Physical Sciences and Mathematics Commons^™

Evaluating Lithology As An Erosional Control On A Fluviokarst System In Northeastern Kentucky, Andrew K. Francis

Theses and Dissertations

Longitudinal stream profiles can be used to evaluate landscape evolution. Lithology as a control on a stream profile is especially of interests because fluviokarst systems are characterized by the contact of carbonate and non-carbonate rocks at the surface. Due to the difference in weathering processes between carbonates and non-carbonate rocks, it is likely that there is a difference in their rates of erosion. Cave Branch and its tributary Horn Hollow, are fluviokarst systems located in northeastern Kentucky. This area is primarily comprised of sandstone and limestone. The objectives of this study were to determine if variation in lithology was creating …

Simulation Of Value Stream Mapping And Discrete Optimization Of Energy Consumption In Modular Construction, Md Mukul Chowdhury

Theses and Dissertations

With the increased practice of modularization and prefabrication, the construction industry gained the benefits of quality management, improved completion time, reduced site disruption and vehicular traffic, and improved overall safety and security. Whereas industrialized construction methods, such as modular and manufactured buildings, have evolved over decades, core techniques used in prefabrication plants vary only slightly from those employed in traditional site-built construction. With a focus on energy and cost efficient modular construction, this research presents the development of a simulation, measurement and optimization system for energy consumption in the manufacturing process of modular construction. The system is based on Lean …

Women On The Board Of Directors And Their Impact On The Financial Performance Of A Firm: An Empirical Investigation Of Female Directors In The United States Technology Sector, Obinna Mogbogu

Theses and Dissertations

This study uses a sample of S&P 500 firms in the United States technology sector to investigate the likely relationship between female directors and financial performance of firms measured by return on average assets and return on average equity as the two accounting based measures of performance. Reasonable theoretical arguments drawn from resource dependency, human capital, agency, and social psychology theory, suggests that the gender diversity of the board of directors may have either a positive, negative, or neutral effect on the financial performance of the firm. Using nonparametric statistics approach, we find a small negative relationship between female directors …

Provenance Analysis Of Granite Cobbles In The Tiskilwa Till Using U -Pb Geochronology, Paul Antone Meister

Theses and Dissertations

U-Pb isotopic ages were determined for zircons extracted from granitic and related rocks in the Tiskilwa till to determine their origin. Crystalline cobbles (n = 750) were collected at localities from each of the four of the sub-lobes of the terminal Wisconsin moraines. Two sites were chosen from the Decatur, Peoria, and Princeton sub-lobes with one sample taken from the Harvard sub-lobe. Each sample was then individually processed, the zircons handpicked (n = 301), and geochronology conducted using LA-MC-ICPMS at the University of Arizona Laserchron Center. A Kolmogorov-Smirnov (K-S) statistical analysis show that all samples have identical zircon age spectra …

Takeover On The Tallgrass Prairie: How Lespedeza Cuneata Establishes Dominance, Morgan Rae Walder

Theses and Dissertations

Invasion ecology aims to study mechanisms by which invasive species are able to enter, establish, and spread within an ecosystem. This study analyzed Darwin’s naturalization and the biotic resistance hypotheses as the most likely explanations for invasion by an exotic legume, Lespedeza cuneata, into a tallgrass prairie. Darwin’s naturalization hypothesis posits that exotic species are less able to establish in communities that have related species, because similarity in morphology and function promotes intense competition for resources. The biotic resistance hypothesis states that competitors, herbivores, and pathogens already present in the community limit the colonization, naturalization, and persistence of invaders, therefore …

Synthesis And Characterization Of Polycyclic Aromatic Hydrocarbon ( Pah )-Porphyrin Hybrids, Ruixiao Gao

Theses and Dissertations

Carbaporphyrins are porphyrin analogs where one or more pyrrole units are replaced with a carbocyclic ring. Benziporphyrins are porphyrin analogues with a 1,3-phenylene unit replacing one of the pyrrole subunits. Because of cross-conjugation, benziporphyrins are not aromatic species. However, protonation of benziporphyrins can afford some aromatic characteristics. Although the synthesis of many examples of monocarbaporphyrins have been successfully executed, no examples of porphyrinoids with pyrene subunits have been prepared. Pyrene-containing porphyrinoids, which have been named as pyreniporphyrins, are theoretically significant molecules that provide insights into the aromaticity and reactivity of porphyrinoid systems.

In this thesis, two projects were conducted to …

Measurement Invariance And Psychometric Properties Of Career Indecision Profile-65 Scores: College Student And Non-College Samples, Casey J. Zobell

Theses and Dissertations

This thesis reports the results of a study conducted to examine psychometric properties of Career Indecision Profile-65 scores, including measurement invariance between college student and non-college samples. The responses of 529 college students and 472 non-college students to an online survey revealed that a four-factor structure fit the data in both samples well. Metric invariance was not supported. Six-week test-retest reliability was found to be high, and in the expected range. The tendency to maximize was found to be correlated strongly with one of the four factors. This study furthered the psychometric research for the Career Indecision Profile-65 and found …

A Gis Analysis Of Land Cover Effects On Water Systems: Nutrients And Algae In Stormwater Ponds, Nicole Lee Kappel

Theses and Dissertations

Anthropogenic land conversion is occurring rapidly and has the potential to impact our water quality. This study aims to explore the effect of watershed land characteristics on water quality within stormwater ponds (SWPs). Rapid land conversion is known to affect water quality of receiving water bodies, however not much is known about the effect of urbanization on SWPs. Geographic informational systems (GIS) was used to determine areas of land that drain into ponds. Water samples were collected and analyzed for total phosphorous, dissolved reactive phosphorous, nitrate, and ammonia. Algal pigment and percent cover measurements were taken in the field and …

Inhibitory Effects Of Unique Sulfonamides On Leishmania Tarentolae And Potential Pathway Of Inhibition, Jade M. Katinas

Theses and Dissertations

Leishmaniasis is an endemic disease caused by the protozoan parasite Leishmania. Current treatments for the parasite are limited by cost, availability, and drug resistance as the worldwide occurrence of leishmaniasis continues to be more prevalent. Sulfonamides are a class of compounds with medicinal properties that have been used to treat bacterial and parasitic diseases via various pathways. In this study, newly synthesized, unique structural analogs of sulfonamide compounds were assessed for their impact on Leishmania cell viability and potential pathways for inhibition were evaluated. Leishmania tarentolae (ATCC Strain 30143) axenic promastigote cells were grown in BHI medium and treated with …

Reducing Nitrate Pollution By Redirecting Farm Runoff Into The Subsurface Of An Herbaceous Riparian Buffer Zone., Tamru Girma Taye

Theses and Dissertations

In areas dominated by agricultural land use, excess nitrate is one of the leading contributors to water pollution. Tile drains, installed to drain crop root zones for maximum yield, fast track the introduction of nitrate-laden water into a nearby stream. Due to the risks elevated levels of nitrate pose to an ecosystem and its inhabitants, the following project explores a method of reducing nitrate pollution. One that can do it as close to the source of the pollution as possible.

A tile draining a 60acre farm in central Illinois was redirected to discharge its contents through subsurface flow into an …

On The Dynamics Of Boolean Gene Regulatory Networks With Stochasticity, Yuezhe Li

Theses and Dissertations

Genes are responsible for producing proteins that are essential to the construction of complex biological systems. The mechanisms by which this production is regulated have long been the center of wide spread research efforts. Deterministic Boolean gene regulatory models have been a particularly effective avenue of research in this field. However these models fall short of accounting for variations in the gene functionality due to the uncertain internal or external environmental conditions. One of the recent attempts to overcome this weakness is by (Murrugarra, 2012), in which a probabilistic component is introduced as the fixed activation/degradation propensities at the cellular …

Stream Energy Impacting Sediment Transport Through Low-Gradient Agricultural Streams, Paula Jane Pryor

Theses and Dissertations

Water quality can be severely impacted by increased sediment transport, particularly agriculturally-dominated systems like those found in central Illinois. Many low-gradient sediment studies focus on the fine material transported in suspension. However, coarse-material transport can be equally important for understanding sediment loads to surficial reservoirs for local drinking water. To address a general gap in knowledge of coarse-sediment transport through agricultural streams, seasonal changes and watershed differences in sediment transport were examined in a low-gradient system. This was accomplished through the installation of bedload traps, scour-fill markers, and bank erosion pins at two streams, Six Mile Creek and Money Creek …

Solid State Synthesis And Characterization Of The Rare Earth-Free Anti-Perovskites Sr2.5-Xba0.5 Al1-Xp Xo4 F ( 0 ≤ X ≤ 0.15 ), Sr3al1-Xy Xo 4 F ( 0 ≤ X ≤ 1 ), And Sr2.5-X/2ba0.5 Al1-Xhfxo4 F ( 0 ≤ X ≤ 0.1 ) As Potential Phosphor Materials, Sean Thomas Keil

Theses and Dissertations

Typical lighting systems such as incandescent and fluorescent bulbs are common in homes but are rather inefficient compared to the newer light emitting diodes (LEDs). LED-based lamps can be constructed to generate white light by combining a red, green, and blue LED, or by using an LED light source (typically with a low wavelength) with a complimentary phosphor coating to produce white light. The latter, known as phosphor-conversion (PC) LEDs, is the primary focus of this research, looking specifically at rare earth-free options for these phosphor coatings.

Anti-perovskites are a potential lattice type for this type of conversion, in particular …

The Effects Of Tile-Drain Input On A Low-Gradient Agricultural Stream In Central Illinois: Using A Thermal End Member Mixing Model And A Statistical Analysis Approach, Zachary David Kisfalusi

Theses and Dissertations

Tile-drains remove excess water from agricultural fields and channel it directly to the nearest surface water body decoupling the system from the natural flow paths. One way to measure the effects tile drains have on streams is to monitor the thermal energy both upstream and downstream of the tile input. In the temperate climate, a stream’s thermal signature experiences large fluctuations seasonally along with small diurnal changes. In contrast, groundwater temperature does not show these small-scale changes, and the seasonal changes are often muted and lagged in comparison to surface water. This project aimed to quantify any thermal change to …

Surficial Geology And Provenance Of Glacial Deposits Of The Saybrook 7.5 Minute Quadrangle, Mclean County, Illinois, Ellyn S. Rickels

Theses and Dissertations

The glaciated landscape of much of Illinois is a product of the most recent glacial episode, which is characterized by a series of end moraines composed predominantly of till and deposited by ice flowing into Illinois from the east and northeast around 20,000 years before present time. Two separate projects were completed as part of this thesis to better understand the surficial geology and the source areas of glacial sediment in central Illinois: the creation of a surficial geologic map of the Saybrook 7.5 Minute Quadrangle and a provenance study of granitic clasts from two moraines in the area.

A …