Physical Sciences and Mathematics Commons^™

Evidence For Photoionization-Driven Broad Absorption Line Variability, Tinggui Wang, Chenwei Yang, Huiyuan Wang, Gary J. Ferland

Physics and Astronomy Faculty Publications

We present a qualitative analysis of the variability of quasar broad absorption lines using the large multi-epoch spectroscopic data set of the Sloan Digital Sky Survey Data Release 10. We confirm that variations of absorption lines are highly coordinated among different components of the same ion or the same absorption component of different ions for C ɪᴠ, Si ɪᴠ, and N ᴠ. Furthermore, we show that the equivalent widths (EWs) of the lines decrease or increase statistically when the continuum brightens or dims. This is further supported by the synchronized variations of emission and absorption-line EWs when the well-established intrinsic …

The Inferred Evolution Of The Cold Gas Properties Of Candels Galaxies At 0.5 < Z < 3.0, G. Popping, K. Caputi, S. C. Trager, Rachel S. Somerville, Avishai Dekel, Susan A. Kassin, Dale D. Kocevski, Anton M. Koekemoer, Sandra M. Faber, Henry C. Ferguson, A. Galametz, Norman A. Grogin, Yicheng Guo, Y. Lu, Arjen Van Der Wel, Benjamin J. Weiner

Physics and Astronomy Faculty Publications

We derive the total cold gas, atomic hydrogen, and molecular gas masses of approximately 24 000 galaxies covering four decades in stellar mass at redshifts 0.5 < z < 3.0, taken from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey survey. Our inferences are based on the inversion of a molecular hydrogen based star formation law, coupled with a prescription to separate atomic and molecular gas. We find that: (1) there is an increasing trend between the inferred cold gas (H i and H₂), H i, and H₂ mass and the stellar mass of galaxies down to stellar masses of 10⁸ M_⊙ already in place at z = 3; (2) the molecular fractions of cold gas increase with increasing stellar mass and look-back time; (3) there is hardly any evolution in the mean H i content of galaxies at fixed stellar mass; (4) the cold gas fraction and relative amount of molecular …

Disaggregating The Effect Of Drought And Heat Stress During Flowering On Spikelet Fertility In Rice, Lisa Straussberger

Graduate Theses and Dissertations

Due to rice’s wide geographic distribution, extending from 50°N to 35°S, rice is

forecasted to be the most vulnerable crop to warming global climates. Previous studies have

predicted lower rice yields and increasing rice yield variability due to higher frequencies of heat

stress events, and a higher variability in precipitation patterns due to global warming. As such,

understanding the effects of drought and heat stress intensity and frequency on rice yields is of

upmost importance to feeding the growing global population.

Given that drought and high-temperature stress often occur together, it is essential to

disaggregate the two individual stressors and …

Reservoir Characterization And Depositional System Of The Atokan Grant Sand, Fort Worth Basin, Texas, Victoria Wood

Graduate Theses and Dissertations

The Atokan Grant Sands are a tight gas sand play that would add new reserves to the Fort Worth Basin. The Fort Worth Basin is located in north-central Texas just west of Dallas, Texas. Within the basin, the study area consists of Denton, Wise, Tarrant, and Parker Counties in Texas. The basin is bounded to the north by the Red River Arch, to the west by the Bend Arch, to the south by the Llano uplift, to the east by the Ouachita structural front, and to the northeast by the Muenster Arch. The Grant Sands are approximately 1,500 ft stratigraphically …

Economic Feasibility Of Aquaponics In Arkansas, Leah Ashley English

Graduate Theses and Dissertations

Concerns regarding population growth and resource scarcity have led to a recent renaissance of food production research. Over the past few decades, scientists have discovered new and innovative methods for growing food that, cumulatively, may hold the key to efficiently and sustainably feeding an ever-increasing world population. One method, known as aquaponics, has shown promise as being a sustainable solution for producing food locally in all parts of the world. Although many studies have shown aquaponic food production to be technically feasible, there are relatively few studies concerning the economic feasibility of aquaponics in various regions. To determine whether aquaponics …

Validation Of Soil-Test-Based Phosphorus And Potassium Fertilizer Recommendations For Rice And Soybean, Matthew Scott Fryer

Graduate Theses and Dissertations

The science of soil-testing for nutrient management and fertilizer recommendations is widely accepted among scientists and agronomists. Although this science is unsurpassed in predicting soil nutrient availability, soil-test interpretations are seldom validated. Major research objectives for irrigated soybean [Glycine max (L.) Merr.] and direct-seeded, delayed-flood rice (Oryza sativa L.) were to: i) validate the accuracy of Mehlich-3 soil-test P (STP) and K (STK) interpretations and ii) published critical tissue-P and -K interpretations in predicting the yield response to fertilizer at different significance levels (p≤0.05 to 0.25), iii) examine how seed nutrient concentrations are influenced by fertilization and crop response to …

Paddling A Trail, Erin Jennings Gilleece

Graduate Theses and Dissertations

Paddling A Trail documents construction of the first water trail in Arkansas. The 15 minute film is narrated by Arkansas Canoe Club Conservation Chair Debbie Doss. It follows Doss, and other volunteers as they mark the Wattensaw Bayou Trail in Hazen, Arkansas. The film is co-narrated by Kristen Bartlow of the Arkansas Game and Fish Commission. The footage was shot over three days, in two different locations. These were the White River in Northwest Arkansas and Wattensaw Bayou in Hazen, AR. The film illustrates the positive role trails can have on the environment and local economies. More importantly, the film …

Thermodynamic Modeling Of Aqueous Geochemistry Of Chlorine Salts: Application To Stability And Habitability Of Liquid Brines On Mars, Amira Elsenousy

Graduate Theses and Dissertations

The WCL (Wet Chemistry Lab) instrument on board the Mars’s Phoenix Lander has identified the soluble ionic composition of the soil at the landing site. Two important ions were detected at the landing site; perchlorates (ClO4-) with a concentration of ~ 2.4 wt% and chlorides (Cl-) with a concentration of 0.54 wt%. Between chloride and perchlorate ions three other oxidized ions exist and called chlorine ions: hypochlorite ClO - (ox. state +1), chlorite ClO2- (ox. state +3) and chlorate ClO3- (ox. state +5). These oxidized ions might be existed as intermediate species on the surface of Mars but remained undetected. …

Dark Matter Halo Concentration And The Evolution Of Spiral Structure In N-Body, Barred Spiral Galaxies, Jazmin Esmeralda Berlanga Medina

Graduate Theses and Dissertations

Motivated by the evidence of relationships between pitch angle (the tightness of spiral arm structure in the disk), P, and various indicators of central mass concentration, as well as the theoretical relationship between halo mass concentration and the density of visible matter in the central part of the galaxy, we look at a possible relationship between P and cvir (the virial concentration of the dark matter halo) in N-body simulations of barred, spiral galaxies. We also look at the evolution of pitch angle over time in higher temporal resolution than any data currently available in the literature. We find that …

Message From The Vice President For Research, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2014, Daniel M. Dauer, Todd A. Egerton, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Cindy Johnson, Monika Arora

Status and Trends for Virginia Chesapeake Bay

The period prior to the implementation of the Chesapeake Bay Monitoring Program was characterized by a marked decline in the water quality of the Chesapeake Bay. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality (e.g. USEPA, 1982,1983;Officer et al.,1984; Orth and Moore, 1984). The results of concerted research efforts in the late 1970s and early 1980s stimulated the …

Rear-Flank Outflow Dynamics And Thermodynamics In The 10 June 2010 Last Chance, Colorado Supercell, Curtis J. Riganti

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

On 10 June 2010, the second Verification of the Origins of Tornadoes Experiment (VORTEX2) armada observed the non-tornadic phase of a supercell thunderstorm near Last Chance, Colorado. Tempest unmanned aircraft system (UAS) data collected in the rear-flank outflow revealed what appeared to be an elevated outflow head, turbulent wake, and a cold secondary outflow surge. Surface thermodynamic and kinematic data collected by StickNets and mobile mesonets suggested that the outflow wake may have extended to or very near the surface, perhaps cutting off the leading edge of the outflow at times. Single-Doppler data collected by the NOAA X-Pol Mobile Polarimetric …

Sequence Stratigraphic Framework Of Carbonate Diagenesis Within Neogene Glaciomarine Sandstones Of The Victoria Land Basin, Antarctica: Insights Into Reservoir Quality In Polar Settings, Daniel P. Dunham

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The controls on reservoir quality of most clastic sedimentary deposits are well-documented and understood. However, comparatively little is known about the reservoir potential of glaciogenic and glaciomarine deposits. This study investigates the Neogene strata of the AND-2A core recovered by the ANDRILL-Southern McMurdo Sound Project in the Victoria Land Basin, Antarctica, as an analog for assessing controls on reservoir quality in glaciomarine deposits. A petrographic analysis was conducted on 60 sandstone samples from various depths throughout the core, and carbonate diagenetic phases and morphologies were documented. Four sequences were examined in detail. Point counting on all samples was done to …

Estimation Of Deep Drainage Differences Between Till And No-Till Irrigated Agriculture, Justin P. Gibson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Deep drainage was monitored under two center pivot irrigation sites located in south-central Nebraska during the 2013, and part of the 2014, growing seasons. Both fields underwent similar land management except for tillage practice: no-till in one and disk till in the other. Long term deep drainage rates were also estimated from chemical analysis of extracted soil cores, with the aid of the chloride mass balance equation. Mechanisms underpinning differences in deep drainage between the two fields were investigated through the use of unsaturated zone numerical modeling.

Deep drainage estimates from field monitoring indicated that a greater amount of deep …

Effects Of Wind Turbine Noise On Male Greater Prairie-Chicken Vocalizations And Chorus, Cara E. Whalen

School of Natural Resources: Dissertations, Theses, and Student Research

Wind energy facilities are constructed without full knowledge of their effects on birds, and the noise generated by wind turbines is a particular concern. I investigated the effects of wind turbine noise on male Greater Prairie-Chicken (Tympanuchus cupido pinnatus) vocalizations and chorus near Ainsworth, NE, USA in 2013 and 2014. I studied 14 leks located in the area surrounding a 36-turbine wind energy facility. I used two main approaches in this study. First, I recorded Greater Prairie-Chicken boom, cackle, whine, and whoop vocalizations at each of the study leks and measured the duration, sound pressure level, peak frequency, …

Occupancy Analysis And Density Estimation Of Kori Bustards (Ardeotis Kori) And Helmeted Guineafowl (Numida Meleagris) For Use In Landscape Conservation Planning In The Northern Tuli Game Reserve, Botswana, Kathryn R. Mccollum

School of Natural Resources: Dissertations, Theses, and Student Research

For understudied species, more informed conservation planning and decision-making on both the local and landscape levels may be attained through the use of occupancy and abundance estimations. Here, we focus on two iconic bird species in eastern Botswana, kori bustards (Ardeotis kori) and helmeted guineafowl (Numida meleagris). The overall goal of this project was to better understand the hierarchy of factors that influence occupancy (ψ) and density of kori bustard and helmeted guineafowl populations within the Northern Tuli Game Reserve and how these factors may interact to affect landscape conservation and usage. We performed distance sampling …

Toward The Probing Of Dhqs Activity By Protein Engineering Through The Introduction Of Unnatural Amino Acids And The Selection Of Trna/Trna Synthetase Pairs, Shaina E. Ives

Department of Chemistry: Dissertations, Theses, and Student Research

Protein engineering is a valuable tool that allows scientist to explore how an enzyme works by mutation of key residues. This method has been used to improve function or stability of enzymes, thus allowing their use in both the lab and in industry to be expanded. Genetic incorporation of unnatural amino acids (unAA) can be used with protein engineering to exceed the current limitations, due to the limited number of functional groups of the 20 common amino acids.

The majority of this thesis will discuss the progress on incorporating the various unAA into the active site of the enzyme, Dehydroquinate …

Terahertz Radiation From High-Temperature Superconducting Bscco Mesas Of Various Geometries, Daniel P. Cerkoney

HIM 1990-2015

The purpose of this thesis is to examine the radiation from high-temperature superconducting mesas of Bi2Sr2CaCu2O8+ (BSCCO). This is motivated by the need for coherent sources of continuous wave terahertz (THz) emission capable of radiating practically in the THz frequency band. As BSCCO has been shown to be tunable from 0.5–2.4 THz (i.e., through the entire socalled terahertz gap centered about 1 THz), and has a higher peak operating temperature near 1 THz than most alternative sources, it is a good candidate for imaging and spectroscopy device applications [1]. When a static DC voltage is applied to a BSCCO mesa, …

To Hydrate Or Chlorinate: A Regression Analysis Of The Levels Of Chlorine In The Public Water Supply, Drew A. Doyle

HIM 1990-2015

Public water supplies contain disease-causing microorganisms in the water or distribution ducts. In order to kill off these pathogens, a disinfectant, such as chlorine, is added to the water. Chlorine is the most widely used disinfectant in all U.S. water treatment facilities. Chlorine is known to be one of the most powerful disinfectants to restrict harmful pathogens from reaching the consumer. In the interest of obtaining a better understanding of what variables affect the levels of chlorine in the water, this thesis will analyze a particular set of water samples randomly collected from locations in Orange County, Florida. Thirty water …

Coordination Chemistry In Biology And Medicine, Christopher Chu

Dissertations - ALL

PART I. Synthesis and Characterization of Novel Metal-Citrate Complexes and the Investigation of Metal-Citrate Transporters in Gram-Positive Bacteria

Abstract.

Syntheses of new barium, cadmium, calcium, cobalt, iron, lead, magnesium, manganese, nickel, and strontium citrate complexes have been attempted using different methods such as room temperature slow evaporation and hydrothermal reactions to create new metal-citrate complexes. Crystallizations were conducted under conditions varying metal and ligand concentrations, solution pH, temperature, solvents, and the presence of coligands. All structures of crystals obtained were characterized by X-ray crystallography. A novel lead-citrate complex was synthesized with a formula of (Na)[Pb5(C6H5O7)3(C6H6O7)(H2O)] 8H2O. The structure is two-dimensional …

Composite Minimization: Proximity Algorithms And Their Applications, Feishe Chen

Dissertations - ALL

ABSTRACT

Image and signal processing problems of practical importance, such as incomplete

data recovery and compressed sensing, are often modeled as nonsmooth optimization

problems whose objective functions are the sum of two terms, each of which is the

composition of a prox-friendly function with a matrix. Therefore, there is a practical

need to solve such optimization problems. Besides the nondifferentiability of the

objective functions of the associated optimization problems and the larger dimension

of the underlying images and signals, the sum of the objective functions is not,

in general, prox-friendly, which makes solving the problems challenging. Many algorithms have been …

Ruthenium-Catalyzed Transformations For The Synthesis Of Conjugated Dienes, Lauren Kaminsky

Dissertations - ALL

A general description of transition metal catalysis of alkynes and alkenes for the formation of conjugated dienes is briefly discussed. Specifically, a synopsis of ruthenium-hydride catalysis for the formation of 1,3-dienes is presented.

The development of the trans-silylvinylation of internal alkynes with acrylates and vinyl boronates to form conjugated dienes is discussed. This transformation was accomplished via a recently developed tandem silylative coupling using RuHCl(CO)(PCy3)2. The reaction optimization, mechanistic hypothesis and substrate scope for the coupling with acrylates and vinyl boronates is described. The vinyl boronate scope and alkyne scope is presented, in addition to the selective derivatization of the …

Optimizing Acyclic Identification Of Aptamers, Caitlin M. Miller

Dissertations - ALL

The minimal human alpha-thrombin binding aptamer, d(GGTTGGTGTGGTTGG), has previously been successfully identified from a DNA library of randomized hairpin loop, m=15, with the High Throughput Screening of Aptamers (HTSA) technique, later termed Acyclic Identification of Aptamers (AIA). AIA eliminated the need for multiple cycles of in vitro evolution typically used for aptamer discovery by employing libraries with an over-representation of all possible sequences and high throughput sequencing. Although the method was successful at identifying the thrombin binding aptamer, improvements to partitioning and sample preparation inconsistencies encountered during replication attempts were necessary in order to maximize its value. Subsequent revisions and …

Understanding Disordered Systems Through Numerical Simulation And Algorithm Development, Sean M. Sweeney

Dissertations - ALL

Disordered systems arise in many physical contexts. Not all matter is uni-

form, and impurities or heterogeneities can be modeled by fixed random disor-

der. Numerous complex networks also possess fixed disorder, leading to appli-

cations in transportation systems [1], telecommunications [2], social networks

[3, 4], and epidemic modeling [5], to name a few.

Due to their random nature and power law critical behavior, disordered

systems are difficult to study analytically. Numerical simulation can help

overcome this hurdle by allowing for the rapid computation of system states.

In order to get precise statistics and extrapolate to the thermodynamic limit,

large …

Ruthenium Hydride Catalyzed Silylvinylation Of Alkynes, Robert J. Wilson

Dissertations - ALL

The intermolecular ruthenium hydride catalyzed coupling of internal alkynes with subsequent insertion of olefin acceptors is described. This approach utilizes a vinyl silicon tether to provide complete regiocontrol, a stereoselective anti-exo-dig cyclization which affords a tetrasubstituted olefin with a new vinylsilane, and a highly functionalized Z,E diene motif. Subsequent studies for a highly selective intramolecular trans-silylvinylation of internal alkynes catalyzed by RuHCl(CO)(SIMes)(PPh3) is reported. The use of methyl vinyl ketone as an additive increased the efficiency of this transformation. This process was expanded upon using ethylene gas as an additive and provides a net 5-exo-dig trans-silylvinylation of internal alkynes. Ethylene …

Information Technology For Development In Small And Medium-Sized Enterprises, Jie Xiong, Sajda Qureshi

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Development is a concept that is often used to describe growth in organizations and the regions in which they reside. While research in Information Systems (IS) recognizes the importance of Information Technology (IT) in improving the organizational performance, a great deal of emphasis is given towards understanding large organizations. While social-economic development and transformation relies on new technological infrastructures and organizational changes, there is still a weak link between the organization studies with Information Technology (IT) as it relates to the growth of organizations. It appears that a greater research focus is needed in understanding the use of IT in …

Notes From The Director, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

About The Mcnair Scholars Program, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.

Mobilerp, Anthony Fata

Computer Engineering

MobilERP is a system that increases traceability of parts in a manufacturing process in a simple paperless way. The system contains three components, a desktop application, a mobile app, and a database. The mobile application allows employees to scan (using a bar code scanner) parts that they are working/finishing on during the manufacturing process. As the part goes down the assembly line, individuals will barcode scan using the app to track the progress. These changes would get updated to the database, where then the designated person can track the progress of the part as well as any problems or concerns …

Pthreads Profiler, Ryan Van Quinlan

Computer Science and Software Engineering

The goal of this senior project was to design and implement a program which would allow users to profile programs that utilize the Pthreads library. This profiler allows users to measure load balance and lock contention between threads as well as discover deadlocks. These tools can be essential to developers of multi-threaded applications, which are notoriously difficult to debug. Additionally, this tool can help find vital performance benefits by providing relative execution measurements. The profiler is written in C++ and utilizes the standard template library as well as glibc extensions.