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- Antiferromagnetic materials, ferromagnetic materials, magnetic domains, magnetic hysteresis, magnetic particles, magnetic transitions, magnetostatics, numerical analysis (1)
- Bismuth compounds (1)
- Cobalt compounds (1)
- Composite materials (1)
- Dielectric resonance (1)
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- Electronic specific heat, iron chalcogenide superconductor, multiband superconductivity, magnetic field dependence (1)
- Ferromagnetic resonance (1)
- Field emission electron microscopy (1)
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- Half Heusler, thermoelectric, nanoinclusions, nanomaterial (1)
- Magnetoelectric effects (1)
- Multiferroics (1)
- Scanning electron microscopy (1)
- Sintering (1)
- Sodium compounds (1)
- Statistical spectral estimation, fundamental frequency estimation, statistical signal processing, Fourier transform, autocorrelation, autoregression (1)
- Strontium Ruthenate, amorphous, polycrystalline, semiconducting characteristics, heterostructures, Terfenol-D, Lead Titanate, magnetoelectric coupling (1)
- X-ray diffraction (1)
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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Statistical Spectral Parameter Estimation Of Acoustic Signals With Applications To Byzantine Music, Kyriakos Michael Tsiappoutas
Statistical Spectral Parameter Estimation Of Acoustic Signals With Applications To Byzantine Music, Kyriakos Michael Tsiappoutas
University of New Orleans Theses and Dissertations
Digitized acoustical signals of Byzantine music performed by Iakovos Nafpliotis are used to extract the fundamental frequency of each note of the diatonic scale. These empirical results are then contrasted to the theoretical suggestions and previous empirical findings. Several parametric and non-parametric spectral parameter estimation methods are implemented. These include: (1) Phase vocoder method, (2) McAulay-Quatieri method, (3) Levinson-Durbin algorithm,(4) YIN, (5) Quinn & Fernandes Estimator, (6) Pisarenko Frequency Estimator, (7) MUltiple SIgnal Characterization (MUSIC) algorithm, (8) Periodogram method, (9) Quinn & Fernandes Filtered Periodogram, (10) Rife & Vincent Estimator, and (11) the Fourier transform. Algorithm performance was very precise. …
Circular And Near-Circular Polarization States Of Evanescent Monochromatic Light Fields In Total Internal Reflection, R. M. A Azzam
Circular And Near-Circular Polarization States Of Evanescent Monochromatic Light Fields In Total Internal Reflection, R. M. A Azzam
Electrical Engineering Faculty Publications
Conditions for the production of near-circular polarization states of the evanescent field present in the rarer medium in total internal reflection of incident monochromatic p-polarized light at a dielectric-dielectric planar interface are determined. Such conditions are satisfied if high-index (>3.2) transparent prism materials (e.g., GaP and Ge) are used at angles of incidence well above the critical angle but sufficiently below grazing incidence. Furthermore, elliptical polarization of incident light with nonzero p and s components can be tailored to cause circular polarization of the resultant tangential electric field in the plane of the interface or circular polarization of the …
Poincaré Sphere Representation Of The Fixed-Polarizer Rotating-Retarder Optical System, R. M.A. Azzam
Poincaré Sphere Representation Of The Fixed-Polarizer Rotating-Retarder Optical System, R. M.A. Azzam
Electrical Engineering Faculty Publications
The trajectory of the polarization state of a monochromatic light beam after it passes through a fixed linear polarizer and a rotating linear retarder of arbitrary retardance Δ is determined on the Poincaré sphere. The three-dimensional figure-8 contour is shown to be the line of intersection of a right-circular cylinder with the sphere. The cylinder is parallel to the polar (s3) axis, touches the sphere at the equator (at the point that represents the linear polarization transmitted by the fixed polarizer), and has a radius r=sin2(Δ/2). Projections of the trajectory in the coordinate planes of the …
Three-Dimensional Polarization States Of Monochromatic Light Fields, R. M.A. Azzam
Three-Dimensional Polarization States Of Monochromatic Light Fields, R. M.A. Azzam
Electrical Engineering Faculty Publications
The 3×1 generalized Jones vectors (GJVs) [ExEyEz]t (t indicates the transpose) that describe the linear, circular, and elliptical polarization states of an arbitrary three-dimensional (3-D) monochromatic light field are determined in terms of the geometrical parameters of the 3-D vibration of the time-harmonic electric field. In three dimensions, there are as many distinct linear polarization states as there are points on the surface of a hemisphere, and the number of distinct 3-D circular polarization states equals that of all two-dimensional (2-D) polarization states on the Poincaré sphere, of which only two are circular states. The subset of 3-D polarization …
Thermoelectric Properties Of Zr0.5hf0.5ni1-Xpdxsn0.99sb0.01 And Effect Of Nanoinclusions On Transport Properties Of Half Heuslers, Rumana Yaqub
University of New Orleans Theses and Dissertations
Thermoelectric materials convert temperature gradients into electricity and vice-versa. These materials utilize the Seebeck effect for power generation and function without moving parts and are highly reliable. The efficiency of thermoelectric devices is related to the dimensionless figure of merit for the constituent materials, defined as where S is the Seebeck coefficient, is the electrical conductivity, is the thermal conductivity and T is the temperature. Maximizing ZT is very challenging because of interdependence of parameters, for example, increasing the electrical conductivity by increasing the carrier concentration invariably lowers S and vice versa. Presently numerous thermoelectric materials are being investigated by …
Pulsed Laser Deposition Of Thin Film Heterostructures, Ezra Garza
Pulsed Laser Deposition Of Thin Film Heterostructures, Ezra Garza
University of New Orleans Theses and Dissertations
Thin films of Strontium Ruthenate have been grown on Strontium Titanate and Lanthanum Aluminate (100) substrates by pulsed laser deposition. X-ray diffraction results show that the films grown on the Strontium Titanate are amorphous and polycrystalline on the Lanthanum Aluminate. Resistances versus temperature measurements show that the films exhibit semiconducting characteristics. In addition to the growth of Strontium Ruthenate thin films, multilayer heterostructures of Terfenol-D thin films on polycrystalline Lead Titanate thin films were grown by pulsed laser deposition. By using a novel experimental technique called magnetic field assisted piezoelectric force microscopy it is possible to investigate the magnetoelectric coupling …
Simplified Design Of Thin-Film Polarizing Beam Splitter Using Embedded Symmetric Trilayer Stack, R. M.A. Azzam
Simplified Design Of Thin-Film Polarizing Beam Splitter Using Embedded Symmetric Trilayer Stack, R. M.A. Azzam
Electrical Engineering Faculty Publications
An analytically tractable design procedure is presented for a polarizing beam splitter (PBS) that uses frustrated total internal reflection and optical tunneling by a symmetric LHL trilayer thin-film stack embedded in a high-index prism. Considerable simplification arises when the refractive index of the high-index center layer H matches the refractive index of the prism and its thickness is quarter-wave. This leads to a cube design in which zero reflection for the p polarization is achieved at a 45 degrees angle of incidence independent of the thicknesses of the identical symmetric low-index tunnel layers L and L. Arbitrarily high reflectance for …
Principal Angles And Principal Azimuths Of Frustrated Total Internal Reflection And Optical Tunneling By An Embedded Low-Index Thin Film, R. M.A. Azzam, F. F. Sudradjat
Principal Angles And Principal Azimuths Of Frustrated Total Internal Reflection And Optical Tunneling By An Embedded Low-Index Thin Film, R. M.A. Azzam, F. F. Sudradjat
Electrical Engineering Faculty Publications
The condition for obtaining a differential (or ellipsometric) quarter-wave retardation when p- and s-polarized light of wavelength λ experience frustrated total internal reflection (FTIR) and optical tunneling at angles of incidence ϕ≥ the critical angle by a transparent thin film (medium 1) of low refractive index n1 and uniform thickness d, which is embedded in a transparent bulk medium 0 of high refractive index n0 takes the simple form: −tanh2x=tanδptanδs , in whichx=2πn1(d/λ)(N2sin2ϕ−1)1/2 , N=n0/n1 , and δp , δs are 01 interface Fresnel reflection phase shifts for the pand s polarizations. From this condition, the …
Electric Field Tunable Magnetic Properties Of Lead-Free Na0.5bi0.5tio3/Cofe2o4 Multiferroic Composites, S Narendra Babu, Seong Gi Min, Leszek Malkinski
Electric Field Tunable Magnetic Properties Of Lead-Free Na0.5bi0.5tio3/Cofe2o4 Multiferroic Composites, S Narendra Babu, Seong Gi Min, Leszek Malkinski
Physics Faculty Publications
Lead-free multiferroic particulate composites of Na0.5Bi0.5TiO3 (NBT) and CoFe2O4 (CFO) have been synthesized by solid-state sintering method. A systematic study of structural, magnetic and magnetoelectric (ME) properties is undertaken. Structural and morphology studies carried out by x-ray diffraction and field emission scanning electron microscopy indicate formation of single phase for parent phases and presence of both phases in the composites. Magnetic properties are investigated using vibrating sample magnetometer and ferromagnetic resonance (FMR) measurements at room temperature. Strong ME coupling is demonstrated in NBT-CFO 70-30 mol% composite by an electrostatically tunable FMR field …
Calorimetric Evidence Of Strong-Coupling Multiband Superconductivity In Fe(Te0.57se0.43) Single Crystal, J. Hu, T. J. Liu, B. Qian, A. Rotaru, L. Spinu, Z. Q. Mao
Calorimetric Evidence Of Strong-Coupling Multiband Superconductivity In Fe(Te0.57se0.43) Single Crystal, J. Hu, T. J. Liu, B. Qian, A. Rotaru, L. Spinu, Z. Q. Mao
Physics Faculty Publications
We have investigated the specific heat of optimally doped iron chalcogenide superconductor Fe(Te0.57Se0.43) with a high-quality single crystal sample. The electronic specific heat Ce of this sample has been successfully separated from the phonon contribution using the specific heat of a nonsuperconducting sample (Fe0.90Cu0.10)(Te0.57Se0.43) as a reference. The normal-state Sommerfeld coefficient γn of the superconducting sample is found to be ~26.6 mJ/mol K2, indicating intermediate electronic correlation. The temperature dependence of Ce in the superconducting state can be best fitted using a double-gap …
Thermally Activated Transitions In A System Of Two Single Domain Ferromagnetic Particles, Dorin Cimpoesu, Alexandru Stancu, Ivo Kilk, Ching-Ray Chang, Leonard Spinu
Thermally Activated Transitions In A System Of Two Single Domain Ferromagnetic Particles, Dorin Cimpoesu, Alexandru Stancu, Ivo Kilk, Ching-Ray Chang, Leonard Spinu
Physics Faculty Publications
Numerical simulations based on the stochastic Langevin equation are applied here to a system of two uniaxial single domain ferromagnetic particles with antiferromagnetic dipolar coupling. The hysteresis loops of a strongly coupled systems exhibit fully demagnetized, intermediate metastable configurations which separate the two fully saturated states. At small magnetostatic couplings, on the other hand, and at sufficiently weak damping, the intermediate metastable configuration becomes only partially demagnetized. This state cannot be associated with any single local minimum of the free energy function.