Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Astrophysics and Astronomy (15)
- Optics (11)
- Chemistry (8)
- Engineering (8)
- Electrical and Computer Engineering (5)
-
- Other Physics (4)
- Plasma and Beam Physics (4)
- Applied Mathematics (3)
- Mathematics (3)
- Mechanical Engineering (3)
- Quantum Physics (3)
- Atomic, Molecular and Optical Physics (2)
- Electromagnetics and Photonics (2)
- Elementary Particles and Fields and String Theory (2)
- Other Applied Mathematics (2)
- Other Astrophysics and Astronomy (2)
- Algebraic Geometry (1)
- Biological and Chemical Physics (1)
- Computer Engineering (1)
- Computer-Aided Engineering and Design (1)
- Condensed Matter Physics (1)
- Cosmology, Relativity, and Gravity (1)
- Earth Sciences (1)
- Education (1)
- Educational Methods (1)
- Electrical and Electronics (1)
- Environmental Sciences (1)
- Fluid Dynamics (1)
- Institution
-
- University of Nebraska - Lincoln (56)
- Missouri University of Science and Technology (24)
- Syracuse University (15)
- Utah State University (15)
- Wright State University (13)
-
- Claremont Colleges (9)
- Cleveland State University (8)
- University of Massachusetts Amherst (7)
- University of Kentucky (5)
- Bryn Mawr College (4)
- California Polytechnic State University, San Luis Obispo (4)
- Old Dominion University (4)
- Otterbein University (4)
- Brigham Young University (3)
- St. John Fisher University (3)
- The University of San Francisco (3)
- University of New Orleans (3)
- University of South Carolina (3)
- University of Windsor (3)
- William & Mary (3)
- Dartmouth College (2)
- Florida International University (2)
- Nova Southeastern University (2)
- Portland State University (2)
- San Jose State University (2)
- Technological University Dublin (2)
- University of Dayton (2)
- Central Washington University (1)
- College of Saint Benedict and Saint John's University (1)
- Florida Institute of Technology (1)
- Keyword
-
- Condensed matter physics (3)
- Emission Spectra (3)
- Polar cap arcs (3)
- Electromagnetically induced transparency (2)
- Electron temperature (2)
-
- INTERSTELLAR MATTER (2)
- Ionization (2)
- Ionospheric response (2)
- Light-Cone Quantization (2)
- Mathematical models (2)
- Novae (2)
- Photoemission (2)
- Physics, Mechanical, Engineering (2)
- Plasmas (2)
- Population transfer (2)
- Publications (2)
- Radiation Distribution (2)
- Resonance (2)
- Spectra (2)
- Star Formation (2)
- Stellar Envelopes (2)
- Sun-aligned (2)
- Thermodynamics (2)
- Tungsten (2)
- Ultraviolet Astronomy (2)
- Water Masers (2)
- X-ray diffraction (2)
- 2-photon propagation (1)
- AMORPHOUS STATE (1)
- Absorption (1)
- Publication
-
- Physics Faculty Publications (25)
- Physics Faculty Research & Creative Works (18)
- All Physics Faculty Publications (15)
- Physics - All Scholarship (14)
- Faculty Publications (10)
-
- All HMC Faculty Publications and Research (9)
- Peter Dowben Publications (8)
- David Sellmyer Publications (7)
- Physics Department Faculty Publication Series (7)
- Roger Kirby Publications (6)
- Department of Physics and Astronomy: Faculty Publications (5)
- Physics (5)
- Physics and Astronomy Faculty Publications (5)
- Ralph Skomski Publications (5)
- Robert Katz Publications (5)
- Christian Binek Publications (4)
- Physics Faculty Research and Scholarship (4)
- Physics Faculty Scholarship (4)
- Timothy J. Gay Publications (4)
- Arts & Sciences Articles (3)
- Chemistry Faculty Research & Creative Works (3)
- Donald Umstadter Publications (3)
- Opportunities for Undergraduate Research Experience Program (OURE) (3)
- Physics Faculty/Staff Publications (3)
- Physics Publications (3)
- Physics and Astronomy (3)
- Articles (2)
- Chemistry and Physics Faculty Articles (2)
- Dartmouth Scholarship (2)
- FIU Electronic Theses and Dissertations (2)
Articles 1 - 30 of 222
Full-Text Articles in Physics
Formation Of Shape-Preserving Pulses In A Nonlinear Adiabatically Integrable System, R. Grobe, Foek T. Hioe, J. H. Eberly
Formation Of Shape-Preserving Pulses In A Nonlinear Adiabatically Integrable System, R. Grobe, Foek T. Hioe, J. H. Eberly
Physics Faculty/Staff Publications
No abstract provided.
Calculus-Based Physics Exploratory Study: Summary Report, Illinois Mathematics And Science Academy
Calculus-Based Physics Exploratory Study: Summary Report, Illinois Mathematics And Science Academy
Documents
During the 1992-1993 academic year a number of elements (national level surveys and research reports, IMSA’s professional development focus; a climate of reflective inquiry) focused attention on the participation and achievement of females in mathematics and science at a national level and, specifically, the participation and achievement of females in mathematics and science at the Illinois Mathematics and Science Academy. These elements served as the catalyst for the calculus-based physics exploratory study.
Mössbauer Spectroscopic And Magnetic Studies Of Magnetoferritin, Q. A. Pankhurst, S. Betteridge, D. P. E. Dickson, T. Douglas, Stephen Mann, Richard B. Frankel
Mössbauer Spectroscopic And Magnetic Studies Of Magnetoferritin, Q. A. Pankhurst, S. Betteridge, D. P. E. Dickson, T. Douglas, Stephen Mann, Richard B. Frankel
Physics
Mössbauer spectroscopic and magnetic measurements have been made on a novel magnetic protein produced by the controlled reconstitution of ferritin. The data indicate that the predominant mineral form in the iron-containing cores is maghemite (γ-Fe2O3) rather than magnetite (Fe3O4).
Magnetotaxis And Magnetic Particles In Bacteria, Richard B. Frankel, Dennis A. Bazylinski
Magnetotaxis And Magnetic Particles In Bacteria, Richard B. Frankel, Dennis A. Bazylinski
Physics
Magnetotactic bacteria contain magnetic particles that constitute a permanent magnetic dipole and cause each cell to orient and migrate along geomagnetic field lines. Recent results relevant to the biomineralization process and to the function of magnetotaxis are discussed.
Low-Energy Differential Scattering Of Electrons And Positrons From Noble Gases, David D. Reid, J. M. Wadehra
Low-Energy Differential Scattering Of Electrons And Positrons From Noble Gases, David D. Reid, J. M. Wadehra
Physics and Astronomy Faculty Research Publications
Calculations of cross sections for electron (e−) and positron (e+) scattering from ground-state He, Ne, Ar, Kr, and Xe at projectile energies below the lowest inelastic thresholds are presented. The main focus in the present work is on the differential cross sections, since angular distributions depend sensitively on the choice of interaction potentials used in the calculations. A part of the interaction potential used in the calculations includes a parameter-free correlation-polarization potential which is (a) based on physical ideas of what a correlation-polarization potential should be, (b) different for various target gases, and (c) distinct for …
Discrete Symmetries And Isosinglet Quarks In Low-Energy Supersymmetry, Diego Castano, Stephan P. Martin
Discrete Symmetries And Isosinglet Quarks In Low-Energy Supersymmetry, Diego Castano, Stephan P. Martin
Chemistry and Physics Faculty Articles
Many extensions of the minimal supersymmetric standard model contain superfields for quarks which are singlets under weak isospin with electric charge -13. We explore the possibility that such isosinglet quarks have low or intermediate scale masses, but do not mediate rapid proton decay because of a discrete symmetry. By imposing the discrete gauge anomaly cancellation conditions, we show that the simplest way to achieve this is to extend the Z3 “baryon parity” of Ibáñez and Ross to the isosinglet quark superfields. This can be done in three distinct ways. This strategy is not consistent with grand unification with a …
Review Of "Modern Physics From Α To Z°" By J. W. Rohlf, Peter J. Collings
Review Of "Modern Physics From Α To Z°" By J. W. Rohlf, Peter J. Collings
Physics & Astronomy Faculty Works
No abstract provided.
Energy Spread And Ion Current Measurements Of Several Ion Sources, A. D. Gaus, W. T. Htwe, J. A. Brand, Timothy J. Gay, M. Schulz
Energy Spread And Ion Current Measurements Of Several Ion Sources, A. D. Gaus, W. T. Htwe, J. A. Brand, Timothy J. Gay, M. Schulz
Timothy J. Gay Publications
Energy spread and extracted current measurements are presented for five different types of ion sources: hot cathode, cold cathode, magnetron, microwave, and electron cyclotron resonance (ECR). The measurements were performed with a 45° parallel-plate energy analyzer with a resolution of better than 0.5 eV at 500 eV incident energy. Energy spreads ranged from 0.5 to 4 eV, while total extracted beam currents ranged from 2 to 30 μA. Beam currents due specifically to protons, 3He++ ions, and H+2 ions are also presented. The ECR and magnetron sources gave the best overall performance. These, along with the …
Electron-Beam-Induced Patterned Deposition Of Allylcyclopentadienyl Palladium Using Scanning Tunneling Microscopy, D.S. Saulys, A. Ermakov, E.L. Garfunkel, Peter A. Dowben
Electron-Beam-Induced Patterned Deposition Of Allylcyclopentadienyl Palladium Using Scanning Tunneling Microscopy, D.S. Saulys, A. Ermakov, E.L. Garfunkel, Peter A. Dowben
Peter Dowben Publications
Scanning tunneling microscopy has been used to study the electron-induced decomposition of allylcyclopentadienyl palladium [Pd(η3-C3H5)( η5-C5H5)] and subsequent deposition on a Si(111) surface. Deposition occurs via an electron impact mechanism on either the tip or surface, depending on the bias polarity, and is observed with voltages of 2.75 V. This is close to the predicted condensed phase dissociation energy of 2.3 eV for Pd(η3-C3H5)(η5-C5H5)→Pd+C3H5+C5H5. Metallic deposits of nanometer …
Portable, High-Bandwidth Frequency-Domain Photon Migration Instrument For Tissue Spectroscopy, Steen J. Madsen, Eric R. Anderson, Richard C. Haskell, Bruce J. Tromberg
Portable, High-Bandwidth Frequency-Domain Photon Migration Instrument For Tissue Spectroscopy, Steen J. Madsen, Eric R. Anderson, Richard C. Haskell, Bruce J. Tromberg
All HMC Faculty Publications and Research
We describe a novel frequency-domain photon migration instrument employing direct diode laser modulation and avalanche photodiode detection, which is capable of noninvasively determinating the optical properties of biological tissues in near real time. An infinite medium diffusion model was used to extract absorption and transport scattering coefficients from 300-kHz to 800-MHz photon-density wave phase data. Optical properties measured in tissue-simulating solutions at 670 nm agreed to within 10% of those expected.
Small Polarons And The Electronic Properties Of Mo2S3, Adilgiry A. Kusov, Roger D. Kirby
Small Polarons And The Electronic Properties Of Mo2S3, Adilgiry A. Kusov, Roger D. Kirby
Department of Physics and Astronomy: Faculty Publications
We investigate the small-polaron mechanism as a possible explanation of electrical-conduction and electrical-noise properties of the linear chain material Mo2S3. Experimental conductivity and noise data obtained in earlier papers [Phys. Rev. B 38, 3973 (1988); Phys. Rev. B 39, 5139 (1989)] are analyzed in terms of a small-polaron mechanism and double-well potential model. We interpret the observed electronic properties in terms of kinetic equations describing the interaction of free carriers with fluctuations of density of the lattice. Appropriate kinetics equations to describe this interaction, which leads to small-polaron formation, are derived. These equations are found to …
Further Thoughts On Newton's Zero-Order Rainbow, James A. Lock, Timothy A. Mccollum
Further Thoughts On Newton's Zero-Order Rainbow, James A. Lock, Timothy A. Mccollum
Physics Faculty Publications
A zero-order rainbow angle may be defined as the relative minimum angle of deviation of geometrical light rays transmitted without internal reflections through a transparent particle. If the incident rays are parallel and the particle is a sphere, such a minimum does not exist. But if the incident rays ale not parallel or if the particle has an elliptical rather than circular cross section, an angle of minimum deviation, hence a zero-order rainbow, can occur. For a spherical water droplet, the zero-order rainbow will occur when a point source is placed less than a droplet radius away from its surface. …
Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan
Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan
Electro-Optics and Photonics Faculty Publications
In an effort to increase achievable postdetection signal-tonoise ratios (SNRs) of continuous-wave, 1-gm all-solid-state ladar systems, a prototype rare-earth-doped optical-fiber amplifier has been included in the optical return signal path of both a heterodyne and a directdetection ladar system. We provide numerical predictions for SNR increases according to our previously developed theory. We also detail our experimental efforts and provide the results of SNR measurements for four distinct cases: direct ladar detection with and without a fiber amplifier, and heterodyne ladar detection with and without a fiber amplifier. Experimentally measured increases in SNRs for ladar systems incorporating an optical-fiber amplifier …
Improved Frequency Response Measurements In The Human Visual System, Yuping Chen
Improved Frequency Response Measurements In The Human Visual System, Yuping Chen
FIU Electronic Theses and Dissertations
The temporal frequency response characteristics of the human visual system have been investigated by combining the increment threshold and sinusoidal flicker methods. Gain and phase spectra were obtained for two subjects using improved equipment and methodology compared with previous investigations. While the output of the system for sinusoidal input stimuli was generally also sinusoidal, as required for a linear system, other non-linearities emerged. Gain spectra for both subjects indicated a low-pass filtering action. Phase spectra showed a possible low frequency phase lead followed by a high frequency lag. Earlier studies suggested that the system might be a minimum phase system …
Iron Core Formation In Horse Spleen Ferritin: Magnetic Susceptibility, Ph, And Compositional Studies, S. Hilty, B. Webb, Richard B. Frankel, G. D. Watt
Iron Core Formation In Horse Spleen Ferritin: Magnetic Susceptibility, Ph, And Compositional Studies, S. Hilty, B. Webb, Richard B. Frankel, G. D. Watt
Physics
Horse spleen ferritin (HoSF) reconstituted with small iron cores ranging in size from 8 to 500 iron atoms was studied by magnetic susceptibility and pH measurements to determine when the added Fe3+ begins to aggregate and form antiferromagnetically coupled clusters and also to determine the hydrolytic state of the iron at low iron loading. The Evans NMR magnetic susceptibility measurements showed that at iron loadings as low as 8 Fe3+/HoSF, at least half of the added iron atoms were involved in antiferromagnetic exchange interactions and the other half were present as isolated iron atoms with S = …
Deep Defects In Narrow-Gap Semiconductors, Weigang Li, James D. Patterson
Deep Defects In Narrow-Gap Semiconductors, Weigang Li, James D. Patterson
Aerospace, Physics, and Space Science Faculty Publications
We use a Green’s-function technique to calculate the position of deep defects in narrow-gap semiconductors. In order to predict chemical trends, we examine the effects of several different chemical elements. Substitutional (including antisite), (ideal) vacancy, and interstitial (self and foreign) deep defects are considered. The compounds considered are mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS). The effect of relaxation of neighbors is considered for the substitutional and interstitial cases. Relaxation effects can be greater for the interstitial case than for the substitutional one. For all cases we find deep defects in the energy gap …
Aligned Two-Phase Magnets: Permanent Magnetism Of The Future? (Invited), Ralph Skomski
Aligned Two-Phase Magnets: Permanent Magnetism Of The Future? (Invited), Ralph Skomski
Ralph Skomski Publications
Micromagnetic calculations are used to investigate coercivity and energy products of magnets consisting of an aligned hard-magnetic skeleton phase and a soft-magnetic phase with high saturation magnetization. Compared to the present-day theoretical limit of 516 W/m3 for single-phase Nd2Fe14B, the energy product in suitable nanostructured Sm2Fe2N3/Fe65Co35 composites is predicted to be as high as 1090 kJ/m3. The influence of the skeleton’s texture and shape is discussed, and aligned nanocrystalline two-phase magnets are compared with remanence-enhanced isotropic magnets. In particular, it is shown how the nucleation-based analytical …
Mössbauer Study Of Permanent-Magnet Materials: Sm2Fe17-XAlX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer
Mössbauer Study Of Permanent-Magnet Materials: Sm2Fe17-XAlX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer
David Sellmyer Publications
The Fe57 Mössbauer spectra of Sm2Fe17-xAlx, where x=0, 1.0, 2.0, 3.0, and 4.0, have been measured at room temperature and analyzed. The ternary compounds Sm2Fe17-xAlx have the rhombohedral Th2Zn17 structure. Mössbauer measurements showed that all the compounds studied were ferromagnetic. The average hyperfine field was found to decrease with the increasing aluminum concentration, which is in qualitative agreement with magnetic measurements. The decrease in the average hyperfine field was from 224 kOe at x=0 to 174 kOe at x=4. By fitting the …
Sputtering Pressure Effects And Temperature-Dependent Magnetism Of Co/Pd Multilayers, S.Y. Jeong, Z.S. Shan, P. He, J.X. Shen, Y.B. Zhang, John A. Woollam, David J. Sellmyer
Sputtering Pressure Effects And Temperature-Dependent Magnetism Of Co/Pd Multilayers, S.Y. Jeong, Z.S. Shan, P. He, J.X. Shen, Y.B. Zhang, John A. Woollam, David J. Sellmyer
David Sellmyer Publications
The temperature dependence of the sputtering Ar pressure effects on magnetic properties and the coercivity mechanism of Co(2 Å)/Pd(13 Å) multilayers were studied as the sputtering Ar pressure varied from 3–15 mTorr and the temperature from 300 to 35 K. It is found that the roughness of the interfaces or film surface increases with increasing sputtering pressure, the anisotropy increases with decreasing temperature and increasing Ar pressure and shows a maximum at PAr≃12 mTorr, and the coercivity increases with Ar pressure and shows stronger temperature dependence at higher Ar pressure. The coercivity mechanism was analyzed in terms of …
Interface Alloying And Magnetic Properties Of Fe/Rh Multilayers, K. Hanisch, W. Keune, R.A. Brand, Christian Binek, Wolfman Kleemann
Interface Alloying And Magnetic Properties Of Fe/Rh Multilayers, K. Hanisch, W. Keune, R.A. Brand, Christian Binek, Wolfman Kleemann
Christian Binek Publications
Rh(20 Å)/57Fe(tFe) multilayers with Fe thicknesses tFe of 2, 5, 10, and 15 Å prepared by alternate evaporation in UHV have been investigated by x-ray diffraction (XRD), Mössbauer spectroscopy, and SQUID magnetometry. First- and second-order superstructure Bragg peaks (but no higher-order peaks) in small-angle XRD patterns suggest some compositional modulation. Mössbauer spectra taken at 4.2 K are characterized by a distribution P(Bhf) of hyperfine fields Bhf. Peaks observed in the P(Bhf) curves near 17 and 35 T are assigned to an fcc-RhFe interface alloy (~7–24 at. % Fe) with …
Thickness Dependence Of The Magnetic And Electrical Properties Of Fe:Sio2 Nanocomposite Films, S.S. Malhotra, Yi Liu, J.X. Shen, Sy_Hwang Liou, David J. Sellmyer
Thickness Dependence Of The Magnetic And Electrical Properties Of Fe:Sio2 Nanocomposite Films, S.S. Malhotra, Yi Liu, J.X. Shen, Sy_Hwang Liou, David J. Sellmyer
Sy-Hwang Liou Publications
Nanocomposite Fe80 (SiO2)20 films with thickness from 150 to 5000 Å have been prepared by rf magnetron sputtering from a composite target. The crystallites in the Fe80 (SiO2)20 films have a bcc structure with the average size of 46–66 Å which was determined by transmission electron microscopy. As indicated by the thickness dependence of resistivity, the stacking and connectivity of the crystallites depend on the thickness of the films. The magnetic properties also depend on the microstructure which changes with the thickness of the films. The magnetic coercivity of the films increases …
Surface Core-Level Shifts And Atomic Coordination At A Stepped W(110) Surface, D. Mark Riffe, B. Kim, J. L. Erskine, N. D. Shinn
Surface Core-Level Shifts And Atomic Coordination At A Stepped W(110) Surface, D. Mark Riffe, B. Kim, J. L. Erskine, N. D. Shinn
All Physics Faculty Publications
Core-level 4f7/2 photoemission spectra have been measured from a single, bifacial W crystal, which has both a flat W(110) and a vicinal, stepped W(110) [W(320)] surface. This procedure reduces uncertainties in the quantitative description of peaks in the spectra from W(320). Various analyses, including nonlinear least-squares curve fitting, show that the average surface core-level shift (SCS) for W(320) is only ∼-140 meV, compared to -310 meV for W(110) and that, at a maximum, only two of five terrace rows are isoelectronic to W(110) surface atoms. The absence of a large SCS for the step-edge atoms contradicts earlier interpretations of …
Matched Optical Solitary Waves For 3-Level And 5-Level Systems, Foek T. Hioe, R. Grobe
Matched Optical Solitary Waves For 3-Level And 5-Level Systems, Foek T. Hioe, R. Grobe
Physics Faculty/Staff Publications
Exact analytic results are presented that give a general solution for a pair of solitary waves which can propagate through a three- and a five-level system with their shapes invariant. These solitary waves vary widely in shape and form: from ones for which the pulses have similar shape to ones which have very different but ''complementary'' shapes. A general type of solitary-wave pair which is insensitive to small perturbations is identified.
Mössbauer, Magnetic, And Electronic-Structure Studies Of Yfe12-XMoX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer, H.H. Hamdeh
Mössbauer, Magnetic, And Electronic-Structure Studies Of Yfe12-XMoX Compounds, I.A. Al-Omari, Sitaram Jaswal, A.S. Fernando, David J. Sellmyer, H.H. Hamdeh
David Sellmyer Publications
Mössbauer spectra, magnetization measurements, and self-consistent spin-polarized electronic structures of YFe12-xMox, where x=0.5, 1.0, 2.0, 3.0, and 4.0, are reported. The ternary compounds YFe12-xMox have the crystalline tetragonal ThMn12 structure. Analyses of the Mössbauer spectra show that Mo atoms occupy the 8i Fe sites of the ThMn12 structure, in agreement with previous observations. Room-temperature magnetic and Mössbauer measurements show that the compounds with x≤2.0 are ferromagnetic and with x≥3.0 are paramagnetic. Measurements at 25 K show that all the samples are magnetically ordered. The magnetic hyperfine field is …
Three-Body Analytical Potential For Interacting Helium Atoms, Carol A. Parish, Clifford E. Dykstra
Three-Body Analytical Potential For Interacting Helium Atoms, Carol A. Parish, Clifford E. Dykstra
Chemistry Faculty Publications
Large basis set ab initio calculations have been carried out for a dense grid of points on the He, potential energy surface. Three-body contributions were extracted at every point, and a number of concise functional representations for the three-body potential surface were then examined. Three-body multipolar dispersion terms and other radial and angular terms were used in the representations, and an assessment of relative importance of the different terms is presented. Combined with a two-body He-He potential, the results of this work should offer a high quality interaction potential for simulations of aggregated helium.
Cosmological And Wormhole Solutions In Low-Energy Effective String Theory, Mariano Cadoni, Marco Cavaglia
Cosmological And Wormhole Solutions In Low-Energy Effective String Theory, Mariano Cadoni, Marco Cavaglia
Physics Faculty Research & Creative Works
We derive and study a class of cosmological and wormhole solutions of low-energy effective string field theory. We consider a general four-dimensional string effective action where moduli of the compactified manifold and the electromagnetic field are present. The cosmological solutions of the two-dimensional effective theory obtained by dimensional reduction of the former are discussed. In particular we demonstrate that the two-dimensional theory possesses a scale-factor duality invariance. Eucidean four-dimensional instantons describing the nucleation of the baby universes are found and the probability amplitude for the nucleation process given.
Interaction Of A Group Of Dislocations Within The Framework Of The Continuum Frenkel-Kontorova Model, Naum I. Gershenzon
Interaction Of A Group Of Dislocations Within The Framework Of The Continuum Frenkel-Kontorova Model, Naum I. Gershenzon
Physics Faculty Publications
The Frenkel-Kontorova (FK) model of edge dislocation is analyzed. Solutions of the continuum limit of the FK model [the sine-Gordon (SG) equation] are obtained in a form convenient for investigation of dynamics of a large number of interacting dislocations. We consider, based on these solutions, some nonstationary processes: dislocation generation, diffusion of dislocations, and crack-dislocation interaction. Simple relations connecting the velocity of plastic deformation, density and velocity of dislocations, and the force of interaction between dislocations are obtained. The nucleation of dislocations at a moving crack tip is described.
Comment On "Critical Behavior Of The Coulomb Glass", Thomas Vojta, Michael Schreiber
Comment On "Critical Behavior Of The Coulomb Glass", Thomas Vojta, Michael Schreiber
Physics Faculty Research & Creative Works
No abstract provided.
Driven Front And Interface Of A Fluid-Flow Model In 2+1-Dimensions, Michael J. Leaseburg, Ras B. Pandey
Driven Front And Interface Of A Fluid-Flow Model In 2+1-Dimensions, Michael J. Leaseburg, Ras B. Pandey
Faculty Publications
Computer simulations are performed to study the motion of the front and the growth of the interface width in a model of fluid flow driven by a biased field in 2+1 dimensions. The initial motion of the front is diffusive, which is followed by a nondiffusive power-law behavior in the long-time regime; the power-law exponent is nonuniversal, varying with the strength of the driven field. The growth of the interface width saturates in the asymptotic time regime. The saturated width W scales with both the driven field B as well as the transverse length L of the sample, leading to …
A Magnetic, Neutron Diffraction, And Mössbauer Spectral Study Of The Nd₂Fe₁₇₋ₓalₓ Solid Solutions, Gary J. Long, Gaya Kanishka Marasinghe, Sanjay R. Mishra, Oran Allan Pringle, Zhongbo Hu, William B. Yelon, D. P. Middleton, K. H. J. Buschow, Fernande Grandjean
A Magnetic, Neutron Diffraction, And Mössbauer Spectral Study Of The Nd₂Fe₁₇₋ₓalₓ Solid Solutions, Gary J. Long, Gaya Kanishka Marasinghe, Sanjay R. Mishra, Oran Allan Pringle, Zhongbo Hu, William B. Yelon, D. P. Middleton, K. H. J. Buschow, Fernande Grandjean
Chemistry Faculty Research & Creative Works
The magnetic properties of a series of Nd2Fe17-xAlx solid solutions, with x equal to 2.04, 4.01, 5.97, 7.94, and 9.06, have been studied by magnetic measurements, neutron diffraction, and Mössbauer spectroscopy. Magnetization studies indicate that the Curie temperature increases from 330 K in Nd2Fe17 to a maximum of ~470 K at an x of 3.5. The compounds crystallize in the Th2Zn17 structure with lattice parameters and unit cell volumes which increase linearly with increasing aluminum content. The neutron diffraction results indicate that aluminum atoms are excluded from the 9d …