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Articles 901 - 930 of 2906

Full-Text Articles in Physical Sciences and Mathematics

Fast Inference For Interactive Models Of Text, Jeffrey A. Lund Sep 2015

Fast Inference For Interactive Models Of Text, Jeffrey A. Lund

Theses and Dissertations

Probabilistic models of text are a useful tool for enabling the analysis of large collections of digital text. For example, Latent Dirichlet Allocation can quickly produce topical summaries of large collections of text documents. Many important uses cases of such models include human interaction during the inference process for these models of text. For example, the Interactive Topic Model extends Latent Dirichlet Allocation to incorporate human expertiese during inference in order to produce topics which are better suited to individual user needs. However, interactive use cases of probabalistic models of text introduce new constraints on inference - the inference procedure …


Improving Production Of Carbon Nanotube Composites, Dan Broadbent Aug 2015

Improving Production Of Carbon Nanotube Composites, Dan Broadbent

Faculty Publications

Carbon nanotube (CNT) composites offer great promise for making lighter, thinner and stronger structures. Producing CNT composites, however, can be tricky. The focus of this work is to improve production yields of CNT composites by doing research and development in two areas:

  • Research the relationship between ethylene gas concentrations used during CNT growth and yields of usable composite films produced.
  • Develop furnace for growing larger CNT samples, which will enable larger sizes and quantities of research product.


A Nonabelian Landau-Ginzburg B-Model Construction, Ryan Thor Sandberg Aug 2015

A Nonabelian Landau-Ginzburg B-Model Construction, Ryan Thor Sandberg

Theses and Dissertations

The Landau-Ginzburg (LG) B-Model is a significant feature of singularity theory and mirror symmetry. Krawitz in 2010, guided by work of Kaufmann, provided an explicit construction for the LG B-model when using diagonal symmetries of a quasihomogeneous, nondegenerate polynomial. In this thesis we discuss aspects of how to generalize the LG B-model construction to allow for nondiagonal symmetries of a polynomial, and hence nonabelian symmetry groups. The construction is generalized to the level of graded vector space and the multiplication developed up to an unknown factor. We present complete examples of nonabelian LG B-models for the polynomials x^2y + y^3, …


Peroxy Radical - Water Complexes: Their Role In The Atmosphere, Sambhav Rajendra Kumbhani Aug 2015

Peroxy Radical - Water Complexes: Their Role In The Atmosphere, Sambhav Rajendra Kumbhani

Theses and Dissertations

The importance of radical-water complexes in the atmosphere is explored in this dissertation. Radicals, although present in small concentrations in the atmosphere, play a significant role in creating and removing atmospheric pollution. As the atmosphere warms and consequently gets wetter, it is essential to understand the effects of water vapor on radical chemistry. This dissertation reports studies on the effects of water vapor on the kinetics of the self-reaction of β-hydroxyethyl peroxy radical (β-HEP), a prominent organic peroxy radical in the atmosphere. Both experimental and computational studies have been performed to examine the effects of water vapor on the kinetics …


Design, Fabrication, And Optimization Of Miniaturized Devices For Bioanalytical Applications, Suresh Kumar Aug 2015

Design, Fabrication, And Optimization Of Miniaturized Devices For Bioanalytical Applications, Suresh Kumar

Theses and Dissertations

My dissertation work integrates the techniques of microfabrication, micro/nanofluidics, and bioanalytical chemistry to develop miniaturized devices for healthcare applications. Semiconductor processing techniques including photolithography, physical and chemical vapor deposition, and wet etching are used to build these devices in silicon and polymeric materials. On-chip micro-/nanochannels, pumps, and valves are used to manipulate the flow of fluid in these devices. Analytical techniques such as size-based filtration, solid-phase extraction (SPE), sample enrichment, on-chip labeling, microchip electrophoresis (µCE), and laser induced fluorescence (LIF) are utilized to analyze biomolecules. Such miniaturized devices offer the advantages of rapid analysis, low cost, and lab-on-a-chip scale integration …


Ribosome Component Turnover Kinetics Describes A Two-Pool Kinetic Model In Dietary Restriction That Suggests Rpl10 Is Exchanged During Ribosome Lifespan, Andrew David Mathis Aug 2015

Ribosome Component Turnover Kinetics Describes A Two-Pool Kinetic Model In Dietary Restriction That Suggests Rpl10 Is Exchanged During Ribosome Lifespan, Andrew David Mathis

Theses and Dissertations

The eukaryotic ribosome is a large molecular machine consisting of ~80 ribosomal proteins and 4 rRNAs. The 40S and 60S ribosomal subunits are assembled in the nucleolus by ~200 helper proteins then shipped into the cytoplasm or to the endoplasmic reticulum where protein translation takes place. Eventually ribosomes are removed from the cytoplasm and recycled through ribophagy, however, very is little is known about ribosomal protein exchange after assembly but before ribophagy. Using kinetic turnover measurements of ribosomal proteins and rRNA in vivo we determined ribosomal protein replacement rates are diverse suggesting ribosomal components may be replaced without destruction of …


Dna Origami Stabilized And Seeded With 4'-Aminomethyltrioxsalen For Improved Dna Nanowire Fabrication, Matthew Paul Mcdowell Jul 2015

Dna Origami Stabilized And Seeded With 4'-Aminomethyltrioxsalen For Improved Dna Nanowire Fabrication, Matthew Paul Mcdowell

Theses and Dissertations

A fast emerging technology in the microelectronics field is bottom-up self-assembly of computer circuitry. A promising method to develop nanoelectronic devices through bottom-up self-assembly is the implementation of DNA-based technologies. Using DNA to create nanoelectronic devices is advantageous because of its already well understood base-paring and annealing qualities. These base-pairing and annealing qualities can be used to design and construct DNA nanostructures called DNA origami. DNA origami are specially designed structures made from single stranded DNA. Short single stranded DNA oligonucleotides called staple strands attach to a large single stranded DNA called a DNA scaffold. DNA staple strands and DNA …


Vector Intensity And Holography-Based Acoustic Source Characterization Of A Military Jet Aircraft, Trevor Alden Stout Jul 2015

Vector Intensity And Holography-Based Acoustic Source Characterization Of A Military Jet Aircraft, Trevor Alden Stout

Theses and Dissertations

The scientific community has employed multiple methods to analyze and describe the jet noise emanating from the turbulent exhaust flow from modern military aircraft engines, with the goal that better characterization of the sound radiation will improve noise reduction efforts. This thesis utilizes three different approaches to characterize the noise source region from a static F-22A Raptor. First, the energy flow field along planes near the aircraft and along an arc is measured using a multidimensional vector intensity probe. The resulting vector intensity maps give a clear indication of the directionality of the noise as a function of frequency at …


The Synthesis And Characterization Of Ferritin Bio Minerals For Photovoltaic, Nanobattery, And Bio-Nano Propellant Applications, Trevor Jamison Smith Jul 2015

The Synthesis And Characterization Of Ferritin Bio Minerals For Photovoltaic, Nanobattery, And Bio-Nano Propellant Applications, Trevor Jamison Smith

Theses and Dissertations

Material science is an interdisciplinary area of research, which in part, designs and characterizes new materials. Research is concerned with synthesis, structure, properties, and performance of materials. Discoveries in materials science have significant impact on future technologies, especially in nano-scale applications where the physical properties of nanomaterials are significantly different than their bulk counterparts. The work presented here discusses the use of ferritin, a hollow sphere-like biomolecule, which forms metal oxo-hydride nanoparticles inside its protein shell for uses as a bio-inorganic material.Ferritin is capable of forming and sequestering 8 nm metal-oxide nanoparticles within its 2 nm thick protein shell. A …


Progress Towards The Total Synthesis Of Yaku'amide A, Zhiwei Ma Jul 2015

Progress Towards The Total Synthesis Of Yaku'amide A, Zhiwei Ma

Theses and Dissertations

The synthetic progress towards yaku'amide A is described. The study leads to development of new synthetic methodologies. Base-free regioselective aminohydroxylation is convenient to deliver β-tert-hydroxyamino acids. A sequence consisting of alkylative esterification, Martin sulfurane mediated anti dehydration, a tandem azide reduction-O→N acyl transfer allows the rapid access of E- and Z-dehydroisoleucine-containing peptides from β-tert-hydroxyisoleucine derivatives. Those methods are effective in constructing complicated peptides and advanced subunits of yaku'amide A.


Analytical Approaches In Investigating The Kinetics Of Water-Molecule Complexes In Tropospheric Reactions, William J. Keeton Jul 2015

Analytical Approaches In Investigating The Kinetics Of Water-Molecule Complexes In Tropospheric Reactions, William J. Keeton

Theses and Dissertations

Ozone is a heavily monitored pollutant. Ozone is not directly emitted into the atmosphere, but rather the product of chemical reactions. Ground level ozone occurs when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react with each other in the presence of sunlight. The primary precursors of ozone are anthropogenically emitted, and as a result, tropospheric ozone has cost millions of dollars in damages and has hurt the health of countless people. This dissertation is a collection of work that aims to provide insight into atmospheric reactions that result in tropospheric ozone and the instrumentation to study such reactions. While …


Comparing Theory And Experiment For Analyte Transport In The First Vacuum Stage Of The Inductively Coupled Plasma Mass Spectrometer, Matthew R. Zachreson Jul 2015

Comparing Theory And Experiment For Analyte Transport In The First Vacuum Stage Of The Inductively Coupled Plasma Mass Spectrometer, Matthew R. Zachreson

Theses and Dissertations

The inductively coupled plasma mass spectrometer (ICP-MS) has been used in laboratories for many years. The majority of the improvements to the instrument have been done empirically through trial and error. A few fluid models have been made, which have given a general description of the flow through the mass spectrometer interface. However, due to long mean free path effects and other factors, it is very difficult to simulate the flow details well enough to predict how changing the interface design will change the formation of the ion beam. Towards this end, Spencer et al. developed FENIX, a direct simulation …


Histone Deacetylase 6 (Hdac6) Is Critical For Tumor Cell Survival And Promotes The Pro-Survival Activity Of 14-3-3Ζ Viadeacetylation Of Lysines Within The14-3-3Ζ Binding Pocket, Jeffrey Benjamin Mortenson Jul 2015

Histone Deacetylase 6 (Hdac6) Is Critical For Tumor Cell Survival And Promotes The Pro-Survival Activity Of 14-3-3Ζ Viadeacetylation Of Lysines Within The14-3-3Ζ Binding Pocket, Jeffrey Benjamin Mortenson

Theses and Dissertations

Our understanding of non-histone acetylation as a means of cellular regulation is in its infancy. Using a mass spectrometry approach we identified acetylated lysine residues and monitored acetylation changes across the proteome as a consequence of metabolic stress (hypoxia). We observed changes in acetylation status of non-histone lysines in tumor cells. Through the use of small molecule inhibitors of histone deacetylase enzymes (HDACs) and siRNA screening identified HDAC6 as a pro-survival regulator of lysine acetylation during hypoxia. The phospho-binding protein 14-3-3ζ acts as a signaling hub controlling a network of interacting partners and oncogenic pathways. We show here that lysines …


Geologic Mapping Of Ice Cave Peak Quadrangle, Uintah And Duchesne Counties, Utah With Implications From Mapping Laramide Faults, Gabriel J. Poduska Jul 2015

Geologic Mapping Of Ice Cave Peak Quadrangle, Uintah And Duchesne Counties, Utah With Implications From Mapping Laramide Faults, Gabriel J. Poduska

Theses and Dissertations

Geologic mapping (1:24,000 scale) of the Ice Cave Peak quadrangle, Uintah and Duchesne Counties, Utah has produced a better understanding of the geologic structures present in the quadrangle and has increased our understanding of faulting in northeastern Utah. Map units in the quadrangle range in age from late Neoproterozoic to Quaternary and include good exposures of Paleozoic rocks (Mississippian to Permian), limited exposures of Mesozoic rocks, and good exposures of Tertiary strata (Duchesne River Formation and Bishop Conglomerate) deposited during uplift of the Uinta Mountains. Lower Mississippian strata along the south flank of the Uinta Mountains have typically been mapped …


An Improved Classifier Chain Ensemble For Multi-Dimensionalclassification With Conditional Dependence, Joseph Ethan Heydorn Jul 2015

An Improved Classifier Chain Ensemble For Multi-Dimensionalclassification With Conditional Dependence, Joseph Ethan Heydorn

Theses and Dissertations

We focus on multi-dimensional classification (MDC) problems with conditional dependence, which we call multiple output dependence (MOD) problems. MDC is the task of predicting a vector of categorical outputs for each input. Conditional dependence in MDC means that the choice for one output value affects the choice for others, so it is not desirable to predict outputs independently. We show that conditional dependence in MDC implies that a single input can map to multiple correct output vectors. This means it is desirable to find multiple correct output vectors per input. Current solutions for MOD problems are not sufficient because they …


Amiens Cathedral: City Of God, Dennis West, Dr. Seth Holladay Jun 2015

Amiens Cathedral: City Of God, Dennis West, Dr. Seth Holladay

Journal of Undergraduate Research

What was it like to visit a gothic cathedral in the thirteenth century? That is the question that is explored in Amiens Cathedral: City of God. The purpose of this project was to illustrate the experience a medieval citizen of Amiens would have had upon visiting the Cathedral of Amiens. This was accomplished through researching dimensions and original construction of the cathedral, and illustrating how the stained glass and other art accentuates the sermons presented.


A Feasibility Study Of Photometric Reverberation Mapping With Meter-Class Telescopes, Carla June Carroll Jun 2015

A Feasibility Study Of Photometric Reverberation Mapping With Meter-Class Telescopes, Carla June Carroll

Theses and Dissertations

For the past several decades, mass estimates for supermassive black holes hosted by active galactic nuclei (AGN) have been made with the reverberation mapping (RM) technique. This methodology has produced consistent results and has been used to establish several relations that link the characteristics of the host galaxy to the mass of the central black hole. Despite this success, there are less than 50 AGN with black hole masses derived from RM. This low number is generally attributed to the difficulties in coordinating large blocks of telescope time for making simultaneous photometric and spectroscopic observations. Spectroscopic observations also generally require …


Characterization Of Order-Disorder Phase Transition Temperature For Select Nanoparticles, Gregory J. Sutherland Jun 2015

Characterization Of Order-Disorder Phase Transition Temperature For Select Nanoparticles, Gregory J. Sutherland

Theses and Dissertations

A method was found for creating ordered nanoparticles whose size and theoretical order-disorder temperature are ideal for study in the TEM. Specifically FePt, NiPt, FeNiPt and AuCu nanoparticles were studied. We were able to show how a nanoparticle's size affects its order-disorder temperature (Tod). When the particles were around 6 nm in diameter there was a shift downward of the Tod of 10-15 percent compared to the bulk. While particles around 10 nm in diameter experienced a downward shift of 0-6 percent compared to the bulk. One can approximate that particles less than 10-15 nm in diameter would show significant …


A Study Of Allylic Aminations As Catalyzed By Heterobimetallic Pd-Ti Complexes, Diana Lauren Ellis Jun 2015

A Study Of Allylic Aminations As Catalyzed By Heterobimetallic Pd-Ti Complexes, Diana Lauren Ellis

Theses and Dissertations

Heterobimetallic complexes present a unique approach to catalyzing challenging reactions. By having two metals in close proximity to each other, the metals are able to interact and alter their electronics in a way that simple organic ligands (carbon, nitrogen, sulfur etc.) cannot. Our studies of heterobimetallic complexes focus on a Pd–Ti complex. The complex features a dative interaction between the palladium and the titanium held together by a phosphonamide scaffold. This interaction increases the electrophilicity of the palladium and makes it a very suitable catalyst for allylic amination reactions. We have conducted extensive studies of this catalyst in allylic aminations, …


Nonlocally Maximal Hyperbolic Sets For Flows, Taylor Michael Petty Jun 2015

Nonlocally Maximal Hyperbolic Sets For Flows, Taylor Michael Petty

Theses and Dissertations

In 2004, Fisher constructed a map on a 2-disc that admitted a hyperbolic set not contained in any locally maximal hyperbolic set. Furthermore, it was shown that this was an open property, and that it was embeddable into any smooth manifold of dimension greater than one. In the present work we show that analogous results hold for flows. Specifically, on any smooth manifold with dimension greater than or equal to three there exists an open set of flows such that each flow in the open set contains a hyperbolic set that is not contained in a locally maximal one.


Topics Pertaining To The Group Matrix: K-Characters And Random Walks, Randall Dean Reese Jun 2015

Topics Pertaining To The Group Matrix: K-Characters And Random Walks, Randall Dean Reese

Theses and Dissertations

Linear characters of finite groups can be extended to take k operands. The basics of such a k-fold extension are detailed. We then examine a proposition by Johnson and Sehgal pertaining to these k-characters and disprove its converse. Probabilistic models can be applied to random walks on the Cayley groups of finite order. We examine random walks on dihedral groups which converge after a finite number of steps to the random walk induced by the uniform distribution. We present both sufficient and necessary conditions for such convergence and analyze aspects of algebraic geometry related to this subject.


Evaluation And Refinement Of Generalized B-Splines, Ian Daniel Henriksen Jun 2015

Evaluation And Refinement Of Generalized B-Splines, Ian Daniel Henriksen

Theses and Dissertations

In this thesis a method for direct evaluation of Generalized B-splines (GB-splines) via the representation of these curves as piecewise functions is presented. A local structure is introduced that makes the GB-spline curves more amenable to the integration used in constructing bases of higher degree. This basis is used to perform direct computation of piecewise representation of GB-spline bases and curves. Algorithms for refinement using these local structures are also developed.


Octahedral Extensions And Proofs Of Two Conjectures Of Wong, Kevin Ronald Childers Jun 2015

Octahedral Extensions And Proofs Of Two Conjectures Of Wong, Kevin Ronald Childers

Theses and Dissertations

Consider a non-Galois cubic extension K/Q ramified at a single prime p > 3. We show that if K is a subfield of an S_4-extension L/Q ramified only at p, we can determine the Artin conductor of the projective representation associated to L/Q, which is based on whether or not K/Q is totally real. We also show that the number of S_4-extensions of this type with K as a subfield is of the form 2^n - 1 for some n >= 0. If K/Q is totally real, n > 1. This proves two conjectures of Siman Wong.


Investigations Into Non-Degenerate Quasihomogeneous Polynomials As Related To Fjrw Theory, Scott C. Mancuso Jun 2015

Investigations Into Non-Degenerate Quasihomogeneous Polynomials As Related To Fjrw Theory, Scott C. Mancuso

Theses and Dissertations

The motivation for this paper is a better understanding of the basic building blocks of FJRW theory. The basics of FJRW theory will be briefly outlined, but the majority of the paper will deal with certain multivariate polynomials which are the most fundamental building blocks in FJRW theory. We will first describe what is already known about these polynomials and then discuss several properties we proved as well as conjectures we disproved. We also introduce a new conjecture suggested by computer calculations performed as part of our investigation.


Using Declassified Satellite Imagery To Quantify Geomorphic Change: A New Approach And Application To Himalayan Glaciers, Joshua Michael Maurer Jun 2015

Using Declassified Satellite Imagery To Quantify Geomorphic Change: A New Approach And Application To Himalayan Glaciers, Joshua Michael Maurer

Theses and Dissertations

Himalayan glaciers are key components of earth's cryosphere, acting as hydrological reservoirs vital to many human and natural systems. Most Himalayan glaciers are shrinking in response to changing climate, which will potentially impact water resources, natural hazards, sea level rise, and many other aspects. However, there is much uncertainty regarding the state of these glaciers, as direct field data are difficult to obtain. Accordingly, long-timespan remote sensing techniques are needed to measure changing glaciers, which have memory and often respond to climate on decadal timescales. This study uses declassified historical imagery from the Hexagon spy satellite database to fulfill this …


Studies On The Roles Of Translationally Recoded Proteins From Cyclooxygenase-1 And Nucleobindin Genes In Autophagy, Jonathan J. Lee Jun 2015

Studies On The Roles Of Translationally Recoded Proteins From Cyclooxygenase-1 And Nucleobindin Genes In Autophagy, Jonathan J. Lee

Theses and Dissertations

Advances in next-generation sequencing and ribosomal profiling methods highlight that the proteome is likely orders of magnitude larger than previously thought. This expansion potentially occurs through translational recoding, a process that results in the expression of multiple variations of a protein from a single messenger RNA. Our laboratory demonstrated that cyclooxygenase-3/1b (COX-3/1b), a frameshifted, intron-1-retaining, alternative splice variant from the COX-1 gene, is multiply recoded, which results in the translation of at least seven different COX-3 proteins. Two of the recoded COX-3 proteins that we identified are active prostaglandin synthases and are inhibited by non-steroidal anti-inflammatory drugs (NSAIDs). Here we …


Analysis Of Multiple Collision-Based Periodic Orbits In Dimension Higher Than One, Skyler C. Simmons Jun 2015

Analysis Of Multiple Collision-Based Periodic Orbits In Dimension Higher Than One, Skyler C. Simmons

Theses and Dissertations

We exhibit multiple periodic, collision-based orbits of the Newtonian n-body problem. Many of these orbits feature regularizable collisions between the masses. We demonstrate existence of the periodic orbits after performing the appropriate regularization. Stability, including linear stability, for the orbits is then computed using a technique due to Roberts. We point out other interesting features of the orbits as appropriate. When applicable, the results are extended to a broader family of orbits with similar behavior.


Synthesis, Rna Binding And Antibacterial Studies Of 2-Dos Mimetics And Development Of Polymer Supported Nanoparticle Catalysts For Nitroarene And Azide Reduction, Venkata Reddy Udumula Jun 2015

Synthesis, Rna Binding And Antibacterial Studies Of 2-Dos Mimetics And Development Of Polymer Supported Nanoparticle Catalysts For Nitroarene And Azide Reduction, Venkata Reddy Udumula

Theses and Dissertations

Project I 2-Deoxystreptamine (2-DOS), the most conserved central scaffold of aminoglycosides, is known to specifically recognize the 5'-GU-'3 sequence step through highly conserved hydrogen bonds and electrostatic interactions within and without the context of aminoglycosides (Figure 1a). We proposed that a novel monomeric unnatural amino acid building block using 2-DOS as a template would allow us to develop RNA binding molecules with higher affinity and selectivity than those currently available. Conjugating two or more of the monomeric building blocks by an amide bond would introduce extra hydrogen bonding donors and acceptors that are absent in natural aminoglycosides and increase specificity …


Bayesian Model For Antarctic Accumulation And Proposing Field Measurement, Philip White, Shane Reese May 2015

Bayesian Model For Antarctic Accumulation And Proposing Field Measurement, Philip White, Shane Reese

Journal of Undergraduate Research

Antarctica’s significance to the global climate is due to the vast amounts of water stored in its ice sheet. Indeed, its ice sheet stores enough water to increase the global sea level by about 200 feet if it were to melt. Even though radical climate change could not melt the entire Antarctic ice sheet for thousands of years, smaller, more realistic changes would still make a significant impact in the global climate, sea level, and growing seasons. For this reason, climatologists and geologists model water accumulation and loss over the Antarctic ice sheet. Accumulation, as defined here, is the net …


Look Sharp! How Eye Tracking And Memory Explain Susceptibility To Phishing, Ian Jones, Anthony Vance May 2015

Look Sharp! How Eye Tracking And Memory Explain Susceptibility To Phishing, Ian Jones, Anthony Vance

Journal of Undergraduate Research

Warning messages are one of the last lines of defense in computer security and are fundamental to users’ security interactions with technology. Consequently, researchers have actively sought to understand how users interact with security warnings and why warnings are so pervasively ignored. A key contributor to the disregard of security warnings is habituation—i.e., the diminishing of attention because of frequent exposure to warning. Although habituation has been inferred as a factor in many security-warning studies, little research has examined habituation in the context of security directly because habituation as a mental state is difficult to observe using conventional methods. …