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Articles 991 - 1020 of 2906

Full-Text Articles in Physical Sciences and Mathematics

The Steiner Problem On Closed Surfaces Of Constant Curvature, Andrew Logan Mar 2015

The Steiner Problem On Closed Surfaces Of Constant Curvature, Andrew Logan

Theses and Dissertations

The n-point Steiner problem in the Euclidean plane is to find a least length path network connecting n points. In this thesis we will demonstrate how to find a least length path network T connecting n points on a closed 2-dimensional Riemannian surface of constant curvature by determining a region in the covering space that is guaranteed to contain T. We will then provide an algorithm for solving the n-point Steiner problem on such a surface.


Re-Calibration Of The Periods Of Selected Cepheids From The Hubble Space Telescope Key Project Using Time Correction, Muxue Liu Mar 2015

Re-Calibration Of The Periods Of Selected Cepheids From The Hubble Space Telescope Key Project Using Time Correction, Muxue Liu

Theses and Dissertations

The Hubble Space Telescope (HST) was originally proposed and funded in the 1970's with a launch planned for the early 1980's. However, the launch finally occurred on April 24, 1990, largely due to the Challenger accident. Once launched in 1990, one of HST's earliest projects was the Key Project. One of the main purposes of the Key Project was to calibrate the distances to nearby galaxies and determine a definitive value of the Hubble constant H0. All secondary distance determination methods were based on the period-luminosity relation of Cepheid variable stars. This thesis examines the Cepheid data from the Key …


Validity Of Holocene Analogs For Ancient Carbonate Stratigraphic Successions: Insights From A Heterogeneous Pleistocene Carbonate Platform Deposit, Colby Hazard Feb 2015

Validity Of Holocene Analogs For Ancient Carbonate Stratigraphic Successions: Insights From A Heterogeneous Pleistocene Carbonate Platform Deposit, Colby Hazard

Theses and Dissertations

Observations of modern carbonate depositional environments and their accompanying depositional models have been used for decades in the reconstruction and interpretation of ancient carbonate depositional environments and stratigraphic successions. While these Holocene models are necessary for interpreting their more ancient counterparts, they inherently exclude important factors related to the erosion, diagenesis, and ultimate preservation of sediments and sedimentary structures that are ubiquitous in shallow marine carbonate environments. Andros Island, Bahamas is an ideal location to examine the validity of Holocene conceptual models, where geologically young (Late Pleistocene) limestones can be studied immediately adjacent to their well-documented modern equivalents. For this …


Organocatalytic Aryl−Aryl Bond Formation: An Atroposelective [3,3]‑Rearrangement Approach To Binam Derivatives, Gong-Qiang Li, Hongyin Gao, Craig Keene, Michael Devonas, Daniel H. Ess, LaśZlóKüRti * Jan 2015

Organocatalytic Aryl−Aryl Bond Formation: An Atroposelective [3,3]‑Rearrangement Approach To Binam Derivatives, Gong-Qiang Li, Hongyin Gao, Craig Keene, Michael Devonas, Daniel H. Ess, LaśZlóKüRti *

Journal of Undergraduate Research

Herein we disclose an organocatalytic aryl− aryl bond-forming process for the regio- and atropo- selective synthesis of 2,2′-diamino-1,1′-binaphthalenes (BINAMs). In the presence of catalytic amounts of axially chiral phosphoric acids, achiral N,N′-binaphthyl hydrazines undergo a facile [3,3]-sigmatropic rearrangement to afford enantiomerically enriched BINAM derivatives in good to excellent yield. This transformation represents the first

example of a metal-free, catalytic C(sp2)−C(sp2) bond

formation between two aromatic rings with concomitant de novo atroposelective installation of an axis of chirality. Density functional calculations reveal that, in the transition state for C−C bond formation, the phosphoric acid proton of …


Frontier: A Framework For Extracting And Organizing Biographical Facts In Historical Documents, Joseph Park Jan 2015

Frontier: A Framework For Extracting And Organizing Biographical Facts In Historical Documents, Joseph Park

Theses and Dissertations

The tasks of entity recognition through ontological commitment, fact extraction and organization with respect to a target schema, and entity deduplication have all been examined in recent years, and systems exist that can perform each individual task. A framework combining all these tasks, however, is still needed to accomplish the goal of automatically extracting and organizing biographical facts about persons found in historical documents into disambiguated entity records. We introduce FROntIER (Fact Recognizer for Ontologies with Inference and Entity Resolution) as the framework to recognize and extract facts using an ontology and organize facts of interest through inferring implicit facts …


Using Higher Ionization States To Increase Coulomb Coupling In An Ultracold Neutral Plasma, M. Lyon, Scott D. Bergeson, A. Diaw, M. S. Murillo Jan 2015

Using Higher Ionization States To Increase Coulomb Coupling In An Ultracold Neutral Plasma, M. Lyon, Scott D. Bergeson, A. Diaw, M. S. Murillo

Faculty Publications

We report measurements and simulations of the time-evolving rms velocity distribution in an ultracold neutral plasma. A strongly coupled ultracold neutral Ca+ plasma is generated by photoionizing laser-cooled atoms close to threshold. A fraction of these ions is then promoted to the second ionization state to form a mixed Ca+-Ca2+ plasma. By varying the time delay between the first and the second ionization events, a minimum in ion heating is achieved. We show that the Coulomb strong-coupling parameter Γ increases by a factor of 1.4 to a maximum value of 3.6. A pure Ca2+ plasma …


Instrument For Precision Long-Term Ss-Decay Rate Measurements, M. J. Ware, Scott D. Bergeson, J. E. Ellsworth, M. Groesbeck, J. E. Hansen, D. Pace, J. Peatross Jan 2015

Instrument For Precision Long-Term Ss-Decay Rate Measurements, M. J. Ware, Scott D. Bergeson, J. E. Ellsworth, M. Groesbeck, J. E. Hansen, D. Pace, J. Peatross

Faculty Publications

We describe an experimental setup for making precision measurements of relative ß-decay rates of 22Na, 36Cl, 54Mn, 60Co, 90Sr, 133Ba, 137Cs, 152Eu, and 154Eu. The radioactive samples are mounted in two automated sample changers that sequentially position the samples with high spatial precision in front of sets of detectors. The set of detectors for one sample changer consists of four Geiger-Müller (GM) tubes and the other set of detectors consists of two NaI scintillators. The statistical uncertainty in the count rate is few times 0.01% per day for the GM …


Strongly-Coupled Plasmas Formed From Laser-Heated Solids, M. Lyon, Scott D. Bergeson, G. Hart, M. S. Murillo Jan 2015

Strongly-Coupled Plasmas Formed From Laser-Heated Solids, M. Lyon, Scott D. Bergeson, G. Hart, M. S. Murillo

Faculty Publications

We present an analysis of ion temperatures in laser-produced plasmas formed from solids with different initial lattice structures. We show that the equilibrium ion temperature is limited by a mismatch between the initial crystallographic configuration and the close-packed configuration of a strongly-coupled plasma, similar to experiments in ultracold neutral plasmas. We propose experiments to demonstrate and exploit this crystallographic heating in order to produce a strongly coupled plasma with a coupling parameter of several hundred.


Fluorescence Imaging Of Analyte Profiles In An Inductively Coupled Plasma With Laser Ablation As A Sample Introduction Source, Lance Moses Jan 2015

Fluorescence Imaging Of Analyte Profiles In An Inductively Coupled Plasma With Laser Ablation As A Sample Introduction Source, Lance Moses

Theses and Dissertations

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has risen to among the top tier techniques for the direct analysis of solid samples. However, significant problems remain that must be solved to achieve the full analytical potential of LA-ICP-MS. Inefficient conversion of aerosol to ions within the ICP or transmission through the MS interface may decrease precision, sensitivity, and/or accuracy. Although fundamental mechanisms that govern ion production and transmission have been studied extensively in solution-nebulization (SN) ICP-MS instruments, significant gaps in our understanding remain. Furthermore, it is unclear to what extent differences between the aerosols generated during SN and LA …


Algebraic Semi-Classical Model For Reaction Dynamics, Tim Glenn Wendler Dec 2014

Algebraic Semi-Classical Model For Reaction Dynamics, Tim Glenn Wendler

Theses and Dissertations

We use an algebraic method to model the molecular collision dynamics of a collinear triatomic system. Beginning with a forced oscillator, we develop a mathematical framework upon which inelastic and reactive collisions are modeled. The model is considered algebraic because it takes advantage of the properties of a Lie algebra in the derivation of a time-evolution operator. The time-evolution operator is shown to generate both phase-space and quantum dynamics of a forced oscillator simultaneously. The model is considered semi-classical because only the molecule's internal degrees-of-freedom are quantized. The relative translation between the colliding atom and molecule in an exchange reaction …


The Bioluminescence Heterozygous Genome Assembler, Jared Calvin Price Dec 2014

The Bioluminescence Heterozygous Genome Assembler, Jared Calvin Price

Theses and Dissertations

High-throughput DNA sequencing technologies are currently revolutionizing the fields of biology and medicine by elucidating the structure and function of the components of life. Modern DNA sequencing machines typically produce relatively short reads of DNA which are then assembled by software in an attempt to produce a representation of the entire genome. Due to the complex structure of all but the smallest genomes, especially the abundant presence of exact or almost exact repeats, all genome assemblers introduce errors into the final sequence and output a relatively large set of contigs instead of full-length chromosomes (a contig is a DNA sequence …


Chaperone-Mediated Folding And Assembly Of Β-Propeller Proteins Into Cellular Signaling Complexes, Rebecca L. Plimpton Dec 2014

Chaperone-Mediated Folding And Assembly Of Β-Propeller Proteins Into Cellular Signaling Complexes, Rebecca L. Plimpton

Theses and Dissertations

G protein signaling depends on the ability of the individual subunits of the G protein heterotrimer to assemble into a functional complex. Formation of the G protein βγ (Gβγ) dimer is particularly challenging because it is an obligate dimer in which the individual subunits are unstable on their own. Recent studies have revealed an intricate chaperone system that brings the Gβ and Gγ subunits together. This system includes the cytosolic chaperonin containing TCP-1 (CCT) and a co-chaperone phosducin-like protein 1 (PhLP1). Two key intermediates in the Gβγ assembly process, the Gβ-CCT and the PhLP1-Gβ-CCT complexes, were isolated and their structures …


The 1852 Banda Arc Mega-Thrust Earthquake And Tsunami In Indonesia, Tsz Man Fisher Dec 2014

The 1852 Banda Arc Mega-Thrust Earthquake And Tsunami In Indonesia, Tsz Man Fisher

Theses and Dissertations

In 1852, a five-minute long earthquake hit the Banda Arc region that was felt over most of Indonesia. It caused uplift of new islands and sent a tsunami across the Banda Sea that reached a height of 8 meters at Banda Neira and was also registered at Ambon, Saparua and other islands. Records of the 1852 earthquake at multiple locations provide the constraints needed to reconstruct the disastrous event through earthquake intensity analysis and numerical modeling of the tsunami. Using tsunami heights and arrival times as the major constraints, best fit numerical models of the tsunami were constructed using Clawpack. …


Fabrication, Characterization, Optimization And Application Development Of Novel Thin-Layer Chromatography Plates, Supriya Singh Kanyal Dec 2014

Fabrication, Characterization, Optimization And Application Development Of Novel Thin-Layer Chromatography Plates, Supriya Singh Kanyal

Theses and Dissertations

This dissertation describes advances in the microfabrication of thin layer chromatography (TLC) plates. These plates are prepared by the patterning of carbon nanotube (CNT) forests on substrates, followed by their infiltration with an inorganic material. This document is divided into ten sections or chapters. Chapter 1 reviews the basics of conventional TLC technology. This technology has not changed substantially in decades. This chapter also mentions some of the downsides of the conventional approach, which include unwanted interactions of the binder in the plates with the analytes, relatively slow development times, and only moderately high efficiencies. Chapter 2 focuses primarily on …


The Existence Of A Discontinuous Homomorphism Requires A Strong Axiom Of Choice, Michael Steven Andersen Dec 2014

The Existence Of A Discontinuous Homomorphism Requires A Strong Axiom Of Choice, Michael Steven Andersen

Theses and Dissertations

Conner and Spencer used ultrafilters to construct homomorphisms between fundamental groups that could not be induced by continuous functions between the underlying spaces. We use methods from Shelah and Pawlikowski to prove that Conner and Spencer could not have constructed these homomorphisms with a weak version of the Axiom of Choice. This led us to define and examine a class of pathological objects that cannot be constructed without a strong version of the Axiom of Choice, which we call the class of inscrutable objects. Objects that do not need a strong version of the Axiom of Choice are scrutable. We …


Pro-Covering Fibrations Of The Hawaiian Earring, Nickolas Brenten Callor Dec 2014

Pro-Covering Fibrations Of The Hawaiian Earring, Nickolas Brenten Callor

Theses and Dissertations

Let H be the Hawaiian Earring, and let H denote its fundamental group. Assume (Bi) is an inverse system of bouquets of circles whose inverse limit is H. We give an explicit bijection between finite normal covering spaces of H and finite normal covering spaces of Bi. This bijection induces a correspondence between a certain family of inverse sequences of these covering spaces. The correspondence preserves the inverse limit of these sequences, thus offering two methods of constructing the same limit. Finally, we characterize all spaces that can be obtained in this fashion as a particular type of fibrations of …


Classifying And Cataloging Cyber-Security Incidents Within Cyber-Physical Systems, William B. Miller Dec 2014

Classifying And Cataloging Cyber-Security Incidents Within Cyber-Physical Systems, William B. Miller

Theses and Dissertations

In the past, there were perceived delineations between the cyber world and the physical world. We are becoming increasingly aware of the overlap between these two worlds, and the overlap itself is increasing. The overlap between these two worlds is known as cyber-physical systems. There have been several incidents involving cyber-physical systems and the number of these incidents is increasing dramatically. In the past there has been no effort to identify methods for describing these incidents in the unique context of cyber-physical systems. This research provides a taxonomy for classifying these incidents that focuses on cross domain, impact oriented analysis. …


Teachers' Curricular Reasoning And Mkt In The Context Of Algebra And Statistics, Kolby J. Gadd Dec 2014

Teachers' Curricular Reasoning And Mkt In The Context Of Algebra And Statistics, Kolby J. Gadd

Theses and Dissertations

This study investigates 7th grade teachers' curricular reasoning and MKT in algebra and statistics. Although the use of curriculum materials and MKT both influence the quality of mathematics instruction, no relationship between teachers' curricular reasoning and MKT was found. Further, teachers' curricular reasoning across algebra and statistics was very similar despite differences in these fields and differences in MKT. A model for thinking about the knowledge needed to provide high quality instruction is proposed by considering the role of curricular reasoning and MKT in instruction.


Normal Fault Block Or Giant Landslide? Baldy Block, Wasatch Range, Utah, Eric R. Meyer Dec 2014

Normal Fault Block Or Giant Landslide? Baldy Block, Wasatch Range, Utah, Eric R. Meyer

Theses and Dissertations

Understanding the interplay between surficial and tectonic processes in the development of Utah's Wasatch Range is vital to evaluating geologic hazards along the Wasatch Front. Baldy is a large (6.125 km3) block of limestone and sandstone structurally overlying shale on the western flank of Mount Timpanogos. It has been mapped as a downdropped normal fault block of Permian units, but no other trace of such a fault exists along the range. The Baldy block structurally overlies the weak Manning Canyon shale, which has produced a regional geomorphology replete with faceted spurs, landslide scarps and deposits. Structural, bio- and litho-stratigrahic mapping …


Compositional Analysis Of Three Clay Artifact Collections From The Southwestern United States, Kathleen R. Kirkham Dec 2014

Compositional Analysis Of Three Clay Artifact Collections From The Southwestern United States, Kathleen R. Kirkham

Theses and Dissertations

This study assessed ways compositional analysis, facilitated by portable X-ray fluorescence technology (PXRF), can be applied in the museum setting to resolve provenance issues and other collections management questions. A major segment of the study evaluated PXRF as a non-invasive geochemical analysis technique to address concerns about whether the resolution of results is sufficient to draw meaningful conclusions. Compositional analysis, mainly facilitated by PXRF, was successfully applied to three clay artifact collections from the southwestern United States. Pottery sherds from Fourmile Ruin were analyzed using PXRF and compared to analyses from invasive wavelength-dispersive XRF and X-ray diffraction techniques. Expanding the …


Synthesis And Characterization Of Complex Molecular Assemblies On Surfaces, Nitesh Madaan Dec 2014

Synthesis And Characterization Of Complex Molecular Assemblies On Surfaces, Nitesh Madaan

Theses and Dissertations

The research presented in this dissertation is focused on the construction of complex molecular structures on planar gold and silicon dioxide surfaces using a variety of surface modification techniques, along with thorough surface characterization at each modification step. The dissertation is structured into six separate chapters. In Chapter 1, an introduction to the importance and implications of molecular level surface modification, commonly employed surface modification methods, and available surface characterization techniques is presented. Chapter 2 shows applications of novel methodologies for the functionalization of gold surfaces using alkane dithiol self-assembled monolayers and thiol-ene click chemistry. The resulting functionalized gold substrates …


Replication And Knowledge Production In Empirical Software Engineering Research, Jonathan L. Krein Dec 2014

Replication And Knowledge Production In Empirical Software Engineering Research, Jonathan L. Krein

Theses and Dissertations

Although replication is considered an indispensable part of the scientific method in software engineering, few replication studies are published each year. The rate of replication, however, is not surprising given that replication theory in software engineering is immature. Not only are replication taxonomies varied and difficult to reconcile, but opinions on the role of replication contradict. In general, we have no clear sense of how to build knowledge via replication, particularly given the practical realities of our research field. Consequently, most replications in software engineering yield little useful information. In particular, the vast majority of external replications (i.e., replications performed …


Microchip Thermal Gradient Gas Chromatography, Anzi Wang Dec 2014

Microchip Thermal Gradient Gas Chromatography, Anzi Wang

Theses and Dissertations

Although the airbath oven is a reliable heating method for gas chromatography (GC), resistive heating is needed for higher analytical throughput and on-site chemical analysis because of size, heating rate and power requirements. In the last thirty years, a variety of resistive heating methods were developed and implemented for both benchtop and portable GC systems. Although fast heating rates and low power consumption have been achieved, losses in column efficiency and resolution, complex construction processes and difficulties experienced in recovering damaged columns have also become problematic for routine use of resistively heated columns. To solve these problems, a new resistively …


Framework To Implement Authentication, Authorization And Secure Communications In A Multiuser Collaborative Cax Environment, Francis Mensah Dec 2014

Framework To Implement Authentication, Authorization And Secure Communications In A Multiuser Collaborative Cax Environment, Francis Mensah

Theses and Dissertations

Computer Aided Design (CAD) applications have historically been based on a single user per application architecture. Although this architecture is still popular to date, it does have several drawbacks. First of all the single user CAD architecture inhibits a concurrent engineering design process where several designers can work on the same model simultaneously. This limitation introduces time inefficiency especially when a project involves geographically dispersed designers. A solution to these drawbacks could be a transition from the traditional single user CAD architecture to a multiuser collaborative architecture. Advances in computer networking technologies, especially relating to the Internet, have provided the …


A Covering System With Minimum Modulus 42, Tyler Owens Dec 2014

A Covering System With Minimum Modulus 42, Tyler Owens

Theses and Dissertations

We construct a covering system whose minimum modulus is 42. This improves the previous record of 40 by P. Nielsen.


The Nature And Origin Of Pebble Dikes And Associated Alteration: Tintic Mining District (Ag-Pb-Zn), Utah, Douglas M. Johnson Nov 2014

The Nature And Origin Of Pebble Dikes And Associated Alteration: Tintic Mining District (Ag-Pb-Zn), Utah, Douglas M. Johnson

Theses and Dissertations

In many ore deposits throughout the world, brecciation often accompanies or occurs in association with mineralization (Sillitoe, 1985). Such is the case in the Tintic Mining District (Ag-Pb-Zn) of north-central Utah, where unique breccia features called pebble dikes occur alongside significant mineralization. Pebble dikes are tabular bodies of breccia, which consist of angular to rounded clasts of quartzite, shale, carbonate, and minor igneous rock cemented in a fine-grained clastic matrix. All clasts now lie above or adjacent to corresponding source rocks. Dikes are thin, typically less than 0.3 m wide to as much as 1 m, and can exceed 100 …


A Privacy Risk Scoring Framework For Mobile, Jedidiah Spencer Montgomery Nov 2014

A Privacy Risk Scoring Framework For Mobile, Jedidiah Spencer Montgomery

Theses and Dissertations

Protecting personal privacy has become an increasingly important issue as computers become a more integral part of everyday life. As people begin to trust more personal information to be contained in computers they will question if that information is safe from unwanted intrusion and access. With the rise of mobile devices (e.g., smartphones, tablets, wearable technology) users have enjoyed the convenience and availability of stored personal information in mobile devices, both in the operating system and within applications.For a mobile application to function correctly it needs permission or privileges to access and control various resources and controls on the mobile …


Scalable Detection And Extraction Of Data In Lists In Ocred Text For Ontology Population Using Semi-Supervised And Unsupervised Active Wrapper Induction, Thomas L. Packer Oct 2014

Scalable Detection And Extraction Of Data In Lists In Ocred Text For Ontology Population Using Semi-Supervised And Unsupervised Active Wrapper Induction, Thomas L. Packer

Theses and Dissertations

Lists of records in machine-printed documents contain much useful information. As one example, the thousands of family history books scanned, OCRed, and placed on-line by FamilySearch.org probably contain hundreds of millions of fact assertions about people, places, family relationships, and life events. Data like this cannot be fully utilized until a person or process locates the data in the document text, extracts it, and structures it with respect to an ontology or database schema. Yet, in the family history industry and other industries, data in lists goes largely unused because no known approach adequately addresses all of the costs, challenges, …


Ion Structure And Energetics In The Gas Phase Characterized Using Fourier Transfom Ion Cyclotron Resonance Mass Spectrometry, Chad A. Jones Sep 2014

Ion Structure And Energetics In The Gas Phase Characterized Using Fourier Transfom Ion Cyclotron Resonance Mass Spectrometry, Chad A. Jones

Theses and Dissertations

In this dissertation, I use Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) to study the structure and energetics of gas phase ions. Infrared multiphoton dissociation spectroscopy (IRMPD) is a technique for measuring the IR spectrum of gas phase ions in a Penning trap. I use this technique to investigate the conformation of cucurbituril complexes, terminal diamines, and protonated amino acids. Cross sectional areas by Fourier transform ion cyclotron resonance mass spectrometry (CRAFTI) is a technique developed by the Dearden lab to measure the cross section of gas phase ions. In this work, I further develop a fundamental understanding of …


Intelligent Indexing: A Semi-Automated, Trainable System For Field Labeling, Robert T. Clawson Sep 2014

Intelligent Indexing: A Semi-Automated, Trainable System For Field Labeling, Robert T. Clawson

Theses and Dissertations

We present Intelligent Indexing: a general, scalable, collaborative approach to indexing and transcription of non-machine-readable documents that exploits visual consensus and group labeling while harnessing human recognition and domain expertise. In our system, indexers work directly on the page, and with minimal context switching can navigate the page, enter labels, and interact with the recognition engine. Interaction with the recognition engine occurs through preview windows that allow the indexer to quickly verify and correct recommendations. This interaction is far superior to conventional, tedious, inefficient post-correction and editing. Intelligent Indexing is a trainable system that improves over time and can provide …