Physical Sciences and Mathematics Commons^™

B3: Paleo-Dunes And Other Post-Glacial Oddities In The Woods And Fields Of New Sharon And Chesterville, Me, Patricia M. Millette, Benjamin Andrews, Anna Glass, Thaddeus Gunther, Roshan Luick

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 161-176.

B5: Geology Of The Lower Ellis River Valley And Rumford Whitecap Mountain, Andover And Rumford, Maine, Lindsay J. Spigel, Amber T.H. Whittaker, Ryan P. Gordon

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 197-216.

B1: Geology Of The Bald Mountain-Saddleback Wind Range, West-Central Maine, Douglas N. Reusch, Jake Hansen

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 119-134.

B2: Glacial Deposits And Late-Glacial To Postglacial Alluvial Fans In The Northwestern White Mountains, New Hampshire, Woodrow B. Thompson, Gregory Barker

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 135-160.

B6: Devonian Granite Melt Transfer In Western Maine: Relations Between Deformation, Metamorphism, Melting And Pluton Emplacement At The Migmatite Front, Gary S. Solar, Paul B. Tomascak, Michael Brown

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 217-246.

B4: Bedrock Geology Of Mt. Washington, Presidential Range, Nh, J. Dykstra Eusden, Brigit Anderson, Carlos Castro, Patrick Gardner, Chris Guiterman, Stephanie Higgins, Kelley Kugel, Adam Reid, Charles Rodda, Caitlin Tamposi

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 177-196.

Spellbinding Effects Of The Acidic Cooh-Terminus Of Factor Va Heavy Chain On Prothrombinase Activity And Function, Jamila Hirbawi, Michael Kalafatis

Chemistry Faculty Publications

Human factor Va (hfVa) is the important regulatory subunit of prothrombinase. Recent modeling data have suggested a critical role for amino acid Arg of hfVa for human prothrombin (hPro) activation by prothrombinase. Furthermore, it has also been demonstrated that hfVa has a different effect than that of bovine fVa on prethrombin-1 activation by prothrombinase. The difference between the two cofactor molecules was also found within the Asn-Arg dipeptide in the human factor V (hfV) molecule, which is replaced by the Asp-Glu sequence in bfV. As a consequence, we produced a recombinant hfV (rhfV) molecule with the substitution NR→DE. rhfV together …

Nanowire-Based Light-Emitting Diodes: A New Path Towards High-Speed Visible Light Communication, Mohsen Nami

Physics & Astronomy ETDs

Nano-scale optoelectronic devices have gained significant attention in recent years. Among these devices are semiconductor nanowires, whose dimeters range from 100 to 200 nm. Semiconductor nanowires can be utilized in many different applications including light-emitting diodes and laser diodes. Higher surface to volume ratio makes nanowire-based structures potential candidates for the next generation of photodetectors, sensors, and solar cells. Core-shell light-emitting diodes based on selective-area growth of gallium nitride (GaN) nanowires provide a wide range of advantages. Among these advantages are access to non-polar m-plane sidewalls, higher active region area compared to conventional planar structures, and reduction of threading …

Detecting Majorana Fermion Induced Crossed Andreev Reflection, Lei Fang

Dissertations, Theses, and Capstone Projects

This dissertation is devoted to a study of detecting the Majorana fermion induced crossed Andreev reflection.

Majorana fermions are particles that constitute their own antiparticles. In condensed matter physics, Majorana fermions are zero energy modes that reside at edges or around vortices of topological superconductors. The special properties of Majorana fermions result in their potential to conduct topological quantum computation, which has been attracting a lot of current research. One of the most important issues in the field of the Majorana fermion physics now is to detect their existence in realistic systems. Among many classes of detecting methods, a transport …

Parabolic Classical Curvature Flows, Brendan Guilfoyle, Wilhelm Klingenberg

Publications

We consider classical curvature flows: 1-parameter families of convex embeddings of the 2-sphere into Euclidean 3-space, which evolve by an arbitrary (nonhomogeneous) function of the radii of curvature (RoC). We determine conditions for parabolic flows that ensure the boundedness of various geometric quantities and investigate some examples. As a new tool, we introduce the RoC diagram of a surface and its hyperbolic or anti-de Sitter metric. The relationship between the RoC diagram and the properties of Weingarten surfaces is also discussed.

Interstructure Lattices And Types Of Peano Arithmetic, Athar Abdul-Quader

Dissertations, Theses, and Capstone Projects

The collection of elementary substructures of a model of PA forms a lattice, and is referred to as the substructure lattice of the model. In this thesis, we study substructure and interstructure lattices of models of PA. We apply techniques used in studying these lattices to other problems in the model theory of PA.

In Chapter 2, we study a problem that had its origin in Simpson, who used arithmetic forcing to show that every countable model of PA has an expansion to PA^∗ that is pointwise definable. Enayat later showed that there are 2^ℵ₀ models with …

Exploring The Internal Statistics: Single Image Super-Resolution, Completion And Captioning, Yang Xian

Dissertations, Theses, and Capstone Projects

Image enhancement has drawn increasingly attention in improving image quality or interpretability. It aims to modify images to achieve a better perception for human visual system or a more suitable representation for further analysis in a variety of applications such as medical imaging, remote sensing, and video surveillance. Based on different attributes of the given input images, enhancement tasks vary, e.g., noise removal, deblurring, resolution enhancement, prediction of missing pixels, etc. The latter two are usually referred to as image super-resolution and image inpainting (or completion).

Image super-resolution and completion are numerically ill-posed problems. Multi-frame-based approaches make use of the …

Some Results In Combinatorial Number Theory, Karl Levy

Dissertations, Theses, and Capstone Projects

The first chapter establishes results concerning equidistributed sequences of numbers. For a given $d\in\mathbb{N}$, $s(d)$ is the largest $N\in\mathbb{N}$ for which there is an $N$-regular sequence with $d$ irregularities. We compute lower bounds for $s(d)$ for $d\leq 10000$ and then demonstrate lower and upper bounds $\left\lfloor\sqrt{4d+895}+1\right\rfloor\leq s(d)< 24801d^{3} + 942d^{2} + 3$ for all $d\geq 1$. In the second chapter we ask if $Q(x)\in\mathbb{R}[x]$ is a degree $d$ polynomial such that for $x\in[x_k]=\{x_1,\cdots,x_k\}$ we have $|Q(x)|\leq 1$, then how big can its lead coefficient be? We prove that there is a unique polynomial, which we call $L_{d,[x_k]}(x)$, with maximum lead coefficient under these constraints and construct an algorithm that generates $L_{d,[x_k]}(x)$.

Asymptotic Counting Formulas For Markoff-Hurwitz Tuples, Ryan Ronan

Dissertations, Theses, and Capstone Projects

The Markoff equation is a Diophantine equation in 3 variables first studied in Markoff's celebrated work on indefinite binary quadratic forms. We study the growth of solutions to an n variable generalization of the Markoff equation, which we refer to as the Markoff-Hurwitz equation. We prove explicit asymptotic formulas counting solutions to this generalized equation with and without a congruence restriction. After normalizing and linearizing the equation, we show that all but finitely many solutions appear in the orbit of a certain semigroup of maps acting on finitely many root solutions. We then pass to an accelerated subsemigroup of maps …

Toxic Gas Sensing On Nanoporous Carbons, Nikolina-Eleni Travlou

Dissertations, Theses, and Capstone Projects

Activated carbons, either synthetic, developed in our laboratory, or commercial, were prepared or further modified, in order to introduce specific heteroatoms such as oxygen, nitrogen and sulfur to their matrices. Chips coated with thin layers of the carbon samples were used for the sensing of gaseous ammonia. They were exposed to continuous cycles of various ammonia concentrations (10-500 ppm), and changes in normalized resistance were analyzed. In all cases linear responses were recorded and the chips reached sensitivities as high as 31%, which are comparable to those of modified graphene-based sensors. The applied specific surface chemical modifications were an effective …

Hash-Map-Eradicator: Filtering Non-Target Sequences From Next Generation Sequencing Reads, Jonathon Brenner, Catherine Putonti

Catherine Putonti

Contemporary DNA sequencing technologies are continuously increasing throughput at ever decreasing costs. Moreover, due to recent advances in sequencing technology new platforms are emerging. As such computational challenges persist. The average read length possible has taken a giant leap forward with the PacBio and Nanopore solutions. Regardless of the platform used, impurities within the DNA preparation of the sample - be it from unintentional contaminants or pervasive symbiots - remains an issue. We have developed a new tool, HAsh-MaP-ERadicator (HAMPER), for the detection and removal of non-target, contaminating DNA sequences. Integrating hash-based and mapping-based strategies, HAMPER is both memory and …

A Polyglot Approach To Bioinformatics Data Integration: A Phylogenetic Analysis Of Hiv-1, Steven Reisman, Thomas Hatzopoulous, Konstantin Läufer, George K. Thiruvathukal, Catherine Putonti

Catherine Putonti

As sequencing technologies continue to drop in price and increase in throughput, new challenges emerge for the management and accessibility of genomic sequence data. We have developed a pipeline for facilitating the storage, retrieval, and subsequent analysis of molecular data, integrating both sequence and metadata. Taking a polyglot approach involving multiple languages, libraries, and persistence mechanisms, sequence data can be aggregated from publicly available and local repositories. Data are exposed in the form of a RESTful web service, formatted for easy querying, and retrieved for downstream analyses. As a proof of concept, we have developed a resource for annotated HIV-1 …

A Polyglot Approach To Bioinformatics Data Integration: Phylogenetic Analysis Of Hiv-1, Steven Reisman, Catherine Putonti, George K. Thiruvathukal, Konstantin Läufer

Catherine Putonti

RNA-interference has potential therapeutic use against HIV-1 by targeting highly-functional mRNA sequences that contribute to the virulence of the virus. Empirical work has shown that within cell lines, all of the HIV-1 genes are affected by RNAi-induced gene silencing. While promising, inherent in this treatment is the fact that RNAi sequences must be highly specific. HIV, however, mutates rapidly, leading to the evolution of viral escape mutants. In fact, such strains are under strong selection to include mutations within the targeted region, evading the RNAi therapy and thus increasing the virus’ fitness in the host. Taking a phylogenetic approach, we …

Assessment Of Earthquake Site Amplification And Application Of Passive Seismic Methods For Improved Site Classification In The Greater Vancouver Region, British Columbia, Frederick Andrew Jackson

Electronic Thesis and Dissertation Repository

There is renewed interest to improve seismic microzonation mapping in Greater Vancouver, British Columbia (BC). We investigate local geology as the cause of observed variable ground shaking from the 2015 M 4.7 Vancouver Island earthquake. We observe high amplification at 4-6 Hz on thick sediment and the northern edge of the Fraser River delta, and disparities with current regional seismic microzonation mapping. Site amplification and shear-wave velocity (V_S) are assessed from the first borehole earthquake recordings in BC. We also perform ambient vibration analyses at 13 new locations in southwest BC to highlight suitability of passive seismic methods …

Petrophysical Investigations Of The Marathon Cu-Pge Deposit, Marathon, On, Hiruni Gunawardana

Electronic Thesis and Dissertation Repository

Drill core samples obtained from four mineralized zones of the Marathon Cu-PGE deposit in the Coldwell igneous complex have been investigated for their petrophysical characteristics. Remanent magnetization was used as a possible tool to reorient core samples but a drilling induced overprint magnetization dominated the record. Anisotropy of magnetic susceptibility was measured to provide a proxy for the petrofabric of samples obtained from oriented drill cores; a well-defined planar fabric was found to strike 177 and dip 25°W, with down-dip lineation, in excellent agreement with inferred magmatic flow direction based on 3D modeling of mineralized footwall troughs. Magnetite rich lithologies …

A3: Hydrogeology Of The Former Chlor-Alkali Facility Superfund Site And Downstream Bed Sediment Mercury Contamination In The Androscoggin River, Berlin, New Hampshire, James Degnan, Darryl Luce, Andrew Hoffman, Ann Chalmers

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 61-80.

A6: Stratigraphic And Structural Traverse Of Mount Moriah And The Wild River Wilderness Area, Tim Allen

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 105-118.

A5: Grafton Notch State Park: Glacial Gorges And Streams Under Pressure In The Mahoosic Range, Maine, Alice M. Doughty, Woodrow B. Thompson

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 95-104.

A2: Smalls Falls Revisted: A Journey Through A Paleozoic Sedimentary Basin, M. R. Van Baalen, Douglas N. Reusch, John F. Slack

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 35-60.

A4: Possible Post-Laurentide Cirque Glaciation In The Great Gulf Presidential Range, New Hampshire, Brian Fowler, Dulin Ian

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 81-94.

A1: Lithium-Boron-Beryllium Gem Pegmatites, Oxford Co., Maine: Havey And Mount Mica Pegmatites, William B. Simmons, Alexander U. Falster, Karen L. Webber, Myles M. Felch, Dwight C. Bradley

New England Intercollegiate Geological Conference 2017

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 1-34.

Guidebook For Field Trips In Western Maine And Northern New Hampshire, Beverly Johnson, J. Dykstra Eusden

New England Intercollegiate Geological Conference 2017

New England Intercollegiate Geological Conference, 109th Annual Meeting, September 29 - October 1, 2017, Bethel, Maine, 345 p, color.

Torrefaction Kinetics Of Hemp Hurds, An Emerging Agricultural Byproduct, In A Small Retort, Tel Jensen

Civil and Environmental Engineering Undergraduate Honors Theses

As knowledge concerning the consequences of unsustainable energy sources and agricultural practices grows, development of low-impact alternatives to both becomes more important. Sustainable sources of biomass offer solutions to both problems. This study characterized the reaction kinetics of torrefying an agricultural byproduct, the woody interior of hemp stems, or hurds. Torrefaction was carried out at 250 °C in small and simple retorts made of galvanized steel pipe. A first-order model most closely approximated the reaction. A sensitivity analysis was performed and the data was adjusted to correct for three potential sources of error, and regressed to find the best fit …

Spin-Imbalance In A 2d Fermi-Hubbard System, Peter Brown, Debayan Mitra, Elmer Guardado-Sanchez, Peter Schauß, Stanimir Kondov, Ehsan Khatami, Thereza Paiva, Nandini Trivedi, David Huse, Waseem Bakr

Faculty Publications

The interplay of strong interactions and magnetic fields gives rise to unusual forms of superconductivity and magnetism in quantum many-body systems. Here, we present an experimental study of the two-dimensional Fermi-Hubbard model—a paradigm for strongly correlated fermions on a lattice—in the presence of a Zeeman field and varying doping. Using site-resolved measurements, we revealed anisotropic antiferromagnetic correlations, a precursor to long-range canted order. We observed nonmonotonic behavior of the local polarization with doping for strong interactions, which we attribute to the evolution from an antiferromagnetic insulator to a metallic phase. Our results pave the way to experimentally mapping the low-temperature …

Lessons From Between The White Lines For Isolated Data Scientists, Benjamin Baumer

Mathematics Sciences: Faculty Publications

Many current and future data scientists will be “isolated”—working alone or in small teams within a larger organization. This isolation brings certain challenges as well as freedoms. Drawing on my considerable experience both working in the professional sports industry and teaching in academia, I discuss troubled waters likely to be encountered by newly minted data scientists and offer advice about how to navigate them. Neither the issues raised nor the advice given are particular to sports and should be applicable to a wide range of knowledge domains.