Digital Commons Network^™

In Vivo Non-Invasive Monitoring Of Optically Resonant Metal Nanoparticles Using Multi-Wavelength Photoplethysmography, Gregory J. Michalak

Doctoral Dissertations

Nanotechnology has recently emerged as a powerful modality in many biomedical applications. In particular, several classes of nanoparticles have been employed as cancer therapy and imaging contrast agents. These particles can have architecture of varying complexity, depending on their specific application. These complex architectures are achieved by various chemical techniques usually performed in specific sequences to add complexity and functionality. One such class of nanoparticle, used in tumor treatment and as contrast agents in several optical imaging techniques, is the plasmon resonant metal nanoparticle. The most common metal used for these particles is gold because of its biocompatibility, lack of …

Elimination Of Deck Joints Using A Corrosion Resistant Frp Approach, Ashok Reddy Aleti

Doctoral Dissertations

The research presented herein describes the development of durable link slabs for jointless bridge decks based on using FRP grid for reinforcement. Specifically, the ductility of the FRP material was utilized to accommodate bridge deck deformations imposed by girder deflection, temperature variations, and concrete shrinkage. It would also provide a solution to a number of deterioration problems associated with bridge deck joints.

The design concept of the link slabs was then examined to form the basis of design for FRP grid link slabs. Improved design of FRP grid link slab/concrete deck slab interface was confirmed in the numerical analysis. The …

Mitigation Of Chloride And Sulfate Based Corrosion In Reinforced Concrete Via Electrokinetic Nanoparticle Treatment, Kunal Kupwade-Patil

Doctoral Dissertations

Concrete is a porous material which is susceptible to the migration of highly deleterious species such as chlorides and sulfates. Various external sources, including sea salt spray, direct seawater wetting, deicing salts and chlorides can contaminate reinforced concrete. Chlorides diffuse into the capillary pores of concrete and come into contact with the reinforcement. When chloride concentration at the reinforcement exceeds a threshold level it breaks down the passive oxide layer, leading to chloride induced corrosion. The application of electrokinetics using positively charged nanoparticles for corrosion protection in reinforced concrete structures is an emerging technology. This technique involves the principle of …

Communication-Avoiding Krylov Subspace Methods, Mark Frederick Hoemmen '98

Doctoral Dissertations

No abstract provided.

Sound Pressure Levels Measured At Preferred Listening Levels Of Ipod Users Using Knowles Electronic Manikin For Acoustical Research, Ahmad Brandelle Alexander

Doctoral Dissertations

The present study (1) examined the sound pressure levels (SPLs) of iPod users and nonusers at preferred listening levels measured on Knowles Electronic Manikin for Acoustical Research (KEMAR), and (2) determined if those SPLs exceeded the OSHA standards for acceptable hearing levels. Forty subjects, divided into one of the four following groups participated in this study: (1) inexperienced males, (2) experienced males, (3) inexperienced females, or (4) experienced females. Each participant was asked to set the music stimuli to their preferred listening level while in the presence of background noise, simulating a real world listening environment. SPL values were then …

Accurate And Stable Numerical Methods For Solving Micro Heat Transfer Models In An N-Carrier System In Spherical Coordinates, Di Zhao

Doctoral Dissertations

Energy exchange between electrons and phonons in metal provides the best example in describing non-equilibrium heating during the ultrafast transient. In times comparable to the thermalization and relaxation time of electrons and phonons, which are in the range of a few to several tens of picoseconds, heat continuously flows from hot electrons to cold phonons through mutual collisions. Consequently, electron temperature continuously decreases whereas phonon temperature continuously increases until thermal equilibrium is reached. Tien developed the well-known parabolic two-step model for describing the non-equilibrium heating in the electron-phonon system in 1992, and Tzou developed the parabolic model for the non-equilibrium …

Experimental Investigation Of Flow And Heat Transfer Characteristics Of R -134a In Microchannels, Abdullahel Bari

Doctoral Dissertations

The purpose of this study was to investigate the flow and heat transfer characteristics of liquid refrigerant R-134a in rectangular microchannels. The research concentrated mostly upon single-phase experiments with limited investigation of boiling phenomenon in microchannels. Tests were performed using rectangular microchannels with hydraulic diameters ranging from 112 μm to 210 μm and aspect ratios varying approximately from 1.0 to 1.5. The Reynolds number in the experiments ranged from 1,200 to 13,000 although most data were collected in the transition and turbulent flow regimes.

The experimental data for friction factor measurement had a similar trend as predicted by macroscale theory …

The Effects Of Asymmetric Directional Microphone Fittings On Acceptance Of Background Noise, Jong Sik Kim

Doctoral Dissertations

The present study investigated the effects of asymmetric directional microphone fittings (i.e., an omnidirectional microphone on one ear and a directional microphone on the other) on speech understanding in noise and acceptance of background noise in 15 full-time hearing aid users. Subjects were fitted binaurally with four directional microphone conditions (i.e., binaural omnidirectional, asymmetric right directional, asymmetric left directional and binaural directional microphones) using Siemens Intuis directional behind-the-ear hearing aids and comply earmolds. The results revealed that speech understanding in noise improved when using asymmetric directional microphones compared to binaural omnidirectional microphone fittings and were not significantly hindered compared to …

Dna Microarray Image Segmentation Using Active Contours Without Edges Method, Shenghua Ni

Doctoral Dissertations

The goal of this dissertation is to build a better segmentation method for DNA microarray image processing. Segmentation is a partitioning process used to separate a spot area from a non-spot area in DNA microarrays. It directly affects the accuracy of gene expression analysis in the data mining process that follows. A number of DNA microarray segmentation methods have been proposed in the area, but even modern segmentation methods seem to have accuracy problems. In this dissertation, I will present a segmentation method based on the Active Contours Without Edges (ACWE) algorithm and apply it to two types of DNA …

Analysis Of Conjugated Polymer Nanotubules Formed By Template Wetting Nanofabrication, Steven D. Bearden Jr.

Doctoral Dissertations

Semiconducting and optoelectric conjugated polymers have potential in micro and nano-electronic applications. Their widely tunable physical conformations and orientations make these polymers ideal material for engineering small scale devices. The polymers have been incorporated into several electronic devices including light-emitting diodes, solar cells, and field-effect transistors. Widespread adoption of these materials will not be a reality until the issues of poor device performance, short lifespans, and device degradation are resolved.

Nanostructures have been demonstrated to have improvements in molecular ordering and electronic transport. In the work presented here, tubular nanostructures of conjugated polymers fabricated by the template wetting nanofabrication process …

Development Of A Geopolymer-Based Cementitious Coating For The Rehabilitation Of Buried Concrete Infrastructure, Carlos Montes

Doctoral Dissertations

The current research project was devoted to the incorporation of geopolymers as a new material for Trenchless projects, taking advantage of their properties in a field in which they had not been used before, providing a substantial help to municipalities to meet their rehabilitation needs. Trenchless Technologies are a family of methods, materials and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities.

The dissertation research work described herein is divided into six primary objectives: (1) the evaluation of geopolymer as …

Associative Pattern Mining For Supervised Learning, Harpreet Singh

Doctoral Dissertations

The Internet era has revolutionized computational sciences and automated data collection techniques, made large amounts of previously inaccessible data available and, consequently, broadened the scope of exploratory computing research. As a result, data mining, which is still an emerging field of research, has gained importance because of its ability to analyze and discover previously unknown, hidden, and useful knowledge from these large amounts of data. One aspect of data mining, known as frequent pattern mining, has recently gained importance due to its ability to find associative relationships among the parts of data, thereby aiding a type of supervised learning known …

On Calculating Residuated Approximations And The Structure Of Finite Lattices Of Small Width, Wu Feng

Doctoral Dissertations

The concept of a residuated mapping relates to the concept of Galois connections; both arise in the theory of partially ordered sets. They have been applied in mathematical theories (e.g., category theory and formal concept analysis) and in theoretical computer science. The computation of residuated approximations between two lattices is influenced by lattice properties, e.g. distributivity.

In previous work, it has been proven that, for any mapping f : L → [special characters omitted] between two complete lattices L and [special characters omitted], there exists a largest residuated mapping ρf dominated by f, and the notion of "the shadow …

Protection-Motivated Behaviors Of Organizational Insiders, Michael C. Posey

Doctoral Dissertations

Protecting information from a wide variety of security threats is an important and sometimes daunting organizational activity. Instead of solely relying on technological advancements to help solve human problems, managers within firms must recognize and understand the roles that organizational insiders have in the protection of information. The systematic study of human influences on organizational information security is termed behavioral information security (Fagnot 2008; Stanton, Stam, Mastrangelo, and Jolton 2006), and it affirms that the protection of organizational information assets is best achieved when the detrimental behaviors of organizational insiders are effectively deterred and the beneficial activities of these individuals …

Identifying Multiple Steady States In The Design Of Reactive Distillation Processes, Thomas Karl Mills

Doctoral Dissertations

"Global homotopy continuation is used to identify multiple steady states in ideal reactive flash and reactive distillation systems involving a reaction of the form A+B [symbol for <--> C taking place in the liquid phase. The choice of specifications has an influence on the existence of multiple solutions for both the flash and the column. For the flash, specification of the heat input or withdrawal can give rise to multiplicities while specification of the split fraction does not. Specification of one internal energy balance variable and one external material balance variable does not produce multiplicities in the column; however, specification of …

At The Crossroads Of Learning And Culture : Identifying A Construct For Effective Computer-Assisted Language Learning For English Language Learners, Yun Shaw

Doctoral Dissertations

NA

A Rotating Ring-Disk Study Of Interactions Among Sps, Cuprous Ions, And Oxygen, Yi-Hsin Chen

Doctoral Dissertations

The most common additives in copper plating baths for deep via filling are chloride, polyethylene glycol (PEG), a suppressor, and bis-(3-sulfopropyl)-disulfide (SPS), an accelerant. The copper in acid plating baths is provided by a Cu (II) salt. Cu (I) may be present as well and it influenced the effectiveness of SPS. In this investigation, the interactions among SPS, Cu (I) and oxygen were studied by rotating ring-disk voltammetry. The ring electrode acted as a plating substrate, while Cu (I) was generated at the disk by anodic dissolution of copper. Because Cu (I) is consumed by reaction with oxygen, the experiments …

Experimental Evolution Of Burkholderia Cenocepacia Biofilm Populations, Steffen R. Poltak

Doctoral Dissertations

Many biofilm populations are known for their exceptional biodiversity but the relative contributions of the forces that could promote this diversity are poorly understood. This uncertainty pervades in the well-established communities found on many natural surfaces and in long-term, chronic infections. Here we describe the parallel evolution of cooperative communities derived from a clone of Burkholderia cenocepacia during approximately 1500 generations of biofilm selection. This long-term evolution was enabled by a new experimental method that selects for daily cycles of colonization, biofilm assembly, and dispersal. Each of six replicate biofilm populations underwent a common pattern of adaptive morphological diversification, in …

A High Speed Serializer/Deserializer Design, Yifei Luo

Doctoral Dissertations

A Serializer/Deserializer (SerDes) is a circuit that converts parallel data into a serial stream and vice versa. It helps solve clock/data skew problems, simplifies data transmission, lowers the power consumption and reduces the chip cost. The goal of this project was to solve the challenges in high speed SerDes design, which included the low jitter design, wide bandwidth design and low power design.

A quarter-rate multiplexer/demultiplexer (MUX/DEMUX) was implemented. This quarter-rate structure decreases the required clock frequency from one half to one quarter of the data rate. It is shown that this significantly relaxes the design of the VCO at …

Creek Diplomacy In An Imperial Atlantic World, Deena L. Parmelee

Doctoral Dissertations

"Creek Diplomacy in an Imperial Atlantic World," argues that Creek leaders saw opportunities for Creek peoples to play an important political and economic role in the Atlantic world even while the Confederacy itself was still forming. This study explores Creek participation in the Atlantic world in two ways. First, it traces Creek diplomatic travel to European centers. Second, it examines Creek reception of European traders and diplomats in Creek towns. In this way, it traces Creek diplomacy in its external and internal forms, as Creeks moved outward to establish diplomatic relations with others, and dealt with outsiders who came to …

Hyperpolarized Xenon-129 Magnetic Resonance Imaging Of Functional Lung Microstructure, Isabel Dregely

Doctoral Dissertations

Hyperpolarized 129Xe (HXe) is a non-invasive contrast agent for lung magnetic resonance imaging (MRI), which upon inhalation follows the functional pathway of oxygen in the lung by dissolving into lung tissue structures and entering the blood stream. HXe MRI therefore provides unique opportunities for functional lung imaging of gas exchange which occurs from alveolar air spaces across the air-blood boundary into parenchymal tissue. However challenges in acquisition speed and signal-to-noise ratio have limited the development of a HXe imaging biomarker to diagnose lung disease.

This thesis addresses these challenges by introducing parallel imaging to HXe MRI. Parallel imaging requires dedicated …

The Application Of Computational Modeling To Data Visualization, Daniel S. Pineo

Doctoral Dissertations

Researchers have argued that perceptual issues are important in determining what makes an effective visualization, but generally only provide descriptive guidelines for transforming perceptual theory into practical designs. In order to bridge the gap between theory and practice in a more rigorous way, a computational model of the primary visual cortex is used to explore the perception of data visualizations.

A method is presented for automatically evaluating and optimizing data visualizations for an analytical task using a computational model of human vision. The method relies on a neural network simulation of early perceptual processing in the retina and visual cortex. …

Volatile Organic Compounds In The New England Troposphere: Atmospheric Chemistry And Measurement Techniques, Jesse L. Ambrose

Doctoral Dissertations

Atmospheric measurements made at Appledore Island, Maine were used to investigate nighttime nitrate radical (NO3) chemistry and its significance for the nitrogen oxides (NOx = NO + NO2) budget in the Gulf of Maine region during the summer of 2004 International Consortium for Atmospheric Research on Transport and Transformation field campaign. Removal of NOx was strongly dependent on reactions of NO3 with biogenic volatile organic compounds and the fate of dinitrogen pentoxide (N 2O5). For three case studies, temporal profiles of NO 3 were calculated from measured parameters. Comparisons between measured and calculated NO3 mixing ratios highlighted significant uncertainties in …

Microstructural Evolution Of Sputtered Phase Segregated Metal Composite Thin Films, Dana I. Filoti

Doctoral Dissertations

In this thesis, we present the first comparative study of crystallographic texture development in three different types of metal thin film composites: fully miscible (Au-Ag), slightly immiscible (Cu-Ag) and immiscible (Au-SiO 2). Texture development refers to the distribution of orientations of crystallites in polycrystalline thin films, and is an important part of the microstructure that determines thin film properties. A material's crystallographic texture needs to be understood because of its sensitivity to the energetic growth conditions. By controlling the microstructure, a material can be tailored to specific applications. We investigated in comparison the texture and microstructure evolution in metal composite …

Space- And Ground-Based Observations Of Pulsating Aurora, Sarah Jones

Doctoral Dissertations

Pulsating aurora is a frequently occurring phenomenon generally believed to occur mainly in the aftermath of a substorm, resulting in widespread auroral luminosity corresponding to a significant transfer of power from the magnetosphere to the ionosphere. A handful of theories have been proposed to explain the associated precipitation mechanism, which have been shown to ineffectively explain certain aspects of pulsating aurora. Previous research into pulsating aurora has provided a wealth of observations, yet much remains unknown about this phenomenon and some previous observations are contradictory. The focus of this presentation is the analysis of ground- and space-based measurements of pulsating …

Topics In Access, Storage, And Sensor Networks, Swapnil Bhatia

Doctoral Dissertations

In the first part of this dissertation, Data Over Cable Service Interface Specification (DOCSIS) and IEEE 802.3ah Ethernet Passive Optical Network (ETON), two access networking standards, are studied. We study the impact of two parameters of the DOCSIS protocol and derive the probability of message collision in the 802.3ah device discovery scheme. We survey existing bandwidth allocation schemes for EPONs, derive the average grant size in one such scheme, and study the performance of the shortest-job-first heuristic.

In the second part of this dissertation, we study networks of mobile sensors. We make progress towards an architecture for disconnected collections of …

Ratiometric Fluorescent Metal Ion Indicators Based On Functionalized Poly(N -Isopropylacrylamide), Jie Du

Doctoral Dissertations

A novel type of ratiometric fluorescent indicator based on the phase transition of a well-known stimuli-responsive polymer poly(N-isopropylacrylamide) (PNIPAM) is presented. The sensing mechanism involves the polymer conformational change resulting from charge neutralization by the analyte metal ions. The ultimate goal is to develop ratiometric fluorescent indicators for free Cu(II) in environmental water analysis.

The indicators are copolymers of N-isopropylacrylamide (NIPAM) with small percentages of fluorophores and ligand monomers. The charges on the ligands prevent PNIPAM from collapsing unless neutralized upon metal ion chelation. The polymer phase transition is transduced by either fluorescence solvatochromism or fluorescence resonance energy transfer (FRET), …

Community Change In The Northern Forest, Chris R. Colocousis

Doctoral Dissertations

In 2006, the pulp mill in Berlin, NH was closed and dismantled, marking an end to more than a century of dependence on the pulp and paper industry. The city's location in a high-amenity and recreation-dependent region suggests that the rebirth of the local economy would follow a general transition from a production orientation to consumption. Using in-depth interviews and other qualitative methods, survey work, and secondary quantitative data I chronicle a century change, focusing on how the industry has shaped the community and its present ability to reinvent itself. I analyze the ways in which patterns of change and …

From Biosphere To Noosphere: Vladimir Vernadsky's Theoretical System As A Conceptual Framework For Universal Sustainability Education, Irina L. Trubetskova

Doctoral Dissertations

In light of accelerating global warming and climate change, the importance of sustainability education is unquestionable. It is a requirement of our time that sustainability education must become a part of any professional curriculum in higher education because today's college students are tomorrow's decision makers and the key players at local, national, and international levels.

Although the importance of education for a sustainable future has been recognized by the global community and we are now living through the United Nations Decade of Education for Sustainable Development (2005-2014), a common conceptual approach to teaching sustainability does not exist. We face a …

Development Of Ground-Based Search -Coil Magnetometer Systems In The Polar Regions And Studies Of Ulf Pc 1--2 Wave Propagation In The Ionospheric Waveguide, Hyomin Kim

Doctoral Dissertations

Search-coil magnetometers, which measure time-varying magnetic flux density (dB/dt) and its direction, have been developed for the observations of geomagnetic pulsations in the ultra low frequency (ULF) range (a few mHz to a few Hz). The design, fabrication, and test/calibration have been performed to detect very weak geomagnetic pulsations with approximately a few pT resolution over the frequency range 0 --- 2.5 Hz and 100 musec timing accuracy, given a system gain of 4.43 V/(nT·Hz) and 12-bit analog-to-digital converter (ADC) with GPS time stamps. These instruments are deployed in the Polar regions forming high latitude networks and conjugate measurement points …