Physical Sciences and Mathematics Commons^™

Design And Simulation Of A Miniature Cylindrical Mirror Auger Electron Energy Analyzer With Secondary Electron Noise Suppression, Jay A. Bieber

USF Tampa Graduate Theses and Dissertations

In the nanoscale metrology industry, there is a need for low-cost instruments, which have the ability to probe the structrure and elemental composition of thin films. This dissertation, describes the research performed to design and simulate a miniature Cylindrical Mirror Analyzer, (CMA), and Auger Electron Spectrometer, (AES). The CMA includes an integrated coaxial thermionic electron source. Electron optics simulations were performed using the Finite Element Method, (FEM), software COMSOL. To address the large Secondary Electron, (SE), noise, inherent in AES spectra, this research also included experiments to create structures in materials, which were intended to suppress SE backgound noise in …

Resolving Chronological And Temperature Constraints On Antarctic Deglacial Evolution Through Improved Dating Methodology, Cristina Subt

USF Tampa Graduate Theses and Dissertations

In order to determine the timing of Antarctic ice sheet retreat and advance during the Late Quaternary, various tools are used to measure the age of marginal marine sediments. Carbonate 14C dating is a well-established approach, but requires foraminiferal microfossils, shells or other carbonate materials that are rare in most Antarctic regions, and may also suffer from vital effects, which can result in variability of up to 500 years in living organisms. Bulk acid insoluble organic (AIO) 14C dates are frequently as an alternative, but this approach works best where high productivity and sedimentation rates reign, and not too well …

Bayesian Inference On Quantile Regression-Based Mixed-Effects Joint Models For Longitudinal-Survival Data From Aids Studies, Hanze Zhang

USF Tampa Graduate Theses and Dissertations

In HIV/AIDS studies, viral load (the number of copies of HIV-1 RNA) and CD4 cell counts are important biomarkers of the severity of viral infection, disease progression, and treatment evaluation. Recently, joint models, which have the capability on the bias reduction and estimates' efficiency improvement, have been developed to assess the longitudinal process, survival process, and the relationship between them simultaneously. However, the majority of the joint models are based on mean regression, which concentrates only on the mean effect of outcome variable conditional on certain covariates. In fact, in HIV/AIDS research, the mean effect may not always be of …

Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs

USF Tampa Graduate Theses and Dissertations

This dissertation consists of three projects utilizing electric and electromagnetic (EM) methods to better understand critical-zone hydrogeologic conditions in select Florida wetlands and waters.

First, a time-lapse electrical resistivity (ER) survey was conducted in section of mangrove forest on a barrier island in southeast Florida to image changes in pore-water salinity in the root zone. ER data show the most variability in the root zone over a 24-hour period, and, generally, the ground is more resistive during the day than overnight.

Second, a suite of three-dimensional forward models, based on varying lateral boundaries and conductivities typical of a coastal wetland, …

Investigating Marine Resources In The Gulf Of Mexico At Multiple Spatial And Temporal Scales Of Inquiry, Joshua Paul Kilborn

USF Tampa Graduate Theses and Dissertations

The work in this dissertation represents an attempt to investigate multiple temporal and spatial scales of inquiry relating to the variability of marine resources throughout the Gulf of Mexico large marine ecosystem (Gulf LME). This effort was undertaken over two spatial extents within the greater Gulf LME using two different time-series of fisheries monitoring data. Case studies demonstrating simple frameworks and best practices are presented with the aim of aiding researchers seeking to reduce errors and biases in scientific decision making. Two of the studies focused on three years of groundfish survey data collected across the West Florida Shelf (WFS), …

The Performance Of Multilevel Structural Equation Modeling (Msem) In Comparison To Multilevel Modeling (Mlm) In Multilevel Mediation Analysis With Non-Normal Data, Thanh Vinh Pham

USF Tampa Graduate Theses and Dissertations

The mediation analysis has been used to test if the effect of one variable on another variable is mediated by the third variable. The mediation analysis answers a question of how a predictor influences an outcome variable. Such information helps to gain understanding of mechanism underlying the variation of the outcome. When the mediation analysis is conducted on hierarchical data, the structure of data needs to be taken into account. Krull and MacKinnon (1999) recommended using Multilevel Modeling (MLM) with nested data and showed that the MLM approach has more power and flexibility over the standard Ordinary Least Squares (OLS) …

Assessing The Impact Of Land Use And Travel On Carbon Dioxide Emissions In Portland, Oregon, Zakari Mumuni

Dissertations and Theses

The negative consequences of sprawling metropolitan regions have attracted attention in both academia and in practice regarding how to better design settlements and alter travel behavior in a quest to curtail vehicle emissions. Studies that have attempted to understand the nexus between land use, travel and vehicle emissions have not been able to address the issue of self-selection in a satisfactory manner. Self-selection occurs when households choose their residential location based, in part, on expected travel behavior. This non-random experience makes the use of traditional regression frameworks that strongly rely on random sampling, unsuitable. This replication study's purpose was to …

Gw151226: Observation Of Gravitational Waves From A 22-Solar-Mass Binary Black Hole Coalescence, B. P. Abbott, K. Gill, B. Hughey, M. J. Szczepanczyk, M. Zanolin, Et Al.

Michele Zanolin

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5 σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 …

Search For Transient Gravitational Waves In Coincidence With Short-Duration Radio Transients During 2007-2013, B. P. Abbott, K. Gill, B. Hughey, D. Stiles, M. Szczepańczyk, M. Zanolin, Et Al.

Michele Zanolin

We present an archival search for transient gravitational-wave bursts in coincidence with 27 single pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo and GEO interferometer network. We also discuss a check for gravitational-wave signals in coincidence with Parkes Fast Radio Bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short-duration radio signals and transient gravitational-wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational-wave emission in coincidence with these radio transients was found, …

Observing Gravitational-Wave Transient Gw150914 With Minimal Assumptions, B. P. Abbott, K. Gill, B. Hughey, M. Szczepańczyk, M. Zanolin, Et Al.

Michele Zanolin

The gravitational-wave signal GW150914 was first identified on September 14, 2015, by searches for short-duration gravitational-wave transients. These searches identify time-correlated transients in multiple detectors with minimal assumptions about the signal morphology, allowing them to be sensitive to gravitational waves emitted by a wide range of sources including binary black hole mergers. Over the observational period from September 12 to October 20, 2015, these transient searches were sensitive to binary black hole mergers similar to GW150914 to an average distance of ∼600  Mpc. In this paper, we describe the analyses that first detected GW150914 as well as the parameter estimation …

The Santa Clara, 2017-11-16, Santa Clara University

The Santa Clara

No abstract provided.

Evolution Of Galactic Outflows At Z ~ 0–2 Revealed With Sdss, Deep2, And Keck Spectra, Yuma Sugahara, Masami Ouchi, Lihwai Lin, Crystal L. Martin, Yoshiaki Ono, Yuichi Harikane, Takatoshi Shibuya, Renbin Yan

Physics and Astronomy Faculty Publications

We conduct a systematic study of galactic outflows in star-forming galaxies at z ~ 0–2 based on the absorption lines of optical spectra taken from SDSS DR7, DEEP2 DR4, and Keck (Erb et al.). We carefully make stacked spectra of homogeneous galaxy samples with similar stellar mass distributions at z ~ 0–2 and perform the multicomponent fitting of model absorption lines and stellar continua to the stacked spectra. We obtain the maximum (v_max) and central (v_out) outflow velocities and estimate the mass loading factors (η), a ratio of the mass outflow rate …

An Advanced Private Social Activity Invitation Framework With Friendship Protection, Weitian Tong, Lei Chen, Scott Buglass, Weinan Gao

Department of Information Technology Faculty Publications

Due to the popularity of social networks and human-carried/human-affiliated devices with sensing abilities, like smartphones and smart wearable devices, a novel application was necessitated recently to organize group activities by learning historical data gathered from smart devices and choosing invitees carefully based on their personal interests. We proposed a private and efficient social activity invitation framework. Our main contributions are (1) defining a novel friendship to reduce the communication/update cost within the social network and enhance the privacy guarantee at the same time; () designing a strong privacy-preserving algorithm for graph publication, which addresses an open concern proposed recently; () …

Quaternary Sea-Level History And The Origin Of The Northernmost Coastal Aeolianites In The Americas: Channel Islands National Park, California, Usa, Daniel R. Muhs, Jeffrey S. Pigati, R. Randall Schumann, Gary L. Skipp, Naomi Porat, Stephen B. Devogel

United States Geological Survey: Staff Publications

Along most of the Pacific Coast of North America, sand dunes are dominantly silicate-rich. On the California Channel Islands, however, dunes are carbonate-rich, due to high productivity offshore and a lack of dilution by silicate minerals. Older sands on the Channel Islands contain enough carbonate to be cemented into aeolianite. Several generations of carbonate aeolianites are present on the California Channel Islands and represent the northernmost Quaternary coastal aeolianites on the Pacific Coast of North America. The oldest aeolianites on the islands may date to the early Pleistocene and thus far have only been found on Santa Cruz Island. Aeolianites …

Initial Mass Function Variability (Or Not) Among Low-Velocity Dispersion, Compact Stellar Systems, Alexa Villaume, Jean Brodie, Charlie Conroy, Aaron Romanowsky, Pieter Van Dokkum

Faculty Publications

Analyses of strong gravitational lenses, galaxy-scale kinematics, and absorption-line stellar population synthesis (SPS) have all concluded that the stellar initial mass function (IMF) varies within the massive early-type galaxy (ETG) population. However, the physical mechanism that drives variation in the IMF is an outstanding question. Here we use new SPS models to consider a diverse set of compact, low-velocity dispersion stellar systems: globular clusters (GCs), an ultra-compact dwarf (UCD), and the compact elliptical (cE) galaxy M32. We compare our results to massive ETGs and available dynamical measurements. We find that the GCs have stellar mass-to-light ratios (M/L) that are either …

Suitability Of River Delta Sediment As Proppant, Missouri And Niobrara Rivers, Nebraska And South Dakota, 2015, Ronald B. Zelt, Christopher M. Hobza, Bethany L. Burton, Nathaniel J. Schaepe, Nadine M. Piatak-Hackley

United States Geological Survey: Water Reports and Publications

Document abstract

Sediment management is a challenge faced by reservoir managers who have several potential options, including dredging, for mitigation of storage capacity lost to sedimentation. As sediment is removed from reservoir storage, potential use of the sediment for socioeconomic or ecological benefit could potentially defray some costs of its removal. Rivers that transport a sandy sediment load will deposit the sand load along a reservoir-headwaters reach where the current of the river slackens progressively as its bed approaches and then descends below the reservoir water level. Given a rare combination of factors, a reservoir deposit of alluvial sand has …

A Study Of The Urban Red Fox (Vulpes Vulpes) Population In Baton Rouge, Louisiana Using Social Media, Ahsennur Soysal

LSU Master's Theses

Foxes are timid yet resourceful animals that are integrated into many urban environments. Because they are elusive, collecting information about the number of urban foxes, their diet and spatial distribution, their interactions with the ecological community in their urban habitat, as well as residents’ response to them, is difficult. Involving stakeholders to participate in the data collection on wildlife via citizen science on social media is one way to overcome this complication, while simultaneously engaging residents in the ecology happening around them. Therefore, we used social media as the platform to engage the public to document and map the foxes …

Paleoenvironments, Origin, And Relative Maturity Of Organic Matter In Barremian-Aptian Limestones Of The Eastern Prada Quarry, Organyà Basin, Ne Spain, Jose R. Llaguno

FIU Electronic Theses and Dissertations

This study is a multi-proxy analysis of a 30-m section of a Barremian-Aptian succession of interbedded, grayish black (N2) and black (N1) limestones from a quarry of the Sierra de Prada. Index taxa include planktic foraminifera Globigerinelloides blowi and Hedbergella sigali, which combined with δ¹³C data from Cresmina and Gorgo a Cerbara sections indicate a late Barremian to early Aptian age. The rocks are organic-rich with 0.67 - 3.10 wt% total organic carbon (TOC). A marlstone interval (~1m) at 2.24 m has a low bioturbation index (1), TOC ~6.66 wt%, framboidal pyrite, and enrichment spikes of major, …

Efficient Pebble Game Algorithms Engineered For Protein Rigidity Applications, Mojtaba Nouri Bygi, Ileana Streinu

Computer Science: Faculty Publications

Pebble game rigidity analysis is an efficient method for extracting rigidity and flexibility information of biomolecules without performing costly molecular dynamics simulations. The standard algorithm works on a multi-graph associated to a mechanical model constructed from an arbitrary atom-bond network. Motivated by large scale protein flexibility and simulated unfolding applications, we have developed a faster and more robust variation tailored to the specificities of bio-polymers. We describe this new phased pebble game as implemented in the new version of our software Kinari-2.

Linking Taxonomic Diversity And Trophic Function: A Graph-Based Theoretical Approach, Marcella M. Jurotich, Kaitlyn Dougherty, Barbara Hayford, Sally Clark

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The purpose of this study is to develop a novel, visual method in analyzing complex functional trait data in freshwater ecology. We focus on macroinvertebrates in stream ecosystems under a gradient of habitat degradation and employ a combination of taxonomic and functional trait diversity analyses. Then we use graph theory to link changes in functional trait diversity to taxonomic richness and habitat degradation. We test the hypotheses that: 1) taxonomic diversity and trophic functional trait diversity both decrease with increased habitat degradation; 2) loss of taxa leads to a decrease in trophic function as visualized using a bipartite graph; and …

Metal-Organic Frameworks And Mof-Derived Carbon Materials For Fuel Cell Applications, Kia Williams

USF Tampa Graduate Theses and Dissertations

Rapid industrial globalization and technological development and energy consumption across the globe has significantly increased in response to mounting energy needs. The necessity for alternative and sustainable energy conversion devices has become apparent with the growth of energy utilization. In recent years, many research efforts have been made in the development of low-cost, efficient, environmentally friendly energy conversion devices. One type of energy conversion device, polymer electrolyte membrane fuel cells (PEMFCs), uses hydrogen oxidation at the anode and oxygen reduction at the cathode, with a solid-state proton conducting membrane between to generate energy with water as a by-product. PEMFCs use …

Design And Synthesis Of Cpg-Lytic Peptide Conjugate, Brachytherapy Beads And A Combinatorial Library Of Primary Amines Used As Potential Therapeutics In The Treatment Of Cancers, Josanne-Dee Woodroffe

USF Tampa Graduate Theses and Dissertations

Cancer remains one of the most feared diseases affecting the modern world. Second to heart disease, it is the largest cause of deaths, affecting one in three persons. Cancer cells are formed when normal, healthy cells become damage, losing their normal regulatory mechanism that control cell growth. There are many different types and progression of these cancer cells that determine the type of treatment a patient receives. The primary focus of this dissertation is to propose three studies of anticancer agents. In Chapter one, a CpG-lytic peptide conjugate was designed to target receptors on the cell membrane to concentrate the …

Generalized D-Kaup-Newell Integrable Systems And Their Integrable Couplings And Darboux Transformations, Morgan Ashley Mcanally

USF Tampa Graduate Theses and Dissertations

We present a new spectral problem, a generalization of the D-Kaup-Newell spectral problem, associated with the Lie algebra sl(2,R). Zero curvature equations furnish the soliton hierarchy. The trace identity produces the Hamiltonian structure for the hierarchy. Lastly, a reduction of the spectral problem is shown to have a different soliton hierarchy with a bi-Hamiltonian structure. The first major motivation of this dissertation is to present spectral problems that generate two soliton hierarchies with infinitely many commuting conservation laws and high-order symmetries, i.e., they are Liouville integrable.

We use the soliton hierarchies and a non-seimisimple matrix loop Lie algebra in order …

Design, Synthesis, Applications Of Polymers And Dendrimers, Alekhya Nimmagadda

USF Tampa Graduate Theses and Dissertations

WHO has reported that antibiotic resistance is the third major cause of human death all over the globe. Recent study, has focused on the development of new antibacterial resistance drugs. Herein, we tried to synthesis a series of polymers that can mimic the HDPs. HDPs can target the bacterial cell membrane and they have less chances to develop bacterial resistance. We synthesized the amphiphilic polycarbonates that are highly selective to Gram-positive bacteria, including multidrug resistant pathogens. The membrane disruption activity of these polymers was proved by fluorescence and TEM studies and the drug resistance study showed that the polymers don’t …

Usu Rayleigh-Scatter Lidar 2014-2015 Nightly Temperatures, Leda Sox, Vincent B. Wickwar, Tao Yuan

Browse all Datasets

Temperatures from a collocated Rayleigh-scatter lidar (RSL) and sodium resonance lidar were compared night-by-night, at different altitude levels, and hour-by-hour.

Three zipped files are provided.

USU RSL 2014-2015 [O] Corrected Temperatures.zip contains 36 files, one per night and hour, in RSLHourlyTemperaturesYYYYMMDDhour#.txt filename format.

USU RSL 2014-2015 Hourly Temperatures.zip contains 36 files, one per night and hour, in RSLHourlyTemperaturesYYYYMMDDhour#.txt filename format.

USU RSL 2014-2015 Nightly Temperatures.zip contains 19 files, one per night, in RSLTemperaturesYYYYMMDD.txt filename format.

Nilpotent Linear Transformations And The Solvability Of Power-Associative Nilalgebras, Ivan Correa, Irvin R. Hentzel, Pedro Pablo Julca, Luiz Antonio Peresi

Irvin Roy Hentzel

We prove some results about nilpotent linear transformations. As an application we solve some cases of Albert’s problem on the solvability of nilalgebras. More precisely, we prove the following results: commutative power-associative nilalgebras of dimension n and nilindex n − 1 or n − 2 are solvable; commutative power-associative nilalgebras of dimension 7 are solvable.

Nuclear Elements Of Degree 6 In The Free Alternative Algebra, Irvin R. Hentzel, L. A. Peresi

Irvin Roy Hentzel

We construct five new elements of degree 6 in the nucleus of the free alternative algebra. We use the representation theory of the symmetric group to locate the elements. We use the computer algebra system ALBERT and an extension of ALBERT to express the elements in compact form and to show that these new elements are not a consequence of the known degree-5 elements in the nucleus. We prove that these five new elements and four known elements form a basis for the subspace of nuclear elements of degree 6. Our calculations are done using modular arithmetic to save memory …

Solvability Of Commutative Right-Nilalgebras Satisfying (B (Aa)) A= B ((Aa) A), Ivan Correa, Alicia Labra, Irvin R. Hentzel

Irvin Roy Hentzel

We study commutative right-nilalgebras of right-nilindex four satisfying the identity (b(aa))a = b((aa)a). Our main result is that these algebras are solvable and not necessarily nilpotent. Our results require characteristic ≠ 2, 3, 5.

Invariant Nonassociative Algebra Structures On Irreducible Representations Of Simple Lie Algebras, Murray Bremner, Irvin R. Hentzel

Irvin Roy Hentzel

An irreducible representation of a simple Lie algebra can be a direct summand of its own tensor square. In this case, the representation admits a nonassociative algebra structure which is invariant in the sense that the Lie algebra acts as derivations. We study this situation for the Lie algebra sl(2).

The Nucleus Of The Free Alternative Algebra, Irvin R. Hentzel, L. A. Peresi

Irvin Roy Hentzel

We use a computer procedure to determine a basis of the elements of degree 5 in the nucleus of the free alternative algebra. In order to save computer memory, we do our calculations over the field Z103. All calculations are made with multilinear identities. Our procedure is also valid for other characteristics and for determining nuclear elements of higher degree.