them for DoF synthesis is suboptimal. We instead propose to demosaic the synthesized view at the rendering stage by first mapping the rays onto the refocusing plane and then conduct resampling. Our approach can significantly improve the spatial resolution while reducing the aliasing artifacts. ☐ Angular Resolution: We introduce a light field triangulation scheme to improve the angular resolution. Our triangulation technique aims to fill in the ray space with continuous and non-overlapping simplices anchored at sampled points (rays). Such a triangulation provides a piecewise-linear interpolant useful for angular super-resolution. We develop a novel triangulation algorithm that uses the depths and structures of 3D lines as constraints for producing high quality triangulations. For robust depth estimation, we further present two light field stereo matching algorithms that greatly outperform the state-of-the-art. ☐ Spatial-Angular Resolution: We further present a unified framework to simultaneously enhance the spatial and angular resolutions by stitching multiple light fields. We first estimate the warping function between two light fields and then stitch them by finding an optimal cut through the overlapping region. We further accelerate the graph-cut algorithm via a coarse-to-fine scheme. We demonstrate various stitching applications to improve the field-of-view as well as translational and rotational parallaxes of the light fields. ☐ Temporal Resolution: Finally, we construct a hybrid-resolution stereo camera system for acquiring and rendering dynamic light fields. Our system couples a high-res/low-res camera pair to replace the bulky camera array system. From the input stereo pair, we recover a low-resolution disparity map and upsample it via fast cross bilateral filters. We subsequently use the recovered high-resolution disparity map and its corresponding video frame to synthesize a light field using GPU-based disparity warping. Our system can produce racking and tracking focus effects at a resolution of 640x480 at 15 fps.
Integrating perspectives on social vulnerability to disasters and emergency management in Puerto Rico
(University of Delaware, 2013) Santos-Hernández, Jenniffer Marie
As economic losses associated to disasters continue on the rise, the study of disasters continues to show that the causes of these events are fundamentally social. In a macrocosm, this dissertation explores how the practice of emergency management may impact, address, or fail to address social vulnerability to disasters at the community level. This research explored how the emergency management organization evolved, how it functions, and how their services are delivered. In addition, it presents a case study of the 2009 explosion at a fuel storage facility in Cataño, Puerto Rico. This case study moves beyond inventories of indicators of social vulnerability to explore the interaction between the emergency management organization and community units during crisis and non-crisis times. Max Weber's ideal type of bureaucracy was used as a conceptual tool to guide the analysis and to explore management changes. The findings provide insights that could assist practitioners and researchers working in the areas of development, emergency management, bureaucratic change, decision-making, and policy making.
Development of RNA-based molecules for the inhibition of influenza A virus
(University of Delaware, 2014) Wang, Yue
Avian influenza has always been a serious threat to the poultry industry and public health. Limitations in the effectiveness and possible adverse effects of vaccines and antiviral drugs demonstrate the need to develop new prophylactic and therapeutic approaches. RNA silencing, an evolutionarily conserved pathway in many eukaryotic cells, has been utilized as a powerful tool to reduce gene expression levels as an approach for potential therapeutic uses. Previous studies have shown that small interfering RNAs (siRNAs), synthetic 19-21nt double-stranded RNAs, can significantly inhibit influenza virus replication both in vitro and in vivo by targeting viral mRNAs for degradation. The studies herein focus on developing RNAi molecules and constructs as potential alternative methods to control avian influenza. With the restrictions of sequence complementarity for efficient siRNA targeting and yet the existence of high sequence variation within a dynamically changing influenza population, viral RNAi targets has to be selected within highly conserved regions of the influenza virus genome. However, not all the conserved regions were found to be optimal for siRNA design. To address these challenges, I first developed a system for the accurate and rapid quantitation of influenza infectious titer and for monitoring the antiviral activity of siRNAs. Influenza vRNA/cRNA promoter-controlled GFP/luciferase expression plasmids were developed and compared for their sensitivity and accuracy in determining influenza virus infectious titers. The vRNA-promoter driven luciferase expression reporter was selected for its high sensitivity and lower background. Secondly, siRNAs targeting highly conserved regions across different influenza A virus strains were designed and optimized with sequence, structural or size modifications. Several modifications were found to improve the selected siRNAs' antisense-strand targeting efficiency and antiviral activity. Furthermore, to extend the practical application of anti-influenza RNAi, an influenza infection-inducible microRNA expression cassette was developed and demonstrated to have strong inhibitory activity on influenza virus replication.
From the endless summer to the surf spring: technology and governance in developing world surf tourism
(University of Delaware, 2014) Mach, Leon
This work explores the potential for resource users to self-organize to reduce or eliminate the negative impacts historically associated with surf tourism in developing countries - or in other words, the potential for user inspired governance, rather than governments to foster sustainable outcomes in areas where surf tourism is the dominant (if not only) source of tourism. This study proposes a new framework to contextualize developing world surf tourism (DWST), which combines knowledge from socio-ecological systems (SESs) studies and the growing body of work dedicated to characterizing co-evolving technology, environment, and society (TES) interrelationships. This framework is applied to a case study of volunteer surf tourism (VST) in Lobitos, Peru. Data was collected utilizing participant observation and informal interview methodologies during two field visits, which occurred in 2010 and 2014. This data was analyzed using the Framework Assessment for Sustainable Surf Tourism (FASST) to assess the role VST plays in shaping the overall surf tourism governance structure in Lobitos and to examine the sustainability of the surf tourism development that results. The findings reinforce the need for more careful consideration of how technology influences surf tourism governance at different scales.
Numerical schemes for coarse-graining of stochastic lattice dynamics
(University of Delaware, 2014) Song, Yan
This dissertation is focused on numerical schemes of coarse-graining (CG) for stochastic many-body microscopic models with short- and long-range interactions on 1-dimensional lattice systems. In this thesis, we focus on the numerical schemes of the coarse-graining (CG) Monte Carlo (CGMC) algorithms for 1) equilibrium states of 1-dimensional Ising-type models and 2) evolution of the dynamics on the path-wise level. Microscopic computational models for stochastic many particle systems such as Monte Carlo (MC) algorithms are typically formulated in terms of simple rules describing interactions between individual particles or spin variables. Due to the large size of particles and interactions between them, it represents a costly computational task for the direct numerical simulations. In contrast, the CGMC algorithms decrease the CPU times and substantial accelerate the resolution of the dynamics. In this thesis, I investigate the role of multi-body interactions in the construction of CG dynamics and demonstrate the efficiency and reliability of the two-body and three-body coarse-grained schemes. Furthermore, I explore the micro-macro parareal algorithm to study the evolution of dynamics of the stochastic lattice models described by continuous time Markov chains. Finally, I apply the information-theoretic tools for the parametrized coarse-graining method and estimate the evolution of the dynamics on the path-wise level. The results ae tested on model examples of lattice spin flip dynamics of one-dimensional Ising-type models.
Sculpting the citizen soldier: reproduction and national memory, 1865-1917
(University of Delaware, 2014) Beetham, Sarah Denver
This dissertation examines the development of the citizen soldier monument: the profusion of figures, obelisks, and columns that appeared after the Civil War in honor of the war veteran. I explore the citizen soldier monument in an effort to understand the relations between sculptural form, the formation of national memory, and the marketing of multiplied art in the late nineteenth century. Engaging with the work of scholars of Civil War memory outside the field of art history, including David Blight, John R. Neff, Drew Gilpin Faust, and Eric T. Dean, I offer a new interpretation of the importance of the citizen soldier monument in the American landscape. I propose that the citizen soldier monument is a phenomenon catering to the memorial needs of a culture struggling with meaning in the wake of America's first modern war. In this context, the soldier monument, so often interpreted as lacking originality, became an emblem for the enormity of Civil War death, the connection between local loss and national memory, and the tastes of a public trained to experience sculpture through plaster casts and other copies. In considering why these statues look the way they do, and how they came to be so popular, I propose that sculptural form is key to understanding the creation of national memory in the wake of the Civil War. In Chapter Two, I investigate the relationship between the monumental soldier, the reality of postwar life for the veteran, and the commemoration of the dead in the context of the nascent monument industry in the former Union states. Chapter Three considers how Southern Confederate monuments, using the same classical iconographies of victory employed in the North, negotiated the delicate ground of memorializing a lost cause during Reconstruction. In Chapter Four, I read Daniel Chester French's Minuteman as an emblem of Civil War commemoration, placing the Minuteman alongside the heightened rhetoric of Civil War reconciliation encouraged by the 1876 Centennial Exhibition in Philadelphia. And finally, Chapter Five examines the Spanish-American War, where copies of Hikers created by Theo Alice Ruggles Kitson and Allen George Newman were marketed by prestigious foundries, mirroring the global imperial concerns of the war in the standardization of production.
Design and packaging of ultra broadband lithium niobate modulator for millimeter-wave applications
(University of Delaware, 2014) Macario, Julien
Millimeter-waves have grown in popularity for imaging applications in recent years due to their unique properties. In the electromagnetic spectrum, millimeter-waves can be seen as the frontier between radio waves and optics and thus benefit to some extent from both worlds. On one hand, they are long enough to penetrate through obscurant and thin dielectric and experience low atmospheric attenuation. On the other hand, they are small enough to be relatively convenient for imaging by providing good resolution for a manageable aperture size. In addition, millimeter-wave imaging has also benefited directly from the recent emergence of new components in the millimeter-wave region, an effort mainly driven by the booming of the telecommunication market and the quest for bigger and faster networks. At the University of Delaware, we have spent the last decade developing passive millimeter-wave imaging systems at 35 GHz and in W band at 77 GHz and 94 GHz. The architecture of these systems is based on the optical upconversion of the native blackbody radiations emitted by the scene and detected by an antenna or a distributed aperture antenna array. The modulator converting the detected millimeter-wave radiations into the optical domain on a carrier is considered the heart of the detection technique. However, they are no commercially available modulators capable of operating in W band, which led us to develop our own. In this regard, I present an ultra broadband LiNbO3 electro-optic phase modulator based on ridge coplanar waveguide capable of operating in W band and well beyond. In addition to the modulator's design and fabrication process, I introduce a novel LiNbO3 micromachining process that eliminates substrate mode coupling in the millimeter-wave region. As results, optical modulation sidebands were observed over the full millimeter-wave spectrum. Modulation in the millimeter-wave region is interesting not only for imaging applications but also for the telecommunication industry. In that regard, I integrated the ultra broadband LiNbO3 modulator with a 1 mm coaxial connector in a fully packaged, low RF insertion loss, module for modulation operation over the 0-110 GHz band.
Probing for the effect of thyroid hormone receptors in different cancer phenotypes
(University of Delaware, 2014) Uceda, Gabriela
Thyroid hormone receptors (TRs) are ligand-dependent transcription factors that mediate many of the actions of the thyroid hormone in growth, development, and differentiation. Over the past decades significant advances have been made in the understanding of TR actions in maintaining normal cellular functions. However, the role/s of TRs in human cancer remain unclear to this day. TR alterations in the form of somatic mutations have been associated with several types of cancer, implying that TRs function as tumor suppressors. These TR mutants are usually impaired in T3-driven gene transcription and in many cases can function as dominant-negative inhibitors of wild-type TR activity. The Koh lab has generated tools to complement mutations with impaired transactivation. The hormone analog QH2 behaves as a "functionally orthogonal" ligand that rescues the transcriptional activity of the synthetic mutant TRbeta(H435A) that otherwise is not responsive to T3. QH2 can activate the TRbeta(H435A) mutant without stimulating wild-type TRs, including TRalpha;, which has been associated with cardiotoxic side effects. TRbeta; mutations at His435 have been found in genetic diseases such as resistance to thyroid hormone (RTH) and pituitary cancer (TSHoma), making QH2 and ideal candidate to potentially restore some of the cancer-associated phenotypes in in vitro assays. This orthogonal ligand-receptor pair may provide means to assess the role of mutant TRs in cancer progression. A second novel hormone analog developed in the Koh laboratory, JZ07, is a potent antagonist of wild-type TRs. If wild-type TRs function as tumor inducing factors due to their dual role in cancer development and progression, we envisioned JZ07 could attenuate this effect and inhibit metastasis-associated phenotypes. Many in vitro studies use supraphysiological concentrations of T3 to induce changes in cancer- associated phenotypes and to infer the role of TR. JZ07 will allow us to assess the role of a TR antagonist on TR function under normal or "euthyroid" conditions. This dissertation evaluates the use of these TR modulators as tools to assess the contribution of TRs in cancer-associated phenotypes. Expression of TRs proved to inhibit the invasive and migratory activities of cells, suggesting TRs could function as tumor suppressors. Evaluation of the hormone analogs QH2 and JZ07 induced additional effects in the different metastatic phenotypes. QH2 did not affect the increased invasive and proliferative activities of the mutant TRbeta(H435A), however TRbeta(H435A) did not repress invasion as would be expected if TRbeta(H435A) behaved similar to unliganded TRbeta(wt). The orthogonal ligand enhanced migration in the mutant TRbeta(H435A) but clear non-genomic effects are also observed in wild-type expressing cell lines. The novel hormone analog JZ07 successfully recapitulated its antagonistic behavior in the invasive activity of wild-type TRs in an isotype-dependent manner and further inhibited invasion in TRbeta(wt) cells. Nevertheless, the inhibitory effect in the migration activity of the mutant TRbeta(H435A) and Neo control cells cannot be explained by classical transactivation action alone. Together, this suggests that the role of TRs in cancer-associated phenotypes of migration, invasion and proliferation likely involve non-genomic actions of TRs and the affects of T3 on these cell phenotypes likely involves T3 acting on cellular targets other than TRs.
Emanuel de witte's sermon paintings: sight, sound and spirituality
(University of Delaware, 2014) Bordeaux, Sara Rachel
This dissertation proposes a revised view of Emanuel de Witte's Calvinist church interior paintings as sites of spirituality that evoke the sensory experience of attending church. Calvin's objection to devotional art precipitated the traditional understanding of these paintings as perspectives, which privileges their architectural elements and diminishes their spirituality. Because paintings by De Witte and his contemporaries represent structures recently stripped of most Catholic accoutrements, art historians have described them as spare spaces fit for a faith based solely on scripture. However, De Witte's sermon paintings assert Calvinist presence by showing the Reformed faithful at worship. De Witte utilizes paint to evoke the experiences of looking and listening, which encourages the viewer-as-congregant to attend the painted service. I suggest that we may identify a distinctly Reformed image in the subject matter, style, and technique of De Witte's paintings, which introduce a new visual and aural vocabulary to represent an aniconic faith. This dissertation fills a lacuna in the scholarship on Emanuel de Witte, whose oeuvre has not been the sole subject of study since Ilse Manke's 1963 monograph. Whereas De Witte's brief career in Delft has received attention in abundant literature on the Delft School, my focus on his Amsterdam paintings enhances our understanding of Calvinist identity and worship in Amsterdam's multiconfessional environment. My exploration of the sensory appeal of De Witte's paintings recasts Calvinism in Early Modern Europe as a profoundly experiential faith. In light of the Calvinist Church's mutability during the seventeenth century, it is possible that De Witte's paintings contribute to the formation of Dutch Calvinist identity by picturing the Reformed congregation practicing their faith. De Witte's paintings may be understood as a fundamentally new kind of religious art that depicts sacred spaces activated by the communities within them. His painted sermons represent the Word made image.
Building energy governance in Shanghai
(University of Delaware, 2014) Kung, YiHsiu Michelle
With Asia's surging economies and urbanization, the region is adding to its built environment at an unprecedented rate, especially those population centers in China and India. With numerous existing buildings, plus a new building boom, construction in these major Asian cities has caused momentous sustainability challenges. This dissertation focuses on China's leading city, Shanghai, to explore and assess its existing commercial building energy policies and practices. Research estimates that Shanghai's commercial buildings might become a key challenge with regard to energy use and CO2 emissions as compared to other major Asian cities. Relevant building energy policy instruments at national and local levels for commercial buildings are reviewed. In addition, two benchmarks are established to further assess building energy policies in Shanghai. The first benchmark is based on the synthesis of relevant criteria and policy instruments as recommended by professional organizations, while the second practical benchmark is drawn from an analysis of three global cities: New York, London and Tokyo. Moreover, two large-scale commercial building sites - Shanghai IKEA and Plaza 66 - are selected for investigation and assessment of their efforts on building energy saving measures. Detailed building energy savings, CO2 reductions, and management cost reductions based on data availability and calculations are presented with the co-benefits approach. The research additionally analyzes different interventions and factors that facilitate or constrain the implementation process of building energy saving measures in each case. Furthermore, a multi-scale analytical framework is employed to investigate relevant stakeholders that shape Shanghai's commercial building energy governance. Research findings and policy recommendations are offered at the close of this dissertation. Findings and policy recommendations are intended to facilitate commercial building energy governance in Shanghai and other rapidly growing second-tier or third-tier cities in China, and to further contribute to the general body of knowledge on Asia's urban building sustainability.
Nanostructured nitrogen and carbon codoped TiO2 thin films: synthesis, structural characterization and optoelectronic properties
(University of Delaware, 2014) Ruzybayev, Inci
TiO2 is widely used in applications like photocatalysis, sensors, solar cells, and memory devices because it is inexpensive, abundant, nontoxic and stable in aqueous solution. Another exciting application where TiO 2 has the potential to be a very useful catalyst is the clean hydrogen generation using solar radiation. Energy consumption is increasing every year and, as a result, renewable and sustainable alternative energy sources are becoming increasingly important. Therefore, clean hydrogen generation research is becoming more and more important. This study aims at the preparation and characterization of nitrogen and carbon (N-C) codoped TiO 2 photoanode material that could potentially be used in photoelectrochemical cells for hydrogen generation. The solar spectrum peaks around 500 nm (2.48 eV) which is in the visible part of the spectrum. The photoanode material to be used for solar hydrogen generation should absorb visible light photons to yield high efficiency. The challenge with TiO2 is that the wide band gap (3.00-3.20 eV) absorbs only ultra-violet (UV) photons and only a small percentage of the solar spectrum is in the UV range. There are various ways to overcome the challenge of sensitizing the material to visible light absorption and this study focuses on one of the most promising ways: band modification of TiO 2 by N-C codoping. The role of pure oxygen pressure on pulsed laser deposited N-C codoped TiO2 films were investigated. At low pressures rutile phase of TiO2 was dominant and a microstructure with densely packed grains was obtained. However, at high pressures anatase phase became dominant and columnar structure was favored. Therefore, the anatase-rutile phase ratio as well as the microstructure of the films can be controlled by adjusting oxygen pressure and introducing N and C into the TiO 2 matrix. Optimized oxygen pressure and higher doping concentrations yielded films with more effective absorption in the visible region. The preparation and characterization of pulsed laser deposited N-C codoped TiO2 thin films were investigated for dopant incorporation using N2 and CH4 gases. Polycrystalline anatase structured films were obtained. A 2 theta shift of the anatase (101) X-ray diffraction main peak towards lower values indicated carbon incorporation into the lattice. N incorporation was confirmed with observed Ti-N bonds using X-ray photoelectron spectroscopy. Optical data showed significant reduction, approximately 1.00 eV, of the band gap. The reduction of the band gap allowed the photons in the visible part of the solar spectrum to be absorbed. Through a collaborative work with scientists at Brookhaven National Laboratory and Yonsei University, precise modeling of the electronic structure of N-C codoped TiO2 films were carried out to reveal the underlying physics of band gap reduction. Experimental results were compared with first-principle density functional theory calculations. Hard X-ray photoelectron spectroscopy showed that O, N and C 2p states overlapped effectively and shifts in the valence band maximum towards the Fermi level were observed. Optical band gap results showed that N-C codoping is an effective route for band gap reduction in TiO 2 . Comparison of the measured valence band structure with theoretical photoemission density of states further revealed C substitution on the Ti site and N substitution on the O site. Finally, films grown using radio frequency (rf) magnetron sputtering were compared with the pulsed laser deposited films. Sputtered N-C codoped TiO2 films showed phase transformation from anatase to rutile at constant argon pressure with increasing doping concentration. Moreover, with slow-rate N-C codoping of TiO2 , a texturing effect was observed in X-ray diffraction scans such that anatase (004) Bragg reflection plane became more favored over anatase (101). Optical band gap was reduced but the reduction was not as significant as in the films prepared with the pulsed laser deposition method. Electrochemical methods were applied in the photoelectrochemical cell and the sample prepared by using TiO 2 target with 8% N and C atomic concentrations found to have slightly better photoactivity relative to the other N-C codoped samples. However, due to preferential anatase (004) plane, overall efficiency of N-C codoped films was low. In conclusion, pulsed laser deposition is preferred over rf magnetron deposition for the purpose of band gap reduction of TiO2 by N and C codoping. Pulsed laser deposited films showed continuum in C and N 2 p dopant states within the forbidden region and these states overlapped well with O 2p states. For this reason, optical band gap measurements showed significant reduction. Therefore, pulsed laser deposition of N-C codoped TiO2 films is a possible way of photoanode fabrication for solar hydrogen generation. (Abstract shortened by UMI.)
Hybrid light emitting diodes based on solution processed polymers, colloidal quantum dots, and colloidal metal nanoparticles
(University of Delaware, 2014) Ma, Xin
This dissertation focuses on solution-processed light-emitting devices based on polymer, polymer/PbS quantum dot, and polymer/silver nanoparticle hybrid materials. Solution based materials and organic/inorganic hybrid light emitting diodes attracted significant interest recently due to many of their advantages over conventional light emitting diodes (LEDs) including low fabrication cost, flexible, high substrate compatibility, as well as tunable emission wavelength of the quantum dot materials. However, the application of these novel solution processed materials based devices is still limited due to their low performances. Material properties and fabrication parameters need to be carefully examined and understood for further device improvement. This thesis first investigates the impact of solvent property and evaporation rate on the polymer molecular chain morphology and packaging in device structures. Solvent is a key component to make the active material solution for spin coating fabrication process. Their impacts are observed and examined on both polymer blend system and mono-polymer device. Secondly, PbS colloidal quantum dot are introduced to form hybrid device with polymer and to migrate the device emission into near-IR range. As we show, the dithiol molecules used to cross-link quantum dots determine the optical and electrical property of the resulting thin films. By choosing a proper ligand for quantum dot ligand exchange, a high performance polymer/quantum dot hybrid LED is fabricated. In the end, the interaction of polymer exciton with surface plasmon mode in colloidal silver nanoparticles and the use of this effect to enhance solution processed LEDs' performances are investigated.
Exploring the relationship between trees and stress in the urban environment
(University of Delaware, 2014) Townsend, Joseph B.
The research literature describes a positive relationship between seeing plants and human well-being. More rapid recovery from surgery, reduced incidence of neighborhood crime, increased baby birth weight and increased trust of neighborhood merchants are among the benefits attributed to exposure to trees and shrubs. This thesis attempts to find a common explanation for these outcomes. It examines the connection between urban trees and community stress. Each of the above outcomes can be attributed, in part, to stress reduction. The literature indicates that stress reduction is one of the consequences of exposure to plants. Stress levels were measured at the block level in Wilmington Delaware by means of a survey mailed to 1982 residents. Physical conditions were catalogued using an on-site inventory. The survey and inventory demonstrated that the total number of trees on a block has a strong negative relationship with community stress and a positive relationship with self-reported health. The results suggest that moderation of stress is one of the factors that underlies the beneficial consequences of exposure to green vegetation on inner city blocks. This research should prove useful to city planners and urban residents alike.
Objects and anxiety in late medieval English writing
(University of Delaware, 2014) Parkin, Gabrielle
In this study I demonstrate that medieval goods were active and often animated participants in the daily lives of medieval individuals. My project demonstrates how, rather than merely giving voice to dead objects, these lively "things" speak about the emotional, sensual, and experiential lives of late medieval men and women. By bringing together a group of seemingly disparate goods--Books of Hours, stone idols and invisible flowers, clothing, and skull cups--I argue that each object provides a spectrum of possible readings for users, who simultaneously interpreted objects as essential to a spiritual and communal existence, while also fearing that goods might inhibit the soul's relationship with the divine. All matter was, in some way, linked with creation and the divine, and as a result objects inherently possessed degrees of agency that might affect the human user. ☐ Chapter One considers how Books of Hours combine animal, plant, and stone matter and join them with prayers and illuminated images to instruct women in proper touching in this life and the next. In Chapter Two I consider worldly and mystical matter in Chaucer's "Second Nun's Tale" to demonstrate how looking at and touching manmade objects can ultimately limit knowledge of the divine. Though Chaucer provides an exemplum in the form of St. Cecile, who requires no contact with goods to realize her destiny of becoming an early Christian martyr, he ultimately concludes that, for less saintly individuals, it is impossible to ignore the senses, and particularly vision, when forming belief. Chapters Three and Four discuss Margery Kempe's worldly and religious attire. I argue that Margery's clothes and tears become a form of livery that reinforces her relationship with the Heavenly household. As a result, her text itself is actually a narrative of cloth, in which she employs a sartorial vocabulary to understand her transition from mother to mystic. In Chapter Five, I focus on the tale of "Albinus and Rosemund" in John Gower's Confessio Amantis and consider how the substance or matter of an object has inherent power, even if it cannot be perceived immediately though senses. In that tale, the central object, a golden and bejeweled cup that was crafted from a human skull, controls the destiny of all the characters.
Scalar implicatures in children: alternatives and relevance
(University of Delaware, 2014) Skordos, Dimitrios
Utterances like "Megan ate some of the cupcakes" are typically interpreted as "Megan ate some but not all of the cupcakes". Such an interpretation is thought to arise from a pragmatic inference called Scalar Implicature (SI). Preschoolers typically fail to spontaneously generate SIs without the assistance of training or context that makes the stronger alternative salient. However, the exact role of alternatives in generating SIs remains contested. Furthermore, it is not clear whether children take into account the goal of the conversation in considering scalar alternatives and generating SIs. We present three studies with English-speaking preschoolers and adults designed to address these questions. We show that the presence of stronger alternative is important for SI generation (Experiment 1), that the stronger alternative leads to SI generation only when it is relevant to the goal of conversation (Experiment 2) and that relevance does not simply mediate, but in fact drives accessibility of the alternatives (Experiment 3). We discuss the implications of these findings for pragmatic inference and the study of pragmatic development in general.

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