Physical Sciences and Mathematics Commons^™

Electrical Characterization Of Irradiated Semiconducting Amorphous Hydrogenated Boron Carbide, George Glen Peterson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Semiconducting amorphous partially dehydrogenated boron carbide has been explored as a neutron voltaic for operation in radiation harsh environments, such as on deep space satellites/probes. A neutron voltaic device could also be used as a solid state neutron radiation detector to provide immediate alerts for radiation workers/students, as opposed to the passive dosimetry badges utilized today. Understanding how the irradiation environment effects the electrical properties of semiconducting amorphous partially dehydrogenated boron carbide is important to predicting the stability of these devices in operation. p-n heterojunction diodes were formed from the synthesis of semiconducting amorphous partially dehydrogenated boron carbide on silicon …

Estimation Of The Three Key Parameters And The Lead Time Distribution In Lung Cancer Screening., Ruiqi Liu

Electronic Theses and Dissertations

This dissertation contains three research projects on cancer screening probability modeling. Cancer screening is the primary technique for early detection. The goal of screening is to catch the disease early before clinical symptoms appear. In these projects, the three key parameters and lead time distribution were estimated to provide a statistical point of view on the effectiveness of cancer screening programs. In the first project, cancer screening probability model was used to analyze the computed tomography (CT) scan group in the National Lung Screening Trial (NLST) data. Three key parameters were estimated using Bayesian approach and Markov Chain Monte Carlo …

A Theoretical Analysis On The Zintl-Klemm Concept And Its Extensions, Sandra Maria Simon

Theses and Dissertations

The desire to rationalize and explain the complex structures that form in solid states has motivated many to explore collections of structures with similar topologies but with differing compositions in order to determine whether or not similar chemical bonding was responsible for the structures. The Zintl-Klemm Concept, the Extended Zintl-Klemm Concept Model-1, and the Extended Zintl-Klemm Concept Model-2 attempt to rationalize and predict the structure of a group of intermetallics, referred to as Zintl Compounds, and their oxides based on simple electron counting schemes and with the introduction of pseudo-atoms.

This study looks at the electronic structure of a set …

Mineral And Bioclimatic Factors Controlling Soil Black Carbon Sequestration Potential Along An Elevational Gradient, Adam Fernandez

Theses, Dissertations and Culminating Projects

Black carbon (BC) is formed by the incomplete combustion of fossil fuels, biofuels, and biomass. It has been suggested due to its ubiquitous nature in soils that BC may act as a significant sink in the global carbon cycle. BC has been widely studied in a variety of soil and sediment types but spodosols (acid forest soils) have been underrepresented in the literature. In the present study, spodosol soil samples were collected along an elevational gradient (~500 to 1,200 m) from three different mountains in the White Mountain National Forest of New Hampshire. Total soil carbon was first measured using …

Watershed Sub-Basin Scale Forest Fire Impacts On Soil Chemistry : A Case Study In Delaware State Forest, Pennsylvania, Usa, Jason Scott Darley

Theses, Dissertations and Culminating Projects

Forest fires can affect soil chemistry and soil properties depending on the fire intensity and type of biomass burned, changing the local environment. For this study, soil and ash samples were examined post-fire from the 16-Mile fire event in the Delaware State Forest, Pennsylvania, to understand the pedosphere chemistry within the watershed subbasin. The main goal of this project was to study the major and trace elements of ash and soil samples of the 16-Mile Fire in the burned area and compare to samples upstream and downstream of the watershed sub-basin. Inductively coupled plasma mass spectroscopy was conducted for major …

Large Marine Protected Areas Represent Biodiversity Now And Under Climate Change, T. E. Davies, S. M. Maxwell, K. Kaschner, C. Garilao, N. C. Ban

Biological Sciences Faculty Publications

Large marine protected areas (>30,000 km²) have a high profile in marine conservation, yet their contribution to conservation is contested. Assessing the overlap of large marine protected areas with 14,172 species, we found large marine protected areas cover 4.4% of the ocean and at least some portion of the range of 83.3% of the species assessed. Of all species within large marine protected areas, 26.9% had at least 10% of their range represented, and this was projected to increase to 40.1% in 2100. Cumulative impacts were significantly higher within large marine protected areas than outside, refuting the …

Mantle Dynamics Beneath The Discrete And Diffuse Plate Boundaries Of The Juan De Fuca Plate: Results From Cascadia Initiative Body Wave Tomography, Joseph S. Byrnes, Douglas R. Toomey, Emilie E. E. Hooft, John Nábělek, Jochen Braunmiller

School of Geosciences Faculty and Staff Publications

We use the delay times of teleseismic S phases recorded by ocean bottom seismometers during the plate‐scale Cascadia Initiative community experiment to constrain the heterogeneity of seismic velocity structure beneath young oceanic lithosphere. Our study area covers the entire Juan de Fuca (JdF) and Gorda plates, from their creation at the JdF and Gorda Ridges to their subduction beneath the North American continent, and the entire length of the Blanco transform fault. The range of the observed Vs anomalies requires variations in the melt fraction of the asthenosphere. The data require that low Vsanomalies extend to depths of at …

Sedimentary Characteristics And Nutrient Sequestration Of Embanked Floodplains Along The Lower Mississippi River, Mississippi And Louisiana, R M Malitha Rathnayake

Master's Theses

The Mississippi River Basin is the largest river basin in North America and the third largest river basin in the world. Most of the corn, soybeans, wheat, cattle, and hogs harvested in the United States come from the Mississippi River Basin and about 58% of the entire drainage basin is croplands. Runoff from these lands carries sediments and nutrients, and the Mississippi River transports these downstream and ultimately deposits them in the Gulf of Mexico. The northern Gulf of Mexico is one of largest human-caused hypoxic zones in the world. Hypoxia is the phenomena where the dissolved oxygen level decreases …

Environmentally-Driven Variation In The Population Dynamics Of Gulf Menhaden (Brevoortia Patronus), Grant D. Adams

Master's Theses

Gulf Menhaden (Brevoortia patronus) is an abundant forage fish distributed throughout the Northern Gulf of Mexico (NGOM). Gulf Menhaden support the second largest fishery, by weight, in the United States and represent a key linkage between upper and lower trophic levels. Variation in the population dynamics can, therefore, pose consequences for the ecology and economy in the NGOM. Here we aim to understand variation in the individual and population dynamics of Gulf Menhaden throughout ontogeny and how such variation relates to environmental processes. We utilized a suite of fishery-dependent and –independent, remote sensing, modeled, and in situ data …

Eignefunctions For Partial Differential Equations On Two-Dimensional Domains With Piecewise Constant Coefficients, Abdullah Muheel Momit Aurko

Master's Theses

In this thesis, we develop a highly accurate and efficient algorithm for computing the solution of a partial differential equation defined on a two-dimensional domain with discontinuous coefficients. An example of such a problem is for modeling the diffusion of heat energy in two space dimensions, in the case where the spatial domain represents a medium consisting of two different but homogeneous materials, with periodic boundary conditions.

Since diffusivity changes based on the material, it will be represented using a piecewise constant function, and this results in the formation of a complicated mathematical model. Such a model is impossible to …

Interaction With Nitric Oxide Of The Nitrosomonas Europaea Tetraheme Protein Cytochrome C554, And Two Of Its Variants, In Increasingly Reducing Environments, Jennifer M. Mcgarry

Theses and Dissertations

A re-investigation of the interaction with NO of the small tetraheme protein cytochrome c554 (C554) from Nitrosomonas europaea has shown that the 5-coordinate heme II of the 2-electron or 4-electron reduced protein will nitrosylate reversibly. The nitrosylation process was found to be first order in C554, first-order in NO, and second-order overall. The rate constant for NO binding to the heme was determined to be 3000 ± 140 M-1s-1, while the rate constant for dissociation was 0.034 ± 0.009 s-1; the degree of protein reduction does not appear to significantly influence the nitrosylation rate. In contrast to a previous report, …

Modeling Gravitational-Wave Sources For Pulsar Timing Arrays, Joseph Simon

Theses and Dissertations

The recent direct detections of gravitational waves (GWs) from merging black holes by the Laser Interferometer Gravitational-wave Observatory (LIGO) marks the beginning of the era of GW astronomy and promises to transform fundamental physics. In the coming years, there is hope for detections across the mass scale of binary black holes.

Pulsar Timing Arrays (PTAs) are galactic-scale low-frequency (nHz - $\mu$Hz) GW observatories, which aim to directly detect GWs from binary supermassive black holes (SMBHs) ($\gtrsim 10^{7} \msun$). The frequency and black hole mass range that PTAs are sensitive to is orders of magnitude different from those LIGO is observing, …

Galactic Outflows And Their Correlations With Galaxy Properties At 0.8 < Z < 1.6, Lindsey Whiting

Theses and Dissertations

Out

ows have been shown to be ubiquitous in galaxies between z = 1 and z=2,

and many models and observations have attempted to correlate the absorption line

properties of these out

ows with morphological characteristics of their host galaxies.

In this study, we examined the spectra of 71 galaxies with redshifts 1< z<2, paying

particular attention to the FeII and MgII absorption lines. We plotted the equivalent

width, velocity, and maximum velocity of the absorption features against various

physical properties of the galaxies, obtained from catalogues created by Skelton et

al., (2014) and van der Wel et al., (2012). We conrmed …

Characterizing The Low Net-To-Gross, Fluviodeltaic Dry Hollow Member Of The Frontier Formation, Western Green River Basin, Wyoming, Scott Romney Meek

Theses and Dissertations

The Frontier Formation in the Green River Basin of southwestern Wyoming consists of Late Cretaceous (Cenomanian-Turonian) marine and non-marine sandstones, siltstones, mudstones and coals deposited on the western margin of the Cretaceous Interior Seaway. Tight gas reservoirs exist in subsurface fluviodeltaic sandstones in the upper Frontier Formation (Dry Hollow Member) on the north-south trending Moxa Arch within the basin. These strata crop out in hogback ridges of the Utah-Idaho-Wyoming Thrust Belt approximately 40 km west of the crest of the Moxa Arch. Detailed, quantitative outcrop descriptions were constructed using emerging photogrammetric techniques along with field observations and measured sections at …

A Mathematical Model Of Hepatitis C Virus Infection Incorporating Immune Responses And Cell Proliferation, Huda Amer Hadi

Mathematics Theses

This thesis introduces a mathematical model of differential equations for the chronic hepatitis C virus (HCV) infection, which is a contagious disease that infects the liver cells. Firstly, we present the early mathematical models for the basic dynamics of virus infection that developed and analyzed to understand the dynamics of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and some other viruses. Next, we present the extended model of the basic HCV virus dynamics that incorporate the effectiveness of a treatment. After that, the mathematical model that includes proliferation terms for both infected and uninfected hepatocytes is discussed. Lastly, the …

Epigenetic Mechanism Of Regulation Of Hox Genes And Neurotransmitters Via Hormones And Lncrna, Paromita Deb

Chemistry & Biochemistry Dissertations

Endocrine disrupting chemicals (EDCs) are classes of environmental contaminants whose exposure even at very low concentrations interfere with normal endocrine signaling and induce many adverse health effects including increased risk of birth defects, diabetes, obesity, abnormal reproduction, and cancer. EDC exposure alters the epigenetic programming of cells resulting in altered gene expression and regulation and cell signaling. These EDCs include bisphenol-A (BPA), diethylstilbesterol (DES), polychlorinated biphenyl (PCB), phthalates, phytoestrogens, methoxychlor, fungicides, insecticide, herbicide, and some heavy metals. As a part of my work, I have investigated epigenetic impacts of EDCs on HOX (homeobox containing genes) genes, which are critical players …

A Study On Traveling Wave Solutions In The Shallow-Water-Type System, Ting Luo

Mathematics Dissertations

The study of water waves reveals the physical principles of many phenomena of scientific and engineering interest. In this dissertation I consider three models: two-component Camassa-Holm system(2CH), generalized two-component Camassa-Holm equation(g2CH) and rotation-Camassa-Holm equation(R-CH). In the first part, we consider the stability of the Camassa-Holm peakons and antipeakons in the dynamics of the two-component Camassa-Holm system. The second part shows that the train of $N$-smooth traveling waves of this system is dynamically stable to perturbations in energy space with a range of parameters. In the third part, we formally derive the simplified phenomenological models with the Coriolis effect due to …

Renewed Significance Of Ras Gtpases, Michael Wey

Chemistry & Biochemistry Dissertations

The Ras superfamily of GTPases act as molecular switches and play a critical role in intracellular signal transduction. These GTPases cycle between an active GTP- bound form and an inactive GDP-bound form to regulate a myriad of cellular processes. However, this classical model of Ras regulation does not accurately project the entire picture of Ras regulation. This work discusses non-classical and newly discovered elements of the Ras signaling network. While intrinsic kinetic properties of Ras are included in the classical model of Ras regulation, the importance of them is understated. We show that the development Costello Syndrome from somatic Harvey …

Digital Anti-Forensics: An Implementation And Examination, Stephanie Dachs

Student Theses

The rise of computer use and technical adeptness by the general public in the last two decades are undeniable. With greater use comes a greater possibility for misuse, evidenced by today’s incredible number of crimes involving computers as well as the growth in severity from that of cyber hooliganism to cyber warfare. Although frequently utilized for privacy and security purposes, the vast range of anti-forensic techniques has contributed to the ability for hackers and criminals to obstruct computer forensic investigations.

Understanding how anti-forensics may alter important and relevant data on an electronic device will prove useful for the success and …

Real-Time Influence Maximization On Dynamic Social Streams, Yanhao Wang, Qi Fan, Yuchen Li, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

Influence maximization (IM), which selects a set of k users(called seeds) to maximize the influence spread over a social network, is a fundamental problem in a wide range of applications such as viral marketing and network monitoring.Existing IM solutions fail to consider the highly dynamic nature of social influence, which results in either poor seed qualities or long processing time when the network evolves.To address this problem, we define a novel IM query named Stream Influence Maximization (SIM) on social streams.Technically, SIM adopts the sliding window model and maintains a set of k seeds with the largest influence value over …

Online Multitask Relative Similarity Learning, Shuji Hao, Peilin Zhao, Yong Liu, Steven C. H. Hoi, Chunyan Miao

Research Collection School Of Computing and Information Systems

Relative similarity learning (RSL) aims to learn similarity functions from data with relative constraints. Most previous algorithms developed for RSL are batch-based learning approaches which suffer from poor scalability when dealing with real world data arriving sequentially. These methods are often designed to learn a single similarity function for a specific task. Therefore, they may be sub-optimal to solve multiple task learning problems. To overcome these limitations, we propose a scalable RSL framework named OMTRSL (Online Multi-Task Relative Similarity Learning). Specifically, we first develop a simple yet effective online learning algorithm for multi-task relative similarity learning. Then, we also propose …

On Syntropy & Precognitive Interdiction Based On Wheeler-Feynman’S Absorber Theory, Florentin Smarandache, Victor Christianto, Yunita Umniyati

Branch Mathematics and Statistics Faculty and Staff Publications

It has been known for long time that intuition plays significant role in many professions and human life, including in entrepreneurship, government, and also in detective or law enforcement activities. Women are known to possess better intuitive feelings or “hunch” compared to men. Despite these examples, such a precognitive interdiction is hardly accepted in established science. In this letter, we discuss briefly the advanced solutions of Maxwell equations, and then explore plausible connection between syntropy and precognition.

Uses Of The Hypergeometric Distribution For Determining Survival Or Complete Representation Of Subpopulations In Sequential Sampling, Brooke Busbee

Electronic Theses and Dissertations

This thesis will explore the hypergeometric probability distribution by looking at many different aspects of the distribution. These include, and are not limited to: history and origin, derivation and elementary applications, properties, relationships to other probability models, kindred hypergeometric distributions and elements of statistical inference associated with the hypergeometric distribution. Once the above are established, an investigation into and furthering of work done by Walton (1986) and Charlambides (2005) will be done. Here, we apply the hypergeometric distribution to sequential sampling in order to determine a surviving subcategory as well as study the problem of and complete representation of the …

Database Management System For Byuh Jonathan Napela Center, Olivia K. F. Moleni

Masters Theses & Doctoral Dissertations

The purpose of this project is to build a database management system (DBMS) for the Jonathan Napela Center department. The Napela Center is a department for students who are majoring or minoring in Hawaiian Studies and/or Pacific Island Studies. Currently the Napela Center uses Microsoft Excel as their DBMS to store and track both current and past student information. Unfortunately, this system hasn’t been working well for them due to unreliable information, limited user access and sometime can get too complex with too much data. So the director of the department decided to seek for another system.

This paper will …

Numerical Methods For Non-Divergence Form Second Order Linear Elliptic Partial Differential Equations And Discontinuous Ritz Methods For Problems From The Calculus Of Variations, Stefan Raymond Schnake

Doctoral Dissertations

This dissertation consists of three integral parts. Part one studies discontinuous Galerkin approximations of a class of non-divergence form second order linear elliptic PDEs whose coefficients are only continuous. An interior penalty discontinuous Galerkin (IP-DG) method is developed for this class of PDEs. A complete analysis of the proposed IP-DG method is carried out, which includes proving the stability and error estimate in a discrete W^2;p-norm [W^2,p-norm]. Part one also studies the convergence of the vanishing moment method for this class of PDEs. The vanishing moment method refers to a PDE technique for approximating these PDEs by a …

Ged: Moving Into The Electronic Age, Kateri Montileaux

Masters Theses & Doctoral Dissertations

The purpose of this study is to find a direction as the Community Continuing Education/General Education Diploma (CCE/GED) department goes into the electronic age. Not only has the General Education Diploma test become computer based, the process of studying, preparing and communicating has also required one to use desktop computers, laptops, tablets, smart phones, email, and webinars daily. The goal is to promote the department and its services to the younger generation (18-25 years old) who are completely comfortable using electronic devices, and to the older generation (40+years) who may know a little bit of electronic communicating but who are …

Seeing Through The Same Lens: Introspecting Guest Address Space At Native Speed, Siqi Zhao, Xuhua Ding, Wen Xu, Dawu Gu

Research Collection School Of Computing and Information Systems

Software-based MMU emulation lies at the heart of out-of-VM live memory introspection, an important technique in the cloud setting that applications such as live forensics and intrusion detection depend on. Due to the emulation, the software-based approach is much slower compared to native memory access by the guest VM. The slowness not only results in undetected transient malicious behavior, but also inconsistent memory view with the guest; both undermine the effectiveness of introspection. We propose the immersive execution environment (ImEE) with which the guest memory is accessed at native speed without any emulation. Meanwhile, the address mappings used within the …

A Study On The Nonlocal Shallow-Water Model Arising From The Full Water Waves With The Coriolis Effect, Junwei Sun

Mathematics Dissertations

The Equatorial Undercurrent is a significant feature of the geophysical waves near the equator, which is one of the key factors to explain El Niño phenomenon. However, based on β-plane approximation, the classical theory of geophysical waves ignored the vertical structure of the Equatorial Undercurrent. To obtain a better description of the equatorial waves, in this dissertation, I study the rotational-Camassa-Holm (R-CH) equation, which is a mathematical model of long-crested water waves near the equator, propagating mainly in one direction with the effect of Earth's rotation under the f-plane approximation. R-CH equation can be derived by following the formal asymptotic …

Stability Study On Shear Flow And Vortices In Late Boundary Layer Transition, Jie Tang

Mathematics Dissertations

Turbulence is still an unsolved scientific problem, it has been regarded as “the most important unsolved problem of classical physics”. Dr. Liu proposed a new mechanism about turbulence generation and sustenance after decades of research on turbulence and transition. His new idea challenged the classical theorem in many aspects. One of them is the flow stability of transition. Dr. Liu believes that inside the flow field, shear (dominant in laminar) is very unstable while rotation (dominant in turbulence) is relative stable. This inherent property of flow creates the trend that non-vertical vorticity must transfer to vertical vorticity, and causes the …

High Order Dns For Vortex Structure In Late Flow Transition, Yong Yang

Mathematics Dissertations

Turbulence is still a world puzzle after over one hundred years research, and the current and classical theories brim with self-contradictions. C. Liu proposed a new theory on turbulence generation and structure after 28 years research, which are consistent without self-contradictions and well explain turbulence generation and structure. Based on this new theory, this dissertation (1) gives some mathematical explanations for new vortex identify method – Ω method; (2) analyzes the instability of shear layer by applying Chebyshev spectrum method to solve Orr-Sommerfeld eigenvalue equation; (3) investigates the vortex structure development in late flow transition; (4) utilizes the proper orthogonal …