Inpainting using airy diffusion
NASA Astrophysics Data System (ADS)
Lorduy Hernandez, Sara
2015-09-01
One inpainting procedure based on Airy diffusion is proposed, implemented via Maple and applied to some digital images. Airy diffusion is a partial differential equation with spatial derivatives of third order in contrast with the usual diffusion with spatial derivatives of second order. Airy diffusion generates the Airy semigroup in terms of the Airy functions which can be rewritten in terms of Bessel functions. The Airy diffusion can be used to smooth an image with the corresponding noise elimination via convolution. Also the Airy diffusion can be used to erase objects from an image. We build an algorithm using the Maple package ImageTools and such algorithm is tested using some images. Our results using Airy diffusion are compared with the similar results using standard diffusion. We observe that Airy diffusion generates powerful filters for image processing which could be incorporated in the usual packages for image processing such as ImageJ and Photoshop. Also is interesting to consider the possibility to incorporate the Airy filters as applications for smartphones and smart-glasses.
Stationary nonlinear Airy beams
Lotti, A.; Faccio, D.; Couairon, A.; Papazoglou, D. G.; Panagiotopoulos, P.; Tzortzakis, S.; Abdollahpour, D.
2011-08-15
We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.
Voigt Airy surface magneto plasmons.
Hu, Bin; Wang, Qi Jie; Zhang, Ying
2012-09-10
We present a basic theory on Airy surface magneto plasmons (SMPs) at the interface between a dielectric layer and a metal layer (or a doped semiconductor layer) under an external static magnetic field in the Voigt configuration. It is shown that, in the paraxial approximation, the Airy SMPs can propagate along the surface without violating the nondiffracting characteristics, while the ballistic trajectory of the Airy SMPs can be tuned by the applied magnetic field. In addition, the self-deflection-tuning property of the Airy SMPs depends on the direction of the external magnetic field applied, owing to the nonreciprocal effect. PMID:23037243
Bohmian trajectories of Airy packets
NASA Astrophysics Data System (ADS)
Nassar, Antonio B.; Miret-Artés, Salvador
2014-09-01
The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space-time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject's theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.
Bohmian trajectories of Airy packets
Nassar, Antonio B.; Miret-Artés, Salvador
2014-09-15
The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space–time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject’s theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.
Airy beam optical parametric oscillator
NASA Astrophysics Data System (ADS)
Aadhi, A.; Chaitanya, N. Apurv; Jabir, M. V.; Vaity, Pravin; Singh, R. P.; Samanta, G. K.
2016-05-01
Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51–1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond).
Airy beam optical parametric oscillator.
Aadhi, A; Chaitanya, N Apurv; Jabir, M V; Vaity, Pravin; Singh, R P; Samanta, G K
2016-01-01
Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51-1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond). PMID:27143582
Airy beam optical parametric oscillator
Aadhi, A.; Chaitanya, N. Apurv; Jabir, M. V.; Vaity, Pravin; Singh, R. P.; Samanta, G. K.
2016-01-01
Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51–1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond). PMID:27143582
Intensity-symmetric Airy beams.
Vaveliuk, P; Lencina, Alberto; Rodrigo, Jose A; Martnez-Matos, Ó
2015-03-01
Theoretical, numerical, and experimental research on a novel family of Airy beams in rectangular coordinates having a symmetric transverse pattern of light intensity is presented. The intensity-symmetric Airy beams include both the symmetric Airy beam whose field amplitude is an even function of the transverse coordinates and the antisymmetric Airy beam whose field amplitude is an odd function of such coordinates. The theoretical foundations are based on the relationship of the symmetries of the spectral phase with the cosine and sine Fourier transforms. These beams are analyzed in a propagation range also including the region preceding the Fourier plane. These beams exhibit autofocusing, collapse, self-bending, and reversal propagation. Moreover, the intensity distribution is strongly asymmetric with respect to the Fourier plane. All these peculiar features were not reported for other classes of paraxial beams in a rectangular frame. The experimental generation of intensity-symmetric Airy beams is demonstrated supporting the theoretical predictions. Possible applications in planar waveguide writing and optical trapping are also discussed. PMID:26366655
Generation of electron Airy beams.
Voloch-Bloch, Noa; Lereah, Yossi; Lilach, Yigal; Gover, Avraham; Arie, Ady
2013-02-21
Within the framework of quantum mechanics, a unique particle wave packet exists in the form of the Airy function. Its counterintuitive properties are revealed as it propagates in time or space: the quantum probability wave packet preserves its shape despite dispersion or diffraction and propagates along a parabolic caustic trajectory, even though no force is applied. This does not contradict Newton's laws of motion, because the wave packet centroid propagates along a straight line. Nearly 30 years later, this wave packet, known as an accelerating Airy beam, was realized in the optical domain; later it was generalized to an orthogonal and complete family of beams that propagate along parabolic trajectories, as well as to beams that propagate along arbitrary convex trajectories. Here we report the experimental generation and observation of the Airy beams of free electrons. These electron Airy beams were generated by diffraction of electrons through a nanoscale hologram, which imprinted on the electrons' wavefunction a cubic phase modulation in the transverse plane. The highest-intensity lobes of the generated beams indeed followed parabolic trajectories. We directly observed a non-spreading electron wavefunction that self-heals, restoring its original shape after passing an obstacle. This holographic generation of electron Airy beams opens up new avenues for steering electronic wave packets like their photonic counterparts, because the wave packets can be imprinted with arbitrary shapes or trajectories. PMID:23426323
Shen, Ming; Gao, Jinsong; Ge, Lijuan
2015-01-01
We investigate the spatially optical solitons shedding from Airy beams and anomalous interactions of Airy beams in nonlocal nonlinear media by means of direct numerical simulations. Numerical results show that nonlocality has profound effects on the propagation dynamics of the solitons shedding from the Airy beam. It is also shown that the strong nonlocality can support periodic intensity distribution of Airy beams with opposite bending directions. Nonlocality also provides a long-range attractive force between Airy beams, leading to the formation of stable bound states of both in-phase and out-of-phase breathing Airy solitons which always repel in local media. PMID:25900878
Acoustic non-diffracting Airy beam
Lin, Zhou; Guo, Xiasheng Tu, Juan; Ma, Qingyu; Wu, Junru; Zhang, Dong
2015-03-14
The acoustic non-diffracting Airy beam as its optical counterpart has unique features of self-bending and self-healing. The complexity of most current designs handicaps its applications. A simple design of an acoustic source capable of generating multi-frequency and broad-band acoustic Airy beam has been theoretically demonstrated by numerical simulations. In the design, a piston transducer is corrugated to induce spatial phase variation for transducing the Airy function. The piston's surface is grooved in a pattern that the width of each groove corresponds to the half wavelength of Airy function. The resulted frequency characteristics and its dependence on the size of the piston source are also discussed. This simple design may promote the wide applications of acoustic Airy beam particularly in the field of medical ultrasound.
Spatiotemporal dynamics of counterpropagating Airy beams
NASA Astrophysics Data System (ADS)
Wiersma, Noémi; Marsal, Nicolas; Sciamanna, Marc; Wolfersberger, Delphine
2015-08-01
We analyse theoretically the spatiotemporal dynamics of two incoherent counterpropagating Airy beams interacting in a photorefractive crystal under focusing conditions. For a large enough nonlinearity strength the interaction between the two Airy beams leads to light-induced waveguiding. The stability of the waveguide is determined by the crystal length, the nonlinearity strength and the beam’s intensities and is improved when comparing to the situation using Gaussian beams. We further identify the threshold above which the waveguide is no longer static but evolves dynamically either time-periodically or even chaotically. Above the stability threshold, each Airy-soliton moves erratically between privileged output positions that correspond to the spatial positions of the lobes of the counterpropagating Airy beam. These results suggest new ways of creating dynamically varying waveguides, optical logic gates and chaos-based computing.
Spatiotemporal dynamics of counterpropagating Airy beams
Wiersma, Noémi; Marsal, Nicolas; Sciamanna, Marc; Wolfersberger, Delphine
2015-01-01
We analyse theoretically the spatiotemporal dynamics of two incoherent counterpropagating Airy beams interacting in a photorefractive crystal under focusing conditions. For a large enough nonlinearity strength the interaction between the two Airy beams leads to light-induced waveguiding. The stability of the waveguide is determined by the crystal length, the nonlinearity strength and the beam’s intensities and is improved when comparing to the situation using Gaussian beams. We further identify the threshold above which the waveguide is no longer static but evolves dynamically either time-periodically or even chaotically. Above the stability threshold, each Airy-soliton moves erratically between privileged output positions that correspond to the spatial positions of the lobes of the counterpropagating Airy beam. These results suggest new ways of creating dynamically varying waveguides, optical logic gates and chaos-based computing. PMID:26315530
Image signal transmission with Airy beams.
Liang, Yi; Hu, Yi; Song, Daohong; Lou, Cibo; Zhang, Xinzheng; Chen, Zhigang; Xu, Jingjun
2015-12-01
We propose and demonstrate an approach for image signal transmission based on self-accelerating Airy beams. The spatial information is encoded in the Fourier space through a 4-f telescope system, which can circumvent obstacles to realize a self-bending signal transmission. Furthermore, the information can be retrieved from the Airy beams after propagation through a disordered scattering medium. Our experimental results agree well with theoretical predictions. PMID:26625082
Airy-type solitary wave in highly noninstantaneous Kerr media.
Deng, Fu; Hong, Weiyi; Deng, Dongmei
2016-07-11
We investigate the dynamics of a decelerating Airy pulse in the highly noninstantaneous Kerr media. It is found that the deceleration of the Airy pulse can be counteracted by the highly noninstantaneous nonlinearity. When the power of the pulse is specifically chosen, the deceleration of the Airy pulse can be totally restrained, and an Airy-type solitary wave is observed within several dispersion lengths. PMID:27410868
NASA Astrophysics Data System (ADS)
Zhou, Guoquan; Zhang, Lijun; Ru, Guoyun
2015-09-01
As Ai(x)Ai(-x) can be approximated by \\text{exp}≤ft(-{{x}2}/2\\right) , a kind of elegant Hermite-Airy (EHA) beam that is similar to the elegant Hermite-Gaussian (EHG) beam is introduced in this paper. Analytical expression of the EHA beams passing through an ABCD paraxial optical system is derived. By using the method of numerical fitting, the approximate expressions of 02> , 04> , <\\Thetaj2> , <\\Thetaj4> , and 02\\Thetaj2> for an EHA beam are presented, respectively. When the transverse mode number is larger than 2, 02> , 04> , <\\Thetaj2> , <\\Thetaj4> , and 02\\Thetaj2> of an EHA beam are all larger than those of the EHG beam. Based on the higher-order intensity moments, one can calculate the beam propagation factor, the beam half width, and the kurtosis parameter of the EHA beam passing through an ABCD paraxial optical system. As a numerical example, the propagation characteristics of the EHA beam are demonstrated in free space. Moreover, the propagation properties of the EHA beam are compared with those of the corresponding EHG beam. The evolutionary process of the EHA beam is far slower than that of the corresponding EHG beam. The research denotes that the EHA beams can be used to describe specially distributed optical beams that can not be characterized by the existing EHG beam model. The EHA beam model enriches and replenishes the existing beam model.
Ultrafast Airy beam optical parametric oscillator
Apurv Chaitanya, N.; Kumar, S. Chaitanya; Aadhi, A.; Samanta, G. K.; Ebrahim-Zadeh, M.
2016-01-01
We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm. PMID:27476910
Ultrafast Airy beam optical parametric oscillator.
Apurv Chaitanya, N; Kumar, S Chaitanya; Aadhi, A; Samanta, G K; Ebrahim-Zadeh, M
2016-01-01
We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm. PMID:27476910
Ultrafast Airy beam optical parametric oscillator
NASA Astrophysics Data System (ADS)
Apurv Chaitanya, N.; Kumar, S. Chaitanya; Aadhi, A.; Samanta, G. K.; Ebrahim-Zadeh, M.
2016-08-01
We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm.
Temporal Airy pulses control cell poration
NASA Astrophysics Data System (ADS)
Courvoisier, S.; Götte, N.; Zielinski, B.; Winkler, T.; Sarpe, C.; Senftleben, A.; Bonacina, L.; Wolf, J. P.; Baumert, T.
2016-07-01
We show that spectral phase shaping of fs-laser pulses can be used to optimize laser-cell membrane interactions in water environment. The energy and peak intensity thresholds required for cell poration with single pulse in the nJ range can be significantly reduced (25% reduction in energy and 88% reduction in peak intensity) by using temporal Airy pulses, controlled by positive third order dispersion, as compared to bandwidth limited pulses. Temporal Airy pulses are also effective to control the morphology of the induced pores, with prospective applications from cellular to tissue opto-surgery and transfection.
Airy, Sir George Biddell (1801-92)
NASA Astrophysics Data System (ADS)
Murdin, P.
2000-11-01
A brilliant Cambridge mathematician (Senior Wrangler 1823, i.e. leader of the graduating mathematics class), Airy became the seventh Astronomer Royal in 1835 after a brief period as Lucasian Professor at Cambridge. His output was prodigious, and he published nearly 400 scientific papers and 150 reports on various scientific issues, such as the gauge of railways, spectacles to correct astigmatism,...
Creating Airy beams employing a transmissive spatial light modulator.
Latychevskaia, Tatiana; Schachtler, Daniel; Fink, Hans-Werner
2016-08-01
We present a detailed study of two novel methods for shaping the light optical wavefront by employing a transmissive spatial light modulator (SLM). Conventionally, optical Airy beams are created by employing SLMs in the so-called all-phase mode. In the first method, a numerically simulated lens phase distribution is loaded directly onto the SLM, together with the cubic phase distribution. An Airy beam is generated at the focal plane of the numerical lens. We provide for the first time, to the best of our knowledge, quantitative properties of the formed Airy beam. We derive the formula for deflection of the intensity maximum of the so-formed Airy beam, which is different from the quadratic deflection typical of Airy beams. We cross-validate the derived formula by both simulations and experiment. The second method is based on the fact that a system consisting of a transmissive SLM sandwiched between two polarizers can create a transmission function with negative values. This observation alone has the potential for various other wavefront modulations where the transmission function requires negative values. As an example for this method, we demonstrate that a wavefront can be modulated by passing the SLM system with transmission function with negative values by loading an Airy function distribution directly onto the SLM. Since the Airy function is a real-valued function but also with negative values, an Airy beam can be generated by direct transfer of the Airy function distribution onto such an SLM system. In this way, an Airy beam is generated immediately behind the SLM. As both new methods do not employ a physical lens, the two setups are more compact than conventional setups for creating Airy beams. We compare the performance of the two novel methods and the properties of the created Airy beams. PMID:27505393
Accelerating Airy-Gauss-Kummer localized wave packets
NASA Astrophysics Data System (ADS)
Zhong, Wei-Ping; Belić, Milivoj; Zhang, Yiqi; Huang, Tingwen
2014-01-01
A general approach to generating three-dimensional nondiffracting spatiotemporal solutions of the linear Schrödinger equation with an Airy-beam time-dependence is reported. A class of accelerating optical pulses with the structure of Airy-Gauss-Kummer vortex beams is obtained. Our results demonstrate that the optical field contributions to the Airy-Gauss-Kummer accelerating optical wave packets of the cylindrical symmetry can be characterized by the radial and angular mode numbers.
Autobiography of Sir George Biddell Airy
NASA Astrophysics Data System (ADS)
Airy, George Biddell; Airy, Wilfred
2010-06-01
Preface; 1. Personal sketch of George Biddell Airy; 2. From his birth to his taking his B.A. degree; 3. At Trinity College, Cambridge; 4. At Cambridge Observatory; 5. At Greenwich Observatory, 1836-1846; 6. At Greenwich Observatory, 1846-1856; 7. At Greenwich Observatory, 1856-1866; 8. At Greenwich Observatory, 1866-1876; 9. At Greenwich Observatory to his resignation in 1881; 10. At the White House, Greewich, to his death; Appendix: List of printed papers; Index.
The structure of Airy's stress function in multiply connected regions
NASA Technical Reports Server (NTRS)
Grioli, Giusippe
1951-01-01
In solving two-dimensional problems using Airy's stress function for multiply connected regions, the form of the function depends on the dislocations and boundary forces present. The structure of Airy's function is shown to consist of a part expressible in terms of boundary forces and a part expressible in the manner of Poincare. Meanings of the constants occurring in Poincare's expression are discussed.
Propagation Dynamics of Airy Water-Wave Pulses.
Fu, Shenhe; Tsur, Yuval; Zhou, Jianying; Shemer, Lev; Arie, Ady
2015-07-17
We observe the propagation dynamics of surface gravity water waves, having an Airy function envelope, in both the linear and the nonlinear regimes. In the linear regime, the shape of the envelope is preserved while propagating in an 18-m water tank, despite the inherent dispersion of the wave packet. The Airy wave function can propagate at a velocity that is slower (or faster if the Airy envelope is inverted) than the group velocity. Furthermore, the introduction of the Airy wave packet as surface water waves enables the observation of its position-dependent chirp and cubic-phase offset, predicted more than 35 years ago, for the first time. When increasing the envelope of the input Airy pulse, nonlinear effects become dominant, and are manifested by the generation of water-wave solitons. PMID:26230797
Rainbows: Mie computations and the Airy approximation.
Wang, R T; van de Hulst, H C
1991-01-01
Efficient and accurate computation of the scattered intensity pattern by the Mie formulas is now feasible for size parameters up to x = 50,000 at least, which in visual light means spherical drops with diameters up to 6 mm. We present a method for evaluating the Mie coefficients from the ratios between Riccati-Bessel and Neumann functions of successive order. We probe the applicability of the Airy approximation, which we generalize to rainbows of arbitrary p (number of internal reflections = p - 1), by comparing the Mie and Airy intensity patterns. Millimeter size water drops show a match in all details, including the position and intensity of the supernumerary maxima and the polarization. A fairly good match is still seen for drops of 0.1 mm. A small spread in sizes helps to smooth out irrelevant detail. The dark band between the rainbows is used to test more subtle features. We conclude that this band contains not only externally reflected light (p = 0) but also a sizable contribution f rom the p = 6 and p = 7 rainbows, which shift rapidly with wavelength. The higher the refractive index, the closer both theories agree on the first primary rainbow (p = 2) peak for drop diameters as small as 0.02 mm. This may be useful in supporting experimental work. PMID:20581954
Airy structure in 16O+14C nuclear rainbow scattering
NASA Astrophysics Data System (ADS)
Ohkubo, S.; Hirabayashi, Y.
2015-08-01
The Airy structure in 16 O +14 C rainbow scattering is studied with an extended double-folding (EDF) model that describes all the diagonal and off-diagonal coupling potentials derived from the microscopic realistic wave functions for 16 O by using a density-dependent nucleon-nucleon force. The experimental angular distributions at EL=132 , 281, and 382.2 MeV are well reproduced by the calculations. By studying the energy evolution of the Airy structure, the Airy minimum around θ =76∘ in the angular distribution at EL=132 MeV is assigned as the second-order Airy minimum A 2 in contrast to the recent literature which assigns it as the third order A 3 . The Airy minima in the 90∘ excitation function is investigated in comparison with well-known 16 O +16 O and 12 C +12 C systems. Evolution of the Airy structure into the molecular resonances with the 16 O +14 C cluster structure in the low-energy region around Ec .m .=30 MeV is discussed. It is predicted theoretically for the first time for a non-4 N 16O +14 C system that Airy elephants in the 90∘ excitation function are present.
Controllable circular Airy beams via dynamic linear potential
NASA Astrophysics Data System (ADS)
Zhong, Hua; Zhang, Yiqi; Belić, Milivoj R.; Li, Changbiao; Wen, Feng; Zhang, Zhaoyang; Zhang, Yanpeng
2016-04-01
We investigate controllable spatial modulation of circular autofocusing Airy beams, under action of different dynamic linear potentials, both theoretically and numerically. We introduce a novel treatment method in which the circular Airy beam is represented as a superposition of narrow azimuthally-modulated one-dimensional Airy beams that can be analytically treated. The dynamic linear potentials are appropriately designed, so that the autofocusing effect can either be weakened or even eliminated when the linear potential exerts a "pulling" effect on the beam, or if the linear potential exerts a "pushing" effect, the autofocusing effect can be greatly strengthened. Numerical simulations agree with the theoretical results very well.
Accelerating Airy beams in the presence of inhomogeneities
NASA Astrophysics Data System (ADS)
Besieris, Ioannis M.; Shaarawi, Amr M.; Zamboni-Rached, Michel
2016-06-01
Studies have already been made of accelerating Airy beams in the presence of deterministic inhomogeneities, illustrating, in particular, that the inherent self-healing properties of such beams are preserved. The cases of a range-dependent linear transverse potential and a converging GRIN structure (harmonic oscillator) have been examined thoroughly. Examples will be given in this article of novel accelerating Airy beams in the presence of five other types of potential functions. Three of the resulting exact analytical solutions have a common salient characteristic property: they are constructed using the free-space accelerating Airy beam solution as a seed.
Controllable Airy-like beams induced by tunable phase patterns
NASA Astrophysics Data System (ADS)
Li, D.; Qian, Y.
2016-01-01
We propose and experimentally observe a novel family of Airy-like beams. First, we theoretically investigate the physical generation of our proposed controllable Airy-like beams by introducing a rotation angle factor into the phase function, which can regulate and flexibly control the beam wavefront. Meanwhile we can also readily control the main lobes of these beams to follow appointed parabolic trajectories using the rotation angle factor. We also demonstrate that the controllable Airy-like beams lack the properties of being diffraction-free and self-healing. The experiments are performed and the results are in accord with the theoretical simulations. We believe that the intriguing characteristics of our proposed Airy-like beams could provide more degrees of freedom, and are likely to give rise to new applications and lend versatility to the emerging field.
Quasi-Airy beams along tunable propagation trajectories and directions.
Qian, Yixian; Zhang, Site
2016-05-01
We present a theoretical and experimental exhibit that accelerates quasi-Airy beams propagating along arbitrarily appointed parabolic trajectories and directions in free space. We also demonstrate that such quasi-Airy beams can be generated by a tunable phase pattern, where two disturbance factors are introduced. The topological structures of quasi-Airy beams are readily manipulated with tunable phase patterns. Quasi-Airy beams still possess the characteristics of non-diffraction, self-healing to some extent, although they are not the solutions for paraxial wave equation. The experiments show the results are consistent with theoretical predictions. It is believed that the property of propagation along arbitrarily desired parabolic trajectories will provide a broad application in trapping atom and living cell manipulation. PMID:27137563
NASA Astrophysics Data System (ADS)
Chapman, A.
2012-01-01
One major research development in the history of astronomy, pioneered in particular by the SHA, is a shift from the concern with what the ÔgiantsÕ, such as Galileo or Newton, achieved to an examination of the wider spectrum of astronomical personnel. And one rich field of inquiry here is that body of men, and later of women, who earned their livings as assistant astronomers. It is, in fact, an abundantly documented area, including figures employed in Grand Amateur, university, and civic observatories, though without doubt the richest and longest-running body of data pertaining to what might be called the ÔAstronomersÕ GentlemenÕ comes from the archives of the Royal Observatory, Greenwich, especially for the years 1835 to 1881, when Sir George Biddell Airy was Astronomer Royal.
Dynamical deformed Airy beams with arbitrary angles between two wings.
Liang, Yi; Hu, Yi; Ye, Zhuoyi; Song, Daohong; Lou, Cibo; Zhang, Xinzheng; Xu, Jingjun; Morandotti, Roberto; Chen, Zhigang
2014-07-01
We study both numerically and experimentally the acceleration and propagation dynamics of 2D Airy beams with arbitrary initial angles between their "two wings." Our results show that the acceleration of these generalized 2D Airy beams strongly depends on the initial angles and cannot be simply described by the vector superposition principle (except for the normal case of a 90° angle). However, as a result of the "Hyperbolic umbilic" catastrophe (a two-layer caustic), the main lobes of these 2D Airy beams still propagate along parabolic trajectories even though they become highly deformed. Under such conditions, the peak intensity (leading energy flow) of the 2D Airy beams cannot be confined along the main lobe, in contrast to the normal 90° case. Instead, it is found that there are two parabolic trajectories describing the beam propagation: one for the main lobe, and the other for the peak intensity. Both trajectories can be readily controlled by varying the initial wing angle. Due to their self-healing property, these beams tend to evolve into the well-known 1D or 2D Airy patterns after a certain propagation distance. The theoretical analysis corroborates our experimental observations, and explains clearly why the acceleration of deformed Airy beams increases with the opening of the initial wing angle. PMID:25121433
Generation and propagation dynamics of Airy beam with the tunable tail
NASA Astrophysics Data System (ADS)
Liu, Huilong; Lü, Yanfei; Xia, Jing; Pu, Xiaoyun; Zhang, Li
2016-05-01
We introduce a new kind of Airy beam called Airy beam with the tunable tail, which can be generated from the elliptical flat-topped Gaussian beam. The analytical formula of Airy beam with the tunable tail is derived. Airy beam with the single tail can be obtained by adjusting the ration of the beam width of elliptical flat-topped Gaussian beam. The tail length of Airy beam can be controlled by the order N of incident beam. The normalized intensity distributions of Airy beam with the tunable tail propagating in free space are studied, and the propagation dynamics of Airy beam with the single tail are investigated. Compared with the Airy beam generated from the fundamental Gaussian beam or the flat-topped Gaussian beam, some interesting and useful information has been found.
75 FR 43816 - Amendment of Class E Airspace; Mount Airy, NC
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-27
...This action amends Class E Airspace at Mount Airy, NC, to accommodate the additional airspace needed for the Standard Instrument Approach Procedures (SIAPs) developed for Mount Airy-Surry County...
Vessel extraction using the Buckmaster-Airy filter
NASA Astrophysics Data System (ADS)
Sanchez, Valentina
2016-05-01
A new and powerful technique for vessel extraction from biomedical images using the so called Buckmaster- Airy Filter is designed, prototyped and tested. The design, the prototyping and the testing were performed using computer algebra software, specifically the Maple package ImageTools. Some preliminary experiments were performed ant the results were excellent. Our new technique is based on partial differential equations.. Specifically two dimensional Airy diffusion equation and the two dimensional Buckmaster equation were used for designing the new Buckmaster-Airy Filter. Such new filter is able to enhance the quality of an image, producing simultaneously noise elimination, but without altering the edges of the image. The new Bukmaster-Airy filter is applied to the target image via discrete convolution. The results of some experiments of vessel extraction will be presented; and some lines for future research such as the possible implementation of the Buckmaster-Airy Filter as a new plugging for the program ImageJ, will be proposed.
Optical trapping and manipulation of Mie particles with Airy beam
NASA Astrophysics Data System (ADS)
Zhao, Ziyu; Zang, Weiping; Tian, Jianguo
2016-02-01
In this paper we calculate the radiation forces and moving trajectories of Mie particles induced by 1D Airy beams using the plane wave spectrum method and arbitrary beam theory. Numerical results show that both the transverse and the longitudinal radiation forces are deeply dependent on the relative refractive index, radii and positions of the scattering particles illuminated by the Airy beam. Due to the radiation forces, Mie particles with different radii and initial positions can be dragged into the nearest main intensity lobes, and move along parabolic trajectories in the direction of the Poynting vector. At the ends of these trajectories, in the presence of Brownian force, the trapped scattering particles show irregular Brownian movement near their equilibrium positions. This characteristic property of Airy beams enables optical sorting to be used more easily in the colloidal and biological sciences.
Airy-Kaup-Kupershmidt filters applied to digital image processing
NASA Astrophysics Data System (ADS)
Hoyos Yepes, Laura Cristina
2015-09-01
The Kaup-Kupershmidt operator is applied to the two-dimensional solution of the Airy-diffusion equation and the resulting filter is applied via convolution to image processing. The full procedure is implemented using Maple code with the package ImageTools. Some experiments were performed using a wide category of images including biomedical images generated by magnetic resonance, computarized axial tomography, positron emission tomography, infrared and photon diffusion. The Airy-Kaup-Kupershmidt filter can be used as a powerful edge detector and as powerful enhancement tool in image processing. It is expected that the Airy-Kaup-Kupershmidt could be incorporated in standard programs for image processing such as ImageJ.
Improved Intrapulse Raman Scattering Control via Asymmetric Airy Pulses
NASA Astrophysics Data System (ADS)
Hu, Yi; Tehranchi, Amirhossein; Wabnitz, Stefan; Kashyap, Raman; Chen, Zhigang; Morandotti, Roberto
2015-02-01
We experimentally demonstrate the possibility of tuning the frequency of a laser pulse via the use of an Airy pulse-seeded soliton self-frequency shift. The intrinsically asymmetric nature of Airy pulses, typically featured by either leading or trailing oscillatory tails (relatively to the main lobe), is revealed through the nonlinear generation of both a primary and a secondary Raman soliton self-frequency shift, a phenomenon which is driven by the soliton fission processes. The resulting frequency shift can be carefully controlled by using time-reversed Airy pulses or, alternatively, by applying an offset to the cubic phase modulation used to generate the pulses. When compared with the use of conventional chirped Gaussian pulses, our technique brings about unique advantages in terms of both efficient frequency tuning and feasibility, along with the generation and control of multicolor Raman solitons with enhanced tunability. Our theoretical analysis agrees well with our experimental observations.
Super-resolution imaging based on virtual Airy spot
NASA Astrophysics Data System (ADS)
Liu, Zhengjun; Guo, Cheng; Cui, Junning; Wu, Qun
2015-02-01
Based on the theoretical model of Airy spot, a method is proposed for improving the imaging speed from confocal microscopy. The virtual Airy spot is designed for obtaining the pattern on CCD at detecting plane. Here the size of the spot is determined by the parameters of imaging system and intensity data from point detector, which can receive data quicker than CCD. The treatment can improve the speed of imaging comparing with CCD at receiving end. The virtual structured detection is also utilized for generating high-resolution image. Some numerical simulation results are provided for demonstrating the validity of the proposed method.
Photorefractive and computational holography in the experimental generation of Airy beams
NASA Astrophysics Data System (ADS)
Suarez, Rafael A. B.; Vieira, Tarcio A.; Yepes, Indira S. V.; Gesualdi, Marcos R. R.
2016-05-01
In this paper, we present the experimental generation of Airy beams via computational and photorefractive holography. Experimental generation of Airy beams using conventional optical components presents several difficulties and a practically infeasible. Thus, the optical generation of Airy beams has been made from the optical reconstruction of a computer generated hologram implemented by a spatial light modulator. In the photorefractive holography technique, being used for the first time to our knowledge, the hologram of an Airy beam is constructed (recorded) and reconstructed (read) optically in a nonlinear photorefractive medium. The Airy beam experimental realization was made by a setup of computational and photorefractive holography using a photorefractive Bi12 TiO20 crystal as holographic recording medium. Airy beams and Airy beam arrays were obtained experimentally in accordance with the predicted theory; with excellent prospects for applications in optical trapping and optical communications systems.
Experimental observation and analysis of all-fiber plasmonic double Airy beams.
Guan, Chunying; Ding, Ming; Shi, Jinhui; Hua, Ping; Wang, Pengfei; Yuan, Libo; Brambilla, Gilberto
2014-07-28
The propagation dynamics of all-fiber plasmonic double parallel and orthogonal Airy beams are experimentally demonstrated. Two slits and groove arrays were fabricated by focused ion beam (FIB) milling on the gold coated end facet of an optical fiber to generate two Airy beams simultaneously. Sub-wavelength self-focusing of double parallel Airy beams in free space is experimentally verified. Effects of geometrical parameters on the intensity profiles of the focal spot are analyzed in detail. The characteristics at the junction of the two main lobes can be adjusted by controlling the initial phase difference of the two Airy beams. The propagation of two orthogonal Airy beams is also experimentally investigated. Multi-Airy beams are of importance to realize all-fiber optical trapping, fiber integrated devices, and laser shaping. PMID:25089455
Propagation of Airy Gaussian vortex beams in uniaxial crystals
NASA Astrophysics Data System (ADS)
Weihao, Yu; Ruihuang, Zhao; Fu, Deng; Jiayao, Huang; Chidao, Chen; Xiangbo, Yang; Yanping, Zhao; Dongmei, Deng
2016-04-01
The propagation dynamics of the Airy Gaussian vortex beams in uniaxial crystals orthogonal to the optical axis has been investigated analytically and numerically. The propagation expression of the beams has been obtained. The propagation features of the Airy Gaussian vortex beams are shown with changes of the distribution factor and the ratio of the extraordinary refractive index to the ordinary refractive index. The correlations between the ratio and the maximum intensity value during the propagation, and its appearing distance have been investigated. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374108, 11374107, 10904041, and 11547212), the Foundation of Cultivating Outstanding Young Scholars of Guangdong Province, China, the CAS Key Laboratory of Geospace Environment, University of Science and Technology of China, the National Training Program of Innovation and Entrepreneurship for Undergraduates (Grant No. 2015093), and the Science and Technology Projects of Guangdong Province, China (Grant No. 2013B031800011).
Multi-focus of modulated polarized Airy beam
NASA Astrophysics Data System (ADS)
Zhao, Hongyang; Lin, Jie; Tan, Jiubin; Jin, Peng
2016-07-01
The focusing performance of a modulated polarized Airy beam is explored by using the Richards and Wolf vectorial diffraction model in a high numerical aperture system. The multiple foca appeared on the focal plane or along the optical axis when a complex amplitude modulating function was introduced. Two focusing spots with long-focal-depth were additionally observed due to the Airy beam and complex amplitude modulation. The distance between the focuses were changed from 1.15λ to 3.56λ with FWHM of 0.9λ for one-dimensional linear polarized incident beam and from 1.15λ to 3.64λ for two-dimensional beam. The multiple focusing spots are expected to apply in the field of optical trapping and particle acceleration.
Propagation of time-truncated Airy-type pulses in media with quadratic and cubic dispersion.
Borda-Hernández, José A; Zamboni-Rached, Michel; Shaarawi, Amr; Besieris, Ioannis M
2015-10-01
In this paper, we describe analytically the propagation of Airy-type pulses truncated by a finite-time aperture when second- and third-order dispersion effects are considered. The mathematical method presented here, which is based on the superposition of exponentially truncated Airy pulses, is very effective and allows us to avoid the use of time-consuming numerical simulations. We analyze the behavior of the time-truncated ideal Airy pulse and also the interesting case of a time-truncated Airy pulse with a "defect" in its initial profile, which reveals the self-healing property of this kind of pulse solution. PMID:26479932
75 FR 14381 - Amendment of Class E Airspace; Mount Airy, NC
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-25
...This action proposes to amend Class E Airspace at Mount Airy, NC, to accommodate the additional airspace needed for the Standard Instrument Approach Procedures (SIAPs) developed for Mount Airy-Surry County Airport. This action enhances the safety and airspace management of Instrument Flight Rules (IFR) operations at the...
Analytical study of the self-healing property of Airy beams
NASA Astrophysics Data System (ADS)
Chu, Xiuxiang; Zhou, Guoquan; Chen, Ruipin
2012-01-01
An analytical expression for the optical field of an Airy beam partially blocked by an opaque obstacle is derived. The self-healing properties of the Airy beam are studied and discussed in detail. The study shows that the self-healing process of the Airy beam is affected by many factors such as the opaque obstacle size, propagation distance, wavelength, and parameters of the Airy beam. The self-healing process is caused by the convergence of energy from the side to the position of the opaque obstacle and is finished when the convergence of energy flow disappears. When the propagation distance is short, the main lobe of the Airy beam is affected by the obstruction located near the main lobe. When the propagation distance is long, the main lobe of the Airy beam can be affected by the obstruction located far away from the main lobe. The result agrees with the existing results and can be explained by the caustic of the Airy beam.
Quantum polarization fluctuations of an Airy beam in turbulent atmosphere in a slant path.
Yin, Xia; Zhang, Licheng
2016-07-01
Polarization of light has many applications in quantum information processing, including quantum teleportation and dense coding. In this paper, we investigate the polarization fluctuations of Airy beams propagating in a slant turbulent channel under the "few-photon" limit. Using the quantum Stokes parameters and the quantum degree of polarization, we demonstrate that the degree of polarization of Airy beams increases significantly with the large number of the detection photons, and a higher photon-number level can retain the stability of polarization. Numerical simulations show that the longer propagation distance and the stronger turbulence will lead to less oscillatory behaviors and a decrease in the polarization degree of Airy beams, but a bigger exponential truncation factor will cause an increase in the polarization degree of Airy beams. In contrast with Gaussian beams, the degree of polarization of Airy beams is less affected by atmospheric turbulence and propagation distance under the same conditions, which means that Airy beams possess a resilient ability against turbulence-induced perturbations. These results indicate that Airy beams have great potential for applications in long-distance free-space optical communications to improve the performance of a polarization-encoded free-space quantum communication system. PMID:27409692
Generalized Airy functions for use in one-dimensional quantum mechanical problems
NASA Technical Reports Server (NTRS)
Eaves, J. O.
1972-01-01
The solution of the one dimensional, time independent, Schroedinger equation in which the energy minus the potential varies as the nth power of the distance is obtained from proper linear combinations of Bessel functions. The linear combinations called generalized Airy functions, reduce to the usual Airy functions Ai(x) and Bi(x) when n equals 1 and have the same type of simple asymptotic behavior. Expressions for the generalized Airy functions which can be evaluated by the method of generalized Gaussian quadrature are obtained.
Control on the anomalous interactions of Airy beams in nematic liquid crystals.
Shen, Ming; Li, Wei; Lee, Ray-Kuang
2016-04-18
We reveal a controllable manipulation of anomalous interactions between Airy beams in nonlocal nematic liquid crystals numerically. With the help of an in-phase fundamental Gaussian beam, attraction between in-phase Airy beams can be suppressed or become a repulsive one to each other; whereas the attraction can be strengthened when the Gaussian beam is out-of-phase. In contrast to the repulsive interaction in local media, stationary bound states of breathing Airy soliton pairs are found in nematic liquid crystals. PMID:27137288
AIRY: a complete tool for the simulation and the reconstruction of astronomical images
NASA Astrophysics Data System (ADS)
La Camera, Andrea; Carbillet, Marcel; Olivieri, Chiara; Boccacci, Patrizia; Bertero, Mario
2012-07-01
The Software Package AIRY (acronym for Astronomical Image Restoration in interferometrY) is a software tool designed to perform simulation and/or deconvolution of images of Fizeau interferometers as well as of any kind of optical telescopes. AIRY is written in IDL and is a Software Package of the CADS Problem Solving Environment (PSE): it is made of a set of modules, each one representing a specific task. We present here the last version of the software, arrived at its sixth release after 10 years of development. This version of AIRY summarizes the work done in recent years by our group, both on AIRY and on AIRY-LN, the version of the software dedicated to the image restoration of LINC-NIRVANA (LN), the Fizeau interferometer of the Large Binocular Telescope (LBT). AIRY v.6.0 includes a renewed deconvolution module implementing regularizations, accelerations, and stopping criteria of standard algorithms, such as OSEM and Richardson-Lucy. Several modules of AIRY have been improved and, in particular, the one used for the extraction and extrapolatioThe Software Package AIRY (acronym for Astronomical Image Restoration in interferometrY) is a software tool designed to perform simulation and/or deconvolution of images of Fizeau interferometers as well as of any kind of optical telescopes. AIRY is written in IDL and is a Software Package of the CAOS Problem Solving Environment (PSE): it is made of a set of modules, each one representing a speci_c task. We present here the last version of the software, arrived at its sixth release after 10 years of development. This version of AIRY summarizes the work done in recent years by our group, both on AIRY and on AIRY-LN, the version of the software dedicated to the image restoration of LINC-NIRVANA (LN), the Fizeau interferometer of the Large Binocular Telescope (LBT). AIRY v.6.0 includes a renewed deconvolution module implementing regularizations, accelerations, and stopping criteria of standard algorithms, such as OSEM and
Guiding ultraslow weak-light bullets with Airy beams in a coherent atomic system
NASA Astrophysics Data System (ADS)
Hang, Chao; Huang, Guoxiang
2014-01-01
We investigate the possibility of guiding stable ultraslow weak-light bullets by using Airy beams in a cold, lifetime-broadened four-level atomic system via electromagnetically induced transparency (EIT). We show that under EIT condition the light bullet with ultraslow propagating velocity and extremely low generation power formed by the balance between diffraction and nonlinearity in the probe field can be not only stabilized but also steered by the assisted field. In particular, when the assisted field is taken to be an Airy beam, the light bullet can be trapped into the main lobe of the Airy beam, propagate ultraslowly in longitudinal direction, accelerate in transverse directions, and move along a parabolic trajectory. We further show that the light bullet can bypass an obstacle when guided by two sequential Airy beams. A technique for generating ultraslow helical weak-light bullets is also proposed.
NASA Technical Reports Server (NTRS)
Constantinides, E. D.; Marhefka, R. J.
1992-01-01
The incomplete Airy integrals serve as canonical functions for the uniform ray optical solutions to several high frequency scattering and diffraction problems that involve a class of integrals characterized by two stationary points that are arbitrarily close to one another or to an integration endpoint. Integrals of such analytical properties describe transition region phenomena associated with composite shadow boundaries. An efficient and accurate method for computing the incomplete Airy functions would make the solutions to such problems useful for engineering purposes. Here, a convergent series solution form for the incomplete Airy functions is derived. Asymptotic expansions involving several terms were also developed and serve as large argument approximations. The combination of the series solution form with the asymptotic formulae provides for an efficient and accurate computation of the incomplete Airy functions. Validation of accuracy is accomplished using direct numerical integration data.
Quantitative comparison of self-healing ability between Bessel–Gaussian beam and Airy beam
Wen, Wei; Chu, Xiuxiang
2015-09-15
The self-healing ability during propagation process is one of the most important properties of non-diffracting beams. This ability has crucial advantages to light sheet-based microscopy to reduce scattering artefacts, increase the quality of the image and enhance the resolution of microscopy. Based on similarity between two infinite-dimensional complex vectors in Hilbert space, the ability to a Bessel–Gaussian beam and an Airy beam have been studied and compared. Comparing the evolution of the similarity of Bessel–Gaussian beam with Airy beam under the same conditions, we find that Bessel–Gaussian beam has stronger self-healing ability and is more stable than that of Airy beam. To confirm this result, the intensity profiles of Bessel–Gaussian beam and Airy beam with different similarities are numerically calculated and compared.
Propagation of Airy-Gaussian beams in a chiral medium
NASA Astrophysics Data System (ADS)
Deng, Fu; Yu, Weihao; Huang, Jiayao; Zhao, Ruihuang; Lin, Jiong; Deng, Dongmei
2016-04-01
We have expressed and investigated the propagation of Airy-Gaussian beams (AiGBs) in a chiral medium analytically. It is shown that AiGBs split into two components, i.e., the left circularly polarized (LCP) beams and the right circularly polarized (RCP) beams, which have a different propagation trajectory and are affected by the chiral parameter γ and the distribution factor χ0. It is found that the LCP beams accelerate faster than the RCP beams during propagation, and are influenced by the chiral parameter. With an increase in the chiral parameter, the acceleration of the LCP beams increases, but that of the RCP beams decreases. So, it is significant that we can control the self-acceleration of AiGBs by varying the chiral parameter and the distribution factor.
Interaction of Airy-Gaussian beams in Kerr media
NASA Astrophysics Data System (ADS)
Peng, Yulian; Peng, Xi; Chen, Bo; Zhou, Meiling; Chen, Chidao; Deng, Dongmei
2016-01-01
We study the interaction of the Airy-Gaussian (AiG) beams by using the numerical simulations with the split-step Fourier method. The results show that the single breathers and breather pairs can be formed in the condition with interaction. The breathers can be formed with the enough intensity of interactive beams. By adjusting the parameters of amplitude, interval, phase and χ0, we find that the interaction of the two beams is the strongest with in-phase and out-of-phase cases, especially in the shorter distance. Moreover, both the interaction intensity and the location, the interaction happens, can be changed by adjusting the distribution factor χ0 of the beams. It is notable that the various propagation directions of the beams can be obtained by changing the phase, at the same situation, when the interval of the two beams becomes narrower, the phase plays an important role of controlling the direction of the accelerated spot.
Wei, Bing-Yan; Chen, Peng; Hu, Wei; Ji, Wei; Zheng, Li-Yang; Ge, Shi-Jun; Ming, Yang; Chigrinov, Vladimir; Lu, Yan-Qing
2015-01-01
Researches on Airy beams have grown explosively since the first demonstration in 2007 due to the distinguishing properties of nondiffraction, transverse acceleration and self-healing. To date, a simple and compact approach for generating Airy beams in high quality and efficiency has remained challenging. Here, we propose and demonstrate a liquid crystal (LC) polarization Airy mask (PAM) featured by spatially variant LC azimuthal director. The PAM is fabricated through photoaligning LC via a polarization-sensitive alignment agent suophonic azo dye SD1. Thanks to the special design, a novel feature of polarization-controllable switch between dual Airy beams of orthogonal circular polarization is presented. The molecular-level continuity of LC director significantly improves the quality and efficiency of resultant Airy beams. Besides, the PAM can handle intense light due to the absence of absorptive electrodes. Additional merits of compact size, low cost and broad wavelength tolerance are also exhibited. This work settles a fundamental requirement for Airy beam applications of optical manipulations, biology science and even some uncharted territories. PMID:26626737
Wei, Bing-Yan; Chen, Peng; Hu, Wei; Ji, Wei; Zheng, Li-Yang; Ge, Shi-Jun; Ming, Yang; Chigrinov, Vladimir; Lu, Yan-Qing
2015-01-01
Researches on Airy beams have grown explosively since the first demonstration in 2007 due to the distinguishing properties of nondiffraction, transverse acceleration and self-healing. To date, a simple and compact approach for generating Airy beams in high quality and efficiency has remained challenging. Here, we propose and demonstrate a liquid crystal (LC) polarization Airy mask (PAM) featured by spatially variant LC azimuthal director. The PAM is fabricated through photoaligning LC via a polarization-sensitive alignment agent suophonic azo dye SD1. Thanks to the special design, a novel feature of polarization-controllable switch between dual Airy beams of orthogonal circular polarization is presented. The molecular-level continuity of LC director significantly improves the quality and efficiency of resultant Airy beams. Besides, the PAM can handle intense light due to the absence of absorptive electrodes. Additional merits of compact size, low cost and broad wavelength tolerance are also exhibited. This work settles a fundamental requirement for Airy beam applications of optical manipulations, biology science and even some uncharted territories. PMID:26626737
NASA Astrophysics Data System (ADS)
Wei, Bing-Yan; Chen, Peng; Hu, Wei; Ji, Wei; Zheng, Li-Yang; Ge, Shi-Jun; Ming, Yang; Chigrinov, Vladimir; Lu, Yan-Qing
2015-12-01
Researches on Airy beams have grown explosively since the first demonstration in 2007 due to the distinguishing properties of nondiffraction, transverse acceleration and self-healing. To date, a simple and compact approach for generating Airy beams in high quality and efficiency has remained challenging. Here, we propose and demonstrate a liquid crystal (LC) polarization Airy mask (PAM) featured by spatially variant LC azimuthal director. The PAM is fabricated through photoaligning LC via a polarization-sensitive alignment agent suophonic azo dye SD1. Thanks to the special design, a novel feature of polarization-controllable switch between dual Airy beams of orthogonal circular polarization is presented. The molecular-level continuity of LC director significantly improves the quality and efficiency of resultant Airy beams. Besides, the PAM can handle intense light due to the absence of absorptive electrodes. Additional merits of compact size, low cost and broad wavelength tolerance are also exhibited. This work settles a fundamental requirement for Airy beam applications of optical manipulations, biology science and even some uncharted territories.
NASA Astrophysics Data System (ADS)
Yang, Yang; Xue, Yanli; Li, Jiafang; Li, Zhi-Yuan
2016-08-01
In this paper, using an angular spectrum method, we develop an analytical theory for Airy surface plasmon wave excited in a classical Kretschmann setup. It is found that the center of an Airy surface plasmon polariton (SPP) wave has a giant positive lateral shift, and the sidelobes move forward along the surface. The intensity of the Airy SPP wave is greatly enhanced, the corresponding optical forces can be enhanced by more than one order of magnitude. Importantly, we show that the sidelobes of the Airy SPP beam can lead to the splitting of optical force spectra with the variation of incident angle, which is accompanied by strong oscillations emerging at the optimal metal layer thickness. Moreover, the effects of multiple scatterings of the Airy SPP wave between the particle and the metal layer are also discussed. The theoretical analysis could open up new perspectives for the applications of Airy beam in optical manipulation and surface-enhanced Raman scattering.
Evolution of the ring Airy Gaussian beams with a spiral phase in the Kerr medium
NASA Astrophysics Data System (ADS)
Chen, Bo; Chen, Chidao; Peng, Xi; Peng, Yulian; Zhou, Meiling; Deng, Dongmei; Guo, Hong
2016-05-01
Nonlinear optical phenomena are of great practical interest in optics. The evolution of ring Airy Gaussian beams with a spiral phase in the nonlinear Kerr medium is investigated using the nonlinear Schrödinger equation. Numerical simulations indicate that the distribution factor b can influence the formation of the ring Airy Gaussian beams. Results show that the beams can be oscillating, and the light filament can be achieved under appropriate laser input power. On the other hand, the evolution of the ring Airy Gaussian beams with a spiral phase in the nonlinear Kerr medium can be implemented, and the numerical simulations of the holographic generation of the ring Airy Gaussian vortex beams propagated in the medium demonstrate that the vortex can be preserved along the propagation. The Poynting vector shows that the energy flow of the ring Airy Gaussian beams flows in the opposite direction on both sides of the focus plane; however, for beams with a spiral phase, the flow direction remains the same; the energy flow can rotate in opposite directions on both sides of the focal plane.
Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain
NASA Astrophysics Data System (ADS)
Zhang, Qi; Tan, Chaohua; Huang, Guoxiang
2016-02-01
We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system.
Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain.
Zhang, Qi; Tan, Chaohua; Huang, Guoxiang
2016-01-01
We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system. PMID:26891795
Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain
Zhang, Qi; Tan, Chaohua; Huang, Guoxiang
2016-01-01
We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system. PMID:26891795
Analysis of optical trapping and propulsion of Rayleigh particles using Airy beam.
Cheng, Hua; Zang, Weiping; Zhou, Wenyuan; Tian, Jianguo
2010-09-13
The radiation forces and trajectories of Rayleigh dielectric particles induced by one-dimensional Airy beam were numerically analyzed. Results show that the Airy beam drags particles into the optical intensity peaks, and guides particles vertically along parabolic trajectories. Viscosity of surrounding medium significantly affects the trajectories. Random Brownian force affects the trajectories. Meanwhile, trapping potential depths and minimum trapping particle radii in different potential wells were also discussed. The trapping stability could be improved by increasing either the input peak intensity or the particle radius. PMID:20940930
Arrays of Gaussian vortex, Bessel and Airy beams by computer-generated hologram
NASA Astrophysics Data System (ADS)
Lu, Yang; Jiang, Bo; Lü, Shuchao; Liu, Yongqi; Li, Shasha; Cao, Zheng; Qi, Xinyuan
2016-03-01
We generate various kinds of arrays of Gaussian vortex, Bessel and Airy beams, respectively, with digital phase holograms (DPH) based on the fractional-Talbot effect by using the phase-only spatial light modulator (SLM). The linear and nonlinear transmissions of these beam arrays in strontium barium niobate (SBN) crystal are investigated numerically and experimentally. Compared with Gaussian vortex arrays, Bessel and Airy beam arrays can keep their patterns unchanged in over 20 mm, realizing non-diffracting transmission. The Fourier spectra (far-field diffraction patterns) of the lattices are also studied. The experimental results are in good agreement with the numerical simulations.
Bose-Einstein condensation of {alpha} particles and Airy structure in nuclear rainbow scattering
Ohkubo, S.; Hirabayashi, Y.
2004-10-01
It is shown that the dilute density distribution of {alpha} particles in nuclei can be observed in the Airy structure in nuclear rainbow scattering. We have analyzed {alpha}+{sup 12}C rainbow scattering to the 0{sub 2}{sup +} (7.65 MeV) state of {sup 12}C in a coupled-channel method with the precise wave functions for {sup 12}C. It is found that the enhanced Airy oscillations in the experimental angular distributions for the 0{sub 2}{sup +} state is caused by the dilute density distribution of this state in agreement for the idea of Bose-Einstein condensation of the three alpha particles.
Anomalous change of Airy disk with changing size of spherical particles
NASA Astrophysics Data System (ADS)
Pan, Linchao; Zhang, Fugen; Meng, Rui; Xu, Jie; Zuo, Chenze; Ge, Baozhen
2016-02-01
Use of laser diffraction is considered as a method of reliable principle and mature technique in measurements of particle size distributions. It is generally accepted that for a certain relative refractive index, the size of the scattering pattern (also called Airy disk) of spherical particles monotonically decreases with increasing particle size. This fine structure forms the foundation of the laser diffraction method. Here we show that the Airy disk size of non-absorbing spherical particles becomes larger with increasing particle size in certain size ranges. To learn more about this anomalous change of Airy disk (ACAD), we present images of Airy disk and curves of Airy disk size versus particle size for spherical particles of different relative refractive indices by using Mie theory. These figures reveal that ACAD occurs periodically for non-absorbing particles and will disappear when the absorbing efficiency is higher than certain value. Then by using geometrical optics (GO) approximation, we derive the analytical formulae for the bounds of the size ranges where ACAD occurs. From the formulae, we obtain laws of ACAD as follows: (1) for non-absorbing particles, ACAD occurs periodically, and when the particle size tends to infinity, the period tends to a certain value. As the relative refractive index increases, (2) the particle size ranges where ACAD occurs shift to smaller values, (3) the period of ACAD becomes smaller, and (4) the width of the size ranges where ACAD occurs becomes narrower. In addition, we can predict from the formulae that ACAD also exists for particles whose relative refractive index is smaller than 1.
A compact Airy beam light sheet microscope with a tilted cylindrical lens.
Yang, Zhengyi; Prokopas, Martynas; Nylk, Jonathan; Coll-Lladó, Clara; Gunn-Moore, Frank J; Ferrier, David E K; Vettenburg, Tom; Dholakia, Kishan
2014-10-01
Light-sheet imaging is rapidly gaining importance for imaging intact biological specimens. Many of the latest innovations rely on the propagation-invariant Bessel or Airy beams to form an extended light sheet to provide high resolution across a large field of view. Shaping light to realize propagation-invariant beams often relies on complex programming of spatial light modulators or specialized, custom made, optical elements. Here we present a straightforward and low-cost modification to the traditional light-sheet setup, based on the open-access light-sheet microscope OpenSPIM, to achieve Airy light-sheet illumination. This brings wide field single-photon light-sheet imaging to a broader range of endusers. Fluorescent microspheres embedded in agarose and a zebrafish larva were imaged to demonstrate how such a microscope can have a minimal footprint and cost without compromising on imaging quality. PMID:25360362
Nonlinear dynamics of Airy-vortex 3D wave packets: emission of vortex light waves.
Driben, Rodislav; Meier, Torsten
2014-10-01
The dynamics of 3D Airy-vortex wave packets is studied under the action of strong self-focusing Kerr nonlinearity. Emissions of nonlinear 3D waves out of the main wave packets with the topological charges were demonstrated. Because of the conservation of the total angular momentum, charges of the emitted waves are equal to those carried by the parental light structure. The rapid collapse imposes a severe limitation on the propagation of multidimensional waves in Kerr media. However, the structure of the Airy beam carrier allows the coupling of light from the leading, most intense peak into neighboring peaks and consequently strongly postpones the collapse. The dependence of the critical input amplitude for the appearance of a fast collapse on the beam width is studied for wave packets with zero and nonzero topological charges. Wave packets carrying angular momentum are found to be much more resistant to the rapid collapse. PMID:25360922
Wavelength estimation by using the Airy disk from a diffraction pattern with didactic purposes
NASA Astrophysics Data System (ADS)
Rivera-Ortega, Uriel; Pico-Gonzalez, Beatriz
2016-01-01
In this paper a simple and easy to implement method that uses the Airy disk generated from a Fraunhofer diffraction pattern due to a circular aperture will be used to estimate the wavelength of the illuminating laser source. This estimation is based on the measurement of the Airy disk diameter, whose approximation is directly proportional to the wavelength of the light source and to the distance between the aperture and the image plane; and inversely proportional to the diameter of the aperture. Due to the characteristics and versatility of the present proposal, this is perfectly suitable for use in graduate or undergraduate physics laboratories, or even in classrooms for educational and/or demonstrative purposes.
A compact Airy beam light sheet microscope with a tilted cylindrical lens
Yang, Zhengyi; Prokopas, Martynas; Nylk, Jonathan; Coll-Lladó, Clara; Gunn-Moore, Frank J.; Ferrier, David E. K.; Vettenburg, Tom; Dholakia, Kishan
2014-01-01
Light-sheet imaging is rapidly gaining importance for imaging intact biological specimens. Many of the latest innovations rely on the propagation-invariant Bessel or Airy beams to form an extended light sheet to provide high resolution across a large field of view. Shaping light to realize propagation-invariant beams often relies on complex programming of spatial light modulators or specialized, custom made, optical elements. Here we present a straightforward and low-cost modification to the traditional light-sheet setup, based on the open-access light-sheet microscope OpenSPIM, to achieve Airy light-sheet illumination. This brings wide field single-photon light-sheet imaging to a broader range of endusers. Fluorescent microspheres embedded in agarose and a zebrafish larva were imaged to demonstrate how such a microscope can have a minimal footprint and cost without compromising on imaging quality. PMID:25360362
Dr. Airy's "morbid affection of the eyesight": lessons from Teichopsia Circa 1870.
Lepore, Frederick E
2014-09-01
Hubert Airy's iconic drawing of his own migraine visual aura for which he coined the term, "teichopsia," conveys important lessons for the contemporary clinician. His observations of the expansion ("build-up"), minification/magnification, and color/achromatopsia of migrainous teichopsia are consistent with (and possibly anticipatory of) the later discoveries of cortical spreading depression, cortical magnification of primary visual cortex (V1), and specialized cortical centers for color vision. PMID:24840023
Shaping symmetric Airy beam through binary amplitude modulation for ultralong needle focus
Fang, Zhao-Xiang; Gong, Lei; Ren, Yu-Xuan; Vaveliuk, Pablo; Chen, Yue; Lu, Rong-De
2015-11-28
Needle-like electromagnetic field has various advantages for the applications in high-resolution imaging, Raman spectroscopy, as well as long-distance optical transportation. The realization of such field often requires high numerical aperture (NA) objective lens and the transmission masks. We demonstrate an ultralong needle-like focus in the optical range produced with an ordinary lens. This is achieved by focusing a symmetric Airy beam (SAB) generated via binary spectral modulation with a digital micromirror device. Such amplitude modulation technique is able to shape traditional Airy beams, SABs, as well as the dynamic transition modes between the one-dimensional and two-dimensional (2D) symmetric Airy modes. The created 2D SAB was characterized through measurement of the propagating fields with one of the four main lobes blocked by an opaque mask. The 2D SAB was verified to exhibit self-healing property against propagation with the obstructed major lobe reconstructed after a certain distance. We further produced an elongated focal line by concentrating the SAB via lenses with different NAs and achieved an ultralong longitudinal needle focus. The produced long needle focus will be applied in optical, chemical, and biological sciences.
NASA Astrophysics Data System (ADS)
Yuan, Wu
2015-12-01
We discuss a novel method for generating hyper-broadband mid-infrared (MIR) supercontinua (SC) with coherent bandwidth from ~2 μm to ~10 μm by using As2Se3 photonic crystal fiber (PCF) and a 4.1 μm pump with femtosecond (fs) Airy pulse profile. Our simulations confirm that, when pumping in the normal dispersion region, the deceleration and self-healing properties of the Airy pulse can suppress the incoherent noise in modulational instability (MI) induced SC generation and maintain the pulse coherence over a long propagation distance. We also find that fs Airy pulse can generate an MIR SC with a broader coherent bandwidth than these can be achieved with fs parabolic secant pulse.
Complex Airy analysis of photoreflectance spectra for III-V semiconductors
NASA Astrophysics Data System (ADS)
Estrera, J. P.; Duncan, W. M.; Glosser, R.
1994-03-01
We present a detailed analysis of photoreflectance (PR) spectra of semiconductors using complex Airy functions and their derivatives. We demonstrate that photoreflectance spectra can be treated in terms of a single complex Airy function with an energy-dependent broadening parameter. We show analytically and numerically that this complex Airy PR treatment is functionally equivalent within field conditions appropriate for PR to the model of R. N. Bhattacharya, H. Shen, P. Parayanthal, F. H. Pollak, T. Coutts, and A. Aharoni [Phys. Rev. B 37, 4044 (1988)], where the effects of gradient electric field and non-flat-band modulation are treated explicitly. The equivalence occurs because the field gradient and non-flat-band modulation effects are included in our model in the energy dependence of the phenomenological broadening parameter Γ*=(Γ0/ħθ)exp[δ(ħω-Eg)], where ħω is the photon energy, Eg is the band-gap energy, Γ0 is the nominal broadening at the band-gap energy, and δ is a parameter directly proportional to the electric-field gradient and modulation between two finite fields. The major utility of our model is that a single effective layer can be treated instead of a more computationally intensive laminar model. We apply our complex Airy model to bulk semiconductors such as GaAs, InP, and InxGa1-xAs. In the photoreflectance spectra of these semiconductors, our model considers three distinct but convolved features at E0 which represent the light- and heavy-hole valence bands and an exciton-impurity feature below E0. At E0+Δ0 our model considers two features which are related to the spin-orbit-split valence band and a second state just below this critical point. For GaAs, we determined from our PR modeling that the band-gap energy for these films was 1.422+/-0.003 eV, which agreed, within experimental error, with the band-gap energy measured by room-temperature photoluminescence. A feature was found below the E0 gap in the GaAs samples with energies
Generation of χ(2) solitons from the Airy wave through the parametric instability.
Mayteevarunyoo, Thawatchai; Malomed, Boris A
2015-11-01
Spontaneous creation of solitons in quadratic media by the downconversion (i.e., parametric instability against the generation of fundamental-frequency excitations) from the truncated Airy-wave (AW) mode in the second-harmonic component is studied. Parameter regions are identified for the generation of one, two, and three solitons, with additional small-amplitude "jets." Shares of the total power carried by individual solitons are found. Also considered are soliton patterns generated by the downconversion from a pair of AWs bending in opposite directions. PMID:26512490
Two-dimensional χ^2 solitons generated by the downconversion of Airy waves
NASA Astrophysics Data System (ADS)
Mayteevarunyoo, Thawatchai; Malomed, Boris A.
2016-07-01
Conversion of truncated Airy waves (AWs) carried by the second-harmonic (SH) component into axisymmetric $\\chi^{2}$ solitons is considered in the 2D system with the quadratic nonlinearity. The spontaneous conversion is driven by the parametric instability of the SH wave. The input in the form of the AW vortex is considered too. As a result, one, two, or three stable solitons emerge in a well-defined form, unlike the recently studied 1D setting, where the picture is obscured by radiation jets. Shares of the total power captured by the emerging solitons and conversion efficiency are found as functions of parameters of the AW input.
Airy Equation for the Topological String Partition Function in a Scaling Limit
NASA Astrophysics Data System (ADS)
Alim, Murad; Yau, Shing-Tung; Zhou, Jie
2016-06-01
We use the polynomial formulation of the holomorphic anomaly equations governing perturbative topological string theory to derive the free energies in a scaling limit to all orders in perturbation theory for any Calabi-Yau threefold. The partition function in this limit satisfies an Airy differential equation in a rescaled topological string coupling. One of the two solutions of this equation gives the perturbative expansion and the other solution provides geometric hints of the non-perturbative structure of topological string theory. Both solutions can be expanded naturally around strong coupling.
Test drilling and aquifer test in the Marburg schist near Mount Airy, Frederick County, Maryland
Meyer, Gerald
1955-01-01
This memorandum summarizes briefly the data obtained by test drilling and in an aquifer test at Mount Airy, Md. The tests were a part of the State - Federal cooperative study of the ground-water resources of Frederick County, and it is intended that a more complete analysis of the test data will be included in a future report describing the ground-water resource of Frederick County. The purpose of this memorandum is to make the test data immediately available to the general public. Mount Airy is located along the Carroll-Frederick County boundary bout 2 miles north of the intersection of U.S. Highway 40 with the county boundary. Its population is approximately 1,000. The municipal well field, consisting of two drilled wells (fig. 1) is in a valley about one-half mile west of the center of Mount Airy, within about 400 feet of a small stream, and north of Prospect Road. Well 1, about 40 feet north of Prospect Road, is 125 feet deep, 8 inches in diameter, and reportedly yielded 265 gallons per minute (gpm) in 1947 and 201 gpm in a half hour test in March 1955. The writer determined during the tests described in this memorandum that the well has about 34 feet of casing. Well 2, 85 feet north of well 1, is 96 feet deep, 8 inches in diameter, and reportedly yielded 120 gpm in 1947 and 127 gpm in a half hour test in March 1955. The wells are equipped with deep-well turbine pumps powered by electric motors. Cenorally only well 1 is used, and it is pumped for only a few short intervals each day to meet the water requirements of the town (about 75,000 - 80,000 gallons daily). The reported yields of these wells are considerably higher than the average for crystalline-rock wells in the Piedmont of Maryland. The test drilling was done under contract with Edward I. Brown, well driller, between May 3 and May 12, 1955. Water-supply facilities of the town of Mount Airy were kindly made available for the aquifer tests from May 22 to May 30, 1955. The pumping tests consisted of a
Airy Equation for the Topological String Partition Function in a Scaling Limit
NASA Astrophysics Data System (ADS)
Alim, Murad; Yau, Shing-Tung; Zhou, Jie
2016-04-01
We use the polynomial formulation of the holomorphic anomaly equations governing perturbative topological string theory to derive the free energies in a scaling limit to all orders in perturbation theory for any Calabi-Yau threefold. The partition function in this limit satisfies an Airy differential equation in a rescaled topological string coupling. One of the two solutions of this equation gives the perturbative expansion and the other solution provides geometric hints of the non-perturbative structure of topological string theory. Both solutions can be expanded naturally around strong coupling.
Two-dimensional χ^{2} solitons generated by the downconversion of Airy waves.
Mayteevarunyoo, Thawatchai; Malomed, Boris A
2016-07-01
Conversion of truncated Airy waves (AWs) carried by the second-harmonic (SH) component into axisymmetric χ^{2} solitons is considered in a 2D system with quadratic nonlinearity. The spontaneous conversion is driven by the parametric instability of the SH wave. The input in the form of the AW vortex is also considered. As a result, one, two, or three stable solitons emerge in a well-defined form, unlike the recently studied 1D setting, where the picture is obscured by radiation jets. Shares of the total power captured by the emerging solitons and conversion efficiency are found as functions of parameters of the AW input. PMID:27367065
Bound states of breathing Airy-Gaussian beams in nonlocal nonlinear medium
NASA Astrophysics Data System (ADS)
Zhang, Xiaping
2016-05-01
With a nonlocal model, we investigate the propagation dynamics of a single Airy-Gaussian (AiG) beam and their interaction in one-dimensional condition by means of direct numerical simulations. With the split-step Fourier method, numerical results shows that nonlocality can support periodic intensity distribution of AiG beams leading to the formation of stable bound states. Especially, by tuning the phase difference between the two beams, we can steer the center of the bound AiG beams in nonlocal nonlinear media.
Martinez-Vara, P; Barranco, J Silva; De Los Santos G, S I; Munoz-Lopez, J; Torres-Rodriguez, M A; Xique, R Suarez; Martinez-Niconoff, G
2015-08-01
We analyze the diffraction field generated by coherent illumination of a three-dimensional transmittance characterized by a slit-shape curve. Generic features are obtained using the Frenet-Serret equations, which allow a decomposition of the optical field. The analysis is performed by describing the influence of the curvature and torsion on osculating, normal, and rectifying planes. We show that the diffracted field has a decomposition in three optical fields propagating along three optical axes that are mutually perpendicular. The decomposition is in terms of the Pearcey and Airy functions, and the generalized Airy function. Experimental results are shown. PMID:26258341
What is the diffraction limit? From Airy to Abbe using direct numerical integration
NASA Astrophysics Data System (ADS)
Calm, Y. M.; Merlo, J. M.; Burns, M. J.; Kempa, K.; Naughton, M. J.
The resolution of a conventional optical microscope is sometimes taken from Airy's point spread function (PSF), 0 . 61 λ / NA , and sometimes from Abbe, λ / 2 NA , where NA is the numerical aperture, however modern fluorescence and near-field optical microscopies achieve spatial resolution far better than either of these limits. There is a new category of 2D metamaterials called planar optical elements (POEs), which have a microscopic thickness (< λ), macroscopic transverse dimensions (> 100 λ), and are composed of an array of nanostructured light scatterers. POEs are found in a range of micro- and nano-photonic technologies, and will influence the future optical nanoscopy. With this pretext, we shed some light on the 'diffraction limit' by numerically evaluating Kirchhoff's scalar formulae (in their exact form) and identifying the features of highly non-paraxial, 3D PSFs. We show that the Airy and Abbe criteria are connected, and we comment on the design rules for a particular type of POE: the flat lens. This work is supported by the W. M. Keck Foundation.
NASA Astrophysics Data System (ADS)
Duxbury, Thomas; Neukum, Gerhard; Smith, David E.; Christensen, Philip; Neumann, Gregory; Albee, Arden; Caplinger, Michael; Seregina, N. V.; Kirk, Randolph L.
The small crater Airy-0 was selected from Mariner 9 images to be the reference for the Mars prime meridian. Initial analyses were made in year 2000 to tie Viking Orbiter and Mars Orbiter Camera images of Airy-0 to the evolving Mars Orbiter Laser Altimeter global digital terrain model to improve the location accuracy of Airy-0. Based upon this tie and radiometric tracking of landers / rovers from earth, new expressions for the Mars spin axis direction, spin rate and prime meridian epoch value were produced to define the orientation of the Martian surface in inertial space over time. Now that the Mars Global Surveyor mission and the Mars Orbiter Laser Altimeter global digital terrain model are complete, a more exhaustive study has been performed to determine the location of Airy-0 relative to the global terrain grid. THEMIS IR image cubes of the Airy and Gale crater regions were tied to the global terrain grid using precision stereo photogrammetric image processing techniques. The Airy-0 location was determined to be within 50 meters of the currently defined IAU prime meridian, with this offset at the limiting absolute accuracy of the global terrain grid. Additional outputs of this study were a controlled multi-band photomosaic of Airy, precision alignment and geometric models of the ten THEMIS IR bands and a controlled multi-band photomosaic of Gale crater used to validate the Mars Surface Laboratory operational map products supporting their successful landing on Mars.
Zhong, Xianqiong; Du, Xiantong; Cheng, Ke
2015-11-16
We numerically simulate the propagation of finite energy Airy pulses in optical fibers with cubic-quintic nonlinearity and analyze the effects of quintic nonlinear parameters and soliton order number on their evolution properties. The soliton pulses are observed, whose peak amplitudes and corresponding temporal positions will vary with the propagation distance. Depending on different quintic nonlinearity parameters and soliton order number, the soliton pulse temporal positions exhibit weak decayed oscillations and then nearly linearly shift to leading or trailing edge of the Airy wavepacket, or tend to fixed positions, and the peak amplitudes also exhibit decayed oscillations but with different oscillation amplitude and central values. For large soliton order number, the soliton pulses are considerably compressed. Other weak dispersive wave pulses will appear near the main soliton pulses and gradually depart from the main soliton pulses. In the case of small soliton order, despite their considerable energy attenuation, the main lobes and even minority of the neighboring side lobes of the Airy pulses can still recover from the energy transfer to the soliton pulses and the dispersive wave pulses and maintain their unique properties of self-healing and self-acceleration in time for a very long distance. In the case of large soliton order, however, the Airy wavepacket only remains its very weak background and even disappears quickly. PMID:26698430
Predicting the past: ancient eclipses and Airy, Newcomb, and Huxley on the authority of science.
Stanley, Matthew
2012-06-01
Greek historical accounts of ancient eclipses were an important, if peculiar, focus of scientific attention in the nineteenth century. Victorian-era astronomers tried to correct the classical histories using scientific methods, then used those histories as data with which to calibrate their lunar theories, then rejected the histories as having any relevance at all. The specific dating of these eclipses--apparently a simple exercise in celestial mechanics--became bound up with tensions between scientific and humanistic approaches to the past as well as with wider social debates over the power and authority of science in general. The major figures discussed here, including G. B. Airy, Simon Newcomb, and T. H. Huxley, argued that the critical question was whether science could speak authoritatively about the past. To them, the ability of science to talk about the past indicated its power to talk about the future; it was also the fulcrum of fierce boundary disputes among science, history, and religion. PMID:22908421
Propagation of an Airy-Gaussian vortex beam in linear and nonlinear media
NASA Astrophysics Data System (ADS)
Chen, Chidao; Peng, Xi; Chen, Bo; Peng, Yulian; Zhou, Meiling; Yang, Xiangbo; Deng, Dongmei
2016-05-01
We investigate the propagation of an Airy-Gaussian vortex (AiGV) beam in free space and Kerr media. It is interesting to see that the beam will perform self-healing and main lobe focusing both in free space and Kerr media when the vortex locates at the center of the plane. By controlling the number of the topological charge, the beam distribution factor χ 0 and the position of the vortex, we can control the intensity distribution of the AiGV beam in the out plane both in free space and Kerr media. It is found that when the vortex is close to the center of the plane, it has a strong effect on the intensity distribution of the beam. When the beam propagates in the number of the topological charge, the partial collapse will take place even with low initial input power. We find that the main lobe focusing contributes to this partial collapse.
NASA Astrophysics Data System (ADS)
Burton, Megan M.; Cruger, William E.; Gittins, Christopher; Kindle, Harry; Ricks, Timothy P.
2005-11-01
Captive flight testing (CFT) of sensors and seekers requires accurate data collection and display for sensor performance evaluation. The U.S. Army Redstone Technical Test Center (RTTC), in support of the U.S. Army Edgewood Chemical Biological Center (ECBC), has developed a data collection suite to facilitate airborne test of hyperspectral chemical/biological sensors. The data collection suite combines global positioning system (GPS) tracking, inertial measurement unit (IMU) data, accurate timing streams, and other test scenario information. This data collection suite also contains an advanced real-time display of aircraft and sensor field-of-view information. The latest evolution of this system has been used in support of the Adaptive InfraRed Imaging Spectroradiometer (AIRIS), currently under development by Physical Sciences Incorporated for ECBC. For this test, images from the AIRIS sensor were overlaid on a digitized background of the test area, with latencies of 1 second or less. Detects of surrogate chemicals were displayed and geo-referenced. Video overlay was accurate and reliable. This software suite offers great versatility in the display of imaging sensor data; support of future tests with the AIRIS sensor are planned as the system evolves.
Plume Aerosol Size Distribution Modeling and Comparisons to PrAIRie2005 Field Study Data
NASA Astrophysics Data System (ADS)
Cho, S.; Liggio, J.; Makar, P.; Li, S.; Racinthe, J.
2006-12-01
As part of the analysis phase of the PrAIRie2005 field study, the effects of different Edmonton-area emission sources on local air-quality are being examined. Four large coal-fired power-plants are located to the West of the city. Here, the effects of these power-plants on urban and regional air-quality will be examined, using both plume and regional air-quality models. During the last few decades, coal-fired power plants have been found to be as a major source of pollution, affecting public-health. According to NACEC (North American Commission for Environmental Corporation, 2001)'s report, 46 of the top 50 air polluters in North America were power plants. The importance of such sources has resulted in several attempts to improve understanding of the basic formation mechanisms of plume particulate matter. Sulphur dioxide contributes to acidifying emissions and to the production of secondary acidic aerosols that have been linked to a number of serious human health problems, acid rain and visibility (Seinfeld and Pandis, 1998; Hidy, 1984; Wilson and McMurray, 1981). Primary particulate matter originating directly from coal-fired power plants may also increase secondary particulate mass by providing a surface for sulphuric acid absorption . Environment Canada's PrAIRie2005 field study between August 12th and September 7th, 2005 included overflights and downwind measurements near the Edmonton powerplants (Wabamun, Sundance, Keephills and Genesee). The data collected consisted of particle size distributions, ozone, NOX, total mass and the chemical composition of fine particles. In order to investigate and improve our understanding of the formation mechanisms and physical properties of power-plant-generated aerosols in the Edmonton area, the Plume Aerosol Microphysical (PAM) model has been employed. This model accounts for gas-phase chemistry, aerosol microphysical processes (i.e. homogeneous/heterogeneous nucleation, condensation/evaporation and coagulation) and
NASA Astrophysics Data System (ADS)
Nayak, M.; Garrick-Bethell, I.; Hemingway, D.
2014-12-01
Lunar swirls are enigmatic high-albedo surface markings co-located with magnetic anomalies. The existence of mini-magnetospheres has been proposed as a formation mechanism, making small-scale magnetic field interactions with the solar wind of interest. Using data from the Lunar Prospector, Clementine, and Advanced Composition Explorer missions, we develop three metrics for the identification of mini-magnetospheres: 1) presence of coherent magnetism at low altitude for magnetic field measurements taken in the solar wind; 2) directional field distortions that are correlated with changes in incident solar wind azimuth; 3) intensification of total field strength. These metrics are applied to four lunar magnetic anomalies with various reflectances and magnetic field strengths, ranging from fully developed swirls (Reiner-Gamma, Airy) to diffuse albedo patches which may or may not be swirls (Descartes, Crozier). Specifically, we compare magnetic field measurements in the solar wind to source magnetization models constructed from observations in the lunar wake and Earth's magnetotail. By applying these criteria, we confirm previous findings of magnetosphere-like phenomena at Reiner-Gamma. We also find evidence of these phenomena at Descartes and Airy, and propose that mini-magnetospheres may exist here. At Airy, very large upwind distortions are observed, comparable to the length scale of the anomaly itself. At Reiner-Gamma and Descartes, this distortion is significantly smaller, yet the average field strengths are higher, implying that the scale of distortion is linked to the anomaly's field strength. Interestingly, at Crozier, the weakest anomaly considered, we do not observe this distortion. However, we do observe evidence of field intensification at high solar wind pressures (16 nPa). While Descartes and Reiner-Gamma are among the strongest anomalies on the Moon, and both exhibit magnetospheric properties, only Reiner-Gamma shows a well-developed swirl pattern
Acoustic Resonance of a Two-Dimensional Isotropic Medium Studied Using Airy Stress Function
NASA Astrophysics Data System (ADS)
Tarumi, Ryuichi; Yamada, Shinpei; Shibutani, Yoji
2012-07-01
We have developed a theory that determines a complete set of stress field, σij, in a freely vibrating two-dimensional isotropic medium within the framework of the calculus of variation. Our formulation is based on the Airy stress function φ and the minimization of the complementary strain energy under the constrain condition || φ|| 2L2 =const. By the Ritz method, the constrained variational problem becomes a linear eigenvalue problem. Numerical analysis yields 36 types of the stress functions φi. Unlike the stress fields determined from the conventional resonant ultrasound spectroscopy theory, the stress fields derived from the stress functions φi explicitly satisfy the stress-free natural boundary condition and the equilibrium equation. It is also confirmed that the 36 resonant modes can be classified into four groups according to the parity of the coefficient of the basis function. Furthermore, the stress functions φi are orthogonal in the sense of the L2 inner product. These features are similar to those of the conventional resonant ultrasound spectroscopy (RUS) theory.
Propagation properties of Airy-Gaussian vortex beams through the gradient-index medium.
Zhao, Ruihuang; Deng, Fu; Yu, Weihao; Huang, Jiayao; Deng, Dongmei
2016-06-01
Propagation of Airy-Gaussian vortex (AiGV) beams through the gradient-index medium is investigated analytically and numerically with the transfer matrix method. Deriving the analytic expression of the AiGV beams based on the Huygens diffraction integral formula, we obtain the propagate path, intensity and phase distributions, and the Poynting vector of the first- and second-order AiGV beams, which propagate through the paraxial ABCD system. The ballistic trajectory is no longer conventional parabolic but trigonometric shapes in the gradient-index medium. Especially, the AiGV beams represent the singular behavior at the propagation path and the light intensity distribution. The phase distribution and the Poynting vector exhibit in reverse when the AiGV beams through the singularity. As the order increases, the main lobe of the AiGV beams is gradually overlapped by the vortex core. Further, the sidelobe weakens when the AiGV beams propagate nearly to the singularity. Additionally, the figure of the Poynting vector of the AiGV beams proves the direction of energy flow corresponding to the intensity distribution. The vortex of the second-order AiGV beams is larger, and the propagation velocity is faster than that of the first order. PMID:27409428
Manipulation of Raman-induced frequency shift by use of asymmetric self-accelerating Airy pulse.
Zhang, Lifu; Zhong, Haizhe; Li, Ying; Fan, Dianyuan
2014-09-22
We investigate the evolution of asymmetric self-accelerating finite energy Airy pulses (FEAP) in optical fibers with emphasis on the role of Raman scattering. We show that the Raman-induced frequency shift (RIFS) of soliton initiated by an asymmetric self-accelerating FEAP depends not only on the launched peak power but also on the truncation coefficient imposed on the asymmetric self-accelerating FEAP. We find that the RIFS of asymmetric self-accelerating FEAP increases with a decrease in the truncation coefficient, while the peak power and spectrum width of the outermost red shift of the shedding soliton spectrum are almost unchanged. The time and frequency shifts of the shedding soliton are found to be sensitive to the truncation coefficient when the truncation coefficient is in the range of 0 to 0.1. These excellent features would lead to the realization of a RIFS-based tunable light source by launching self-accelerating FEAP with different truncation coefficient into an optical fiber. PMID:25321729
NASA Astrophysics Data System (ADS)
Liu, Weiwei; Lu, Yao; Gong, Lei; Chu, Xiuxiang; Xue, Guosheng; Ren, Yuxuan; Zhong, Mincheng; Wang, Ziqiang; Zhou, Jinhua; Li, Yinmei
2016-07-01
A symmetric Airy beam (SAB) autofocuses during free space propagation. Such autofocusing SAB is useful in optical manipulation and biomedical imaging. However, its inherently limited autofocusing property may degrade the performance of the SAB in those applications. To enhance the autofocus, a symmetric apodization mask was proposed to regulate the SAB. In combination with the even cubic phase that shapes the SAB, this even exponential function mask with an adjustable parameter regulates the contribution of different frequency spectral components to the SAB. The propagation properties of this new amplitude modulated SAB (AMSAB) were investigated both theoretically and experimentally. Simulation shows that the energy distribution and autofocusing property of an AMSAB can be adjusted by the exponential amplitude modulation. Especially, the beam energy will be more concentrated in the central lobe once the even cubic phase is modulated by the mask with a higher proportion of high-frequency spectral components. Consequently, the autofocusing property and axial gradient force of AMSABs are efficiently enhanced. The experimental generation and characterization for AMSABs were implemented by modulating the collimated beam with a phase-only spatial light modulator. The experimental results well supported the theoretical predictions. With the ability to enhance the autofocus, the proposed exponential apodization modulation will make SAB more powerful in various applications, including optical trapping, fluorescence imaging and particle acceleration.
NASA Astrophysics Data System (ADS)
Duxbury, T. C.; Christensen, P.; Smith, D. E.; Neumann, G. A.; Kirk, R. L.; Caplinger, M. A.; Albee, A. A.; Seregina, N. V.; Neukum, G.; Archinal, B. A.
2014-12-01
The small crater Airy-0 was selected from Mariner 9 images to be the reference for the Mars prime meridian. Initial analyses in the year 2000 tied Viking Orbiter and Mars Orbiter Camera images of Airy-0 to the evolving Mars Orbiter Laser Altimeter global digital terrain model to update the location of Airy-0. Based upon this tie and radiometric tracking of landers/rovers from Earth, new expressions for the Mars spin axis direction, spin rate, and prime meridian epoch value were produced to define the orientation of the Martian surface in inertial space over time. Since the Mars Global Surveyor mission and Mars Orbiter Laser Altimeter global digital terrain model were completed some time ago, a more exhaustive study has been performed to determine the accuracy of the Airy-0 location and orientation of Mars at the standard epoch. Thermal Emission Imaging System (THEMIS) IR image cubes of the Airy and Gale crater regions were tied to the global terrain grid using precision stereo photogrammetric image processing techniques. The Airy-0 location was determined to be about 0.001° east of its predicted location using the currently defined International Astronomical Union (IAU) prime meridian location. Information on this new location and how it was derived will be provided to the NASA Mars Exploration Program Geodesy and Cartography Working Group for their assessment. This NASA group will make a recommendation to the IAU Working Group on Cartographic Coordinates and Rotational Elements to update the expression for the Mars spin axis direction, spin rate, and prime meridian location.
NASA Astrophysics Data System (ADS)
Al Sdran, N.; Maiz, F.
2016-06-01
The numerical solutions of the time independent Schrödinger equation of different one-dimensional potentials forms are sometime achieved by the asymptotic iteration method. Its importance appears, for example, on its efficiency to describe vibrational system in quantum mechanics. In this paper, the Airy function approach and the Numerov method have been used and presented to study the oscillator anharmonic potential V(x) = Ax2α + Bx2, (A>0, B<0), with (α = 2) for quadratic, (α =3) for sextic and (α =4) for octic anharmonic oscillators. The Airy function approach is based on the replacement of the real potential V(x) by a piecewise-linear potential v(x), while, the Numerov method is based on the discretization of the wave function on the x-axis. The first energies levels have been calculated and the wave functions for the sextic system have been evaluated. These specific values are unlimited by the magnitude of A, B and α. It's found that the obtained results are in good agreement with the previous results obtained by the asymptotic iteration method for α =3.
NASA Astrophysics Data System (ADS)
Zhang, Lifu; Liu, Kun; Zhong, Haizhe; Zhang, Jinggui; Deng, Jianqin; Li, Ying; Fan, Dianyuan
2015-07-01
Soliton propagation direction can be engineered in optical fibers in the presence of high-order effects (HOEs). It is well known that Raman effects can decelerate the soliton. Here we investigate the manipulation of the deceleration or acceleration of soliton emitted from Airy pulse whose spectrum is imposed an initial quadratic phase modulation (QPM) in optical fibers in the absence of HOEs. We show that, under the action of the anomalous second-order dispersion (SOD) and Kerr nonlinearity, Airy pulse with QPM is able to emit soliton with acceleration or deceleration depending on whether the QPM is negative or positive, and at a rate that is determined by the magnitude of QPM. The reason is that the acceleration behaviors of incident Airy pulse is altered depending on whether SOD and QPM have the same or opposite signs. Our study shows the possibility of controlling and manipulating the soliton propagation and interaction in optical fibers without HOEs, by purposely choosing appropriate QPM parameter of an Airy pulse.
Zhang, Lifu; Liu, Kun; Zhong, Haizhe; Zhang, Jinggui; Deng, Jianqin; Li, Ying; Fan, Dianyuan
2015-01-01
Soliton propagation direction can be engineered in optical fibers in the presence of high-order effects (HOEs). It is well known that Raman effects can decelerate the soliton. Here we investigate the manipulation of the deceleration or acceleration of soliton emitted from Airy pulse whose spectrum is imposed an initial quadratic phase modulation (QPM) in optical fibers in the absence of HOEs. We show that, under the action of the anomalous second-order dispersion (SOD) and Kerr nonlinearity, Airy pulse with QPM is able to emit soliton with acceleration or deceleration depending on whether the QPM is negative or positive, and at a rate that is determined by the magnitude of QPM. The reason is that the acceleration behaviors of incident Airy pulse is altered depending on whether SOD and QPM have the same or opposite signs. Our study shows the possibility of controlling and manipulating the soliton propagation and interaction in optical fibers without HOEs, by purposely choosing appropriate QPM parameter of an Airy pulse. PMID:26173387
Ruehl, W.
1996-05-01
One and two vector sigma models are defined that possess catastrophes in their action. Each catastrophe defines a double scaling limit at {ital N}{r_arrow}{infinity}. Critical indices are calculated and the Airy functions are shown to satisfy RG equations. Copyright {copyright} 1996 Academic Press, Inc.
Strehl-constrained reconstruction of post-adaptive optics data and the Software Package AIRY, v. 6.1
NASA Astrophysics Data System (ADS)
Carbillet, Marcel; La Camera, Andrea; Deguignet, Jérémy; Prato, Marco; Bertero, Mario; Aristidi, Éric; Boccacci, Patrizia
2014-08-01
We first briefly present the last version of the Software Package AIRY, version 6.1, a CAOS-based tool which includes various deconvolution methods, accelerations, regularizations, super-resolution, boundary effects reduction, point-spread function extraction/extrapolation, stopping rules, and constraints in the case of iterative blind deconvolution (IBD). Then, we focus on a new formulation of our Strehl-constrained IBD, here quantitatively compared to the original formulation for simulated near-infrared data of an 8-m class telescope equipped with adaptive optics (AO), showing their equivalence. Next, we extend the application of the original method to the visible domain with simulated data of an AO-equipped 1.5-m telescope, testing also the robustness of the method with respect to the Strehl ratio estimation.
NASA Astrophysics Data System (ADS)
Mirab, Hadi; Fathi, Reza; Jahangiri, Vahid; Ettefagh, Mir Mohammad; Hassannejad, Reza
2015-12-01
One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electrical energy. The advantage of this method is based on avoiding a battery charging system. Studies have been done on energy harvesting from sea waves, however, considering energy harvesting with random JONSWAP wave theory, then determining the optimum values of energy harvested is new. This paper does that by implementing the JONSWAP wave model, calculating produced power, and realistically showing that output power is decreased in comparison with the more simple airy wave model. In addition, parameters of the energy harvester system are optimized using a simulated annealing algorithm, yielding increased produced power.
Suhendi, Endi; Syariati, Rifki; Noor, Fatimah A.; Khairurrijal; Kurniasih, Neny
2014-03-24
We modeled a tunneling current in a p-n junction based on armchair graphene nanoribbons (AGNRs) by using an Airy function approach (AFA) and a transfer matrix method (TMM). We used β-type AGNRs, in which its band gap energy and electron effective mass depends on its width as given by the extended Huckel theory. It was shown that the tunneling currents evaluated by employing the AFA are the same as those obtained under the TMM. Moreover, the calculated tunneling current was proportional to the voltage bias and inversely with temperature.
NASA Astrophysics Data System (ADS)
McLeod, Douglas M.; McLeod, Roger D.
2002-10-01
DMM found that a distant, single church steeple, which appeared "twin-like" after extended studying episodes, could then be brought into correct visual register by a conscious effort. Similar anecdotal events are repeatable by attentive students or workers in the early stages of educationally or work environmentally induced repetitive vision impairment. RDM proposes that his model for vision and its repair utilizes sequentially applied vision improvement stages that are the equivalent of DMM's experience. Such visual events involve feedback signals generated during the crystalline lens's minor dioptric oscillations that are generated by the blinking reflex, empowered by the Airy radius proportional to wavelength times focal length divided by pupil aperture. This implies some conscious control of feedback mechanisms, which can self-regulate vision protecting processes. Continued visual effort under duress invokes Hooke's "stress proportional to strain." Exceeding extrinsic eye muscles' elastic limits overrides spontaneous feedback repair mechanisms.
Huang, Jiayao; Liang, Zijie; Deng, Fu; Yu, Weihao; Zhao, Ruihuang; Chen, Bo; Yang, Xiangbo; Deng, Dongmei
2015-11-01
The propagation of right-hand circularly polarized Airy-Gaussian beams (RHCPAiGBs) through slabs of right-handed materials (RHMs) and left-handed materials (LHMs) is investigated analytically and numerically with the transfer matrix method. An approximate analytical expression for the RHCPAiGBs passing through a paraxial ABCD optical system is derived on the basis of the Huygens diffraction integral formula. The intensity and the phase distributions of the RHCPAiGBs through RHMs and LHMs are demonstrated. The influence of the parameter χ_{0} on the propagation of RHCPAiGBs through RHM and LHM slabs is investigated. The RHCPAiGBs possess transverse-momentum currents, which shows that the physics underlying this intriguing accelerating effect is that of the combined contributions of the transverse spin and transverse orbital currents. Additionally, we go a step further to explore the radiation force including the gradient force and scattering force of the RHCPAiGBs. PMID:26560925
NASA Astrophysics Data System (ADS)
Cheng, Ke; Jiao, Liyang; Zhong, Xianqiong
2016-05-01
Based on the vector angular spectrum representation and stationary phase method, the analytical far-field vectorial expressions of radial noncanonical vortex Airy beam arrays (NVAiBAs) and radial noncanonical vortex Gaussian beam arrays (NVGBAs) are derived, and used to investigate their far-field vectorial properties, e.g. center optical vortices and energy fluxes of these corresponding beams, where the effect of noncanonical strength, topological charge, initial phase index and the number of beamlet on far-field vectorial properties of these corresponding beams is emphasized, respectively. The results show that the topological charge of center optical vortices in the far field is equal to initial phase index for the case of the radial NVAiBAs, whereas for radial NVGBAs the topological charge not only lies on initial phase index, but also is closely related to the odevity and sign of optical vortices embedded in beamlet, where mathematical analysis is made to explain the topological charge of center optical vortices, and the limitation of the number of beamlet to the topological charge of center optical vortices is also discussed. In addition, energy fluxes of radial NVAiBAs and NVGBAs exhibit different space orientations by controlling noncancial strength and present larger dark zones by increasing topological charge of beamlet, respectively. Finally, the relationship between the center optical vortices and energy fluxes of radial NVAiBAs and NVGBAs in even or odd N beamlets is also revealed, respectively.
NASA Astrophysics Data System (ADS)
Cho, S.; Makar, P. A.; Lee, W. S.; Herage, T.; Liggio, J.; Li, S. M.; Wiens, B.; Graham, L.
The effects of the accuracy of major-point source emissions input data on the predictions of a regional air-quality model (AURAMS) were investigated through a series of scenario simulations. The model domain and time period were chosen to correspond to that of PrAIRie2005, an air-quality field study with airborne and ground-based mobile measurement platforms that took place between August 12th and September 7th, 2005, over the city of Edmonton, Alberta, Canada. The emissions data from standard sources for three coal-fired power-plants located west (typically upwind) of the city were compared to the continuous emissions monitoring system (CEMS) taking place at the time of the study - the latter showed that the original emissions inventory data considerably overestimated NO x, SO 2, and primary particulate emissions during the study period. Further field investigation (stack sampling) in the fall of 2006 showed that the measured primary particle size distribution and chemical speciation for the emissions were strikingly different from the distribution and speciation originally used in the model. The measured emissions were used to scale existing emissions data in accord with the CEMS and in-stack measurements. The effects of these improvements to the emissions data were examined sequentially in nested AURAMS simulations (finest horizontal resolution 3 km), and were compared to airborne aerosol mass spectrometer (Aerodyne AMS) measurements of particle sulphate, and particle distributions from an airborne passive cavity aerosol spectrometer probe (PCASP). The emissions of SO 2 had the greatest impact on predicted PM 1 sulphate, while the primary particle size distribution and chemical speciation had a smaller role. The revised emissions data greatly improved the comparisons between observations and model values, though over-predictions of fine-mode sulphate still occur near the power-plants, with the use of the revised emissions data. The modified emissions also had a
Atmospherics: A Look at the Earth's Airy Shell.
ERIC Educational Resources Information Center
Byalko, A. V.
1991-01-01
Describes differences in the composition, pressure, and temperature at distinct altitudes of the Earth's atmosphere from the point of view of physical laws. Discusses the genesis and importance of ozone, thermal radiation and the "layer cake" arrangement of the atmosphere, and solar energy in connection with thermal equilibrium. (JJK)
Asymptotics for the Covariance of the Airy2 Process
NASA Astrophysics Data System (ADS)
Shinault, Gregory; Tracy, Craig A.
2011-04-01
In this paper we compute some of the higher order terms in the asymptotic behavior of the two point function {P}({A}2(0)≤ s1,A2(t)≤ s2), extending the previous work of Adler and van Moerbeke (arXiv:math.PR/0302329; Ann. Probab. 33, 1326-1361, 2005) and Widom (J. Stat. Phys. 115, 1129-1134, 2004). We prove that it is possible to represent any order asymptotic approximation as a polynomial and integrals of the Painlevé II function q and its derivative q'. Further, for up to tenth order we give this asymptotic approximation as a linear combination of the Tracy-Widom GUE density function f 2 and its derivatives. As a corollary to this, the asymptotic covariance is expressed up to tenth order in terms of the moments of the Tracy-Widom GUE distribution.
No Time for the "Airy Fairy": Teacher Perspectives on Creative Writing in High Stakes Environments
ERIC Educational Resources Information Center
Frawley, Emily
2014-01-01
This paper discusses a research project undertaken to examine teachers' perceptions of creative writing in the senior English curriculum. It was a case study undertaken in a state high school in Melbourne under the Victorian Certificate of Education (VCE). The project investigated the challenges facing English teachers as they prepare…
Two new cembranoids from the leaves of Croton longissimus Airy Shaw.
Kawakami, Susumu; Matsunami, Katsuyoshi; Otsuka, Hideaki; Lhieochaiphant, Duangporn; Lhieochaiphant, Sorasak
2013-04-01
Two new cembrane-type diterpenoids (1 and 2) along with five known compounds (3-7) were isolated from leaves of Croton longissimus collected in Thailand. Their structures were elucidated from spectroscopic evidence and compound 4 was found by HPLC analysis to be identical to oblongionoside B-a compound isolated from Croton oblongifolius-including the absolute configuration at the C-9 position. PMID:22926346
Starch-based aerogels: airy materials from amylose-sodium palmitate inclusion complexes
Technology Transfer Automated Retrieval System (TEKTRAN)
Aerogels are a class of interesting low density porous materials prepared by replacing the water phase contained within a hydrogel with a gas phase while maintaining the three dimensional network structure of the gel. The investigation of starch and hydrocolloid-based aerogels has received attentio...
Psychometric Properties of the Affect Intensity and Reactivity Measure Adapted for Youth (AIR-Y)
ERIC Educational Resources Information Center
Jones, Rachel E.; Leen-Feldner, Ellen W.; Olatunji, Bunmi O.; Reardon, Laura E.; Hawks, Erin
2009-01-01
A valid and reliable instrument for measuring affect intensity does not exist for adolescents; such a measure may help to refine understanding of emotion among youths. The purpose of the current study was to evaluate the psychometric properties and clinical relevance of a measure of affect intensity adapted for youths. Two hundred five community…
Brooks, Ross
2015-01-01
The hegemony of the two-sex paradigm in the European scientific imagination and wider culture did not automatically equate to the hegemony of two discrete genders. In fact, two sexes facilitated a variety of gender choices: two singular and a number of double or otherwise intersexed (most commonly referred to as "hermaphrodite" or "bisexual" in its anatomical sense). This article explores some key British medical and allied scientific texts, with reference to associated Continental literature, as a means of illustrating the complexity of the two-sex paradigm and the unexpected transformation of gender possibilities that it helped produce through the early and middle decades of the nineteenth century. Discourses surrounding the first direct observations of the earliest development of fetal urinogenital anatomy were pivotal. The prevailing view that the incipient embryo was sexually undifferentiated (a paragon of the one-sex paradigm) was challenged by the Edinburgh anatomist Robert Knox, initially as he sought to bolster his professional reputation at the height of the Burke and Hare "body-snatching" scandal. Knox suggested that every embryo began life in an essentially dual-sexed state, an individual's sex anatomy depending on the greater or lesser development of component female and male structures. Greater clarification on the contested status of the homology-hermaphrodite distinction was achieved with the discovery of the early co-existence of the excretory duct of the Wolffian body (mesonephric duct) and the Müllerian duct (paramesonephric duct), an observation that made anatomical bisexuality difficult to ignore. The nineteenth-century's greatest champion of primordial hermaphroditism was Charles Darwin who was pivotal in phylogenizing the principle and establishing the premise that (in his own words) "Every man & woman is hermaphrodite," a foundation stone of late-nineteenth-century sexology. PMID:24150887
Holographic generation of non-diffractive beams
NASA Astrophysics Data System (ADS)
Lee, Byoungho; Choi, Dawoon; Hong, Keehoon; Lee, Kyookeun; Kim, Kyoung-Youm
2014-11-01
An Airy beam is a non-diffractive wave which propagates along a ballistic trajectory without any external force. Although it is impossible to implement ideal Airy beams because they carry infinite power, so-called finite Airy beams can be achieved by tailoring infinite side lobes with an aperture function and they have similar propagating characteristics with those of ideal Airy beams. The finite Airy beam can be optically generated by several ways: the optical Fourier transform system with imposing cubic phase to a broad Gaussian beam, nonlinear generation of Airy beams, curved plasma channel generation, and electron beam generation. In this presentation, a holographic generation of the finite Airy beams will be discussed. The finite Airy beams can be generated in virtue of holographic technique by `reading' a hologram which is recorded by the interference between a finite Airy beam generated by the optical Fourier transform and a reference plane wave. Moreover, this method can exploit the unique features of holography itself such as successful reconstruction with the imperfect incidence of reference beam, reconstruction of phase-conjugated signal beam, and multiplexing, which can shed more light on the characteristics of finite Airy beams. This method has an advantage in that once holograms are recorded in the photopolymer, a bulky optics such as the SLM and lenses are not necessary to generate Airy beams. In addition, multiple Airy beams can be stored and reconstructed simultaneously or individually.
The two populations’ cellular automata model with predation based on the Penna model
NASA Astrophysics Data System (ADS)
He, Mingfeng; Lin, Jing; Jiang, Heng; Liu, Xin
2002-09-01
In Penna's single-species asexual bit-string model of biological ageing, the Verhulst factor has too strong a restraining effect on the development of the population. Danuta Makowiec gave an improved model based on the lattice, where the restraining factor of the four neighbours take the place of the Verhulst factor. Here, we discuss the two populations’ Penna model with predation on the planar lattice of two dimensions. A cellular automata model containing movable wolves and sheep has been built. The results show that both the quantity of the wolves and the sheep fluctuate in accordance with the law that one quantity increases while the other one decreases.
2. Historic American Buildings Survey Richard Koch, Photographer, April, 1934 ...
2. Historic American Buildings Survey Richard Koch, Photographer, April, 1934 SOUTHWEST ELEVATION - Angelina Plantation (Dove Cote & Doll House), State Highway 1, Mount Airy, St. John the Baptist Parish, LA
3. Historic American Buildings Survey Richard Koch, Photographer, April, 1934 ...
3. Historic American Buildings Survey Richard Koch, Photographer, April, 1934 SOUTHWEST ELEVATION - Angelina Plantation (Dove Cote & Doll House), State Highway 1, Mount Airy, St. John the Baptist Parish, LA
4. Historic American Buildings Survey Richard Koch, Photographer, Circa 1925 ...
4. Historic American Buildings Survey Richard Koch, Photographer, Circa 1925 FIREPLACE IN DOLL HOUSE - Angelina Plantation (Dove Cote & Doll House), State Highway 1, Mount Airy, St. John the Baptist Parish, LA
1. Historic American Buildings Survey Richard Koch, Photographer, Circa 1925 ...
1. Historic American Buildings Survey Richard Koch, Photographer, Circa 1925 DOVE COTE AND DOLL HOUSE - Angelina Plantation (Dove Cote & Doll House), State Highway 1, Mount Airy, St. John the Baptist Parish, LA
5. Historic American Buildings Survey Richard Koch, Photographer, March, 1934 ...
5. Historic American Buildings Survey Richard Koch, Photographer, March, 1934 VIEW FROM NORTH WEST - Angelina Plantation (Dove Cote & Doll House), State Highway 1, Mount Airy, St. John the Baptist Parish, LA
Spiders in the Crosshairs: Cobwebs, Instrument Makers, and the Search for the Perfect Line
NASA Astrophysics Data System (ADS)
Turner, Steven
The the methodology of acquiring, and the use of spider webs, and other resources for creating telescope crosshairs, by early observers, such as William Herschel, David Rittenhouse, Andrew Ellicott, George Airy, as we as a variety of early manufacturers.
Discrete beam acceleration in uniform waveguide arrays
El-Ganainy, Ramy; Makris, Konstantinos G.; Miri, Mohammad Ali; Christodoulides, Demetrios N.; Chen Zhigang
2011-08-15
Within the framework of the tight-binding model we demonstrate that Wannier-Stark states can freely accelerate in uniform optical lattices. As opposed to accelerating Airy wave packets in free space, our analysis reveals that in this case the beam main intensity features self-bend along two opposite hyperbolic trajectories. Two-dimensional geometries are also considered and an asymptotic connection between these Wannier-Stark ladders and Airy profiles is presented.
Computer program for Bessel and Hankel functions
NASA Technical Reports Server (NTRS)
Kreider, Kevin L.; Saule, Arthur V.; Rice, Edward J.; Clark, Bruce J.
1991-01-01
A set of FORTRAN subroutines for calculating Bessel and Hankel functions is presented. The routines calculate Bessel and Hankel functions of the first and second kinds, as well as their derivatives, for wide ranges of integer order and real or complex argument in single or double precision. Depending on the order and argument, one of three evaluation methods is used: the power series definition, an Airy function expansion, or an asymptotic expansion. Routines to calculate Airy functions and their derivatives are also included.
Unveiling orbital angular momentum and acceleration of light beams and electron beams
NASA Astrophysics Data System (ADS)
Arie, Ady
Special beams, such as the vortex beams that carry orbital angular momentum (OAM) and the Airy beam that preserves its shape while propagating along parabolic trajectory, have drawn significant attention recently both in light optics and in electron optics experiments. In order to utilize these beams, simple methods are needed that enable to easily quantify their defining properties, namely the OAM for the vortex beams and the nodal trajectory acceleration coefficient for the Airy beam. Here we demonstrate a straightforward method to determine these quantities by astigmatic Fourier transform of the beam. For electron beams in a transmission electron microscope, this transformation is easily realized using the condenser and objective stigmators, whereas for light beam this can be achieved using a cylindrical lens. In the case of Laguerre-Gauss vortex beams, it is already well known that applying the astigmatic Fourier transformation converts them to Hermite-Gauss beams. The topological charge (and hence the OAM) can be determined by simply counting the number of dark stripes of the Hermite-Gauss beam. We generated a series of electron vortex beams and managed to determine the topological charge up to a value of 10. The same concept of astigmatic transformation was then used to unveil the acceleration of an electron Airy beam. The shape of astigmatic-transformed depends only on the astigmatic measure and on the acceleration coefficient. This method was experimentally verified by generating electron Airy beams with different known acceleration parameters, enabling direct comparison to the deduced values from the astigmatic transformation measurements. The method can be extended to other types of waves. Specifically, we have recently used it to determine the acceleration of an optical Airy beams and the topological charge of so-called Airy-vortex light beam, i.e. an Airy light beam with an embedded vortex. This work was supported by DIP and the Israel Science
NASA Astrophysics Data System (ADS)
Chapman, Allan
2003-06-01
A careful study of the detailed archives of the Victorian Royal Observatory makes it possible to build up a picture of the employment and working conditions not only of the astronomical staff who worked at Greenwich, but also of the labourers, watchmen, and gate porters. Indeed, the archives open up a window on to how the Observatory was run on a daily basis: how its non-scientific staff were recruited and paid, and what were their terms of employment. They also say a great deal about how Sir George Biddell Airy directed and controlled every aspect of the Observatory's life. Yet while Airy was a strict employer, he emerges as a man who was undoubtedly fair-minded and sometimes even generous to his non-scientific work-force. A study of the Observatory staff files also reveals the relationship between the Observatory labouring staff and the Airy family's domestic servants. And of especial interest is the robbery committed by William Sayers, the Airy family footman in 1868, bringing to light as it does Sir George and Lady Richarda Airy's views on crime and its social causes and consequences, the prison rehabilitation service in 1868, and their opinions on the reform of offenders. Though this paper is not about astronomy as such, it illuminates a fascinating interface where the world of astronomical science met and worked alongside the world of ordinary Victorian people within the walls of one of the nineteenth century's most illustrious astronomical institutions.
Measurement of secondary ionization coefficient of CaO film electrode
NASA Astrophysics Data System (ADS)
Suzuki, Susumu; Kashiwagi, Yasuhide; Itoh, Haruo
2013-02-01
The secondary ionization coefficient γ of a CaO film electrode is investigated taking into account the difference in breakdown voltage obtained by repeated voltage applications. Such measurement is performed under a sinusoidal voltage of 0.5 Hz. If the CaO film electrode acts as the cathode, breakdown voltage gradually decreases and converges to an almost constant value after several breakdowns. From the obtained results, the γ of the CaO film electrode is determined for each breakdown using Townsend's criterion. The γ in the first breakdown is lower than those in subsequent breakdowns, particularly in the steady state. The difference in γ is considered to originate from accumulated charges on the CaO film electrode. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
LTE plasma reactors for materials conversion
NASA Astrophysics Data System (ADS)
Kolacinski, Zbigniew; Szymanski, Lukasz; Raniszewski, Grzegorz
2013-02-01
Plasma aided materials conversion is the use of charged particles for producing new materials with unusual and superior properties or to convert unwanted materials such as waste into environmentally friendly products. The near LTE plasma (in atmospheric or reduced pressure) is a nice tool for engineering of materials which in consequence upgrades the performance of most of the consumer goods. The paper presents a few samples of the own research results related to the design and use of some plasma reactors for synthesis of nanomaterials and hazardous materials destruction with their conversion into valuable products. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
NASA Astrophysics Data System (ADS)
Raniszewski, Grzegorz
2013-02-01
The article presents the plasma synthesis method of carbon nanotubes using an electric arc discharge. In this method different carbon nanotubes are produced as a cathode deposit growth or are deposed on various substrates such as silicon, metals and other materials. The examples of applications of carbon nanotubes in medical applications were presented. Conditions required for the synthesis of carbon nanotubes and process parameters were mentioned. Applications of carbon nanotubes for cancer treatment were discussed. The method of temperature measurement of the arc was described. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Li, Yixiang; Qiu, Chunyin; Xu, Shengjun; Ke, Manzhu; Liu, Zhengyou
2015-01-01
Conventional microparticle transports by light or sound are realized along a straight line. Recently, this limit has been overcome in optics as the growing up of the self-accelerating Airy beams, which are featured by many peculiar properties, e.g., bending propagation, diffraction-free and self-healing. However, the bending angles of Airy beams are rather small since they are only paraxial solutions of the two-dimensional (2D) Helmholtz equation. Here we propose a novel micromanipulation by using acoustic Half-Bessel beams, which are strict solutions of the 2D Helmholtz equation. Compared with that achieved by Airy beams, the bending angle of the particle trajectory attained here is much steeper (exceeding 90o). The large-angle bending transport of microparticles, which is robust to complex scattering environment, enables a wide range of applications from the colloidal to biological sciences. PMID:26279478
NASA Astrophysics Data System (ADS)
Li, Yixiang; Qiu, Chunyin; Xu, Shengjun; Ke, Manzhu; Liu, Zhengyou
2015-08-01
Conventional microparticle transports by light or sound are realized along a straight line. Recently, this limit has been overcome in optics as the growing up of the self-accelerating Airy beams, which are featured by many peculiar properties, e.g., bending propagation, diffraction-free and self-healing. However, the bending angles of Airy beams are rather small since they are only paraxial solutions of the two-dimensional (2D) Helmholtz equation. Here we propose a novel micromanipulation by using acoustic Half-Bessel beams, which are strict solutions of the 2D Helmholtz equation. Compared with that achieved by Airy beams, the bending angle of the particle trajectory attained here is much steeper (exceeding 90o). The large-angle bending transport of microparticles, which is robust to complex scattering environment, enables a wide range of applications from the colloidal to biological sciences.
Abruptly autofocusing terahertz waves with meta-hologram.
He, Jingwen; Wang, Sen; Xie, Zhenwei; Ye, Jiasheng; Wang, Xinke; Kan, Qiang; Zhang, Yan
2016-06-15
An abruptly autofocusing ring-Airy beam is demonstrated in the terahertz (THz) waveband with a meta-hologram. The designed meta-hologram is composed of gold C-shaped slot antennas, which can realize both phase and amplitude modulation of the incident THz wave. A THz holographic imaging system is utilized to measure the generated ring-Airy beam; an abrupt focus following a parabolic trajectory is subsequently observed. THz ring-Airy beams with different parameters are also generated and investigated. This method can be expanded to other wavebands, such as the visible band, for which the meta-hologram can replace traditional computer-generated holography to avoid undesirable multiple diffraction orders. PMID:27304289
New insights into the rainbow Part 1/2: Study on the physics of the supernumerary bows
NASA Astrophysics Data System (ADS)
Ricard, J. L.
2011-12-01
We have tested the basic assumptions of the Airy's theory. Surprisingly, they are only valid in a small angle close to the minimum deviation angle (less than 2 degrees). For instance in the supernumerary area, the Airy's theory has obvious flaws. In the Airy's model, two aspects of the diffraction are taken into account. Firstly, a phenomenon of interferences discovered by Young created by rays of light with different pathes through the droplets. Secondly, "simple diffraction" such as the one appearing on the both (shadowed and lighted) side of a straight edge. In this study, we show that the "simple diffraction" alone is enough for understanding the formation of the supernumerary arcs. Interferences contribute in fact only very little.
Li, Yixiang; Qiu, Chunyin; Xu, Shengjun; Ke, Manzhu; Liu, Zhengyou
2015-01-01
Conventional microparticle transports by light or sound are realized along a straight line. Recently, this limit has been overcome in optics as the growing up of the self-accelerating Airy beams, which are featured by many peculiar properties, e.g., bending propagation, diffraction-free and self-healing. However, the bending angles of Airy beams are rather small since they are only paraxial solutions of the two-dimensional (2D) Helmholtz equation. Here we propose a novel micromanipulation by using acoustic Half-Bessel beams, which are strict solutions of the 2D Helmholtz equation. Compared with that achieved by Airy beams, the bending angle of the particle trajectory attained here is much steeper (exceeding 90(o)). The large-angle bending transport of microparticles, which is robust to complex scattering environment, enables a wide range of applications from the colloidal to biological sciences. PMID:26279478
Richard Christopher Carrington: Briefly Among the Great Scientists of His Time
NASA Astrophysics Data System (ADS)
Cliver, Edward W.; Keer, Norman C.
2012-09-01
We recount the life and career of Richard Christopher Carrington (1826 - 1875) and explore his pivotal relationship with Astronomer Royal George Biddell Airy. Carrington was the pre-eminent solar astronomer of the 19th century. During a ten year span, he determined the position of the Sun's rotation axis and made the following discoveries: i) the latitude variation of sunspots over the solar cycle, ii) the Sun's differential rotation, and iii) the first solar flare (with Hodgson). Due to the combined effects of family responsibilities, failure to secure a funded position in astronomy (reflecting Airy's influence), and ill health, Carrington's productive period ended when he was at the peak of his powers.
Fisher, Sir Ronald Aylmer (1890-1962)
NASA Astrophysics Data System (ADS)
Murdin, P.
2000-11-01
Statistician, born in London, England. After studying astronomy using AIRY's manual on the Theory of Errors he became interested in statistics, and laid the foundation of randomization in experimental design, the analysis of variance and the use of data in estimating the properties of the parent population from which it was drawn. Invented the maximum likelihood method for estimating from random ...
Tracy-Widom at High Temperature
NASA Astrophysics Data System (ADS)
Allez, Romain; Dumaz, Laure
2014-09-01
We investigate the marginal distribution of the bottom eigenvalues of the stochastic Airy operator when the inverse temperature tends to . We prove that the minimal eigenvalue, whose fluctuations are governed by the Tracy-Widom law, converges weakly, when properly centered and scaled, to the Gumbel distribution. More generally we obtain the convergence in law of the marginal distribution of any eigenvalue with given index . Those convergences are obtained after a careful analysis of the explosion times process of the Riccati diffusion associated to the stochastic Airy operator. We show that the empirical measure of the explosion times converges weakly to a Poisson point process using estimates proved in Dumaz and Virág (Ann Inst H Poincaré Probab Statist 49(4):915-933, 2013). We further compute the empirical eigenvalue density of the stochastic Airy ensemble on the macroscopic scale when . As an application, we investigate the maximal eigenvalues statistics of -ensembles when the repulsion parameter when . We study the double scaling limit and argue with heuristic and numerical arguments that the statistics of the marginal distributions can be deduced following the ideas of Edelman and Sutton (J Stat Phys 127(6):1121-1165, 2007) and Ramírez et al. (J Am Math Soc 24:919-944, 2011) from our later study of the stochastic Airy operator.
ERIC Educational Resources Information Center
Biemiller, Lawrence
2007-01-01
Charles Carroll Jr. would be long forgotten but for a single notable accomplishment: he built an exceedingly handsome house. Begun in 1801 with money from his wealthy father-- Charles Carroll of Carrollton, the only Roman Catholic signer of the Declaration of Independence-- the Federal-style home has near-perfect proportions and airy rooms. The…
Leidos Reclaims Defelice Cup at Annual Golf Tournament | Poster
By Ashley DeVine, Staff Writer Leidos Biomedical Research reclaimed the Defelice Cup trophy from NCI at the eighth annual Ronald H. Defelice golf tournament, held October 14. The final score was 15–7, with Leidos Biomed tying the series 4 to 4. Fourteen players on each team battled it out at Rattlewood golf course in Mount Airy, Md.
FTIR-based airborne spectral imagery for target interrogation
NASA Astrophysics Data System (ADS)
Smithson, Tracy L.; St. Germain, Daniel; Nadeau, Denis
2007-09-01
DRDC Valcartier is continuing to developed infrared spectral imagery systems for a variety of military applications. Recently a hybrid airborne spectral imager / broadband imager system has been developed for ground target interrogation (AIRIS). This system employs a Fourier Transform Interferometer system coupled to two 8x8 element detector arrays to create spectral imagery in the region from 2.0 to 12 microns (830 to 5000 cm -1) at a spectral resolution of up to 1 cm -1. In addition, coupled to this sensor are three broadband imagers operating in the visible, mid-wave and long-wave infrared regions. AIRIS uses an on-board tracking capability to: dwell on a target, select multiple targets sequentially, or build a mosaic description of the environment around a specified target point. Currently AIRIS is being modified to include real-time spectral imagery calibration and application processing. In this paper the flexibility of the AIRIS system will be described, its concept of operation discussed and examples of measurements will be shown.
Nonlocalization of Nonlocal Symmetry and Symmetry Reductions of the Burgers Equation
NASA Astrophysics Data System (ADS)
Jin, Yan; Jia, Man; Lou, Sen-Yue
2012-12-01
Symmetry reduction method is one of the best ways to find exact solutions. In this paper, we study the possibility of symmetry reductions of the well known Burgers equation including the nonlocal symmetry. The related new group invariant solutions are obtained. Especially, the interactions among solitons, Airy waves, and Kummer waves are explicitly given.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-06
... (77 FR 36292). Patricia A. Brink, Director of Civil Enforcement, Antitrust Division. BILLING CODE 4410... Robotics, Sherman Oaks, CA; Global Technical Systems, Virginia Beach, VA; Hurley IR, Mount Airy, MD; ICx Tactical Platforms, Forest Park, GA; Innovative Signal Analysis, Inc., Richardson, TX; Liquid...
The Martian Prime Meridian -- Longitude 'Zero'
NASA Technical Reports Server (NTRS)
2001-01-01
[figure removed for brevity, see original site]
On Earth, the longitude of the Royal Observatory in Greenwich, England is defined as the 'prime meridian,' or the zero point of longitude. Locations on Earth are measured in degrees east or west from this position. The prime meridian was defined by international agreement in 1884 as the position of the large 'transit circle,' a telescope in the Observatory's Meridian Building. The transit circle was built by Sir George Biddell Airy, the 7th Astronomer Royal, in 1850. (While visual observations with transits were the basis of navigation until the space age, it is interesting to note that the current definition of the prime meridian is in reference to orbiting satellites and Very Long Baseline Interferometry (VLBI) measurements of distant radio sources such as quasars. This 'International Reference Meridian' is now about 100 meters east of the Airy Transit at Greenwich.)
For Mars, the prime meridian was first defined by the German astronomers W. Beer and J. H. Madler in 1830-32. They used a small circular feature, which they designated 'a,' as a reference point to determine the rotation period of the planet. The Italian astronomer G. V. Schiaparelli, in his 1877 map of Mars, used this feature as the zero point of longitude. It was subsequently named Sinus Meridiani ('Middle Bay') by Camille Flammarion.
When Mariner 9 mapped the planet at about 1 kilometer (0.62 mile) resolution in 1972, an extensive 'control net' of locations was computed by Merton Davies of the RAND Corporation. Davies designated a 0.5-kilometer-wide crater (0.3 miles wide), subsequently named 'Airy-0' (within the large crater Airy in Sinus Meridiani) as the longitude zero point. (Airy, of course, was named to commemorate the builder of the Greenwich transit.) This crater was imaged once by Mariner 9 (the 3rd picture taken on its 533rd orbit, 533B03) and once by the Viking 1 orbiter in 1978 (the 46th image on that spacecraft's 746th orbit
NASA Astrophysics Data System (ADS)
Goyal, Amit; Raju, Thokala Soloman; Kumar, C. N.; Panigrahi, Prasanta K.
2016-04-01
We analytically explore optical rogue waves in a nonlinear graded-index waveguide, with spatially modulated dispersion, nonlinearity, and linear refractive-index. We study the evolution of first-order rogue wave and rogue wave triplet on Airy-Bessel, sech2, and tanh background beams, and reveal that the characteristics of RWs are well maintained while the amplitude of the first-order RW gets enhanced three times the maximum value of the Airy-Bessel and sech2 background beams and five times in the case of RW triplet. These results could be of great interest in realizing the RWs in experimentally realizable situations on small-amplitude background beams in nonlinear optics.
NASA Astrophysics Data System (ADS)
Yang, An; Huang, Jinshui; Wei, Daiyun
2016-09-01
Assuming that the long-wavelength geoid and topography of Venus are supported by both mantle convection and Airy isostasy, we propose a method to separate the dynamic and isostatic components of the Venusian gravity and topography with the aid of the dynamic admittance from numerical models of mantle convection and the isostatic admittance from an Airy isostatic model. The global crustal thickness is then calculated based on the isostatic component of the gravity and topography. The results show that some highland plateaus such as Ishtar Terra and Ovda Regio have thick crust, which are largely supported by isostatic compensation. Other highland plateaus such as Thetis and Phoebe Regiones appear to have superimposed contributions from crustal thickening and dynamic support. Volcanic rises such as Atla and Beta Regiones have thin crust, which is consistent with the postulation that these volcanic rises are mainly the products of dynamic uplift caused by mantle plumes.
Geoid height versus topography for oceanic plateaus and swells
NASA Technical Reports Server (NTRS)
Sandwell, David T.; Mackenzie, Kevin R.
1989-01-01
Gridded geoid height data (Marsh et al.l, 1986) and gridded bathymetry data (Van Wykhouse, 1973) are used to estimate the average compensation depths of 53 oceanic swells and plateaus. The relationship between geoid height and topography is examined using Airy and thermal compensation models. It is shown that geoid height is linearly related to topography between wavelengths of 400 and 4000 m as predicted by isostatic compensation models. The geoid/topography ratio is dependent on the average depth of compensation. The intermediate geoid/topography ratios of most thermal swells are interpreted as a linear combination of the decaying thermal swell signature and that of the persisting Airy-compensated volcanic edifice.
Accurate Thermal Stresses for Beams: Normal Stress
NASA Technical Reports Server (NTRS)
Johnson, Theodore F.; Pilkey, Walter D.
2003-01-01
Formulations for a general theory of thermoelasticity to generate accurate thermal stresses for structural members of aeronautical vehicles were developed in 1954 by Boley. The formulation also provides three normal stresses and a shear stress along the entire length of the beam. The Poisson effect of the lateral and transverse normal stresses on a thermally loaded beam is taken into account in this theory by employing an Airy stress function. The Airy stress function enables the reduction of the three-dimensional thermal stress problem to a two-dimensional one. Numerical results from the general theory of thermoelasticity are compared to those obtained from strength of materials. It is concluded that the theory of thermoelasticity for prismatic beams proposed in this paper can be used instead of strength of materials when precise stress results are desired.
Accurate Thermal Stresses for Beams: Normal Stress
NASA Technical Reports Server (NTRS)
Johnson, Theodore F.; Pilkey, Walter D.
2002-01-01
Formulations for a general theory of thermoelasticity to generate accurate thermal stresses for structural members of aeronautical vehicles were developed in 1954 by Boley. The formulation also provides three normal stresses and a shear stress along the entire length of the beam. The Poisson effect of the lateral and transverse normal stresses on a thermally loaded beam is taken into account in this theory by employing an Airy stress function. The Airy stress function enables the reduction of the three-dimensional thermal stress problem to a two-dimensional one. Numerical results from the general theory of thermoelasticity are compared to those obtained from strength of materials. It is concluded that the theory of thermoelasticity for prismatic beams proposed in this paper can be used instead of strength of materials when precise stress results are desired.
The dynamics of diffracted rays in foams
NASA Astrophysics Data System (ADS)
Tufaile, A.; Tufaile, A. P. B.
2015-12-01
We have studied some aspects of the optics of the light scattering in foams. This paper describes the difference between rays and diffracted rays from the point of view of geometrical theory of diffraction. We have represented some bifurcations of light rays using dynamical systems. Based on our observations of foams, we created a solid optical device. The interference patterns of light scattering in foams forming Airy fringes were explored observing the pattern named as the eye of Horus. In the cases we examine, these Airy fringes are associated with light scattering in curved surfaces, while the halo formation is related to the law of edge diffraction. We are proposing a Pohl interferometer using a three-sided bubble/Plateau border system.
Marston, P L
1998-03-20
Glare points associated with the Airy caustics of once and twice internally reflected rays are visible in the scattering by sunlit icicles. Supporting color photographs include an image of the far-field scattering. Relevant rays are analogous to the Descartes rays of primary and secondary rainbows of drops; however, the caustic conditions for the icicle are predicted to be affected by tilt of the illumination relative to the axis of the icicle. A model for the caustic evolution, given for a circular dielectric cylinder, manifests a transition in which the Airy caustic (and associated glare points) merge in the meridional plane at a critical tilt. At this critical tilt the merged glare point is predicted to be very bright. The calculations use the Bravais effective refractive index and generalized ray tracing. PMID:18268747
Können, G P; de Boer, J H
1979-06-15
The Airy theory of the rainbow is extended to polarized light. For both polarization directions a simple analytic expression is obtained for the intensity distribution as a function of the scattering angle in terms of the Airy function and its derivative. This approach is valid at least down to droplet diameters of 0.3 mm in visible light. The degree of polarization of the rainbow is less than expected from geometrical optics; it increases with droplet size. For a droplet diameter >1 mm the locations of the supernumerary rainbows are equal for both polarization directions, but for a diameter <1 mm the supernumerary rainbows of the weaker polarization component are located between those in the strong component. PMID:20212586
Scattering of an electromagnetic plane wave by a Luneburg lens. I. Ray theory.
Lock, James A
2008-12-01
For a plane wave incident on either a Luneburg lens or a modified Luneburg lens, the magnitude and phase of the transmitted electric field are calculated as a function of the scattering angle in the context of ray theory. It is found that the ray trajectory and the scattered intensity are not uniformly convergent in the vicinity of edge ray incidence on a Luneburg lens, which corresponds to the semiclassical phenomenon of orbiting. In addition, it is found that rays transmitted through a large-focal-length modified Luneburg lens participate in a far-zone rainbow, the details of which are exactly analytically soluble in ray theory. Using these results, the Airy theory of the modified Luneburg lens is derived and compared with the Airy theory of the rainbows of a homogeneous sphere. PMID:19037388
NASA Astrophysics Data System (ADS)
Luther, P.
In this bibliography a concise biographical chronology of the following astronomers is given: George Biddell Airy (1801 - 1892), Robert Stawell Ball (1840 - 1913), George Phillips Bond (1825 - 1865), William Cranch Bond (1789 - 1859), Agnes Mary Clerke (1842 - 1907), John Frederick William Herschel (1792 - 1871), Edward Singleton Holden (1846 - 1914), Joseph Norman Lockyer (1836 - 1920), Percival Lowell (1855 - 1916), Ormsby MacKnight Mitchel (1809 - 1862), Simon Newcomb (1835 - 1909), Richard Anthony Proctor (1837 - 1888), Mary Fairfax Greig Somerville (1780 - 1872).
Solving the {sup 12}C+{sup 12}C scattering puzzle: is there the '4th elephant'?
Demyanova, A. S.; Danilov, A. N.; Ogloblin, A. A.; Goncharov, S. A.; Bohlen, H. G.; Khlebnikov, S. V.; Tyurin, G. P.; Maslov, V. A.; Penionzkevich, Yu. E.; Sobolev, Yu. G.; Trzaska, W.
2010-04-30
Differential cross sections of the {sup 12}C+{sup 12}C and the {sup 13}C+{sup 12}C elastic scattering were measured at the projectile energies 240 MeV ({sup 12}C) and 250 MeV ({sup 13}C) up to the largest angles. The positions of the 1{sup st} Airy minima known from the former experiments were confirmed.
Application of boundary integral method to elastic analysis of V-notched beams
NASA Technical Reports Server (NTRS)
Rzasnicki, W.; Mendelson, A.; Albers, L. U.
1973-01-01
A semidirect boundary integral method, using Airy's stress function and its derivatives in Green's boundary integral formula, is used to obtain an accurate numerical solution for elastic stress and strain fields in V-notched beams in pure bending. The proper choice of nodal spacing on the boundary is shown to be necessary to achieve an accurate stress field in the vicinity of the tip of the notch. Excellent agreement is obtained with the results of the collocation method of solution.
Precise evaluation of the Helmholtz equation for optical propagation.
Pond, John E; Sutton, George W
2015-01-01
A precise computational integration of the Helmholtz equation was performed for laser propagation of an electromagnetic wave with no approximations or linearization. This computation integration was performed using 64-bit processors. This is illustrated for a uniform monochromatic beam from a circular aperture that has a uniform intensity. It predicts many Arago spots and near-field intensity fluctuations for a large ratio of aperture size to wavelength and converges to the usual Airy pattern in the far field. PMID:25531618
Padé approximation of Laplace transforms of some special functions in terms of Painlevé equations
NASA Astrophysics Data System (ADS)
Nakamura, Yoshimasa; Ohira, Norihiro
2004-10-01
Only in a limiting case has a closed form of the Laplace transforms of special functions been known (Abramowitz M and Stegun I A 1970 Handbook of Mathematical Functions (New York: Dover)). It is shown that Padé approximations of Laplace transforms of the Airy, Hermite-Weber, Bessel functions are computed by using Bäcklund transformations of the Painlevé equations in a purely algebraic manner.
Methodology of contact stress analysis of gearwheel by means of experimental photoelasticity.
Frankovský, Peter; Ostertag, Oskar; Trebuňa, František; Ostertagová, Eva; Kelemen, Michal
2016-06-20
The subject of this paper is the analysis of contact stresses that occur between the teeth of a gear. The analysis was carried out by means of reflection photoelasticity, which is an experimental method rarely used in this field. Contact stresses assessed in the experiment are compared with values assessed through an analytical calculation while using the Airy stress function or Hertzian relations. PMID:27409110
New insights into classical solutions of the local instability of the sandwich panels problem
NASA Astrophysics Data System (ADS)
Pozorska, Jolanta; Pozorski, Zbigniew
2016-06-01
The paper concerns the problem of local instability of thin facings of a sandwich panel. The classic analytical solutions are compared and examined. The Airy stress function is applied in the case of the state of plane stress and the state of plane strain. Wrinkling stress values are presented. The differences between the results obtained using the differential equations method and energy method are discussed. The relations between core strain energies are presented.
NASA Astrophysics Data System (ADS)
Krisch, J. P.; Glass, E. N.
2014-10-01
A set of cylindrical solutions to Einstein's field equations for power law densities is described. The solutions have a Bessel function contribution to the metric. For matter cylinders regular on axis, the first two solutions are the constant density Gott-Hiscock string and a cylinder with a metric Airy function. All members of this family have the Vilenkin limit to their mass per length. Some examples of Bessel shells and Bessel motion are given.
Alpha particle condensation in {sup 12}C and nuclear rainbow scattering
Ohkubo, S.; Hirabayashi, Y.
2008-05-12
It is shown that the large radius of the Hoyle state of {sup 12}C with a dilute density distribution in an {alpha} particle condensate can be clearly seen in the shift of the rainbow angle (therefore the Airy minimum) to a larger angle in {alpha}+{sup 12}C rainbow scattering at the high energy region and prerainbow oscillations in {sup 3}He+{sup 12}C scattering at the lower energy region.
What Brown saw and you can too
NASA Astrophysics Data System (ADS)
Pearle, Philip; Collett, Brian; Bart, Kenneth; Bilderback, David; Newman, Dara; Samuels, Scott
2010-12-01
A discussion of Robert Brown's original observations of particles ejected by pollen of the plant Clarkia pulchella undergoing what is now called Brownian motion is given. We consider the nature of those particles and how he misinterpreted the Airy disk of the smallest particles to be universal organic building blocks. Relevant qualitative and quantitative investigations with a modern microscope and with a "homemade" single lens microscope similar to Brown's are presented.
NASA Astrophysics Data System (ADS)
Koval'ová, Zuzana; Tarabová, Kataŕna; Hensel, Karol; Machala, Zdenko
2013-02-01
Cold air plasmas of DC and pulsed corona discharges: positive streamers and negative Trichel pulses were used for bio-decontamination of Streptococci biofilm and Bacillus cereus spores on polypropylene plastic surfaces. The reduction of bacterial population (evaluated as log10) in the biofilm on plastic surfaces treated by DC corona reached 2.4 logs with 10 min treatment time and 3.3 logs with 2 min treatment time with water spraying. The enhancement of plasma biocidal effects on the biofilm by electro-spraying of water through a hollow needle high-voltage electrode was investigated. No significant polarity effect was found with DC corona. Pulsed corona was demonstrated slightly more bactericidal for spores, especially in the negative polarity where the bacterial population reduction reached up to 2.2 logs at 10 min exposure time. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Free fatty acids degradation in grease trap purification using ozone bubbling and sonication
NASA Astrophysics Data System (ADS)
Piotr Kwiatkowski, Michal; Satoh, Saburoh; Fukuda, Shogo; Yamabe, Chobei; Ihara, Satoshi; Nieda, Masanori
2013-02-01
The oil and fat were treated at first by only ozone bubbling and it was confirmed that the collection efficiency of them became 98.4% when the aeration was used. It showed that the aeration method in a grease trap cleared the standard value of 90% and there was no worry on the oil and fat outflow from a grease trap. The characteristics of sonication process were studied for free fatty acids degradation. The free saturated fatty acids are the most hard-degradable compounds of the fats, oils and greases (FOGs) in the grease trap. The influence of various parameters such as immersion level of an ultrasound probe in the liquid and bubbling of various gases (Ar, O2, air, O3) on the sonochemical and energy efficiency of the sonication process was investigated. The most effective degradation treatment method for saturated free fatty acids was the combination of sonication and low flow rate argon bubbling. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Plasma deposition of antimicrobial coating on organic polymer
NASA Astrophysics Data System (ADS)
Rżanek-Boroch, Zenobia; Dziadczyk, Paulina; Czajkowska, Danuta; Krawczyk, Krzysztof; Fabianowski, Wojciech
2013-02-01
Organic materials used for packing food products prevent the access of microorganisms or gases, like oxygen or water vapor. To prolong the stability of products, preservatives such as sulfur dioxide, sulfites, benzoates, nitrites and many other chemical compounds are used. To eliminate or limit the amount of preservatives added to food, so-called active packaging is sought for, which would limit the development of microorganisms. Such packaging can be achieved, among others, by plasma modification of a material to deposit on its surface substances inhibiting the growth of bacteria. In this work plasma modification was carried out in barrier discharge under atmospheric pressure. Sulfur dioxide or/and sodium oxide were used as the coating precursors. As a result of bacteriological studies it was found that sulfur containing coatings show a 16% inhibition of Salmonella bacteria growth and 8% inhibition of Staphylococcus aureus bacteria growth. Sodium containing coatings show worse (by 10%) inhibiting properties. Moreover, films with plasma deposited coatings show good sealing properties against water vapor. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Fourth Bionanotox and Applications Research Conference, 2009
NASA Astrophysics Data System (ADS)
Camp, Judy
2010-04-01
"Anticipating the future" seemed the common challenge for scientists attending the 4th BioNanoTox and Applications Research Conference in Little Rock, AR, October 21-22, 2009. Over 50 participants in multi-disciplines such as biology, chemistry, physics, medicine, medical diagnostics, computer science and informatics, nanotechnology, toxicology, and pharmaceutical science gathered to share their research data. From topics on water and food resources to space exploration to conservation to understanding biological activities and using instruments and computers that process enormous data, participants shared research approaches from different fields to find common themes in this integrated field. Presentations aimed at preventing the harmful effects of scientific discoveries to animals, humans, plants, and environment; at controlling infections; and at optimizing health care. The conference included addresses from Thomas Flammang, PhD, of the Food and Drug Administration, National Center for Toxicological Research in Jefferson, AR; Little Rock City Mayor Mark Stodola; and two keynote speakers. Keynote lectures by Danuta Leszczynska, PhD, from the Department of Civil and Environmental Engineering, Interdisciplinary Nanotoxicity Center, in Jackson, MS, and by Keith Cowan, PhD, from the Institute for Environmental Biotechnology in Grahamstown, South Africa, highlighted current trends and future challenges of nanoparticle research and of bioprocess technologies. Additionally, 25 graduate and undergraduate students presented research posters, resulting in valuable discussion among the varied participants; three student projects were selected for awards.
Oxidation of nitrogen oxide in hybrid plasma-catalytic reactors based on DBD and Fe2O3
NASA Astrophysics Data System (ADS)
Jõgi, Indrek; Erme, Kalev; Haljaste, Ants; Laan, Matti
2013-02-01
In the present study, Fe2O3 was used as catalyst for the removal of NO in a hybrid plasma- catalytic reactor. The catalyst was located either directly inside the hybrid plasma-catalytic reactor or in a separate catalytic reactor, which followed ozone producing and injecting plasma reactor. Ozone production in such a reactor was dependent on the state of the electrode surface. The fresh catalyst ensured an order of magnitude smaller ozone concentration in the outlet of the hybrid reactor. After a short treatment of the catalyst with NO2, its ability to destroy ozone diminished but was regained after heating of the reactor up to 100 °C. Similarly to earlier results obtained with TiO2, the removal of NO in the hybrid reactor with Fe2O3 was enhanced compared to that in an ordinary plasma reactor. In the ozone injection reactor, oxidation of NO to NO2 took place with considerably higher efficiency compared to the hybrid reactor. The use of catalyst in the ozonation stage further improved the oxidation of NO2 to N2O5. The time-dependence effects of NO removal during plasma and ozone oxidation were explained by reactions between NO2 adsorbed on surface, with surface-bound NO3 and gas phase NO as the reaction product. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
NASA Astrophysics Data System (ADS)
Nakamiya, Toshiyuki; Mitsugi, Fumiaki; Iwasaki, Yoichiro; Ikegami, Tomoaki; Tsuda, Ryoichi; Sonoda, Yoshito; Danuta Stryczewska, Henryka
2013-02-01
The phase modulation of transparent gas can be detected using Fraunhofer diffraction technique, which we call optical wave microphone (OWM). The OWM is suitable for the detection of sonic wave from audible sound to ultrasonic wave. Because this technique has no influence on sound field or electric field during the measurement, we have applied it to the sound detection for the electric discharges. There is almost no research paper that uses the discharge sound to examine the electrical discharge phenomenon. Two-dimensional visualization of the sound field using the OWM is also possible when the computerized tomography (CT) is combined. In this work, coplanar dielectric barrier discharge sin different gases of Ar, N2, He were characterized via the OWM as well as applied voltage and discharge current. This is the first report to investigate the influence of the type of the atmospheric gas on the two-dimensional sound field distribution for the coplanar dielectric barrier discharge using the OWM with CT. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Oxidative methane conversion in dielectric barrier discharge
NASA Astrophysics Data System (ADS)
Krawczyk, Krzysztof; Młotek, Michał; Ulejczyk, Bogdan; Pryciak, Krzysztof; Schmidt-Szałowski, Krzysztof
2013-02-01
A dielectric barrier discharge was used for the oxidative coupling of methane (OCM) with oxygen at the pressure of 1.2 bar. A dielectric barrier discharge (DBD) reactor was powered at the frequency of about 6 kHz. Molar ratio CH4/O2 in the inlet gas containing 50% or 25% of argon was 3, 6 and 12. The effects of temperature (110, 150 and 340 ◦C), gas flow rate, molar ratio of methane to oxygen on the overall methane and oxygen conversion and methane conversion to methanol, ethanol, hydrocarbons, carbon oxides and water were studied. In the studied system the increase of the temperature decreases the conversion of methane to methanol. The increase of the molar ratio of methane to oxygen increased the methane conversion to hydrocarbons and strongly decreased the methane conversion to alcohols. The conversion of methane to hydrocarbons increased and the conversion of methane to methanol decreased with the decrease of the gas flow rate from 2 to 1 NL/h. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Ozone-mist spray sterilization for pest control in agricultural management
NASA Astrophysics Data System (ADS)
Ebihara, Kenji; Mitsugi, Fumiaki; Ikegami, Tomoaki; Nakamura, Norihito; Hashimoto, Yukio; Yamashita, Yoshitaka; Baba, Seiji; Stryczewska, Henryka D.; Pawlat, Joanna; Teii, Shinriki; Sung, Ta-Lun
2013-02-01
We developed a portable ozone-mist sterilization system to exterminate pests (harmful insects) in agricultural field and greenhouse. The system is composed of an ozone generator, an ozone-mist spray and a small container of ozone gas. The ozone generator can supply highly concentrated ozone using the surface dielectric barrier discharge. Ozone-mist is produced using a developed nozzle system. We studied the effects of ozone-mist spray sterilization on insects and agricultural plants. The sterilization conditions are estimated by monitoring the behavior of aphids and observing the damage of the plants. It was shown that aphids were exterminated in 30 s without noticeable damages of the plant leaves. The reactive radicals with strong oxidation potential such as hydroxyl radical (*OH), hydroperoxide radical (*HO2), the superoxide ion radical (*O2‒) and ozonide radical ion (*O3‒) can increase the sterilization rate for aphids. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Formations of negative ions in Sf6/N2 mixtures and their transport at atmospheric pressure
NASA Astrophysics Data System (ADS)
Okuyama, Yui; Sabo, Martin; Itoh, Haruo; Matejčík, Štefan
2013-02-01
Formation of negative ions initiated by interaction of thermal electrons and in the corona discharge (CD) in N2 with small admixture of SF6; was studied using the ion mobility spectrometry- orthogonal acceleration time-of-flight mass spectrometry (IMS-oaTOF) at atmospheric pressure. The negative ions have been analyzed by the ion mobility spectrometry and mass spectrometry (IMS-MS) and two-dimensional spectra (2D IMS-MS) have been recorded. We discuss the mechanisms of the negative ion formation in the N2/SF6 mixtures (0.003-0.018%) as well as the transport parameters of the ions in these mixtures. The values of the reduced ion mobilities of negative ions formed in these mixtures were determined (2.43 cm2/V s for HF2- (HF)n, 2.32 cm2/V s for NO3- (HF)n, 2.08 cm2/V s for SF5-, 2.01 cm2/V s for SOF5-, 2.00 for SOF4- 1.99 cm2/V s for SF6-, 1.83 cm2/V s for SOF5-(H2O)n and 1.73 for SOF5-(H2O)n(HF)m). The assignment of the ion mobility peaks was performed on the basis of the 2D IMS-MS spectra. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
Filamentation of Beam-Shaped Femtosecond Laser Pulses
Polynkin, Pavel; Kolesik, Miroslav; Moloney, Jerome
2010-10-08
When ultra-intense and ultra-short optical pulses propagate in transparent dielectrics, the dynamic balance between multiple linear and nonlinear effects results in the generation of laser filaments. These peculiar objects have numerous interesting properties and can be potentially used in a variety of applications from remote sensing to the optical pulse compression down to few optical cycles to guiding lightning discharges away from sensitive sites. Materializing this practical potential is not straightforward owing to the complexity of the physical picture of filamentation. In this paper, we discuss recent experiments on using beam shaping as a means of control over the filament formation and dynamics. Two particular beam shapes that we have investigated so far are Bessel and Airy beams. The diffraction-free propagation of femtosecond Bessel beams allows for the creation of extended plasma channels in air. These extended filaments can be used for the generation of energetic optical pulses with the duration in the few-cycle range. In the case of filamentation of femtosecond Airy beams, the self-bending property of these beams allows for the creation of curved filaments. This is a new regime of the intense laser-pulse propagation in which the linear self-bending property of the beam competes against the nonlinear self-channeling. The bent filaments generated by ultra-intense Airy beams emit forward-propagating broadband radiation. Analysis of the spatial and spectral distribution of this emission provides for a valuable tool for analyzing the evolution of the ultra-intense optical pulse along the optical path.
Art form as an object of cognitive modeling (towards development of Vygotsky`s semiotic model)
Dmitriev, V.; Perlovsky, L.I.
1996-12-31
We suggest a further development of Vygotsky`s esthetic-semiotic model. First, we discuss Vygotsky`s model originally developed for the analysis of Ivan Bunin`s story {open_quotes}Light Breath{close_quotes}. Vygotsky analyzes formal methods used by Bunin to achieve a specific esthetic effect of {open_quote}lightness{close_quotes} while describing {open_quotes}dirty{close_quotes} events of everyday life. According to Vygotsky, this effect is achieved by ordering of events in a non-linear fashion. Vygotsky creams an airy pattern of smooth lines connecting events of story that he first orders linearly in time. And, he insists that this airy pattern creates an impression of airy lightness. In the language of semiotics, the esthetic effect is created by a specific structural organization of signs. Second, we present our critique of Vygotsky`s model. Although, we do not agree with Vygotsky`s sometimes moralistic judgements, and we consider the dynamics between inner personal values and received moral values to be more complicated than implied in his judgements, our critique in this paper is limited to the structure of his semiotic model. We emphasize that Vygotsky`s model does not explicitly account for a hierarchy of multiple levels of semiotic analysis. His analysis regularly slips from one level to another: (1) a lever of cognitive perception by a regular reader is confused with a level of creative genius of a writer; (2) {open_quotes}open{close_quotes} time of real world is mixed up with {open_quote}closed{close_quote} time of the story; (3) events are not organized by the hierarchy of their importance, nor in real world, nor in the inner model of the personages, nor in the story.
Isostatic compensation of equatorial highlands on Venus
NASA Technical Reports Server (NTRS)
Kucinskas, Algis B.; Turcotte, Donald L.
1994-01-01
Spherical harmonic models for Venus' global topography and gravity incorporating Magellan data are used to test isostatic compensation models in five 30 deg x 30 deg regions representative of the main classes of equatorial highlands. The power spectral density for the harmonic models obeys a power-law scaling with spectral slope Beta approximately 2 (Brown noise) for the topography and Beta approximately 3 (Kaula's law) for the geoid, similar to what is observed for Earth. The Venus topography spectrum has lower amplitudes than Earth's which reflects the dominant lowland topography on Venus. Observed degree geoid to topography ratios (GTRs) on Venus are significantly smaller than degree GTRs for uncompensated topography, indicative of substantial compensation. Assuming a global Airy compensation, most of the topography is compensated at depths greater than 100 km, suggesting a thick lithosphere on Venus. For each region considered we obtain a regional degree of compensation C from a linear regression of Bouguer anomaly versus Bouguer gravity data. Geoid anomaly (N) versus topography variation (h) data for each sample were compared, in the least-squares sense, to theoretical correlations for Pratt, Airy, and thermal thinning isostasy models yielding regional GTR, zero-elevation crustal thickness (H), and zero elevation thermal lithosphere thickness (y(sub L(sub 0)), respectively. We find the regional compensation to be substantial (C approximately 52-80%), and the h, N data correlations in the chosen areas can be explained by isostasy models applicable on the Earth and involving variations in crustal thickness (Airy) and/or lithospheric (thermal thinning) thickness. However, a thick crust and lithosphere (y(sub L(sub 0)) approximately 300 km) must be assumed for Venus.
The discoveries of Neptune and Triton.
NASA Astrophysics Data System (ADS)
Moore, P.
The story of the tracking-down of Neptune has been told many times, but even today there are still discrepancies in the various accounts, to say nothing of conflicting opinions. To some people, John Couch Adams is a shining hero and George Biddell Airy a black villain; to others it is Le Verrier who is the hero, and Adams an unimportant member of the supporting cast. Of course, all this is absurd. In the author's view, the true discoverers of Neptune were Johann Gottfried Galle and Heinrich D'Arrest.
Quantitative void characterization in structural ceramics using scanning laser acoustic microscopy
NASA Technical Reports Server (NTRS)
Roth, D. J.; Generazio, E. R.; Baaklini, G. Y.
1986-01-01
The ability of scanning laser acoustic microscopy (SLAM) to characterize artificially seeded voids in sintered silicon nitride structural ceramic specimens was investigated. Using trigonometric relationships and Airy's diffraction theory, predictions of internal void depth and size were obtained from acoustic diffraction patterns produced by the voids. Agreement was observed between actual and predicted void depths. However, predicted void diameters were generally much greater than actual diameters. Precise diameter predictions are difficult to obtain due to measurement uncertainty and the limitations of 100 MHz SLAM applied to typical ceramic specimens.
NCI Holds on to Defelice Cup | Poster
NCI kept the Defelice Cup trophy this year after beating Leidos Biomedical Research, 15 to 9, at the 10th annual Ronald H. Defelice Golf Tournament held on Columbus Day. Sixteen players on each team battled it out at the yearly contractor vs. government tournament held at Rattlewood Golf Course in Mount Airy, Md. NCI leads the series 6–4. “The score was the highest NCI margin of victory in the 10-year series,” said Denny Dougherty, retired senior subcontracts advisor at what was formerly SAIC-Frederick. “The intensity of the annual competition has increased each year and has become...
Light steering of Air-Gaussian beam in Nonlocal Nonlinear Medium
NASA Astrophysics Data System (ADS)
Chen, Ran; Zhang, Xiaping
2016-07-01
With a nonlocal model, we investigate the propagation dynamics of a single Airy-Gaussian (AiG) beam and their interaction in one-dimensional condition by means of direct numerical simulations. With the split-step Fourier method, numerical results show that nonlocality can support periodic intensity distribution of AiG beams leading to the formation of stable bound states. Espesically, by tuning the phase difference between the two beams, we can steer the centre of the bound AiG beams in nonlocal nonlinear media.
1981-01-26
The final design of the Mount Airy Public Library is given. Incremental passive design costs are discussed. Performance and economic analyses are made and the results reported. The design process is thoroughly documented. Considerations discussed are: (1) building energy needs; (2) site energy potentials, (3) matching energy needs with site energy potentials, (4) design indicators for best strategies and concepts, (5) schematic design alternatives, (6) performance testing of the alternatives, (7) design selection, and (8) design development. Weather data and Duke Power electric rates are included. (LEW)
NASA Astrophysics Data System (ADS)
Niemi, Paul; McLeod, Roger
2006-03-01
Mc Leod predicts that in visual tasks with pupil diameter changes, a longer, quasimonochromatic wavelength interval is coincident with foveal cones, and rods. A shorter, partially overlapped interval separately aligns with extrafoveal cones. Wavelengths follow the Airy disk radius formula. Extended visual tasks of a type requiring shorter wavelengths, pair extrinsic eye muscles in inappropriate states, one in extension, the other in contraction, exceeding ``Hooke's law'' settings. Hysterisis prevents feedback-driven, self repair. The universal model for vision predicts myopia, hyperopia and presbyopia. Niemi can test and evaluate that model: repair needs triggering and facilitating demands of the possibly overridden feedback signals.
High-resolution phase imaging of phase singularities in the focal region of a lens
NASA Astrophysics Data System (ADS)
Walford, J. N.; Nugent, K. A.; Roberts, A.; Scholten, R. E.
2002-03-01
Subwavelength-resolution phase images of phase dislocations at the focal region of a 20×, 0.4-N.A. lens have been obtained by use of an optical fiber interferometer with a tapered probe in one arm. A phase-stepping algorithm is used to determine a quantitative value of the phase at each point in the scan, clearly showing the presence of edge dislocations between the Airy rings of the diffraction pattern near the lens focus, as well as four isolated screw-type singularties caused by astigmatism in the lens.
Surface-plasmon-coupled emission microscopy with a polarization converter.
Chen, Yikai; Zhang, Douguo; Han, Lu; Rui, Guanghao; Wang, Xiangxian; Wang, Pei; Ming, Hai
2013-03-01
Although surface-plasmon-coupled emission-based fluorescence microscopy proves high sensitivity for surface imaging, its donut shape point spread function (PSF) leads to low optical resolution and inefficient signal collection. In this Letter, we experimentally demonstrate the feasibility of solving this problem by the use of a liquid-crystal plate, which could convert the polarization state of surface-plasmon-coupled fluorescence from radial to linear. After being focused by the collection lens, an Airy disk-like PSF of small size can be realized. Experimental results reveal that both the lateral resolution and the signal-to-noise ratio can be enhanced simultaneously. PMID:23455282
Elastostatic bending of a bimaterial plate with a circular interface
NASA Astrophysics Data System (ADS)
Ogbonna, Nkem
2015-08-01
The elastostatic bending of an arbitrarily loaded bimaterial plate with a circular interface is analysed. It is shown that the deflections in the composite solid are directly related to the deflection in the corresponding homogeneous material by integral and differential operators. It is further shown that, by a simple transformation of elastic constants, the Airy stress function induced in the composite by a stretching singularity can be deduced from the deflection induced by a bending singularity. This result is significant for reduction of mathematical labour and for systematic construction of solutions for more complex structures with circular geometry.
Study of Rainbow Scattering in 16O + 14C System
NASA Astrophysics Data System (ADS)
Demyanova, A. S.; Glukhov, Yu. A.; Ogloblin, A. A.; Trzaska, W.; Bohlen, H. G.; Oertzen, W. Von; Goncharov, S. A.; Izadpanakh, A.; Maslov, V. A.; Penionzhkevich, Yu. E.; Sobolev, Yu. G.; Khlebnikov, S. V.; Tyurin, G. P.
2005-09-01
We carried out new measurements of the 16O+14C differential cross-sections at the 16O energy 281 MeV in the large angles interval at the Jyvaskyla University cyclotron and at the smallest angles at the cyclotron of Hahn-Meitner institute. The results of the experiment showed that clear rainbow structure in 16O + 14C scattering really takes place. The observed position of the main Airy minimum predicted but not observed in previous measurements fits well to the empirical systematization "angle - inverse energy", obtained for the system 16O + 12C.
Marchiano, Régis; Thomas, Jean-Louis; Coulouvrat, François
2003-10-31
An accelerating supersonic aircraft produces noisy superboom due to acoustical shock wave focusing at a fold caustic. This phenomenon is modeled by the mixed-type nonlinear Tricomi equation. An innovative experimental simulation in a water tank has been carried out, with perfect similitude to sonic boom in air. In the linear regime, the canonical Airy function is reproduced using the inverse filter technique. In the nonlinear regime (weak shock waves), the experiment demonstrates the key role of nonlinear effects: they limit the field amplitude, distort the sonic line, and strongly alter the phase of the signal, in agreement with numerical simulations. PMID:14611285
NASA Astrophysics Data System (ADS)
Bendahma, F.; Djelti, R.; Bentata, S.
2016-08-01
The aperiodic GaAs/AlxGa1-xAs superlattices (SL) with trimer disorder have been studied in this paper. The transfer-matrix technique and the exact Airy function formalism have been used to determine the miniband structure, the transmission coefficient, the resonance energy and resonant tunneling time (RTT). Although the disorder localizes the states on average, our numerical calculations show that the localization length of the states becomes more extended when the disorder is correlated (trimer case). We have also found that the RTT is of the order of several femtoseconds.
Wave tilt sounding of a linearly inhomogeneous layered half-space
NASA Technical Reports Server (NTRS)
Warne, L.; Evans, D.; Elachi, C.
1979-01-01
The wave tilt of a transverse electric (TE) electromagnetic wave over a linearly inhomogeneous lossy layer overlying a homogeneous half-space is studied. Two approaches are used: an exact formulation using solutions of Airy's equation and an approximate numerical solution using a large number of homogeneous layers with a linearly increasing dielectric constant. The numerical results of both solutions are practically identical as long as the thickness of the layers in the approximate model are somewhat smaller than a quarter-wave length.
Experimental realization of spectral shaping using nonlinear optical holograms.
Leshem, Anat; Shiloh, Roy; Arie, Ady
2014-09-15
We experimentally demonstrate the spectral shaping of a signal generated by a three-wave mixing process using a nonlinear spectral hologram. These holograms are based on binary spatial modulation of the second-order nonlinear coefficient. Here we present the first experimental realization, to the best of our knowledge, of this concept, encoding a nonlinear hologram in a KTiOPO(4) crystal by electric field poling. Two different spectra in the form of the second-order Hermite-Gauss function and the Airy function are shown using the sum-frequency generation process. PMID:26466274
Prediction of noise field of a propfan at angle of attack
NASA Technical Reports Server (NTRS)
Envia, Edmane
1991-01-01
A method for predicting the noise field of a propfan operating at an angle of attack to the oncoming flow is presented. The method takes advantage of the high-blade-count of the advanced propeller designs to provide an accurate and efficient formula for predicting their noise field. The formula, which is written in terms of the Airy function and its derivative, provides a very attractive alternative to the use of numerical integration. A preliminary comparison shows rather favorable agreement between the predictions from the present method and the experimental data.
Rejoice in the hubris: useful things biologists could do for physicists
NASA Astrophysics Data System (ADS)
Austin, Robert H.
2014-10-01
Political correctness urges us to state how wonderful it is to work with biologists and how, just as the lion will someday lie down with the lamb, so will interdisciplinary work, where biologists and physicists are mixed together in light, airy buildings designed to force socialization, give rise to wonderful new science. But it has been said that the only drive in human nature stronger than the sex drive is the drive to censor and suppress, and so I claim that it is OK for physicists and biologists to maintain a wary distance from each other, so that neither one censors or suppresses the wild ideas of the other.
Metrology system for the Terrestrial Planet Finder Coronagraph
NASA Technical Reports Server (NTRS)
Shaklin, Stuart; Marchen, Luis; Zhao, Feng; Peters, Robert D.; Ho, Tim; Holmes, Buck
2004-01-01
The Terrestrial Planet Finder (TPF) employs an aggressive coronagraph designed to obtain better than 1e-10 contrast inside the third Airy ring. Minute changes in low-order aberration content scatter significant light at this position. One implication is the requirement to control low-order aberrations induced by motion of the secondary mirror relative to the primary mirror; sub-nanometer relative positional stability is required. We propose a 6-beam laser truss to monitor the relative positions of the two mirrors. The truss is based on laser metrology developed for the Space Interferometry Mission.
Application of super smooth optics to extra-solar planet detection
NASA Technical Reports Server (NTRS)
Terrile, Richard J.; Ftaclas, Christ
1989-01-01
The observational constraints on direct detection of extrasolar planets around nearby stars are defined. The design of an instrument capable of meeting these goals requires the efficient reduction of diffracted and scattered light by about three orders of magnitude below the airy wings of the unapodized aperture. The diffraction reduction is achieved through the high-efficiency coronagraph, which uses Gaussian occulting masks in the first focus to concentrate better diffracted light in the pupil plane. Laboratory experiments confirm this high efficiency to the limits set by the experimental setup. Scattering due to midspatial scale figure error in the mirrors must also be reduced to a comparable level.
An Invariance Principle to Ferrari-Spohn Diffusions
NASA Astrophysics Data System (ADS)
Ioffe, Dmitry; Shlosman, Senya; Velenik, Yvan
2015-06-01
We prove an invariance principle for a class of tilted 1 + 1-dimensional SOS models or, equivalently, for a class of tilted random walk bridges in . The limiting objects are stationary reversible ergodic diffusions with drifts given by the logarithmic derivatives of the ground states of associated singular Sturm-Liouville operators. In the case of a linear area tilt, we recover the Ferrari-Spohn diffusion with log-Airy drift, which was derived in Ferrari and Spohn (Ann Probab 33(4):1302—1325, 2005) in the context of Brownian motions conditioned to stay above circular and parabolic barriers.
Comparison of interpolation methods for ISAR imaging
NASA Astrophysics Data System (ADS)
Vargas, Ricardo A.; Flores, Benjamin C.
1997-09-01
The purpose of this article is to describe and compare different numerical methods to reconstruct focused ISAR imagery via interpolation in either range-Doppler or frequency domains. Parameters such as amplitude deviation, image entropy, as well as computational efficiency are used to contrast the different approaches presented. It is shown that conventional linear and cubic interpolation techniques are less accurate than other weighted integration techniques, including the unified Fourier reconstruction algorithm which uses an Airy pattern as the interpolating kernel. The appearance of artifacts in linear and cubic interpolation methods is illustrated and discussed. A point target model of a navy drone is used to compare the effectiveness of each method.
Symmetry reductions, exact solutions, and conservation laws of the generalized Zakharov equations
NASA Astrophysics Data System (ADS)
Buhe, Eerdun; Bluman, George W.
2015-10-01
In this paper, the generalized Zakharov equations, which describe interactions between high- and low-frequency waves in plasma physics are studied from the perspective of Lie symmetry analysis and conservation laws. Based on some subalgebras of symmetries, several reductions and numerous new exact solutions are obtained. All of these solutions represent modified traveling waves. The obtained solutions include expressions involving Airy functions, Bessel functions, Whittaker functions, and generalized hypergeometric functions. Previously unknown conservation laws are constructed for the generalized Zakharov equations using the direct method. Profiles are presented for some of these new solutions.
NASA Astrophysics Data System (ADS)
Marchiano, Régis; Thomas, Jean-Louis; Coulouvrat, François
2003-10-01
An accelerating supersonic aircraft produces noisy superboom due to acoustical shock wave focusing at a fold caustic. This phenomenon is modeled by the mixed-type nonlinear Tricomi equation. An innovative experimental simulation in a water tank has been carried out, with perfect similitude to sonic boom in air. In the linear regime, the canonical Airy function is reproduced using the inverse filter technique. In the nonlinear regime (weak shock waves), the experiment demonstrates the key role of nonlinear effects: they limit the field amplitude, distort the sonic line, and strongly alter the phase of the signal, in agreement with numerical simulations.
Approximate Symmetry Reduction Approach: Infinite Series Reductions to the KdV-Burgers Equation
NASA Astrophysics Data System (ADS)
Jiao, Xiaoyu; Yao, Ruoxia; Zhang, Shunli; Lou, Sen Y.
2009-11-01
For weak dispersion and weak dissipation cases, the (1+1)-dimensional KdV-Burgers equation is investigated in terms of approximate symmetry reduction approach. The formal coherence of similarity reduction solutions and similarity reduction equations of different orders enables series reduction solutions. For the weak dissipation case, zero-order similarity solutions satisfy the Painlevé II, Painlevé I, and Jacobi elliptic function equations. For the weak dispersion case, zero-order similarity solutions are in the form of Kummer, Airy, and hyperbolic tangent functions. Higher-order similarity solutions can be obtained by solving linear variable coefficients ordinary differential equations.
Special modulated beams for cylindrical coordinates in anisotropic media using computer algebra
NASA Astrophysics Data System (ADS)
Echeverri Chacón, Santiago
2010-04-01
An extension of the solution for the propagation of modulated beams through homogeneous media in cylindrical coordinates which results in a wave function described by Bessel Beams is the basis for this analysis of modulated beams through non homogeneous media in cylindrical coordinates]. By solving the wave equation analytically, including functions that describe the non-homogeneity, and using computer algebra software such as MAPLE©, we formulate new kinds of beams defined by special functions such as Airy, Kummer,and Hypergeometric functions. We also present convergence issues around the axis of propagation and possible applications for these new beams in telecommunication systems.
NASA Astrophysics Data System (ADS)
Curtright, Thomas L.; Zachos, Cosmas K.
2013-10-01
In recent years the umbral calculus has emerged from the shadows to provide an elegant correspondence framework that automatically gives systematic solutions of ubiquitous difference equations --- discretized versions of the differential cornerstones appearing in most areas of physics and engineering --- as maps of well-known continuous functions. This correspondence deftly sidesteps the use of more traditional methods to solve these difference equations. The umbral framework is discussed and illustrated here, with special attention given to umbral counterparts of the Airy, Kummer, and Whittaker equations, and to umbral maps of solitons for the Sine-Gordon, Korteweg--de Vries, and Toda systems.
Evading the sign problem in the mean-field approximation through Lefschetz-thimble path integral
NASA Astrophysics Data System (ADS)
Tanizaki, Yuya; Nishimura, Hiromichi; Kashiwa, Kouji
2015-05-01
The fermion sign problem appearing in the mean-field approximation is considered, and the systematic computational scheme of the free energy is devised by using the Lefschetz-thimble method. We show that the Lefschetz-thimble method respects the reflection symmetry, which makes physical quantities manifestly real at any order of approximations using complex saddle points. The formula is demonstrated through the Airy integral as an example, and its application to the Polyakov-loop effective model of dense QCD is discussed in detail.
Transient thermal stress analysis of a laminated composite beam
Tanigawa, Y.; Murakami, H.; Ootao, Y. California Univ., La Jolla Osaka Prefectural Industrial Technology Research Institute )
1989-01-01
This paper considers a transient thermal stress analysis of a laminated beam made of different materials in multilayers. To simplify the problem, the heat conduction problem is treated as a one-dimensional case in the direction of thickness; then, the transient temperature solution is evaluated using the Laplace transform method. For the thermoelastic fields, thermal stress distributions are obtained using the elementary beam theory and Airy's thermal stress function method. As an example, numerical calculations are carried out for a laminated beam made of five layers, and the numerical results are examined.
Limitation on image resolution imposed by a random medium.
Ishimaru, A
1978-02-01
In underwater photography, it was reported that clear photographs were obtained through water with large (10-15) optical distances even though the MTF rolls off at a few cycles per mrad. This paper presents an explanation of this apparent contradiction by showing that at a large optical distance where the total coherent intensity is negligibly small compared with the total incoherent intensity, it is still possible to form the Airy disk due to the coherent intensity. We present the condition under which this can take place and applied the results to an imaging system in still water and in water with particulate matter. PMID:20174413
Improved coordinates of features in the vicinity of the Viking lander site on Mars
NASA Technical Reports Server (NTRS)
Davies, M. E.; Dole, S. H.
1980-01-01
The measurement of longitude of the Viking 1 landing site and the accuracy of the coordinates of features in the area around the landing site are discussed. The longitude must be measured photogrammatically from the small crater, Airy 0, which defines the 0 deg meridian on Mars. The computer program, GIANT, which was used to perform the analytical triangulations, and the photogrammetric computation of the longitude of the Viking 1 lander site are described. Improved coordinates of features in the vicinity of the Viking 1 lander site are presented.
Leaky modes of curved long-range surface plasmon-polariton waveguide
NASA Astrophysics Data System (ADS)
Kim, Woo-Kyung; Yang, Woo-Seok; Lee, Hyung-Man; Lee, Han-Young; Lee, Myung-Hyun; Jung, Woo-Jin
2006-12-01
A three-dimensional method for obtaining the bending losses and field distributions of bent surface plamon-polariton waveguides is presented. The method is based on a so called ‘method of line’, which discretises potential in the direction of the metal-widths, and leads to Airy-equations in the radial direction. From the results obtained. It is confirmed that thiner metal waveguide enable longer-ranging propagation of surface plasmon-polariton mode, but the weakened confinement requires larger bending radii on order to keep radiation loss.
Gap plasmon resonator arrays for unidirectional launching and shaping of surface plasmon polaritons
NASA Astrophysics Data System (ADS)
Lei, Zeyu; Yang, Tian
2016-04-01
We report the design and experimental realization of a type of miniaturized device for efficient unidirectional launching and shaping of surface plasmon polaritons (SPPs). Each device consists of an array of evenly spaced gap plasmon resonators with varying dimensions. Particle swarm optimization is used to achieve a theoretical two-dimensional launching efficiency of about 51%, under the normal illumination of a 5-μm waist Gaussian beam at 780 nm. By modifying the wavefront of the SPPs, unidirectional SPPs with focused, Bessel, and Airy profiles are launched and imaged with leakage radiation microscopy.
Holonomy, quantum mechanics and the signal-tuned Gabor approach to the striate cortex
NASA Astrophysics Data System (ADS)
Torreão, José R. A.
2016-02-01
It has been suggested that an appeal to holographic and quantum properties will be ultimately required for the understanding of higher brain functions. On the other hand, successful quantum-like approaches to cognitive and behavioral processes bear witness to the usefulness of quantum prescriptions as applied to the analysis of complex non-quantum systems. Here, we show that the signal-tuned Gabor approach for modeling cortical neurons, although not based on quantum assumptions, also admits a quantum-like interpretation. Recently, the equation of motion for the signal-tuned complex cell response has been derived and proven equivalent to the Schrödinger equation for a dissipative quantum system whose solutions come under two guises: as plane-wave and Airy-packet responses. By interpreting the squared magnitude of the plane-wave solution as a probability density, in accordance with the quantum mechanics prescription, we arrive at a Poisson spiking probability — a common model of neuronal response — while spike propagation can be described by the Airy-packet solution. The signal-tuned approach is also proven consistent with holonomic brain theories, as it is based on Gabor functions which provide a holographic representation of the cell’s input, in the sense that any restricted subset of these functions still allows stimulus reconstruction.
Biological aerosol detection with combined passive-active infrared measurements
NASA Astrophysics Data System (ADS)
Ifarraguerri, Agustin I.; Vanderbeek, Richard G.; Ben-David, Avishai
2004-12-01
A data collection experiment was performed in November of 2003 to measure aerosol signatures using multiple sensors, all operating in the long-wave infrared. The purpose of this data collection experiment was to determine whether combining passive hyperspectral and LIDAR measurements can substantially improve biological aerosol detection performance. Controlled releases of dry aerosols, including road dust, egg albumin and two strains of Bacillus Subtilis var. Niger (BG) spores were performed using the ECBC/ARTEMIS open-path aerosol test chamber located in the Edgewood Area of Aberdeen Proving Grounds, MD. The chamber provides a ~ 20' path without optical windows. Ground truth devices included 3 aerodynamic particle sizers, an optical particle size spectrometer, 6 nephelometers and a high-volume particle sampler. Two sensors were used to make measurements during the test: the AIRIS long-wave infrared imaging spectrometer and the FAL CO2 LIDAR. The AIRIS and FAL data sets were analyzed for detection performance relative to the ground truth. In this paper we present experimental results from the individual sensors as well as results from passive-active sensor fusion. The sensor performance is presented in the form of receiver operating characteristic curves.
Assessment of a multibeam Fizeau wedge interferometer for Doppler wind lidar.
McKay, Jack A
2002-03-20
The Fabry-Perot interferometer is the standard instrument for the direct detection Doppler lidar measurement of atmospheric wind speeds. The multibeam Fizeau wedge has some practical advantages over the Fabry-Perot, such as the linear fringe pattern, and is evaluated for this application. The optimal Fizeau must have a resolving power of 10(6) or more. As the multibeam Fizeau wedge is pushed to such high resolving power, the interference fringes of the device become complicated by asymmetry and secondary maxima. A simple condition for the interferometer plate reflectance, optical gap, and wedge angle reveals whether a set of parameters will yield simple, Airy-like fringes or complex Fizeau fringes. Tilting of the Fizeau wedge improves the fringe shape and permits an extension of the regime of Airy-like fringes to higher resolving power. Sufficient resolving power for the wind lidar application is shown to be possible with a large-gap, low-finesse multibeam Fizeau wedge. Liabilities of the multibeam Fizeau wedge in the wind lidar application include a smaller acceptance solid angle and calibration sensitivity to localized deviations of the plates from the ideal. PMID:11921807
Improved detection and false alarm rejection for chemical vapors using passive hyperspectral imaging
NASA Astrophysics Data System (ADS)
Marinelli, William J.; Miyashiro, Rex; Gittins, Christopher M.; Konno, Daisei; Chang, Shing; Farr, Matt; Perkins, Brad
2013-05-01
Two AIRIS sensors were tested at Dugway Proving Grounds against chemical agent vapor simulants. The primary objectives of the test were to: 1) assess performance of algorithm improvements designed to reduce false alarm rates with a special emphasis on solar effects, and 3) evaluate performance in target detection at 5 km. The tests included 66 total releases comprising alternating 120 kg glacial acetic acid (GAA) and 60 kg triethyl phosphate (TEP) events. The AIRIS sensors had common algorithms, detection thresholds, and sensor parameters. The sensors used the target set defined for the Joint Service Lightweight Chemical Agent Detector (JSLSCAD) with TEP substituted for GA and GAA substituted for VX. They were exercised at two sites located at either 3 km or 5 km from the release point. Data from the tests will be presented showing that: 1) excellent detection capability was obtained at both ranges with significantly shorter alarm times at 5 km, 2) inter-sensor comparison revealed very comparable performance, 3) false alarm rates < 1 incident per 10 hours running time over 143 hours of sensor operations were achieved, 4) algorithm improvements eliminated both solar and cloud false alarms. The algorithms enabling the improved false alarm rejection will be discussed. The sensor technology has recently been extended to address the problem of detection of liquid and solid chemical agents and toxic industrial chemical on surfaces. The phenomenology and applicability of passive infrared hyperspectral imaging to this problem will be discussed and demonstrated.
NASA Technical Reports Server (NTRS)
Haxby, W. F.; Turcotte, D. L.
1978-01-01
In regions of slowly varying lateral density changes, the gravity and geoid anomalies may be expressed as power series expansions in topography. Geoid anomalies in isostatically compensated regions can be directly related to the local dipole moment of the density-depth distribution. This relationship is used to obtain theoretical geoid anomalies for different models of isostatic compensation. The classical Pratt and Airy models give geoid height-elevation relationships differing in functional form but predicting geoid anomalies of comparable magnitude. The thermal cooling model explaining ocean floor subsidence away from mid-ocean ridges predicts a linear age-geoid height relationship of 0.16 m/m.y. Geos 3 altimetry profiles were examined to test these theoretical relationships. A profile over the mid-Atlantic ridge is closely matched by the geoid curve derived from the thermal cooling model. The observed geoid anomaly over the Atlantic margin of North America can be explained by Airy compensation. The relation between geoid anomaly and bathymetry across the Bermuda Swell is consistent with Pratt compensation with a 100-km depth of compensation.
Fabrication and testing of a silicon immersion grating for infrared spectroscopy
Kuzmenko, P.J.; Ciarlo, D.R.; Stevens, C.G.
1994-07-25
Recent advances in silicon micromachining techniques (e.g. anisotropic etching) allow the fabrication of very coarse infrared echelle gratings. When used in immersion mode, the dispersion is increased proportionally to the refractive index. This permits a very significant reduction in the overall size of a spectrometer while maintaining the same resolution. We have fabricated a right triangular prism (30{times}60{times}67 mm with a rectangular entrance face 30{times}38 mm) from silicon with a grating etched into the face of the hypotenuse. The grating covers an area of 32 mm by 64 mm and has a 97.5 PM periodicity with a blaze angle of 63.4{sup o}. The groove surfaces are very smooth with a roughness of a few manometers. Random defects in the silicon are the dominant source of grating scatter ({approx} 12% at 3.39 {mu}m). We measure a grating ghost intensity of 1.2%. The diffraction peak is quite narrow, slightly larger than the Airy disc diameter at F/12. However due to wavefront aberrations, perhaps 15--20% of the diffracted power is in the peak with the rest distributed in a diameter roughly five times the Airy disc.
Isotropic 3D Super-resolution Imaging with a Self-bending Point Spread Function
Jia, Shu; Vaughan, Joshua C.; Zhuang, Xiaowei
2014-01-01
Airy beams maintain their intensity profiles over a large propagation distance without substantial diffraction and exhibit lateral bending during propagation1-5. This unique property has been exploited for micromanipulation of particles6, generation of plasma channels7 and guidance of plasmonic waves8, but has not been explored for high-resolution optical microscopy. Here, we introduce a self-bending point spread function (SB-PSF) based on Airy beams for three-dimensional (3D) super-resolution fluorescence imaging. We designed a side-lobe-free SB-PSF and implemented a two-channel detection scheme to enable unambiguous 3D localization of fluorescent molecules. The lack of diffraction and the propagation-dependent lateral bending make the SB-PSF well suited for precise 3D localization of molecules over a large imaging depth. Using this method, we obtained super-resolution imaging with isotropic 3D localization precision of 10-15 nm over a 3 μm imaging depth from ∼2000 photons per localization. PMID:25383090
Altimetry data and the elastic stress tensor of subduction zones
NASA Technical Reports Server (NTRS)
Caputo, M.
1985-01-01
The stress field in the lithosphere caused by the distribution of density anomalies associated to the geoidal undulations observed by the GEOS-3 and SEASAT Earth satellites in the Tonga region was studied. Different models of the lithosphere were generated with different assumptions on the density distribution and geometry, all generating a geoid profile almost identical to the observed one. The first model is the Airy isostatic hypothesis which consists of a crust of density 2.85 laying on a lithosphere of density 3.35. The models obtained with different compensation depths give residual shortwavelength anomalies of the order of several tens of mgal and several tens of meters geoidal undulations. It indicates that there is no isostasy of the Airy type in the Tonga region because the observed geoid has very smooth undulation of about 25 m over a distance of 2000 km. The Pratt isostatic hypothesis is used in a model consisting of a crust of variable density laying on a lithosphere of higher density. This model gives smaller residual anomalies but still shows that there is no isostasy of the Pratt type in the Tonga region because the observed geoidal undulation are much smaller and smoother than the residual undulations associated to the Pratt model of isostasy.
A phase-space approach for propagating field-field correlation functions
NASA Astrophysics Data System (ADS)
Gradoni, Gabriele; Creagh, Stephen C.; Tanner, Gregor; Smartt, Christopher; Thomas, David W. P.
2015-09-01
We show that radiation from complex and inherently random but correlated wave sources can be modelled efficiently by using an approach based on the Wigner distribution function. Our method exploits the connection between correlation functions and the Wigner function and admits in its simplest approximation a direct representation in terms of the evolution of ray densities in phase space. We show that next leading order corrections to the ray-tracing approximation lead to Airy-function type phase space propagators. By exploiting the exact Wigner function propagator, inherently wave-like effects such as evanescent decay or radiation from more heterogeneous sources as well as diffraction and reflection can be included and analysed. We discuss in particular the role of evanescent waves in the near-field of non-paraxial sources and give explicit expressions for the growth rate of the correlation length as a function of the distance from the source. The approximations are validated using full-wave simulations of model sources. In particular, results for the reflection of partially coherent sources from flat mirrors are given where the influence of Airy function corrections can be demonstrated. We focus here on electromagnetic sources at microwave frequencies and modelling efforts in the context of electromagnetic compatibility.
Far fields of internal gravity waves at arbitrary movement speeds of source of disturbances
NASA Astrophysics Data System (ADS)
Bulatov, V. V.; Vladimirov, Yu. V.
2015-11-01
The problem of a far field of internal gravity waves excited by a moving source of disturbances in a stratified medium is considered. The uniform asymptotics describing the amplitude-phase structure of the wave fields for the different conditions of a source movement are constructed. The wave pattern, including the position of a front, under subcritical conditions of source movement is determined by waves with the wave numbers restricted by a certain positive value from below, whereas under supercritical conditions the wave pattern is formed by the waves of all ranges and the front is determined only by long waves. In the first case, the phase portrait represents longitudinal and transverse waves decaying as a power function; in the second case, it is formed only of longitudinal waves decaying exponentially. In the first case, the uniform asymptotics of the far field consists of two terms, one of which is represented by the Airy function and the second is represented by its derivative; in the second case, the asymptotics has only one term that is expressed through the Airy function.
Time-domain model for TLP surge response in extreme sea states
Finnigan, T.D.; Botelho, D.L.R.; Petrauskas, C.
1984-05-01
A time-domain model is presented and evaluated for the prediction of the surge response of a tension leg platform (TLP) in regular and random waves, in the presence of a current. The wave force equation in the model is a modification of the Morison equation. Wave diffraction effects are incorporated in an approximate manner. The time-domain model is evaluated on the basis of experimental tests that were performed on a 1:60 scale model of a TLP. The tests were specially designed to investigate the effect of combined waves and current on surge response. The tests were conducted in regular, random and grouped waves. Current was simulated by towing the model. Two different forms of linear wave theory based on stretching and extrapolating wave particle kinematics from Airy wave theory up to the free surface are investigated. The maximum surge response is predicted well by the time-domain model provided the extrapolation of Airy wave theory is used.
Noor, Fatimah A. Iskandar, Ferry; Abdullah, Mikrajuddin; Khairurrijal
2015-04-16
In this paper, we discuss the electron transmittance and tunneling current in high-k-based-MOS capacitors with trapping charge by including the off-diagonal effective-mass tensor elements and the effect of coupling between transverse and longitudinal energies represented by an electron velocity in the gate. The HfSiO{sub x}N/SiO{sub 2} dual ultrathin layer is used as the gate oxide in an n{sup +} poly- Si/oxide/Si capacitor to replace SiO{sub 2}. The main problem of using HfSiO{sub x}N is the charge trapping formed at the HfSiO{sub x}N/SiO{sub 2} interface that can influence the performance of the device. Therefore, it is important to develop a model taking into account the presence of electron traps at the HfSiO{sub x}N/SiO{sub 2} interface in the electron transmittance and tunneling current. The transmittance and tunneling current in n{sup +} poly- Si/HfSiO{sub x}N/trap/SiO2/Si(100) capacitors are calculated by using Airy wavefunctions and a transfer matrix method (TMM) as analytical and numerical approaches, respectively. The transmittance and tunneling current obtained from the Airy wavefunction are compared to those computed by the TMM. The effects of the electron velocity on the transmittance and tunneling current are also discussed.
Diffraction of acoustic-gravity waves in the presence of a turning point.
Godin, Oleg A
2016-07-01
Acoustic-gravity waves (AGWs) in an inhomogeneous atmosphere often have caustics, where the ray theory predicts unphysical, divergent values of the wave amplitude and needs to be modified. Unlike acoustic waves and gravity waves in incompressible fluids, AGW fields in the vicinity of a caustic have never been systematically studied. Here, asymptotic expansions of acoustic gravity waves are derived in the presence of a turning point in a horizontally stratified, moving fluid such as the atmosphere. Sound speed and the background flow (wind) velocity are assumed to vary gradually with height, and slowness of these variations determines the large parameter of the problem. It is found that uniform asymptotic expansions of the wave field in the presence of a turning point can be expressed in terms of the Airy function and its derivative. The geometrical, or Berry, phase, which arises in the consistent Wentzel-Kramers-Brillouin approximation for AGWs, plays an important role in the caustic asymptotics. In the dominant term of the uniform asymptotic solution, the terms with the Airy function and its derivative are weighted by the cosine and sine of the Berry phase, respectively. The physical meaning and corollaries of the asymptotic solutions are discussed. PMID:27475153
Universal asymptotic statistics of maximal relative height in one-dimensional solid-on-solid models
NASA Astrophysics Data System (ADS)
Schehr, Grégory; Majumdar, Satya N.
2006-05-01
We study the probability density function P(hm,L) of the maximum relative height hm in a wide class of one-dimensional solid-on-solid models of finite size L . For all these lattice models, in the large- L limit, a central limit argument shows that, for periodic boundary conditions, P(hm,L) takes a universal scaling form P(hm,L)˜(12wL)-1f(hm/(12wL)) , with wL the width of the fluctuating interface and f(x) the Airy distribution function. For one instance of these models, corresponding to the extremely anisotropic Ising model in two dimensions, this result is obtained by an exact computation using the transfer matrix technique, valid for any L>0 . These arguments and exact analytical calculations are supported by numerical simulations, which show in addition that the subleading scaling function is also universal, up to a nonuniversal amplitude, and simply given by the derivative of the Airy distribution function f'(x) .
NASA Astrophysics Data System (ADS)
Eliasson, B.; Milikh, G.; Shao, X.; Mishin, E. V.; Papadopoulos, K.
2015-04-01
We have numerically investigated the development of strong Langmuir turbulence (SLT) and associated electron acceleration at different angles of incidence of ordinary (O) mode pump waves. For angles of incidence within the Spitze cone, the turbulence initially develops within the first maximum of the Airy pattern near the plasma resonance altitude. After a few milliseconds, the turbulent layer shifts downwards by about 1 km. For injections outside the Spitze region, the turning point of the pump wave is at lower altitudes. Yet, an Airy-like pattern forms here, and the turbulence development is quite similar to that for injections within the Spitze. SLT leads to the acceleration of 10-20 eV electrons that ionize the neutral gas thereby creating artificial ionospheric layers. Our numerical modeling shows that most efficient electron acceleration and ionization occur at angles between the magnetic and geographic zenith, where SLT dominates over weak turbulence. Possible effects of the focusing of the electromagnetic beam on magnetic field-aligned density irregularities and the finite heating beam width at the magnetic zenith are also discussed. The results have relevance to ionospheric heating experiments using ground-based, high-power radio transmitters to heat the overhead plasma, where recent observations of artificial ionization layers have been made.
Rainbow-shift mechanism behind discrete optical-potential ambiguities
Brandan, M.E. ); McVoy, K.W. )
1991-03-01
Some years ago, Drisko {ital et} {ital al}. suggested that the discrete ambiguity often encountered for elastic scattering optical potentials could be understood as being due to the interior or small-{ital l} {ital S}-matrix elements for two equivalent'' potentials differing in phase by 2{pi}, {ital l}-by-{ital l}. We point out that the {ital absence} of this phase change for peripheral partial waves is equally essential, and suggest that a deeper understanding of the ambiguity may be achieved by viewing it as a consequence of a farside interference between interior and peripheral partial waves. It is this interference which produces the broad Airy maxima'' of a nuclear rainbow, and we show that a Drisko-type phase-shift increment {delta}{sub {ital l}}{r arrow}({delta}{sub {ital l}}+{pi}) for low-{ital l} phases relative to the high-{ital l} ones is exactly what is needed to shift a farside rainbow pattern by one Airy maximum, thus providing an equivalent rainbow-shift'' interpretation of the discrete ambiguity. The physical importance of both interpretations lies in the fact that the existence of discrete ambiguities (as well as of nuclear rainbows) is explicit evidence for low-{ital l} transparency in nucleus-nucleus collisions. The essential role played by low partial waves explains why peripheral reactions have generally not proven helpful in resolving this ambiguity.
Cheng, Jiyi; Gu, Chenglin; Zhang, Dapeng; Chen, Shih-Chi
2015-11-01
In this Letter, we present a digital micromirror device (DMD)-based ultrafast beam shaper, i.e., DUBS. To our knowledge, the DUBS is the first binary laser beam shaper that can generate high-resolution (1140×912 pixels) arbitrary beam modes for femtosecond lasers at a rate of 4.2 kHz; the resolution and pattern rate are limited by the DMD. In the DUBS, the spectrum of the input pulsed laser is first angularly dispersed by a transmission grating and subsequently imaged to a DMD with beam modulation patterns; the transmission grating and a high-reflectivity mirror together compensate the angular dispersion introduced by the DMD. The mode of the output beam is monitored by a CCD camera. In the experiments, the DUBS is programmed to generate four different beam modes, including an Airy beam, Bessel beam, Laguerre-Gaussian (LG) beam, and a custom-designed "peace-dove" beam via the principle of binary holography. To verify the high shaping rate, the Airy beam and LG beam are generated alternately at 4.2 kHz, i.e., the maximum pattern rate of our DMD. The overall efficiency of the DUBS is measured to be 4.7%. With the high-speed and high-resolution beam-shaping capability, the DUBS may find important applications in nonlinear microscopy, optical manipulation, and microscale/nanoscale laser machining, etc. PMID:26512472
Proceedings from the 6th Annual University of Calgary Leaders in Medicine Research Symposium.
Roberts, Jodie I; Beatty, Jennifer K; Peplowski, Michael A; Keough, Michael B; Yipp, Bryan G; Hollenberg, Morley D; Beck, Paul L
2015-01-01
On November 14, 2014, the Leaders in Medicine (LIM) program at the Cumming School of Medicine, University of Calgary hosted its 6th Annual Research Symposium. Dr. Danuta Skowronski, Epidemiology Lead for Influenza and Emerging Respiratory Pathogens at the British Columbia Centre for Disease Control (BCCDC), was the keynote speaker and presented a lecture entitled "Rapid response research during emerging public health crises: influenza and reflections from the five year anniversary of the 2009 pandemic". The LIM symposium provides a forum for both LIM and non-LIM medical students to present their research work, either as an oral or poster presentation. There were a total of six oral presentations and 77 posters presented. The oral presentations included: Swathi Damaraju, "The role of cell communication and 3D Cell-Matrix environment in a stem cell-based tissue engineering strategy for bone repair"; Menglin Yang, "The proteolytic activity of Nepenthes pitcher fluid as a therapeutic for the treatment of celiac disease"; Amelia Kellar, "Monitoring pediatric inflammatory bowel disease - a retrospective analysis of transabdominal ultrasound"; Monica M. Faria-Crowder, "The design and application of a molecular profiling strategy to identify polymicrobial acute sepsis infections"; Waleed Rahmani, "Hair follicle dermal stem cells regenerate the dermal sheath, repopulate the dermal papilla and modulate hair type"; and, Laura Palmer, "A novel role for amyloid beta protein during hypoxia/ischemia". The article on the University of Calgary Leaders in Medicine Program, "A Prescription that Addresses the Decline of Basic Science Education in Medical School," in a previous issue of CIM (2014 37(5):E292) provides more details on the program. Briefly, the LIM Research Symposium has the following objectives: (1) to showcase the impressive variety of projects undertaken by students in the LIM Program as well as University of Calgary medical students; (2) to encourage medical
The Glacial BuzzSaw, Isostasy, and Global Crustal Models
NASA Astrophysics Data System (ADS)
Levander, A.; Oncken, O.; Niu, F.
2015-12-01
The glacial buzzsaw hypothesis predicts that maximum elevations in orogens at high latitudes are depressed relative to temperate latitudes, as maximum elevation and hypsography of glaciated orogens are functions of the glacial equilibrium line altitude (ELA) and the modern and last glacial maximum (LGM) snowlines. As a consequence crustal thickness, density, or both must change with increasing latitude to maintain isostatic balance. For Airy compensation crustal thickness should decrease toward polar latitudes, whereas for Pratt compensation crustal densities should increase. For similar convergence rates, higher latitude orogens should have higher grade, and presumably higher density rocks in the crustal column due to more efficient glacial erosion. We have examined a number of global and regional crustal models to see if these predictions appear in the models. Crustal thickness is straightforward to examine, crustal density less so. The different crustal models generally agree with one another, but do show some major differences. We used a standard tectonic classification scheme of the crust for data selection. The globally averaged orogens show crustal thicknesses that decrease toward high latitudes, almost reflecting topography, in both the individual crustal models and the models averaged together. The most convincing is the western hemisphere cordillera, where elevations and crustal thicknesses decrease toward the poles, and also toward lower latitudes (the equatorial minimum is at ~12oN). The elevation differences and Airy prediction of crustal thickness changes are in reasonable agreement in the North American Cordillera, but in South America the observed crustal thickness change is larger than the Airy prediction. The Alpine-Himalayan chain shows similar trends, however the strike of the chain makes interpretation ambiguous. We also examined cratons with ice sheets during the last glacial period to see if continental glaciation also thins the crust toward
Further insight into the tunneling contribution to the vibrational relaxation of NO in Ar.
Dashevskaya, E I; Litvin, I; Nikitin, E E; Troe, J
2015-04-28
Tunneling corrections to Landau-Zener rate coefficients for the vibrational relaxation NO(X(2)Π, v = 1) + Ar → NO(X(2)Π, v = 0) + Ar between 300 and 2000 K are determined employing ab initio potential energy surfaces calculated by the code provided by Alexander [J. Chem. Phys. 111, 7426 (1999)]. The calculations use a reaction coordinate approach and lead to vibronically nonadiabatic transition probabilities within the generalized Airy approximation as extended to the WKB underbarrier Landau-Lifshitz limit. The calculations confirm experimental evidence for an onset of major tunneling contributions to the relaxation rate at temperatures below about 900 K and rationalize large tunneling contributions at 300 K. These effects increase the rate coefficients by several orders of magnitude over the uncorrected Landau-Zener values and remove the large gap between the latter and experimental results. PMID:25933767
Further insight into the tunneling contribution to the vibrational relaxation of NO in Ar
NASA Astrophysics Data System (ADS)
Dashevskaya, E. I.; Litvin, I.; Nikitin, E. E.; Troe, J.
2015-04-01
Tunneling corrections to Landau-Zener rate coefficients for the vibrational relaxation NO(X2Π, v = 1) + Ar → NO(X2Π, v = 0) + Ar between 300 and 2000 K are determined employing ab initio potential energy surfaces calculated by the code provided by Alexander [J. Chem. Phys. 111, 7426 (1999)]. The calculations use a reaction coordinate approach and lead to vibronically nonadiabatic transition probabilities within the generalized Airy approximation as extended to the WKB underbarrier Landau-Lifshitz limit. The calculations confirm experimental evidence for an onset of major tunneling contributions to the relaxation rate at temperatures below about 900 K and rationalize large tunneling contributions at 300 K. These effects increase the rate coefficients by several orders of magnitude over the uncorrected Landau-Zener values and remove the large gap between the latter and experimental results.
NASA Astrophysics Data System (ADS)
Berry, M. V.
2005-01-01
By applying the technique of uniform asymptotic approximation to the oscillatory integrals representing tsunami wave profiles, the form of the travelling wave far from the source is calculated for arbitrary initial disturbances. The approximations reproduce the entire profiles very accurately, from the front to the tail, and their numerical computation is much faster than that of the oscillatory integrals. For one-dimensional propagation, the uniform asymptotics involve Airy functions and their derivatives; for two-dimensional propagation, the uniform asymptotics involve products of these functions. Separate analyses are required when the initial disturbance is specified as surface elevation or surface velocity as functions of position, and when these functions are even or odd. 'There was an awful rainbow once in heaven' (John Keats, 1820)
Thermally induced optical nonlinearity during transient heating of thin films
Chen, G. ); Tien, C.L. )
1994-05-01
This work studies the temperature field and the optical response of weakly absorbing thin films with thermally induced optical nonlinearity during picosecond to nanosecond pulsed-laser heating. A one-dimensional model is presented that examines the effects of the temperature dependent optical constants and the nonuniform absorption caused by interference. The energy equation is solved numerically, coupled with the matrix method in optical multilayer theory. Both cadmium sulfide (CdS) thin films and a zinc selenide (ZnSe) interference filter are considered. The computational results compare favorably with available experimental data on the ZnSe interference filter. This study shows that the transient temperature distributions in the films are highly nonuniform. Such nonuniformity yields Airy's formulae for calculating the thin-film reflectance and transmittance inapplicable. Applications of the work include optical bistability, localized change of the film structure, and measurement of the thermal diffusivity of thin films. 31 refs., 7 figs., 1 tab.
Effect of water deposition on the surface dynamics of mesopores in MCM-41
NASA Astrophysics Data System (ADS)
Sobieszczyk, Paweł; Pajzderska, Aleksandra; Kuźma, Dominika; Majka, Marcin; Zieliński, Piotr
2016-04-01
The surface acoustic waves in empty cylindrical pores in the amorphous silica MCM-41 as well as in the same pores partially filled with water are studied with the use of a continuum model. The model is shown to be adequate to predict dispersion relations, cut-off wave vectors and the Airy phases for the secular surface waves of the lowest azimuthal indices n. Quantitative predictions are presented both in the liquid and in the polycrystalline solid phase of water. Two sagittal surface waves exist when water is in the liquid phase. The phase transition to the solid phase (ice) results in the disappearance of the high-frequency mode. All the effects occur in the Terahertz frequency region.
Diffraction-limited 10 microns imaging with 3 meter telescopes
NASA Technical Reports Server (NTRS)
Bloemhof, E. E.; Townes, C. H.; Vanderwyck, A. H. B.
1986-01-01
An IR imaging system that achieves diffraction-limited spatial resolution (about 0.8 arcsec) at 10 microns on 3-meter ground-based telescopes. The system uses a linear array of sensitive HgCdTe photodiodes, scanned in the direction perpendicular to the array axis, to form two-dimensional images. Scans are completed rapidly enough to freeze atmospheric fluctuations. Individual detectors are small compared to the diameter of the Airy disk, and images are oversampled heavily in the scan direction. This method has a number of advantages for studying small fields with very high spatial resolution, and has been applied successfully to the problem of directly imaging faint circumstellar dust shells.
Strehl-constrained iterative blind deconvolution for post-adaptive-optics data
NASA Astrophysics Data System (ADS)
Desiderà, G.; Carbillet, M.
2009-12-01
Aims: We aim to improve blind deconvolution applied to post-adaptive-optics (AO) data by taking into account one of their basic characteristics, resulting from the necessarily partial AO correction: the Strehl ratio. Methods: We apply a Strehl constraint in the framework of iterative blind deconvolution (IBD) of post-AO near-infrared images simulated in a detailed end-to-end manner and considering a case that is as realistic as possible. Results: The results obtained clearly show the advantage of using such a constraint, from the point of view of both performance and stability, especially for poorly AO-corrected data. The proposed algorithm has been implemented in the freely-distributed and CAOS-based Software Package AIRY.
On the Mass Distribution of Animal Species
NASA Astrophysics Data System (ADS)
Redner, Sidney; Clauset, Aaron; Schwab, David
2009-03-01
We develop a simple diffusion-reaction model to account for the broad and asymmetric distribution of adult body masses for species within related taxonomic groups. The model assumes three basic evolutionary features that control body mass: (i) a fixed lower limit that is set by metabolic constraints, (ii) a species extinction risk that is a weakly increasing function of body mass, and (iii) cladogenetic diffusion, in which daughter species have a slight tendency toward larger mass. The steady-state solution for the distribution of species masses in this model can be expressed in terms of the Airy function. This solution gives mass distributions that are in good agreement with data on 4002 terrestrial mammal species from the late Quaternary and 8617 extant bird species.
Controlling the spin-torque efficiency with ferroelectric barriers
NASA Astrophysics Data System (ADS)
Useinov, A.; Chshiev, M.; Manchon, A.
2015-02-01
Nonequilibrium spin-dependent transport in magnetic tunnel junctions comprising a ferroelectric barrier is theoretically investigated. The exact solutions of the free electron Schrödinger equation for electron tunneling in the presence of interfacial screening are obtained by combining Bessel and Airy functions. We demonstrate that the spin transfer torque efficiency, and more generally the bias dependence of tunneling magneto- and electroresistance, can be controlled by switching the ferroelectric polarization of the barrier. In particular, the critical voltage at which the in-plane torque changes sign can be strongly enhanced or reduced depending on the direction of the ferroelectric polarization of the barrier. This effect provides a supplementary way to electrically control the current-driven dynamic states of the magnetization and related magnetic noise in spin transfer devices.
Heat trap - An optimized far infrared field optics system. [for astronomical sources
NASA Technical Reports Server (NTRS)
Harper, D. A.; Hildebrand, R. H.; Winston, R.; Stiening, R.
1976-01-01
The article deals with the design and performance of a heat trap IR system designed to maximize the concentration and efficient reception of far IR and submillimeter wavelength radiation. The test object is assumed to be extended and/or viewed at wavelengths much longer than the detector, and the entrance aperture is limited to the size of the telescope Airy diffraction disk. The design of lenses, cavity, bolometers, light collectors, and mirrors for the system is discussed. Advantages and feasibility of arrays of heat traps are considered. Beam patterns, flux concentration, and performance variation with wavelength are dealt with. The heat trap is recommended for sensing all types of far IR sources and particularly for extended far IR sources.-
Morris, C M; Valdés Aguilar, R; Ghosh, A; Koohpayeh, S M; Krizan, J; Cava, R J; Tchernyshyov, O; McQueen, T M; Armitage, N P
2014-04-01
Kink bound states in the one-dimensional ferromagnetic Ising chain compound CoNb2O6 have been studied using high-resolution time-domain terahertz spectroscopy in zero applied magnetic field. When magnetic order develops at low temperature, nine bound states of kinks become visible. Their energies can be modeled exceedingly well by the Airy function solutions to a 1D Schrödinger equation with a linear confining potential. This sequence of bound states terminates at a threshold energy near 2 times the energy of the lowest bound state. Above this energy scale we observe a broad feature consistent with the onset of the two particle continuum. At energies just below this threshold we observe a prominent excitation that we interpret as a novel bound state of bound states--two pairs of kinks on neighboring chains. PMID:24745454
NASA Astrophysics Data System (ADS)
Morris, C. M.; Valdés Aguilar, R.; Ghosh, A.; Koohpayeh, S. M.; Krizan, J.; Cava, R. J.; Tchernyshyov, O.; McQueen, T. M.; Armitage, N. P.
2014-04-01
Kink bound states in the one-dimensional ferromagnetic Ising chain compound CoNb2O6 have been studied using high-resolution time-domain terahertz spectroscopy in zero applied magnetic field. When magnetic order develops at low temperature, nine bound states of kinks become visible. Their energies can be modeled exceedingly well by the Airy function solutions to a 1D Schrödinger equation with a linear confining potential. This sequence of bound states terminates at a threshold energy near 2 times the energy of the lowest bound state. Above this energy scale we observe a broad feature consistent with the onset of the two particle continuum. At energies just below this threshold we observe a prominent excitation that we interpret as a novel bound state of bound states—two pairs of kinks on neighboring chains.
Elastic interactions between two-dimensional geometric defects
NASA Astrophysics Data System (ADS)
Moshe, Michael; Sharon, Eran; Kupferman, Raz
2015-12-01
In this paper, we introduce a methodology applicable to a wide range of localized two-dimensional sources of stress. This methodology is based on a geometric formulation of elasticity. Localized sources of stress are viewed as singular defects—point charges of the curvature associated with a reference metric. The stress field in the presence of defects can be solved using a scalar stress function that generalizes the classical Airy stress function to the case of materials with nontrivial geometry. This approach allows the calculation of interaction energies between various types of defects. We apply our methodology to two physical systems: shear-induced failure of amorphous materials and the mechanical interaction between contracting cells.
Experimental observation of sub-Rayleigh quantum imaging with a two-photon entangled source
Xu, De-Qin; Song, Xin-Bing; Li, Hong-Guo; Zhang, De-Jian; Wang, Hai-Bo; Xiong, Jun Wang, Kaige
2015-04-27
It has been theoretically predicted that N-photon quantum imaging can realize either an N-fold resolution improvement (Heisenberg-like scaling) or a √(N)-fold resolution improvement (standard quantum limit) beyond the Rayleigh diffraction bound, over classical imaging. Here, we report the experimental study on spatial sub-Rayleigh quantum imaging using a two-photon entangled source. Two experimental schemes are proposed and performed. In a Fraunhofer diffraction scheme with a lens, two-photon Airy disk pattern is observed with subwavelength diffraction property. In a lens imaging apparatus, however, two-photon sub-Rayleigh imaging for an object is realized with super-resolution property. The experimental results agree with the theoretical prediction in the two-photon quantum imaging regime.
Nondiffracting accelerating wave packets of Maxwell's equations.
Kaminer, Ido; Bekenstein, Rivka; Nemirovsky, Jonathan; Segev, Mordechai
2012-04-20
We present the nondiffracting spatially accelerating solutions of the Maxwell equations. Such beams accelerate in a circular trajectory, thus generalizing the concept of Airy beams to the full domain of the wave equation. For both TE and TM polarizations, the beams exhibit shape-preserving bending which can have subwavelength features, and the Poynting vector of the main lobe displays a turn of more than 90°. We show that these accelerating beams are self-healing, analyze their properties, and find the new class of accelerating breathers: self-bending beams of periodically oscillating shapes. Finally, we emphasize that in their scalar form, these beams are the exact solutions for nondispersive accelerating wave packets of the most common wave equation describing time-harmonic waves. As such, this work has profound implications to many linear wave systems in nature, ranging from acoustic and elastic waves to surface waves in fluids and membranes. PMID:22680719
Elastic interactions between two-dimensional geometric defects.
Moshe, Michael; Sharon, Eran; Kupferman, Raz
2015-12-01
In this paper, we introduce a methodology applicable to a wide range of localized two-dimensional sources of stress. This methodology is based on a geometric formulation of elasticity. Localized sources of stress are viewed as singular defects-point charges of the curvature associated with a reference metric. The stress field in the presence of defects can be solved using a scalar stress function that generalizes the classical Airy stress function to the case of materials with nontrivial geometry. This approach allows the calculation of interaction energies between various types of defects. We apply our methodology to two physical systems: shear-induced failure of amorphous materials and the mechanical interaction between contracting cells. PMID:26764699
NASA Astrophysics Data System (ADS)
Winkler, Thomas; Sarpe, Cristian; Jelzow, Nikolai; Lasse H., Lillevang; Götte, Nadine; Zielinski, Bastian; Balling, Peter; Senftleben, Arne; Baumert, Thomas
2016-06-01
In this work, laser excitation of water under ambient conditions is investigated by radially resolved common-path spectral interferometry. Water, as a sample system for dielectric materials, is excited by ultrashort bandwidth-limited and temporally asymmetric shaped femtosecond laser pulses, where the latter start with an intense main pulse followed by a decaying pulse sequence, i.e. a temporal Airy pulse. Spectral interference in an imaging geometry allows measurements of the transient optical properties integrated along the propagation through the sample but radially resolved with respect to the transverse beam profile. Since the optical properties reflect the dynamics of the free-electron plasma, such measurements reveal the spatial characteristics of the laser excitation. We conclude that temporally asymmetric shaped laser pulses are a promising tool for high-precision laser material processing, as they reduce the transverse area of excitation, but increase the excitation inside the material along the beam propagation.
Zhou, Jianqin; Shen, Jun; Neill, W Stuart
2016-07-01
A method of frequency analysis for the measurement of the temperature coefficient of refractive index (dn/dT) using a Fabry-Perot interferometer was developed and tested against ethanol and water. The temperature-dependent interferometric signal described by Airy's formula was analyzed in both the temperature and frequency domains. By fast Fourier transform, a low-pass filter was designed and employed to eliminate the noise superimposed on the signal. dn/dT was determined accurately from the noise-removed signal by peak analysis. Furthermore, the signal frequency parameters may be utilized for the material thermophysical property characterization. This method lays the foundation for an online dn/dT instrument for monitoring chemical processes. PMID:27475545
A deterministic approach toward isostatic gravity residuals: A case study from South America
Chapin, D.A.
1994-12-31
Isostatic gravity residuals are based upon geologic models, therefore they provide a reasonable basis of comparison over large areas for reconnaissance studies. To help define the best isostatic model for South America, a new deterministic methodology overcomes the deficiencies of other empirically-based methods. The basis for the model was the Airy-Heiskanen (1958) isostatic model, which assumes that surface topography is supported by crustal thickening. The three key parameters -- (a) the crustal thickness at sea-level, (b) the surface reduction density, and (c) the density contrast between the crust and the mantle -- were determined directly from the elevation, free-air gravity, and Bouguer gravity datasets. The results of this work were not only an isostatic residual map, but methodology which cross-checks the data for quality control purposes. The final isostatic residual map can be used in confidence for basin evaluation throughout the continent of South America.
Świrniak, Grzegorz; Mroczka, Janusz
2016-04-01
When a plane electromagnetic wave is scattered by an optically transparent object, whose size is much larger than the wavelength, a series of bright and dark fringes forms the primary rainbow, which is one of the most splendid phenomena in nature. In this work, an optical technique is discussed for simultaneous measurement of the diameter and refractive index of an axisymmetric and dielectric fiber by studying some rainbow features. This noncontact optical technique uses a beam of light exhibiting low temporal coherence, which enabled us to reduce the detrimental sensitivity of the rainbow features to variations of the fiber properties, thus allowing for high-precision estimates. Approximate mathematical formulas for the diameter and refractive index measurements were derived from the lowest-order complex angular momentum correction to Airy theory of rainbow. Furthermore, sensitivity of the measurement data to small deformation of the fiber's cross section into an ellipse was discussed. Preliminary empirical results provide a qualitative verification. PMID:27140778
Generalized Jinc functions and their application to focusing and diffraction of circular apertures
NASA Astrophysics Data System (ADS)
Cao, Qing
2003-04-01
A family of generalized Jinc functions is defined and analyzed. The zero-order one is just the traditional Jinc function. In terms of these functions, series-form expressions are presented for the Fresnel diffraction of a circular aperture illuminated by converging spherical waves or plane waves. The leading term is nothing but the Airy formula for the Fraunhofer diffraction of circular apertures, and those high-order terms are directly related to those high-order Jinc functions. The truncation error of the retained terms is also analytically investigated. We show that, for the illumination of a converging spherical wave, the first 19 terms are sufficient for describing the three-dimensional field distribution in the whole focal region.
Localization in supergravity and quantum AdS 4 /CFT3 holography
NASA Astrophysics Data System (ADS)
Dabholkar, Atish; Drukker, Nadav; Gomes, João
2014-10-01
We compute the quantum gravity partition function of M-theory on AdS 4 × X 7 by using localization techniques in four-dimensional gauged supergravity obtained by a consistent truncation on the Sasaki-Einstein manifold X 7. The supergravity path integral reduces to a finite dimensional integral over two collective coordinates that parametrize the localizing instanton solutions. The renormalized action of the off-shell instanton solutions depends linearly and holomorphically on the "square root" prepotential evaluated at the center of AdS 4. The partition function resembles the Laplace transform of the wave function of a topological string and with an assumption about the measure for the localization integral yields an Airy function in precise agreement with the computation from the boundary ABJM theory on a 3-sphere. Our bulk quantum gravity computation is nonperturbatively exact in four-dimensional Planck length but ignores corrections due to brane-instantons.
Spheroidal droplet measurements based on generalized rainbow patterns
NASA Astrophysics Data System (ADS)
Yu, Haitao; Xu, Feng; Tropea, Cameron
2013-09-01
The character of the rainbow from a droplet is investigated experimentally and theoretically. In the experiment, light scattering from spheroidal droplets in the vicinity of the primary rainbow region has been observed to contain a variety of characteristic interference patterns which are a generalization of the rainbow from a sphere. These patterns start from being a fold rainbow, change to transverse cusp caustics and then to hyperbolic umbilic catastrophe as the aspect ratio of the droplet increases. A comparison of the observed rainbow patterns in the horizontal equatorial plane with those of Airy theory reveals that these patterns can be used for characterizing droplet, in particular for determining the refractive index and the diameter of the droplet in the equatorial plane. The absolute error of the refractive index is smaller than 1.5×10-4. The absolute relative error of the equatorial diameter is less than 5%.