Digital Commons Network^™

The Missouri Miner, November 01, 1989

The Missouri Miner Newspaper

No abstract provided.

Low- And High-Relief Leduc Formation Reefs: A Seismic Analysis, Neil Lennart Anderson, Robert James Sidford Brown, Ronald C. Hinds

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Leduc reefs have grown to widely varying heights and aereal extents along the Rimbey-Meadowbrook trend of central Alberta, resulting in significantly different seismic signatures. Three examples considered in this paper include two high-relief or full reefs from the Leduc-Woodbend field, an atoll and a pinnacle, each around 200 m in height but differing greatly in areal extent, about 100 km² for the atoll and 1 km² for the pinnacle. The third example, a low-relief or basalt reef from the Morinville field, is about 100 m high and 1 km² in areal extent.

The Leduc-Woodbend and Morinville reefs …

The Missouri Miner, October 25, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, October 18, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, October 11, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, October 04, 1989

The Missouri Miner Newspaper

No abstract provided.

Analysis Of Experimental Nucleation Data For Silver And Sio Using Scaled Nucleation Theory, Barbara N. Hale, Paul R. Kemper, Joseph A. Nuth

Physics Faculty Research & Creative Works

The experimental vapor phase nucleation data of Nuth et al., for silver [J. A. Nuth, K. A. Donnelly, B. Donn, and L. U. Lilleleht, J. Chem. Phys. 77, 2639 (1982)] and SiO [J. A. Nuth and B. Donn, J. Chem. Phys. 85, 1116 (1986)] are reanalyzed using a scaled model for homogeneous nucleation [B. N. Hale, Phys. Rev. A 33, 4156 (1986)]. The approximation is made that the vapor pressure at the nucleation site is not diminished significantly from that at the source (crucible). It is found that the data for ln S have a temperature dependence consistent with the …

Quantum Transport In The Presence Of Random Traps, John Wm Edwards, Paul Ernest Parris

Physics Faculty Research & Creative Works

We calculate the asymptotic decay of a quantum particle moving in a d-dimensional medium doped with randomly placed trapping impurities, focusing on contributions from slowly decaying long-wavelength modes centered in large compact regions devoid of traps. By averaging the decay over the statistical distribution associated with these regions we find that the survival probability, P(t) ~exp(-At^d/(d+3)), decays more slowly in any dimension than for diffusive transport.

The Missouri Miner, September 27, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, September 20, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, September 13, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, September 06, 1989

The Missouri Miner Newspaper

No abstract provided.

Aluminum Deposition On Polyimides: The Effect Of In Situ Ion Bombardment, M. J. Vasile, Bonnie Bachman

Economics Faculty Research & Creative Works

The chemistry of the Al polyimide interface is examined by x‐ray photoelectron spectroscopy sputter profiling. Al deposited on polyimide films without an in situ Ar backsputter shows a clearly defined 50‐Å Al₂O₃ layer just prior to the polyimide. This layer is identified by the O/Al atom ratio at 1.5, and the binding energy of the Al 2p transition. There is a clear separation of the Al/Al₂O₃/polyimide layers in the sputter profiles. Deposition of Al on polyimide surfaces after Argon backsputtering produces a diffuse Al/polyimide interface with no Al₂O₃ present. There …

One-Dimensional Quantum Transport In The Presence Of Traps, Paul Ernest Parris

Physics Faculty Research & Creative Works

A study is made of the survival probability P(t) for a quantum particle moving coherently on an ordered one-dimensional chain containing randomly placed irreversible traps in concentration q. We consider two separate models of the trapping process, focusing on the long-time limit of each. In the first model, intended to describe substitutional traps, the trapping impurities act as disruptive absorbing barriers which prevent further motion along the chain. For this model it is shown that -ln[P(t)]1/4t^1/4. The second model is intended to describe interstitial trapping impurities which do not disrupt the transport. It is argued for this case …

Full Optical Potential For The Electron-Hydrogen Entrance Channel, Igor Bray, Don H. Madison, Ian E. Mccarthy

Physics Faculty Research & Creative Works

Differential and total elastic and total reaction cross sections are calculated for electron-hydrogen scattering at 30, 100, and 400 eV using an ab initio optical potential that treats bound and continuum nonelastic channels in the distorted-wave Born approximation. Multichannel and partial wave expansions are carried out to numerical convergence. Convergence criteria and quadratures for the continuum-energy integration are chosen for 1% overall accuracy. Results are compared with experiment and less detailed calculations.

Mocvd Of Cds Onto (111) Silicon Substrates, Jack L. Boone, Scott A. Howard, Don D. Martin, Gene Cantwell

Electrical and Computer Engineering Faculty Research & Creative Works

Thin films of CdS were grown onto (111) silicon substrates (wafers 2 in in diameter) by employing a horizontal, low-pressure MOCVD system. The observed growth of heteroepitaxial films occurred in the temperature range of 275-325 ±5 °C. The growth of polycrystalline samples with a high degree of preferred orientation occurred at temperatures above 325 ± 5 °C. The later films exhibited irregularly shaped surface pits about 1 μm in depth. These pits were observed by sectioning the substrates and examining them with an SEM; no significant crystallinity was apparent. X-ray analysis of an heteroepitaxial and a polycrystalline film via a …

The Missouri Miner, August 30, 1989

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, August 23, 1989

The Missouri Miner Newspaper

No abstract provided.

Load And Resistance Factor Design Of Cold-Formed Steel Load And Resistance Factor Design Specification For Cold-Formed Steel Structural Members With Commentary, Ling-En Hsiao, Wei-Wen Yu, Theodore V. Galambos

CCFSS Library (1939 - present)

FOREWORD This progress report contains the following two parts: Part I: Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. i-107). Part II: Commentary on the Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. 109-161). The load and resistance factor design specification proposed herein is the revised version of the design recommendations prepared in February 1988 and submitted to American Iron and Steel Institute as Tenth Progress Report. This document was prepared according to the 1986 edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members. The selections of ϕ …

Design Of Automotive Structural Components Using High Strength Sheet Steels The Effect Of Strain Rate On Compressive Mechanical Properties Of Sheet Steels, Maher Kassar, Wei-Wen Yu

CCFSS Library (1939 - present)

INTRODUCTION Since May 1988, the research project on automotive components sponsored by American Iron and Steel Institute (AISI) at University of Missouri-Rolla (UMR) has been concentrated on a study of the effect of strain rate on mechanical properties of sheet steels and the structural behavior and strength of cold-formed steel members subject to impact loads. The results of the tensile dynamic mechanical properties of three selected sheet steels, in the virgin condition as well as for the steels subjected to different amount of cold stretchings, were estabiished in 1988 and early 1989. Details of the tension coupon tests were presented …

Resonant Dielectronic And Direct Excitation In Crystal Channels, Sheldon Datz, Charles Randy Vane, Peter F. Dittner, J. P. Giese, J. C. Gomez Del Campo, N. L. Jones, Herbert F. Krause, Philip D. Miller, Michael Schulz, Harald Schone, Thomas M. Rosseel

Physics Faculty Research & Creative Works

We have observed dielectronic and direct excitation of H-like S¹⁵⁺ and Ca¹⁹⁺ and He-like Ti²⁰⁺ ions in silicon channels caused by collision with weakly bound target electrons which behave as a free-electron gas. As in vacuo, relaxation of the doubly excited states can occur radiatively leading to ions of decreased charge, but in a crystal channel collisional effects can cause double ionization. The effects are seen in both the x-ray yields and charge-state fractions, and, in the case of Ti²⁰⁺, in charge-state x-ray coincidences.

Missouri S&T Magazine, August 1989, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Evaluation Of The Base Test Method For Predicting The Flexural Strength Of Standing Seam Roof Systems Under Gravity Loading, Thomas M. Murray, Steven D. Brooks

CCFSS Library (1939 - present)

No abstract provided.

Single And Double-Electron Removal From H− In Energetic Collisions With Multiply-Charged Argon Ions, F. Melchert, W. Debus, M. Liehr, Ronald E. Olson, E. Salzborn

Physics Faculty Research & Creative Works

Absolute cross-sections have been measured and compared to CTMC-calculations for single and double-electron removal from H− in collisions with Ar^q+ ions (q ≤ 8) at E_c.m. = 50 keV. The single-electron removal cross-sections are found to scale with q^1.3, and for the H⁻ + Ar⁴⁺ system, this cross-section is found to have a weak energy dependence from 3 keV to 100 keV. A major implication of our measurements is that plasma neutralizers based on multiply charged ions for high-efficiency conversion of intense H⁻ beams into H⁰ gain little in expected reduced …

Ion Bombardment Of Polyimide Films, Bonnie Bachman, M. J. Vasile

Economics Faculty Research & Creative Works

Surface modification techniques such as wet chemical etching, oxidizing flames, and plasma treatments (inert ion sputtering and reactive ion etching) have been used to change the surface chemistry of polymers and improve adhesion. With an increase in the use of polyimides for microelectronic applications, the technique of ion sputtering to enhance polymer‐to‐metal adhesion is receiving increased attention. For this study, the argon‐ion bombardment surfaces of pyromellitic dianhydride and oxydianiline (PMDA–ODA) and biphenyl tetracarboxylic dianhydride and phenylene diamine (BPDA–PDA) polyimide films were characterized with x‐ray photoelectron spectroscopy (XPS) as a function of ion dose. Graphite and high‐density polyethylene were also examined …

Missouri S&T Magazine, June 1989, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

The Missouri Miner, May 03, 1989

The Missouri Miner Newspaper

No abstract provided.

Automated Translation Of Digital Logic Equations Into Optimized Vhdl Code, John Evan Stark, George Winston Zobrist

Computer Science Technical Reports

It was desired to develop an algorithm for the automated translation of finite slate machines from state table form to optimized VHDL form. To do this, algorithms arc needed for reducing the state machine to simplest form, making state assignments, producing minimal logic equations to represent the state machine, and producing VHDL code which describes the intended circuit. Various such algorithms were examined and a prototype program written to perform this translation.

Long-Range Hopping In Substitutionally Disordered Solids, Paul Ernest Parris

Physics Faculty Research & Creative Works

A theoretical approach for studying charge-carrier and energy diffusion due to long-range hopping in substitutionally disordered solids is presented. Unlike some earlier theories, which invoke a pair approximation to treat back-transfer processes, the current theory makes use of the exact solution to an appropriate single-defect problemone in which long-range jumps into, out of, and between both the defect site and all other active sites in the lattice are explicitly included. From this exact solution a new long-range effective-medium theory is constructed to describe the configurationally averaged transport properties of the disordered system.

Spectroscopy Of The 6p3/2Np States Of Barium, J. Greg Story, E. G. Yap, William E. Cooke

Physics Faculty Research & Creative Works

The 6p_3/2np states of barium have been observed for n values between 14 and 21. The energies, linewidths, and transition strengths have been measured and characterized in terms of one- and two-electron interactions, using a single-configuration approximation.