Physical Sciences and Mathematics Commons^™

Modeling Colony Collapse Disorder In Honeybees As A Contagion, Christopher David Kribs, Christopher Mitchell

Mathematics Faculty Publications

Honeybee pollination accounts annually for over $14 billion in United States agriculture alone. Within the past decade there has been a mysterious mass die-off of honeybees, an estimated 10 million beehives and sometimes as much as 90% of an apiary. There is still no consensus on what causes this phenomenon, called Colony Collapse Disorder, or CCD. Several mathematical models have studied CCD by only focusing on infection dynamics. We created a model to account for both healthy hive dynamics and hive extinction due to CCD, modeling CCD via a transmissible infection brought to the hive by foragers. The system of …

Changing Lead Into Gold: Examining Agency Attempts To Use The Clean Water Act To Solve Ecosystem Degradation Issues, N. Lindsay Simmons

William & Mary Environmental Law and Policy Review

No abstract provided.

Navigating Through The Confusion Left In The Wake Of Rapanos: Why A Rule Clarifying And Broadening Jurisdiction Under The Clean Water Act Is Necessary, Kristen Clark

William & Mary Environmental Law and Policy Review

No abstract provided.

Shoreline Evolution: Fairfax County, Virginia Potomac River Shoreline, Donna A. Milligan, Christine A. Wilcox, C. Scott Hardaway Jr.

Reports

Fairfax County is situated along the upper reaches of the Potomac River (Figure 1). Because the County’s shoreline is continually changing, determining where the shoreline was in the past, how far and how fast it is moving, and what factors drive shoreline change will help define where the shoreline will be going in the future. These rates and patterns of shore change along Chesapeake Bay’s estuarine shores will differ through time as winds, waves, tides and currents shape and modify coastlines by eroding, transporting and depositing sediments.

The purpose of this report is to document how the shore zone of …

Mathematical Modeling Of Immune Responses To Hepatitis C Virus Infection, Ivan Ramirez

Electronic Theses and Dissertations

An existing mathematical model of ordinary differential equations was studied to better understand the interactions between hepatitis C virus (HCV) and the immune system cells in the human body. Three possible qualitative scenarios were explored: dominant CTL response, dominant antibody response, and coexistence. Additionally, a sensitivity analysis was carried out to rank model parameters for each of these scenarios. Therapy was addressed as an optimal control problem. Numerical solutions of optimal controls were computed using a forward-backward sweep scheme for each scenario. Model parameters were estimated using ordinary least squares fitting from longitudinal data (serum HCV RNA measurements) given in …

Neotectonic-Period Characteristics, Seismicity, Geometry And Segmentation Of The Tuz Gölü Fault Zone, Akın Kürçer, Yaşar Ergun Gökten

Bulletin of the Mineral Research and Exploration

The Tuz Gölü Fault Zone (TGFZ) is one of the most important active intra-continental fault zones in central Anatolia. The TGFZ with nearly 200 km in length and 2-25 km in width is a NW trending, active normal fault zone with minor right-lateral strike-slip component. It extends between the north of Lake Tuz at NW and at Kemerhisar (Ni¤de) SE. This zone is a transition zone that separates the Central Anatolian Neotectonic Region into two-sub neotectonic regions, namely Kayseri-Sivas and Konya-Eskiflehir neotectonic regions. In this study, Neotectonicperiod characteristics, seismicity, geometry and segmentation of TGFZ are investigated. TGFZ is composed of …

Protolith Nature And Tectonomagmatic Features Of Amphibolites From The Qushchi Area, West Azerbaijan, Nw Iran, Mohssen Moazzen

Bulletin of the Mineral Research and Exploration

Amphibolites from the Qushchi area in west Azerbaijan province, NW Iran are metabasites containing hornblende, plagioclase, epidote, garnet, relict igneous clinopyroxene and titanite, apatite and opaque minerals as accessory phases. They are spatially associated with an ophiolitic mélange but their relationship is not clear. Based on whole rock geochemistry of the amphibolites, they are formed from sub-alkaline andesite-basalt with a tholeiitic affinity. TiO2 content of the analyzed amphibolite samples is mainly less than 1%, indicating an E-MORB original character for the magma. Major and trace element geochemistry of the studied rocks indicate a volcanic arc setting for the rocks. Chemistry …

A Function-To-Task Process Model For Adaptive Automation System Design, Jason M. Bindewald, Michael E. Miller, Gilbert L. Peterson

Faculty Publications

Adaptive automation systems allow the user to complete a task seamlessly with a computer performing tasks at which the human operator struggles. Unlike traditional systems that allocate functions to either the human or the machine, adaptive automation varies the allocation of functions during system operation. Creating these systems requires designers to consider issues not present during static system development. To assist in adaptive automation system design, this paper presents the concept of inherent tasks and takes advantage of this concept to create the function-to-task design process model. This process model helps the designer determine how to allocate functions to the …

Raman Microspectroscopy For The Early Detection Of Pre-Malignant Changes In Cervical Tissue, Nosheen Rashid, Haq Nawaz, Kelvin W. Poon, Franck Bonnier, Salih Bakhiet, Cara Martin, John O'Leary, Hugh Byrne, Fiona Lyng

Articles

Cervical cancer is the third most common cancer affecting women worldwide. The mortality associated with cervical cancer can, however, be significantly reduced if the disease is detected at the pre-malignant stage. The aim of this study was to evaluate the potential of Raman microspectroscopy for elucidation of the biochemical changes associated with the pre-malignant stages of cervical cancer. Formalin fixed paraffin preserved tissue sections from cervical biopsies classified as negative for intraepithelial lesion and malignancy (NILM), low grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL) were analysed by Raman spectral mapping. Raman mapping, with K-Means Cluster …

Lacustrine Turbidites From Tropical African Lakes As Indicators Of Hydrologic And Climatic Changes, Xuewei Zhang

Dissertations - ALL

Flood-sourced turbidites (i.e. hyperpycnites) preserved in lake basins are proven indicators of hydrologic changes, yet their usefulness as recorders of tropical paleoclimate variability has long been overlooked. The primary focus of this dissertation research is to investigate the late Quaternary hydroclimatic changes in tropical Africa, using hyperpycnites, dated sediment cores, and high-resolution seismic reflection profiles from Lake Kivu in the East African Rift and Lake Bosumtwi in equatorial West Africa. A secondary focus of this dissertation is to image ancient turbidite systems of the Lake Albert rift in East Africa, using 2-D and 3-D seismic reflection data, and to assess …

A Pareto-Frontier Analysis Of Performance Trends For Small Regional Coverage Leo Constellation Systems, Christopher Alan Hinds

Master's Theses

As satellites become smaller, cheaper, and quicker to manufacture, constellation systems will be an increasingly attractive means of meeting mission objectives. Optimizing satellite constellation geometries is therefore a topic of considerable interest. As constellation systems become more achievable, providing coverage to specific regions of the Earth will become more common place. Small countries or companies that are currently unable to afford large and expensive constellation systems will now, or in the near future, be able to afford their own constellation systems to meet their individual requirements for small coverage regions.

The focus of this thesis was to optimize constellation geometries …

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …

Novel Analytical Tools For Studies In Molecular Assemblies : I. Electro-Active Single-Mode Integrated Optical Waveguides ; Ii. Coupled Plasmon Waveguide Resonances., Xue Han

Electronic Theses and Dissertations

Two optical analytical tools were developed for studying molecular assemblies at solid/liquid interfaces. Electro-active single-mode integrated optical waveguide (EA-SM-IOW) technology was developed as a platform for spectroelectrochemical investigations on redox adsorbates at the sub-monolayer level. With an optimized ultra-thin indium tin oxide film combined with a single-mode integrated optical waveguide, for the first time, a more than 14,000 times higher sensitivity (compared to conventional potential-modulated transmittance) was achieved. From optical signals, this technique was able to reconstruct electrochemical information of redox adsorbates, including the formal potential and the electron transfer rate. A few major advantages were achieved with the developed …

Biomarker Discovery Of Liver Diseases Using Mass Spectrometry-Based Metabolomics., Xue Shi

Electronic Theses and Dissertations

Metabolomics has emerged as one of the latest of the "-omics" disciplines that can detect metabolite biomarkers in biological samples. The diverse characteristics of metabolites make the analytical platform challenging in metabolomics. Two bioanalytical platforms were developed in this study to investigate metabolite abundance changes under different biological conditions. We first developed a bioanalytical platform that coupled linear trap quadruple - Fourier transform ion cyclotron mass spectrometer (LTQ-FTICR MS) with direct infusion chip-based nano-electrospray ionization (DI-nESI) and applied it to study polychlorinated biphenyls (PCB) effects on non-alcoholic fatty liver disease (NAFLD). We also employed this platform in conjunction with in …

Thermionic Emission Properties Of Novel Carbon Nanostructures., Andriy Sherehiy

Electronic Theses and Dissertations

Materials with low work function values (< 2 eV) are highly in demand for low temperature thermionic electron emission, which is a key phenomenon for waste heat recovery applications. Here we present the study of the thermionic emission of the hybrid structure phosphorus, (P) doped diamond nano crystals grown on conical carbon nanotubes (CCNTs). The CCNTs provide the conducting backbone for the P-doped diamond nanocrystals. In the first part of this thesis thermionic emission properties of conical carbon nanotubes (CCNTs) grown on platinum wires and planar graphite foils were investigated. The work function (Φ) values extracted from the thermionic emission data range from 4.1 to 4.7 eV. The range of Φ values is attributed to the morphological characteristics, such as tip radius, aspect ratio, density, and wall structure of CCNTs. The observed lower values for Φ are significantly smaller than that of multi-walled carbon nanotubes (MWNTs). The reduced Φ values are attributed to field penetration effect as a result of the local field enhancement from these structures having high aspect ratio and an excellent field enhancement factor. The high amplification of the external field at the apex of the nanostructures is capable of reducing both the barrier height and the width, in turn contributing to the improved emission current at lower temperatures. The ultraviolet photoemission spectroscopy data of CCNTs grown on Pt wires are in reasonable agreement with the thermionic emission data. In the next part of the thesis we present work function reduction of phosphorus (P) doped (i) diamond nanocrystals grown on conical carbon nanotubes (CCNTs) and (ii) diamond films grown on silicon substrates. Thermionic emission measurements from phosphorus doped diamond crystals on CCNTs resulted in work function value of 2.23 eV. The reduced work-function is interpreted as due to the presence of the surface states and midband-gap states and no evidence for negative electron affinity was seen. However, Ultraviolet photo-spectroscopy studies on phosphorus doped diamond films yielded a work function value of ~1.8 eV with a negative electron affinity (NEA) value of 1.2 eV. Detailed band diagrams are presented to support the observed values for both cases. In addition we determined the work function values of nanocrystalline P doped diamond films grown on W foil to be significantly lower, 1.0- 1.33 eV compared to the hybrid structure and polycrystalline film on Si substrates. We studied tungsten (W) nanowires as an alternative material in place of CCNT as the supporting and conducting channel for P doped diamond crystals in a new hybrid structure. We described the process of fabrication of arrays of vertical W nanowires by microwave plasma treatment and synthesis of P doped nanocrystalline diamond on top of the reduced W nanowires. Thermionic emission measurements from the alternative hybrid structure resulted in high value of the work function ~ 5.1 eV.

The Use Of Variable-Bagging And The Cross-Validation Selector In The Prediction Of Alzheimer’S Using The Adni Database., Michael Wayne Godbey

Electronic Theses and Dissertations

Dimensionality plays a huge part in the modeling process. If there are more elements in a data set than variables in each element then there are very few restrictions in selection of an algorithm. Bagging, bootstrap aggregating (Breiman, 1994), may also be used to improve a model’s prediction capability. On the other hand, if there more variables in each observation than the number of observations in the dataset, the number of usable algorithms is greatly reduced. The recently developed algorithm, support vector machines, was designed for such situations, in comparison to algorithms such as logistic regression which have instability issues …

Synthesis And Characterization Of Ln[Hfac]X And Ln[Fod]X Complexes For Thermochromatographic Separations, Matthew L. Marsh

Chancellor’s Honors Program Projects

No abstract provided.

The Phenomenon Of Outbound Medical Tourism In The United States, Tanner Douglas Cabbage

Chancellor’s Honors Program Projects

No abstract provided.

Neutron Study Of Structure And Dynamics Of Rigid Polymers, Naresh Osti

All Dissertations

The structure and the dynamics in two different classes of rigid polymers; ionomers and rigid luminescent polymers, have been investigated predominantly by neutron techniques. Rigidity of the backbones of both polymers affects their properties. For ionomers, it affects transport pathways, therefore, their applications for energy and separation membranes. In luminescent polymers, it determines the conformations of the chains and their electro-optical response. One group of the polymers consists of rigid hydrophobic para-phenylene backbone decorated with pendant phenyl side chains functionalized with sulfonic acid (SPP). The other family of polymers consists of poly para-phenyleneethynylene (PPE) backbone that becomes conjugated upon conformational …

Method Development For The Analysis Of Aluminum, Calcium, Magnesium And Iron In Sedimentary Rocks, Zainab Ali Alhawdar

Electronic Theses & Dissertations

The focus of this study involved the analysis of sedimentary rocks by using atomic absorption spectroscopy. There are three classifications of sedimentary rocks: organic, formed as a result of vital activity of organisms such as coal; non-organic (chemical), formed in the process of evaporation of concentrated mineral solution such as limestone, dolomite, gypsum, salt and chert; and clastic (fragmental), formed from pre-existing rocks as a result of their fragmentation followed by further hardening and cementing such as conglomerate, breccia, sandstone, siltstone and shale. There are various analytical methods for analyzing sedimentary rocks, all of which require dissolving and digestion of …

Aspccgtk: Towards Syntactic Parsing With Semantic Disambiguation, Yuliya Lierler, Peter Schueller

Computer Science Faculty Publications

Natural language expressions are often ambiguous, allowing multiple interpretations. In this note we describe an approach that integrates syntactic analysis with semantic constraints in a system called ASPCCGTK. This system is based on Answer Set Programming — a popular declarative constraint programming paradigm.

Ogden College Of Science & Engineering Newsletter (Winter 2014), Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

The Development Of A Laminated Copolyester Electric Guitar, Addison S. Karnes

Electronic Theses and Dissertations

This thesis is an investigation of the fabrication and assembly methodologies employed in the development of a proof-of-principle prototype electric guitar composed of laminated copolyester. The objective of the project was to develop the processes and procedures to create an optimized physical and visual bond between layers to minimize vibratory dissipation, thus maximizing sustain. A high speed CNC router, abrasive waterjet, laser engraver-cutter, as well as various manual fabrication and assembly methods were investigated in the construction of the guitar prototypes. The lamination processes explored include low-temperature, heat-assisted pressure bonding, solvent and chemical welding, and contact adhesives. The project concluded …

Oxidative Damage To Dna 2´-Deoxyribose By Carbonate Radicals: Reaction Mechanisms And Products, Terence J. Moore

Electronic Theses and Dissertations

The carbonate radical anion (CO₃^•-, CR) is an important reactive oxygen species produced in vivo by one-electron oxidation of CO₂ or bicarbonate, constituents of the major physiological buffer. It was demonstrated for the first time by using an HPLC-based analysis of low-molecular products of DNA damage that CRs react with DNA 2΄-deoxyribose by the hydrogen abstraction mechanism. CRs exhibit a ~ 800-fold preference for one-electron oxidation of guanine over hydrogen abstraction from DNA sugar, in sharp contrast with •OH. CRs also have, as compared to •OH, an increased preference for the H1΄ abstraction, which is the …

Underwater God Rays From A Custom Volume Renderer, Gowthaman Ilango

All Theses

Peanut Butter Jelly, directed by Alexander Beaty, is a 51 second computer-animated short film produced by Digital Production Arts. The plot focuses on a fight sequence between a pirate jelly fish and a flyboy jelly fish over a peanut butter jar. The production demanded a photo-realistic computer generated underwater environment, which lead to the need for a custom built volume renderer to render high quality god rays. This thesis illustrates the requirement for a customized volume renderer for the production, the algorithm, and the implementation of the renderer. It also describes a tool created for Maya 2012 which gives the …

Scientific Application Acceleration Utilizing Heterogeneous Architectures, Edwin Weill

All Theses

Within the past decade, there have been substantial leaps in computer architectures to exploit the parallelism that is inherently present in many applications. The scientific community has benefited from the emergence of not only multi-core processors, but also other, less traditional architectures including general purpose graphical processing units (GPGPUs), field programmable gate arrays (FPGAs), and Intel's many integrated cores (MICs) architecture (i.e. Xeon Phi). The popularity of the GPGPU has increased rapidly because of their ability to perform massive amounts of parallel computation quickly and at low cost with an ease of programmability. Also, with the addition of high-level programming …

Fast Fission Neutron Detection Using The Cherenkov Effect, Matthew Millard

All Theses

The Cherenkov effect in optically clear media of varying indices of refraction and composition was investigated for quantification of fast neutrons. The ultimate application of the proposed detection system is criticality monitoring. The optically clear medium, composed of select target nuclei, was coupled to a photomultiplier tube. Neutron reaction products of the target nuclei contained within the optical medium emit beta particles and gamma rays that produce Cherenkov photons within the medium which can be detected. Assessed media include quartz (SiO2), sapphire (Al2O3), spinel (MgAl2O4), and zinc sulfide (ZnS), which were irradiated with un-moderated 252Cf. Monte Carlo N-Particle (MCNP) code …

Issues Of Social Data Analytics With A New Method For Sentiment Analysis Of Social Media Data, Zhaoxia Wang, Victor J. C. Tong, David Chan

Research Collection School of Social Sciences

Social media data consists of feedback, critiques and other comments that are posted online by internet users. Collectively, these comments may reflect sentiments that are sometimes not captured in traditional data collection methods such as administering a survey questionnaire. Thus, social media data offers a rich source of information, which can be adequately analyzed and understood. In this paper, we survey the extant research literature on sentiment analysis and discuss various limitations of the existing analytical methods. A major limitation in the large majority of existing research is the exclusive focus on social media data in the English language. There …

Phenology And Effects Of Dams On The Success Of Atlantic Salmon Smolt Migrations In The Penobscot River, Maine, Daniel S. Stich

Electronic Theses and Dissertations

Atlantic salmon Salmo salar populations are diminished throughout their range and high marine mortality is among the drivers of the failure of many stocks to recover. A goal of salmon recovery is to maximize the number of juvenile ‘smolts’ entering the ocean to offset loss therein. Dam removals and changes to hydropower allocation in Maine’s largest river, the Penobscot River, have occurred as part of the Penobscot River Restoration Project (PRRP). These activities, in addition to stocking have the potential to influence the number of smolts reaching the ocean. Telemetry was used to investigate factors influencing initiation of migratory behavior, …

An Optimization Method For Estimating Joint Parameters Of The Hip And Knee, Ben Tesch

Theses and Dissertations

Biomechanics, generally speaking, concerns the application of engineeringprinciples to the study of living things. This work is concerned withhuman movement analysis, a subfield of biomechanics, where the methodsof classical mechanics are applied to human movement. This field hascontributed to the general understanding of human movement, and itstechniques are used in the diagnosis and treatment of disease. Centralto the field is the process of measuring human movement. Since classicalmechanics deals with the motion of rigid bodies, and ideal measurementsystem would be able to accurately record the exact pose --- combinedposition and orientation --- of the bones. The techniques that reachthis ideal …