Physical Sciences and Mathematics Commons^™

New Infrared Spectral Data For 27 Asteroids: An Investigation Of Meteorite-Asteroid Relationships By Using The Modified Gaussian Model, Katherine Marie Gietzen

Graduate Theses and Dissertations

Asteroids provide unique insights into the origin and early history of the solar system. Since asteroids are considered to be fairly pristine, studying them provides opportunities to learn more about the primordial solar system, its materials, processes and history. Since the discovery in 1801 of the first asteroid, Ceres, during the era when everyone was searching for the "missing planet", astronomers have been trying to understand what they are, where they came from, why they exist and what they can tell us about how our solar system formed and evolved.

Within the asteroid population are a number of sub-populations, the …

Evaluation Of Best Management Practices To Reduce Nutrients Runoff In Watersheds In Arkansas, Hector German Rodriguez Diaz

Graduate Theses and Dissertations

There are many non point sources (NPS) of pollution issues across the state of Arkansas. Each region of the state has different concerns. Many watersheds have been included in the Arkansas's 2008 303(d) list for NPS impairments with sediment and nutrients being the primary causes of concern. This research hypothesized that there are no cost or net returns risks when adopting best management practices (BMPs) to control nutrients runoff and that selection, timing, placement and cost have no impact on the implementation of BMPs. Using two priority watersheds, the L'Anguille River and the Lincoln Lake, as examples, the environmental benefits …

White River Forum Ii: Second Annual Meeting Of The White River Forum, John Havel, Kenneth Steele

Technical Reports

This second annual meeting of the White River Forum is proof of widespread interest in the water quality of the Upper White River watershed. The participation of numerous elected officials, state and federal agencies, universities, businesses, and local citizens indicates that interest in understanding policy issues crosses political boundaries and occupations.

Describing The Economic Impact Of The Oil And Gas Industry In Arkansas, Katherine A. Deck, Viktoria Riiman

Publications and Presentations

The Arkansas oil and natural gas industries are increasingly important to the state’s economic vitality. As global demand for energy increases, domestic production is put into the spotlight. This study describes the economic impact of the oil and gas industries in Arkansas, focusing on the sector’s economic output, employment, and tax revenues.

Factors Affecting Redox Magnetohydrodynamics For Flow In Small Volumes, Matthew D. Gerner

Graduate Theses and Dissertations

Lab-on-a-chip technologies offer the possibility of developing analytical devices that are low-cost, portable, disposable, fast, and operable by non-technical personnel. Such devices require automated methods to manipulate ultra-small volumes (picoliters) of samples and solution, including pumping, stirring, and positioning. Current methods for ultra-small volume microfluidics have limitations that restrict their use including high voltage requirements, disadvantageous flow profiles or rates, and relatively complicated fabrication due to mechanical parts. Redox magnetohydrodyanmics (RMHD) that utilizes permanent magnets for portability shows promise as a micropump with ease of switching flow direction, no moving parts, compatibility with both aqueous and non-aqueous solutions, low voltages …

Water Quality Sampling, Analysis And Annual Load Determinations For Nutrients And Solids On The Ballard Creek, 2008, L.B. Massey, L.W. Cash, B.E. Haggard

Technical Reports

The Arkansas Water Resources Center monitored water quality at Ballard Creek at the Washington County Road 76 Bridge in northwest Arkansas during base flow and storm events from July 1, 2008 through June 30, 2009. Water samples were collected manually or with an auto-sampler and analyzed for nitrate-nitrogen, ammonia-nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, sulfate, chloride and total suspended solids. Instantaneous stage and discharge were recorded at the site; total annual discharge was 55,800,000 m³ , with 27% attributed to base flow and 73% attributed to storm flow. Loads were estimated using the mid-interval integration approach using continuous …

Illinois River Volunteer Monitoring, L.B. Massey, B.E. Haggard

Technical Reports

Understanding how water quality conditions change along a land use gradient and over time is important for sustainable watershed management. Therefore, a volunteer monitoring program was created to measure water chemistry at 37 established sites within the Upper Illinois River Watershed and to evaluate changes in water chemistry over the past 15 years. The Illinois River Watershed Partnership (IRWP), a non‐profit organization subcontracted with the Arkansas Water Resources Center at the University of Arkansas, to manage the volunteer monitoring project, train volunteers to collect samples following EPA approved methods, and to analyze the collected samples. The AWRC trained 27 volunteers …

Heterosternuta Sulphuria (Coloptera: Dytiscidae) Occurence In The Sulphur Springs Headwater System And In Buffalo National River Tributaries (Arkansas, Usa): Current Distribution, Habitat Conditions, And Biomonitoring Framework, S.D. Longing, B.E. Haggard

Technical Reports

Heterosternuta sulphuria is an endemic aquatic species of concern in Arkansas, with a priority score of 80 out of 100 and a conservation rank of S1and G1. A need of the Arkansas Wildlife Action Plan (AWAP) was to obtain baseline information on distribution and population status of H. sulphuria. Here, we report new H. sulphuria records for 39 sites across 10 counties in the Ozark Highlands and Boston Mountain ecoregions and a determined habitat type of shallow margins and small bedrock pools of perennial streams and spring seeps. Few habitat patches were observed per site because detection was typically rapid …

Water Quality Sampling, Analysis And Annual Load Determinations For The Illinois River At Arkansas Highway 59 Bridge, 2008, L.B. Massey, L.W. Cash, B.E. Haggard

Technical Reports

The Arkansas Water Resources Center monitored water quality at the Illinois River at the Arkansas Highway 59 Bridge, just upstream from the Arkansas-Oklahoma state border during base flow and storm events from July 1, 2008 through June 30, 2009. Water samples were collected manually or with an auto-sampler and analyzed for nitrate-nitrogen, ammonia-nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, sulfate, chloride and total suspended solids. The U.S. Geological Survey recorded instantaneous stage and discharge at the site, total annual discharge was 1,010,000,000 m³ , with 37% attributed to base flow and 63% attributed to storm flow. Loads were estimated …

Frequency Distributions Of Median Nutrient And Chlorophyll Concentrations Across The Red River Basin, 1996-2006, S.D. Longing, B.E. Haggard

Technical Reports

Acquisition and compilation of water quality data for a ten year time period (1996 – 2006) from 589 stream and river stations was conducted to support nutrient criteria development for the multi–state Red River Basin shared by Arkansas, Louisiana, New Mexico, Oklahoma and Texas, USA. Twenty–three water quality parameters were collected from five data sources (USGS, ADEQ, LDEQ, OCC, OWRB, and TCEQ) and an additional 13 parameters were acquired from at least one source. Data for the primary biological parameter of interest, chlorophyll a, was sparse and available from only two sources. Following compilation of data, medians were calculated for …

Understanding Sources And Consequences Of Variation In Self-Assembly, Arjun Dasgupta

Computer Science and Computer Engineering Undergraduate Honors Theses

Self-assembly is the process of constructing a larger structure from small component parts that randomly collide and bond through weak interactions [2]. It is a potentially important method in the field of nanoscale manufacturing. However, because of the nature of self-assembly, randomness and the design of self-assembly compete with each other, and unforeseen things can be produced. In this thesis, the tiling assembly model of Winfree [7] was simulated. The tiling assembly model has two bonds which assemble planar nanostructures. The goal of the simulations was to determine what probabilities would produce an average degree of four (the ideal) for …

Imaging Second-Harmonic Radiation And Scattering Patterns In Zno Micro/Nanostructures, Katrina Marie Geren

Graduate Theses and Dissertations

The optical characteristics of ZnO nanostructures have recently garnered interest due to the inclusion of these structures in many nanoscale optical and optoelectronic devices. This thesis will address several characteristics involving second harmonic generation and scattering in ZnO nano- and microstructures. A method will be presented for determining the nonlinear coefficients of the second order susceptibility in a single ZnO rod. This method uses transmission geometry where previous methods have employed back-reflected irradiation. The nonlinear coefficients found using this new technique were consistent with previous data from similar structures. Models will be presented for predicting the second harmonic scattering patterns …

Modeling Of Compositionally Graded Barium Strontium Titanate From First Principles, Laura Elizabeth Walizer

Graduate Theses and Dissertations

"Barium Strontium Titanate (BaxSr1-xTiO3 or BST) is a Perovskite alloy of interest for both technological and intellectual reasons. Its ferroelectric and piezoelectric properties make it useful in a variety of electric components such as transducers and actuators, and BST in particular is a material of interest for the development of a ferroelectric RAM for computers. The inclusion of SrTiO3, an incipient ferroelectric, and the fact that the properties of a BST system depend strongly on its relative composition of BaTiO3 and SrTiO3 (ST), make also this a material of high interest. Compositionally graded systems are of further interest , partly …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2008, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts also be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts.

E-85 Vs. Regular Gasoline: Effects On Engine Performance, Fuel Efficiency, And Exhaust Emissions, Jordan W. Steinhaus, Donald M. Johnson, George W. Wardlow

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

This study compared the performance, fuel efficiency, and exhaust emissions of a 2.61 kW engine fueled with regular unleaded gasoline (87 octane) and an 85% ethanol blend (E85) under two load conditions. Four 1-h tests were conducted with each fuel at both governor’s maximum (3400 rpm) and peak torque (2800 rpm) conditions for a total of 16 tests. At governor’s maximum engine speed, there were no significant differences (p>0.05) between fuels for engine torque, power, specific carbon dioxide (sCO2 ), specific carbon monoxide (sCO), specific hydrocarbons (sHC), or specific oxides of nitrogen (sNOX) emissions. However, there was a significant …

Microwave Synthesis Of Cis-Dichlorotetrakis(Dimethylsulfoxide)Ruthenium(Ii), A. Harvey, Mark Draganjac, S. Chui, R. Snell, E. Benjamin

Journal of the Arkansas Academy of Science

No abstract provided.

Dna Sequence Analysis Of Freshwater Eustigmatophyceae, A Potential Source Of Essential Fatty Acids, Sara E. Prior, M. W. Fawley, K. P. Fawley

Journal of the Arkansas Academy of Science

Freshwater Eustigmatophyceae are a group of microalgae that are considered rare and of low diversity, with only a few genera and species in a single order. Some Eustigmatophyceae produce fatty acids that are important nutrients for aquaculture, as well as for human food consumption. In addition, some Eustigmatophyceae produce hydrocarbons that may be useful in biofuel production. In our studies of the diversity of coccoid algae from Itasca State Park, Minnesota, we discovered several isolates that we tentatively identified as Eustigmatophyceae. Preliminary molecular characterization indicated that these isolates were highly diverse and probably represented species new to science. In this …

Development Of A Distributed Artificial Neural Network For Hydrologic Modeling, Rebecca Logsdon

Inquiry: The University of Arkansas Undergraduate Research Journal

Hydrological models are used to represent the rainfall-runoff and pollutant transport mechanisms within watersheds. Accurate representation of these dynamic and complex natural processes within a watershed is an important step in managing and protecting a watershed Artificial neural network (ANN) models are often used in hydrologic modeling. Typical ANN models are trained to use lumped data. However, watershed characteristics used as inputs in hydrological modeling are spatially and often temporally dynamic. Therefore, a lumped model does not have the ability to represent changes in spatial dynamics of a watershed. Therefore, the purpose of this study was to develop and test …

The Beauty Of Mathematics And The Mathematics Of Beauty: Continued Fractions And The Golden Ratio, Jessica Tush

Inquiry: The University of Arkansas Undergraduate Research Journal

This project begins with a look at the history of simple continued fractions and how we have arrived where we are today. We then move through a study of simple continued fractions, beginning first with rational numbers and moving to irrational numbers. Continuing further in the pursuit of joining mathematics and art, we define the specific continued fraction that gives rise to the Fibonacci sequence and the Golden Ratio~ (phi, pronounced 'Jai"). These two notions form a direct link to art and the properties that we hope to examine. I have taken an analytic approach to showing that the Golden …

Carbon Nanotube Cluster Based Micro-Fluidic System For Bacteria Capture, Concentration, And Separation, Chris Nelson

Inquiry: The University of Arkansas Undergraduate Research Journal

Disease-causing pathogens continue presenting enormous global health problems, especially due to their easy transmittance to people via water supply systems. The detection, filtration, and purification of bacteria-contaminated water samples are complex activities, ones subject to considerable error. Here we present a new and highly effective micro-fluidic system with carbon nanotube (CNT) clusters for effective and efficient detection, filtration, and purification of bacteria-contaminated medium. The developed system is based upon two unique properties of CNT clusters: high bacterial affinity and magnetic susceptibility. The CNTs 'high affinity to bacteria cells makes them a key candidate for the bacteria adsorption. The magnetic susceptibility …

Measurement Of Transient Smoke Emissions From Diesel And Biodiesel Fuel Blends In An Agricultural Tractor, Kristin M. Pennington, Sonia R. Munoz, Donald M. Johnson, George Wardlow

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Transient smoke emissions pose potential hazards to human health and the environment. With the increased popularity of biodiesel, there is a need to determine if these fuels produce different levels of particulate matter in exhaust emissions. This study examined the transient smoke emissions of three fuels: No. 2 petroleum diesel fuel (D2, ASTM D 975), a blend of 20% biodiesel and 80% petroleum diesel (B20, ASTM 6751), and a 100% pure biodiesel derived from animal fats (B100, ASTM D 6751). Measurements of smoke emissions were taken using the SAE J1677 snap acceleration test procedure on a John Deere 3203 compact …

Synthesis And Characterization Of Homoleptic And Heteroleptic Ruthenium Polypyridine Complexes, Anwar A. Bhuiyan, S. Kudo, C. Wade, R. F. Davis

Journal of the Arkansas Academy of Science

The homoleptic ruthenium(II) complex Ru(C13H10N2)3(PF6)2, and heteroleptic ruthenium(II) complexes Ru(C13H10N2)2(C10H8N2)(PF6)2, and Ru(C13H10N2)(C10H8N2)2(PF6)2 have been prepared by following the standard synthetic procedure. These complexes were then purified by repeated column chromatography. The identity and the integrity of the complexes were confirmed by elemental analysis and mass spectroscopy. The calculated and the experimental values for the elemental analysis were in good agreement. The calculated and the experimental molar masses obtained were also identical. Ultravioletvisible absorption and emission spectroscopic methods were used to investigate the properties of these complexes. The absorption spectra of all complexes consist of a series of absorption bands in …

Biological And Economic Considerations In Establishing A Short-Rotation Bioenergy Plantation, Jamie L. Schuler, M. Pelkki, Chris Stuhlinger

Journal of the Arkansas Academy of Science

The development of bio-fuel synthesis technologies has led to increased interest in woody crops grown specifically for energy production. These woody feedstocks typically involve fast-growing species (e.g., Salix spp., Populus spp.) planted at high densities using short rotations and intensive cultural practices like weed control and fertilization. Under ideal conditions, this type of system can produce 20 dry Mg/ha/yr, which is substantially higher than the 2.5-4 dry Mg/ha/yr produced by pine plantations in the southern U.S. Many of these plantings are projected to be established on lower quality agricultural lands. Recent attempts at establishing these plantations have highlighted some of …

Economic Impacts Of Future Biorefineries In The State Of Arkansas: An Input-Output Analysis, Sayeed R. Mehmood, M. H. Pelkki

Journal of the Arkansas Academy of Science

No abstract provided.

New Eclipsing Close Binary Star In The Constellation Of Sextants, Jeff W. Robertson

Journal of the Arkansas Academy of Science

No abstract provided.

Microwave Syntheses And Thermal Gravimetric Analysis Of Trans-Hydrogen Bis(Dimethylsulfoxide)Tetrachlororuthenate(Iii), S. Chui, Mark Draganjac, E. Benjamin, B. Rougaeu

Journal of the Arkansas Academy of Science

No abstract provided.