Digital Commons Network^™

Homogeneous Nucleation Of Ethanol, John L. Schmitt, G. W. Adams, R. A. Zalabsky

Physics Faculty Research & Creative Works

The authors have used an expansion cloud chamber to measure homogeneous nucleation rate as a function of temperature and supersaturation in ethanol. Nucleation rates from 102 to 105 drops/cm3 sec were measured in the temperature range 252-272 °K. An empirical functional fit to the data is used to extrapolate for comparison with other data in the literature at a nucleation rate of 1 drop/cm3 sec and to compare with the predictions of the classical Becker-Doring homogeneous nucleation theory. A full listing of the data and thermodynamics constants used in the reduction of the data is given in an appendix. © …

A Note On The Use Of A Photoelectric Counter For Total Particle Counting, Josef Podzimek, Paul C. Yue

Physics Faculty Research & Creative Works

The ability of the Nolan-Pollak counter to function as a "total" particle counter was investigated. Comparison with the UMR Absolute Aitken Nuclei Counter operated at an expansion pressure ratio of 1.33 revealed that in mean, the N-P counter measurements (at an expansion pressure ratio of 1.21) were 30% less. This correction, however, depends on particle nature, concentration and size distribution and assumes that particle losses in the central part of the UMRAAN counter are negligible. © 1982.

The University Of Missouri-Rolla, Absolute Aitken Nucleus Counter, John L. Schmitt, James L. Kassner, Josef Podzimek

Physics Faculty Research & Creative Works

The authors discuss the expansion cloud chamber system known as the University of Missouri-Rolla-absolute Aitken nucleus counter. A review of the properties of an expansion chamber and how it creates a supersaturation are given and a critical examination is made of the assumptions in its operation, e.g. adiabaticity of the expansion. The design of the chamber is described in detail and an analysis of the propagation of errors is given for quantities measured and calculated. A short review of the performance of the chamber and some general comments relative to comparisons with other Aitken nucleus counting instruments are given. The …

Electron-Capture Collisions Of H+ With Ground- And Excited-State Na, M. Kimura, Ronald E. Olson, J. Pascale

Physics Faculty Research & Creative Works

Pseudopotential molecular-structure calculations have been used to obtain the low-lying interaction energies for NaH+. The wave functions were used to calculate accurate radial and rotational coupling matrix elements. Scattering calculations which include electron translational factors were performed using up to eight coupled channels for laboratory energies 0.1 to 10 keV. Electron capture from ground-state Na 3s yields cross sections in the 10-15-cm2 range of which the dominant products are H 2s and H 2p. Electron capture from excited Na 3p does not show an enhanced cross section relative to capture from the ground state even though the energy gap E(R=) …

Sequential Probability Ratio Tests For The Shape Parameter Of A Nonhomogeneous Poisson Process, Lee J. Bain, Max Engelhardt

Mathematics and Statistics Faculty Research & Creative Works

Sequential probability ratio tests for the shape parameter of one or more nonhomogeneous Poisson processes, with power intensity functions, are provided. The tests can be performed when the scale parameter is an unknown nuisance parameter; the effective loss of not knowing the scale parameter is one observation per process. The resulting tests can be expressed in terms of the maximum likelihood estimators of the shape parameters for the usual fixed sample procedure. A further advantage of the present approach is that the scale parameters for different processes, in the multiple sample procedures, need not be equal. Approximations for the operating …

An Applied Approach To Automatic Pressure Transient Analysis., Jeffrey Allan Joseph

Masters Theses

"A generalized digital approach to pressure transient (well-test) analysis is developed. The model is rigorously applicable to flow tests (pressure drawdown or injectivity of Newtonian liquids), and to pressure buildup or falloff tests provided the f low time prior to shut-in is large compared to the total shut-in time. However, buildup or falloff data may s till be analyzed if the above conditions are not satisfied, using the principles of superposition/desuperposition.

When plotted on logarithmic coordinates, pressure transient data generally assume a characteristic shape, indicative of flow behavior. Accurate computer analysis of this data requires its representation in concise mathematical …

Sessile Drop Studies Of Gallium On Alumina, Timothy John Snyder

Masters Theses

"The liquid-vapor and solid-vapor interfacial energies of the system Ga-Al₂O₃ were determined by the sessile drop technique. The interfacial energies were found to decrease with increasing temperature and P₀₂.

A maximum liquid-vapor interfacial energy of 581 ergs/cm² was found for a clean sessile drop at 1227°C. Values for Γ₀, the excess concentration of oxygen, were calculated for both the liquid-vapor and solid-liquid interfaces. The work of adhesion between molten Ga and Al₂O₃ was found to increase with decreasing P₀₂ with a maximum of 576 ergs/cm² occurring …

Current Concepts Of Cerebrovascular Disease - Stroke: Stroke And Drug Abuse, L. R. Caplan, D. (Daniel) B. Hier, G. Banks

Chemistry Faculty Research & Creative Works

This Review Summarizes Available Information Concerning Cerebral Vascular Complications of the Most Commonly Abused Substances and Discusses Possible Mechanisms of Vascular Injury and Cerebral Damage. Although Alcohol is Frequently Abused and May Have Important Cerebrovascular Effects, its Consideration is Beyond the Scope of This Review.

Rare-Gas, Collision-Induced Shifts Of The Nd States Of Sodium, D. J. Krebs, Laird D. Schearer

Physics Faculty Research & Creative Works

We have measured line shifts of the 3P-nD transitions in sodium induced by collisions with helium, argon, and krypton for n=5 to 18. The shifts of the diffuse series transitions increase rapidly with principal quantum number and asymptotically approach the limit predicted by the Fermi model at high quantum numbers. © 1982 The American Physical Society.

Molecular Treatment Of Electron Capture By Protons From The Ground And Excited States Of Alkali-Metal Atoms, M. Kimura, Ronald E. Olson, J. Pascale

Physics Faculty Research & Creative Works

Electron-capture cross sections for H+ plus alkali-metal atom (Na, K, Rb, and Cs) systems have been computed for projectile energies from 10 eV to 10 keV. An impact parameter perturbed-stationary-state theory using molecular states that incorporate electron translation factors was used to calculate the cross sections. The wave functions were generated by employing the pseudopotential method. These yield equilibrium parameters Re and De for the A +2 molecular state that are in good agreement with ab initio results. Interaction energies are also presented for the LiH+ system. Basis sets of up to eight molecular states were used to calculate the …

A Study Of Poly(P‐Xylylene)‐Coated Asf5‐Doped Polyacetylene, J. E. Osterholm, H. Yasuda, L. L. Levenson

Physics Faculty Research & Creative Works

Electrical conductivity measurements and scanning electron microscopy have been used to study uncoated and poly(p‐xylylene)‐coated samples of polyacetylene doped with AsF5. These initial results indicate a considerable reduction in the decay rate of conductivity in the presence of oxygen as well as a decreased rate of thermal decomposition of the dopant when heated between 50°C and 115°C in vacuum by the coating. Copyright © 1982 John Wiley & Sons, Inc.

High Pressure Liquid Jet Nozzle System For Enhanced Mining And Drilling, B. P. Selberg

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This invention is directed to a nozzle configuration capable of enhancing the cutting and drilling effects of high pressure liquid fluid jets. The jet system is particularly adapted to configurations of two or more liquid jets which are oriented to converge at a common point. The internal nozzle configuration produces controlled instability in the jet stream causing a more rapid breakup into droplets which can be combined to produce very fast moving jets and slow moving jets when collision between droplets occur. The velocity of the fast jets so formed may be several times greater than the original velocity of …

Drawing Characteristics Of Electrogalvanized Steel Wires., Chi-Yuan Tsao

Masters Theses

"As a means of investigating the often adverse drawing behavior of electrogalvanized steel wire, drawing experiments were conducted on a variety of industrially-supplied and laboratory-prepared electroplated steel wires. Back-flow and shaving appeared to be the mechanisms by which sizeable zinc losses occurred. Performance during drawing and the quality of the product depended upon both the characteristics of the plating and the drawing process variables. Grain size, grain texture, and surface 'flatness' can affect the required drawing force, surface finish and level of zinc retention. Low die angles and large reductions offered greatest efficiencies with minimum zinc loss"--Abstract p. ii

Chemical Corrosion Of Ag Films On Glass, Hyun Soo Park

Doctoral Dissertations

"The chemical corrosion of chemically, vacuum and sputter deposited Ag films on an aluminoborosilicate and a soda lime glass was investigated in wet HCl and saturated water vapor as a function of concentration, temperature and time. The higher corrosion resistance of chemically deposited Ag films in comparison to evaporated or sputtered Ag films is attributed to their lower microvoid density and higher adhesion strength. Ag films on the more chemically durable aluminoborosilicate glass had a higher corrosion resistance. Furthermore, films which received a moderate thermal annealing (80 to 140° C) or were deposited on a glass surface washed with HN0 …

Relative Volatilities Of The Ethane-Ethylene System From Total Pressure Measurements, David A. Barclay, Judith L. Fiebbe, David B. Manley

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new apparatus has been developed for making vapor pressure measurements on high-pressure systems. Using this equipment, we have made a large number of new total pressure measurements on the ethane-ethylene binary from 198.15 to 278.15 K. By Integration of the general coexistence equation, relative volatilities have been calculated for ethane-ethylene over the entire temperature range. © 1982, American Chemical Society. All rights reserved.

Vapor Pressures Of Some C4 Hydrocarbons And Their Mixtures, Judith L. Flebbe, David A. Barclay, David B. Manley

Chemical and Biochemical Engineering Faculty Research & Creative Works

New experimental vapor pressures for the six binary systems containing 1,3-butadlene, n-butane, trans -2-butene, and c/s-2-butene at temperatures from 278 to 358 K are reported. Relative volatilities were calculated by using the Isothermal general coexistence equation. © 1982, American Chemical Society. All rights reserved.

The Anodic Dissolution Of Zns Electrodes In Sulfuric Acid Solutions, Ram A. Narasagoudar, James W. Johnson, Thomas J. O'Keefe

Chemical and Biochemical Engineering Faculty Research & Creative Works

The anodic dissolution of reagent grade ZnS and ZnS concentrate has been studied. The majority of the research was conducted in H₂SO₄ although a limited number of tests were made in HCl and KOH. Polarization studies showed that both Zn²⁺ and S were products in the acidic solutions. ZnS passivated in KOH solutions. The electrodes were fabricated by hand pressing mixtures of ZnS + pitch (5-15%) and sintering at 800°C in a N2 atmosphere. The open circuit potentials were considered to be mixed potentials resulting from the anodic dissolution of ZnS and cathodic reduction of S …

Ethanol Densities Between −50 And 20 °C, Mark R. Schroeder, Bruce E. Poling, David B. Manley

Chemical and Biochemical Engineering Faculty Research & Creative Works

The density of ethanol was measured between −50 and 20 °C to ±0.01%. The measurements were made by using a procedure similar to ASTM D1217-54, "Standard Method of Test of Density and Specific Gravity of Liquids by Bingham Pycnometer". The results were correlated by the equation in D = −0.215231 − (1.05037 x 10−3)T − (7.837 x 10−7)T2 − (7.47 x 10−3)T3 (D in g/cm3, T in ° C). © 1982, American Chemical Society. All rights reserved.

A Dwba Study Of Atom-Diatom Rearrangement Collisions, Randall Wayne Emmons

Doctoral Dissertations

"The role of the transferred angular momentum in state-to-state atom-diatom reactive scattering is investigated. Using the F+H₂ reactive system in this model study, it is found that many features in the state-testate differential and total cross-sections can be qualitatively explained. In particular, a maximum total cross-section occurring in a vibrational manifold of HF can be shown to occur due to an angular momentum match"-- Abstract, p. ii

Comparative Study Of The Boundary Element Technique And The Finite Element Method In Two Dimensional Eigenvalue Problem, Farough Baradari

Doctoral Dissertations

"In this work we investigate the applicability of a "Boundary Element method 11 for the numerical solution of the Liouville and Helmholtz eigenvalue problem for different two-dimensional geometries including a typical reactor configuration. The method is based on the discretization of the unknown along the boundary and Green's function representation of the governing equation.

To compare the capability of this method with the finite element method, a finite element code which uses quadratic quadrilateral isoperimetric elements was developed. A boundary element code was also written. These codes were used to determine the fundamental eigenvalue for several two-dimensional geometries -- square, …

The Heterogeneous Nucleation Of Ice On Ion Implanted Silicon, William Henry Stinebaugh

Doctoral Dissertations

"Ice crystal nucleation on 1 80 keV Si⁺ ion implanted silicon was investigated experimentally at three different temperatures: T = - 20 °, - 24 °, and -30 ° C. The ion doses ranged from 4 .0 x 10¹⁴ ions/cm² to 5 .0 x 10¹⁵ ions/cm². The supersaturation dependence of ice nucleation on the ion implanted samples at these three temperatures was observed by controlling the substrate temperature and relative humidity independently.

An enhanced ice nucleation activity was observed on samples implanted with ion doses in the range of (1.6 - 2.0) x 10 …

Gaseous Reactions In Heteroporous Media, Elmer Anthony Klavetter

Doctoral Dissertations

"A modified dusty-gas model which accounts for the effects the pore-size and tortuosity distributions have on the mass fluxes in heteroporous media is presented. The behavior of the dusty-gas model (homoporous model) can be obtained from the modified model when the pressure is either very low or very high as well as for intermediate pressures when the characteristic parameter of the introduced tortuosity function has a very small value. When the pressure is very high or very low, all pores in the porous medium are almost in a single transport regime of either molecular or Knudsen diffusion.

Comparisons of the …

Extensions, Generalizations, Characterizations And Testing For Independence Through Infinite Divisibility, Edward Joul Danial

Doctoral Dissertations

This dissertation investigates various related topics around the exciting concept: "Infinite Divisibility." First, two intricate distributions, namely, the univariate generalized Waring and the hyper-Poisson are proved to be infinitely and noninfinitely divisible, respectively. Analysis and computer approaches are employed. This itself extends the use of some results introduced by Katti, Steutel and Warde. Secondly, generalizations to Warde, Katti and Steutel's sufficient conditions and related results are achieved. Then, numerical application is presented. Thirdly, characterizations through infinite and finite divisibility are obtained. The Poisson, negative binomial, geometric, Bernoulli and uniform c haracterizations in terms of infinite divisibility are deduced. Some of …

Mineralogical, Textural, And Paragenetic Studies Of Selected Ore Deposits Of The Southeast Missouri Lead-Zinc-Copper District And Their Genetic Implications, Kenneth Bruce Horrall

Doctoral Dissertations

“A detailed paragenetic study of Pb-Zn-Cu ores from the Viburnum Number 28, Brushy Creek, and Goose Creek mines in the Southeast Missouri lead district indicates a complicated paragenesis characterized by repeated periods of mineral deposition. The sequence is composed of nineteen minerals including abundant galena, sphalerite, chalcopyrite, pyrite, marcasite, dolomite, calcite, and quartz and minor siegenite, bornite, bravoite, blaubleibender covellite, covellite, gersdorffite, digenite, enargite, tennantite, dickite, and malachite.

The paragenesis indicates that the ore solutions evolved in the following order: (1) Cu-rich, (2) Co-Ni-rich, (3) Pb-Zn-rich, and (4) Fe-rich. Subsequent repeated generations include cubic galena, later sphalerite, and minor crystalline …

On The Curie Temperatures Of Amorphous Ferromagnets, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

Production Of Highly Charged Rare-Gas Recoil Ions By 1.4-Mev/Amu U44+, A. S. Schlachter, W. Groh, A. Müller, H. F. Beyer, R. Mann, Ronald E. Olson

Physics Faculty Research & Creative Works

Recoil-ion-production cross sections in rare gases are measured for 1.4-MeV/amu U44+ ions and are calculated for 1-5-MeV/amu projectiles in charge state 44 + with the use of the classical-trajectory Monte Carlo method and the independent-electron model. The calculations reasonably predict the net-charge-production cross sections, which exceed 10-13 cm2 for the heavy rare gases; the calculations are found to underestimate the cross sections for low-charge-state recoil ions and to overestimate the cross sections for high-charge-state recoil ions. The experimental cross sections for production of highly charged recoil ions are found to be large, e.g., greater than 1x10-16 cm2 for production of …

Electron Density Measurements In A Laser Induced Na Plasma, D. J. Krebs, Laird D. Schearer

Physics Faculty Research & Creative Works

The optical emission spectrum of a recombining Na plasma is observed. The shift and broadening of the spectral line emission due to electron collisions is observed. Electron densities on the order of 5x1014 cm -3 are calculated from the shift measurements. The results agree well with electron densities obtained in the same system from Saha plots of excited state densities. © 1982 American Institute of Physics.

Determination Of The Absolute Structure Factor For The Forbidden (222) Reflection In Silicon Using 0.12-Γ Rays, R. W. Alkire, W. (William) B. Yelon, J. R. Schneider

Physics Faculty Research & Creative Works

A room-temperature determination of the absolute structure factor for the forbidden (222) reflection in silicon has been conducted at the University of Missouri Research Reactor with 103-keV gamma rays. The measured structure factor of F(222)=1.456 is in excellent agreement with five of the earlier intensity measurements and is significantly different from any value determined using Pendellösung techniques. An increase in accuracy over previous intensity measurements by a factor of between 2 and 10 has been achieved and is made possible through the use of monoenergetic, short-wavelength gamma rays, which allow absolute measurements to be made in Laue geometry on relatively …

Comparison Of Several Aitken Nuclei Counters, Josef Podzimek, John C. Carstens, P. C. Yue

Physics Faculty Research & Creative Works

The basic thermodynamical processes leading to the formation of droplets in the central part of the Nolan-Pollak counter are analyzed in some detail. The comparison of the UMR-Absolute Aitken Nuclei counter with Nolan-Pollak, General Electric and Gardner counters showed consistently higher counts of the UMR-AAN counter. The mean deviations varied between 20% and 50% depending on the type of the counter, nuclei concentration and nature. Several observations are made on ultrafine particle counting. © 1981.

A Potential Problem With The Tsi Electrostatic Aerosol Classifier, Darryl J. Alofs, Max B. Trueblood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.