Browsing by Keywords "Frequencies"
Now showing items 115 of 15

Anharmonicity of zonecenter optical phonons: Raman scattering spectra of GaSe0.5S0.5 layered crystal
(IOPscience, 2002)The temperature dependencies (10300 K) of the eight Ramanactive mode frequencies and linewidths in GaSe0.5S0.5 layered crystal have been measured in the frequency range from 10 to 320 cm1. We observed softening and ... 
Aviation risk perception: a comparison between experts and novices
(WileyBlackwell Publishing, 2004)This article describes an exploratory investigation of the risk perceptions of experts and novices in relation to helicopter operations, under conditions where the participants are matched on various characteristics ... 
Banddropping via coupled photonic crystal waveguides
(Optical Society of American (OSA), 2002)We observe the dropping of electromagnetic waves having a specific frequency or a certain frequency band in twodimensional dielectric photonic crystals. The single frequency is dropped via cavitywaveguide coupling. ... 
Classification of closed and open shell pistachio nuts using principal component analysis of impact acoustics
(2004)An algorithm was developed to separate pistachio nuts with closedshells from those with openshells. It was observed that upon impact on a steel plate, nuts with closedshells emit different sounds than nuts with openshells. ... 
Dynamical correlations in Coulomb drag effect
(Elsevier, 2003)Motivated by recent Coulomb drag experiments in pairs of lowdensity twodimensional (2D) electron gases, we investigate the influence of correlation effects on the interlayer drag rate as a function of temperature. We use ... 
Electromagnetically induced lefthandedness in a dense gas of threelevel atoms
(The American Physical Society, 2004)Ways in which a threelevel system can be used to change the frequencydependent magnetic permeability of an atomic gas were discussed. The resulting macroscopic electrodynamics was also discussed. The two levels were ... 
Highly directional enhanced radiation from sources embedded inside two and threedimensional photonic crystals
(2005)In this work, we have experimentally and theoretically studied the emission of radiation from a monopole source embedded in a two and three dimensional photonic crystal. We have demonstrated the enhancement of radiation ... 
Nano and micro Halleffect sensors for roomtemperature scanning hall probe microscopy
(Elsevier, 2004)GaAs/AlGaAs twodimensional electron gas (GaAs2DEG) Hall probes are impractical for submicron roomtemperature scanning Hall microscopy (RTSHPM), due to surface depletion effects that limit the Hall driving current and ... 
Nonplanar trapezoidal tooth logperiodic antennas: design and electromagnetic modeling
(WileyBlackwell, 2005)Nonplanar trapezoidal tooth logperiodic (LP) antennas are investigated by combining the wisdom of theoretical design procedures with the power of accurate numerical simulation environments. Once the theoretical design is ... 
Perspective projections in the spacefrequency plane and fractional Fourier transforms
(OSA Publishing, 20000706)Perspective projections in the spacefrequency plane are analyzed, and it is shown that under certain conditions they can he approximately modeled in terms of the fractional Fourier transform, The region of validity of the ... 
Phasematched selfdoubling optical parametric oscillator
(Optical Society of America, 19970301)We report a synchronously pumped intracavity frequencydoubled optical parametric oscillator that employs a single KTiOPO4 crystal for both parametric generation and frequency doubling. Both nonlinear processes are phase ... 
Physics and Applications of Defect Structures in Photonic Crystals
(2003)Photonic crystals are three dimensional periodic structures having the property of reflecting the electromagnetic (EM) waves in all dimensions, for a certain range of frequencies. Defects or cavities around the same geometry ... 
Reducedorder modelbased feedback controller design for subsonic cavity flows
(2005)This paper explores feedback controller design for cavity flows based on reducedorder models derived using Proper Orthogonal Decomposition (POD) along with Galerkin projection method. Our preliminary analysis shows that ... 
SU(2)path integral investigation of Holstein dimer
(Elsevier Science Publishers B.V., Amsterdam, Netherlands, 2000)The SU(2) coherent state path integral is used to investigate the partition function of the Holstein dimer. This approach naturally takes into account the symmetry of the model. The groundstate energy and the number of ... 
Subwavelength resolution in a twodimensional photoniccrystalbased superlens
(American Physical Society, 2003)The experimental and theoretical demonstration of a singlebeam negative refraction and a superlensing effect in 2D photonic crystals was reported. As such, negative refraction was observed for the incidence angles of >20°. ...