Digital Commons Network^™

Laser-Assisted Charge-Transfer Collisions: K++Na, Y. P. Hsu, M. Kimura, Ronald E. Olson

Physics Faculty Research & Creative Works

A theory has been formulated to characterize charge-transfer collisions in the presence of an external laser field. The molecular-state-expansion method is used to describe the scattering process within the impact-parameter formalism. Electron translation factors are included in the molecular-state expansion so that the scattering wave function satisfies the correct boundary conditions. The theory is applied to the process K++NaK+Na+. In addition, we have made a detailed analysis of laser-assisted charge transfer for low-energy collisions. In this case, a Landau-Zener formula can be derived which shows that the cross section increases with decreasing incident energy. In general the laser coupling is …

Electron Capture In Pseudo-Two-Electron Systems: Ar8++He, M. Kimura, Ronald E. Olson

Physics Faculty Research & Creative Works

Molecular-structure calculations using the pseudopotential method have been performed on the (ArHe)⁸⁺ system. The cross section for single-electron capture in Ar⁸⁺+He collisions was calculated for energies from 20 eV to 10 keV/amu. The perturbed-stationary-state method [M. Kimura, H. Sato, and R. E. Olson, Phys. Rev. A 28, 2085 (1983)], modified to include electron translation factors appropriate to two-electron systems, was used. The total cross section is relatively energy independent with a value of approximately 2.5x10-15 cm2. The n=4 level of Ar⁷⁺ is found to be preferentially populated, with the 4f level being dominant. © 1985 The …

Faraday's Law Demonstration, Richard Sankovich

Physics Faculty Research & Creative Works

No abstract provided.

Raman Studies Of Heavily Implanted, Dye-Laser-Annealed Gaas, H. D. Yao, A. Compaan, Edward Boyd Hale

Physics Faculty Research & Creative Works

Raman scattering is used to study the annealing behavior produced by 10 nsec, 565 nm dye laser pulses in high dose ion-implanted GaAs. Samples were prepared with Sn and Cd implantations of 2, 5, and 10 x 1015 cm2. The Raman spectra indicate that the threshold for epitaxial growth lies between 0.2 - 0.3 J cm2. Best carrier activation (∼ 2%), however, is achieved at ∼1.6 J cm2 for the Sn-implanted sample (n-type). For Cd implantation the electrical activation appears to be very high ({greater-than or approximate} 50%) for low pulse energies({less-than or approximate} 0.3 J cm2) but decreases for …

The Spin‐Exchange Ferromagnet With Dipole And Quadrupole Interactions, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

Spin-Exchange Cross Sections For Hydrogen-Atomalkali-Metal-Atom Collisions, H. R. Cole, Ronald E. Olson

Physics Faculty Research & Creative Works

The pseudopotential molecular-structure method has been used to calculate the X1 and a3 interaction potentials for the alkali-metal-atom hydrogen-atom systems. These potentials were then used in a quantum-mechanical calculation to determine the spin-exchange cross sections in the energy range from 2.5x10-4 eV to 2.5 eV. The cross sections follow the general form Q1/2=a-b lnv. However, abundant structure on the cross sections is present due to orbiting resonances induced by the deeply bound well of the X1 molecular state. The spin-exchange cross sections range from 17x10-16 to 25x10-16 cm2 at room temperature for H(F=1) transferring to H(F=0) in collision with unpolarized …

Fourier Transforms Over Warped Domains., Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The Author Shows that There May Be an Advantage to Computing Fourier Transforms Over Warped Domains. an Example of Such an Improvement is Provided. It is Also Shown How the Fourier Transform May Be Evaluated from Data Observed over a Warped Domain.

The Rollamo 1985, University Of Missouri - Rolla

Yearbooks

No abstract provided.

The Effect Of Electrodes On The Thermally Stimulated Currents In Sodium Silicate Glass, Ruth Mogrovejo Cuzmar

Masters Theses

“Electrodes play an important role in the study of alkali ion motion in glasses when TSPC/TSDC techniques are used. Silver, gold and combinations of them were used in the study of Na⁺ motion in Na₂O·3SIO₂ glass. The lower temperature peak is not affected by any of these electrodes, so it is attributed to the bulk glass. A second and third peak are strongly dependent on the kind of electrode used. A gold anode is a blocking electrode, and a gold cathode, is partially blocking. There is a tendency for a space charge polarization to form when …

Sintering Of Catio₃ With The Addition Of Caco₃ And Lif, Surapol Pleekram

Masters Theses

"The densification of CaTiO₃ with the addition of 4.74, 5.90, 6.88 mol% CaCO₃ and 22 mol% LiF was investigated over the temperature range 800° to 1050°C, for sintering times ranging from 1 to 216 hours. It was found that CaCO₃ reacts with LiF and to form a liquid at a temperature of about 450°C. This liquid enhances the densification of CaTiO₃ . The densification process was followed by making weight loss, shrinkage and porosity measurements. The microstructural development was determined by scanning electron microscope examination of both fractured and polished surfaces. X-ray diffraction and DTA/TGA were …

An Evaluation Of Magnetic Field Shielding And Cross Talk For Various Cable Configurations, Amir Hossein Nafar

Masters Theses

"The effect of shield grounding on magnetic field coupling in coaxial and twisted pair cables, was studied for various positions of the ground connection at 50 KHz. For the case of only one end of shield grounded the attenuation was about 60 dB. Furthermore, the effect of frequency from 50-500 KHz was considered on three cases. Thus it was concluded that attenuation increases as frequency increases. A combined experimental and analytical investigation was also conducted to characterize the mechanism of cross talk between wires of ribbon cable and traces on printed circuit boards. Inductive and capacitive coupling were studied in …

The Effect Of The Degree Of Saturation On The Permeability Of A Compacted Clay To Organic Permeants, Mark Alan Harms

Masters Theses

"Relationships for permeability of kaolinite versus degree of saturation and permeability versus flow are developed for 0.005 N calcium sulphate, xylene and aniline permeants using the triaxial flexible wall permeameter. The clay was statically compacted at degrees of saturation of 50%, 75% and 100%. A gradient of 277 was used for the permeability tests.

The initial degree of saturation was inversely related to the permeability of the clay. Saturated clay samples were found to be virtually impervious to aniline and xylene. As the degree of saturation decreased, the permeability increased with the initial volume of flow equivalent to the volume …

Industrial Simulation With Animation, Edward T. Hammerand

Masters Theses

"This thesis examines and evaluates the new simulation language PCModel. Prior to the arrival of PCModel, simulation via computer typically resulted in pages of statistics compiled over the duration of the simulation. PCModel's approach is to simulate the model on the display before the user in real time. Additionally, user interaction is supported to allow changes to be made throughout the simulation run.

The evaluation of PCModel is accomplished through inspection of a pair of examples already simulated in a conventional simulation language. The examples show the relative strong and weak points of the language, as well as demonstrating how …

Interaction Of Electric And Magnetic Charges: Addendum, I. Adawi

Physics Faculty Research & Creative Works

The problem of a head-on collision between a spherically symmetric electric and magnetic charge is reconsidered. The assumption of the equality of the electric and magnetic forces made earlier is abandoned as it does not follow from the model. It is shown that the rotational angular momentum a charge acquires is determined by the amount of the angular momentum which the charge removes from the field by virtue of its extension. The interaction energy of each charge with the dipole it induces in the other charge is equal to the rotational energy of the charge itself. This results in simple …

Relative Fluorescence Efficiencies For The Dissociative Excitation Of Some Hg-Halides By N2(A ³Σu+), Laird D. Schearer

Physics Faculty Research & Creative Works

No abstract provided.

Computerized Scanning Auger Microprobe, T. J. Sommerer, Edward Boyd Hale

Physics Faculty Research & Creative Works

An Auger spectrometer has been automated using a microcomputer. Fundamental considerations in the design and choice of the computerized system are presented and should be of general interest. The spectrometer was a Physical Electronics Ind. model 545 scanning Auger microprobe. The microcomputer chosen was a Southwest Technical Products 6809 computer system. Hardware details are discussed with emphasis on the four computer-spectrometer interface boards. These boards are (1) Auger energy control board, which sets the Auger detection energy with its 16 bit digital-to-analog converter (DAC); (2) read Auger signal board, which reads the Auger signal intensity with its 12 bit analog-to-digital …

Effects Of Iron Implantation On The Aqueous Corrosion Of Magnesium, S. Akavipat, Edward Boyd Hale, C. E. Habermann, P. L. Hagans

Physics Faculty Research & Creative Works

The influence of the implantation of iron ions on the corrosion of magnesium and an AlZn-rich magnesium alloy (AZ91C) has been studied. Anodic polarization measurements in a dilute chloride-containing alkaline solution were used to evaluate corrosion resistance. A range of ion energies (50-180 keV) and doses (1016-2 x 1017 Fe+ ions cm-2) have been evaluated. Both the iron-implanted pure magnesium and the alloy AZ91C gave improved polarization measurements. A systematic positive shift of the open-circuit potential with increasing iron dose was found. In AZ91C at a dose of 1017 Fe+ ions cm-2, there was a + 0.6 V more noble …

A Study Of Shadow Contrast For A Grating, Steve Eugene Watkins

Masters Theses

"A theoretical and experimental investigation of the causes of the reduction of the contrast in the shadow of a grating has been made. The variation of the shadow contrast is shown to be different for the two causes--diffraction and divergence. The conditions which determine the dominant effect are presented. Also, the contrast pattern due to diffraction is shown to have a squared scaling law while the divergence pattern is shown to scale linearly. This understanding of the shadow contrast increases the versatility and usefulness of the shadow moire technique, an optical method for determining the topography of surfaces"--Abstract, page ii.

Solution To The Piecewise Linear Continuous Random Initial Value Problem For Burgers' Equation, Yin Chin Shih, X. B. Reed, Jr.

Chemical and Biochemical Engineering Faculty Research & Creative Works

A closed form solution to Burgers' equation on an infinite domain has been obtained for "random sawtooth" continuous initial conditions defined on a finite domain. The "turbulent" solution is then used to compute statistical measures such as skewness and flatness factors, energy decay rates, and the temporal evolution of velocity autocorrelations and energy spectra. © 1985 American Institute of Physics.

An Analysis Of The Lyophilization Process Using A Sorption‐Sublimation Model And Various Operational Policies, M. J. Millman, Athanasios I. Liapis, J. M. Marchello

Chemical and Biochemical Engineering Faculty Research & Creative Works

The freeze‐drying process is studied under various operational policies through the use of a sorption‐sublimation model. The operational policy that provides the shortest drying times keeps the pressure at its lowest value. The upper and lower heating plates are independently controlled so that the material constraints are encountered and held throughout the free water removal phase. Under certain conditions, and for the case of samples of small thickness, the sorbed water profiles may have segments whose bound water concentrations are higher than those at the start of the free water removal phase. It is shown that the criterion used in …

A Management Training Model For Engineers In Saudi Arabia, Majid Al-Kassabi

Doctoral Dissertations

“Great economic growth has occurred in Saudi Arabia in the last decade creating overwhelming demands for professionally trained people. The emerging Saudi professionals are mostly engineers who have been put in managerial positions without the benefit of managerial training.

Objectives of this research were 1) To identify the skills needed by engineers to become managers; 2) To identify problems and constraints inherent in management training programs; 3) To identify the impact of a model training program on the individual; and 4) The impact of a model training program on the firm.

A training program was implemented using an experimental group …

A Case Study Of The Management Of New Packaging Technologies, Richard Kirk Maguire

Masters Theses

"There has been a growing interest by industry in the functions of packaging management as packaging is being recognized as a greater factor in the overall success of a company.

This is a case study on the packaging management structure of one company and how the introduction of new packaging technology is handled by that company. The case study follows the history of the packaging department of the company and examines the current structure of the department. The study goes on to analyze the department's methods for handling old and new technologies and the reasons for doing so. A closer …

Evidence For Uncorrelated Electron Capture And K-Shell Excitation In S13++He Collisions, J. A. Tanis, E. M. Bernstein, M. W. Clark, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, B. M. Johnson, K. W. Jones, M. Meron

Physics Faculty Research & Creative Works

Evidence is presented for a two-step process in ion-atom collisions in which two independent interactions occur in a single encounter. Measurements for 15200-MeVS13++He collisions indicate that uncorrelated projectile K-shell excitation and capture of a target electron occur in a single collision with one target atom. The results are in reasonable qualitative agreement with theoretical predictions of this two-step process. © 1985 The American Physical Society.

Spin-1 Exchange-Interaction Model Of Ferromagnetism, Harry A. Brown

Physics Faculty Research & Creative Works

The spin-exchange operator for spin S=1 and a constant-coupling-like approximation are used to evaluate the thermodynamic properties of a system described by a two-spin Hamiltonian that includes dipole and quadrupole interactions. The dipole and quadrupole moments and the exchange energy are found as functions of temperature. There is a critical temperature, Tc, which depends on the coordination number of the lattice at which the system undergoes a second-order phase transition. Below Tc, both magnetic moments, simultaneously, take on nonzero values and have infinite derivatives there while the derivative of the exchange energy is discontinuous. Comparison is made with other results …

Erratum: Normalized Line Shapes For Far-Wing Continuum Spectra: The Rb-Xe Satellite Band (Physical Review A(1985) 32, 5 (3150-3152)), Ronald James Bieniek

Physics Faculty Research & Creative Works

Recent advances in experimental spectroscopy offer the promise of yielding much detailed information about molecular potentials and collisional interactions from a study of the light emitted or absorbed in the far wings of atomic lines. However, readily manipulable, accurate theoretical expressions and methods are needed to extract such knowledge. Straightforward formulas, based on the distorted-wave approximation, for the normalized emission intensity in the far wing of a pumped atomic line are given here. By normalizing theoretical spectra with respect to the strength of the atomic line, one obtains a convenient form for the analysis of experimental differential spectra that are …

Electron Capture By Slow Alq+ Ions Colliding With Hydrogen, R. A. Phaneuf, M. Kimura, H. Sato, Ronald E. Olson

Physics Faculty Research & Creative Works

Total electron-capture cross sections have been measured for collisions of Alq+ (q=210) with H and H2 in the 20120-eV/amu energy range. The general trend of the cross sections for both H and H2 is an approximately linear increase with ionic charge state. The Al²⁺+H and Al³⁺+H systems were investigated theoretically using the molecular-orbital method with a pseudopotential to represent the Al³⁺ ion core. Coupled-channel calculations realize good agreement with experiment. An anomalously small cross section for Al²⁺+H is attributed to the fact that of the 1 and 3 entrance channels, only the 1 …

A Continental Well-Aged Aerosol In The Guinean Savannah At The Level Of A Trough Along The Itcz, F. Desalmand, Josef Podzimek, R. Serpolay

Physics Faculty Research & Creative Works

Simultaneous measurements of Aitken nuclei, cloud condensation nuclei and aerosol particles sizes larger than 0.3 μm in the Guinean savannah during the dry season show an aerosol of very exceptional physical properties: numerous cloud condensation nuclei (2000-3000 per cm3) active at low supersaturation (or slight 'undersaturation'), absence of very small Aitken nuclei active at 180% of supersaturation and concentrations of large aerosol particles (D > 0.3 μm) between 30 and 60 per cm3. The analysis of the aerosol behavior during a 'typical' 24-hr period of the dry season and during a fog situation indicates that (1) the aerosol is a very …

Charge Transfer Of Hydrogen Ions And Atoms In Metal Vapors, T. J. Morgan, Ronald E. Olson, A. S. Schlachter, J. W. Gallagher

Physics Faculty Research & Creative Works

Cross sections and equilibrium fractions for energetic H+, H−, and H0 in collisions with metal vapor targets have been compiled and evaluated. Both experimental and theoretical results are reported. Sources of errors are discussed, and recommended values for the data are presented. © 1985, American Institute of Physics for the National Institute of Standards and Technology. All rights reserved.

Satellite Structure In Laser-Assisted Charge-Transfer Cross Sections, Y. P. Hsu, Ronald E. Olson

Physics Faculty Research & Creative Works

A six-state coupled-channel calculation has been performed on the laser-assisted charge-transfer collision H⁺+Na+Latin small letter h with stroke. A greatly enhanced charge-transfer cross section is observed for low-energy collisions if the photon energy is matched to the classical satellite frequency. This frequency is determined by the location of an extremum in the difference of potential energies between the laser-pumped initial and final molecular states. The stationary-phase method has been used to reproduce the general features and the magnitude of the cross-section structure. © 1985 The American Physical Society.

Growth Of Tungsten Selenide Films Through Pyrolytic Conversion And Anodic Electrooxidation Of Ammonium Selenotungstate ((Nh4)2wse4), R. D. Engelken, T. (Thomas) P. Van Doren, Jack L. Boone, A. K. Berry, A. Shahnazary

Electrical and Computer Engineering Faculty Research & Creative Works

WxSey thin films have been prepared by the spray pyrolysis and anodic electrodeposition of solutions of ammonium selenotungstate, (NH4)2WSe4, with y/x usually between two and three for the sprayed films and y x>>1 for the electrodeposited films. The sprayed films indicated regions of crystalline WSe2 and have optical absorbance spectra consistent with a mixture of WSe2, WSe3, and selenium. The electrodeposited films are totally amorphous, highly photoconductive, and have optical absorbance spectra typical of amorphous or vitreous selenium. The sprayed films transform into WO3 at temperatures greater than 350°C in the presence of oxygen wile the electrode-posited films tend …