Physics Commons^™

Young's Modulus And Internal Damping In A Vibrating Rod, H. M. Simpson, Paul J. Wolfe

Paul J. Wolfe

A high‐Q mechanical oscillator in the form of a metallic rod with an eddy current driver is described. With this oscillator and a simple crystal transducer the characteristics of a mechanical oscillator can be easily studied and Young’s modulus for the metal can be found. With an inexpensive FM transducer system the internal damping of the metal can also be measured.

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 …

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.

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 …

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.

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. …

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 …

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.

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

Physics Faculty Publications

No abstract provided.

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

Department of Integrated Science and Technology - 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.

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 …

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

Electrical Engineering Faculty Publications

No abstract provided.

Film Thinning In He Ii At Temperatures Above 1.1k, Robert Hallock, E. B. Flint

Robert Hallock

We have made measurements of the velocity-dependent film thinning in saturated films of He II over the temperature range 1.1

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. …

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 …

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

Physics Faculty Publications

No abstract provided.

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, Judith 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.

0 Introduction To Study Modules For Calculus-Based General Physics

Calculus-Based General Physics

These modules were prepared by fifteen college physics professors for use in self-paced, mastery-oriented, student-tutored. calculus-based general physics courses. This style of teaching offers student's a personalized system of instruction (PSI), in which they increase their knowledge of physics and experience a positive learning environment. We hope our efforts in preparing these modules will enable you to try and enjoy teaching physics using PSI.

This is the second printing of the CBP modules. We have tried to remove all of the errors from this material. No doubt, we missed a few, please write to us and tell us any that …

Ampère's Law

Calculus-Based General Physics

Everyone has seen a bar magnet in the form of a compass or a door catch. Anyone who has ever casually played with magnets or magnetic toys knows that magnets interact with other magnets; i.e., a magnet experiences a force caused by thp presence of an external magnetic field produced by the other magnet. A wire carrying a current experiences a force caused by the presence of a nearby magnet (as you saw in the module Magnetic Forces). We then expect the converse to also hold true, i.e., that the bar magnet will also experience a force from the presence …

Diffraction

Calculus-Based General Physics

Have you ever wondered why you can hear around corners, but cannot see around them? You know that light and sound are waves, and should therefore share the same basic properties. Why then do they seem so different in the property of their "shadows"?

In this module you will learn that light does exhibit all the bending properties of sound and water waves. The effect, however, depends on the size of the obstacle compared to the wavelength. It is only the largeness of everyday obstacles compared to the very small wavelength of light that deemphasizes the bending, or diffraction, of …

Electric Potential

Calculus-Based General Physics

You have no doubt noticed that TV sets, light bulbs, and other electric appliances operate on 115 V, but electric ovens and clothes dryers usually need 220 V. Batteries may be rated at a harmless 1.5, 6, 9, or 12 V, but a high-tension electric transmission line may provide electric power at 400,000 V. Now just what physical quantity is measured by all these volts? How do volts relate to force, energy, and power, about which you have learned in earlier modules? The answer is that volts measure electric potential difference (sometimes called "voltage"), which is derived from the potential …

Faraday's Law

Calculus-Based General Physics

Consider the electric light you may be using to read this module by and the influence on your life style of the vast amounts of electrical energy produced in the United States. This module treats the fundamental principle that allows for the transformation of mechanical energy into electrical energy. The physical law that governs the production of electric current is named after its discoverer, Michael Faraday.

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 …

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 …

Lenses And Mirrors

Calculus-Based General Physics

If you have ever worn glasses, used a magnifying glass, looked through a telescope, or looked in a mirror, you have some idea of the effect that transmitting and reflecting materials have on light. When light passes from one material to another it is refracted. It is this property of light that is used in making eye glasses and magnifying glasses. The laws of reflection and refraction have immediate application in the construction of optical instruments. Two main objectives of most optical devices are to increase the light-gathering area and to provide a magnified image. Magnification is not usually the …

Introduction To Quantum Physics

Calculus-Based General Physics

You have probably encountered a system known as an "electric eye," which senses light from an artificial source or the sun. This information is used to open doors, count pedestrian or auto traffic, turn on lights at sunset, read holes in punched card, and for a host of other applications. Most of these devices are based on the photoelectric effect, which is the light-induced emission of electrons from atoms.

The photoelectric effect completely baffled physicists at the time of its discovery. Einstein's explanation of this process, which won the Nobel Prize in 1921, was a major part of the twentieth-century …

Maxwell's Predictions

Calculus-Based General Physics

With this module, you will reach a milestone in your study of electromagnetic phenomena. From past modules, you now have (at your fingertips, hopefully!) the same basic laws of electromagnetism that Maxwell collected together in the nineteenth century. However, as powerful as these laws were, Maxwell found that there was a basic flaw -- a logical inconsistency -- in the one known as Ampere's law. He was able to deduce (in advance of any direct experimental test) precisely the correction that was needed. With this correction, the addition of what is called the "displacement-current" term to Ampere's law, it follows …

Optical Instruments

Calculus-Based General Physics

You are now familiar with some of the properties of idealized single lenses and simple spherical and plane mirrors. Almost all optical instruments are made up of a combination of lenses, some close together and others far apart. Real lenses and mirrors have many undesirable properties intimately interconnected with their desirable properties. By making careful and clever combinations of lenses one can enhance the desirable and minimize the undesirable characteristics. In this module you will begin the study of some simple combinations of mirrors and simple lenses; it will give you some insight into the complications and fascinating possibilities of …

Rectilinear Motion

Calculus-Based General Physics

How long does it take you to go home? This depends on how far you are from home (displacement), how fast (velocity) you can travel, and how often you must start and stop (acceleration).

This module treats kinematics, which is the part of physics concerned with the description of the motion of a body. The body may be an automobile, a baseball, a raindrop, a flower in the wind, or a running horse. The change in position of a body can be described in terms of the vector quantities: displacement, velocity, and acceleration. Calculus can be used to define the …