Physical Sciences and Mathematics Commons^™

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 …

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.

Radio Emission Toward Regions Of Massive Star Formation In The Large Magellanic Cloud, Adam Johanson

Theses and Dissertations

Four regions of massive star formation in the Large Magellanic Cloud (LMC) were observed for water and methanol maser emission and radio continuum emission. A total of 42 radio detections were made including 27 new radio sources, four water masers, and eight compact HII regions. The lobes of a radio galaxy were resolved for the first time, and the host galaxy identified. Seven sources were associated with known massive young stellar objects (YSOs). A multi-wavelength analysis using both the infrared and radio spectrum was used to characterize the sources. Mid-infrared color-magnitude selection criteria for ultracompact HII (UCHII) regions in the …

A Mathematical Model Of Amoeboid Cell Motion As A Continuous-Time Markov Process, Lynnae Despain

Theses and Dissertations

Understanding cell motion facilitates the understanding of many biological processes such as wound healing and cancer growth. Constructing mathematical models that replicate amoeboid cell motion can help us understand and make predictions about real-world cell movement. We review a force-based model of cell motion that considers a cell as a nucleus and several adhesion sites connected to the nucleus by springs. In this model, the cell moves as the adhesion sites attach to and detach from a substrate. This model is then reformulated as a random process that tracks the attachment characteristic (attached or detached) of each adhesion site, the …

Optimization Of Nonadsorptive Polymerized Polyethylene Glycol Diacrylate As A Material For Microfluidics And Sensor Integration, Chad Rogers

Theses and Dissertations

Microfluidics is a continually growing field covering a wide range of applications, such as cellular analysis, biomarker quantification, and drug discovery; but in spite of this, the field of microfluidics remains predominately academic. New materials are pivotal in providing tailored properties to improve device integration and decrease prototype turnaround times. In biosensing, nonspecific adsorption in microfluidic systems can deplete target molecules in solution and prevent analytes, especially those at low concentrations, from reaching the detector. Polyethylene glycol diacrylate (PEGDA) mixed with photoinitiator forms, on exposure to ultraviolet (UV) radiation, a polymer with inherent resistance to nonspecific adsorption. Optimization of the …

Simulations Of Electron Trajectories In An Intense Laser Focus For Photon Scattering Experiments, Grayson J. Tarbox

Theses and Dissertations

An experiment currently underway at BYU is designed to test whether the size of a free electron wave packet affects the character of scattered radiation. Using a semi-classical argument wherein the wave packet is treated as a diffuse charge distribution, one would expect strong suppression of radiation in the direction perpendicular to the propagating field as the wave packet grows in size to be comparable to the wavelength of the driving field. If one disallows the interaction of the wave packet with itself, as is the case when calculating the rate of emission using QED, then regardless of size, the …

Judicious Use Of Communication For Inherently Parallel Optimization, Andrew W. Mcnabb

Theses and Dissertations

Function optimization---finding the minimum or maximum of a given function---is an extremely challenging problem with applications in physics, economics, machine learning, engineering, and many other fields. While optimization is an active area of research, only a portion of this work acknowledges parallel computation, which is now widely available. Today, anyone with a modest budget can buy a cluster with hundreds of cores, pay for access to a supercomputer with thousands of processors, or at least purchase a laptop with 8 cores. Thus, an algorithm that works well in serial but cannot be parallelized is needlessly inefficient in real-life computationalenvironments.We address …

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 *

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 …

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.

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 …

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 …

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

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 …

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.

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 …

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 …

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

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

Theses and Dissertations

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

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 …

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 …

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 …

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 …

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 …

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 …

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. …

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 …

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 …

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. …