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University of Arkansas, Fayetteville

Journal

1995

Articles 1 - 15 of 15

Full-Text Articles in Physical Sciences and Mathematics

Recreational And Angler Survey Of The Buffalo National River, Arkansas, James E. Johnson Jan 1995

Recreational And Angler Survey Of The Buffalo National River, Arkansas, James E. Johnson

Journal of the Arkansas Academy of Science

The Buffalo River in northern Arkansas was surveyed for recreator and angler use in 1991 and 1992. The river was divided into three reaches and numbers of boats, recreators, anglers, and catches were compiled by creel clerks at nine selected take-out points. Outfitter rental receipts were used to estimate rental boats, and the proportion of rental to private boats creeled was used to correct for private boats not counted on the rental receipts. A total of 1,656 boats containing 3,071 recreators was contracted by the creel clerks during 1991 and 1992; 9.2% of the recreators were anglers. Expansion of the …

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Arkansas' Wellhead Protection Program, With Discussion Of Delineation Methodology, Robert Cordova, Bobby Makin Jan 1995

Arkansas' Wellhead Protection Program, With Discussion Of Delineation Methodology, Robert Cordova, Bobby Makin

Journal of the Arkansas Academy of Science

The Wellhead Protection (WHP) program was authorized by the 1986 Amendments to the Safe Drinking Water Act. The Arkansas Department of Health in July, 1986, was designated by Governor Clinton to be the lead agency in carrying out the WHP program. The program is designed to protect the ground-water resource tapped by public water-supply wells from contaminants which are injurious to the public health. It is the first formal attempt by the federal government in its environmental protection role to prevent contamination from taking place, in contrast to costly clean-up or remediation programs. Among its several requirements, the program includes: …

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Hammett Correlations Of Carbonyl 13c Chemical Shifts In A Series Of N-(4-Substituted Phenyl)-6-Chloro-5-Fluoronicotinamides, Frank L. Setliff, John W. Hawley, Alan D. Toland Jan 1995

Hammett Correlations Of Carbonyl 13c Chemical Shifts In A Series Of N-(4-Substituted Phenyl)-6-Chloro-5-Fluoronicotinamides, Frank L. Setliff, John W. Hawley, Alan D. Toland

Journal of the Arkansas Academy of Science

A series of nine N-(4-substituted phenyl)-6-chloro-5- fluoronicotinamides exhibited excellent correlations of their carbonyl 13C shifts (5CO,ppm as measured in DMSO) with the standard Hammett substituent constants (c?R) of the substituent inthe 4-position. The linear relationship was defined by the equation 8CO ¦ 1.22

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Creation And Implementation Of A Tracking Module For A Small-Geometry, Vertex Time Projection Chamber, Christine A. Byrd, Wilson H. Howe, Amber D. Climer, Wilfred J. Braithwaite Jan 1995

Creation And Implementation Of A Tracking Module For A Small-Geometry, Vertex Time Projection Chamber, Christine A. Byrd, Wilson H. Howe, Amber D. Climer, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

A charged-particle tracking module was written and tested using pixel data generated from CERN's Monte Carlo detector-modeling program GEANT. This tracking module was customized for testing the design of a micro-strip gas time project chamber, designed by Drs. Margetis and Wieman of the Relativistic Nuclear Collisions Group at Lawrence Berkeley Laboratory. This low-mass, high-resolution, small-geometry vertex time projection chamber was designed for possible use with a larger instrument in an experiment using the relativistic heavy ion collider, RHIC, under construction at Brookhaven National Laboratory in New York. Implementing this tracking module involved generating tables and source code in a manner …

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Scf-Mo Conformational Analysis Of Polycroconaine, T. E. Ezell, Jerry A. Darsey Jan 1995

Scf-Mo Conformational Analysis Of Polycroconaine, T. E. Ezell, Jerry A. Darsey

Journal of the Arkansas Academy of Science

Abinitio calculations at the STO-3G basis set level using GAUSSIAN 92 were conducted on the monomer unit of polycroconaine, a conducting polymer with conductive properties similar to several metals, in order to determine the most probable conformation of the monomer. We also compared the energy difference between the highest occupied and lowest unoccupied molecular orbitals. Successive calculations were performed at dihedral angle intervals of 30° around the central bond of the monomer. Minimum energy was observed at 0° bond rotation, consistent with a theory that the polymer owes many of its conductive properties to a planar configuration in combination with …

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Proforce Waves: The Effect Of Current Behind The Shock Front On Wave Structure, Mostafa Hemmati, Steven Young Jan 1995

Proforce Waves: The Effect Of Current Behind The Shock Front On Wave Structure, Mostafa Hemmati, Steven Young

Journal of the Arkansas Academy of Science

Recently, the initial boundary conditions for proforce waves with a substantial current behind the shock front have been derived. Computer solutions of the Electron Fluid Dynamical equations meet the expected boundary conditions at the end of the sheath region. This paper will compare the wave structure for proforce waves with and without current behind the shock front.

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Critical Energy Of Torus Knots, Fred Hickling, Wesley Davis, Heather Woolverton Jan 1995

Critical Energy Of Torus Knots, Fred Hickling, Wesley Davis, Heather Woolverton

Journal of the Arkansas Academy of Science

The energy of a smoothly parameterized knot y(t) is defined as rr\ i i lp7 \\dn dsdt Jo Jo \||7M-7(0f (D(t(s),T(t))) 2 j\\ds \\dt where D(y (s), y(t)) is the arc length between the two points y (s) and y(t) on the curve. Simple calculus based arguments are used to locate critical values of the energy functional for torus knots. Explicitly the curves given parametrically by °(«*)W = (V2°iSri).JSSBe V2 C s7nS are CriticalP ° intS ° fthe energy functional whenever a and b are relatively prime.

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Optimizing Tracking Software For A Time Projection Chamber, Wilson H. Howe, Christine A. Byrd, Amber D. Climer, Wilfred J. Braithwaite, Jeffrey T. Mitchell Jan 1995

Optimizing Tracking Software For A Time Projection Chamber, Wilson H. Howe, Christine A. Byrd, Amber D. Climer, Wilfred J. Braithwaite, Jeffrey T. Mitchell

Journal of the Arkansas Academy of Science

International research collaborations will be using accelerators in the U.S. and Europe to produce and detect t5 phase transition in high-density nuclear matter called the Quark-Gluon Plasma, formed in collisions between pairs of A=200 nuclei, for projectiles with kinetic energies large compared to their rest mass energies. Each collaboration will use time projection chambers (TPC) to track thousands ofsecondary charged particles formed in the aftermath ofeach central primary collision. Creating and optimizing TPC tracking software is difficultinsuch a high multiplicity environment, particularly for particles with a low momentum (below 300 MeV/C). A thigh momenta, energy loss is low enough for …

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Introduction To Monte Carlo Methods, Sue Ellen Mccloskey, Wilfred J. Braithwaite Jan 1995

Introduction To Monte Carlo Methods, Sue Ellen Mccloskey, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

Monte Carlo computer programming is becoming increasingly popular to those who use it, due to the ease with which complex problems may be formulated and solved. However, the growth of MC programming for small projects is inhibited by a frequent misconception of difficulty, inferred from the high level of complexity of problems solved in High Energy and Nuclear Physics using MC methods. In addition, few students of science and engineering are receiving exposure to the basic issues involved in the Monte Carlo process despite the ease with which MC can be used to solve classical physics problems, especially those problems …

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Spectroscopic Temperature Measurements For A Direct Current Arcjet Diamond Chemical Vapor Deposition Reactor, Scott W. Reeve, Wayne A. Weimer Jan 1995

Spectroscopic Temperature Measurements For A Direct Current Arcjet Diamond Chemical Vapor Deposition Reactor, Scott W. Reeve, Wayne A. Weimer

Journal of the Arkansas Academy of Science

The diamond thin filmcommercial market isprojected to exceed one billion dollars by the year 2000. Potential applications of diamond thin films range from cutting tools to electronics tomedical devices. The explosion ofinterest in this fieldresults from the extreme properties diamond possesses: itis the hardest material known toman and yet, has a coefficient of friction similar to Teflon;its ability to conduct heat is five times that of copper; and diamond is completely inert. However, despite the tremendous economic incentive, there are still several technological barriers preventing diamond filmscale-up to commercial production. Included among these are a fundamental understanding of the gas …

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Drift Chamber Utilizing Microstrip Readout For Testing A New Micro Tpc Concept, H. Weiman, W. G. Gong, S. Margetis, M. T. Burks, Wilfred J. Braithwaite, A. A. Rollefson Jan 1995

Drift Chamber Utilizing Microstrip Readout For Testing A New Micro Tpc Concept, H. Weiman, W. G. Gong, S. Margetis, M. T. Burks, Wilfred J. Braithwaite, A. A. Rollefson

Journal of the Arkansas Academy of Science

A drift chamber type radiation detector is being used to examine design criteria for a new type of detector called a micro Time Projection Chamber (micro TPC) which is being proposed for use in high energy nuclear physics experiments. The main advantage of the micro TPC detector is its very low radiation thickness compared to its silicon counterpart. The micro TPC is a charged-particle detector which willbe optimized for good two track resolution which is needed inahigh track density environment. Such performance requires low electron diffusion and high resolution readout. The diffusion willbe reduced bylimiting the drift distance to 15 …

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Using Geant To Model Calrimeter Response For Electromagnetic Cascades From Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Kazuhiko Murai, Carlos A. Sanchez, Donald C. Wold Jan 1995

Using Geant To Model Calrimeter Response For Electromagnetic Cascades From Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Kazuhiko Murai, Carlos A. Sanchez, Donald C. Wold

Journal of the Arkansas Academy of Science

Ascintillating optical fiber calorimeter (SOFCAL) is being developed by NASA/Marshall Space Flight Center for use in balloon-borne experiments to study the spectrum of high-energy cosmic rays and gamma rays. SOFCAL will not saturate for long exposures and the calorimeter willbe useful in emulsion chambers to study primary cosmic-ray nuclei with energies from 100 GeV to 1,000 TeV. The event generator FRITIOF was used to model the collision of a cosmic-ray projectile with a target nucleus inan emulsion chamber. The measurements of charged particles from the interaction in the emulsions are related to the energy of the primary cosmic ray nucleus-nucleus …

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Using Fritiof To Model Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Carlos A. Sanchez, Kazuhiko Murai, Donald C. Wold Jan 1995

Using Fritiof To Model Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Carlos A. Sanchez, Kazuhiko Murai, Donald C. Wold

Journal of the Arkansas Academy of Science

Ascintillating optical fiber calorimeter (SOFCAL) isbeing developed by NASA/Marshall Space Flight Center for use in experiments to study the spectrum of high-energy cosmic rays and gamma rays from 100 GeV to 1,000 TeV. SOFCAL willnot saturate for long exposures and this calorimeter inthese balloon-borne emulsion chambers willbe helpful for the study of the composition of primary cosmic-ray nuclei. For primary nuclei with energies much greater than 1014 eV, nucleus-nucleus interactions are likely to exhibit characteristics of a quark-gluon plasma (QGP). Aparticle event generator was used tomodel the collision of a cosmic-ray nucleus with a target nucleus inan emulsion chamber. FRITIOF …

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Conceptual Basis For An Index Of Forest Integrity For Upland Coastal Plain Ecosystems, Nicholas R. Brown, Brian Roy Lockhart, Philip A. Tappe, Lynne C. Thompson, Robert C. Weih Jr., Richard A. Williams Jan 1995

Conceptual Basis For An Index Of Forest Integrity For Upland Coastal Plain Ecosystems, Nicholas R. Brown, Brian Roy Lockhart, Philip A. Tappe, Lynne C. Thompson, Robert C. Weih Jr., Richard A. Williams

Journal of the Arkansas Academy of Science

Following the recent trend to manage natural resources for "sustainability," ecologists, resource managers and policymakers are beginning to think of the management of forest ecosystems in terms of "ecosystem health" or "ecosystem integrity." Biologists are increasingly recognizing that use of chemical assays in assessing the condition of an ecosystem has limited value, and that biological factors, e.g., species diversity and composition, can be useful characters in the analysis of "biotic integrity." An index of biotic integrity (IBI) has been developed for riverine ecosystems in the Midwest U.S., using fish species diversity, indicator population analysis, trophic structure assessment, and physiological abnormalities …

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Energy-Loss Particle Identification In 2-D Silicon Drift Detectors, G. Douglas Maudlin, A. A. Rollefson, Wilfred J. Braithwaite Jan 1995

Energy-Loss Particle Identification In 2-D Silicon Drift Detectors, G. Douglas Maudlin, A. A. Rollefson, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

A relatively new type of transducer known as the Silicon Drift Detector (SDD) has been fabricated onto thin silicon wafers. SDD operates like a miniature, high-resolution, 2-D Time-projection chamber. One of these devices can detect two dimensions of an ionizing particle's position, and its integrated electrical charge output level isproportional to the particle's energy loss through the silicon. An array ofSDD's, arranged in three coaxial cylinders, is being considered as part of an instrument surrounding the beam pipe of highly-relativistic colliding beam facility, where it would be used to simultaneously track individual paths of thousands of charged particles emerging from …

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