Open Access. Powered by Scholars. Published by Universities.®

Physics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 3871 - 3900 of 3957

Full-Text Articles in Physics

High Resolution Laser Absorption Spectroscopy Of Ozone Near 1129.4 Cm-1, Lawrence N. Majorana Dec 1980

High Resolution Laser Absorption Spectroscopy Of Ozone Near 1129.4 Cm-1, Lawrence N. Majorana

Physics Theses & Dissertations

A Beer's Law experiment was performed with a tunable laser to determine self broadened line shape parameters of one infrared absorption ozone line in the v1 band for ten pressures from 0.26 to 6.29 Torr at 285K. SO2 line positions were used for wavelength calibration. Line shapes were iteratively fitted to the Voigt function at a Doppler width of 29.54 MHz (HWHM) resulting in values for the integrated line• strength, ( S), of (0.144 +/- 0.007 ) x ·10-20 cm-1/molecule cm-2, line center frequency, (υο) of 1129.426 cm-1 and the Lorentzian contributions to half width, (α …

Go to article

22nd Rocky Mountain Conference On Analytical Chemistry Aug 1980

22nd Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Abstracts and meeting program from the 22nd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 10-14, 1980.

Go to article

An Apparatus For Measuring The Thermal Conductivity Of Cast Insulation Materials, Christine A. Wilkins, Robert L. Ash Jul 1980

An Apparatus For Measuring The Thermal Conductivity Of Cast Insulation Materials, Christine A. Wilkins, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

A steady-state apparatus has been developed for measuring the thermal conductivity of cast materials. The design has employed a novel thermal symmetry arrangement which can permit total electrical isolation of the test material from its surroundings. © 1980 American Institute of Physics

Go to article

Inversion Of The Nonlinear Equations Of Reflection Ellipsometry For Uniaxial Crystals In Symmetrical Orientations, M. Elshazly-Zaghloul, R. M.A. Azzam Jul 1980

Inversion Of The Nonlinear Equations Of Reflection Ellipsometry For Uniaxial Crystals In Symmetrical Orientations, M. Elshazly-Zaghloul, R. M.A. Azzam

Electrical Engineering Faculty Publications

The complex ordinary (No) and extraordinary (Ne) refractive indices of an absorbing uniaxial crystal can be determined using reflection ellipsometry. The measurements are taken with the optic axis parallel and perpendicular to the crystal’s surface. The equations obtained are solved without resort to iterative methods; No and Ne are determined separately. Sixteen solution sets (No, Ne) are obtained and the correct solution can be easily identified. We present an optimum angle of incidence that minimizes the relative errors in No and Ne.

Go to article

Autooscillations And Nonlinear Anelasticity, Manfred Wuttig, Tetsuro Suzuki Jan 1980

Autooscillations And Nonlinear Anelasticity, Manfred Wuttig, Tetsuro Suzuki

Materials Science and Engineering Faculty Research & Creative Works

In conclusion it can be stated that a novel phenomenon, a mechanical auto oscillation, has been described theoretically and shown to exist experimentally. These auto oscillations occur when a nonlinear anelastic solid is forced into large amplitude oscillations in the vicinity of a martensitic transformation. They manifest themselves as a low frequency auto modulation of the a martensitic transformation. They manifest themselves as low frequency auto modulation of the forced vibration of such a solid. © 1980.

Go to article

21st Rocky Mountain Conference On Analytical Chemistry Jul 1979

21st Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Abstracts and meeting program from the 21st annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, July 30 - August 1, 1979.

Go to article

Direct Relation Between Fresnel’S Interface Reflection Coefficients For The Parallel And Perpendicular Polarizations, R. M.A. Azzam Jul 1979

Direct Relation Between Fresnel’S Interface Reflection Coefficients For The Parallel And Perpendicular Polarizations, R. M.A. Azzam

Electrical Engineering Faculty Publications

We have found a significant relation, rp = rs (rs -cos2ϕ)/(1-rs cos2ϕ), between Fresnel’s interface complex-amplitude reflection coefficients rp and rs for the parallel (p) and perpendicular (s) polarizations at the same angle of incidence ϕ. This relation is universal in that it applies to reflection at all interfaces between homogeneous isotropic media collectively and, of course, throughout the electromagnetic spectrum. We investigate the properties of this function, rp = f (rs), and its inverse,rs = g (rp), as …

Go to article

Relations Between Amplitude Reflectances And Phase Shifts Of The P And S Polarizations When Electromagnetic Radiation Strikes Interfaces Between Transparent Media, R. M.A. Azzam Jun 1979

Relations Between Amplitude Reflectances And Phase Shifts Of The P And S Polarizations When Electromagnetic Radiation Strikes Interfaces Between Transparent Media, R. M.A. Azzam

Electrical Engineering Faculty Publications

No abstract provided.

Go to article

Transformation Of Fresnel’S Interface Reflection And Transmission Coefficients Between Normal And Oblique Incidence, R. M.A. Azzam Apr 1979

Transformation Of Fresnel’S Interface Reflection And Transmission Coefficients Between Normal And Oblique Incidence, R. M.A. Azzam

Electrical Engineering Faculty Publications

If w denotes an interface Fresnel reflection or transmission coefficient for s- or p-polarized light at an oblique angle of incidence ø, and z denotes the same coefficient at normal incidence, we find that w is an analytic function of z, w = ƒ(z), that depends on ø but not on the specific optical properties of the two media on both sides of the interface. All four functions that correspond to the four distinct Fresnel coefficients and their inverses are determined. We single out for detailed examination, as an example, the relationship between the reflection of s -polarized light at …

Go to article

Reflection Of An Electromagnetic Plane Wave With 0 Or Π Phase Shift At The Surface Of An Absorbing Medium, R. M.A. Azzam Mar 1979

Reflection Of An Electromagnetic Plane Wave With 0 Or Π Phase Shift At The Surface Of An Absorbing Medium, R. M.A. Azzam

Electrical Engineering Faculty Publications

An electromagnetic plane wave incident obliquely from a transparent medium onto the surface of an absorbing medium can be reflected with 0 or π phase shift if (i) the wave is p (TM) polarized, and (ii) the complex relative dielectric function ε is such that 0 ≤|ε| 2/2Re(ε) ≤ 1. Furthermore, the locus of ε such that the reflection coefficient for the p polarization is real at the same angle of incidence, is a circle, and that of ε½ (the complex relative refractive index) is Bernoulli’s lemniscate.

Go to article

Nonlinear Anelasticity And The Martensitic Transformation, Manfred Wuttig, Tetsuro Suzuki Jan 1979

Nonlinear Anelasticity And The Martensitic Transformation, Manfred Wuttig, Tetsuro Suzuki

Materials Science and Engineering Faculty Research & Creative Works

Zener's model of a standard linear solid is extended to include nonlinearities characteristic of metals and alloys in the vicinity of a martensitic transformation. The equation of motion of a nonlinear anelastic solid is derived and solved using van der Pol's method. The characteristics of the solutions indicate that auto-oscillations of finite amplitude can be excited externally. It is proposed that the streaming oscillations represent the beat between the external excitation and the auto-oscillation. © 1979.

Go to article

Stable Equilibrium Statistical States For Spheromaks, George Vahala, Linda L. Vahala Jan 1979

Stable Equilibrium Statistical States For Spheromaks, George Vahala, Linda L. Vahala

Electrical & Computer Engineering Faculty Publications

Incompressible nondissipative magnetohydrodynamic turbulence is treated for spherical systems. From the absolute equilibrium expectation values of the fields one can investigate those initially quiescent states for which no large mean square velocity will develop. This stable state is force-free and gives rise to the Hill vortex structure for the magnetic flux surfaces.

Go to article

Nucleation Experiments With Monodisperse Nacl Aerosols., Darryl J. Alofs, M. B. Trueblood, D. R. White, V. L. Behr Jan 1979

Nucleation Experiments With Monodisperse Nacl Aerosols., Darryl J. Alofs, M. B. Trueblood, D. R. White, V. L. Behr

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nucleation Experiments with Monodisperse NaCl Aerosols Showed Good Agreement with the Kohler Theory Relating the Critical Super-Saturation S//c to the Dry Size. Aerosols Produced by Condensing NaCl Showed the Same S//c as Those Produced by Evaporating Aqueous NaCl Solution Droplets. This Indicates that If There is an Energy Barrier in Going from a Dry NaCl Particle to a Solution Droplet, This Energy Barrier is Small. the Fact that the Evaporation Aerosol Particles Are Cubical Crystals and the Condensation Aerosols Are Amorphous Spheres is Shown to Make No Difference in the Nucleation Threshold. the Investigation Also Gives Insights into the Performance …

Go to article

Principal Angle, Principal Azimuth, And Principal-Angle Ellipsometry Of Film-Substrate Systems, R. M.A. Azzam, A.-R. M. Zaghloul Dec 1978

Principal Angle, Principal Azimuth, And Principal-Angle Ellipsometry Of Film-Substrate Systems, R. M.A. Azzam, A.-R. M. Zaghloul

Electrical Engineering Faculty Publications

When the film thickness is considered as a parameter, a system composed of a transparent film on an absorbing substrate (in a transparent ambient) is characterized by a range of principal angle ø¯min ≤ ø¯ ≤ ø¯max over which the associated principal azimuth ψ¯ varies between 0° and 90° (i.e., 0° ≤ ψ¯ ≤ 90°) and the reflection phase difference Δ assumes either one of the two values: +π/2 or −π/2. We determine the principal angle ø¯(d) and principal azimuth ψ¯(d) as functions of film thickness d for the vacuum-SiO2-Si system at …

Go to article

Propagation Of Partially Polarized Light Through Anisotropic Media With Or Without Depolarization: A Differential 4 × 4 Matrix Calculus, R. M.A. Azzam Dec 1978

Propagation Of Partially Polarized Light Through Anisotropic Media With Or Without Depolarization: A Differential 4 × 4 Matrix Calculus, R. M.A. Azzam

Electrical Engineering Faculty Publications

We extend the scope of the Mueller calculus to parallel that established by Jones for his calculus. We find that the Stokes vector S of a light beam that propagates through a linear depolarizing anisotropic medium obeys the first-order linear differential equation dS/dz = mS, where z is the distance traveled along the direction of propagation and m is a 4 × 4 real matrix that summarizes the optical properties of the medium which influence the Stokes vector. We determine the differential matrix m for eight basic types of optical behavior, find its form for the most general anisotropic nondepolarizing …

Go to article

Consequences Of Light Reflection At The Interface Between Two Transparent Media Such That The Angle Of Refraction Is 45°, R. M.A. Azzam Nov 1978

Consequences Of Light Reflection At The Interface Between Two Transparent Media Such That The Angle Of Refraction Is 45°, R. M.A. Azzam

Electrical Engineering Faculty Publications

The reflection of light at the interface between two transparent, homogeneous and optically isotropic media such that the angle of refraction is 45° has the following interesting consequences: (i) the interface relfectivity for the parallel (p) polarization is the square of that for the perpendicular (s) polarization; (ii) the angular deviation of the propagation direction upon refraction is equal to the polarization (or ellipsometric) angle ψ and (iii) the complex reflection coefficient for the ppolarization is stationary, in both magnitude and phase, with respect to small charges of the (refractive and/or absorptive) optical properties of …

Go to article

20th Annual Rocky Mountain Conference On Analytical Chemistry Aug 1978

20th Annual Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Abstracts and program from the 20th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 7-9, 1978.

Go to article

Simulation Of Mechanical Rotation By Optical Rotation: Application To The Design Of A New Fourier Photopolarimeter, R. M.A. Azzam Apr 1978

Simulation Of Mechanical Rotation By Optical Rotation: Application To The Design Of A New Fourier Photopolarimeter, R. M.A. Azzam

Electrical Engineering Faculty Publications

The mechanical rotation of an optical element around the axis of a beam of polarized light can be easily simulated by using the phenomenon of optical rotation. Because optical rotation can be magnetically or electrically induced, virtually any kind of mechanical rotation can be mimicked. This interesting principle is applied to the design of a new Fourier photopolarimeter that uses an oscillating-azimuth retarder (OAR). The OAR consists of a quarter-wave plate surrounded by two ac-excited Faraday cells that produce equal and opposite sinusoidal optical rotations. Analysis of the operation of this polarimeter of no moving parts proves its ability to …

Go to article

Generalized Ellipsometry Based On Azimuth Measurements Alone, R. M.A. Azzam Apr 1978

Generalized Ellipsometry Based On Azimuth Measurements Alone, R. M.A. Azzam

Electrical Engineering Faculty Publications

We investigate the azimuth response function, θo = f(θi), of a linear nondepolarizing optical system S, whereθi and θo, are the azimuths (orientations) of the generally elliptic vibrations of totally polarized light at the input and output of S. We find that the azimuth response function depends on five of the six parameters that specify the normalized circular Jones matrix of the optical system. Thus the entire polarization response of an optical system can be nearly completely reconstructed from its azimuth response alone. Five input-output azimuth measurements (θik, θok), k …

Go to article

Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones Jan 1978

Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones

Physics Faculty Research & Creative Works

The cross section for photoionization of potassium atoms in the 4P2 states has been measured in a triple-crossed-beam experiment. © 1978 The American Physical Society.

Go to article

Single-Element Rotating-Polarizer Ellipsometer For Film-Substrate Systems, A.-R. M. Zaghloul, R. M.A. Azzam Sep 1977

Single-Element Rotating-Polarizer Ellipsometer For Film-Substrate Systems, A.-R. M. Zaghloul, R. M.A. Azzam

Electrical Engineering Faculty Publications

A novel and very simple ellipsometer for the characterization of film-substrate systems that employs one rotating optical element (a polarizer) is proposed. The ellipsometer is based on detecting the angles of incidence at which a film-substrate system has equal amplitude attenuations for light polarized parallel (p) and perpendicular (s) to the plane of incidence. At a certain wavelength, the film thickness of the filmsubstrate system has to lie within permissible-thickness bands (PTB) for the technique to apply.

Go to article

19th Annual Conference On Analytical Chemistry Aug 1977

19th Annual Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 19th annual meeting of the Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 1-3, 1977.

Go to article

Static Temperature Measurements In Supersonic Flow Using Lasar Raman Spectroscopy, Paul A. Nystrom Jul 1977

Static Temperature Measurements In Supersonic Flow Using Lasar Raman Spectroscopy, Paul A. Nystrom

Mechanical & Aerospace Engineering Theses & Dissertations

Laser Raman spectroscopy is a nonintrusive technique which can generate mean static temperature (MST) data within flow fields. By ratioing two simultaneously gathered portions of the Raman scattered spectrum, absolute intensity measurements were not needed. This method was applied to a supersonic cold air jet, where the NST ranged from 160'K to 300'K. Accurate measurements were not realized due to the presence of flow contaminates, especially water vapor.

Go to article

Sio2-Si Film-Substrate Reflection Polarizers For Different Mercury Spectral Lines, A.-R. M. Zaghloul, R. M.A. Azzam Jun 1977

Sio2-Si Film-Substrate Reflection Polarizers For Different Mercury Spectral Lines, A.-R. M. Zaghloul, R. M.A. Azzam

Electrical Engineering Faculty Publications

No abstract provided.

Go to article

Effect Of Compliant Wall Motion On Turbulent Boundary Layers, Dennis M. Bushness, Jerry N. Hefner, Robert L. Ash Jan 1977

Effect Of Compliant Wall Motion On Turbulent Boundary Layers, Dennis M. Bushness, Jerry N. Hefner, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

A critical analysis of available compliant wall data which indicated drag reduction under turbulent boundary layers is presented. Detailed structural dynamic calculations suggest that the surfaces responded in a resonant, rather than a compliant, manner. Alternate explanations are given for drag reductions observed in two classes of experiments: (1) flexible pipe flows and (2) water-backed membranes in air. Analysis indicates that the wall motion for the remaining data is typified by short wavelengths in agreement with the requirements of a possible compliant wall drag reduction mechanism recently suggested by Langley. Copyright © 1977 American Institute of Physics.

Go to article

18th Annual Rocky Mountain Spectroscopy Conference Aug 1976

18th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Final program and abstracts from the 18th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 2-3, 1976.

Go to article

Frequency-Mixing Detection (Fmd) Of Polarization-Modulated Light, R. M.A. Azzam Jul 1976

Frequency-Mixing Detection (Fmd) Of Polarization-Modulated Light, R. M.A. Azzam

Electrical Engineering Faculty Publications

When a light beam whose polarization and intensity are weakly modulated at a frequency ωm passes through a periodic analyzer of frequency ωa(<ωm) and the transmitted flux is linearly detected, the resulting total signal St consists of two components: (i) a periodic baseband signal Sbb with harmonics of frequencies nωa (n = 0,1,2,…) and (ii) an amplitude-modulated-carrier signal δSmc with center (carrier) frequency ωm and sideband frequencies at ωm ± nωa(n = 1,2,…). In this paper we show that the average polarization of the beam is determined …

Go to article

Modulated Generalized Ellipsometry, R. M.A. Azzam Jun 1976

Modulated Generalized Ellipsometry, R. M.A. Azzam

Electrical Engineering Faculty Publications

We extend ellipsometry to the direct measurement of small perturbations of the Jones matrix of any linear nondepolarizing optical sample (system) subjected to a modulating stimulus such as temperature, stress, or electric or magnetic field. The methodology of this technique, to be called Modulated Generalized Ellipsometry (MGE), is presented. First an ellipsometer with arbitrary polarizing and analyzing optics is assumed, and subsequently the discussion is specialized to a conventional ellipsometer having either the polarizer-sample-analyzer (PSA) or the polarizer-compensator-sample-analyzer (PCSA) arrangement. MGE provides the tool for the systematic study of thermo-optical, piezo-optical, electro-optical, magneto-optical, and other allied effects for both isotropic …

Go to article

Intermetallic Reactions In Vacuum-Deposited Nickel And Gold Films On (111) Silicon Single Crystals, K. H. Yoon, Gordon Lewis, L. L. Levenson Apr 1976

Intermetallic Reactions In Vacuum-Deposited Nickel And Gold Films On (111) Silicon Single Crystals, K. H. Yoon, Gordon Lewis, L. L. Levenson

Materials Science and Engineering Faculty Research & Creative Works

Pure nickel and gold thin films were vacuum-deposited on (111) silicon single crystals. When Ni/Au/Si or Au/Ni/Si samples were heated to about 550° in situ, hexagonal or deformed hexagonal shaped crystallites were formed on the silicon substrates. The composition of these crystallites was determined by using x-ray diffraction, scanning electron microscopy and scanning Auger microprobe methods. The crystallites were identified as NiSi2. The crystal-lites on the (111) silicon plane parallel to the surface appeared as regular hexagons while the inclined crystal-lites resembled trapezia. The results of Auger spectra and in-depth composition profiles for Ni, Au, and Si showed that the …

Go to article

The Martensite Transformation, Manfred Wuttig, Tetsuro Suzuki Jan 1976

The Martensite Transformation, Manfred Wuttig, Tetsuro Suzuki

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Go to article

First Prev Next Last