Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2017

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 11821 - 11850 of 12521

Full-Text Articles in Physical Sciences and Mathematics

Climate Fingerprints Of The Interdecadal Pacific Oscillation, Bo Dong Jan 2017

Climate Fingerprints Of The Interdecadal Pacific Oscillation, Bo Dong

Legacy Theses & Dissertations (2009 - 2024)

The Interdecadal Pacific Oscillation (IPO) is a multi-decadal quasi-oscillation seen primarily in tropical and extratropical Pacific sea surface temperatures (SSTs). Interacting with the atmosphere, the IPO has been shown to affect global and regional climate. However, a quantitative global synthesis of the IPO’s climate fingerprints and the underlying mechanisms are still lacking. Based on observational and reanalysis data and atmospheric model simulations, this dissertation investigates the IPO’s influence on regional climates over the globe, and its interactions with El Niño-Southern Oscillation (ENSO) and global warming.


Sensitivity Analysis Method To Address User Disparities In The Analytic Hierarchy Process, Marie Ivanco, Gene Hou, Jennifer Michaeli Jan 2017

Sensitivity Analysis Method To Address User Disparities In The Analytic Hierarchy Process, Marie Ivanco, Gene Hou, Jennifer Michaeli

Mechanical & Aerospace Engineering Faculty Publications

Decision makers often face complex problems, which can seldom be addressed well without the use of structured analytical models. Mathematical models have been developed to streamline and facilitate decision making activities, and among these, the Analytic Hierarchy Process (AHP) constitutes one of the most utilized multi-criteria decision analysis methods. While AHP has been thoroughly researched and applied, the method still shows limitations in terms of addressing user profile disparities. A novel sensitivity analysis method based on local partial derivatives is presented here to address these limitations. This new methodology informs AHP users of which pairwise comparisons most impact the derived …


A Miniaturized Spectrophotometric In Situ Ph Sensor For Seawater, Reuben C. Darlington Jan 2017

A Miniaturized Spectrophotometric In Situ Ph Sensor For Seawater, Reuben C. Darlington

Graduate Student Theses, Dissertations, & Professional Papers

Since the Industrial Revolution, the world's oceans have absorbed increasing amounts of CO2 and the resultant changes to the marine carbonate chemical system have reduced the pH by > 0.1 units (~ 30%) in surface waters. This acidification of the oceans has many far reaching impacts on marine life and there is great need of quality instrumentation to assess and follow the changing carbonate system. This MIS project aims to develop a low cost pH sensor with high precision and accuracy for open sea measurements with special emphasis on reduced size and cost. Design effort is based on the commercially available …


Human-Intelligence/Machine-Intelligence Decision Governance: An Analysis From Ontological Point Of View, Faisal Mahmud, Teddy Steven Cotter Jan 2017

Human-Intelligence/Machine-Intelligence Decision Governance: An Analysis From Ontological Point Of View, Faisal Mahmud, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

The increasing CPU power and memory capacity of computers, and now computing appliances, in the 21st century has allowed accelerated integration of artificial intelligence (AI) into organizational processes and everyday life. Artificial intelligence can now be found in a wide range of organizational processes including medical diagnosis, automated stock trading, integrated robotic production systems, telecommunications routing systems, and automobile fuzzy logic controllers. Self-driving automobiles are just the latest extension of AI. This thrust of AI into organizations and everyday life rests on the AI community’s unstated assumption that “…every aspect of human learning and intelligence could be so precisely described …


A Thermally Stabilized Fluorescent Organic Chromophore, Brendan P. Hughes Jan 2017

A Thermally Stabilized Fluorescent Organic Chromophore, Brendan P. Hughes

Graduate Dissertations and Theses

A fluorescent chromophore, hereby designated as cyanine dye, has been bound to generated zinc oxide nanoparticles. It has been shown that the material not only retains the characteristic absorption peak of the native chromophore, but it also continues to fluoresce with comparable intensity. The binding occurs through a Zn – O2C bridge, which allows for vibrational relaxation as the dye heats up, yet also preserves the optical properties of the dye. This bond linkage can be observed from the comparison of FT-IR spectra of the nanoparticles and the native dye, designated by a shift in one of the …


Representing And Inferring Mental Workload Via Defeasible Reasoning: A Comparison With The Nasa Task Load Index And The Workload Profile, Lucas Middeldorf Rizzo, Luca Longo Jan 2017

Representing And Inferring Mental Workload Via Defeasible Reasoning: A Comparison With The Nasa Task Load Index And The Workload Profile, Lucas Middeldorf Rizzo, Luca Longo

Conference papers

The NASA Task Load Index (NASA − TLX) and the Workload Profile (WP) are likely the most employed instruments for subjective mental workload (MWL) measurement. Numerous areas have made use of these methods for assessing human performance and thusly improving the design of systems and tasks. Unfortunately, MWL is still a vague concept, with different definitions and no universal measure. This research investigates the use of defeasible reasoning to represent and assess MWL. Reasoning is defeasible when a conclusion, supported by a set of premises, can be retracted in the light of new information. In this empirical study, this type …


On The Relationship Between Sampling Rate And Hidden Markov Models Accuracy In Non-Intrusive Load Monitoring, Steven Lynch, Luca Longo Jan 2017

On The Relationship Between Sampling Rate And Hidden Markov Models Accuracy In Non-Intrusive Load Monitoring, Steven Lynch, Luca Longo

Conference papers

Providing domestic energy consumers with a detailed breakdown of their electricity consumption, at the appliance level, empowers the consumer to better manage that consumption and reduce their over- all electricity demand. Non-Intrusive Load Monitoring (NILM) is one method of achieving this breakdown and makes use of one sensor which measures overall combined electricity usage. As all appliances are measured in combination in NILM this consumption must be disaggregated to extract appliance level consumption. Machine learning techniques can be adopted to perform this disaggregation with various levels of accuracy, with Hidden Markov Model (HMM) derivatives ordering among the most accurate results. …


Abusive Text Detection Using Neural Networks, Hao Chen, Susan Mckeever, Sarah Jane Delany Jan 2017

Abusive Text Detection Using Neural Networks, Hao Chen, Susan Mckeever, Sarah Jane Delany

Conference papers

eural network models have become increasingly popular for text classification in recent years. In particular, the emergence of word embeddings within deep learning architectures has recently attracted a high level of attention amongst researchers. In this paper, we focus on how neural network models have been applied in text classification. Secondly, we extend our previous work [4, 3] using a neural network strategy for the task of abusive text detection. We compare word embedding features to the traditional feature representations such as n-grams and handcrafted features. In addition, we use an off-the-shelf neural network classifier, FastText[16]. Based on our results, …


How Short Is A Piece Of String?: The Impact Of Text Length And Text Augmentation On Short-Text Classification Accuracy, Austin Mccartney, Svetlana Hensman, Luca Longo Jan 2017

How Short Is A Piece Of String?: The Impact Of Text Length And Text Augmentation On Short-Text Classification Accuracy, Austin Mccartney, Svetlana Hensman, Luca Longo

Conference papers

Recent increases in the use and availability of short messages have created opportunities to harvest vast amounts of information through machine-based classification. However, traditional classification methods have failed to yield accuracies comparable to classification accuracies on longer texts. Several approaches have previously been employed to extend traditional methods to overcome this problem, including the enhancement of the original texts through the construction of associations with external data supplementation sources. Existing literature does not precisely describe the impact of text length on classification performance. This work quantitatively examines the changes in accuracy of a small selection of classifiers using a variety …


A Comparison Of Automatic Search Query Enhancement Algorithms That Utilise Wikipedia As A Source Of A Priori Knowledge, Kyle Goslin, Markus Hofmann Jan 2017

A Comparison Of Automatic Search Query Enhancement Algorithms That Utilise Wikipedia As A Source Of A Priori Knowledge, Kyle Goslin, Markus Hofmann

Conference papers

This paper describes the benchmarking and analysis of five Automatic Search Query Enhancement (ASQE) algorithms that utilise Wikipedia as the sole source for a priori knowledge. The contributions of this paper include: 1) A comprehensive review into current ASQE algorithms that utilise Wikipedia as the sole source for a priori knowledge; 2) benchmarking of five existing ASQE algorithms using the TREC-9 Web Topics on the ClueWeb12 data set and 3) analysis of the results from the benchmarking process to identify the strengths and weaknesses each algorithm. During the benchmarking process, 2,500 relevance assessments were performed. Results of these tests are …


Influence Of Macular Pigment Optical Density Spatial Distribution On Intraocular Scatter, Christopher Putnam, Pauline Bland, Carl Bassi Jan 2017

Influence Of Macular Pigment Optical Density Spatial Distribution On Intraocular Scatter, Christopher Putnam, Pauline Bland, Carl Bassi

College of Optometry Faculty Works

No abstract provided.


A Climatological And Multiscale Analysis Of Cold Air Outbreaks In The Northeast United States, Zachary Baker Murphy Jan 2017

A Climatological And Multiscale Analysis Of Cold Air Outbreaks In The Northeast United States, Zachary Baker Murphy

Legacy Theses & Dissertations (2009 - 2024)

The results of a climatological and multiscale analysis of cold air outbreaks (CAOs) that impacted the Northeast U.S. during 1948–2015 are presented. This climatological and multiscale analysis was based on daily minimum temperature data extracted from the National Centers for Environmental Information (NCEI) Global Historical Climatology Network-Daily dataset for 53 stations that were distributed throughout nine climate regions defined by the NCEI. A CAO is diagnosed whenever two or more stations within an NCEI climate region experience three or more consecutive days where the daily minimum temperatures at a station fall below the 31-day centered moving average of the fifth …


An Introduction To Ricci Flow For Two-Dimensional Manifolds, Paul Bracken Jan 2017

An Introduction To Ricci Flow For Two-Dimensional Manifolds, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The study of diferentiable manifolds is a deep an extensive area of mathematics. A technique such as the study of the Ricci flow turns out to be a very useful tool in this regard. This flow is an evolution of a Riemannian metric driven by a parabolic type of partial differential equation. It has attracted great interest recently due to its important achievements in geometry such as Perelman's proof of the geometrization conjecture and Brendle-Schoen's proof of the differentiable sphere theorem. It is the purpose here to give a comprehensive introduction to the Ricci flow on manifolds of dimension two …


Search For Post-Merger Gravitational Waves From The Remnant Of The Binary Neutron Star Merger Gw170817, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier Jan 2017

Search For Post-Merger Gravitational Waves From The Remnant Of The Binary Neutron Star Merger Gw170817, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier

Physics and Astronomy Faculty Publications and Presentations

The first observation of a binary neutron star (NS) coalescence by the Advanced LIGO and Advanced Virgo gravitational-wave (GW) detectors offers an unprecedented opportunity to study matter under the most extreme conditions. After such a merger, a compact remnant is left over whose nature depends primarily on the masses of the inspiraling objects and on the equation of state of nuclear matter. This could be either a black hole (BH) or an NS, with the latter being either long-lived or too massive for stability implying delayed collapse to a BH. Here, we present a search for GWs from the remnant …


Determination And Analysis Of Dscovr-Eipc Satellite-Retrieved Radiance From Cloud Geometric And Optical Properties, Emily Christine Morgan Jan 2017

Determination And Analysis Of Dscovr-Eipc Satellite-Retrieved Radiance From Cloud Geometric And Optical Properties, Emily Christine Morgan

Legacy Theses & Dissertations (2009 - 2024)

Using simulations and numerical fitting, this work sought to describe the satellite-retrieved radiance of clouds as a function of their thermodynamic and optical properties. Subsequently, this understanding can then be used in a look-up-table to determine the properties of clouds imaged by the EPIC sensor in the NASA DSCOVR satellite. In this study, background oxygen absorption was modeled in a radiative transfer model and convolved with EPIC filter functions for two absorption-reference pairs for Oxygen A- and B-band. This absorption profile was established as the primary vertical coordinate in this study, leveraging the similarity principle to allow for intercomparison of …


Average Shortest Path Length In A Novel Small-World Network, Andrea J. Allen Jan 2017

Average Shortest Path Length In A Novel Small-World Network, Andrea J. Allen

Honors Papers

We study a novel model of random graph which exhibits the structural characteristics of the Watts- Strogatz small-world network. The small-world network is characterized by a high level of local clustering while also having a relatively small graph diameter. The same behavior that makes the Watts-Strogatz model behave like this also makes it difficult to analyze. Our model addresses this issue, closely mimicking the same structure experimentally while following a constructive process that makes it easier to analyze mathematically. We present a bound on the average shortest path length in our new model, which we approach by looking at the …


Digital Morphologies: Environmentally-Influenced Generative Forms, Sage Jenson Jan 2017

Digital Morphologies: Environmentally-Influenced Generative Forms, Sage Jenson

Honors Papers

We present a generative method to grow triangular meshes with organically-shaped features. Through the application of simplified forces, millions of particles develop into complex 3D forms in silico. These forms interact with external environments in a variety of ways, allowing for the integration of the proposed technique with pre-existing 3D objects and scenes. Large simulation sizes were computationally achieved through the massively parallel capabilities of modern Graphics Processing Units (GPUs).


Grace's Inheritance, James Noble, Andrew P. Black, Kim B. Bruce, Michael Homer, Timothy Jones Jan 2017

Grace's Inheritance, James Noble, Andrew P. Black, Kim B. Bruce, Michael Homer, Timothy Jones

Computer Science Faculty Publications and Presentations

This article is an apologia for the design of inheritance in the Grace educational programming language: it explains how the design of Grace’s inheritance draws from inheritance mechanisms in predecessor languages, and defends that design as the best of the available alternatives. For simplicity, Grace objects are generated from object constructors, like those of Emerald, Lua, and Javascript; for familiarity, the language also provides classes and inheritance, like Simula, Smalltalk and Java. The design question we address is whether or not object constructors can provide an inheritance semantics similar to classes.


Orthosymmetric Maps And Polynomial Valuations, Stephan Christopher Roberts Jan 2017

Orthosymmetric Maps And Polynomial Valuations, Stephan Christopher Roberts

Electronic Theses and Dissertations

We present a characterization of orthogonally additive polynomials on vector lattices as orthosymmetric multilinear maps. Our proof avoids partitionaly orthosymmetric maps and results that represent orthogonally additive polynomials as linear maps on a power. We also prove band characterizations for order bounded polynomial valuations and for order continuous polynomials of order bounded variation. Finally, we use polynomial valuations to prove that a certain restriction of the Arens extension of a bounded orthosymmetric multilinear map is orthosymmetric.


Towards The Synthesis Of A Polyamine Perylenebisimide Derivative For Intercalation Into Quadruplex Dna, Bobby May Jan 2017

Towards The Synthesis Of A Polyamine Perylenebisimide Derivative For Intercalation Into Quadruplex Dna, Bobby May

Honors Theses

Perylenebisimide intercalation in G-quadruplex DNA is an area of study that has increasing interest in cancer research. The ability of perylenebisimides to interrupt the structures of the G4 DNA on the end of telomeres has allowed for the observation of how the variable-regions of the perylenebisimide can have differing effects on anticancer properties. The purpose of this experiment was to synthesize a perylenebisimide with the intentions of observing its intercalating properties with G-quadruplex DNA. In order to accomplish this, dibenzylamine was substituted onto chloroacetonitrile through an SN2 reaction to produce 2-(dibenzylamino)acetonitrile. The 2-(dibenzylamino)acetonitrile was then reduced with LAH to yield …


Spectroscopic And Computational Studies Of The Hydrogen Bonding Interactions Of Hydroxyethyl Ethers, Ashley Elizabeth Williams Jan 2017

Spectroscopic And Computational Studies Of The Hydrogen Bonding Interactions Of Hydroxyethyl Ethers, Ashley Elizabeth Williams

Honors Theses

The isoenzymatic form of microsomal cytochrome P450, CYP2E1, is involved in the formation of oxygen free radicals, specifically hydroxyethyl ether. Chronic alcohol abuse has been found to induce larger levels of CYP2E1 in the liver, thus increasing production of these harmful free radicals. Generation of the hydroxyethyl ether oxygen free radicals occurs during the metabolism of ethanol in microsomes. The hydrogen-bonding interactions of hydroxyethyl ethers with water have yet to be analyzed, and information regarding the interactions with water can be applied directly to biological systems. Here, we employ Raman spectroscopy and computational chemistry to study hydroxyethyl ether complexes in …


Measurement Of The Verdet Constant For A Previously Uncharacterized Fused Quartz Glass, Samyukta Krishnamurthy Jan 2017

Measurement Of The Verdet Constant For A Previously Uncharacterized Fused Quartz Glass, Samyukta Krishnamurthy

Honors Theses

The objective of this experiment is to measure and analyze the Verdet constant for Corning 7980, a fused quartz glass with no previously published Verdet constant data. This quartz glass is being used at the Belle II experiment at Tsukuba, Japan. The Verdet constant is measured using the Faraday effect — a magneto-optical phenomenon that describes the rotation of the plane of polarization of light within a medium in the presence of an external magnetic field. This experiment quantifies the rotation of the plane of polarization with respect to the wavelength and the magnetic field. Data collected through this experiment …


Chemical Oxidation For Mitigation Of Uv-Quenching Substances (Uvqs) From Municipal Landfill Leachate: Fenton Process Versus Ozonation, Chanil Jung, Yang Deng, Renzun Zhao, Kevin Torrens Jan 2017

Chemical Oxidation For Mitigation Of Uv-Quenching Substances (Uvqs) From Municipal Landfill Leachate: Fenton Process Versus Ozonation, Chanil Jung, Yang Deng, Renzun Zhao, Kevin Torrens

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

UV-quenching substance (UVQS), as an emerging municipal solid waste (MSW)-derived leachate contaminant, has a potential to interfere with UV disinfection when leachate is disposed of at publicly owned treatment works (POTWs). The objective of this study was to evaluate and compare two chemical oxidation processes under different operational conditions, i.e. Fenton process and ozonation, for alleviation of UV254 absorbance of a biologically pre-treated landfill leachate. Results showed that leachate UV254 absorbance was reduced due to the UVQS decomposition by hydroxyl radicals (·OH) during Fenton treatment, or by ozone (O3) and ·OH during ozonation. Fenton process exhibited a better treatment performance …


The Role Of N-Terminal Acidic Inserts On The Dynamics Of The Tau Protein., Miranda Redmond Jan 2017

The Role Of N-Terminal Acidic Inserts On The Dynamics Of The Tau Protein., Miranda Redmond

Graduate College Dissertations and Theses

Alzheimer’s disease (AD), the most prevalent neurodegenerative disease, is characterized in part by disruptions in axonal transport. Axonal transport is a process by which motor proteins carry organelles and other cargo made in the neuronal cell body along microtubule tracks to distal regions of the axon. The microtubule-associated protein (MAP) Tau plays a crucial role in regulating axonal transport, and is implicated in the development of AD and other types of dementia collectively known as Tauopathies. Tau is a neuronal-specific MAP that has six isoforms alternatively spliced from a single gene. These isoforms differ by the presence of zero, one, …


New Approaches To Heterocycle Synthesis: A Greener Route To Structurally Complex Protonated Azomethine Imines, And Their Use In 1,3-Dipolar Cycloadditions, Ram Chandra Dhakal Jan 2017

New Approaches To Heterocycle Synthesis: A Greener Route To Structurally Complex Protonated Azomethine Imines, And Their Use In 1,3-Dipolar Cycloadditions, Ram Chandra Dhakal

Graduate College Dissertations and Theses

1-Aza-2-azoniaallene salts are reactive intermediates that undergo [3+2] cycloaddition with many different types of multiple bonds. For the past several years, the Brewer group has studied the reactivity of these intermediates in intramolecular reactions, and have discovered that these cationic heteroallenes can react through a variety of other, mechanistically distinct, pathways to give different classes of nitrogen heterocycles. For example, prior work in the Brewer group revealed that 1-aza-2-azoniaallene salts could react in an intramolecular [4+2] cycloaddition reaction to give protonated azomethine imine salts containing a 1,2,3,4-tetrahydrocinnoline scaffold. Further study of the scope and limitations of this Diels-Alder-like reaction are …


Generation Of Electron Deficient Carbodiimides And Their Application In The Guanidine Forming, Zwitterionic 1,3-Diaza-Claisen Rearrangement, Joel Walker Jan 2017

Generation Of Electron Deficient Carbodiimides And Their Application In The Guanidine Forming, Zwitterionic 1,3-Diaza-Claisen Rearrangement, Joel Walker

Graduate College Dissertations and Theses

The 1,3-diaza Claisen rearrangement was initially discovered by the Madalengoitia group in the early 2000s. Tertiary, allylic, amines nucleophilically add to the carbon of a heterocumulene (isocyanate, isothiocyanate, or carbodiimide) to generate a zwitterion which then undergoes [3,3]-sigmatropic rearrangement. The rearrangements conducted with a carbodiimide generate guanidine-containing skeletons. The guanidine functional group is found in many biologically active products, making it a worthwhile chemical target.

To this end, strained, tertiary, allylic, amine 2-benzyl-2-azabicyclo[2.2.1]hept-5-ene reacts with in-situ generated carbodiimides in the 1,3-diaza-Claisen rearrangement to afford structurally interesting bicyclic guanidines. Use of more electron deficient carbodiimides makes these rearrangements more facile; however, …


Cyclopentadienyl Compounds Of The First Row Transition Metals And Early Actinides: Novel Main-Group Bond Forming Catalysis And New Metallacycles, Justin Kane Pagano Jan 2017

Cyclopentadienyl Compounds Of The First Row Transition Metals And Early Actinides: Novel Main-Group Bond Forming Catalysis And New Metallacycles, Justin Kane Pagano

Graduate College Dissertations and Theses

Cyclopentadienyl first row transition-metal compounds have been well studied since the 1950's, with the nearly ubiquitous CpFe(CO)2Me (FpMe) (Cp = η5-C5H5) being one of the first organometallics to be fully characterized. Despite the decades of study that have been poured into this complex, reactions between FpMe and primary phosphines have not been reported. Catalytic reactions with primary phosphines are generally understudied, including dehydrocoupling and P-C bond forming reactions such as hydrophosphination. A novel mechanism of dehydrocoupling and P-C bond formation that has received even more limited attention is α-elimination. This dissertation describes efforts in proving that FpMe is a competent …


Fingerprinting Wolframite: An Atomic/Crystallographic, Chemical And Spectroscopic Study Along The Solid Solution Series, Gina Marie Accorsi Jan 2017

Fingerprinting Wolframite: An Atomic/Crystallographic, Chemical And Spectroscopic Study Along The Solid Solution Series, Gina Marie Accorsi

Graduate College Dissertations and Theses

In accordance with the 2010 Dodd-Frank Act, conflict minerals refer to gold, tantalum, tin, and tungsten bearing minerals sourced from the Democratic Republic of Congo (DRC) that have been mined illegally and used to funnel funds to rebel forces. In response to an increasing demand for these metals used in cellphones, computers, and other popular technologies, Dodd-Frank mandates that industrial consumers demonstrate due diligence and assure that the materials they use have been extracted legally. Because current chain-of-custody methods have not been effective in sourcing ores, a study was undertaken whereby the range of mineralogical characteristics of 15 samples along …


An Exposition Of Selberg's Sieve, Jack Dalton Jan 2017

An Exposition Of Selberg's Sieve, Jack Dalton

Graduate College Dissertations and Theses

A number of exciting recent developments in the field of sieve theory have been done concerning bounded gaps between prime numbers. One of the main techniques used in these papers is a modified version of Selberg's Sieve from the 1940's. While there are a number of sources that explain the original sieve, most, if not all, are quite inaccessible to those without significant experience in analytic number theory. The goal of this exposition is to change that. The statement and proof of the general form of Selberg's sieve is, by itself, difficult to understand and appreciate. For this reason, the …


Detecting Landscape Response To Perturbations By Climate And Base Level In Central Pennsylvania Using In-Situ 10be And 26al, Alison R. Denn Jan 2017

Detecting Landscape Response To Perturbations By Climate And Base Level In Central Pennsylvania Using In-Situ 10be And 26al, Alison R. Denn

Graduate College Dissertations and Theses

The change of topography with time and the consequent structure of Earth's surface is dependent on the production and transport of weathered bedrock. I use measurements of in-situ cosmogenic 10Be to investigate erosion rates and exposure ages of boulders, streams, and hillslope sediments in central Pennsylvania, a landscape shaped by glacial/interglacial climate cycles and changes in base level. I measure rates of landscape change at three separate sites, Hickory Run boulder field, Young Womans Creek watershed, and Garner Run, a small upland catchment bounded by two ridgelines.

Hickory Run Boulder field is the largest of its kind in the eastern …