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University of Arkansas, Fayetteville

2003

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Articles 1 - 27 of 27

Full-Text Articles in Physical Sciences and Mathematics

Swine Waste Demonstration And Training Project, C. V. Maxwell, K. Vandevender, K. P. Coffey, P. A. Moore, I. Chaubey, D. R. Smith Dec 2003

Swine Waste Demonstration And Training Project, C. V. Maxwell, K. Vandevender, K. P. Coffey, P. A. Moore, I. Chaubey, D. R. Smith

Technical Reports

No abstract provided.

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Water Quality Monitoring Of Moore's Creek Above Lincoln Lake, M. A. Nelson, L. W. Cash, G. K. Trost Nov 2003

Water Quality Monitoring Of Moore's Creek Above Lincoln Lake, M. A. Nelson, L. W. Cash, G. K. Trost

Technical Reports

No abstract provided.

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Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Wyman Road Bridge On The White River, Marc Nelson, Wade Cash Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Wyman Road Bridge On The White River, Marc Nelson, Wade Cash

Technical Reports

A water quality sampling station was installed at the Wyman Road Bridge just below the confluence of the three main forks of the Upper White River in January 2000. This station is coordinated with the USGS gaging station at the same location. This station was instrumented to collect samples at sufficient intervals across the hydrograph to accurately estimate the flux of total suspended solids, nitrogen and phosphorus into the upper end of Beaver Lake from the Upper White River.

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2002 Pollutant Loads Kings River Near Berryville, Arkansas, Marc Nelson, Wade Cash Nov 2003

2002 Pollutant Loads Kings River Near Berryville, Arkansas, Marc Nelson, Wade Cash

Technical Reports

An automatic sampler and a USGS gauging station were established in 1998 and water quality sampling was begun in 1999 on the Kings River near Berryville, Arkansas. Continuous stage and discharge measurements and frequent water quality sampling have been used to determine pollutant concentrations and loads in the river. This report presents the results from the sampling and analysis for January 1, 2002 to December 31, 2002.

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Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River, Marc Nelson, Wade Cash Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River, Marc Nelson, Wade Cash

Technical Reports

A water quality sampling station was installed at the Washington County Road 195 Bridge on the West Fork of the White River just above the confluence of the three main forks of the Upper White River in December 2001. The Quality Assurance Project Plan (QAPP) was approved by EPA Region Six on March 2002 and sampling was begun at that time. This station is coordinated with a USGS gauging station at the same location. This station was instrumented to collect samples at sufficient intervals across the hydrograph to accurately estimate the flux of total suspended solids, nitrogen and phosphorus into …

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Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 76 Bridge On Ballard Creek, Marc A. Nelson, Ron Redman, L. Wade Cash, G. Keith Trost Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 76 Bridge On Ballard Creek, Marc A. Nelson, Ron Redman, L. Wade Cash, G. Keith Trost

Technical Reports

The Illinois River Basin has experienced water quality impairment from non-point source pollution for many years. This fact was well documented in the State of Arkansas' Water Quality Assessment report, the Soil Conservation Service River Basin Study, and several University of Arkansas, Fayetteville studies. Thirty-seven sub-watersheds have been identified by the SCS in the Arkansas portion of the Illinois River basin. In the Arkansas portion of the Basin, the Illinois River, Evansville Creek, Baron Fork, Cincinnati Creek, Muddy Fork, Moores Creek, Clear Creek, Osage Creek and Flint Creek were all classified as not supporting their designated use as primary contact …

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Illinois River 2002 Pollutant Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, Wade Cash Sep 2003

Illinois River 2002 Pollutant Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, Wade Cash

Technical Reports

Automatic water samplers and a U. S. Geological Survey gauging station were established in 1995 on the main stem of the Illinois River at the Arkansas Highway 59 Bridge. Since that time, continuous stage and discharge measurements and water quality sampling have been used to determine pollutant concentrations and loads in the Arkansas portion of the Illinois River. This report represents the results from the measurement and sampling by the Arkansas Water Resources Center -Water Quality Lab for January 1, 2002 to December 31, 2002.

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Stormwater Pollution Prevention Bmp Workshop, Demonstration, And Evaluation, Findlay G. Edwards Jun 2003

Stormwater Pollution Prevention Bmp Workshop, Demonstration, And Evaluation, Findlay G. Edwards

Technical Reports

With the recent promulgation of Phase II of the National Pollution Discharge Elimination System (NPDES) Stormwater Pollution Control regulations, many construction companies, consulting engineers, architects, and regulating agency personnel are unaware of the new stormwater pollution reduction requirements. In addition, they are typically unaware of Best Management Practices (BMPs) that are available to mitigate stormwater discharge pollution and the proper methods of installing and maintaining BMPs. The Water Quality Goals and Objectives were to train engineers, contractors, architects, and governmental officials on the new Phase II Storm Water NPDES regulations and Best Management Practices available for construction projects. The Original …

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Bioassessment Of The West Fork Of The White River, Northwest Arkansas, Arthur V. Brown, Andrea J. Radwell, Robin A. Reese Jun 2003

Bioassessment Of The West Fork Of The White River, Northwest Arkansas, Arthur V. Brown, Andrea J. Radwell, Robin A. Reese

Technical Reports

The West Fork-White River has been and continues to be an important water resource for northwest Arkansas. It is used recreationally for fishing and swimming, agriculturally as a source of water for livestock and irrigation of crops, it is mined for gravel, used as a receiving stream for municipal wastewater effluent, and contributes to Beaver Lake which provides water for treatment and distribution to most of northwest Arkansas. While these uses have benefited a large segment of the Arkansas population, they have also contributed to the decline in environmental quality of the river. To facilitate the development of appropriate management …

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Wayne E. Sabbe Arkansas Soil Fertility Studies 2002, Nathan A. Slaton Mar 2003

Wayne E. Sabbe Arkansas Soil Fertility Studies 2002, 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 contained within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

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Watershed-Scale Agricultural Land-Use Impact On Instream Physicochemical Parameters, William Dillahunty, Indrajeet Chaubey, Marty Matlock Jan 2003

Watershed-Scale Agricultural Land-Use Impact On Instream Physicochemical Parameters, William Dillahunty, Indrajeet Chaubey, Marty Matlock

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

Nonpoint source (NPS) pollution is often the result of runoff losses from agricultural or urban areas. Even though the watershed approach to controlling NPS pollution is identified as the most efficient approach, data linking watershed scale land use and specific water quality implications are very limited. The objective of this study was to quantify the impact of agricultural land use on stream physico-chemical properties. The upper reach of Flint Creek was monitored at two sampling points draining an agricultural land. At each of these points, continuous measurement of stream characteristics such as temperature, dissolved oxygen (DO) concentration, depth, pH, and …

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Computer Modeling Of Tornado Forces On A Cubic Building Using Large Eddy Simulation, R. Panneer Selvam, Paul C. Millett Jan 2003

Computer Modeling Of Tornado Forces On A Cubic Building Using Large Eddy Simulation, R. Panneer Selvam, Paul C. Millett

Journal of the Arkansas Academy of Science

A tornado changes its wind speed and direction rapidly; therefore, it is difficult to study the effects of a tornado on buildings in a wind tunnel. The status of the tornado-structure interaction and various models of the tornado wind field found in literature are surveyed. Three dimensional computer modeling work using the turbulence model based on large eddy simulation is presented. The effect of a tornado on a cubic building is considered for this study. The Navier-Stokes (NS) equations are approximated by the finite difference method and solved by an implicit procedure. The force coefficients are plotted in time to …

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Evaluation Of Sampling Strategies On Load Estimation For Illinois River At Highway 59, T. S. Soerens, M. A. Nelson Jan 2003

Evaluation Of Sampling Strategies On Load Estimation For Illinois River At Highway 59, T. S. Soerens, M. A. Nelson

Technical Reports

This study investigated the precision and accuracy of the two load calculation techniques. The study compared total phosphorus loads calculated by integration of Arkansas Water Resources Center (AWRC) intensive sampling data to loads calculated by a regression technique (rating curve) using fewer data. The 1998 AWRC dataset from the Illinois River at Arkansas Highway 59 was sub-sampled in a manner to simulate fixed period monitoring schemes supplemented with storm sampling. The ESTIMATOR software program was used to calculate loads. These loads were compared to the integrated load. The error of the integrated load when the variation in concentration between samples …

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Thesis Digest: Mathematical Interpretation Of Political Power And The Arkansas State Government, Andrew King Jan 2003

Thesis Digest: Mathematical Interpretation Of Political Power And The Arkansas State Government, Andrew King

Inquiry: The University of Arkansas Undergraduate Research Journal

On the whole, political power can he very difficult to quantify. A person may be powerful due to his or her personal charm, wealth, fame, credibility, or influential connections. Political bodies do not account for these qualities when creating voting procedures; they only assign voting rules to specific positions. For example, most would say that in the United States government that a Senator is more powerful than a Representative, but less powerful than the President, without knowing any way to quantify or verify those differences. Since the 1950's, mathematicians and political scientists have attempted to create mathematical models that partially …

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Study Of Nanoidentation And Tip Geometry In Gaas (100) At Ultra-Low-Loads For The Patterning Of Quantum Dots, Robin Prince Jan 2003

Study Of Nanoidentation And Tip Geometry In Gaas (100) At Ultra-Low-Loads For The Patterning Of Quantum Dots, Robin Prince

Inquiry: The University of Arkansas Undergraduate Research Journal

In this study, nanoindentations were produced and characterized for the future patterning of quantum dots. Nanoindentation was performed on a Si-doped (n-type) Vertical Gradient Freeze (VGF) GaAs (100) wafer with a 700 nm GaAs (100) layer grown by molecular beam epitaxy (MBE). Nanoindentation was performed with a Berkovich diamond tip, a cube corner diamond tip, and a 600 conical diamond tip. Nanoindentation of GaAs has been studied in the past, but not at extremely low loads. Previous research has been done on high load (50-200 mN) and low load (200-8000 mN) nanoindentation. The applied load in this study ranges from …

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Multiphoton Interaction In A System Of Two Quantum Dots, Brian Sawyer Jan 2003

Multiphoton Interaction In A System Of Two Quantum Dots, Brian Sawyer

Inquiry: The University of Arkansas Undergraduate Research Journal

As the size and proximity of components on modern computer chips approaches quantum mechanical limits, various novel solutions have been proposed to ensure further increases in processing speed and reliability. Of these, small semiconductor devices called quantum dots may constitute the logic gates of future quantum computers - processors taking advantage of phenomena such as entanglement and quantum teleportation to enable ultra-fast computation speeds. Quantum dots behave much like designer atoms in that their absorption/emission energies can be adjusted lo desired values. A quantum mechanical model of semiconductor quantum dots having equal size and interacting with a single-mode electric field …

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On The Existence And Stability Of Liquid Water On The Martian Surface, Justin Thompson Jan 2003

On The Existence And Stability Of Liquid Water On The Martian Surface, Justin Thompson

Inquiry: The University of Arkansas Undergraduate Research Journal

Present-day Mars is thought to be a frozen desert on which liquid water is not likely to be found. The prevailing assumption has been that due to average temperatures below 273 K and atmospheric pressures at or below water's triple-point vapor pressure of 6.1 mbar, the existence of liquid water as an equilibrium phase at or near the surface is impossible at the present epoch. However, there is substantial evidence that liquid water has existed in the past and may presently still exist on or directly below the Martian surface. I conducted simulation experiments in the Andromeda planetary environmental chamber …

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Soil Particle-Size Analysis: A Comparison Of Two Methods, Lauren Williams-Caudle, Kristofor Brye, E. Moye Rutledge Jan 2003

Soil Particle-Size Analysis: A Comparison Of Two Methods, Lauren Williams-Caudle, Kristofor Brye, E. Moye Rutledge

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

Knowing the proportion of particle sizes in soil is important to soil scientists and agronomists. The mixture of sand, silt, and clay influences water movement, solute transport, nutrient retention, and many other properties and processes in soil. The standard method for particle size determination is a somewhat time-consuming process. An equally accurate but shorter method would be appealing for many reasons. The objective of this study was to compare a standard method of particle-size analysis using a hydrometer to an abbreviated hydrometer method, which, instead of 12 h for the standard method, requires about 3 h to complete. Twenty-four soil …

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Pid Stabilization Of A Position-Controlled Robot Manipulator Acting Independently Of In Collaboration With Human Arm, Anindo Roy, Kamran Iqbal Jan 2003

Pid Stabilization Of A Position-Controlled Robot Manipulator Acting Independently Of In Collaboration With Human Arm, Anindo Roy, Kamran Iqbal

Journal of the Arkansas Academy of Science

In this paper we develop framework for PID stabilization of a robot manipulator when using an object independently or in collaboration with a human arm. In both applications, the manipulator is equipped with a wrist sensor represented by an impedance. A second order manipulator transfer function along each coordinate direction is assumed. The aim of the paper is to design a PID controller when measurement of contact force, available via wrist sensor, is used to command the position controlled manipulator to a desired position and/or force profile. Necessary and sufficient conditions for stability of the closed loop system are developed …

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Fishes Of The Red River In Arkansas, Thomas M. Buchanan, Drew Wilson, L. G. Claybrook, William G. Layher Jan 2003

Fishes Of The Red River In Arkansas, Thomas M. Buchanan, Drew Wilson, L. G. Claybrook, William G. Layher

Journal of the Arkansas Academy of Science

Fishes were collected from Red River mainstem habitats in Arkansas with seines, rotenone, hoop nets, gill nets, and trotlines from 1995 through 2001. Seventy-two species were identified distributed among 17 families, and 15 species were new records for the Red River in Arkansas. Eighty-three species are now historically known from the Arkansas segment of the Red River. Approximately 67% of the fishes known from the entire Red River have been found in the Arkansas segment, which is only 11% of the entire river length. Baseline data on the fish fauna of the Red River is critical for the analysis of …

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Antiforce Wave Profile For Quasi-Neutral Region, Mostafa Hemmati, Pashupati Adhikari, Jeremy Eckart, Marcus Ilbara Jan 2003

Antiforce Wave Profile For Quasi-Neutral Region, Mostafa Hemmati, Pashupati Adhikari, Jeremy Eckart, Marcus Ilbara

Journal of the Arkansas Academy of Science

This article will present a fluid dynamical theory for breakdown waves in which the direction of electric field force on electrons is in the opposite direction of wave propagation. We will refer to such waves as antiforce waves. The set of equations describing the model will include the equation of particle mass balance, equation of conservation of momentum, and equation of conservation of energy, coupled with Poisson's equation. This model treats the potential wave front as an electron shock wave propagating forward mainly due to the electron impact ionization. The shock front is succeeded by a thin dynamical transition region …

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Winter And Spring Water Quality Of The Big Creek Watershed, Craighead County, Arkansas: Nutrients, Habitat, And Macroinvertebrates, Alan D. Christian, Jennifer L. Bouldin, Nate A. Bickford, Samuel B. Mccord, Aboubakar Sako, Jerry L. Farris, Lynn Kanieski, Ashley Mcbride Jan 2003

Winter And Spring Water Quality Of The Big Creek Watershed, Craighead County, Arkansas: Nutrients, Habitat, And Macroinvertebrates, Alan D. Christian, Jennifer L. Bouldin, Nate A. Bickford, Samuel B. Mccord, Aboubakar Sako, Jerry L. Farris, Lynn Kanieski, Ashley Mcbride

Journal of the Arkansas Academy of Science

The objective of this study was to assess the water quality of the Big Creek watershed during the winter and spring of 2002 by analyzing water physical, chemical variables, aquatic macro-invertebrates, and habitat. The Big Creek watershed, arising on Crowley's Ridge in northeast Arkansas, is a small deltaic watershed and is an area of intense cultivation. Four stations, Big Creek Upper (BCU), Mud Creek (MC),Lost Creek (LC), and Big Creek Lower (BCL) were established for this study from Big Creek, Mud Creek and Lost Creek. Water samples were collected on a weekly basis for 10 weeks from January 2002 through …

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Fenske-Hall Approximate Molecular Orbital Analysis Of The Chelating Carbene Complex Eta5-Cp'(Co)Mn{C(Oet)Ch2pph2}, John P. Graham Jan 2003

Fenske-Hall Approximate Molecular Orbital Analysis Of The Chelating Carbene Complex Eta5-Cp'(Co)Mn{C(Oet)Ch2pph2}, John P. Graham

Journal of the Arkansas Academy of Science

The novel three legged piano stool chelating carbene complex, Cp'(CO)Mn{C(OEt)CH2PPh2}, 1, exhibits interesting structural, spectroscopic and electrochemical properties. It also readily undergoes reaction with CO to produce the three legged piano stool complex Cp'(CO)2{PPh2C(OEt)=CH2}, 2. This is in contrast to the analogous non-chelating complex Cp(CO)(PPh3)Mn{C(OMe)CH2CH3}, 3, which does not react with CO. This paper discusses the results of Fenske-Hall approximate molecular orbital calculations on model complexes for 1 and 3. The differences in spectroscopic and electrochemical properties are explained using molecular orbital analysis. Possible reasons for the enhanced reactivity of 1are also presented.

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Identifying Minimum G Aberration Designs For Hadamard Matrices Of Order 28, Steffany Belcher-Novosad, Debra Ingram Jan 2003

Identifying Minimum G Aberration Designs For Hadamard Matrices Of Order 28, Steffany Belcher-Novosad, Debra Ingram

Journal of the Arkansas Academy of Science

No abstract provided.

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Acoustic Mapping Of Aquatic Vegetation In Lakes: An Example From Northwest Arkansas, Angela M. Polly, Stephen K. Boss Jan 2003

Acoustic Mapping Of Aquatic Vegetation In Lakes: An Example From Northwest Arkansas, Angela M. Polly, Stephen K. Boss

Journal of the Arkansas Academy of Science

No abstract provided.

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Stabilization Of Polyvinyl Chloride By Some Conducting Polymers, Amit Shah, Brian C. Berry, Ali U. Shaikh Jan 2003

Stabilization Of Polyvinyl Chloride By Some Conducting Polymers, Amit Shah, Brian C. Berry, Ali U. Shaikh

Journal of the Arkansas Academy of Science

No abstract provided.

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Interpolation Techniques For Overset Grids, Paul S. Sherman, Nathan B. Edgar Jan 2003

Interpolation Techniques For Overset Grids, Paul S. Sherman, Nathan B. Edgar

Journal of the Arkansas Academy of Science

The use of finite difference schemes in computational aeroacoustics requires the use of structured grids incomputational space. Complex geometries in the physical space can be modeled using multiple overlapping grids that are transformed into computational space. In this work, finite difference schemes are used that necessitate the addition of psuedo- or ghost-points in the overlap region of the grids for closure of the difference stencil. The functional values at these ghost points must be approximated from the values at the original grid points. This paper investigates interpolation techniques for these overset grids. An n th order interpolation scheme using Lagrange …

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