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Ion‐Pair Theory Of Concentrated Electrolytes. Iii. Variational Principle, Frank Stillinger, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

Two major contributions are devised for that theory of concentrated electrolytes which by convention regards the ions as completely paired into uncharged dipolar “molecules.” First, a more satisfactory expression is obtained for the wavelength‐dependent static dielectric “constant” ε(k). Second, a variational principle for Helmholtz free energy F is displayed whose minimization with respect to the ion‐pair size distribution p(1) serves to determine both F and p(1). In anticipation of future numerical applications, a binary collision approximation is specified for the short‐range interaction aspect of the functional F[p(1)].

Ion‐Pair Theory Of Concentrated Electrolytes. Iv. Ion Atmosphere Charge Distribution, Frank Stillinger, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

Arguments are presented indicating that the large‐size limiting behavior of the ion‐pair size distribution is qualitatively the same both with, and without, Coulomb interactions between ions. This in turn implies that the static dielectric response function ε0 / ε(k) derived in the preceding paper is nonanalytic at k = 0. The specific singular behavior of this response requires a branch cut along the imaginary k axis. It furthermore induces an r−8 tail in the ion atmosphere charge distribution at finite electrolyte concentration.

Construction Of A Small Vacuum Ultraviolet Spectrograph, Dale A. Eding

Masters Theses

No abstract provided.

Hydrostatic Pressure Effects On The Epr Spectrum Of V2+:Al203, Jonathan Lloyd Albain

Masters Theses

No abstract provided.

An Experimental Investigation Of The Vortex Sink Rate Sensors, Nelson L. Lu

Mechanical & Aerospace Engineering Theses & Dissertations

The vortex sink rate sensor device consists basically of an ideal sink flow between two coaxial disks. A sink tube was located at the center of one disk. The vortex was created by the rotation of the unit about its axis of symmetry. Five inch and 10 inch diameter of porous couplers were used for the air chamber here in this investigation. Several slenderness parameters, i.e., the ratio of the sink tube diameter to the height of the air chamber ^ro/n were conducted. Two probes were used to measure the static pressure and stagnation pressure respectively at various positions …

Lorentz-Invariant And Lorentz-Noninvariant Approximation Techniques In The Spin-Parity Analysis Of Four-Pion Resonances, Wilson C. Lu

Masters Theses

No abstract provided.

Length And Velocity Formulas In Approximate Oscillator-Strength Calculations, Anthony F. Starace

Anthony F. Starace Publications

The matrix element for electric dipole transitions is correctly given by the length formula in the Hartree-Fock, configuration-interaction, and related approximations, which involve the diagonalization of an approximate, but nonlocal, Hamiltonian.

Spectroscopic Measurement Of The Electron Temperature In The Tenuous Argon Ion Laser Plasma, Dane Danijel Bicanic

Physics Theses & Dissertations

The validity of the line intensity ratio technique for measuring the electron temperature was examined for an argon plasma with a "population inversion" i.e., the number of ions with electrons in the upper 4p levels was greater than in the lower 4s levels. The line intensities from these levels, the argon ion lasing transitions, were measured in a pulsed tenuous plasma at 110μ Hg produced by discharging a capacitor through a tube 2m long and 7mm inside diameter. The electron impact cross sections for simultaneous excitation and ionization as measured by Latimer and St. John were used and averaged over …

Mössbauer Spectroscopy Study Of The Spin‐Flop Transition In Fe‐Doped Mnf2, C. R. Abeledo, Richard B. Frankel, A. Misetich, N. A. Blum

Physics

Measurements of the hyperfine interaction in Fe^{+ +} in MnF₂ in external fields above the spin‐flop field at 4.2 K are reported and a value of g⊥ = 2.13 is derived, in good agreement with theory.

Track Theory And Radiation Quality, Robert Katz

Robert Katz Publications

Radiation detection and damage data from several physical, chemical, and biological systems have been analyzed by a unified track theory, in which observed effects are attributed to the interaction of secondary electrons with the medium. Gamma-ray dose-response curves are combined with calculations of the spatial dose distribution about an ion's path to yield dose-response curves (survival curves) for heavy ion bombardment, through appropriately defined parameters. Perplexing phenomena associated with high LET radiation are sorted out according to track regime (grain-count or track-width), inactivation mode (gamma-kill or ion-kill), structural complexity (elementary, cellular, multicellular), and end-point. The central problem in assigning a …

Low-Lying Even-Parity Resonances In Ki:Ag+, Roger D. Kirby

Roger Kirby Publications

Lattice resonances of E_g symmetry (16.35 cm^-1) and A_1g symmetry (25 cm^-1) have been found in KI:Ag⁺ using far-infrared spectroscopic techniques. The two even-parity modes are found to be anharmonically coupled to the T_1u^- symmetry resonant mode at 17.3 cm^-1, giving rise to the combination bands observed at 30 and 44.4 cm^-1.

Mössbauer Effect In Fe-Doped Kmgf3, J. Chappert, J. R. Regnard, Richard B. Frankel, A. Misetich, N. A. Blum

Physics

An iron-doped KMgF₃ single crystal has been studied with the Mössbauer technique. The two charge states, Fe²⁺ and Fe³⁺, are observed. Below 12 °K an Fe²⁺ quadrupole doublet appears. Using Ham strain model we calculate that the first excited spin-orbit level lies ~ 120 cm^-1 above the Γ_5g ground state.

Isomeric Shift Of The 83 Kev Transition In 153Eu, E. Ansaldo, L. Grodzins, Richard B. Frankel

Physics

No abstract provided.

Far-Infrared Properties Of Lattice Resonant Modes. V. Second-Order Stark Effect, B.P. Clayman, Roger D. Kirby, A. J. Sievers

Roger Kirby Publications

Small electric-field-induced frequency shifts have been observed for resonant modes associated with three defect systems. For NaI: Clˉ, the shifts have been used to measure the quartic anharmonic terms of the interionic potential of the impurity ion. For KBr: Li⁺, the quartic anharmonic terms are found to be very small, and an harmonic potential which includes a central barrier with the barrier height less than the zero-point energy of the oscillator is required to explain the experimental results. For NaCl: Cu⁺, only an "on-center" resonant-mode configuration is consistent with the experimental results.

Simulation Of Particle Tracks In Emulsion, Thomas E. Furtak, Robert Katz

Robert Katz Publications

Micrographs of energetic particles in nuclear emulsion are simulated by computing the spatial distribution of developed grains with the δ-ray theory of track structure, and representing the developed grains by points of light on an IBM 2250 visual display unit. The simulated tracks display many of the features of actual track structure and serve as a visual comparison between experiment and theory,

Lamb-Mössbauer Factor Of Sodium Ferrocyanide, Daniel L. Decker, L. E. Lortz

Faculty Publications

Using a set of commercially prepared sodium ferrocyanide absorbers enriched to 91.2% Fe57 the Lamb-Mössbauer factor was measured to be 0.28±0.03. The thickness of Fe57 for these absorbers was measured using x-ray absorption techniques and was found to be considerably smaller than that advertised by the manufacturer even after correcting for the size of the ferrocyanide particles in the absorbers.

Dielectric Polarization And Alignment And The Structure Of Polar Fluids, John D. Ramshaw, D. W. Schaefer, John S. Waugh, J. M. Deutsch

Physics Faculty Publications and Presentations

An analysis is made of the information about the structure of dense polar fluids which resides in the dielectric constant, the Kerr constant, and the nuclear magnetic resonance (NMR) quadratic electric field effect. The inadequacy of the "local-field" model for liquids is discussed. The existence of a nonzero molecular hyperpolarizability is shown to destroy an equivalence which would otherwise exist between the Kerr and NMR experiments, and can easily account for apparent discrepancies between the reported Kerr and NMR data for nitrobenzene and nitromethane. A method is presented for removing dielectric boundary effects from statistical averages, so that the averages …

A Vibrational And Rotational Analysis Of Eight Simple Models Of The Hydrogen Molecule In The Ground State., Stuart Fleming Hayes

Physics & Astronomy ETDs

The object of this dissertation was the investigation of the influence on the delta G curve for H2 of polarization, enhancement of charge between the nuclei, and variation of the screening parameter. A better understanding of the influence of these factors could lead to progress in estimating more accurately the dissociation energies of diatomic molecules. Also to be investigated was the correlation between these factors and the vibrational and rotational spectroscopic constants, particularly Bv.

The Heitler-London combination of atomic orbitals (referred to as phi 1) was used in every wave function The atomic orbital 2pz was used in phi 2 …

A Variable Coeficient Of Restitution Experiment On A Linear Air Track, R. Gruebel, James C. Dennis, L. Choate

Faculty Publications

A system consisting of two pendula attached to an air cart is mathematically analyzed, and the coefficient of restitution is shown to pass through a deep minimum. The solution to the small angle equation of motion is transcendental and provides an exercise in graphical methods for the beginning mechanics student.

The Impulse And Doublet, Richard C. Heyser

Unpublished Writings

The basic problem to which this paper is directed is that of characterization of the acoustic field perceived by an observer and due to a loudspeaker situation in a room. Before immediately jumping into an apparent solution and presenting the results of a set of measurements it is essential to present the considerations leading to that measurment...First, there are at least two ways of characterizing the same acoustic signal if we restrict our attention to a well defined set of parameters...Secondly, since both characterizations define the same thing it must be possible to translate information without loss from one domain …

Observation Of Quadrupole Splitting Of B-12 In A Single Crystal, R. L. Williams Jr., Richard C. Haskell, Leon Madansky

All HMC Faculty Publications and Research

The quadrupole coupling of B-12 implanted in Be-9 has been observed using a single crystal of Be. One sees a narrow resonance line, the location of which depends in the normal way on the orientation of the crystalline c-axis with respect to the external magnetic field direction. The coupling constant is given by e2qQ/h = 54.9(6) kHz. This is consistent with our previous measurement using a Be foil. Using the field gradient at Be-9 lattice sites, calculated by Pomerantz and Das, one finds Q(B-12) = about 34.6 mb.

Properties Of The Interstitial In The Diamond-Type Lattice, G D. Watkins, R P. Messmer, C Weigel, David Peak, J W. Corbett

All Physics Faculty Publications

Linear combination of atomic orbital—molecular orbital cluster calculations using extended Hückel theory suggest that the interstitial carbon atom in diamond prefers an "interstitialcy" configuration. The predicted minimum-energy configuration changes with charge state, providing a possible example of the Bourgoin mechanism for "athermal" migration of the interstitial in the presence of ionizing radiation.

Angular And Energy Distribution Of Cross Sections For Electron Production By 50-300-Kev-Proton Impacts On N2, O2, Ne, And Ar, J. B. Crooks, M. Eugene Rudd

M. Eugene Rudd Publications

Cross sections differential in angle and ejection energy for electron production by proton impact on nitrogen, oxygen, neon, and argon have been measured using electrostatic analysis and counting of individual electrons. The range of proton energies was 50-300 keV, the angles ranged from 10° to 160°, and the electron energies were measured from 1.5 to 1057 eV. Integrations over angle and/or electron energy yielded singly differential and total electron production cross sections. Our total cross sections for oxygen fall halfway between previous data of deHeer et al. and Hooper et al., but our argon cross sections agree better with deHeer …

Recent Meetings-Nebraska Section, Robert Fuller

Robert G. Fuller Publications

The fall meeting of the Nebraska Section of the AAPT was held 31 October 1970 at the University of Nebraska in Lincoln. The sessions were chaired by Professor Clyde Sachtleben, Hastings College.

Measurement Of Nuclear Magnetic Dipole Moment Of Li-8 By Implantation In Metal Foils, Richard C. Haskell, R. L. Williams Jr., Leon Madansky

All HMC Faculty Publications and Research

Polarized 8Li nuclei have been produced through the 7Li(d,p) reaction using the 3.5-MeV Van de Graaff accelerator at Brookhaven National Laboratory. The observed polarization was a slowly-varying function of deuteron energy over the range 1.3-2.9 MeV, reaching a maximum of about +1.6%. The recoiling nuclei were stopped in Au, Pt and Pd foils and the effective dipole moments were measured by a resonant depolarization method. The results were 1.65362(22)µN, 1.65288(20)µN and 1.65270(30)µN respectively. These are consistent with the work of Connor, who found µ(8Li) =1.6530(8)µN in a LiF crystal. An upper limit for the 8Li quadrupole moment will also be …

Electron-Impact Excitation Of Auto-Ionizing Levels In Cesium, Yu Bong Hahn, Kaare J. Nygaard

Physics Faculty Research & Creative Works

Auto-ionizing states in Cs between 12 and 20 eV have been studied by electron impact. The retarding-potential-difference method was used to obtain an electron beam with energy spread of about 0.1 eV. To determine the threshold energies, inelastically scattered electrons were analyzed by the trapped-electron method. We have been able to identify about 20 levels, and the agreement with spectroscopic data is excellent. A peak appearing at 12.80 eV is probably due to the quartet states observed by Feldman and Novick. © 1971 The American Physical Society.

Scattering Of Waves In Many Dimensions, I. Adawi

Physics Faculty Research & Creative Works

Scattering by a spherical potential is discussed in all dimensions by one formulation using the partial-wave expansion method. The optical theorem relating the total scattering cross section σ to the forward scattering amplitude f(0) is derived.

Experimental And Theoretical Study Of The Sign Preference In The Nucleation Of Water Vapor, Daniel R. White, James L. Kassner

Physics Faculty Research & Creative Works

The nucleation of water vapor on ions in atmospheres of helium and argon was studied using an expansion type cloud chamber. Separation of the positive and negative ions was achieved so that the nucleation could be studied as a function of both the sign of the ionic charge and the supersaturation. A semiphenominological theory was developed as an extension of the classical liquid drop theory to include the effects of the ionic charge on the nucleation process. The theoretical model of the prenucleation embryo was assumed to possess an oriented dipole surface layer with the direction of orientation dependent on …

Heisenberg Ferromagnet With Biquadratic Exchange, Harry A. Brown

Physics Faculty Research & Creative Works

The usual Heisenberg Hamiltonian with bilinear exchange -2JS→1•S→2 has been extended to include a biquadratic term -2αJ(S→1•S→2)2, with an adjustable parameter α. A method equivalent to constant coupling was employed to calculate the effect of the biquadratic exchange term on the Curie temperature, magnetization, susceptibility, specific heat, and entropy for lattices with spin-1 atoms. As α goes from 0 to 1, the Curie temperature falls by a factor 2 to 3, while the asymptotic Curie temperature is reduced by the factor 2. The magnetization rises much more rapidly below TC, and the specific heat has a peak and discontinuity several …

Excitation Of The 2s State Of Atomic Hydrogen By Electron Impact In The Distorted-Wave Approximation - Angular Distributions, W. Neil Shelton, E. S. Leherissey, Don H. Madison

Physics Faculty Research & Creative Works

The excitation of ground-state hydrogen atoms to the 2s state by the impact of electrons with energies of 1 to 50 Ry (13.6 to 680.3 eV) has been calculated in the distorted-wave approximation with exchange included. The angular distributions of the scattered electrons at 1 and 4 Ry are compared with those derived from the close-coupling calculations by Burke, Schey, and Smith, and are compared with four different plane-wave theories at all energies calculated. Taking the close-coupling results as a standard, it is found that the distorted-wave angular distributions represent an improvement over those of the plane-wave theories.