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Path Integrals With Arbitrary Generators And The Eigenfunction Problem, William B. Campbell, Paul Finkler, C. E. Jones, M. N. Misheloff

Paul Finkler Papers

We generalize the path integral formalism of quantum mechanics to include the use of arbitrary infinitesimal generators, thus providing explicit expressions for solutions of a wide class of differential equations. In particular, we develop a method of calculating the eigenfunctions of a large class of operators.

Theory Of Impurity-Induced Infrared Absorption In Cubic Crystals, S. S. Jaswal, J. M. Wadehra

Physics and Astronomy Faculty Research Publications

A method to calculate the infrared absorption due to a very low concentration of defects in a diatomic cubic crystal is developed directly from the basic absorption equation in quantum mechanics when the impurity produces changes in mass and short-range force constants. It is shown that the absorption is due to the modes of T_1u symmetry about the defect and is proportional to the square of the projection of the amplitudes of the ions in the defect space onto the transverse-optic modes at the zone center as determined by the perturbation. A procedure to calculate the amplitudes of …

A Satellite Study Of The High Energy Proton Environment Under The Radiation Belt, Kailash Chandra Dhingra

Physics & Astronomy ETDs

Proton data outside of the South Atlantic Radiation anomaly (in the regions where h_min < 0) from the University of New Mexico High Energy Neutron and Proton Detector aboard OSO-6 satellite were analyzed in the present work. The detector was useful in the energy range from 75-145 Mev and the data were obtained during the period from August 1969 to January 1971. The altitude of the satellite varied from about 480 Km to 580 Km. Since the observed proton flux resulted from different source mechanisms a procedure was developed that allowed us to compute and separate the contributions made by different mechanisms in the observed protons. New evidence was derived from the study of the Down-Up asymmetry both along the field direction and the zenith of the look direction (ZAP angle) which substantiated the hypothesis that either one or both of the processes of the radial and the pitch angle diffusion play active roles in the origin and the distributions of the protons in the inner radiation belt. It was argued that processes drive the trapped protons in the radiation belt into the regions where stable trapping is not possible and thus contribute to the observed protons in these regions. We were further able to compute the total diffusing flux; however, it was assumed that both the Splash and the Re-entrant albedo proton fluxes were equal. Since this assumption was not very accurate, an incorrect estimation of the diffusing proton flux might have resulted. In addition to the above, the flux and the energy spectrum of the albedo protons were derived at three different regions. These were then compared with the results of other investigators. Discrepencies in both the flux and the energy spectrum were observed. Our flux value of 1.05 protons/m² -sec-ster-Mev for the Re-entrant albedo at an energy of 85 Mev in the region where L = 2.5 was about a factor of two and a half higher than estimated by Ray (1967). No west-east asymmetry was observed in the true proton flux (proton flux obtained by subtracting the background contamination from the observed proton flux), within the limits of the experimental error. Since such an asymmetry was expected if we assume that the albedo protons alone constitute the true protons, it was concluded …

Double Rainbow And Dark Band In Searchlight Beam, J. Harsch, Jearl D. Walker

Physics Faculty Publications

No abstract provided.

Rbe-Dose Relations For Neutrons And Pions, Robert Katz, S. C. Sharma

Robert Katz Publications

RBE-Dose relations have been calculated from cellular radiosensitivity parameters and theoretical particle-energy spectra in tissue, of the secondary particles from neutron and negative pion irradiations. The theoretical results are compared with clinical and radiobiological data for normal tissue, tumors, and cells in culture. Formulae for calculation, cellular parameters, and the needed properties of equivalent “track-segment bombardments” are given, for several mammalian cells irradiated with pions and with neutrons of several energies.

Résumé
Rapports EBR-dose pour neutrons et pions
A partir des paramètres de la radiosensitivité cellulaire et du spectre théorique, dens le tissu, de l’énergie d’atomes secondaires provenant d’irradiations de …

Temperature Dependence Of Magnetoresistance In Ni3al System, Paul D. Hambourger, R. J. Olwert, C. W. Chu

Physics Faculty Publications

The transverse magnetoresistance of stoichiometric and off-stoichiometric polycrystalline samples of the Ni3Al system has been measured over the temperature range 1.2C. The data are in qualitative agreement with the theoretical predictions of Chang et al. based on a model of the magnetoresistance of an itinerant ferromagnet, but the observed magnetoresistance is considerably larger than predicted.

Quadrupole Couplings Of N12 And B12 Implanted In Metal Single-Crystals, Richard C. Haskell, Francis David Corell, Leon Madansky

All HMC Faculty Publications and Research

Measurements have been made of the quadrupole couplings of 12N implanted in single crystals of Be and Mg and of 12B implanted in a single crystal of Zn. A comparison of the 12N couplings in Be and Mg suggests that (i) the final stopping sites of the implanted 12N ions are substitutional sites, i.e., the 12N ions occupy metal-ion lattice positions, and (ii) the 12N ions implanted in Be and Mg have the same charge state and quadrupole shielding factor. A procedure is outlined for deducing Q(12N). The 12B couplings in Zn imply the existence of two inequivalent stopping sites. …

Binary Nucleation. I. Theory Applied To Water-Ethanol Vapors, Gerald Wilemski

Physics Faculty Research & Creative Works

A quantitative study of nucleation in vapor mixtures of ethanol and water near 273°C is presented. First, Reiss' theory of binary nucleation is reexamined. The theory is modified slightly in order to yield the proper limit for homogeneous nucleation in a one-component system. Moreover, a corrected expression for the equilibrium concentration of mixed clusters is derived. Calculations of the critical vapor activities needed to produce a visible condensate are presented and compared with the results of Flood's cloud chamber experiments. The agreement is only fair, but qualitative accord is found.

Damage Analysis Modified Trac Computer Program (Damtrac), George H. Baker Iii, Alan D. Mcnutt, G. Bradford Shea, David M. Rubenstein

School of Integrated Sciences - Faculty Scholarship

A computer program tailored for EMP damage analysis of solid-state circuitry has been developed by modifying the existing TRAC network analysis program. Modification of the TRAC diode and transistor models to include breakdown parameters and the addition of a semiconductor device parameter library have greatly simplified the analyst's task. An added feature is a subroutine that automatically calculates the amplitude and duration of transient power dissipated in electronic circuit components.

Effects Of Anisotropic Electron-Ion Interactions In Atomic Photoelectron Angular Distributions, Dan Dill, Anthony F. Starace, Steven T. Manson

Anthony F. Starace Publications

The photoelectron asymmetry parameter β in LS coupling is obtained as an expansion into contributions from alternative angular-momentum transfers j_t. The physical significance of this expansion of β is shown to be that (i) the electric-dipole interaction transfers to the atom a characteristic single angular momentum j_t=l₀, where l₀ is the photoelectron's initial orbital momentum, whereas (ii) angular-momentum transfers j_t≠l₀ indicate the presence of anisotropic (i.e., term-dependent) interaction of the outgoing photoelectron with the residual ion. For open-shell atoms the photoelectron-ion interaction is generally anisotropic; photoelectron phase shifts …

Binary Nucleation. Ii. Time Lags, Gerald Wilemski

Physics Faculty Research & Creative Works

The role of the time lag needed to attain steady state nucleation in binary vapors is discussed. Under appropriate conditions it is possible to obtain both a large predicted rate of binary nucleation and a large time lag. In this circumstance, homogeneous nucleation of the more concentrated component may be the predominant process. It is of obvious importance to the experimentalist to differentiate between these possibilities. Approximate formulas for the time lags are developed, and representative calculations for the ethanol-water system are reported.

Application Of Generalized Ellipsometry To Anisotropic Crystals, R. M.A. Azzam, N. M. Bashara

Electrical Engineering Faculty Publications

No abstract provided.

Linear Chain Compounds: Metamagnetism In Co(Pyr)2Cl2, Fe(Pyr)2Cl2, Fe(Pyr)2(Ncs)2 And Ni(Pyr)2Cl2, S. Foner, Richard B. Frankel, E. J. Mcniff, Jr., W. M. Reiff, B. F. Little, Gary J. Long

Physics

We report the observation of low field metamagnetic behavior in powder samples of Co(pyr)₂Cl₂, Fe(pyr)₂Cl₂, Fe(pyr)₂(NCS)₂ and Ni(pyr)₂Cl₂ where pyr=pyridine. These materials have linear chain structures with strong ferromagnetic interactions along the chains, and relatively weak antiferromagnetic interactions between chains. In all four compounds the transitions were observed as a rapid increase in the magnetic moment with increasing magnetic field. In Fe(pyr)₂Cl₂, Fe(pyr)₂(NCS)₂, and Ni(pyr)₂Cl₂, the transitions at 4.2 K were observed at 0.7 …

Ohmic Contacts To Al‐Implanted Znse, B. K. Shin, David C. Look, Y. S. Park

Physics Faculty Publications

No abstract provided.

Mossbauer Measurements With '"Au In Aua1„Auga„Auin„And Ausb, John O. Thomson, Felix E. Obenshain, Paul G. Huray, John C. Love, John W. Burton

Aerospace, Physics, and Space Science Faculty Publications

Mossbauer spectra for '"Au in Au metal and the intermetallic compounds AuAl„AuGa„AuIn„and AuSb2 have been obtained for the temperature range 4.2 to 95'K. The isomer shifts for these absorbers with respect to a ' Au in Pt source are —1.223(2) [Au metal], + 2.288(12) [AuSb2], + 3.489(4) [AuIn2], +4.450(11) [AuGa, ], and +.5.967(5) [AuAl, ] in units of mm/sec. The difference in isomer shifts (alloy-Au-metal) may be interpreted in terms of an increasing electron charge density at the Au nucleus in the alloys as compared to that of Au metal. When volume changes for the alloys with respect to the …

Ellipsometric Function Of A Film-Substrate System: Applications To The Design Of Reflection-Type Optical Devices And To Ellipsometry, R. M.A. Azzam, A.-R. M. Zaghloul, N. M. Bashara

Electrical Engineering Faculty Publications

The ratio ρ = R_p/R_s of the complex amplitude-reflection coefficients R_p and R_s for light polarized parallel (p) and perpendicular (s) to the plane of incidence, reflected from an optically isotropic film-substrate system, is investigated as a function of the angle of incidence ϕ and the film thickness d. Both constant-angle-of-incidence contours (CAIC) and constant-thickness contours (CTC) of the ellipsometric function ρ(ϕ,d) in the complex ρ plane are examined. For transparent films, ρ(ϕ,d) is a periodic function of d with period D_ϕ that is a function of ϕ. …

Differential Cross Sections For Elastic And Inelastic Scattering Of 15-100-Kev Li⁺ By He, John T. Park, Victor Pol, James E. Lawler, Jacob M. George, John E. Aldag, John W. Parker, Jerry Peacher

Physics Faculty Research & Creative Works

Sets of energy-loss spectra for Li⁺ incident on He that were taken at a series of scattering angles were used to calculate differential cross sections. Differential cross sections are given for elastic scattering and for excitation of the He (n=2) states. The differential cross section is also given for excitation of states corresponding to a 60-eV energy loss. These inelastic differential cross sections exhibit maxima at scattering angles greater than zero. The velocity dependence of the cross sections can be compensated by displaying the elastic data in ρ-vs-τ plots and the inelastic data in ρ-vs-E^3/2θ plots. When …

Hyperfine Interactions In Mgf2:Fe2+ And Znf2:Fe2+ By Mössbauer Spectroscopy, C. R. Abeledo, Richard B. Frankel, A. Misetich

Physics

Measurement of the magnetic hyperfine interaction in paramagnetic Fe²⁺ in ZnF₂ and MgF₂ by Mössbauer spectroscopy is reported. The results, −275 ± 3 kOe and −270 ± 3 kOe for ZnF₂:Fe²⁺ and MgF₂:Fe²⁺ respectively are compared with a previous analysis of hyperfine interactions in the rutile fluorides.

Studies In Artificial Rain: Their Progress And Prospects, P. B. Vitta

Tanzania Journal of Science

The progress made by studies of the phenomenon of rain is reviewed. Several techniques for modifying clouds so as to accelerate rain-drop precipitation are described.

An Attempt To Control Boundary Layer Turbulence With Nonisotropic Compliant Walls, R. Grosskreutz

Tanzania Journal of Science

A review of turbulence production in boundary layers leads to a new approach to boundary layer control by means of nonisotropic compliant walls. Suitably constructed coatings were tested and demonstrate that the concept is basically valid.

Fluid Mechanics In The Elementary Laboratory, James C. Dennis

Faculty Publications

No abstract provided.

Temperature-Dependence Of Electron Mean Free Paths In Tungsten, Paul D. Hambourger

Physics Faculty Publications

No abstract provided.

An Introduction To The Film, Personalized System Of Instruction: An Alternative, Instructional Media Center, University Of Nebraska-­Lincoln

Personalized System of Instruction (PSI), or Keller Plan, Materials

Who should see PSI: An Alternative ?

• Academic classroom instructors from all departments
• Junior college and college administrators
• Teaching method specialists
• Students in schools of education
• Media specialists
• Secondary school educators

You should see PSI: An Alternative.

A digital file of the 14-minute film is attached (below) as a Related File.

Kinetic Theory Of Gases

Calculus-Based General Physics

As you read this sentence you will experimentally demonstrate the general gas law at least once by breathing in and out. As you expand the volume in your lungs, the pressure drops and air comes in; as you decrease the lung volume the pressure rises and air goes out. Pressure (p) and volume (V) are related; at constant temperature, pV = const.

This relation, called Boyle's law, was well established before the atomic theory of matter was accepted. In this module you will learn how to apply much of your knowledge of Newton's laws, kinetic energy, momentum, and elastic collisions …

Response Of Nuclear Emulsions To Ionizing Radiations, Robert Katz, F. E. Pinkerton

Robert Katz Publications

Heavy ion tracks in Ilford K-2 emulsion are simulated with a computer program that makes use of the delta-ray theory of track structure, and the special assumption that the response of the emulsion to gamma-rays is 8-or-more hit. The Ilford K-series of nuclear emulsions is produced from a parent stock called K.0 emulsion, sensitized to become K.1 to K.5, and desensitized to become K–1 to K–3. Our simulations demonstrate that the emulsions K.5 through K.0 to K-1 are 1-or-more hit detectors, while K-2 is an 8-or-more hit detector. We have no data for K-3 emulsion. It would appear that emulsions …

Electric Fields And Potentials From Continuous Charge Distributions

Calculus-Based General Physics

Too bad! In case you have not realized it, not all charges come packaged as points, spheres, infinite cylinders, or infinite planes. Ah, if only it were so: Life would be much easier from a calculational viewpoint, although somewhat limited in geometrical options. But then, mechanics would be simpler if only constant accelerations were observed in nature ... Not to mention centers of mass; moments of inertia, etc.; all would be considerably simpler to calculate in that wonderful world of point masses, constant accelerations, massless strings, and frictionless boards.

Once again calculus is needed to assist us in analyzing and …

Coulomb's Law And The Electric Field

Calculus-Based General Physics

This module beqins the study of electricity. Not only is it true that we see nature's gigantic electrical show in thunderstorm displays with lightning, but the very functioning of our smallest cells depends on the balance of electrically charged ions, and their movement through cell membranes. On a larger scale than cell membranes, water-purification studies with large membranes show promise of "electrically" removing undesired ions or debris from water. The electronic air cleaner is yet another direct application of the material to come: a 7000-V potential difference between a thin wire and flat collecting plates ionizes the air, and the …

Vector Multiplication

Calculus-Based General Physics

How much is A times B? This is a simple question to answer when A and B represent scalars; however, when A and B represent vectors, the answer is not obvious. In fact, on the face of it, one cannot even say whether the result should be a scalar or a vector!

Several different definitions of vector multiplication have been found useful in physics; in this module you will study two types: the scalar and vector products. Just to sharpen your interest, we point out that the vector product has the strange but useful property that A × B = …

Fluid Mechanics

Calculus-Based General Physics

An invigorating shower in the morning is usually a pleasant experience except for the pesky shower curtain slapping your legs and allowing water to run on the floor. You would think that the downward stream of water would be enough to keep the curtain back even without water striking the curtain. But not so: fast-moving fluids (water spray causing a downdraft of air) contain a low-pressure region. Thus the pressure outside the shower is greater than the pressure inside - with the result that the curtain is blown in and flops against your legs.

More technical applications of fluid mechanics …

Planar Motion

Calculus-Based General Physics

Enough of this physics where things move along straight lines only! We know that most interesting real-life motions involve curves of many and varied shapes. This module extends your understanding of kinematics from one dimension to two dimensions. To accomplish this, you will combine your knowledge of calculus and vectors with concepts like position, displacement, velocity, speed, and acceleration.

Two important applications that will be utilized many times in later modules are covered here. First is the motion of a particle experiencing constant acceleration, e.g., a baseball in flight. Second is the motion of a particle in a circular path …