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University of Arkansas, Fayetteville

Journal

2004

Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Method Analysis Of Laboratory Measures Of Stream Sediment And Water Phosphorus Equilibrium, Anna L. Erickson, Stephanie M. Williamson, Brian E. Haggard Jan 2004

Method Analysis Of Laboratory Measures Of Stream Sediment And Water Phosphorus Equilibrium, Anna L. Erickson, Stephanie M. Williamson, Brian E. Haggard

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

Elevated phosphorus concentrations in aquatic ecosystems of northwest Arkansas prompted an investigation of the effects of sample preparation and extraction methods on laboratory measures of sediment-phosphorus interactions. Two streams of contrasting phosphorus (P) concentrations were selected to determine the effect of using a CaCl2 solution instead of filtered stream water, refrigerated or dried sediments instead of fresh wet sediments, and vortexing the suspensions instead of shaking them. Sediment equilibrium P concentration (EPC0) and P buffering capacity (K) were used to determine differences in extraction methods. EPC0 and K from extractions using fresh sediments and a CaCl2 solution matching the electrical …

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Assessment And Restoration Of A Neighborhood Wetland Invaded By Exotic Plant Species, Ryan Neal, Kimberly R. Payne, Lorena Moreno, Graham Duffy, Jonathan Peck, Mary C. Savin Jan 2004

Assessment And Restoration Of A Neighborhood Wetland Invaded By Exotic Plant Species, Ryan Neal, Kimberly R. Payne, Lorena Moreno, Graham Duffy, Jonathan Peck, Mary C. Savin

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

The University of Arkansas Crop, Soil, and Environmental Sciences (CSES) Club adopted a local wetland in the spring of 2002 through the Fayetteville Parks and Recreation Department. This project has allowed students to interact with local community and governmental organizations as well as other academic departments within the university. Students have gained valuable laboratory and field experience through characterizing hydric soils, identifying bird and plant species, and analyzing water quality, soil nutrients, and microbial biomass. Under the main goal of restoring the wetland, the club has outlined both short and long-term objectives including soil and water assessments; removal of two …

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Be Star Spectroscopy Using The Uca Fiber-Fed Spectrograph, Scott Austin Jan 2004

Be Star Spectroscopy Using The Uca Fiber-Fed Spectrograph, Scott Austin

Journal of the Arkansas Academy of Science

Beginning in June 2003, undergraduate students and the author have spectroscopically monitored bright Be stars using a custom built fiber-fed spectrograph attached to the UCA Observatory 11-inch Schmidt-Cassegrain telescope. We have obtained 0.8 Angstrom/pixel resolution spectra of the H-alpha line for over forty Be-Stars. Some have been observed on multiple dates in order to detect any temporal changes. Line profiles, velocities, and observed variations for some of these stars will be presented.

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Comparison Of Dissolved And Acid-Extractable Metal Concentrations In Groundwater, Eastern Arkansas, Burmshik Kim, Kenneth F. Steele, Todd Fugitt Jan 2004

Comparison Of Dissolved And Acid-Extractable Metal Concentrations In Groundwater, Eastern Arkansas, Burmshik Kim, Kenneth F. Steele, Todd Fugitt

Journal of the Arkansas Academy of Science

No abstract provided.

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Impact Of Black Shale Weathering On Sediment Quality, G. M. Ogendi, R. E. Hannigan, Jerry L. Farris, D. Smith Jan 2004

Impact Of Black Shale Weathering On Sediment Quality, G. M. Ogendi, R. E. Hannigan, Jerry L. Farris, D. Smith

Journal of the Arkansas Academy of Science

Weathering of black shales leads to elevated metal concentrations in both surface water and stream sediments. In spite of the recent focus on black shales, few data exist on the ecological impacts of this process particularly on aquatic organisms. The key objective of this study was to determine the impact of trace metal concentrations in sediments upon aquatic organisms. To achieve the above objective, stream sediment samples were collected from streams draining black shale and limestone (used as a reference stream) lithologies located in central Arkansas between June 2003 and January 2004. Trace metal concentrations were measured by the dynamic …

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Electric Discharge: Boundary Conditions, Mostafa Hemmati, Chris Justice Jan 2004

Electric Discharge: Boundary Conditions, Mostafa Hemmati, Chris Justice

Journal of the Arkansas Academy of Science

The electron gas in electric discharge can be described by a set of one-dimensional fluid dynamical equations. The fundamental equations are those of a three-component (electrons, ions, and neutral particles) fluid, different from the treatment of the problem inplasma physics, a fully ionized two-component case. The leading edge of the wave is treated as a shock front driven mainly by the electron gas pressure. Integrating the one-dimensional global differential equations for mass balance, conservation of momentum and energy, and evaluating the constant of integration at the wave front permits derivation of boundary conditions on electron temperature and electron velocity. Using …

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Laboratory-Scale Evaluation Of Incandescent And Compact Florescent Lamps For Poultry House Lighting, Leanne Gabriel, Donald M. Johnson Jan 2004

Laboratory-Scale Evaluation Of Incandescent And Compact Florescent Lamps For Poultry House Lighting, Leanne Gabriel, Donald M. Johnson

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

This laboratory-scale study compared 1000- and 2000-h rated 60W incandescent lamps and 6000-h rated 60W-equivalent compact florescent lamps over 6000 h of simulated broiler-house operation. The four original 1000-h incandescent lamps were replaced 22 times and the four 2000-h incandescent lamps were replaced 14 times. None of the four compact florescent lamps failed during the 6000-h experiment, although one was broken due to human error. Both types of incandescent lamps had significantly higher (p < .0001) mean illuminance (lx) than did the compact florescent lamps. The compact florescent lamps used significantly less (p < .0001) power (W) and had significantly higher (p < .0001) efficiency (lx/W) than the incandescent lamps. Despite a higher initial purchase price, the total cost (purchase + replacement + electrical) of operating compact florescent lamps was approximately 36% lower than the total cost of operating either type of incandescent lamp over the 6000 h period. The results of this study indicate that even at a least-cost price for electricity ($0.04/kW/h), growers can reduce total broilerhouse lighting costs by replacing incandescent lamps with compact florescent lamps.

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Characterizing Bean Pod Rot In Arkansas And Missouri, Jeremy H. Taylor, Craig S. Rothrock Jan 2004

Characterizing Bean Pod Rot In Arkansas And Missouri, Jeremy H. Taylor, Craig S. Rothrock

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

Green beans are an important crop grown for processing in both Arkansas and Missouri. Green beans are harvested mechanically using non-selective picking fingers. Harvested beans are then transported in bulk to processing plants that are located at various locations throughout the midSouth. Thus, the crop is managed for high quality, avoiding pod blemishes caused by insects and diseases. One of the consistent quality problems that affect Arkansas and Missouri green bean crops is pod rot. Two of the causal agents of pod rot that have been reported by researchers and vegetable companies alike are Pythium aphanidermatum and an unidentified Phytophthora …

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Effects Of Vegetation Removal On Native Soil Quality In Eastern Arkansas, Lorena Moreno, Kristofor R. Brye Jan 2004

Effects Of Vegetation Removal On Native Soil Quality In Eastern Arkansas, Lorena Moreno, Kristofor R. Brye

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

Aboveground vegetation removal practices, such as cutting and baling and burning, can both positively and negatively affect a prairie ecosystem. Burning can stimulate growth and species diversity, but removing vegetation and the nutrients it contains without equal replenishment of those nutrients could cause a steady decline in available soil nutrients. The objective of this study was to evaluate the effects of vegetation removal techniques in a native tallgrass prairie in eastcentral Arkansas. Soil samples were collected from the top 10 cm in each soil mapping unit that existed in each of three prairie areas that differed by the amount of …

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The Effects Of Multiple Mutations In The Hydrophobic Core Upon The Stability Of Staphylococcal Nuclease, Rebecca L. Danforth Jan 2004

The Effects Of Multiple Mutations In The Hydrophobic Core Upon The Stability Of Staphylococcal Nuclease, Rebecca L. Danforth

Inquiry: The University of Arkansas Undergraduate Research Journal

Previous work in the laboratory of my research advisor, Dr. Wesley Stites, has investigated the core packing of the protein staphylococcal nuclease. The core of a protein is critical in determining a protein's structure and stability. The hydrophobicity of the core has long been thought to be the principal driving force for folding, but recent work in the Stites lab has shown that optimization of van der Waals contacts and minimization of cavities, in our shorthand term, packing, is at least as energetically important. We are building upon this information in our attempt to better pack the protein core. If …

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Tailwater Recovery Systems For Irrigation: Benefit/Cost Analysis And Water Resource Conservation Technique In Northeast Arkansas, Jennifer L. Bouldin, Nate A. Bickford, H. B. Stroud, G. S. Guha Jan 2004

Tailwater Recovery Systems For Irrigation: Benefit/Cost Analysis And Water Resource Conservation Technique In Northeast Arkansas, Jennifer L. Bouldin, Nate A. Bickford, H. B. Stroud, G. S. Guha

Journal of the Arkansas Academy of Science

Water, one of the earth's most vital resources, is particularly significant in the Arkansas Delta agricultural landscape. While both surface and groundwater are extremely important, 94% of the 26.9 billion L (7.1 billion gal) of water pumped daily from the Alluvial Aquifer is used for agricultural purposes. This common property is subsequently being depleted and sustainable conservation methods are being pursued. State and federal incentive programs encourage the use of a tailwater recovery system in agricultural irrigation. With the use of a complete recovery system, benefits include not only government incentives for wetland habitat, but reduced groundwater use and decreased …

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