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University of Arkansas, Fayetteville

1994

Articles 1 - 23 of 23

Full-Text Articles in Physical Sciences and Mathematics

Determination Of The Seasonal Changes In Nitrate And Phosphate Concentration And Phytoplankton Composition Within Selected Fertilized Lakes, Richard L. Meyer Dec 1994

Determination Of The Seasonal Changes In Nitrate And Phosphate Concentration And Phytoplankton Composition Within Selected Fertilized Lakes, Richard L. Meyer

Technical Reports

No abstract provided.

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The Moore's Creek Monitoring Project, D. R. Edwards, T, C, Daniel, J. F. Murdoch, P. F. Vendrell, D. J. Nichols Oct 1994

The Moore's Creek Monitoring Project, D. R. Edwards, T, C, Daniel, J. F. Murdoch, P. F. Vendrell, D. J. Nichols

Technical Reports

No abstract provided.

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Phosphorus Immobilization In Poultry Litter And Litter-Amended Soils With Aluminum, Calcium And Iron Amendments, D. M. Miller, P. A. Moore Jr., T. C. Daniels Sep 1994

Phosphorus Immobilization In Poultry Litter And Litter-Amended Soils With Aluminum, Calcium And Iron Amendments, D. M. Miller, P. A. Moore Jr., T. C. Daniels

Technical Reports

Arkansas produces approximately one billion broilers each year. Phosphorous (P) runoff from fields receiving poultry litter is believed to be one of the primary factors affecting water quality in Northwest Arkansas. Poultry litter contains approximately 20 g P kg-1, of which about 2 g P kg-1 is water soluble. Soils that have received repeated heavy applications of litter may have water soluble P contents of as high as 10 mg P Kg-1 soil. The objective of this study was to determine if soluble P levels could be reduced in poultry litter and litter-amended soils with Al,Ca, and/or Fe amendments. Poultry …

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Correlating Soil Test Phosphorus Losses In Runoff, D. H. Pote, T. C. Daniel, P. A. Moore Jr., D. J. Nichols, D. R. Edwards, A. N. Sharpley Jun 1994

Correlating Soil Test Phosphorus Losses In Runoff, D. H. Pote, T. C. Daniel, P. A. Moore Jr., D. J. Nichols, D. R. Edwards, A. N. Sharpley

Technical Reports

Phosphorus in agricultural runoff is often a major cause of accelerated eutrophication of lakes and streams. Previous research has indicated that the amount of dissolved P (DP) in runoff is directly related to P content of the surface soil. Decades of fertilizer application at rates exceeding those of crop uptake have elevated soil test P (STP) levels in areas of intensive crop and livestock production, making this the major source of DP loss in runoff. The objective of our experiment was to relate STP content of Captina silt loam to P concentration and loss in runoff, and determine which STP …

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Assessment Of Effectiveness Of Buffer Zones In Removing Impurites In Runoff From Areas Treated With Poultry Litter, I. Chaubey, D. R. Edwards, T. C. Daniels Jun 1994

Assessment Of Effectiveness Of Buffer Zones In Removing Impurites In Runoff From Areas Treated With Poultry Litter, I. Chaubey, D. R. Edwards, T. C. Daniels

Technical Reports

Land application of animal manures (e.g. poultry litter, poultry manure, and swine manure) to pasture and range can lead to runoff quality degradation during storms that occur soon after application. Vegetative filter strips (VFS) have been shown to reduce pollution in runoff from row-cropped areas but have not been extensively studied in pasture and range settings. This research involved characterizing performance of fescue VFS in improving quality of runoff from pasture land areas treated with poultry litter and swine manure. The VFS were found to be quite effective in reducing off-site transport of ammonia nitrogen (NH3-N), total Kjeldahl nitrogen (TKN), …

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The Prediction Of Sediment And Nutrient Transport In The Buffalo River Watershed Using A Geographic Information System, H. D. Scott, P. A. Smith Jun 1994

The Prediction Of Sediment And Nutrient Transport In The Buffalo River Watershed Using A Geographic Information System, H. D. Scott, P. A. Smith

Technical Reports

The Buffalo River was established by Congress in 1972 as the first National River in the United States. It is one of the few remaining free-flowing streams in northern Arkansas. The river originates in the higher elevations of the Boston Mountains in Newton County, and generally flows northeastward, intersecting the Springfield and Salem Plateaus as it drops from approximately 2000 feet in the headwaters to around 500 feet at the confluence with the White River in Marion County. It is considered by many to be one of Arkansas' greatest natural treasures, and therefore , there is strong interest in protecting …

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Arkansas Rice Research Studies 1993, B. R. Wells Jun 1994

Arkansas Rice Research Studies 1993, B. R. Wells

Arkansas Agricultural Experiment Station Research Series

The research reports in this publication represent one year of results; therefore, these results should not be used as a basis for longterm recommendations. Several research reports in this publication dealing with soU fertility also appear in Arkansas Soil Fertility Studies 1993, Arkansas Agricultural Experiment Station Research Series 436. This duplication is the result of the overlap in research coverage between the two series and our effort to inform Arkansas rice producers of all the research being conducted with funds from the rice check-off.

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Boron Phosphate And Aluminum Phosphate Aerogels, David A. Lindquist, Steven M. Poindexter, Sterling S. Rooke, D. Ritchie Stockdale, Kirk B. Babb, Alison L. Smoot, William E. Young Jan 1994

Boron Phosphate And Aluminum Phosphate Aerogels, David A. Lindquist, Steven M. Poindexter, Sterling S. Rooke, D. Ritchie Stockdale, Kirk B. Babb, Alison L. Smoot, William E. Young

Journal of the Arkansas Academy of Science

Anhydrous sol-gel condensation of triethyl phosphate [(CH3CH2O)3PO] with boron trichloride (BCL3 ) or triethyl aluminum [(CH3CH2 ) 3A1] in organic solvents, led to formation of metallophosphate gels. The pore fluid of the gels was removed under supercritical conditions in a pressurized vessel to form aerogels. The aerogels were then calcined at progressively higher temperatures to produce high surface area phosphates. Since the initial gel reagent mixtures contained several NMR active nuclei, the condensation chemistry prior to the gel point was monitored by solution nB NMR. The surface areas, distribution of pore sizes, and total pore volumes of the aerogel products …

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Ground Water Monitoring Project For Arkansas, Phase Iii, Kenneth F. Steele, Steven S. Hill, Terry W. Nichols, H. Don Scott, Paul Vendrell, H. S. Lin Jan 1994

Ground Water Monitoring Project For Arkansas, Phase Iii, Kenneth F. Steele, Steven S. Hill, Terry W. Nichols, H. Don Scott, Paul Vendrell, H. S. Lin

Technical Reports

This report is composed of two parts. The first part is an interpretation of the pesticide and nitrate data collected in Woodruff County based on samples collected during 1994. Because there is an indication that there were hydrological differences between 1994 and 1995, and because most of the pesticide data is from 1994, this interpretive portion is restricted to 1994 data. Six wells initially sampled in 1994 that contained pesticides had continuing contamination in re-sampling in 1994 and 1995. Part II lists a seventh well in Woodruff County that contained pesticides in February and May of 1995

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Hammett Correlations Of Half-Wave Reduction Potentials In A Series Of N-(Aryl Substituted)-Dichloronicotinamides, Cecil C. Persons, Ali U. Shaikh, Julie Shiflett, Frank L. Setliff Jan 1994

Hammett Correlations Of Half-Wave Reduction Potentials In A Series Of N-(Aryl Substituted)-Dichloronicotinamides, Cecil C. Persons, Ali U. Shaikh, Julie Shiflett, Frank L. Setliff

Journal of the Arkansas Academy of Science

Excellent correlations of Hammett substituent constants (sigmaR) of a series of N-(R-substituted aryl) -2,6-, 2,5-, and 5,6- dichloronicotinamides with polarographic half-wave potentials were observed. Although the correlations demonstrate that all three series of amides experience comparable sensitivity to the R groups at the carbonyl reduction site, the relative ease of reduction varies according to the chlorine substitution pattern on the pyridine ring. These differences are suggested to be due to combinations of mesomeric, inductive, and field effects which operate differently in the three systems. Correlation analysis also revealed that Hammett heteroatomic replacement constants previously determined by NMR studies are valid …

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Storm Dominated Channel Sequences On A Shallow Marine Shelf: Morrowan Of Northwest Arkansas, Kimberley R. Jones, Doy L. Zachry Jan 1994

Storm Dominated Channel Sequences On A Shallow Marine Shelf: Morrowan Of Northwest Arkansas, Kimberley R. Jones, Doy L. Zachry

Journal of the Arkansas Academy of Science

The Brentwood Member of the Bloyd Formation (Morrowan, Pennsylvanian) in northwestern Arkansas contains stratigraphic sequences deposted by tropical storms in middle shelf environments. The deposits are confined to shallow channels incised by strong unidirectional currents into an interval of shale deposited during fair weather conditions. Complete storm sequences reflect initial bottom currents of high competency that declined through time and were succeeded by wave generated oscillatory activity. The storm succession consists of an erosion surface followed by a basal pebble conglomerate, massive grainstone and packstone, whole-fossil wackestone, hummocky cross-strata and a swell lag of platy crinoidcalyxes. As storm activity ceased, …

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Computational Fluid Dynamics In Small Airway Models Of The Human Lung, G. Burnside, J. R. Hammersley, Rama N. Reddy, B. Catlin Jan 1994

Computational Fluid Dynamics In Small Airway Models Of The Human Lung, G. Burnside, J. R. Hammersley, Rama N. Reddy, B. Catlin

Journal of the Arkansas Academy of Science

The promise of gene replacement therapy for cystic fibrosis, the administration of drugs via inhalation therapy, and die deposition location of man-made airborne particulates all involve a more complete understanding of the fluid dynamics in the human lung. Flow in the larger airways may be measured through life-sized models directly, but the airways in the peripheral lung are too small and the flows are too complex to be studied in this manner. Computational models can be developed which will accurately represent both the geometric nature of the central airways and the fluid dynamics with in them. Two-dimensional and three-dimensional models …

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Visualizing Electrostatic Phenomena Using Mathematica, Eric Mayes Jan 1994

Visualizing Electrostatic Phenomena Using Mathematica, Eric Mayes

Journal of the Arkansas Academy of Science

A set of packages for visualizing electrostatic phenomena was developed using Mathematica as a programming language. These packages allow users to plot potential fields, equipotential lines, 2-D and 3-D vector fields in order to gain a visual understanding of electrostatic charges. They would be useful in accompanying undergraduate physics labs pertaining to electrostatics, as they would enable students to connect experiment with mathematics through open-ended visual exploration

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Aquatic Macrophytes Of Two Small Northwest Arkansas Reservoirs, John J. Sullivan, Arthur V. Brown Jan 1994

Aquatic Macrophytes Of Two Small Northwest Arkansas Reservoirs, John J. Sullivan, Arthur V. Brown

Journal of the Arkansas Academy of Science

Lake Fayetteville and Lake Wedington are small reservoirs of about the same size and age that are located in northwestern Arkansas. We collected macrophytes from eleven transects around each reservoir in the autumn of 1993. Justicia (waterwillow), Typha (cat-tail), Scirpus (bulrush), Potamogeton (pondweed), and Zannichellia (horned pondweed) occur in both reservoirs. Justicia occurs most commonly in both reservoirs. The macrophytes of Lake Wedington are organized in a characteristic zonation pattern with bands from shore toward open water of emergent, floating-leaved, then submersed macrophytes. Macrophyte zonation was not as evident in Lake Fayetteville because of the low occurrence of floating leaved …

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Monte Carlo Simulation Of The Scintillating Optical Fiber Calorimeter (Sofcal), Zibin Yang, Russell Gillum, Donald C. Wold Jan 1994

Monte Carlo Simulation Of The Scintillating Optical Fiber Calorimeter (Sofcal), Zibin Yang, Russell Gillum, Donald C. Wold

Journal of the Arkansas Academy of Science

A scintillating optical fiber calorimeter (SOFCAL) is being developed by NASA/Marshall Space Flight Center for use in balloon-borne emulsion chambers to study the spectrum of high-energy cosmic rays and gamma rays. SOFCAL will not saturate for long exposures, and the detector will be helpful for the study of primary cosmic-ray nuclei energies from 100 GeV to 1,000 TeV. For a given incident particle and energy, computer simulations of electromagnetic cascades allow computation of energy deposited in different regions of the calorimeter. For these initial simulations, a 5-cm x 5-cm x 7-cm calorimeter was used. Each subsection contained a 0.4-cm thick …

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Using The Cern Program-Library Graphics And Interactive Data Display, Morgan T. Burks, Wilson H. Howe, Christine A. Byrd, Wilfred J. Braithwaite Jan 1994

Using The Cern Program-Library Graphics And Interactive Data Display, Morgan T. Burks, Wilson H. Howe, Christine A. Byrd, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

Small scale Monte Carlo programming is growing rapidly due to the ease with which complex problems may be formulated by any programmer. These programmers may choose to exploit graphics and interactive displays available in the program library developed and maintained by CERN (the Center for European Nuclear Research). This paper outlines the use of graphics and interactive data display features of the CERN program library, developed for visualizing simulated data events in particle detectors. One example uses GEANT, CERN's Monte Carlo modeling program, to simulate 300 MeV/c protons incident on a silicon slab. Display packages for GEANT are available both …

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Reaction Of Titanocene Dichloride With Acetylenedicarboxylate, Tanya L. Hagler, Mark Draganjac, Paul M. Nave, J. Ed Bennett, Farooq Kahn, Robert Engelken, Gerard Williams, Chris Poole, Kwok Fai Yu Jan 1994

Reaction Of Titanocene Dichloride With Acetylenedicarboxylate, Tanya L. Hagler, Mark Draganjac, Paul M. Nave, J. Ed Bennett, Farooq Kahn, Robert Engelken, Gerard Williams, Chris Poole, Kwok Fai Yu

Journal of the Arkansas Academy of Science

The reaction of Cp2TiCl2 with either the mono- or dipotassium salt of acetylenedicarboxylic acid (ADC) gives high yields of an insoluble orange product. The insoluble compound shows potential semiconductor behavior, as evidenced by an apparent bandgap in the orange region of the visible spectrum. Under N2 ,the compound decomposes at 238° C, eventually losing approximately 46% total mass up to 1350° C. The exothermic decomposition in air, beginning at 235° C, results in the formation of titanium oxides.

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Analysis Of Ammunition By X-Ray Fluorescence, Michael W. Rapp, Teddy L. Townsend Jan 1994

Analysis Of Ammunition By X-Ray Fluorescence, Michael W. Rapp, Teddy L. Townsend

Journal of the Arkansas Academy of Science

Nondestructive analysis of lead shotgun pellets by X-ray fluorescence (XRF) shows considerable promise in assignment of the identity of the ammunition source. X-ray fluorescence spectra of various shotgun pellets and of standard alloys were obtained using an energy-dispersive instrument and an Am-241 source. The correlation obtained between the precent antimony in the standard alloys and the intensity of the Ka fluorescence peak from antimony was excellent. Peak areas from antimony in shotgun pellets were measured and compared to calibration plots from the standard alloys. The method was capable of distinguishing among lead-based alloys, such as ammunition, with antimony content as …

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Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac Jan 1994

Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac

Journal of the Arkansas Academy of Science

Initial studies involved the thermal decomposition profile of five polysulfide complexes in air up to 550 °C. Since our first report to the Academy in 1990, we have obtained the capability to run samples up to 1500°C under various gases. Thermal Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA)of a series of transition metal polysulfide complexes are presented. Compounds analyzed included Cp2TiS5 ,MoS9 2",MoOS8 2", Zn(S x ) 2", Cd(S x ) 2-, Fe2S122 - and NiS82.

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Fluid Dynamics Model Of Data Acquisition And Date Analysis For High-Energy Physics, Charles M. Byrd, Christine A. Byrd, Wilson H. Howe, W. J. Braithwaite Jan 1994

Fluid Dynamics Model Of Data Acquisition And Date Analysis For High-Energy Physics, Charles M. Byrd, Christine A. Byrd, Wilson H. Howe, W. J. Braithwaite

Journal of the Arkansas Academy of Science

No abstract provided.

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Ultrasound Assisted Oxidative Cleavage Of Alpha-Keto, Alpha-Hydroxy And Alpha-Halo Ketones By Superoxide, Yi Hong Cao, A. Toland, Dominic T.C. Yang Jan 1994

Ultrasound Assisted Oxidative Cleavage Of Alpha-Keto, Alpha-Hydroxy And Alpha-Halo Ketones By Superoxide, Yi Hong Cao, A. Toland, Dominic T.C. Yang

Journal of the Arkansas Academy of Science

No abstract provided.

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Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan Jan 1994

Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan

Journal of the Arkansas Academy of Science

No abstract provided.

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Compton Scattering Of Gamma-Rays From Electrons In Advanced Laboratory, Christine A. Byrd, Morgan T. Burks, Lawrence A. Yates, Wilfred J. Braithwaite Jan 1994

Compton Scattering Of Gamma-Rays From Electrons In Advanced Laboratory, Christine A. Byrd, Morgan T. Burks, Lawrence A. Yates, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

A kinematically-complete 2-body final state measurement of Compton scattering of 662-keV photons is presened, where both scattered photon energy and electron recoil energy are measured versus photon scattering angle, theta gamma. Passive collimation of the photon beam is avoided; each recoiling electron triggers a photon-scattering event providing active beam collimation. Recoiling electrons have low energies at small theta gamma, impairing electron detection efficiency. Examining the recoiling-electron energy spectra in coincidence with high-resolution gammas indicates a 1"x 1"NaI detector is superior to a 1"x1" NE-102 plastic scintillator as the active scattering material, for efficient recoil-electron detection. Electron efficiencies versus theta gamma …

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