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1

Wave-wave interactions in solar type III radio bursts  

SciTech Connect (OSTI)

The high time resolution observations from the STEREO/WAVES experiment show that in type III radio bursts, the Langmuir waves often occur as localized magnetic field aligned coherent wave packets with durations of a few ms and with peak intensities well exceeding the strong turbulence thresholds. Some of these wave packets show spectral signatures of beam-resonant Langmuir waves, down- and up-shifted sidebands, and ion sound waves, with frequencies, wave numbers, and tricoherences satisfying the resonance conditions of the oscillating two stream instability (four wave interaction). The spectra of a few of these wave packets also contain peaks at f{sub pe}, 2f{sub pe} and 3 f{sub pe} (f{sub pe} is the electron plasma frequency), with frequencies, wave numbers and bicoherences (computed using the wavelet based bispectral analysis techniques) satisfying the resonance conditions of three wave interactions: (1) excitation of second harmonic electromagnetic waves as a result of coalescence of two oppositely propagating Langmuir waves, and (2) excitation of third harmonic electromagnetic waves as a result of coalescence of Langmuir waves with second harmonic electromagnetic waves. The implication of these findings is that the strong turbulence processes play major roles in beam stabilization as well as conversion of Langmuir waves into escaping radiation in type III radio bursts.

Thejappa, G. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); MacDowall, R. J. [NASA/Goddard Space Flight Center, Greenbelt MD 20771 (United States)

2014-02-11T23:59:59.000Z

2

A PLL Design Based on a Standing Wave Resonant Oscillator  

E-Print Network [OSTI]

In this thesis, we present a new continuously variable high frequency standing wave oscillator and demonstrate its use in generating the phase locked clock signal of a digital IC. The ring based standing wave resonant oscillator is implemented...

Karkala, Vinay

2011-10-21T23:59:59.000Z

3

Nonreciprocal wave scattering on nonlinear string-coupled oscillators  

E-Print Network [OSTI]

We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: the same wave is transmitted differently in two directions. Periodic regimes of scattering are analysed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaotic scattering. Moreover, a regime of a "chaotic diode", where transmission is periodic in one direction and chaotic in the opposite one, is reported.

Stefano Lepri; Arkady Pikovsky

2014-10-29T23:59:59.000Z

4

Interactions Between Membrane Conductances Underlying Thalamocortical Slow-Wave Oscillations  

E-Print Network [OSTI]

or oscillations can be explained by interactions between calcium- and voltage-dependent channels. At the networkInteractions Between Membrane Conductances Underlying Thalamocortical Slow-Wave Oscillations A: Oscillations and Bursts Emerging From the Interplay of Intrinsic Conductances in Single Neurons 1404 A

Destexhe, Alain

5

Regenerative oscillation and four-wave mixing in graphene optoelectronics  

E-Print Network [OSTI]

Regenerative oscillation and four-wave mixing in graphene optoelectronics T. Gu1 *, N. Petrone2 , J consecutive first observations in graphene­ silicon hybrid optoelectronic devices--ultralow-power resonant optoelectronics and all-optical signal processing. S ubwavelength nanostructures in monolithic material platforms

Hone, James

6

Josephson oscillations of charge density waves  

SciTech Connect (OSTI)

The formation of charge density waves in solids was originally proposed as a possible mechanism for superconductivity by Froehlich. Although the experimentally discovered materials with charge density waves (CDW)s are found to have finite resistivity as a result of impurity pinning, they nevertheless reveal many interesting features including motion which is analogous to a resistively shunted Josephson junction of superconductors. The noise spectrum of CDW systems is reviewed with particular emphasis on interactions with normal as well as magnetic impurities. Future prospects for observing an amplitude variation of the noise signals induced by a magnetic field are proposed.

Ruvalds, J.; Tua, P.F.

1985-01-01T23:59:59.000Z

7

Wave kernels for the Dirac, Euler operators and the harmonic oscillator  

SciTech Connect (OSTI)

Explicit solutions for the wave equations associated to the Dirac, Euler operators and the harmonic oscillator are given.

Mohameden, Ahmedou Yahya Ould, E-mail: ahmeddou2011@yahoo.fr; Moustapha, Mohamed Vall Ould, E-mail: khames@univ-nkc.mr [Université des Sciences, de Technologie et de la Medécine (USTM) Faculté des Sciences et Techniques. Département de Mathématiques et Informatique, Unité de Recherche: Analyse, EDP et Modélisation: (AEDPM) B.P: 5026, Nouakchott-Mauritanie (United States)

2014-03-15T23:59:59.000Z

8

On the Production of Dissipation by Interaction of Forced Oscillating Waves  

E-Print Network [OSTI]

and parabolic type, oscillations, BKW Calculus, sta- bility. 1 Introduction In Section 1, we introduce

Paris-Sud XI, Université de

9

Resonant energy conversion of 3-minute intensity oscillations into Alfven waves in the solar atmosphere  

E-Print Network [OSTI]

Nonlinear coupling between 3-minute oscillations and Alfven waves in the solar lower atmosphere is studied. 3-minute oscillations are considered as acoustic waves trapped in a chromospheric cavity and oscillating along transversally inhomogeneous vertical magnetic field. It is shown that under the action of the oscillations the temporal dynamics of Alfven waves is governed by Mathieu equation. Consequently, the harmonics of Alfven waves with twice period and wavelength of 3-minute oscillations grow exponentially in time near the layer where the sound and Alfven speeds equal. Thus the 3-minute oscillations are resonantly absorbed by pure Alfven waves near this resonant layer. The resonant Alfven waves may penetrate into the solar corona taking energy from the chromosphere. Therefore the layer c_s=v_A may play a role of energy channel for otherwise trapped acoustic oscillations.

D. Kuridze; T. V. Zaqarashvili

2007-03-19T23:59:59.000Z

10

A powerful reflector in relativistic backward wave oscillator  

SciTech Connect (OSTI)

An improved TM{sub 021} resonant reflector is put forward. Similarly with most of the slow wave structures used in relativistic backward wave oscillator, the section plane of the proposed reflector is designed to be trapezoidal. Compared with the rectangular TM{sub 021} resonant reflector, such a structure can depress RF breakdown more effectively by weakening the localized field convergence and realizing good electrostatic insulation. As shown in the high power microwave (HPM) generation experiments, with almost the same output power obtained by the previous structure, the improved structure can increase the pulse width from 25?ns to over 27?ns and no obvious surface damage is observed even if the generated HPM pulses exceed 1000 shots.

Cao, Yibing, E-mail: caoyibing@nint.ac.cn; Sun, Jun; Teng, Yan; Zhang, Yuchuan; Zhang, Lijun; Shi, Yanchao; Ye, Hu; Chen, Changhua [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China)

2014-09-15T23:59:59.000Z

11

Asymmetric modes decomposition in an overmoded relativistic backward wave oscillator  

SciTech Connect (OSTI)

Most of the investigated overmoded relativistic backward wave oscillators (RBWOs) are azimuthally symmetric; thus, they are designed through two dimensional (2-D) particle-in-cell (PIC) simulations. However, 2-D PIC simulations cannot reveal the effect of asymmetric modes on beam-wave interaction. In order to investigate whether asymmetric mode competition needs to be considered in the design of overmoded RBWOs, a numerical method of determining the composition of both symmetric and asymmetric modes in three dimensional (3-D) PIC simulations is introduced in this paper. The 2-D and 3-D PIC simulation results of an X-band overmoded RBWO are analyzed. Our analysis indicates that the 2-D and 3-D PIC simulation results of our device are quite different due to asymmetric mode competition. In fact, asymmetric surface waves, especially EH{sub 11} mode, can lead to serious mode competition when electron beam propagates near the surface of slow wave structures (SWSs). Therefore, additional method of suppressing asymmetric mode competition, such as adjusting the reflections at both ends of SWSs to decrease the Q-factor of asymmetric modes, needs to be utilized in the design of overmoded RBWOs. Besides, 3-D PIC simulation and modes decomposition are essential for designing overmoded RBWOs.

Zhang, Dian; Zhang, Jun, E-mail: zhangjun@nudt.edu.cn; Zhong, Huihuang; Jin, Zhenxing; Ju, Jinchuan [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2014-09-15T23:59:59.000Z

12

Reference Model 6 (RM6): Oscillating Wave Energy Converter.  

SciTech Connect (OSTI)

This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter reference model design in a complementary manner to Reference Models 1-4 contained in the above report. In this report, a conceptual design for an Oscillating Water Column Wave Energy Converter (WEC) device appropriate for the modeled reference resource site was identified, and a detailed backward bent duct buoy (BBDB) device design was developed using a combination of numerical modeling tools and scaled physical models. Our team used the methodology in SAND2013-9040 for the economic analysis that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays, up to 100 devices. The methodology was applied to identify key cost drivers and to estimate levelized cost of energy (LCOE) for this RM6 Oscillating Water Column device in dollars per kilowatt-hour (%24/kWh). Although many costs were difficult to estimate at this time due to the lack of operational experience, the main contribution of this work was to disseminate a detailed set of methodologies and models that allow for an initial cost analysis of this emerging technology. This project is sponsored by the U.S. Department of Energy's (DOE) Wind and Water Power Technologies Program Office (WWPTO), within the Office of Energy Efficiency & Renewable Energy (EERE). Sandia National Laboratories, the lead in this effort, collaborated with partners from National Laboratories, industry, and universities to design and test this reference model.

Bull, Diana L; Smith, Chris; Jenne, Dale Scott; Jacob, Paul; Copping, Andrea; Willits, Steve; Fontaine, Arnold; Brefort, Dorian; Gordon, Margaret Ellen; Copeland, Robert; Jepsen, Richard A.

2014-10-01T23:59:59.000Z

13

Effect of non-uniform slow wave structure in a relativistic backward wave oscillator with a resonant reflector  

SciTech Connect (OSTI)

This paper provides a fresh insight into the effect of non-uniform slow wave structure (SWS) used in a relativistic backward wave oscillator (RBWO) with a resonant reflector. Compared with the uniform SWS, the reflection coefficient of the non-uniform SWS is higher, leading to a lower modulating electric field in the resonant reflector and a larger distance to maximize the modulation current. Moreover, for both types of RBWOs, stronger standing-wave field takes place at the rear part of the SWS. In addition, besides Cerenkov effects, the energy conversion process in the RBWO strongly depends on transit time effects. Thus, the matching condition between the distributions of harmonic current and standing wave field provides a profound influence on the beam-wave interaction. In the non-uniform RBWO, the region with a stronger standing wave field corresponds to a higher fundamental harmonic current distribution. Particle-in-cell simulations show that with a diode voltage of 1.02 MV and beam current of 13.2 kA, a microwave power of 4 GW has been obtained, compared to that of 3 GW in the uniform RBWO.

Chen, Changhua; Xiao, Renzhen; Sun, Jun; Song, Zhimin; Huo, Shaofei; Bai, Xianchen; Shi, Yanchao; Liu, Guozhi [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)] [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

2013-11-15T23:59:59.000Z

14

Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter  

SciTech Connect (OSTI)

This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter (OSWEC) reference model design in a complementary manner to Reference Models 1-4 contained in the above report. A conceptual design for a taut moored oscillating surge wave energy converter was developed. The design had an annual electrical power of 108 kilowatts (kW), rated power of 360 kW, and intended deployment at water depths between 50 m and 100 m. The study includes structural analysis, power output estimation, a hydraulic power conversion chain system, and mooring designs. The results were used to estimate device capital cost and annual operation and maintenance costs. The device performance and costs were used for the economic analysis, following the methodology presented in SAND2013-9040 that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays up to 100 devices. The levelized cost of energy estimated for the Reference Model 5 OSWEC, presented in this report, was for a single device and arrays of 10, 50, and 100 units, and it enabled the economic analysis to account for cost reductions associated with economies of scale. The baseline commercial levelized cost of energy estimate for the Reference Model 5 device in an array comprised of 10 units is $1.44/kilowatt-hour (kWh), and the value drops to approximately $0.69/kWh for an array of 100 units.

Yu, Y. H.; Jenne, D. S.; Thresher, R.; Copping, A.; Geerlofs, S.; Hanna, L. A.

2015-01-01T23:59:59.000Z

15

Multiscale modeling of oscillations and spiral waves in Dictyostelium populations  

E-Print Network [OSTI]

Unicellular organisms exhibit elaborate collective behaviors in response to environmental cues. These behaviors are controlled by complex biochemical networks within individual cells and coordinated through cell-to-cell communication. Describing these behaviors requires new mathematical models that can bridge scales -- from biochemical networks within individual cells to spatially structured cellular populations. Here, we present a family of multiscale models for the emergence of spiral waves in the social amoeba Dictyostelium discoideum. Our models exploit new experimental advances that allow for the direct measurement and manipulation of the small signaling molecule cAMP used by Dictyostelium cells to coordinate behavior in cellular populations. Inspired by recent experiments, we model the Dictyostelium signaling network as an excitable system coupled to various pre-processing modules. We use this family of models to study spatially unstructured populations by constructing phase diagrams that relate the properties of population-level oscillations to parameters in the underlying biochemical network. We then extend our models to include spatial structure and show how they naturally give rise to spiral waves. Our models exhibit a wide range of novel phenomena including a density dependent frequency change, bistability, and dynamic death due to slow cAMP dynamics. Our modeling approach provides a powerful tool for bridging scales in modeling of Dictyostelium populations.

Javad Noorbakhsh; David Schwab; Allyson Sgro; Thomas Gregor; Pankaj Mehta

2014-09-12T23:59:59.000Z

16

SiGe BiCMOS Topologies for Low-Voltage Millimeter-Wave Voltage Controlled Oscillators and Frequency Dividers  

E-Print Network [OSTI]

SiGe BiCMOS Topologies for Low-Voltage Millimeter-Wave Voltage Controlled Oscillators and Frequency-mail: tod@eecg.toronto.edu Abstract -- BiCMOS topologies for mm-wave voltage- controlled oscillators operation for mm-wave applications. II. BICMOS VOLTAGE-CONTROLLED OSCILLATOR The Colpitts topology

Voinigescu, Sorin Petre

17

PERSISTENT DOPPLER SHIFT OSCILLATIONS OBSERVED WITH HINODE/EIS IN THE SOLAR CORONA: SPECTROSCOPIC SIGNATURES OF ALFVENIC WAVES AND RECURRING UPFLOWS  

SciTech Connect (OSTI)

Using data obtained by the EUV Imaging Spectrometer on board Hinode, we have performed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of oscillations from February to April in 2007. One type is found at loop footpoint regions, with a dominant period around 10 minutes. They are characterized by coherent behavior of all line parameters (line intensity, Doppler shift, line width, and profile asymmetry), and apparent blueshift and blueward asymmetry throughout almost the entire duration. Such oscillations are likely to be signatures of quasi-periodic upflows (small-scale jets, or coronal counterpart of type-II spicules), which may play an important role in the supply of mass and energy to the hot corona. The other type of oscillation is usually associated with the upper part of loops. They are most clearly seen in the Doppler shift of coronal lines with formation temperatures between one and two million degrees. The global wavelets of these oscillations usually peak sharply around a period in the range of three to six minutes. No obvious profile asymmetry is found and the variation of the line width is typically very small. The intensity variation is often less than 2%. These oscillations are more likely to be signatures of kink/Alfven waves rather than flows. In a few cases, there seems to be a {pi}/2 phase shift between the intensity and Doppler shift oscillations, which may suggest the presence of slow-mode standing waves according to wave theories. However, we demonstrate that such a phase shift could also be produced by loops moving into and out of a spatial pixel as a result of Alfvenic oscillations. In this scenario, the intensity oscillations associated with Alfvenic waves are caused by loop displacement rather than density change. These coronal waves may be used to investigate properties of the coronal plasma and magnetic field.

Tian Hui; McIntosh, Scott W. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States); Wang, Tongjiang; Ofman, Leon [Department of Physics, Catholic University of America, Washington, DC 20064 (United States); De Pontieu, Bart [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover St., Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States); Innes, Davina E.; Peter, Hardi, E-mail: htian@ucar.edu [Max Planck Institute for Solar System Research, 37191 Katlenburg-Lindau (Germany)

2012-11-10T23:59:59.000Z

18

Noncommutative quantum mechanics of a harmonic oscillator under linearized gravitational waves  

E-Print Network [OSTI]

We consider the quantum dynamics of a harmonic oscillator in noncommutative space under the influence of linearized gravitational waves (GW) in the long wave-length and low-velocity limit. Following the prescription in \\cite{ncgw1} we quantize the system. The Hamiltonian of the system is solved by using standard algebraic iterative methods. The solution shows signatures of the coordinate noncommutativity via alterations in the oscillation frequency of the harmonic oscillator system from its commutative counterpart. Moreover, it is found that the response of the harmonic oscillator to periodic GW, when their frequencies match, will oscillate with a time scale imposed by the NC parameter. We expect this noncommutative signature to show up as some noise source in the GW detection experiments since the recent phenomenological upper-bounds set on spatial noncommutative parameter implies a length-scale comparable to the length-variations due to the passage of gravitational waves, detectable in the present day GW detectors.

Anirban Saha; Sunandan Gangopadhyay; Swarup Saha

2011-06-09T23:59:59.000Z

19

Wave Energy Extraction from an Oscillating Water Column in a Truncated Circular Cylinder  

E-Print Network [OSTI]

Oscillating Water Column (OWC) device is a relatively practical and convenient way that converts wave energy to a utilizable form, which is usually electricity. The OWC is kept inside a fixed truncated vertical cylinder, which is a hollow structure...

Wang, Hao

2013-07-19T23:59:59.000Z

20

of SOHO `Waves, Oscillations SmallScale Transient in Solar Atmosphere  

E-Print Network [OSTI]

of SOHO `Waves, Oscillations Small­Scale Transient in Solar Atmosphere: A Joint from SOHO TRACE identified from SUMER Atlas Curdt (2001). studied shifts widths 703.87 � 8 � 4 coronal ## 706.02 �(# 6

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Optical disk resonators with micro-wave free spectral range for optoelectronic oscillator  

E-Print Network [OSTI]

Optical disk resonators with micro-wave free spectral range for optoelectronic oscillator Herv to the resonator relaxation time = Q/ [2]. The optoelectronic delayed feed- back loop can thus oscillate at all. frequency selective resonator (e.g with a high Q factor). The detailed architecture is an optoelectronic

Paris-Sud XI, Université de

22

Stochastic excitation and damping of solar-type oscillations  

E-Print Network [OSTI]

A review on acoustic mode damping and excitation in solar-type stars is presented. Current models for linear damping rates are discussed in the light of recent low-degree solar linewidth measurements with emphasis on the frequency-dependence of damping rates of low-order modes. Recent developments in stochastic excitation models are reviewed and tested against the latest high-quality data of solar-like oscillations, such as from alpha Cen A, and against results obtained from hydrodynamical simulations.

G. Houdek

2006-12-01T23:59:59.000Z

23

Modelling of a self-sustained density wave oscillation and its neutronic response in a three-dimensional heterogeneous system  

E-Print Network [OSTI]

can bring local oscillations of the reactor power. Density wave oscillations in heated channels haveModelling of a self-sustained density wave oscillation and its neutronic response in a three, Department of Applied Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden a r t i c l e

Demazière, Christophe

24

PHYSICS CURRICULUM PH 101: Introductory Physics I -Mechanics, oscillations and waves (2:1)  

E-Print Network [OSTI]

PHYSICS CURRICULUM Semester 1 PH 101: Introductory Physics I - Mechanics, oscillations and waves (2:1) Physical quantities, measurements and vectors, Kinematics: Description of Motion, The Laws of Motion mechanics, Fluid mechanics, Waves-II, Nonlinear dynamics Semester 2 PH 102: Introductory Physics II

Srinivasan, N.

25

A new type of surface waves in a fully degenerate quantum plasma  

E-Print Network [OSTI]

We study the response of a semi-bounded one-component fully degenerate electron plasma to an initial perturbation in the electrostatic limit. We show that the part of the electric potential corresponding to surface waves in such plasma can be represented, at large times, as the sum of two terms, one term corresponding to "conventional" (Langmuir) surface waves and the other term representing a new type of surface waves resulting from specific analytic properties of degenerate plasma's dielectric response function. These two terms are characterized by different oscillation frequencies (for a given wave number), and, while the "conventional" term's amplitude decays exponentially with time, the new term is characterized by a slower, power-law decay of the oscillation amplitude and is therefore dominant at large times.

Yuriy Tyshetskiy; Roman Kompaneets; Sergey V. Vladimirov

2014-04-06T23:59:59.000Z

26

Vacuum Rabi oscillation of an atom without rotating-wave approximation  

E-Print Network [OSTI]

We have investigated vacuum Rabi oscillation of an atom coupled with single-mode cavity field exactly, and compared the results with that of J-C model. The results show that, there is damping Rabi oscillation for an atom, even in strong coupling regime. For small detuning and weak coupling case, the probability for the atom in excited state oscillates against time with different frequency and amplitude from that of J-C model. It exhibits the counter-rotating wave interaction could significantly effect the dynamic behavior of the atom, even under the condition in which the RWA is considered to be justified. On the other hand, the results also reveal that the counter-rotating wave interaction could obviously modify the decay rate in strong coupling regime. And there is Rabi oscillation for initially unexcited atom, which is contrary to that of J-C model.

Fa-Qiang Wang; Wei-Ci Liu; Rui-Sheng Liang

2008-07-16T23:59:59.000Z

27

A watt-class 1-THz backward-wave oscillator based on sine waveguide  

SciTech Connect (OSTI)

A novel backward wave oscillator was proposed by utilizing a concise sine waveguide slow-wave structure combined with sheet electron beam to operate at terahertz frequency band. First, the design method was described, and the dispersion curve and interaction impedance of the sine waveguide were calculated, then the device oscillation frequency and operating voltage were determined. Next, the circuit transmission losses were learned over the tunable frequency range. Finally, the particle-in-cell simulation method was applied to predict its signal generation performance. The investigation results show that, the backward wave oscillator can produce over 1.9 -W peak power output at the central operating frequency of 1-THz under 27-kV operating voltage and 5-mA beam current. And the interaction efficiency at 1-THz is more than 1.4% with a circuit length of 7.2-mm. It, therefore, will be considered as a promising watt-class terahertz radiation source.

Xu Xiong; Wei Yanyu; Shen Fei; Yin Hairong; Xu Jin; Gong Yubin; Wang Wenxiang

2012-01-15T23:59:59.000Z

28

Shapiro steps and stimulated radiation of electromagnetic waves due to Josephson oscillations in layered superconductors.  

SciTech Connect (OSTI)

Single crystals of layered high-temperature superconductors intrinsically behave as stacks of Josephson junctions. We analyze response of current-biased stack of intrinsic junctions to irradiation by the external electromagnetic (em) wave. In addition to well-known Shapiro steps in the current-voltage characteristics, irradiation promotes stimulated radiation which adds with spontaneous Josephson radiation from the crystal. Such enhancement of radiation from current-biased crystal may be used for amplification of em waves. Irradiation also facilitates synchronization of Josephson oscillations in all intrinsic Josephson junctions of a single crystal as well as oscillations in intrinsic junctions of different crystals.

Bulaevskii, L. N.; Kosehlev, A. E.; Tachiki, M.; Materials Science Division; LANL; Univ. of Tokyo

2008-01-01T23:59:59.000Z

29

Experimental and Numerical Study of Spar Buoy-magnet/spring Oscillators Used as Wave Energy Annette R. Grilli  

E-Print Network [OSTI]

Experimental and Numerical Study of Spar Buoy-magnet/spring Oscillators Used as Wave Energy at least one short-stroke linear generator (SSLG), made of a magnet, suspended to a spring, and oscillating within a coil. This system is aimed at producing low and renewable wave power (up to ¢ £ ¤ ¥ k

Grilli, Stéphan T.

30

Resistance Fluctuations and AharonovBohm-Type Oscillations in Antidot Arrays in the Quantum Hall Regime  

E-Print Network [OSTI]

Resistance Fluctuations and Aharonov­Bohm-Type Oscillations in Antidot Arrays in the Quantum Hall fluctuations (RFs) and the other is the Aharonov­Bohm (AB)-type oscillations. Their dependences on the magnetic field and the gate voltage are quite distinct. While the aperiodic RFs are attributed to the complex

Iye, Yasuhiro

31

Annular wave packets at Dirac points and probability oscillation in graphene  

E-Print Network [OSTI]

Wave packets in graphene whose central wave vector is at Dirac points are investigated by numerical calculations. Starting from an initial Gaussian function, these wave packets form into annular peaks that propagate to all directions like ripple-rings on water surface. At the beginning, electronic probability alternates between the central peak and the ripple-rings and transient oscillation occurs at the center. As time increases, the ripple-rings propagate at the fixed Fermi speed, and their widths remain unchanged. The axial symmetry of the energy dispersion leads to the circular symmetry of the wave packets. The fixed speed and widths, however, are attributed to the linearity of the energy dispersion. Interference between states that respectively belong to two branches of the energy dispersion leads to multiple ripple-rings and the probability-density oscillation. In a magnetic field, annular wave packets become confined and no longer propagate to infinity. If the initial Gaussian width differs greatly from the magnetic length, expanding and shrinking ripple-rings form and disappear alternatively in a limited spread, and the wave packet resumes the Gaussian form frequently. The probability thus oscillates persistently between the central peak and the ripple-rings. If the initial Gaussian width is close to the magnetic length, the wave packet retains the Gaussian form and its height and width oscillate with a period determined by the first Landau energy. The wave-packet evolution is determined jointly by the initial state and the magnetic field, through the electronic structure of graphene in a magnetic field.

Ji Luo; Junqiang Lu; Daniel Valencia

2011-08-12T23:59:59.000Z

32

The mechanism and realization of a band-agile coaxial relativistic backward-wave oscillator  

SciTech Connect (OSTI)

The mechanism and realization of a band-agile coaxial relativistic backward-wave oscillator (RBWO) are presented. The operation frequency tuning can be easily achieved by merely altering the inner-conductor length. The key effects of the inner-conductor length contributing to the mechanical frequency tunability are investigated theoretically and experimentally. There is a specific inner-conductor length where the operation frequency can jump from one mode to another mode, which belongs to a different operation band. In addition, the operation frequency is tunable within each operation band. During simulation, the L-band microwave with a frequency of 1.61 GHz is radiated when the inner-conductor length is 39?cm. Meanwhile, the S-band microwave with a frequency of 2.32 GHz is radiated when the inner-conductor length is 5?cm. The frequency adjustment bandwidths of L-band and S-band are about 8.5% and 2%, respectively. Moreover, the online mechanical tunability process is described in detail. In the initial experiment, the generated microwave frequencies remain approximately 1.59 GHz and 2.35?GHz when the inner-conductor lengths are 39?cm and 5?cm. In brief, this technical route of the band-agile coaxial RBWO is feasible and provides a guide to design other types of band-agile high power microwaves sources.

Ge, Xingjun; Zhang, Jun; Zhong, Huihuang; Qian, Baoliang; Wang, Haitao [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2014-11-03T23:59:59.000Z

33

5-minute Solar Oscillations and Ion Cyclotron Waves in the Solar Wind  

E-Print Network [OSTI]

In the present paper we study impact of the photospheric 5-minute oscillations on the ion cyclotron waves in the solar wind. We proceed from the assumption that the ion cyclotron waves in solar wind are experiencing modulation with a characteristic period of 5 minutes under the influence of Alfven waves driven by photospheric motions. The theory presented in our paper predicts a deep frequency modulation of the ion cyclotron waves. The frequency modulation is expected mainly from variations in orientation of the IMF lines. In turn, the variations in orientation are caused by the Alfven waves, propagating from the Sun. To test the theoretical predictions we have analyzed records of the ultra-low-frequency (ULF) geoelectromagnetic waves in order to find the permanent quasi-monochromatic oscillations of natural origin in the Pc1-2 frequency band (0.1-5 Hz), the carrier frequency of which varies with time in a wide range. As a result we found the so-called "serpentine emission" (SE), which was observed in Antarct...

Guglielmi, Anatol; Dovbnya, Boris

2015-01-01T23:59:59.000Z

34

Damping of Type I X-ray Burst Oscillations by Convection  

E-Print Network [OSTI]

I construct a simple model of the convective burning layer during a type I X-ray burst to investigate the effects convection has on the stability of the layer to nonradial oscillations. A linear perturbation analysis demonstrates that the region is stable to nonradial oscillations when energy transport is convection-dominated, but it is unstable when energy transport is radiation-dominated. Thus, efficient convection always dampens oscillations. These results may explain the nondetection of oscillations during the peak of some X-ray bursts.

Randall L. Cooper

2008-03-26T23:59:59.000Z

35

Super-radiant backward-wave oscillators with enhanced power conversion  

SciTech Connect (OSTI)

We propose a method for a very significant increase of the peak power of a backward-wave electron oscillator operating in the non-stationary regime of the super-radiation of short rf pulses. This method is based on sectioning: a regular self-oscillator section is supported with a section providing amplification of the super-radiant pulse. Profiling of a resonant parameter in the amplifying section is used to avoid the parasitic self-excitation and to increase the efficiency of the electron-wave interaction. In such systems, the conversion factor (the ratio between the rf pulse power and the electron beam power) can achieve a few hundred percent.

Rostov, V. V. [Institute of High Current Electronics, Siberian Branch of Russian Academy of Science, Tomsk (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia, and Lobachevsky State University of Nizhny Novgorod (Russian Federation)

2013-02-15T23:59:59.000Z

36

Nonlinear oscillations and waves in an arbitrary mass ratio cold plasma  

SciTech Connect (OSTI)

It is well known that nonlinear standing oscillations in an arbitrary mass ratio cold plasma always phase mix away. However, there exist nonlinear electron-ion traveling wave solutions, which do not exhibit phase mixing because they have zero ponderomotive force. The existence of these waves has been demonstrated using a perturbation method. Moreover, it is shown that cold plasma BGK waves [Albritton et al., Nucl. Fusion 15, 1199 (1975)] phase mix away if ions are allowed to move and the scaling of phase mixing is found to be different from earlier work [Sengupta et al., Phys. Rev. Lett. 82, 1867 (1999)]. Phase mixing of these waves has been further verified in 1-D particle in cell simulation.

Verma, Prabal Singh [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2011-12-15T23:59:59.000Z

37

Multi-pulse operation of a super-radiant backward-wave oscillator  

SciTech Connect (OSTI)

Theory of a backward-wave electron oscillator operating in the non-stationary regime of super-radiation of short powerful rf pulses is developed. It is shown that there exist multi-frequency regimes of generation of either two-peak or three-peak output signal with different characteristic frequencies in every peak. The use of such regimes allows increasing the duration, the peak power, and the total energy of the output super-radiation rf pulse.

Bandurkin, I. V. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod, 603950 (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod, 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod (Russian Federation)

2014-08-15T23:59:59.000Z

38

Wave Functions and Energy Terms of the SCHRÖdinger Equation with Two-Center Coulomb Plus Harmonic Oscillator Potential  

E-Print Network [OSTI]

Schr\\"odinger equation for two center Coulomb plus harmonic oscillator potential is solved by the method of ethalon equation at large intercenter separations. Asymptotical expansions for energy term and wave function are obtained in the analytical form.

D. Matrasulov

1998-04-17T23:59:59.000Z

39

Prediction of net bedload transport rates obtained in oscillating water tunnels and applicability to real surf zone waves  

E-Print Network [OSTI]

Experimental studies of sediment transport rates due to near shore waves are often conducted in oscillating water tunnels (OWTs). In an OWT, the oscillatory motion produced by the piston propagates almost instantaneously ...

Gonzalez-Rodriguez, David

40

The role of linear and voltage-dependent ionic currents in the generation of slow wave oscillations  

E-Print Network [OSTI]

The role of linear and voltage-dependent ionic currents in the generation of slow wave oscillations voltages, re- spectively. Oscillations are created by inward currents driving the cell away from rest voltages and one outward current that repolarizes the cell. Such currents have traditionally been assumed

Bose, Amitabha

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Design and Analysis for a Floating Oscillating Surge Wave Energy Converter: Preprint  

SciTech Connect (OSTI)

This paper presents a recent study on the design and analysis of an oscillating surge wave energy converter. A successful wave energy conversion design requires the balance between the design performance and cost. The cost of energy is often used as the metric to judge the design of the wave energy conversion system. It is often determined based on the device power performance, the cost for manufacturing, deployment, operation and maintenance, as well as the effort to ensure the environmental compliance. The objective of this study is to demonstrate the importance of a cost driven design strategy and how it can affect a WEC design. Three oscillating surge wave energy converter (OSWEC) designs were used as the example. The power generation performance of the design was modeled using a time-domain numerical simulation tool, and the mass properties of the design were determined based on a simple structure analysis. The results of those power performance simulations, the structure analysis and a simple economic assessment were then used to determine the cost-efficiency of selected OSWEC designs. Finally, a discussion on the environmental barrier, integrated design strategy and the key areas that need further investigation is also presented.

Yu, Y. H.; Li, Y.; Hallett, K.; Hotimsky, C.

2014-03-01T23:59:59.000Z

42

APPROXIMATE HARTREE TYPE WAVE FUNCTIONS AND MATRIX ELEMENTS FOR...  

Office of Scientific and Technical Information (OSTI)

APPROXIMATE HARTREE TYPE WAVE FUNCTIONS AND MATRIX ELEMENTS FOR THE K AND L SHELLS OF ATOMS AND IONS Re-direct Destination: Temp Data Fields Meyerott, R.E. Temp Data Storage 3:...

43

Stable coaxial-waveguide gyrotron backward-wave oscillator with distributed losses  

SciTech Connect (OSTI)

This study analyzes the performance of a coaxial-waveguide gyrotron backward-wave oscillator (gyro-BWO) operating at the fundamental harmonic by considering mode competition, which may be attributed to higher-order axial modes and competing transverse modes. In the coaxial waveguide with a short length and uniform cross section, the threshold currents of the higher-order axial modes are substantially higher than the operating current. Additionally, when the beam voltage or the magnetic field is adjusted, the oscillation that neighbors the minimum start-oscillation current of a transverse mode has a positive-k{sub z} field profile, and is excited near the cutoff frequency. As a result, the distributed wall losses at the downstream end of the interaction structure effectively damp the positive-k{sub z} field, and raise significantly the minimum start-oscillation currents of the competing transverse modes. This study also investigates how the parameters, including lossy section length, outer wall resistivity, inner wall resistivity, and ratio of the outer radius to the inner radius, affect the start-oscillation currents of the competing transverse modes in order to obtain stable operation conditions in the frequency tuning range. As is forecasted, when using a 15 A electron beam, the Ka-band coaxial gyro-BWO produces an output power of 137 kW and 3 dB bandwidth of 4.2% by magnetic tuning and an output power of 145 kW and 3dB bandwidth of 2.0% by beam voltage tuning.

Hung, C. L. [Department of Communication Engineering, National Penghu University of Science and Technology, Penghu 880, Taiwan (China)

2010-10-15T23:59:59.000Z

44

Harmonic-oscillator excitations of precise few-body wave functions  

E-Print Network [OSTI]

A method for calculating the occupation probability of the number of harmonic oscillator (HO) quanta is developed for a precise few-body wave function obtained in a correlated Gaussian basis. The probability distributions of two- to four-nucleon wave functions obtained using different nucleon- nucleon (NN) interactions are analyzed to gain insight into the characteristic behavior of the various interactions. Tensor correlations as well as short-range correlations play a crucial role in enhancing the probability of high HO excitations. For the excited states of 4He, the interaction dependence is much less because high HO quanta are mainly responsible for describing the relative motion function between the 3N+N (3H+p and 3He+n) clusters.

W. Horiuchi; Y. Suzuki

2014-08-21T23:59:59.000Z

45

An overmoded relativistic backward wave oscillator with efficient dual-mode operation  

SciTech Connect (OSTI)

A dual-mode operation mechanism in an overmoded relativistic backward wave oscillator is presented. The electron beam interacts with the ?1st space harmonic of TM{sub 01} mode synchronously in the slow wave structure. Then the backward propagating TM{sub 01} mode is converted to the forward propagating TM{sub 02} mode. As the phase velocity of the volume harmonic of TM{sub 02} mode is about twice that of the surface harmonic of TM{sub 01} mode, the TM{sub 02} mode also plays an important role in the high-power microwave generation. Particle-in-cell simulation shows that an efficiency of 48% and a significant improvement of the power capacity have been obtained.

Xiao, Renzhen; Li, Jiawei; Bai, Xianchen; Song, Zhimin; Teng, Yan; Ye, Hu; Li, Xiaoze; Sun, Jun; Chen, Changhua [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Zhang, Xiaowei [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Key Laboratory of Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China)

2014-03-03T23:59:59.000Z

46

Beam-loaded frequency shift study in an over-sized backward wave oscillator  

SciTech Connect (OSTI)

The oversized backward wave oscillator (BWO) can significantly decreases the internal rf electric field in the device. The beam-loaded effect is obvious in such devices and its performance is also significantly affected. Based on the characteristics of the oversized BWO, a self-consistent equation is developed to study its beam-loaded frequency shift together with particle in cell (PIC) simulations. The mechanism whereby the output rf frequency is affected by the beam's parameters and the device's structure is theoretically studied. The frequency's dependence on the drift tube length between the reflector and SWS (slow wave structures) in the device is deduced in the paper and the theoretical results agree with those obtained in PIC simulations.

Li, Zhenghong [Science School, Southwest University of Science and Technology, Mianyang 621021 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621021 (China); Zhou, Zhigang [Science School, Southwest University of Science and Technology, Mianyang 621021 (China); Qiu, Rong [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621021 (China)

2014-10-15T23:59:59.000Z

47

Rational extension and Jacobi-type X{sub m} solutions of a quantum nonlinear oscillator  

SciTech Connect (OSTI)

We construct a rational extension of a recently studied nonlinear quantum oscillator model. Our extended model is shown to retain exact solvability, admitting a discrete spectrum and corresponding closed-form solutions that are expressed through Jacobi-type X{sub m} exceptional orthogonal polynomials.

Schulze-Halberg, Axel [Department of Mathematics and Actuarial Science and Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, Indiana 46408 (United States)] [Department of Mathematics and Actuarial Science and Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, Indiana 46408 (United States); Roy, Barnana [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108 (India)] [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108 (India)

2013-12-15T23:59:59.000Z

48

On The Harmonic Oscillator Group  

E-Print Network [OSTI]

We discuss the maximum kinematical invariance group of the quantum harmonic oscillator from a view point of the Ermakov-type system. A six parameter family of the square integrable oscillator wave functions, which seems cannot be obtained by the standard separation of variables, is presented as an example. The invariance group of generalized driven harmonic oscillator is shown to be isomorphic to the corresponding Schroedinger group of the free particle.

Raquel M. Lopez; Sergei K. Suslov; Jose M. Vega-Guzman

2011-12-04T23:59:59.000Z

49

Oscillating modulation to B-mode polarization from varying propagating speed of primordial gravitational waves  

E-Print Network [OSTI]

In low-energy effective string theory and modified gravity theories, the propagating speed $c_T$ of primordial gravitational waves may deviate from unity. We find that the step-like variation of $c_T$ during slow-roll inflation may result in an oscillating modulation to the B-mode polarization spectrum, which can hardly be imitated by adjusting other cosmological parameters, and the intensity of the modulation is determined by the dynamics of $c_T$. Thus provided that the foreground contribution is under control, high-precision CMB polarization observations will be able to put tight constraint on the variation of $c_T$, and so the corresponding theories.

Cai, Yong; Piao, Yun-Song

2015-01-01T23:59:59.000Z

50

Continuous-wave parametric oscillation in polarisation-maintaining optical fibre  

SciTech Connect (OSTI)

Continuous-wave parametric oscillation in a polarisation-maintaining optical fibre has been achieved for the first time using polarisation phase matching. Up-conversion with a frequency shift of {approx}8.6 THz has been demonstrated experimentally. The single-pass optical power generated at 1017 nm in a 85-m-long Nufern PM980-XP fibre exceeded 40 mW. The conversion efficiency was 3.3%, which is an order of magnitude higher than that reported previously for cw parametric up-conversion in the 1-{mu}m spectral region. We compare theoretical predictions with experimental data and analyse factors that may influence output power saturation with increasing signal and pump powers.

Zlobina, E A; Kablukov, S I; Babin, Sergei A [Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2011-09-30T23:59:59.000Z

51

Harmonic mode competition in a terahertz gyrotron backward-wave oscillator  

SciTech Connect (OSTI)

Electron cyclotron maser interactions at terahertz (THz) frequencies require a high-order-mode structure to reduce the wall loss to a tolerable level. To generate THz radiation, it is also essential to employ cyclotron harmonic resonances to reduce the required magnetic field strength to a value within the capability of the superconducting magnets. However, much weaker harmonic interactions in a high-order-mode structure lead to serious mode competition problems. The current paper addresses harmonic mode competition in the gyrotron backward wave oscillator (gyro-BWO). We begin with a comparative study of the mode formation and oscillation thresholds in the gyro-BWO and gyromonotron. Differences in linear features result in far fewer 'windows' for harmonic operation of the gyro-BWO. Nonlinear consequences of these differences are examined in particle simulations of the multimode competition processes in the gyro-BWO, which shed light on the competition criteria between modes of different as well as the same cyclotron harmonic numbers. The viability of a harmonic gyro-BWO is assessed on the basis of the results obtained.

Kao, S. H.; Chiu, C. C.; Chang, P. C.; Wu, K. L.; Chu, K. R. [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

2012-10-15T23:59:59.000Z

52

ULYSSES DETECTS LONG-SOUGHT WAVE MOTIONS OF THE SUN Periodic oscillations originating from deep within the Sun's  

E-Print Network [OSTI]

ULYSSES DETECTS LONG-SOUGHT WAVE MOTIONS OF THE SUN Periodic oscillations originating from deep within the Sun's interior have been detected for the first time in interplanetary space by the Ulysses mission to the poles of the Sun. The discovery was reported in this week's issue of Nature magazine

Christian, Eric

53

Quasi-optical theory of relativistic surface-wave oscillators with one-dimensional and two-dimensional periodic planar structures  

SciTech Connect (OSTI)

Within the framework of a quasi-optical approach, we develop 2D and 3D self-consistent theory of relativistic surface-wave oscillators. Presenting the radiation field as a sum of two counter-propagating wavebeams coupled on a shallow corrugated surface, we describe formation of an evanescent slow wave. Dispersion characteristics of the evanescent wave following from this method are in good compliance with those found from the direct cst simulations. Considering excitation of the slow wave by a sheet electron beam, we simulate linear and nonlinear stages of interaction, which allows us to determine oscillation threshold conditions, electron efficiency, and output coupling. The transition from the model of surface-wave oscillator operating in the ?-mode regime to the canonical model of relativistic backward wave oscillator is considered. We also described a modified scheme of planar relativistic surface-wave oscillators exploiting two-dimensional periodic gratings. Additional transverse propagating waves emerging on these gratings synchronize the emission from a wide sheet rectilinear electron beam allowing realization of a Cherenkov millimeter-wave oscillators with subgigawatt output power level.

Ginzburg, N. S.; Zaslavsky, V. Yu. [Nizhny Novgorod State University, 23 Gagarin Ave., Nizhny Novgorod 603950 (Russian Federation) [Nizhny Novgorod State University, 23 Gagarin Ave., Nizhny Novgorod 603950 (Russian Federation); Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation); Malkin, A. M.; Sergeev, A. S. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation)] [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanov St., Nizhny Novgorod 603950 (Russian Federation)

2013-11-15T23:59:59.000Z

54

Millimeter-Wave Absorption as a Quality Control Tool for M-Type...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Millimeter-Wave Absorption as a Quality Control Tool for M-Type Hexaferrite Nanopowders. Millimeter-Wave Absorption as a Quality Control Tool for M-Type Hexaferrite Nanopowders....

55

QUASI-PERIODIC FAST-MODE WAVE TRAINS WITHIN A GLOBAL EUV WAVE AND SEQUENTIAL TRANSVERSE OSCILLATIONS DETECTED BY SDO/AIA  

SciTech Connect (OSTI)

We present the first unambiguous detection of quasi-periodic wave trains within the broad pulse of a global EUV wave (so-called EIT wave) occurring on the limb. These wave trains, running ahead of the lateral coronal mass ejection (CME) front of 2-4 times slower, coherently travel to distances {approx}> R{sub Sun }/2 along the solar surface, with initial velocities up to 1400 km s{sup -1} decelerating to {approx}650 km s{sup -1}. The rapid expansion of the CME initiated at an elevated height of 110 Mm produces a strong downward and lateral compression, which may play an important role in driving the primary EUV wave and shaping its front forwardly inclined toward the solar surface. The wave trains have a dominant 2 minute periodicity that matches the X-ray flare pulsations, suggesting a causal connection. The arrival of the leading EUV wave front at increasing distances produces an uninterrupted chain sequence of deflections and/or transverse (likely fast kink mode) oscillations of local structures, including a flux-rope coronal cavity and its embedded filament with delayed onsets consistent with the wave travel time at an elevated (by {approx}50%) velocity within it. This suggests that the EUV wave penetrates through a topological separatrix surface into the cavity, unexpected from CME-caused magnetic reconfiguration. These observations, when taken together, provide compelling evidence of the fast-mode MHD wave nature of the primary (outer) fast component of a global EUV wave, running ahead of the secondary (inner) slow component of CME-caused restructuring.

Liu Wei; Nitta, Nariaki V.; Aschwanden, Markus J.; Schrijver, Carolus J.; Title, Alan M.; Tarbell, Theodore D. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Ofman, Leon, E-mail: weiliu@lmsal.com [Department of Physics, Catholic University of America, Washingtom, DC 20064 (United States)

2012-07-01T23:59:59.000Z

56

On the wave equation in spacetimes of Goedel type  

E-Print Network [OSTI]

We analyze the d'Alembert equation in the Goedel-type spacetimes with spherical and Lobachevsky sections (with sufficiently rapid rotation). By separating the $t$ and $x_3$ dependence we reduce the problem to a group-theoretical one. In the spherical case solutions have discrete frequencies, and involve spin-weighted spherical harmonics. In the Lobachevsky case we give simple formulas for obtaining all the solutions belonging to the $D^\\pm_\\la$ sectors of the irreducible unitary representations of the reduced Lorentz group. The wave equation enforces restrictions on $\\la$ and the allowed (here: continuous) spectrum of frequencies.

P. Marecki

2012-01-24T23:59:59.000Z

57

Inhibitory coupling specifically generates emergent gamma oscillations in diverse cell types  

E-Print Network [OSTI]

phase-locked action potentials during gamma oscillations in entorhinal cortex slices (11). However­3). Isolated networks of FS cells generate emergent gamma oscillations in response to tonic excitation at particular phases of gamma oscillations and or intrinsically oscillate at gamma frequencies and may

Huguenard, John R.

58

Computation of generalized and exact dispersion relations for longitudinal plasma waves in nonextensive statistics and the effects of the nonextensivity on the oscillation modes and damps  

SciTech Connect (OSTI)

We have derived generalized dispersion relations for longitudinal waves in collisionless thermal plasma using linear Vlasov-Poisson kinetic model and nonextensive distributions for electrons. The Maxwellian limit of the dispersion relations, where the q-nonextensive parameter tends to one, is calculated. The generalized dispersion relations are reduced to polynomials for some specific values of q. The well-known modes of oscillations such as the Langmuir and electron acoustic waves have been obtained by solving the dispersion relations. Some new modes of oscillation are also found. Finally, the dependence of the oscillation modes and damps on q is discussed.

Esfandyari-Kalejahi, A.; Ebrahimi, V. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 53714-161 Tabriz (Iran, Islamic Republic of)] [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 53714-161 Tabriz (Iran, Islamic Republic of)

2014-03-15T23:59:59.000Z

59

Wavelength-doubling optical parametric oscillator  

DOE Patents [OSTI]

A wavelength-doubling optical parametric oscillator (OPO) comprising a type II nonlinear optical medium for generating a pair of degenerate waves at twice a pump wavelength and a plurality of mirrors for rotating the polarization of one wave by 90 degrees to produce a wavelength-doubled beam with an increased output energy by coupling both of the degenerate waves out of the OPO cavity through the same output coupler following polarization rotation of one of the degenerate waves.

Armstrong, Darrell J. (Albuquerque, NM); Smith, Arlee V. (Albuquerque, NM)

2007-07-24T23:59:59.000Z

60

Negative spectrum in Harmonic oscillator under simultaneous Non-hermitian transformation of co-ordinate and momentum with Real wave function  

E-Print Network [OSTI]

We notice that PT symmetric non-Hermitian one dimensional simple Harmonic Oscillator under simultaneous transformation of co-ordinate and momentum with proper selection of wave function can also reflect real negative energy eigen spectra provided the associated wave function is well behaved, square integrable and normalised to unity. PACS: 03.65Db, 11.30.Pb, 11.30.Er, 03.65-w Key words: P T symmetry, Non-Hermitian Harmonic oscillator, Negative energy, wave function, simultaneous transformation, co-ordinate, momentum. Perturbation theory.

Biswanath Rath

2015-02-27T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

A continuous-wave second harmonic gyrotron oscillator at 460 GHz  

E-Print Network [OSTI]

We report the short pulse and CW operation of a 460 GHz gyrotron oscillator both at the fundamental (near 230 GHz) and second harmonic (near 460 GHz) of electron cyclotron resonance. During operation in a complete CW regime ...

Hornstein, Melissa K. (Melissa Kristen), 1977-

2005-01-01T23:59:59.000Z

62

Tunability over three frequency bands induced by mode transition in relativistic backward wave oscillator with strong end reflections  

SciTech Connect (OSTI)

This paper presents an efficient approach to realizing the frequency tunability of a relativistic backward wave oscillator (RBWO) over three frequency bands by mode transition without changing the slow wave structure (SWS). It is figured out that the transition of the operation mode in the RBWO can be efficiently achieved by using the strong end reflection of the SWS. This mode transition results in the tunability of the RBWO over three frequency bands at high power and high efficiency without changing the SWS. In numerical simulation, the output frequency of the RBWO can jump over 7.9?GHz in C-band, 9.9?GHz in X-band, and 12.4?GHz in Ku-band with output power exceeding 3.0?GW and conversion efficiency higher than 35% by just reasonably transforming the structures of the front and post resonant reflectors which provide the strong end reflection for the SWS.

Wu, Ping; Deng, Yuqun [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Fan, Juping; Teng, Yan; Shi, Yanchao; Sun, Jun [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

2014-10-15T23:59:59.000Z

63

Wave breaking phenomenon of lower-hybrid oscillations induced by a background inhomogeneous magnetic field  

SciTech Connect (OSTI)

In a fluid description, we study space-time evolution of lower hybrid modes in a cold quasi-neutral homogeneous plasma in presence of a background inhomogeneous magnetic field. Within a linear analysis, a dispersion relation with inhomogeneous magnetic field shows 'phase mixing' of such oscillations. A manifestation of 'phase mixing' is shown in 'mode coupling.' By using Lagrangian variables, an exact solution is presented in parametric form of this nonlinear time dependent problem. It is demonstrated that initially excited lower hybrid modes always break via phase mixing phenomenon in presence of an inhomogeneous magnetic field. Breaking of such oscillations is revealed by the appearance of spikes in the plasma density profile.

Maity, Chandan; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Sengupta, Sudip [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2012-10-15T23:59:59.000Z

64

Model of Thalamocortical Slow-Wave Sleep Oscillations and Transitions to Activated States  

E-Print Network [OSTI]

) in nonanesthetized cats, silent (down) states alternate with active (up) states; the down states are absent during of SWS oscillation activated the persistent sodium current and depolarized the membrane of cortical py- ramidal (PY) cells sufficiently for spike generation. In the model, this triggered the active phase, which

Bazhenov, Maxim

65

Exact solution of D{sub N}-type quantum Calogero model through a mapping to free harmonic oscillators  

SciTech Connect (OSTI)

We solve the eigenvalue problem of the D{sub N}-type of Calogero model by mapping it to a set of decoupled quantum harmonic oscillators through a similarity transformation. In particular, we construct the eigenfunctions of this Calogero model from those of bosonic harmonic oscillators having either all even parity or all odd parity. It turns out that the eigenfunctions of this model are orthogonal with respect to a nontrivial inner product, which can be derived from the quasi-Hermiticity property of the corresponding conserved quantities.

Banerjee, Pratyay; Basu-Mallick, B. [Theory Group, Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064 (India)

2011-05-15T23:59:59.000Z

66

The su(1,1) dynamical algebra from the Schrödinger ladder operators for N-dimensional systems: hydrogen atom, Mie-type potential, harmonic oscillator and pseudo-harmonic oscillator  

E-Print Network [OSTI]

We apply the Schr\\"odinger factorization to construct the ladder operators for hydrogen atom, Mie-type potential, harmonic oscillator and pseudo-harmonic oscillator in arbitrary dimensions. By generalizing these operators we show that the dynamical algebra for these problems is the $su(1,1)$ Lie algebra.

D. Martinez; J. C. Flores-Urbina; R. D. Mota; V. D. Granados

2010-05-21T23:59:59.000Z

67

Harmonic oscillator with time-dependent effective-mass and frequency with a possible application to 'chirped tidal' gravitational waves forces affecting interferometric detectors  

E-Print Network [OSTI]

The general theory of time-dependent frequency and time-dependent mass ('effective mass') is described.The general theory for time-dependent harmonic- oscillator is applied in the present research for studying certain quantum effects in the interferometers for detecting gravitational waves.When an astronomical binary system approaches its point of coalescence the gravitational wave intensity and frequency are increasing and this can lead to strong deviations from the simple description of harmonic-oscillations for the interferometric masses on which the mirrors are placed.It is shown that under such condtions the harmonic-oscillations of these masses can be described by mechanical harmonic-oscillators with time-dependent frequency and effective-mass. In the present theoretical model the effective-mass is decreasing with time describing pumping phenomena in which the oscillator amplitude is increasing with time . The quantization of this system is analyzed by the use of the adiabatic approximation. It is found that the increase of the gravitational wave intensity, within the adiabatic approximation, leads to squeezing phenomena where the quantum noise in one quadrature is increased and in the other quadrature is decreased.

Yacob Ben-Aryeh

2008-07-29T23:59:59.000Z

68

The Contribution of Environmental Siting and Permitting Requirements to the Cost of Energy for Oscillating Water Column Wave Energy Devices  

SciTech Connect (OSTI)

Responsible deployment of marine and hydrokinetic (MHK) devices in estuaries, coastal areas, and major rivers requires that biological resources and ecosystems be protected through siting and permitting (consenting) processes. Scoping appropriate deployment locations, collecting pre-installation (baseline) and post-installation data all add to the cost of developing MHK projects, and hence to the cost of energy. Under the direction of the U.S. Department of Energy, Pacific Northwest National Laboratory scientists have developed logic models that describe studies and processes for environmental siting and permitting. Each study and environmental permitting process has been assigned a cost derived from existing and proposed tidal, wave, and riverine MHK projects, as well as expert opinion of marine environmental research professionals. Cost estimates have been developed at the pilot and commercial scale. The reference model described in this document is an oscillating water column device deployed in Northern California at approximately 50 meters water depth.

Copping, Andrea E.; Geerlofs, Simon H.; Hanna, Luke A.

2013-09-30T23:59:59.000Z

69

Fast Traveling-Wave Reactor of the Channel Type  

E-Print Network [OSTI]

The main aim of this paper is to solve the technological problems of the TWR based on the technical concept described in our priority of invention reference, which makes it impossible, in particular, for the fuel claddings damaging doses of fast neutrons to excess the ~200 dpa limit. Thus the essence of the technical concept is to provide a given neutron flux at the fuel claddings by setting the appropriate speed of the fuel motion relative to the nuclear burning wave. The basic design of the fast uranium-plutonium nuclear traveling-wave reactor with a softened neutron spectrum is developed, which solves the problem of the radiation resistance of the fuel claddings material.

Rusov, Vitaliy D; Vashchenko, Volodymyr N; Chernezhenko, Sergei A; Kakaev, Andrei A; Pantak, Oksana I

2015-01-01T23:59:59.000Z

70

Novel type of chimera spiral waves arising from decoupling of a diffusible component  

SciTech Connect (OSTI)

Spiral waves composed of coherent traveling waves surrounding a core containing stochastically distributed stationary areas are found in numerical simulations of a three-variable reaction-diffusion system with one diffusible species. In the spiral core, diffusion of this component (w) mediates transitions between dynamic states of the subsystem formed by the other two components, whose dynamics is more rapid than that of w. Diffusive coupling between adjacent sites can be “on” or “off” depending on the subsystem state. The incoherent structures in the spiral core are produced by this decoupling of the slow diffusive component from the fast non-diffusing subsystem. The phase diagram reveals that the region of incoherent behavior in chimera spirals grows drastically, leading to modulation and breakup of the spirals, in the transition zones between 1{sup n-1} and 1{sup n} local mixed-mode oscillations.

Tang, Xiaodong; Yang, Tao; Liu, Yang; Zhao, Yuemin; Gao, Qingyu, E-mail: epstein@brandeis.edu, E-mail: gaoqy@cumt.edu.cn [College of Chemical Engineering, China University of Mining and Technology, Xuzhou 221008 (China); Epstein, Irving R., E-mail: epstein@brandeis.edu, E-mail: gaoqy@cumt.edu.cn [Department of Chemistry and Volen Center for Complex Systems, MS 015, Brandeis University, Waltham, Massachusetts 02454-9110 (United States)

2014-07-14T23:59:59.000Z

71

Kinematics of ICMEs/shocks: blast wave reconstruction using type II emissions  

E-Print Network [OSTI]

We present a physical methodology to reconstruct the trajectory of interplanetary shocks using type II radio emission data. This technique calculates the shock trajectory assuming that the disturbance propagates as a blast wave in the interplanetary medium. We applied this Blast Wave Reconstruction (BWR) technique to analyze eight fast Earth-directed ICMEs/shocks associated with type II emissions. The technique deduces a shock trajectory that reproduces the type II frequency drifts, and calculates shock onset speed, shock transit time and shock speed at 1~AU. There were good agreements comparing the BWR results with the type II spectra, with data from coronagraph images, {\\it in situ} measurements, and interplanetary scintillation (IPS) observations. Perturbations on the type II data affect the accuracy of the BWR technique. This methodology could be applied to track interplanetary shocks causing TII emissions in real-time, to predict the shock arrival time and shock speed at 1~AU.

Corona-Romero, P; Aguilar-Rodriguez, E; de-la-Luz, V; Mejia-Ambriz, J C

2015-01-01T23:59:59.000Z

72

Persistent Doppler shift oscillations observed with HINODE/EIS in the solar corona: spectroscopic signatures of Alfvenic waves and recurring upflows  

E-Print Network [OSTI]

Using data obtained by the EUV Imaging Spectrometer (EIS) onboard Hinode, we have per- formed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of oscillations from February to April in 2007. One type is found at loop footpoint regions, with a dominant period around 10 minutes. They are characterized by coherent behavior of all line parameters (line intensity, Doppler shift, line width and profile asymmetry), apparent blue shift and blueward asymmetry throughout almost the en- tire duration. Such oscillations are likely to be signatures of quasi-periodic upflows (small-scale jets, or coronal counterpart of type-II spicules), which may play an important role in the supply of mass and energy to the hot corona. The other type of oscillation is usually associated with the upper part of loops. They are most clearly seen in the Doppler shift of coronal lines with forma- tion temperatures between one and two million degrees. The ...

Tian, Hui; Wang, Tongjiang; Ofman, Leon; De Pontieu, Bart; Innes, Davina E; Peter, Hardi

2012-01-01T23:59:59.000Z

73

Magnetoatmospheric oscillations in sunspot umbrae  

SciTech Connect (OSTI)

The nature of umbral oscillations is investigated using an empirical model for the sunspot umbra, based on the model of Maltby et al. (1986). Approximating the sunspot as a thick flux tube of circular cross section, the axisymmetric normal modes of magnetoatmospheric waves were determined, and a diagnostic diagram was generated for different field strengths. The diagram shows the existence of avoided crossings in the solution of magnetoatmospheric modes in a sunspot atmosphere. It was found that, for low values of the radial wavenumber k, corresponding to observed oscillations, a simple global classification is not possible. The oscillations in the low photosphere and below are of either fast or mixed type, but tend to acquire a slow or acoustic character above the temperature minimum. 61 refs.

Hasan, S.S. (Indian Institute of Astrophysics, Bangalore (India))

1991-01-01T23:59:59.000Z

74

The giant star of the symbiotic system YY Her: Rotation, Tidal wave, Solar-type cycle and Spots  

E-Print Network [OSTI]

We analyze the historical light curve of the symbiotic star YY Her, from 1890 up to December 2005. A secular declining trend is detected, at a rate of ~.01 magn in 1000 d, suggesting that the system could belong to the sub-class of symbiotic novae. Several outburst events are superposed on this slow decline. Three independent periodicities are identified in the light curve. A quasi-periodicity of 4650.7 d is detected for the outburst occurrence. We suggest that it is a signature of a solar-type magnetic dynamo cycle in the giant component. A period of 593.2 d modulates the quiescent light curve and it is identified as the binary period of the system. During outburst events the system shows a stable periodic oscillation of 551.4 d. We suggest that it is the rotation period of the giant.The secondary minima detected at some epochs of quiescence are probably due to dark spots on the surface of the rotating giant. The difference between the frequencies of these two last periods is the frequency of a tidal wave in the outer layers of the giant. A period which is a beat between the magnetic cycle and the tidal wave period is also apparent in the light curve. YY Her is a third symbiotic system exhibiting these cycles in their light curve, suggesting that a magnetic dynamo process is prevalent in the giant components of symbiotic stars, playing an important role in the outburst mechanism of some of these systems.

Liliana Formiggini; Elia M. Leibowitz

2006-09-17T23:59:59.000Z

75

Reflection type of terahertz imaging system using a high-T{sub c} superconducting oscillator  

SciTech Connect (OSTI)

A reflection type of imaging system is shown at sub-terahertz frequencies generated from high-T{sub c} superconducting intrinsic Josephson junction mesa structures fabricated by single crystalline Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+?} to demonstrate how the sub-terahertz imaging technique using monochromatic radiation is powerful and unique for the variety of practical applications. Several examples are discussed in detail and are compared to other terahertz imaging systems.

Kashiwagi, T.; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8571 (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Nakade, K.; Saiwai, Y.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8571 (Japan); Markovi?, B.; Mirkovi?, J. [Faculty of Sciences, University of Montenegro, George Washington Str., 81000 Podgorica (Montenegro); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Yamamoto, T. [National Institute for Materials Science, Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2014-01-13T23:59:59.000Z

76

Acoustic wave front reversal in a three-phase media  

E-Print Network [OSTI]

Acoustic wave front conjugation is studied in a sandy marine sediment that contains air bubbles in its fluid fraction. The considered phase conjugation is a four-wave nonlinear parametric sound interaction process caused by nonlinear bubble oscillations which are known to be dominant in acoustic nonlinear interactions in three-phase marine sediments. Two various mechanisms of phase conjugation are studied. One of them is based on the stimulated Raman-type sound scattering on resonance bubble oscillations. The second one is associated with sound interactions with bubble oscillations which frequencies are far from resonance bubble frequencies. Nonlinear equations to solve the wave-front conjugation problem are derived, expressions for acoustic wave amplitudes with a reversed wave front are obtained and compared for various frequencies of the excited bubble oscillations.

N. I. Pushkina

2015-03-05T23:59:59.000Z

77

Acoustic wave front conjugation in a three-phase media  

E-Print Network [OSTI]

Acoustic wave front reversal is studied in a sandy marine sediment that contains air bubbles in its fluid fraction. The considered phase conjugation is a four-wave nonlinear parametric sound interaction process caused by nonlinear bubble oscillations which are known to be dominant in acoustic nonlinear interactions in three-phase marine sediments. Two various mechanisms of phase conjugation are studied. One of them is based on the stimulated Raman-type sound scattering on resonance bubble oscillations. The second one is associated with sound interactions with bubble oscillations which frequencies are far from resonance bubble frequencies. Nonlinear equations to solve the wave-front conjugation problem are derived, expressions for acoustic wave amplitudes with a reversed wave front are obtained and compared for various frequencies of the excited bubble oscillations.

Pushkina, N I

2015-01-01T23:59:59.000Z

78

Oscillator detector  

SciTech Connect (OSTI)

An alien liquid detector employs a monitoring element and an oscillatory electronic circuit for maintaining the temperature of the monitoring element substantially above ambient temperature. The output wave form, eg., frequency of oscillation or wave shape, of the oscillatory circuit depends upon the temperaturedependent electrical characteristic of the monitoring element. A predetermined change in the output waveform allows water to be discriminated from another liquid, eg., oil. Features of the invention employing two thermistors in two oscillatory circuits include positioning one thermistor for contact with water and the other thermistor above the oil-water interface to detect a layer of oil if present. Unique oscillatory circuit arrangements are shown that achieve effective thermistor action with an economy of parts and energizing power. These include an operational amplifier employed in an astable multivibrator circuit, a discrete transistor-powered tank circuit, and use of an integrated circuit chip.

Potter, B.M.

1980-05-13T23:59:59.000Z

79

Dynamics of a horizontal cylinder oscillating as a wave energy converter about an off-centred axis.   

E-Print Network [OSTI]

The hydrodynamic properties of a horizontal cylinder which is free to pitch about an off-centred axis are studied and used to derive the equations of motion of a wave energy converter which extracts energy from incoming ...

Lucas, Jorge

2011-11-22T23:59:59.000Z

80

Gravitational waves emitted by solar-type stars excited by orbiting planets  

E-Print Network [OSTI]

The possibility of exciting the g-modes of a solar-type star as a consequence of the gravitational interaction with a close companion (a planet or a brown dwarf) is studied by a perturbative approach. The amplitude of the emitted gravitational wave is computed and compared with the quadrupole emission of the system, showing that in some cases it can be considerably larger. The effects of radiation reaction are considered to evaluate the timescale of the emission process, and a Roche lobe analysis is used to establish the region where the companion can orbit without being disrupted by tidal interactions with the star.

Emanuele Berti; Valeria Ferrari

2000-11-30T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Acoustic waves in a Biot-type porous snow model: The fast slow wave in light snow  

E-Print Network [OSTI]

Wave velocities, attenuation and reflection coefficients in snow can not be explained by the widely used elastic or viscoelastic models for wave propagation. Instead, Biot's model of wave propagation in porous materials should be used. However, the application of Biot's model is difficult due to the large property space of the underlying porous material. Here we use the properties of ice and air as well as empirical relationships to define the properties of snow as a function of porosity. This reduction allows to predict phase velocities and attenuation of the shear- and compressional-waves as functions of porosity or density. For light snow the peculiarity was found that the velocity of the compressional wave of the first kind is lower than the compressional wave of the second kind that is commonly referred to as the "slow" wave. The reversal of the velocities comes with an increase of attenuation for the first compressional wave. This is in line with the common observation that sound is strongly absorbed af...

Sidler, Rolf

2015-01-01T23:59:59.000Z

82

Waves  

E-Print Network [OSTI]

Waves is the supporting document to the Master of Fine Arts thesis exhibition of the same title. Exhibited March 7-12 2010 in the Art and Design Gallery at the University of Kansas, Waves was comprised of a series of mixed media drawings...

LaCure, Mari Mae

2010-04-29T23:59:59.000Z

83

Quantum Noise in Differential-type Gravitational-wave Interferometer and Signal Recycling  

E-Print Network [OSTI]

There exists the standard quantum limit (SQL), derived from Heisenberg's uncertainty relation, in the sensitivity of laser interferometer gravitational-wave detectors. However, in the context of a full quantum-mechanical approach, SQL can be overcome using the correlation of shot noise and radiation-pressure noise. So far, signal recycling, which is one of the methods to overcome SQL, is considered only in a recombined-type interferometer such as Advanced-LIGO, LCGT, and GEO600. In this paper, we investigated quantum noise and the possibility of signal recycling in a differential-type interferometer. As a result, we found that signal recycling is possible and creates at most three dips in the sensitivity curve of the detector. Then, taking advantage of the third additional dip and comparing the sensitivity of a differential-type interferometer with that of a next-generation Japanese GW interferometer, LCGT, we found that SNR of inspiral binary is improved by a factor of 1.43 for neutron star binary, 2.28 for 50 M_sun black hole binary, and 2.94 for 100 M_sun black hole binary. We also found that power recycling to increase laser power is possible in our signal-recycling configuration of a detector.

Atsushi Nishizawa; Seiji Kawamura; Masa-aki Sakagami

2007-06-03T23:59:59.000Z

84

Spin oscillations of relativistic fermions in the field of a traveling circularly polarized electromagnetic wave and a constant magnetic field  

E-Print Network [OSTI]

The Dirac equation, in the field of a traveling circularly polarized electromagnetic wave and a constant magnetic field, has singular solutions, corresponding the expansion of energy in vicinity of some singular point. These solutions described relativistic fermions. States relating to these solutions are not stationary. The temporal change of average energy, momentum and spin for single and mixed states is studied in the paper. A distinctive feature of the states is the disappearance of the longitudinal component of the average spin. Another feature is the equivalence of the condition of fermion minimal energy and the classical condition of the magnetic resonance. Finding such solutions assumes the use of a transformation for rotating and co-moving frames of references. Comparison studies of solutions obtained with the Galilean and non-Galilean transformation shown that some parameters of the non-Galilean transformation may be measured in high-energy physics.

Boris V. Gisin

2014-05-13T23:59:59.000Z

85

LSND neutrino oscillation results  

SciTech Connect (OSTI)

In the past several years, a number of experiments have searched for neutrino oscillations, where a neutrino of one type (say {bar {nu}}{sub {mu}}) spontaneously transforms into a neutrino of another type (say {bar {nu}}{sub e}). For this phenomenon to occur, neutrinos must be massive and the apparent conservation law of lepton families must be violated. In 1995 the LSND experiment published data showing candidate events that are consistent with {bar {nu}}{sub {mu}} oscillations. Additional data are reported here which provide stronger evidence for neutrino oscillations.

Louis, W.C.

1996-06-01T23:59:59.000Z

86

Wave propagation in a FitzHugh-Nagumo-type model with modified excitability E. P. Zemskov1,2,* and I. R. Epstein1,  

E-Print Network [OSTI]

Wave propagation in a FitzHugh-Nagumo-type model with modified excitability E. P. Zemskov1 I. INTRODUCTION Wave propagation and pattern formation in a variety of excitable media can-Lecar equations for neuronal activity. We obtain exact analytic solutions in the form of traveling waves using

Epstein, Irving R.

87

Gravity Waves Gravity Waves  

E-Print Network [OSTI]

;14/03/2014 6 H L H L L Phase & Group Velocity #12;14/03/2014 7 Doppler Effect #12;14/03/2014 8 Shock Waves #12;14/03/2014 14 Supernova Remnant Cassiopeia A Supernova blast waves #12;14/03/2014 15 Tycho's Remnant (SN 1572AD A SNR flythrough Theory of Supernova Blast Waves Supernovae: Type Ia Subsonic deflagration wave turning

Weijgaert, Rien van de

88

Novel type of chimera spiral waves arising from decoupling of a diffusible component Xiaodong Tang, Tao Yang, Irving R. Epstein, Yang Liu, Yuemin Zhao, and Qingyu Gao  

E-Print Network [OSTI]

Novel type of chimera spiral waves arising from decoupling of a diffusible component Xiaodong Tang (2014) Novel type of chimera spiral waves arising from decoupling of a diffusible component Xiaodong in chimera spirals grows drastically, leading to modulation and breakup of the spirals, in the transition

Epstein, Irving R.

89

A study of the self-oscillating jet impingement nozzle  

E-Print Network [OSTI]

wave and flow fluctuations that need no external input. The new oscillating jet when used for impingement surface transport was labeled the Self-Oscillating Jet Impingement Nozzle. The objectives of this research were to characterize the gains in heat...

Chinnock, Paul Scott

1993-01-01T23:59:59.000Z

90

Combustor oscillation pressure stabilizer  

SciTech Connect (OSTI)

In accordance with the objective of the present invention, the active control of unsteady combustion induced oscillations in a combustion chamber fired by a suitable fuel and oxidizer mixture, such as a hydrocarbon fuel and air mixture, is provided by restructuring and moving the position of the main flame front and thereby increasing the transport time and displacing the pressure wave further away from the in-phase relationship with the periodic heat release. The restructuring and repositioning of the main flame are achieved by utilizing a pilot flame which is pulsed at a predetermined frequency corresponding to less than about one-half the frequency of the combustion oscillation frequency with the duration of each pulse being sufficient to produce adequate secondary thermal energy to restructure the main flame and thereby decouple the heat release from the acoustic coupling so as to lead to a reduction in the dynamic pressure amplitude. The pulsating pilot flame produces a relatively small and intermittently existing flame front in the combustion zone that is separate from the oscillating main flame front but which provides the thermal energy necessary to effectively reposition the location of the oscillating main flame front out of the region in the combustion zone where the acoustic coupling can occur with the main flame and thereby effectively altering the oscillation-causing phase relationship with the heat of combustion.

Gemmen, R.S.; Richards, G.A.; Yip, M.T.J.; Robey, E.; Cully, S.R.; Addis, R.E.

1996-12-31T23:59:59.000Z

91

Gravitational waves in vacuum spacetimes with cosmological constant. I. Classification and geometrical properties of non-twisting type N solutions  

E-Print Network [OSTI]

All non-twisting Petrov-type N solutions of vacuum Einstein field equations with cosmological constant Lambda are summarized. They are shown to belong either to the non-expanding Kundt class or to the expanding Robinson-Trautman class. Invariant subclasses of each class are defined and the corresponding metrics are given explicitly in suitable canonical coordinates. Relations between the subclasses and their geometrical properties are analyzed. In the subsequent paper these solutions are interpreted as exact gravitational waves propagating in de Sitter or anti-de Sitter spacetimes.

J. Bicak; J. Podolsky

1999-07-13T23:59:59.000Z

92

Power oscillator  

DOE Patents [OSTI]

An oscillator includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

Gitsevich, Aleksandr (Montgomery Village, MD)

2001-01-01T23:59:59.000Z

93

Coherent states for the nonlinear harmonic oscillator  

SciTech Connect (OSTI)

Wave packets for the quantum nonlinear oscillator are considered in the generalized coherent state framework. To first order in the nonlinearity parameter the coherent state behaves very similar to its classical counterpart. The position expectation value oscillates in a simple harmonic manner. The energy-momentum uncertainty relation is time independent as in a harmonic oscillator. Various features (such as the squeezed state nature) of the coherent state have been discussed.

Ghosh, Subir [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 B. T. Road, Kolkata 700108 (India)

2012-06-15T23:59:59.000Z

94

Oscillator Architectures and Enhanced Frequency Synthesizer  

E-Print Network [OSTI]

A voltage controlled oscillator (VCO), that generates a periodic signal whose frequency is tuned by a voltage, is a key building block in any integrated circuit systems. A sine wave oscillator can be used for a built-in self testing where high...

Park, Sang Wook

2009-11-16T23:59:59.000Z

95

Neutrino optics and oscillations in gravitational fields  

E-Print Network [OSTI]

We study the propagation of neutrinos in gravitational fields using wave functions that are exact to first order in the metric deviation. For illustrative purposes, the geometrical background is represented by the Lense-Thirring metric. We derive explicit expressions for neutrino deflection, helicity transitions, flavor oscillations and oscillation Hamiltonian.

G. Lambiase; G. Papini; R. Punzi; G. Scarpetta

2005-03-07T23:59:59.000Z

96

Dirac oscillators and the relativistic R matrix  

E-Print Network [OSTI]

The Dirac oscillators are shown to be an excellent expansion basis for solutions of the Dirac equation by $R$-matrix techniques. The combination of the Dirac oscillator and the $R$-matrix approach provides a convenient formalism for reactions as well as bound state problems. The utility of the $R$-matrix approach is demonstrated in relativistic impulse approximation calculations where exchange terms can be calculated exactly, and scattering waves made orthogonal to bound state wave functions.

J. Grineviciute; Dean Halderson

2014-04-17T23:59:59.000Z

97

SPECTROSCOPIC OBSERVATIONS OF A CORONAL MORETON WAVE  

SciTech Connect (OSTI)

We observed a coronal wave (EIT wave) on 2011 February 16, using EUV imaging data from the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) and EUV spectral data from the Hinode/EUV Imaging Spectrometer (EIS). The wave accompanied an M1.6 flare that produced a surge and a coronal mass ejection (CME). EIS data of the wave show a prominent redshifted signature indicating line-of-sight velocities of {approx}20 km s{sup -1} or greater. Following the main redshifted wave front, there is a low-velocity period (and perhaps slightly blueshifted), followed by a second redshift somewhat weaker than the first; this progression may be due to oscillations of the EUV atmosphere set in motion by the initial wave front, although alternative explanations may be possible. Along the direction of the EIS slit the wave front's velocity was {approx}500 km s{sup -1}, consistent with its apparent propagation velocity projected against the solar disk as measured in the AIA images, and the second redshifted feature had propagation velocities between {approx}200 and 500 km s{sup -1}. These findings are consistent with the observed wave being generated by the outgoing CME, as in the scenario for the classic Moreton wave. This type of detailed spectral study of coronal waves has hitherto been a challenge, but is now possible due to the availability of concurrent AIA and EIS data.

Harra, Louise K. [UCL-Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom); Sterling, Alphonse C. [Space Science Office, VP62, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Goemoery, Peter [Astronomical Institute, Slovak Academy of Sciences, SK-05960 Tatranska Lomnica (Slovakia); Veronig, Astrid, E-mail: lkh@mssl.ucl.ac.uk, E-mail: alphonse.sterling@nasa.gov, E-mail: gomory@astro.s, E-mail: astrid.veronig@uni-graz.at [Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria)

2011-08-10T23:59:59.000Z

98

Autoresonant Excitation of Diocotron Waves  

E-Print Network [OSTI]

of the wave, the pump and the wave will phase lock at very low wave amplitude. When the pump reachesAutoresonant Excitation of Diocotron Waves J. Fajans E. Gilson U.C. Berkeley L. Friedland Hebrew of phase with the oscillator, and the os- cillator's amplitude will decrease, eventually reaching zero

Wurtele, Jonathan

99

Theoretical description based on general and exact nonextensive dispersion relations of plasma oscillation data and verification of new acoustic plasma waves  

SciTech Connect (OSTI)

In this paper, first we represent the differences between spatial and temporal dispersions and their dependence on the measurement techniques for electrostatic waves in unmagnetized collisionless plasma. Then, three different experimental data are compared to the solutions of exact nonextensive dispersion relations for electron-ion and pair plasma. The results confirm the existence of new acoustic plasma waves. Furthermore, these comparisons yield a Maxwellian and a nonextensive plasma with nonextensive parameter q larger than one, and a Maxwellian plasma with some abnormal dispersion properties.

Ebrahimi, V.; Esfandyari-Kalejahi, A. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 53714-161 Tabriz (Iran, Islamic Republic of)

2014-09-15T23:59:59.000Z

100

Moreton Waves and EIT Waves Related to the Flare Events of June 3, 2012 and July 6, 2012  

E-Print Network [OSTI]

We present geometrical and kinematical analysis of Moreton waves and EIT waves observed on June 3, 2012 and Moreton waves observed on July 6, 2012. The Moreton waves were recorded in H$\\alpha$ images of Global Oscillation Network Group (GONG) archive and EIT waves obtained from SDO/AIA observations, especially in 193 nm channel. The observed wave of June 3 has angular span of about $70^{\\circ}$ with a broad wave front associated to NOAA active region 11496. It was found that the speed of the wave that started propagating at 17.53 UT is between 950 to 1500 km/s. Related to this wave occurrence, there was solar type II and III radio bursts. The speed of the EIT in this respect about 247 km/sec. On the other hand, the wave of July 6 may be associated to X1.1 class flare that occurred at 23.01 UT around the 11514 active region. From the kinematical analysis, the wave propagated with the initial velocity of about 1180 km/s which is in agreement with coronal shock velocity derived from type II radio burst observati...

Admiranto, A G; Yus'an, U; Puspitaningrum, E

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

>300GHz Fixed-Frequency and Voltage-Controlled Fundamental Oscillators in an InP DHBT Process  

E-Print Network [OSTI]

>300GHz Fixed-Frequency and Voltage-Controlled Fundamental Oscillators in an InP DHBT Process, 93106, USA Abstract -- We report fundamental fixed-frequency and voltage-controlled oscillators bandwidth. Index Terms -- Millimeter-wave oscillators, voltage-controlled oscillators, MMIC oscillators. I

Rodwell, Mark J. W.

102

Computed tomography image using sub-terahertz waves generated from a high-T{sub c} superconducting intrinsic Josephson junction oscillator  

SciTech Connect (OSTI)

A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+?} was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications.

Kashiwagi, T., E-mail: kashiwagi@ims.tsukuba.ac.jp; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Nakade, K.; Saiwai, Y.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Yamamoto, T. [Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Markovi?, B. [Faculty of Sciences, University of Montenegro, George Washington Str., 81000 Podgorica (Montenegro); Mirkovi?, J. [Faculty of Science, University of Montenegro, and CETI, Put Radomira Ivanovica, 81000 Podgorica (Montenegro); Klemm, R. A. [Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816-2385 (United States)

2014-02-24T23:59:59.000Z

103

Dissipative kinetic Alfvén solitary waves resulting from viscosity  

SciTech Connect (OSTI)

Nonlinear small-amplitude kinetic Alfvén solitary waves (KASWs) are investigated with their “anomalous” kinetic viscosity effect on electrons. It is found that the structure of a hump-type KASW solution develops into a shock-type (or double layer) KASW solution for large amplitude KASWs when viscosity exists. For small amplitude KASWs, the Korteweg-de Vries (KdV) equation with an approximate pseudopotential was solved, and it is found that the hump-type KASWs develop into oscillating shock-type (kink-type) KASWs. It is also found that the oscillating scale of this structure is related to the propagation velocity and plasma beta, while the damping scale is inversely proportional to the viscosity.

Choi, C.-R.; Kang, S.-B.; Min, K.-W. [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)] [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Woo, M.-H. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Hwang, J.; Park, Y.-D. [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)

2013-11-15T23:59:59.000Z

104

Secondary dust density waves excited by nonlinear dust acoustic waves  

SciTech Connect (OSTI)

Secondary dust density waves were observed in conjunction with high amplitude (n{sub d}/n{sub d0}>2) dust acoustic waves (DAW) that were spontaneously excited in a dc glow discharge dusty plasma in the moderately coupled, {Gamma}{approx}1, state. The high amplitude dust acoustic waves produced large dust particle oscillations, displacements, and trapping. Secondary dust density waves were excited in the wave troughs of the high amplitude DAWs. The waveforms, amplitudes, wavelengths, and wave speeds of the primary DAWs and the secondary waves were measured. A dust-dust streaming instability is discussed as a possible mechanism for the production of the secondary waves.

Heinrich, J. R.; Kim, S.-H.; Meyer, J. K.; Merlino, R. L. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Rosenberg, M. [Department of Electrical and Computer Engineering, University of California, San Diego, California 92093 (United States)

2012-08-15T23:59:59.000Z

105

Jin and Zhang 1 PARAMICS SIMULATION OF PERIODIC OSCILLATIONS CAUSED BY  

E-Print Network [OSTI]

and global. Finally, consistencies between a macroscopic kinematic wave model and Paramics are discussed-based kinematic wave model, the mechanism of such oscillations is revealed as follows: (i) When two traffic and Zhang 2 ABSTRACT Traffic oscillations such as stop-and-go waves in a traffic system can be caused

Mease, Kenneth D.

106

Autoresonance energy transfer versus localization in weakly coupled oscillators  

E-Print Network [OSTI]

In this paper we investigate the distribution of energy between weakly coupled linear and nonlinear oscillators in a two-degree-of-freedom (2D) system. Two classes of problems are studied analytically and numerically: (1) a periodic force with constant frequency is applied to the nonlinear (Duffing) oscillator with slowly time-decreasing linear stiffness; (2) the time-independent nonlinear oscillator is excited by a force with slowly increasing frequency. In both cases, stiffness of the attached linear oscillator and linear coupling remain constant, and the system is initially engaged in resonance. This paper demonstrates that in the systems of the first type autoresonance (AR) occurs in both oscillators while in systems of the second type AR occurs only in the excited nonlinear oscillator but the coupled linear oscillator exhibits small bounded oscillations. Considering slow detuning, we obtain explicit asymptotic approximations for the amplitudes and the phases of oscillations close to exact (numerical) results.

Agnessa Kovaleva; Leonid Manevitch

2014-10-22T23:59:59.000Z

107

Stable local oscillator microcircuit.  

SciTech Connect (OSTI)

This report gives a description of the development of a Stable Local Oscillator (StaLO) Microcircuit. The StaLO accepts a 100MHz input signal and produces output signals at 1.2, 3.3, and 3.6 GHz. The circuit is built as a multi-chip module (MCM), since it makes use of integrated circuit technologies in silicon and lithium niobate as well as discrete passive components. The StaLO uses a comb generator followed by surface acoustic wave (SAW) filters. The comb generator creates a set of harmonic components of the 100MHz input signal. The SAW filters are narrow bandpass filters that are used to select the desired component and reject all others. The resulting circuit has very low sideband power levels and low phase noise (both less than -40dBc) that is limited primarily by the phase noise level of the input signal.

Brocato, Robert Wesley

2006-10-01T23:59:59.000Z

108

Low-frequency oscillations of forced barotropic flow  

SciTech Connect (OSTI)

Jin and Ghil demonstrate that for topographically resonant flow, low-frequency finite-amplitude oscillations may arise from wave -- wave interactions and topographic form drag. Their model is extended to include a zonally asymmetric vorticity source, which is shown to interact with the perturbation field to produce zonally rectified wave fluxes that dramatically alter the Hopf bifurcation from stationary solutions to low-frequency oscillations. The frequency, intensity, and general character of these oscillations are shown to depend crucially upon the phasing and relative strength of the forcings.

Nathan, T.R.; Barcilon, A. (Univ. of California, Davis, CA (United States) The Florida State Univ., Tallahassee, FL (United States))

1994-02-01T23:59:59.000Z

109

Effects of liquid pore water on acoustic wave propagation in snow as a Biot-type porous material  

E-Print Network [OSTI]

A method to estimate phase velocity and attenuation of acoustic waves in the presence of liquid water in a snowpack is presented. The method is based on Biot's theory of wave propagation in porous materials. Empirical relations and a priori information is used to characterize snow as a porous material as a function of porosity. Plane wave theory and an equivalent pore fluid are used to solve Biot's differential equations and to asses the impact of the air and water in the pore space. The liquid water in the pore space of a snow pack reduces the velocity of the first compressional wave by roughly 300 m/s for every 0.1 increase in liquid water saturation. Also the attenuation of the compressional waves is increased with increasing liquid water content. Two end member models for compaction are evaluated to asses the importance of an independent density measurement for an estimate of liquid pore water saturation in snow with acoustic waves. The two end members correspond to no compaction at all and to a melting s...

Sidler, Rolf

2015-01-01T23:59:59.000Z

110

Angular momentum extraction by gravity waves in the Sun  

E-Print Network [OSTI]

We review the behavior of the oscillating shear layer produced by gravity waves below the surface convection zone of the Sun. We show that, under asymmetric filtering produced by this layer, gravity waves of low spherical order, which are stochastically excited at the base of the convection zone of late type stars, can extract angular momentum from their radiative interior. The time-scale for this momentum extraction in a Sun-like star is of the order of 10^7 years. The process is particularly efficient in the central region, and it could produce there a slowly rotating core.

Suzanne Talon; Pawan Kumar; Jean-Paul Zahn

2002-06-27T23:59:59.000Z

111

Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino  

E-Print Network [OSTI]

Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino Department of Physics and Astronomy with their announcement that: "We find that a new type of sound wave, namely, the dust-acoustic waves, can appear" [1 and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some

Merlino, Robert L.

112

Umbral oscillations as a probe of sunspot  

SciTech Connect (OSTI)

The interaction of the solar five-minute oscillations with a sunspot is thoroughly explored, both on observational and theoretical grounds. Simple theoretical models are developed in order to understand the observations of umbral oscillations. Observations made at the National Solar Observatory detected both the three-minute and five-minute umbral oscillations at photospheric heights. The three-minute oscillations were found to have a kinetic energy density six times higher in the photosphere than in the chromosphere and to be concentrated in the central part of the umbra, supporting the photospheric resonance theory for the three-minute umbral oscillations. The five-minute oscillations are attenuated in the umbra, which appears to act as a filter in selecting some of the peaks in the power spectrum of five-minute oscillations in the surrounding photosphere. The k-omega power spectrum of the umbral oscillations shows a shift of power to longer wavelengths. Theoretical models of the transmission of acoustic waves into a magnetic region explain both observed effects.

Abdelatif, T.E.H.

1985-01-01T23:59:59.000Z

113

Oscillations in glow discharges  

E-Print Network [OSTI]

OSCILLATIONS IN GLOW DISCHARGES A Dissertation By Tom Prickett, Jr. June 1950 Approved as to style and content by Chairman of Committee OSCILLATIONS IN GLOW DISCHARGES A Dissertation By Tom Prickett, Jr* June 1950 OSCILLATIONS IN GLOW... 1950 CONTENTS Introduction ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 1 I. Review of Plasma Oscillations in Gas Discharges ? . . 2 II. Review of Relaxation Processes in Gas Discharges ? . 13 III. Report of Laboratory Investigation...

Prickett, Tom

1950-01-01T23:59:59.000Z

114

High speed electrical power takeoff for oscillating water columns   

E-Print Network [OSTI]

This thesis describes research into electrical power takeoff mechanisms for Oscillating Water Column (OWC) wave energy devices. The OWC application is studied and possible alternatives to the existing Induction Generator ...

Hodgins, Neil

2010-01-01T23:59:59.000Z

115

Influence of flavor oscillations on neutrino beam instabilities  

SciTech Connect (OSTI)

We consider the collective neutrino plasma interactions and study the electron plasma instabilities produced by a nearly mono-energetic neutrino beam in a plasma. We describe the mutual interaction between neutrino flavor oscillations and electron plasma waves. We show that the neutrino flavor oscillations are not only perturbed by electron plasmas waves but also contribute to the dispersion relation and the growth rates of neutrino beam instabilities.

Mendonça, J. T., E-mail: titomend@ist.utl.pt [Instituto de Física, Universidade de São Paulo, 05508-090 São Paulo SP (Brazil); Haas, F. [Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre RS (Brazil); Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain and Instituto de Investigaciones Energeticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain)

2014-09-15T23:59:59.000Z

116

Propagating waves mediate information transfer in the motor cortex  

E-Print Network [OSTI]

Propagating waves mediate information transfer in the motor cortex Doug Rubino1, Kay A Robbins2-delay reaching task, we found that these oscillations propagated as waves across the surface of the motor cortex oscillations propagated as waves across the primary motor (MI) and premotor (PMd) cortices as monkeys planned

Hatsopoulos, Nicholas

117

A performance study of plane wave finite element methods with a Pad-type artificial boundary condition in acoustic scattering  

E-Print Network [OSTI]

Keywords: Acoustic scattering Finite element Plane wave Pollution High-frequency Artificial boundary condition in acoustic scattering R. Kechroud a , A. Soulaimani a , X. Antoine b,c,* a �cole de Technologie are found. Indeed, it is well known that pollution effects [10­12] arise in the standard FEM, limiting its

Antoine, Xavier - Institut de Mathématiques �lie Cartan, Université Henri Poincaré

118

Three-dimensional instability of dust ion-acoustic solitary waves in a magnetized dusty plasma with two different types of nonisothermal electrons  

SciTech Connect (OSTI)

The nonlinear propagation of dust ion-acoustic solitary waves (DIASWs) in a magnetized dusty plasma which consists of two different types of nonisothermal electrons, hot adiabatic inertial ions fluid and immobile negatively charged dust particles is studied. The modified Zakharov-Kuznetsov (MZK) equation, describing the small but finite amplitude DIASWs, is derived using a reductive perturbation method. The combined effects of the external magnetic field, obliqueness (i.e., the propagation angle), and the two-temperature nonisothermal electrons, which are found to significantly modify the basic properties of DIASWs, are explicitly examined. The three-dimensional instability of DIASWs is also analyzed using the small-k (long wavelength plane wave) perturbation expansion technique. The results show that the external magnetic field, the propagation angle, and the two-temperature nonisothermal electrons have strong effects on the instability criterion as well as the growth rate.

Shalaby, M.; Khaled, M. A. [Department of Physics, Faculty of Science, Ain Shams University, Cairo, 11566 (Egypt); EL-Labany, S. K.; EL-Shamy, E. F. [Department of Physics, Faculty of Science, Mansoura University, Damietta Branch, Damietta El-Gedida 34517 (Egypt)

2010-11-15T23:59:59.000Z

119

Multigraph Conditions for Multistability, Oscillations  

E-Print Network [OSTI]

[10]. Some common biochemical oscillators, such as calcium oscillations [11] and glycolytic of both. Many biochemical oscillator models contain an auto- catalytic loop, which occurs when

Craciun, Gheorghe

120

Phenomenology of Neutrino Oscillations  

E-Print Network [OSTI]

The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

G. Rajasekaran

2000-04-17T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
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121

Optoelectronic Oscillator Based on Fiber Ring Resonator: Overall System Optimization and Phase  

E-Print Network [OSTI]

Optoelectronic Oscillator Based on Fiber Ring Resonator: Overall System Optimization and Phase of an optoelectronic oscillator based on a passive fiber ring resonator. Our experimental results demonstrate existing oscillator of the same type, an active cavity based coupled optoelectronic oscillator. I

Paris-Sud XI, Université de

122

Gravitational waves in vacuum spacetimes with cosmological constant. II. Deviation of geodesics and interpretation of non-twisting type N solutions  

E-Print Network [OSTI]

In a suitably chosen essentially unique frame tied to a given observer in a general spacetime, the equation of geodesic deviation can be decomposed into a sum of terms describing specific effects: isotropic (background) motions associated with the cosmological constant, transverse motions corresponding to the effects of gravitational waves, longitudinal motions, and Coulomb-type effects. Conditions under which the frame is parallelly transported along a geodesic are discussed. Suitable coordinates are introduced and an explicit coordinate form of the frame is determined for spacetimes admitting a non-twisting null congruence. Specific properties of all non-twisting type N vacuum solutions with cosmological constant Lambda (non-expanding Kundt class and expanding Robinson-Trautman class) are then analyzed. It is demonstrated that these spacetimes can be understood as exact transverse gravitational waves of two polarization modes "+" and "x", shifted by pi/4, which propagate "on" Minkowski, de Sitter, or anti-de Sitter backgrounds. It is also shown that the solutions with Lambda>0 may serve as exact demonstrations of the cosmic "no-hair" conjecture in radiative spacetimes with no symmetry.

J. Bicak; J. Podolsky

1999-07-13T23:59:59.000Z

123

Modified semi-classical methods for nonlinear quantum oscillations problems  

SciTech Connect (OSTI)

We develop a modified semi-classical approach to the approximate solution of Schroedinger's equation for certain nonlinear quantum oscillations problems. In our approach, at lowest order, the Hamilton-Jacobi equation of the conventional semi-classical formalism is replaced by an inverted-potential-vanishing-energy variant thereof. With suitable smoothness, convexity and coercivity properties imposed on its potential energy function, we prove, using methods drawn from the calculus of variations together with the (Banach space) implicit function theorem, the existence of a global, smooth 'fundamental solution' to this equation. Higher order quantum corrections thereto, for both ground and excited states, can then be computed through the integration of associated systems of linear transport equations, derived from Schroedinger's equation, and formal expansions for the corresponding energy eigenvalues obtained therefrom by imposing the natural demand for smoothness on the (successively computed) quantum corrections to the eigenfunctions. For the special case of linear oscillators our expansions naturally truncate, reproducing the well-known exact solutions for the energy eigenfunctions and eigenvalues. As an explicit application of our methods to computable nonlinear problems, we calculate a number of terms in the corresponding expansions for the one-dimensional anharmonic oscillators of quartic, sectic, octic, and dectic types and compare the results obtained with those of conventional Rayleigh/Schroedinger perturbation theory. To the orders considered (and, conjecturally, to all orders) our eigenvalue expansions agree with those of Rayleigh/Schroedinger theory whereas our wave functions more accurately capture the more-rapid-than-gaussian decay known to hold for the exact solutions to these problems. For the quartic oscillator in particular our results strongly suggest that both the ground state energy eigenvalue expansion and its associated wave function expansion are Borel summable to yield natural candidates for the actual exact ground state solution and its energy. Our techniques for proving the existence of the crucial 'fundamental solution' to the relevant (inverted-potential-vanishing-energy) Hamilton-Jacobi equation have the important property of admitting interesting infinite dimensional generalizations. In a project paralleling the present one we shall show how this basic construction can be carried out for the Yang-Mills equations in Minkowski spacetime.

Moncrief, Vincent [Department of Physics and Department of Mathematics, Yale University, P.O. Box 208120, New Haven, Connecticut 06520 (United States); Marini, Antonella [Department of Mathematics, Yeshiva University, 500 West 185th Street, New York, New York 10033, USA and Department of Mathematics, University of L'Aquila, Via Vetoio, 67010 L'Aquila, AQ (Italy); Maitra, Rachel [Department of Physics, Albion College, 611 E. Porter Street, Albion, Michigan 49224 (United States)

2012-10-15T23:59:59.000Z

124

Non-linear Langmuir waves in a warm quantum plasma  

SciTech Connect (OSTI)

A non-linear differential equation describing the Langmuir waves in a warm quantum electron-ion plasma has been derived. Its numerical solutions of the equation show that ordinary electronic oscillations, similar to the classical oscillations, occur along with small-scale quantum Langmuir oscillations induced by the Bohm quantum force.

Dubinov, Alexander E., E-mail: dubinov-ae@yandex.ru; Kitaev, Ilya N. [Russian Federal Nuclear Center—All-Russia Scientific and Research Institute of Experimental Physics (RFNC-VNIIEF), 37 Mira Ave., Nizhny Novgorod region, Sarov 607188 (Russian Federation); Sarov State Institute of Physics and Technology (SarFTI), National Research Nuclear University MEPhI, 607186 Sarov, Nizhny Novgorod region (Russian Federation)

2014-10-15T23:59:59.000Z

125

Analytical solutions for energy spectra of electrons accelerated by nonrelativistic shock-waves in shell type supernova remnants  

E-Print Network [OSTI]

%context {Recent observations of hard X-rays and very high energy gamma-rays from a number of young shell type supernova remnants indicate the importance of detailed quantitative studies of energy spectra of relativistic electrons formed via diffusive shock acceleration accompanied by intense nonthermal emission through synchrotron radiation and inverse Compton scattering.} %aim {The aim of this work was derivation of exact asymptotic solutions of the kinetic equation which describes the energy distribution of shock-accelerated electrons for an arbitrary energy-dependence of the diffusion coefficient.} %method {The asymptotic solutions at low and very high energy domains coupled with numerical calculations in the intermediate energy range allow analytical presentations of energy spectra of electrons for the entire energy region.} %results {Under the assumption that the energy losses of electrons are dominated by synchrotron cooling, we derived the exact asymptotic spectra of electrons without any restriction on the diffusion coefficient. We also obtained simple analytical approximations which describe, with accuracy better than ten percent, the energy spectra of nonthermal emission of shock-accelerated electrons due to the synchrotron radiation and inverse Compton scattering.} %conclusions {The results can be applied for interpretation of X-ray and gamma-ray observations of shell type supernova remnants, as well as other nonthermal high energy source populations like microquasars and large scale synchrotron jets of active galactic nuclei.

V. N. Zirakashvili; F. Aharonian

2007-10-26T23:59:59.000Z

126

Electromagnetic waves and Stokes parameters in the wake of a gravitational wave  

E-Print Network [OSTI]

A theoretical description of electromagnetic waves in the background of a (weak) gravitational wave is presented. Explicit expressions are obtained for the Stokes parameters during the passage of a plane-fronted gravitational wave described by the Ehlers-Kundt metric. In particular, it is shown that the axis of the polarization ellipse oscillates, its ellipticity remaining constant.

Shahen Hacyan

2012-06-15T23:59:59.000Z

127

Active-bridge oscillator  

DOE Patents [OSTI]

An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.

Wessendorf, Kurt O. (Albuquerque, NM)

2001-01-01T23:59:59.000Z

128

New wave generation  

E-Print Network [OSTI]

We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (2007). This mechanism, which involves a tunable source comprised of oscillating plates, has so far been used for a few fundamental studies of internal waves, but its full potential has yet to be realized. Our studies reveal that this approach is capable of producing a wide variety of two-dimensional wave fields, including plane waves, wave beams and discrete vertical modes in finite-depth stratifications. The effects of discretization by a finite number of plates, forcing amplitude and angle of propagation are investigated, and it is found that the method is remarkably efficient at generating a complete wave field despite forcing only one velocity component in a controllable manner. We furthermore find that the nature of the radiated wave field is well predicted using Fourier transforms of the spatial structure of the wave generator.

Mercier, Matthieu J; Mathur, Manikandan; Gostiaux, Louis; Peacock, Thomas; Dauxois, Thierry

2015-01-01T23:59:59.000Z

129

Neutrino oscillations: Quantum mechanics vs. quantum field theory  

SciTech Connect (OSTI)

A consistent description of neutrino oscillations requires either the quantum-mechanical (QM) wave packet approach or a quantum field theoretic (QFT) treatment. We compare these two approaches to neutrino oscillations and discuss the correspondence between them. In particular, we derive expressions for the QM neutrino wave packets from QFT and relate the free parameters of the QM framework, in particular the effective momentum uncertainty of the neutrino state, to the more fundamental parameters of the QFT approach. We include in our discussion the possibilities that some of the neutrino's interaction partners are not detected, that the neutrino is produced in the decay of an unstable parent particle, and that the overlap of the wave packets of the particles involved in the neutrino production (or detection) process is not maximal. Finally, we demonstrate how the properly normalized oscillation probabilities can be obtained in the QFT framework without an ad hoc normalization procedure employed in the QM approach.

Akhmedov, Evgeny Kh.; Kopp, Joachim; ,

2010-01-01T23:59:59.000Z

130

Ferromagnetic Resonance of Micro- and Nano-sized Hexagonal Ferrite Powders at Millimeter Waves  

SciTech Connect (OSTI)

Complex magnetic permeability and dielectric permittivity of micro- and nano-sized powdered barium (BaFe{sub 12}O{sub 19}) and strontium (SrFe{sub 12}O{sub 19}) hexaferrites have been studied in a broadband millimeter wave frequency range (30-120 GHz). Transmittance measurements have been performed using a free space quasi-optical millimeter wave spectrometer, equipped with a set of high power backward wave oscillators. Real and imaginary parts of dielectric permittivity for both types of micro- and nanoferrites have been calculated using analysis of recorded high precision transmittance spectra. Frequency dependences of the magnetic permeability have been obtained from Schloemann's equation for partially magnetized ferrites. These materials show promise as tunable millimeter wave absorber, based on their size-dependent absorption.

Korolev, Konstantin A.; McCloy, John S.; Afsar, Mohammed N.

2012-02-22T23:59:59.000Z

131

Neutrino oscillations: Entanglement, energy-momentum conservation and QFT  

E-Print Network [OSTI]

We consider several subtle aspects of the theory of neutrino oscillations which have been under discussion recently. We show that the $S$-matrix formalism of quantum field theory can adequately describe neutrino oscillations if correct physics conditions are imposed. This includes space-time localization of the neutrino production and detection processes. Space-time diagrams are introduced, which characterize this localization and illustrate the coherence issues of neutrino oscillations. We discuss two approaches to calculations of the transition amplitudes, which allow different physics interpretations: (i) using configuration-space wave packets for the involved particles, which leads to approximate conservation laws for their mean energies and momenta; (ii) calculating first a plane-wave amplitude of the process, which exhibits exact energy-momentum conservation, and then convoluting it with the momentum-space wave packets of the involved particles. We show that these two approaches are equivalent. Kinematic entanglement (which is invoked to ensure exact energy-momentum conservation in neutrino oscillations) and subsequent disentanglement of the neutrinos and recoiling states are in fact irrelevant when the wave packets are considered. We demonstrate that the contribution of the recoil particle to the oscillation phase is negligible provided that the coherence conditions for neutrino production and detection are satisfied. Unlike in the previous situation, the phases of both neutrinos from $Z^0$ decay are important, leading to a realization of the Einstein-Podolsky-Rosen paradox.

E. Kh. Akhmedov; A. Yu. Smirnov

2010-10-27T23:59:59.000Z

132

Neutrino Oscillation Physics  

E-Print Network [OSTI]

To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures.

Boris Kayser

2013-12-25T23:59:59.000Z

133

Driven harmonic oscillator as a quantum simulator for open systems  

E-Print Network [OSTI]

We show theoretically how a driven harmonic oscillator can be used as a quantum simulator for non-Markovian damped harmonic oscillator. In the general framework, the results demonstrate the possibility to use a closed system as a simulator for open quantum systems. The quantum simulator is based on sets of controlled drives of the closed harmonic oscillator with appropriately tailored electric field pulses. The non-Markovian dynamics of the damped harmonic oscillator is obtained by using the information about the spectral density of the open system when averaging over the drives of the closed oscillator. We consider single trapped ions as a specific physical implementation of the simulator, and we show how the simulator approach reveals new physical insight into the open system dynamics, e.g. the characteristic quantum mechanical non-Markovian oscillatory behavior of the energy of the damped oscillator, usually obtained by the non-Lindblad-type master equation, can have a simple semiclassical interpretation.

Jyrki Piilo; Sabrina Maniscalco

2006-10-03T23:59:59.000Z

134

Oscillating fluid power generator  

SciTech Connect (OSTI)

A system and method for harvesting the kinetic energy of a fluid flow for power generation with a vertically oriented, aerodynamic wing structure comprising one or more airfoil elements pivotably attached to a mast. When activated by the moving fluid stream, the wing structure oscillates back and forth, generating lift first in one direction then in the opposite direction. This oscillating movement is converted to unidirectional rotational movement in order to provide motive power to an electricity generator. Unlike other oscillating devices, this device is designed to harvest the maximum aerodynamic lift forces available for a given oscillation cycle. Because the system is not subjected to the same intense forces and stresses as turbine systems, it can be constructed less expensively, reducing the cost of electricity generation. The system can be grouped in more compact clusters, be less evident in the landscape, and present reduced risk to avian species.

Morris, David C

2014-02-25T23:59:59.000Z

135

Scholte waves generated by seafloor topography  

E-Print Network [OSTI]

Seafloor topography can excite strong interface waves called Scholte waves that are often dispersive and characterized by slow propagation but large amplitude. This type of wave can be used to invert for near seafloor shear ...

Zheng, Yingcai

2012-01-01T23:59:59.000Z

136

Microdomain calcium oscillations in Drosophila glia regulate seizure susceptibility and require NCKX  

E-Print Network [OSTI]

Glial cells exhibit spontaneous and activity-dependent fluctuations in intracellular Ca²+, yet it is unclear whether glial Ca²+ oscillations are required during neuronal signaling. Somatic glial Ca²+ waves are primarily ...

Melom, Jan E. (Jan Elizabeth)

2013-01-01T23:59:59.000Z

137

Possible new wave phenomena in the brain  

E-Print Network [OSTI]

We propose to search for new wave phenomena in the brain by using interference effects in analogy to the well-known double slit (Young) experiment. This method is able to extend the range of oscillation frequencies to much higher values than currently accessible. It is argued that such experiments may test the hypothesis of the wave nature of information coding.

Jerzy Szwed

2009-08-10T23:59:59.000Z

138

Investigation in acousto-optic laser stabilization for crystal resonator based optoelectronic oscillators  

E-Print Network [OSTI]

1 Investigation in acousto-optic laser stabilization for crystal resonator based optoelectronic to stabilize a microwave signal generated by an optoelectronic oscillator (OEO). Bulk acoustic waves at two is operating for any resonator to be inserted into the optoelectronic oscillator with a Q factor in the range 2

Paris-Sud XI, Université de

139

Angular momentum and energy structure of the coherent state of a 2D isotropic harmonic oscillator  

E-Print Network [OSTI]

The angular momentum structure and energy structure of the coherent state of a 2D isotropic harmonic oscillator were investigated. Calculations showed that the average values of angular momentum and energy (except the zero point energy) of this nonspreading 2D wave packet are identical to those of the corresponding classical oscillator moving along a circular or an elliptic orbit.

LIU Yufeng; HUO Wujun; ZENG Jinyan

1999-12-03T23:59:59.000Z

140

The impact of bubble diffusivity on confined oscillated bubbly liquid Sergey Shklyaev1  

E-Print Network [OSTI]

their volume. In other words, in a liquid containing bubbles the speed of sound cb can b oscillations4,5 to the frequency of external driving. Here, k= /c0 is the wave number, c0 is the speed of soundThe impact of bubble diffusivity on confined oscillated bubbly liquid Sergey Shklyaev1 and Arthur V

Straube, Arthur V.

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

GEOPHYSICAL FLUID DYNAMICS-I OC512/AS509 2011 P.Rhines 19-21 Jan 2011 LECTUREs 7-8: Dynamics of a single-layer fluid: waves, inertial oscillations, and  

E-Print Network [OSTI]

-water' balance in a homogeneous fluid. The MASS conservation equation for a constant density fluid implies.1-7.6 (began last week), 10.4 (Kelvin waves) (similar material in Vallis §§ 2.8, 3.1, 3.6-3.8 Bretherton than a fraction of a wavelength. This is implicit in a scale analysis of the governing equation

142

Driven synchronization in random networks of oscillators  

E-Print Network [OSTI]

Synchronization is a universal phenomenon found in many non-equilibrium systems. Much recent interest in this area has overlapped with the study of complex networks, where a major focus is determining how a system's connectivity patterns affect the types of behavior that it can produce. Thus far, modeling efforts have focused on the tendency of networks of oscillators to mutually synchronize themselves, with less emphasis on the effects of external driving. In this work we discuss the interplay between mutual and driven synchronization in networks of phase oscillators of the Kuramoto type, and resolve how the structure and emergence of such states depends on the underlying network topology for simple random networks with a given degree distribution. We provide a partial bifurcation analysis, centering on the appearance of a Takens-Bogdanov-Cusp singularity, which broadly separates homogeneous and heterogeneous network behavior in a weak coupling limit, and from which the number, stability and appearance of driven and mutually synchronized states can be determined, as a function of a few parameters. We find transitions such as Saddle-Node-Infinite-Periods, Limit-Point-of-Cycles, and Hopf bifurcations (both branches), as well as multiple bistability regions and dynamics that differ for the network types. This description is connected to the underlying dynamics of oscillator clusters for important states and transitions. Our results can provide a basis for studying the problem of frequency controlling disordered oscillator networks.

Jason Hindes; Christopher R. Myers

2015-02-28T23:59:59.000Z

143

Weak chimeras in minimal networks of coupled phase oscillators  

E-Print Network [OSTI]

We suggest a definition for a type of chimera state that appears in networks of indistinguishable phase oscillators. Defining a "weak chimera" as a type of invariant set showing partial frequency synchronization, we show that this means they cannot appear in phase oscillator networks that are either globally coupled or too small. We exhibit various networks of four, six and ten indistinguishable oscillators where weak chimeras exist with various dynamics and stabilities. We examine the role of Kuramoto-Sakaguchi coupling in giving degenerate (neutrally stable) families of weak chimera states in these example networks.

Peter Ashwin; Oleksandr Burylko

2014-12-10T23:59:59.000Z

144

A Model of Intra-seasonal Oscillations in the Earth atmosphere  

E-Print Network [OSTI]

We suggest a way of rationalizing an intra-seasonal oscillations (IOs) of the Earth atmospheric flow as four meteorological relevant triads of interacting planetary waves, isolated from the system of all the rest planetary waves. Our model is independent of the topography (mountains, etc.) and gives a natural explanation of IOs both in the North and South Hemispheres. Spherical planetary waves are an example of a wave mesoscopic system obeying discrete resonances that also appears in other areas of physics.

Elena Kartashova; Victor S. L'vov

2007-04-04T23:59:59.000Z

145

Sunspot umbral oscillations in the photosphere and low chromosphere  

SciTech Connect (OSTI)

Velocity oscillations in sunspot umbrae were measured simultaneously in two spectral lines, one formed in the low photosphere and the other formed in the low chromosphere, just above the temperature minimum. The power spectrum of velocity in each spectral line shows the presence of both 5 minute and 3 minute oscillations. The coherence spectrum and phase spectrum between the velocities in the two lines show that the 3 minute umbral oscillation has the character of a coherent, vertically standing wave in the photosphere. Also, the kinetic energy density of the 3 minute oscillation is found to be at least 5 times greater in the low photosphere than in the low chromosphere. These results indicate that the fundamental 3 minute umbral oscillation is caused by a photospheric resonance rather than a chromospheric resonance. Multiple peaks in the power spectrum of chromospheric velocity at periods near 3 minutes may be caused by the additional effect of a chromospheric resonance. The umbral 5 minute oscillations are coherent between the two heights, with a small, positive phase difference between the low photosphere and low chromosphere, much the same as in the quiet Sun. A negative phase difference at frequencies around 2 mHz suggests the presence of gravity waves in the umbra.

Lites, B.W.; Thomas, J.H.

1985-07-15T23:59:59.000Z

146

Non-linear numerical simulations of magneto-acoustic wave propagation in small-scale flux tubes  

E-Print Network [OSTI]

We present results of non-linear, 2D, numerical simulations of magneto-acoustic wave propagation in the photosphere and chromosphere of small-scale flux tubes with internal structure. Waves with realistic periods of three to five minutes are studied, after applying horizontal and vertical oscillatory perturbations to the equilibrium model. Spurious reflections of shock waves from the upper boundary are minimized thanks to a special boundary condition. This has allowed us to increase the duration of the simulations and to make it long enough to perform a statistical analysis of oscillations. The simulations show that deep horizontal motions of the flux tube generate a slow (magnetic) mode and a surface mode. These modes are efficiently transformed into a slow (acoustic) mode in the vA propagates vertically along the field lines, forms shocks and remains always within the flux tube. It might deposit effectively the energy of the driver into the chromosphere. When the driver oscillates with a high frequency, above the cut-off, non-linear wave propagation occurs with the same dominant driver period at all heights. At low frequencies, below the cut-off, the dominant period of oscillations changes with height from that of the driver in the photosphere to its first harmonic (half period) in the chromosphere. Depending on the period and on the type of the driver, different shock patterns are observed.

E. Khomenko; M. Collados; T. Felipe

2008-01-25T23:59:59.000Z

147

The concept of waves is an integral part of our scientif-ic culture and has nourished physicists, pure and  

E-Print Network [OSTI]

, oscillations of diffusing energy or particles. They have complex wave vectors and do not exhibit square), or an oscillating charge carrier density (such as a har- monically-photoexcited carrier plasma wave in a semicon it is absorbed by the medium. For thermal waves, there is usually no delay in the energy conversion process, so F

Mandelis, Andreas

148

TIME-PERIODIC SOUND WAVE PROPAGATION COMPRESSIBLE EULER EQUATIONS  

E-Print Network [OSTI]

A PARADIGM FOR TIME-PERIODIC SOUND WAVE PROPAGATION IN THE COMPRESSIBLE EULER EQUATIONS BLAKE consistent with time-periodic sound wave propagation in the 3 Ã? 3 nonlinear compressible Euler equations description of shock-free waves that propagate through an oscillating entropy field without breaking or dis

149

Experimental studies of the hydrodynamic characteristics of a sloped wave energy device   

E-Print Network [OSTI]

Many wave energy convertors are designed to use either vertical (heave) or horizontal (surge) movements of waves. But the frequency response of small heaving buoys and oscillating water column devices shows that they are ...

Lin, Chia-Po

2000-07-19T23:59:59.000Z

150

Primordial Gravitational Waves Enhancement  

E-Print Network [OSTI]

We reconsider the enhancement of primordial gravitational waves that arises from a quantum gravitational model of inflation. A distinctive feature of this model is that the end of inflation witnesses a brief phase during which the Hubble parameter oscillates in sign, changing the usual Hubble friction to anti-friction. An earlier analysis of this model was based on numerically evolving the graviton mode functions after guessing their initial conditions near the end of inflation. The current study is based on an equation which directly evolves the normalized square of the magnitude. We are also able to make a very reliable estimate for the initial condition using a rapidly converging expansion for the sub-horizon regime. Results are obtained for the energy density per logarithmic wave number as a fraction of the critical density. These results exhibit how the enhanced signal depends upon the number of oscillatory periods; they also show the resonant effects associated with particular wave numbers.

Maria G. Romania; N. C. Tsamis; R. P. Woodard

2011-08-08T23:59:59.000Z

151

Kinematic dynamo induced by helical waves  

E-Print Network [OSTI]

We investigate numerically the kinematic dynamo induced by the superposition of two helical waves in a periodic box as a simplified model to understand the dynamo action in astronomical bodies. The effects of magnetic Reynolds number, wavenumber and wave frequency on the dynamo action are studied. It is found that this helical-wave dynamo is a slow dynamo. There exists an optimal wavenumber for the dynamo growth rate. A lower wave frequency facilitates the dynamo action and the oscillations of magnetic energy emerge at some particular wave frequencies.

Wei, Xing

2014-01-01T23:59:59.000Z

152

Seismic metamaterials based on isochronous mechanical oscillators  

SciTech Connect (OSTI)

This Letter introduces a seismic metamaterial (SM) composed by a chain of mass-in-mass system able to filter the S-waves of an earthquake. We included the effect of the SM into the mono dimensional model for the soil response analysis. The SM modifies the soil behavior and in presence of an internal damping the amplitude of the soil amplification function is reduced also in a region near the resonance frequency. This SM can be realized by a continuous structure with inside a 3d-matrix of isochronous oscillators based on a sphere rolling over a cycloidal trajectory.

Finocchio, G., E-mail: gfinocchio@unime.it; Garescì, F.; Azzerboni, B. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy); Casablanca, O.; Chiappini, M. [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Via Vigna Murata 605, 00143 Roma (Italy); Ricciardi, G. [Department of Civil, Informatic, Architectural, and Environmental Engineering and Applied Mathematics, C.da di Dio, I-98166 Messina (Italy); Alibrandi, U. [Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore)

2014-05-12T23:59:59.000Z

153

NOx Emission Reduction by Oscillating Combustion  

SciTech Connect (OSTI)

High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the attributes of oscillating combustion and on the results of an earlier project at GTI and Air Liquide, to determine which applications for oscillating combustion would show the greatest probability for technical success and greatest probability for market acceptability. The market study indicated that furnaces in the steel, glass, and metal melting industries would perform well in both categories. These findings guided the selection of burners for laboratory testing and, with the results of the laboratory testing, guided the selection of field test sites.

John C. Wagner

2004-03-31T23:59:59.000Z

154

NOx Emission Reduction by Oscillating combustion  

SciTech Connect (OSTI)

High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the attributes of oscillating combustion and on the results of an earlier project at GTI and Air Liquide, to determine which applications for oscillating combustion would show the greatest probability for technical success and greatest probability for market acceptability. The market study indicated that furnaces in the steel, glass, and metal melting industries would perform well in both categories. These findings guided the selection of burners for laboratory testing and, with the results of the laboratory testing, guided the selection of field test sites.

Institute of Gas Technology

2004-01-30T23:59:59.000Z

155

Damped quantum harmonic oscillator  

E-Print Network [OSTI]

In the framework of the Lindblad theory for open quantum systems the damping of the harmonic oscillator is studied. A generalization of the fundamental constraints on quantum mechanical diffusion coefficients which appear in the master equation for the damped quantum oscillator is presented; the Schr\\"odinger and Heisenberg representations of the Lindblad equation are given explicitly. On the basis of these representations it is shown that various master equations for the damped quantum oscillator used in the literature are particular cases of the Lindblad equation and that the majority of these equations are not satisfying the constraints on quantum mechanical diffusion coefficients. Analytical expressions for the first two moments of coordinate and momentum are also obtained by using the characteristic function of the Lindblad master equation. The master equation is transformed into Fokker-Planck equations for quasiprobability distributions. A comparative study is made for the Glauber $P$ representation, the antinormal ordering $Q$ representation and the Wigner $W$ representation. It is proven that the variances for the damped harmonic oscillator found with these representations are the same. By solving the Fokker-Planck equations in the steady state, it is shown that the quasiprobability distributions are two-dimensional Gaussians with widths determined by the diffusion coefficients. The density matrix is represented via a generating function, which is obtained by solving a time-dependent linear partial differential equation derived from the master equation. Illustrative examples for specific initial conditions of the density matrix are provided.

A. Isar; A. Sandulescu

2006-02-17T23:59:59.000Z

156

Wave VelocityWave Velocity Diff t f ti l l itDifferent from particle velocity  

E-Print Network [OSTI]

Wave VelocityWave Velocity v=/T =f Diff t f ti l l itDifferent from particle velocity Depends on the medium in which the wave travelsDepends on the medium in which the wave travels stringaonvelocity F v of Waves11-8. Types of Waves Transverse wave Longitudinal wave Liu UCD Phy1B 2014 37 #12;Sound Wave

Yoo, S. J. Ben

157

Oscillation-supported Information Processing  

E-Print Network [OSTI]

, intrinsic currents of neurons, dendritic Ca2+ spikes, and other voltage-dependent membrane oscillations7 Oscillation-supported Information Processing and Transfer at the HippocampusÀected by macroscopic oscillations. In each oscillatory cycle, recruitment of principal neurons is temporally protracted

Diba, Kamran

158

INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS  

E-Print Network [OSTI]

INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS Peter Kinget Bell Labs - Lucent Technologies Murray Hill, NJ (USA) Abstract The voltage controlled oscillator (VCO) is a critical sub. We focus on the de- sign of a critical sub-block: the voltage controlled oscillator (VCO). We review

Kinget, Peter

159

Cycloidal Wave Energy Converter  

SciTech Connect (OSTI)

This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

Stefan G. Siegel, Ph.D.

2012-11-30T23:59:59.000Z

160

Driven synchronization in random networks of oscillators  

E-Print Network [OSTI]

Synchronization is a universal phenomenon found in many non-equilibrium systems. Much recent interest in this area has overlapped with the study of complex networks, where a major focus is determining how a system's connectivity patterns affect the types of behavior that it can produce. Thus far, modeling efforts have focused on the tendency of networks of oscillators to mutually synchronize themselves, with less emphasis on the effects of external driving. In this work we discuss the interplay between mutual and driven synchronization in networks of phase oscillators of the Kuramoto type, and resolve how the structure and emergence of such states depends on the underlying network topology for simple random networks with a given degree distribution. We provide a partial bifurcation analysis, centering on the appearance of a Takens-Bogdanov-Cusp singularity, which broadly separates homogeneous and heterogeneous network behavior in a weak coupling limit, and from which the number, stability and appearance of dr...

Hindes, Jason

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

2011 Waves -1 STANDING WAVES  

E-Print Network [OSTI]

2011 Waves - 1 STANDING WAVES ON A STRING The objectives of the experiment are: · To show that standing waves can be set up on a string. · To determine the velocity of a standing wave. · To understand the differences between transverse and longitudinal waves. APPARATUS: Buzzer board with string, meter stick

Glashausser, Charles

162

I. Introduction A. Neutrino oscillation results from solar and atmospheric neutrino data.  

E-Print Network [OSTI]

V. This scenario is motivated in part by the need for an admixture (20{40%) of hot dark matter|roughly 7 eV worth oscillations in the matter of the Sun, and that the e and the neutrino type into which it oscillates, possibly and IMB imaging water Cherenkov detectors suggest that the observed disappearance of muon type neutrinos

McDonald, Kirk

163

WAVES OC514 Spring 2012 P.B. Rhines Term project ideas  

E-Print Network [OSTI]

WAVES OC514 Spring 2012 P.B. Rhines Term project ideas 10 Apr 2012 1. Coastal trapped waves signals, seasonal cycles, wind-driven signals 2. ENSO (el Nino/Southern Oscillation) and equatorial waves events? Atmospheric Kelvin and Rossby waves bridging from one ocean to the next. Gill model

164

Wave-particle duality and the Hamilton action  

E-Print Network [OSTI]

The Hamilton-Jacobi equation of relativistic quantum mechanics is revisited. The equation is shown to permit solutions in the form of breathers (oscillating/spinning solitons), displaying simultaneous particle-like and wave-like behaviour.

Gregory Sivashinsky

2009-09-23T23:59:59.000Z

165

Theoretical modelling of two wave-power devices  

E-Print Network [OSTI]

Many wave energy devices are currently studied. In this thesis we focus on two specific devices: the Oscillating Water Column (OWC), and the buoys. In the first part of this thesis we examine the effects of coastline ...

Lovas, Stéphanie

2010-01-01T23:59:59.000Z

166

arterial pulse wave: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cloning and trapping of magnetostatic spin-wave pulses by parametric pumping Kevin R. Smith,1 media,3 phase noise re- duction in crystal oscillators,4 theoretical production of...

167

aortic pulse wave: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cloning and trapping of magnetostatic spin-wave pulses by parametric pumping Kevin R. Smith,1 media,3 phase noise re- duction in crystal oscillators,4 theoretical production of...

168

Resonance energy transport in an oscillator chain  

E-Print Network [OSTI]

We investigate energy transfer and localization in a linear time-invariant oscillator chain weakly coupled to a forced nonlinear actuator. Two types of perturbation are studied: (1) harmonic forcing with a constant frequency is applied to the actuator (the Duffing oscillator) with slowly changing parameters; (2) harmonic forcing with a slowly increasing frequency is applied to the nonlinear actuator with constant parameters. In both cases, stiffness of linear oscillators as well as linear coupling remains constant, and the system is initially engaged in resonance. The parameters of the systems and forcing are chosen to guarantee autoresonance (AR) with gradually increasing energy in the nonlinear actuator. As this paper demonstrates, forcing with constant frequency generates oscillations with growing energy in the linear chain but in the system excited by forcing with slowly time-dependent frequency energy remains localized on the nonlinear actuator whilst the response of the linear chain is bounded. This means that the systems that seem to be almost identical exhibit different dynamical behavior caused by their different resonance properties. Numerical examples a good agreement between exact (numerical) solutions and their asymptotic approximations found by the multiple time scales method.

Agnessa Kovaleva

2015-01-03T23:59:59.000Z

169

LSND neutrino oscillation results  

SciTech Connect (OSTI)

The LSND (Liquid Scintillator Neutrino Detector) experiment at Los Alamos has conducted a search for muon antineutrino {r_arrow} electron antineutrino oscillations using muon neutrinos from antimuon decay at rest. The electron antineutrinos are detected via the reaction electron antineutrino + proton {r_arrow} positron + neutron, correlated with the 2.2-MeV gamma from neutron + proton {r_arrow} deuteron + gamma. The use of tight cuts to identify positron events with correlated gamma rays yields 22 events with positron energy between 36 and 60 MeV and only 4.6 {+-} 0.6 background events. The probability that this excess is due entirely to a statistical fluctuation is 4.1 {times} 10{sup -8}. A chi-squared fit to the entire positron sample results in a total excess of 51.8 {sup +18.7}{sub -16.9} {+-} 8.0 events with positron energy between 20 and 60 MeV. If attributed to muon antineutrino {r_arrow} electron antineutrino oscillations, this corresponds to an oscillation probability (averaged over the experimental energy and spatial acceptance) of (0.31 {+-} 0.12 {+-} 0.05){percent}. 10 refs., 7 figs., 1 tab.

Louis, W.C.; LSND Collaboration

1996-10-01T23:59:59.000Z

170

LSND neutrino oscillation results  

SciTech Connect (OSTI)

The LSND experiment at Los Alamos has conducted a search for {anti v}{sub {mu}} {yields} {anti v}{sub e} oscillations using {anti v}{sub {mu}} from {mu}{sup +} decay at rest. The {anti v}{sub e} are detected via the reaction {anti v}{sub e} p {yields} e{sup +}n, correlated with the 2.2 MeV {gamma} from n p {yields} d {gamma}. The use of tight cuts to identify e{sup +} events with correlated {gamma} rays yielded 22 events with e{sup +} energy between 36 and 60 MeV and only 4.6 {+-} 0.6 background events. The probability that this excess is due entirely to a statistical fluctuation is 4.1 {times} 10{sup {minus}8}. A {chi}{sup 2} fit to the entire e{sup +} sample results in a total excess of 51.8{sub {minus}16.9}{sup +18.7} {+-} 8.0 events with e{sup +} energy between 20 and 60 MeV. If attributed to {anti v}{sub {mu}} {yields} {anti v}{sub e} oscillations, this corresponds to an oscillation probability (averaged over the experimental energy and spatial acceptance) of 0.31 {+-} 0.12 {+-} 0.05%.

White, D.H.; LSND Collaboration

1997-11-01T23:59:59.000Z

171

Sensitivity of DANSS detector to short range neutrino oscillations  

E-Print Network [OSTI]

DANSS is a highly segmented $1m^3$ plastic scintillator detector. Its 2500 scintillator strips have a Gd loaded reflective cover. Light is collected with 3 wave length shifting fibers per strip and read out with 50 PMTs and 2500 SiPMs. The DANSS will be installed under the industrial 3GW$_{th}$ reactor of the Kalinin Nuclear Power Plant at distances varying from 9.7m to 12.2m from the reactor core. PMTs and SiPMs collect about 30 photo electrons per MeV distributed approximately equally between two types of the readout. Light collection non-uniformity across and along the strip is about $\\pm13\\%$ from maximum to minimum. The resulting energy resolution is modest, $\\sigma/E=15\\%$ at 5MeV. This leads to a smearing of the oscillation pattern comparable with the smearing due to the large size of the reactor core. Nevertheless because of the large counting rate ($\\sim 10000$ / day), small background ($Tests of the detector prototype DANSSino demonstrated that in spite of a small size ($4\\%$ of DANSS), it is quite sensitive to reactor antineutrinos, detecting about 70 Inverse Beta Decay events per day with the signal-to-background ratio of about unity. The prototype tests have demonstrated feasibility to reach the design performance of the DANSS detector.

Mikhail Danilov

2014-12-02T23:59:59.000Z

172

Sensitivity of DANSS detector to short range neutrino oscillations  

E-Print Network [OSTI]

DANSS is a highly segmented $1m^3$ plastic scintillator detector. Its 2500 scintillator strips have a Gd loaded reflective cover. Light is collected with 3 wave length shifting fibers per strip and read out with 50 PMTs and 2500 SiPMs. The DANSS will be installed under the industrial 3GW$_{th}$ reactor of the Kalinin Nuclear Power Plant at distances varying from 9.7m to 12.2m from the reactor core. PMTs and SiPMs collect about 30 photo electrons per MeV distributed approximately equally between two types of the readout. Light collection non-uniformity across and along the strip is about $\\pm13\\%$ from maximum to minimum. The resulting energy resolution is modest, $\\sigma/E=15\\%$ at 5MeV. This leads to a smearing of the oscillation pattern comparable with the smearing due to the large size of the reactor core. Nevertheless because of the large counting rate ($\\sim 10000$ / day), small background ($<1\\%$) and good control of systematic uncertainties due to frequent changes of positions, the DANSS is quite se...

Danilov, Mikhail

2014-01-01T23:59:59.000Z

173

hal-00283263,version1-29May2008 Submitted Nonlinear effects for coda-type elastic waves in stressed granular media  

E-Print Network [OSTI]

are presented on the nonlinear acoustic effects of multiple scattered elastic waves in unconsolidated granular modifications in the elastic response of an unconsolidated granular structure. PACS numbers: Valid PACS appear here I. INTRODUCTION Unconsolidated granular materials are known to ex- hibit a high complexity

Boyer, Edmond

174

Description of Stellar Acoustic Modes Using the Local Wave Concept  

E-Print Network [OSTI]

An understanding of stellar acoustic oscillations is attempted, using the local wave concept in semi-analytical calculations. The local homogeneity approximation allows to obtain simplified equations that can nevertheless describe the wave behavior down to the central region, as the gravitational potential perturbation is not neglected. Acoustic modes are calculated as classical standing waves in a cavity, by determining the cavity limits and the wave phases at these limits. The internal boundary condition is determined by a fitting with an Airy function. The external boundary condition is defined as the limit where the spatial variation of the background is important compared to the wavelength. This overall procedure is in accordance with the JWKB approximation. When comparing the results with numerical calculations, some drawbacks of the isothermal atmosphere approximation are revealed. When comparing with seismic observations of the Sun, possible improvements at the surface of solar models are suggested. The present semi-analytical method can potentially predict eigenfrequencies at the precision of +-3microHz in the range 800-5600 microHz, for the degrees l=0-10. A numerical calculation using the same type of external boundary conditions could reach a global agreement with observations better than 1 microHz. This approach could contribute to better determine the absolute values of eigenfrequencies for asteroseismology.

P. A. P. Nghiem

2006-06-26T23:59:59.000Z

175

Four cavity efficiency enhanced magnetically insulated line oscillator  

DOE Patents [OSTI]

A four cavity, efficient magnetically insulated line oscillator (C4-E MILO) having seven vanes and six cavities formed within a tube-like structure surrounding a cathode is disclosed. The C4-E MILO has a primary slow wave structure which is comprised of four vanes and the four cavities located near a microwave exit end of the tube-like structure. The primary slow wave structure is the four cavity portion of the magnetically insulated line oscillator (MILO). An RF choke is provided which is comprised of three of the vanes and two of the cavities. The RF choke is located near a pulsed power source portion of the tube-like structure surrounding the cathode. The RF choke increases feedback in the primary slow wave structure, prevents microwaves generated in the primary slow wave structure from propagating towards the pulsed power source and modifies downstream electron current so as to enhance microwave power generation. A beam dump/extractor is located at the exit end of the oscillator tube for extracting microwave power from the oscillator, and in conjunction with an RF extractor vane, which comprises the fourth vane of the primary slow wave structure (nearest the exit) having a larger gap radius than the other vanes of the primary SWS, comprises an RF extractor. Uninsulated electron flow is returned downstream towards the exit along an anode/beam dump region located between the beam dump/extractor and the exit where the RF is radiated at said RF extractor vane located near the exit and the uninsulated electron flow is disposed at the beam dump/extractor. 34 figs.

Lemke, R.W.; Clark, M.C.; Calico, S.E.

1998-04-21T23:59:59.000Z

176

Four cavity efficiency enhanced magnetically insulated line oscillator  

DOE Patents [OSTI]

A four cavity, efficient magnetically insulated line oscillator (C4-E MILO) having seven vanes and six cavities formed within a tube-like structure surrounding a cathode. The C4-E MILO has a primary slow wave structure which is comprised of four vanes and the four cavities located near a microwave exit end of the tube-like structure. The primary slow wave structure is the four cavity (C4) portion of the magnetically insulated line oscillator (MILO). An RF choke is provided which is comprised of three of the vanes and two of the cavities. The RF choke is located near a pulsed power source portion of the tube-like structure surrounding the cathode. The RF choke increases feedback in the primary slow wave structure, prevents microwaves generated in the primary slow wave structure from propagating towards the pulsed power source and modifies downstream electron current so as to enhance microwave power generation. A beam dump/extractor is located at the exit end of the oscillator tube for extracting microwave power from the oscillator, and in conjunction with an RF extractor vane, which comprises the fourth vane of the primary slow wave structure (nearest the exit) having a larger gap radius than the other vanes of the primary SWS, comprises an RF extractor. Uninsulated electron flow is returned downstream towards the exit along an anode/beam dump region located between the beam dump/extractor and the exit where the RF is radiated at said RF extractor vane located near the exit and the uninsulated electron flow is disposed at the beam dump/extractor.

Lemke, Raymond W. (Albuquerque, NM); Clark, Miles C. (Albuquerque, NM); Calico, Steve E. (Albuquerque, NM)

1998-04-21T23:59:59.000Z

177

Semiclassical wave-packets emerging from interaction with an environment  

SciTech Connect (OSTI)

We study the quantum evolution in dimension three of a system composed by a test particle interacting with an environment made of N harmonic oscillators. At time zero the test particle is described by a spherical wave, i.e., a highly correlated continuous superposition of states with well localized position and momentum, and the oscillators are in the ground state. Furthermore, we assume that the positions of the oscillators are not collinear with the center of the spherical wave. Under suitable assumptions on the physical parameters characterizing the model, we give an asymptotic expression of the solution of the Schrödinger equation of the system with an explicit control of the error. The result shows that the approximate expression of the wave function is the sum of two terms, orthogonal in L{sup 2}(R{sup 3(N+1)}) and describing rather different situations. In the first one, all the oscillators remain in their ground state and the test particle is described by the free evolution of a slightly deformed spherical wave. The second one consists of a sum of N terms where in each term there is only one excited oscillator and the test particle is correspondingly described by the free evolution of a wave packet, well concentrated in position and momentum. Moreover, the wave packet emerges from the excited oscillator with an average momentum parallel to the line joining the oscillator with the center of the initial spherical wave. Such wave packet represents a semiclassical state for the test particle, propagating along the corresponding classical trajectory. The main result of our analysis is to show how such a semiclassical state can be produced, starting from the original spherical wave, as a result of the interaction with the environment.

Recchia, Carla, E-mail: carla.recchia@libero.it [D.I.S.I.M., Università di L’Aquila, Via Vetoio - Loc. Coppito - 67010 L’Aquila (Italy)] [D.I.S.I.M., Università di L’Aquila, Via Vetoio - Loc. Coppito - 67010 L’Aquila (Italy); Teta, Alessandro, E-mail: teta@mat.uniroma1.it [Dipartimento di Matematica, “Sapienza” Università di Roma, P.le A. Moro 5, 00185 Roma (Italy)] [Dipartimento di Matematica, “Sapienza” Università di Roma, P.le A. Moro 5, 00185 Roma (Italy)

2014-01-15T23:59:59.000Z

178

Model wave functions and dynamic correlations in light-medium nuclei  

E-Print Network [OSTI]

The nuclei $^4$He, $^8$Be, $^{12}$C and $^{16}$O have been studied starting from nucleon-nucleon interactions of $v_4$ type. The wave function is built as the product of three terms, a Jastrow correlation factor, a linear correlation factor and a model wave function. The correlation factors account for both the short range repulsive and the spin and isospin dependence of the nuclear potential. The model wave function is antisymmetric and has the values of the angular momentum and parity of the state under description. For the model wave function we have used two different schemes. The first one is based on a Harmonic Oscillator shell model with and without deformation, and the second one is based on the Margenau-Brink model of alpha clustering. Projection operators of parity and total angular momentum are used. The performance of these two models is studied and compared systematically. Wave functions for the ground state and some members of its rotational band and some other bound states of these nuclei have been obtained. Binding energies, root mean square radius and the expectation value of the kinetic energy and the different channels of the nuclear interactions and the one-- and two-- body densities are reported. The two different model wave functions and the effects of the different nucleon-nucleon correlations have been evaluated on those quantities. All the results here presented have been obtained by using the Variational Monte Carlo method.

E Buendia; F J Galvez; J Praena; A Sarsa

2004-10-13T23:59:59.000Z

179

Gravitational waves from perturbed stars  

E-Print Network [OSTI]

Non radial oscillations of neutron stars are associated with the emission of gravitational waves. The characteristic frequencies of these oscillations can be computed using the theory of stellar perturbations, and they are shown to carry detailed information on the internal structure of the emitting source. Moreover, they appear to be encoded in various radiative processes, as for instance in the tail of the giant flares of Soft Gamma Repeaters. Thus, their determination is central to the theory of stellar perturbation. A viable approach to the problem consists in formulating this theory as a problem of resonant scattering of gravitational waves incident on the potential barrier generated by the spacetime curvature. This approach discloses some unexpected correspondences between the theory of stellar perturbations and the theory of quantum mechanics, and allows us to predict new relativistic effects.

Valeria Ferrari

2011-05-09T23:59:59.000Z

180

MSW Oscillations - LMA and Subdominant Effects  

E-Print Network [OSTI]

New physics near the TeV scale could modify neutrino-matter interactions or generate a relatively large neutrino magnetic (transition) moment. Both types of effects have been discussed since the 1970's as alternatives to mass-induced neutrino flavor oscillations. Nowadays, the availability of high-statistics data makes it possible to turn the idea around and ask: How well do the simple mass-induced oscillations describe solar neutrinos? At what level are the above-mentioned nonstandard effects excluded? Can we use solar neutrinos to constrain physics beyond the Standard Model? These notes review the sensitivity of the present-day solar neutrino experiments to the nonstandard neutrino interactions and transition moment and outline progress that may be expected in the near future. Based on a talk given at the Neutrino 2006 conference.

Friedland, A

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

NEUTRINO OSCILLATION RESULTS FROM LSND  

SciTech Connect (OSTI)

The Liquid Scintillator Neutrino Detector took data during the years 1993 through 1998. The results of a final analysis of the data are reported here. In summary, the analysis resulted in a cleaner sample of decay-at-rest oscillation candidates and provided a strong constraint on beam related backgrounds. The oscillation probability is fitted to the correlated photon parameter in the inclusive electron sample. The fit yields an excess of 83.3 {+-} 21.2 events attributable to neutrino oscillations. This corresponds to an oscillation probability of (0.25 {+-} 0.06 {+-} 0.04)% for that detector and beam configuration.

Mills, G.B.

2000-10-01T23:59:59.000Z

182

Gravitational Correction in Neutrino Oscillations  

E-Print Network [OSTI]

We investigate the quantum mechanical oscillations of neutrinos propagating in weak gravitational field. The correction to the result in the flat space-time is derived.

Yasufumi Kojima

1996-12-17T23:59:59.000Z

183

Feedback Induced Death in Coupled Oscillators  

E-Print Network [OSTI]

We investigate oscillation death in systems of coupled nonlinear oscillators with feedback loop. We find that feedback results in oscillation death both in small sets or large ensembles. More importantly, the death zone in parameter space is significantly enlarged and oscillation death could occur even in coupled identical oscillators in the presence of feedback. We find that there are two different ways to oscillation death, namely desynchronization and completely synchronization induced oscillation death. Feedback induced oscillation death may be used to suppress unexpected oscillations, e.g., in chaotic laser arrays.

Ming Luo

2011-11-10T23:59:59.000Z

184

Collective oscillations in spatially modulated exciton-polariton condensate arrays  

E-Print Network [OSTI]

We study collective dynamics of interacting centers of exciton-polariton condensation in presence of spatial inhomogeneity, as modeled by diatomic active oscillator lattices. The mode formalism is developed and employed to derive existence and stability criteria of plane wave solutions. It is demonstrated that $k_0=0$ wave number mode with the binary elementary cell on a diatomic lattice possesses superior existence and stability properties. Decreasing net on-site losses (balance of dissipation and pumping) or conservative nonlinearity favors multistability of modes, while increasing frequency mismatch between adjacent oscillators detriments it. On the other hand, spatial inhomogeneity may recover stability of modes at high nonlinearities. Entering the region where all single-mode solutions are unstable we discover subsequent transitions between localized quasiperiodic, chaotic and global chaotic dynamics in the mode space, as nonlinearity increases. Importantly, the last transition evokes the loss of synchronization. These effects may determine lasing dynamics of interacting exciton-polariton condensation centers.

A. A. Tikhomirov; O. I. Kanakov; B. L. Altshuler; M. V. Ivanchenko

2014-07-25T23:59:59.000Z

185

Multi-rhythmicity in an optoelectronic oscillator with large delay  

E-Print Network [OSTI]

An optoelectronic oscillator exhibiting a large delay in its feedback loop is studied both experimentally and theoretically. We show that multiple square-wave oscillations may coexist for the same values of the parameters (multi-rhythmicity). Depending on the sign of the phase shift, these regimes admit either periods close to an integer fraction of the delay or periods close to an odd integer fraction of twice the delay. These periodic solutions emerge from successive Hopf bifurcation points and stabilize at a finite amplitude following a scenario similar to Eckhaus instability in spatially extended systems. We find quantitative agreements between experiments and numerical simulations. The linear stability of the square-waves is substantiated analytically by determining stable fixed points of a map.

Weicker, Lionel; Rosin, David P; Gauthier, Daniel J

2014-01-01T23:59:59.000Z

186

Dirac bound states of anharmonic oscillator in external fields  

SciTech Connect (OSTI)

We explore the effect of the external magnetic and Aharonov–Bohm (AB) flux fields on the energy levels of Dirac particle subjects to mixed scalar and vector anharmonic oscillator field in the two-dimensional (2D) space. We calculate the exact energy eigenvalues and the corresponding un-normalized two-spinor-components wave functions in terms of the chemical potential parameter, magnetic field strength, AB flux field and magnetic quantum number by using the Nikiforov–Uvarov (NU) method. -- Highlights: • Effect of the external fields on the energy levels of Dirac particle with the anharmonic oscillator is investigated. • The solutions are discussed in view of spin and pseudospin symmetries limits. • The energy levels and wave function are presented by the Nikiforov–Uvarov method.

Hamzavi, Majid, E-mail: majid.hamzavi@gmail.com [Department of Physics, University of Zanjan, Zanjan (Iran, Islamic Republic of)] [Department of Physics, University of Zanjan, Zanjan (Iran, Islamic Republic of); Ikhdair, Sameer M., E-mail: sikhdair@gmail.com [Department of Physics, Faculty of Science, an-Najah National University, Nablus, West Bank, Palestine (Country Unknown); Department of Electrical and Electronic Engineering, Near East University, 922022 Nicosia, Northern Cyprus, Mersin 10 (Turkey); Falaye, Babatunde J., E-mail: fbjames11@physicist.net [Theoretical Physics Section, Department of Physics, University of Ilorin, P. M. B. 1515, Ilorin (Nigeria)

2014-02-15T23:59:59.000Z

187

Nanoscale relaxation oscillator  

DOE Patents [OSTI]

A nanoscale oscillation device is disclosed, wherein two nanoscale droplets are altered in size by mass transport, then contact each other and merge through surface tension. The device may also comprise a channel having an actuator responsive to mechanical oscillation caused by expansion and contraction of the droplets. It further has a structure for delivering atoms between droplets, wherein the droplets are nanoparticles. Provided are a first particle and a second particle on the channel member, both being made of a chargeable material, the second particle contacting the actuator portion; and electrodes connected to the channel member for delivering a potential gradient across the channel and traversing the first and second particles. The particles are spaced apart a specified distance so that atoms from one particle are delivered to the other particle by mass transport in response to the potential (e.g. voltage potential) and the first and second particles are liquid and touch at a predetermined point of growth, thereby causing merging of the second particle into the first particle by surface tension forces and reverse movement of the actuator. In a preferred embodiment, the channel comprises a carbon nanotube and the droplets comprise metal nanoparticles, e.g. indium, which is readily made liquid.

Zettl, Alexander K. (Kensington, CA); Regan, Brian C. (Los Angeles, CA); Aloni, Shaul (Albany, CA)

2009-04-07T23:59:59.000Z

188

On the harmonic oscillator realisation of q-oscillators  

E-Print Network [OSTI]

The general version of the bosonic harmonic oscillator realisation of bosonic q-oscillators is given. It is shown that the currently known realisation is a special case of our general solution. The investigation has been performed at the Laboratory of theoretical Physics,JINR.

D. Gangopadhyay; A. P. Isaev

2007-01-05T23:59:59.000Z

189

Dirac bound states of anharmonic oscillator in external fields  

E-Print Network [OSTI]

We explore the effect of the external magnetic and Aharonov-Bohm (AB) flux fields on the energy levels of Dirac particle subjects to mixed scalar and vector anharmonic oscillator field in the two-dimensional (2D) space. We calculate the exact energy eigenvalues and the corresponding un-normalized two-spinor-components wave functions in terms of the chemical potential parameter, magnetic field strength, AB flux field and magnetic quantum number by using the Nikiforov-Uvarov (NU) method.

Majid Hamzavia; Sameer M. Ikhdair; Babatunde J. Falaye

2014-01-28T23:59:59.000Z

190

Harmonic oscillator in a background magnetic field in noncommutative quantum phase-space  

E-Print Network [OSTI]

We solve explicitly the two-dimensional harmonic oscillator and the harmonic oscillator in a background magnetic field in noncommutative phase-space without making use of any type of representation. A key observation that we make is that for a specific choice of the noncommutative parameters, the time reversal symmetry of the systems get restored since the energy spectrum becomes degenerate. This is in contrast to the noncommutative configuration space where the time reversal symmetry of the harmonic oscillator is always broken.

Joseph Ben Geloun; Sunandan Gangopadhyay; Frederik G Scholtz

2009-01-22T23:59:59.000Z

191

Neutrino Oscillations Experiments at Fermilab  

E-Print Network [OSTI]

Neutrino oscillations provide an unique opportunity to probe physics beyond the Standard Model. Fermilab is constructing two new neutrino beams to provide a decicive test of two of the recent positive indications for neutrino oscillations: MiniBOONE experiment will settle the LSND controversy, MINOS will provide detailed studies of the region indicated by the SuperK results.

Adam Para

2000-05-01T23:59:59.000Z

192

Non-expanding impulsive gravitational waves  

E-Print Network [OSTI]

We investigate a class of impulsive gravitational waves which propagate either in Minkowski or in the (anti-)de Sitter background. These waves are constructed as impulsive members of the Kundt class $P(\\Lambda)$ of non-twisting, non-expanding type N solutions of vacuum Einstein equations with a cosmological constant $\\Lambda$. We show that the only non-trivial waves of this type in Minkowski spacetime are impulsive pp-waves. For $\\Lambda\

J. Podolsky

1998-07-29T23:59:59.000Z

193

Wave dynamics in a sunspot umbra  

E-Print Network [OSTI]

The high spatial and time resolution data obtained with SDO/AIA for the sunspot in active region NOAA 11131 on 08 December 2010 were analysed with the time-distance plot technique and the pixelised wavelet filtering method. Oscillations in the 3 min band dominate in the umbra. The integrated spectrum of umbral oscillations contains distinct narrowband peaks at 1.9 min, 2.3 min, and 2.8 min. The power significantly varies in time, forming distinct oscillation trains. The oscillation power distribution over the sunspot in the horizontal plane reveals that the enhancements of the oscillation amplitude, or wave fronts, have a distinct structure consisting of an evolving two-armed spiral and a stationary circular patch at the spiral origin, situated near the umbra centre. This structure is seen from the temperature minimum to the corona. In time, the spiral rotates anti-clockwise. The wave front spirality is most pronounced during the maximum amplitude phases of the oscillations. In the low-amplitude phases the sp...

Sych, R

2014-01-01T23:59:59.000Z

194

Constraints on oscillating dark energy models  

E-Print Network [OSTI]

The oscillating scenario of route to Lambda was recently proposed by us arXiv:0704.1651 as an alternative to a cosmological constant in a explanation of the current accelerating universe. In this scenario phantom scalar field conformally coupled to gravity drives the accelerating phase of the universe. In our model $\\Lambda$CDM appears as a global attractor in the phase space. In this paper we investigate observational constraints on this scenario from recent measurements of distant supernovae type Ia, CMB R shift, BAO and $H(z)$ observational data. The Bayesian methods of model selection are used in comparison the model with concordance $\\Lambda$CDM one as well as with model with dynamical dark energy parametrised by linear form. We conclude that $\\Lambda$CDM is favoured over FRW model with dynamical oscillating dark energy. Our analysis also demonstrate that FRW model with oscillating dark energy is favoured over FRW model with decaying dark energy parametrised in linear way.

Aleksandra Kurek; Orest Hrycyna; Marek Szydlowski

2007-11-23T23:59:59.000Z

195

Systematic expansion for infrared oscillator basis extrapolations  

E-Print Network [OSTI]

Recent work has demonstrated that the infrared effects of harmonic oscillator basis truncations are well approximated by imposing a partial-wave Dirichlet boundary condition at a properly identified radius L. This led to formulas for extrapolating the corresponding energy E_L and other observables to infinite L and thus infinite basis size. Here we reconsider the energy for a two-body system with a Dirichlet boundary condition at L to identify and test a consistent and systematic expansion for E_L that depends only on observables. We also generalize the energy extrapolation formula to nonzero angular momentum, and apply it to the deuteron. Formulas given previously for extrapolating the radius are derived in detail.

R. J. Furnstahl; S. N. More; T. Papenbrock

2014-03-20T23:59:59.000Z

196

Breaking waves: Bifurcations leading to a singular wave state W. Tao Shi, Christopher L. Goodridge, and Daniel P. Lathrop*  

E-Print Network [OSTI]

, modulated, and frequency locked wave states lead to a state with fluid spikes. When the excitation of free- quency of 7.4 Hz to excite a (2,2) Fourier mode. A highly viscous liquid is chosen here to dampen high region and the corner areas of the liquid surface oscillate out of phase. Large amplitude waves couple

Lathrop, Daniel P.

197

Particle acceleration in superluminal strong waves  

E-Print Network [OSTI]

We calculate the electron acceleration in random superluminal strong waves (SLSWs) and radiation from them by using numerical methods in the context of the termination shock of the pulsar wind nebulae. We pursue the electrons by solving the equation of motion in the analytically expressed electromagnetic turbulences. These consist of primary SLSW and isotropically distributed secondary electromagnetic waves. Under the dominance of the secondary waves, all electrons gain nearly equal energy. On the other hand, when the primary wave is dominant, selective acceleration occurs. The phase of the primary wave felt by the electrons moving nearly along the wavevector changes very slowly compared to the oscillation of the wave, which is called "phase locked", and such electrons are continuously accelerated. This acceleration by SLSWs may play a crucial role in the pre-acceleration for the shock acceleration. In general, the radiation from the phase-locked population is different from the synchro-Compton radiation. How...

Teraki, Yuto; Nagataki, Shigehiro

2015-01-01T23:59:59.000Z

198

Cosmological bounds on oscillating dark energy models  

E-Print Network [OSTI]

We study some cosmological constraints on the two phenomenological models of oscillating dark energy. In these scenarios, the equation of state of dark energy varies periodically and may provide a way to unify the early acceleration (inflation) and the late time acceleration of the universe. These models give also an effective way to tackle the so-called cosmic coincidence problem. We examine observational constraints on this class of models from the latest observational data including the \\emph{gold} sample of 182 type Ia supernovae, the CMB shift parameter $R$ and the BAO measurements from the Sloan Digital Sky Survey.

Deepak Jain; Abha Dev; J. S. Alcaniz

2007-09-26T23:59:59.000Z

199

Coulomb Oscillations in Antidots in the Integer and Fractional Quantum Hall Regimes  

E-Print Network [OSTI]

We report measurements of resistance oscillations in micron-scale antidots in both the integer and fractional quantum Hall regimes. In the integer regime, we conclude that oscillations are of the Coulomb type from the scaling of magnetic field period with the number of edges bound to the antidot. Based on both gate-voltage and field periods, we find at filling factor {\

A. Kou; C. M. Marcus; L. N. Pfeiffer; K. W. West

2012-01-08T23:59:59.000Z

200

Coulomb Oscillations in Antidots in the Integer and Fractional Quantum Hall Regimes  

E-Print Network [OSTI]

We report measurements of resistance oscillations in micron-scale antidots in both the integer and fractional quantum Hall regimes. In the integer regime, we conclude that oscillations are of the Coulomb type from the scaling of magnetic field period with the number of edges bound to the antidot. Based on both gate-voltage and field periods, we find at filling factor {\

Kou, A; Pfeiffer, L N; West, K W

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Lead-position dependent regular oscillations and random fluctuations of conductance in graphene quantum dots  

E-Print Network [OSTI]

Lead-position dependent regular oscillations and random fluctuations of conductance in graphene.1088/0953-8984/25/8/085502 Lead-position dependent regular oscillations and random fluctuations of conductance in graphene quantum, for graphene quantum dots, the conductance variations with the lead positions. Since for graphene the types

Lai, Ying-Cheng

202

Method to improve optical parametric oscillator beam quality  

DOE Patents [OSTI]

A method to improving optical parametric oscillator (OPO) beam quality having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

Smith, Arlee V.; Alford, William J.; Bowers, Mark S.

2003-11-11T23:59:59.000Z

203

MSW Effects in Vacuum Oscillations  

E-Print Network [OSTI]

We point out that for solar neutrino oscillations with the mass-squared difference of Delta m^2 ~ 10^-10 - 10^-9 eV^2, traditionally known as ``vacuum oscillation'' range, the solar matter effects are non-negligible, particularly for the low energy pp neutrinos. One consequence of this is that the values of the mixing angle theta and pi/2-theta are not equivalent, leading to the need to consider the entire physical range of the mixing angle 0<=theta<=pi/2 when determining the allowed values of the neutrino oscillation parameters.

Alexander Friedland

2000-05-18T23:59:59.000Z

204

Equal energy phase space trajectories in resonant wave interactions O. Yaakobia  

E-Print Network [OSTI]

Equal energy phase space trajectories in resonant wave interactions O. Yaakobia and L. Friedlandb interacting wave systems with nonlinear frequency/ wave vector shifts is discussed. The corresponding these parameters vary in time or space. It is shown that the oscillation periods of two equal energy trajectories

Friedland, Lazar

205

Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1  

E-Print Network [OSTI]

Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1 J. Liang,1 E aurora ­ the longitudinally propagating arc wave (LPAW) ­ associated with flapping oscillations, and K. H. Glassmeier (2009), Longitudinally propagating arc wave in the pre-onset optical aurora

California at Berkeley, University of

206

Review Article Propagating waves in thalamus, cortex and the thalamocortical system  

E-Print Network [OSTI]

Review Article Propagating waves in thalamus, cortex and the thalamocortical system: Experiments-sensitive dye Multi-electrode array Population dynamics Propagating waves Oscillations Sensory cortices Spiking neural networks a b s t r a c t Propagating waves of activity have been recorded in many species

Destexhe, Alain

207

The saddle-node of nearly homogeneous wave trains in reaction-diffusion systems  

E-Print Network [OSTI]

The saddle-node of nearly homogeneous wave trains in reaction-diffusion systems Jens D homogeneous oscillations created in the bifurcation, we investigate existence and stability of wave trains trains and determine their stability on the unbounded real line. We confirm that the accompanying wave

Scheel, Arnd

208

Wave-Particle Duality and the Hamilton-Jacobi Equation  

E-Print Network [OSTI]

The Hamilton-Jacobi equation of relativistic quantum mechanics is revisited. The equation is shown to permit solutions in the form of breathers (oscillating/spinning solitons), displaying simultaneous particle-like and wave-like behavior. The de Broglie wave thus acquires a clear deterministic meaning of a wave-like excitation of the classical action function. The problem of quantization in terms of the breathing action function and the double-slit experiment are discussed.

Gregory I. Sivashinsky

2009-12-28T23:59:59.000Z

209

Transient voltage oscillations in coils  

SciTech Connect (OSTI)

Magnet coils may be excited into internal voltage oscillations by transient voltages. Such oscillations may electrically stress the magnet's dielectric components to many times its normal stress. This may precipitate a dielectric failure, and the attendant prolonged loss of service and costly repair work. Therefore, it is important to know the natural frequencies of oscillations of a magnet during the design stage, and to determine whether the expected switching transient voltages can excite the magnet into high-voltage internal oscillations. The series capacitance of a winding significantly affects its natural frequencies. However, the series capacitance is difficult to calculate, because it may comprise complex capacitance network, consisting of intra- and inter-coil turn-to-turn capacitances of the coil sections. A method of calculating the series capacitance of a winding is proposed. This method is rigorous but simple to execute. The time-varying transient voltages along the winding are also calculated.

Chowdhuri, P.

1985-01-01T23:59:59.000Z

210

Cluster Dynamics of Planetary Waves  

E-Print Network [OSTI]

The dynamics of nonlinear atmospheric planetary waves is determined by a small number of independent wave clusters consisting of a few connected resonant triads. We classified the different types of connections between neighboring triads that determine the general dynamics of a cluster. Each connection type corresponds to substantially different scenarios of energy flux among the modes. The general approach can be applied directly to various mesoscopic systems with 3-mode interactions, encountered in hydrodynamics, astronomy, plasma physics, chemistry, medicine, etc.

Elena Kartashova; Victor S. L'vov

2008-11-05T23:59:59.000Z

211

Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

0.13 Step-up transformer 14,844 1 15 989.61 0.07 Mechanical Components Motor-to-generator coupling 278 1 20 13.92 0.05 Hingeflap bearings 6,549 2 20 654.89 0.05...

212

Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

For extreme sea states, we assumed the RM5 design was not operating, that the flap was locked at 45 degrees, and that the structure was subject to 20% inflated 100-year extreme...

213

Method of Focussing Waves by Inhomogeneous Oscillations of the underlying  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergyInnovation Portal Biomass andFor PuttingMedium |

214

Analysis, modeling and simulation of ring resonators and their applications to filters and oscillators  

E-Print Network [OSTI]

with good agreement. This simple equivalent circuit model provides a useful method to design and understand this type of filters and other relative circuits.Finally, a tunable feedback ring resonator oscillator using a voltage controlled piezoelectric...

Hsieh, Lung-Hwa

2004-09-30T23:59:59.000Z

215

Oscillations of a Magnetized Plasma in a Waveguide of Complicated Shape  

SciTech Connect (OSTI)

Potential hybrid oscillations in a resonator of arbitrary shape are investigated theoretically. It is shown that, for a periodic waveguide, the frequency dependence of the wavenumber is represented by a fractal curve of the 'devil's staircase' type.

Ignatov, A. M. [Russian Academy of Sciences, Institute of General Physics (Russian Federation)] [Russian Academy of Sciences, Institute of General Physics (Russian Federation)

2002-07-15T23:59:59.000Z

216

Geometric gravitational origin of neutrino oscillations and mass-energy  

E-Print Network [OSTI]

A mass-energy scale for neutrinos was calculated from the null cone curvature using geometric concepts. The scale is variable depending on the gravitational potential and the trajectory inclination with respect to the field direction. The proposed neutrino covariant equation provides the adequate curvature. The mass-energy at the Earth surface varies from a horizontal value 0.402 eV to a vertical value 0.569 eV. Earth spinor waves with winding numbers n show squared energy differences within ranges from 2.05 x 10*(-3) to 4.10 x 10*(-3) eV*2 for n=0,1 neutrinos and from 3.89 x 10*(-5) to 7.79 x 10*(-5) eV*2 for n=1,2 neutrinos. These waves interfere and the different phase velocities produce neutrino-like oscillations. The experimental results for atmospheric and solar neutrino oscillation mass parameters respectivelly fall within these theoretical ranges. Neutrinos in outer space, where interactions may be neglected, appear as particles travelling with zero mass on null geodesics. These gravitational curvature energies are consistent with neutrino oscillations, zero neutrino rest masses and Einstein's General Relativity and energy mass equivalence principle. When analyzing or averaging experimental neutrino mass-energy results of different experiments on the Earth it is of interest to consider the possible influence of the trajectory inclination angle.

Gustavo R. Gonzalez-Martin

2014-05-21T23:59:59.000Z

217

Solar cell as self-oscillating heat engine  

E-Print Network [OSTI]

Solar cells are engines converting energy supplied by the photon flux into work. Any type of engine is also a self-oscillating system which yields a periodic motion at the expense of a usually non-periodic source of energy. This aspect is absent in the existing descriptions and the main goal of this paper is to show that plasma oscillations provide this necessary ingredient of work extraction process. Our approach is based on Markovian master equations which can be derived in a rigorous way from the underlying Hamiltonian models and are consistent with the laws of thermodynamics.

Robert Alicki; David Gelbwaser-Klimovsky; Krzysztof Szczygielski

2015-01-04T23:59:59.000Z

218

Intermittent and sustained periodic windows in networked chaotic Rössler oscillators  

SciTech Connect (OSTI)

Route to chaos (or periodicity) in dynamical systems is one of fundamental problems. Here, dynamical behaviors of coupled chaotic Rössler oscillators on complex networks are investigated and two different types of periodic windows with the variation of coupling strength are found. Under a moderate coupling, the periodic window is intermittent, and the attractors within the window extremely sensitively depend on the initial conditions, coupling parameter, and topology of the network. Therefore, after adding or removing one edge of network, the periodic attractor can be destroyed and substituted by a chaotic one, or vice versa. In contrast, under an extremely weak coupling, another type of periodic window appears, which insensitively depends on the initial conditions, coupling parameter, and network. It is sustained and unchanged for different types of network structure. It is also found that the phase differences of the oscillators are almost discrete and randomly distributed except that directly linked oscillators more likely have different phases. These dynamical behaviors have also been generally observed in other networked chaotic oscillators.

He, Zhiwei; Sun, Yong [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China) [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhan, Meng, E-mail: zhanmeng@wipm.ac.cn [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)] [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

2013-12-15T23:59:59.000Z

219

THE SOURCE OF 3 MINUTE MAGNETOACOUSTIC OSCILLATIONS IN CORONAL FANS  

SciTech Connect (OSTI)

We use images of high spatial, spectral, and temporal resolution, obtained using both ground- and space-based instrumentation, to investigate the coupling between wave phenomena observed at numerous heights in the solar atmosphere. Analysis of 4170 A continuum images reveals small-scale umbral intensity enhancements, with diameters {approx}0.''6, lasting in excess of 30 minutes. Intensity oscillations of Almost-Equal-To 3 minutes are observed to encompass these photospheric structures, with power at least three orders of magnitude higher than the surrounding umbra. Simultaneous chromospheric velocity and intensity time series reveal an 87 Degree-Sign {+-} 8 Degree-Sign out-of-phase behavior, implying the presence of standing modes created as a result of partial wave reflection at the transition region boundary. We find a maximum waveguide inclination angle of Almost-Equal-To 40 Degree-Sign between photospheric and chromospheric heights, combined with a radial expansion factor of <76%. An average blueshifted Doppler velocity of Almost-Equal-To 1.5 km s{sup -1}, in addition to a time lag between photospheric and chromospheric oscillatory phenomena, confirms the presence of upwardly propagating slow-mode waves in the lower solar atmosphere. Propagating oscillations in EUV intensity are detected in simultaneous coronal fan structures, with a periodicity of 172 {+-} 17 s and a propagation velocity of 45 {+-} 7 km s{sup -1}. Numerical simulations reveal that the damping of the magnetoacoustic wave trains is dominated by thermal conduction. The coronal fans are seen to anchor into the photosphere in locations where large-amplitude umbral dot (UD) oscillations manifest. Derived kinetic temperature and emission measure time series display prominent out-of-phase characteristics, and when combined with the previously established sub-sonic wave speeds, we conclude that the observed EUV waves are the coronal counterparts of the upwardly propagating magnetoacoustic slow modes detected in the lower solar atmosphere. Thus, for the first time, we reveal how the propagation of 3 minute magnetoacoustic waves in solar coronal structures is a direct result of amplitude enhancements occurring in photospheric UDs.

Jess, D. B.; Mathioudakis, M.; Reardon, K. P.; Keys, P. H.; Keenan, F. P. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); De Moortel, I. [School of Mathematics and Statistics, University of St Andrews, St Andrews KY16 9SS (United Kingdom); Christian, D. J., E-mail: d.jess@qub.ac.uk [Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330 (United States)

2012-10-01T23:59:59.000Z

220

Vacuum Waves  

E-Print Network [OSTI]

As an example of the unification of gravitation and particle physics, an exact solution of the five-dimensional field equations is studied which describes waves in the classical Einstein vacuum. While the solution is essentially 5D in nature, the waves exist in ordinary 3D space, and may provide a way to test for an extra dimension.

Paul S. Wesson

2012-12-11T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Design of a terahertz parametric oscillator based on a resonant cavity in a terahertz waveguide  

SciTech Connect (OSTI)

We demonstrate ns-pulsed pumping of terahertz (THz) parametric oscillations in a quasi-triply resonant cavity in a THz waveguide. The THz waves, down converted through parametric interactions between the pump and signal waves at telecom frequencies, are confined to a GaP single mode ridge waveguide. By combining the THz waveguide with a quasi-triply resonant cavity, the nonlinear interactions can be enhanced. A low threshold pump intensity for parametric oscillations can be achieved in the cavity waveguide. The THz output power can be maximized by optimizing the quality factors of the cavity so that an optical to THz photon conversion efficiency, ?{sub p}, of 0.35, which is near the quantum-limit level, can be attained. The proposed THz optical parametric oscillator can be utilized as an efficient and monochromatic THz source.

Saito, K., E-mail: k-saito@material.tohoku.ac.jp; Oyama, Y. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-11-1021, Aoba-ku, 980-8579 Sendai (Japan); Tanabe, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, 980-8577 Sendai (Japan)

2014-07-28T23:59:59.000Z

222

Oscillation-induced sand ripples in a circular geometry Germain Rousseaux*  

E-Print Network [OSTI]

by surface water waves at the fluid-granular interface on the beach. Historically, the first laboratory ex d relative density with respect to water s/ f =2.49 . Then we fill the tank with water kinematic oscillating cir- cular tanks filled with water, at the bottom of which they put a layer of sand 1,2 . More

Wesfreid, José Eduardo

223

Power loss of an oscillating electric dipole in a quantum plasma  

SciTech Connect (OSTI)

A system of linearized quantum plasma equations (quantum hydrodynamic model) has been used for investigating the dispersion equation for electrostatic waves in the plasma. Furthermore, dispersion relations and their modifications due to quantum effects are used for calculating the power loss of an oscillating electric dipole. Finally, the results are compared in quantum and classical regimes.

Ghaderipoor, L. [Department of Physics, Faculty of Science, University of Qom, 3716146611 (Iran, Islamic Republic of); Mehramiz, A. [Department of Physics, Faculty of Science, Imam Khomeini Int'l University, Qazvin 34149-16818 (Iran, Islamic Republic of)

2012-12-15T23:59:59.000Z

224

Search for gravitational waves associated with the August 2006 timing glitch of the Vela pulsar  

E-Print Network [OSTI]

The physical mechanisms responsible for pulsar timing glitches are thought to excite quasinormal mode oscillations in their parent neutron star that couple to gravitational-wave emission. In August 2006, a timing glitch ...

Barsotti, Lisa

225

Dynamics of intracellular Ca$^{2+}$ oscillations in the presence of multisite Ca$^{2+}$-binding proteins  

E-Print Network [OSTI]

We study the dynamics of intracellular calcium oscillations in the presence of proteins that bind calcium on multiple sites and that are generally believed to act as passive calcium buffers in cells. We find that multisite calcium-binding proteins set a sharp threshold for calcium oscillations. Even with high concentrations of calcium-binding proteins, internal noise, which shows up spontaneously in cells in the process of calcium wave formation, can lead to self-oscillations. This produces oscillatory behaviors strikingly similar to those observed in real cells. In addition, for given intracellular concentrations of both calcium and calcium-binding proteins the regularity of these oscillations changes and reaches a maximum as a function noise variance, and the overall system dynamics displays stochastic coherence. We conclude that calcium-binding proteins may have an important and active role in cellular communication.

Roberto Chignola; Alessio Del Fabbro; Edoardo Milotti

2009-09-10T23:59:59.000Z

226

Plasma waves reflection from a boundary with specular accommodative boundary conditions  

E-Print Network [OSTI]

In the present work the linearized problem of plasma wave reflection from a boundary of a half--space is solved analytically. Specular accommodative conditions of plasma wave reflection from plasma boundary are taken into consideration. Wave reflectance is found as function of the given parameters of the problem, and its dependence on the normal electron momentum accommodation coefficient is shown by the authors. The case of resonance when the frequency of self-consistent electric field oscillations is close to the proper (Langmuir) plasma oscillations frequency, namely, the case of long wave limit is analyzed. Refs. 17. Figs. 6.

N. V. Gritsienko; A. V. Latyshev; A. A. Yushkanov

2010-01-06T23:59:59.000Z

227

Inflation With Oscillations  

E-Print Network [OSTI]

In this paper we investigate the general features of "Oscillatory Inflation". In adiabatic approximation, we derive a general formula for the number of e-foldings $\\tilde{N}$ which reduces to the standard expression in case of the slow role approximation and leads to the Damour-Mukhanov type expression for the slowly varying adiabatic index. We apply our result to the logarithmic potential and arrive at a simple and elegant formula for the number of e-foldings. We evolve the field equations numerically and observe a remarkable agreement with the analytical result.

M. Sami

2001-06-23T23:59:59.000Z

228

Clustered Chimera States in Systems of Type-I Excitability  

E-Print Network [OSTI]

Chimera is a fascinating phenomenon of coexisting synchronized and desynchronized behaviour that was discovered in networks of nonlocally coupled identical phase oscillators over ten years ago. Since then, chimeras were found in numerous theoretical and experimental studies and more recently in models of neuronal dynamics as well. In this work, we consider a generic model for a saddle-node bifurcation on a limit cycle representative for neural excitability type I. We obtain chimera states with multiple coherent regions (clustered chimeras/multi-chimeras) depending on the distance from the excitability threshold, the range of nonlocal coupling as well as the coupling strength. A detailed stability diagram for these chimera states as well as other interesting coexisting patterns like traveling waves are presented.

Andrea Vüllings; Johanne Hizanidis; Iryna Omelchenko; Philipp Hövel

2014-07-20T23:59:59.000Z

229

Evidence for Solar-like Oscillations in Arcturus (Alpha Boo)  

E-Print Network [OSTI]

Observations of the red giant Arcturus (Alpha Boo) obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a baseline of 19 successive days in 2000 July-August are analysed. The power spectrum has a significant excess of power at low-frequencies. The highest peak is at about 4.1 micro-Hz, which is in agreement with the ground-based radial velocity and photometry study of Belmonte et al. (1990a; 1990b). The variability of Arcturus can be explained by sound waves, but it is not clear whether these are coherent p-mode oscillations.

Alon Retter; Timothy R. Bedding; Derek Buzasi; Hans Kjeldsen

2002-08-28T23:59:59.000Z

230

Chapter 10: Waves Did you read chapter 10  

E-Print Network [OSTI]

Properties: Speed The speed of sound is 340 m/s (about 1/5 mile/sec) The speed of light is 3x108 m/s You unchanged Speed = frequency Ã? wavelength. Sound "Talking" Outboard Propeller whine A compression wave Compression waves can travel through solids and fluids Solid Liquid Gas #12;2 Types of Waves: Transverse waves

Hart, Gus

231

POINTWISE GREEN FUNCTION BOUNDS AND STABILITY OF COMBUSTION WAVES  

E-Print Network [OSTI]

POINTWISE GREEN FUNCTION BOUNDS AND STABILITY OF COMBUSTION WAVES GREGORY LYNG, MOHAMMADREZA ROOFI for traveling wave solutions of an abstract viscous combustion model including both Majda's model and the full-wave) approximation. Notably, our results apply to combustion waves of any type: weak or strong, detonations or defla

Texier, Benjamin - Institut de Mathématiques de Jussieu, Université Paris 7

232

MATHEMATICAL ANALYSIS OF A WAVE ENERGY CONVERTER ARNAUD ROUGIREL  

E-Print Network [OSTI]

for buoy-type ocean wave energy converter. The simplest model for this scheme is a non autonomous piecewise impact on the environment. In this respect, ocean waves provides a important source of renewable energy. Me- chanical devices that harvest energy stored in ocean waves are called wave energy converter (WEC

Paris-Sud XI, Université de

233

Resonant Generation of Internal Waves on a Model Continental Slope H. P. Zhang, B. King, and Harry L. Swinney  

E-Print Network [OSTI]

Resonant Generation of Internal Waves on a Model Continental Slope H. P. Zhang, B. King, and Harry wave generation in a laboratory model of oscillating tidal flow on a continental margin. Waves are found to be generated only in a near-critical region where the slope of the bottom topography matches

Texas at Austin. University of

234

Single mode pulsed dye laser oscillator  

DOE Patents [OSTI]

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability.

Hackel, Richard P. (Livermore, CA)

1992-01-01T23:59:59.000Z

235

Single mode pulsed dye laser oscillator  

DOE Patents [OSTI]

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability. 6 figs.

Hackel, R.P.

1992-11-24T23:59:59.000Z

236

Lepton textures and neutrino oscillations  

E-Print Network [OSTI]

Systematic analyses of the textures arising in lepton mass matrices have been carried out using unitary transformations and condition of naturalness for the Dirac and Majorana neutrino possibilities. It is observed that the recent three neutrino oscillation data together with the effective mass in neutrinoless double beta decay provide vital clues in predicting the general structures of these lepton mass matrices.

Verma, Rohit

2014-01-01T23:59:59.000Z

237

Wave represents displacement Wave represents pressure Source -Sound Waves  

E-Print Network [OSTI]

Wave represents displacement Wave represents pressure Source - Sound Waves Distance between crests is wavelength Number of crests passing a point in 1 second is frequency Wave represents pressure Target - Radio Waves Distance between crests is wavelength Number of crests passing a point in 1 second is frequency

Colorado at Boulder, University of

238

Fractional Electromagnetic Waves  

E-Print Network [OSTI]

In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía

2011-08-31T23:59:59.000Z

239

Free-Oscillations Coincident with Earthquakes  

E-Print Network [OSTI]

Two de-modulation algorithms are used to observe free-oscillations of the earth that are coincident with earthquakes.

Randall D. Peters

2010-10-27T23:59:59.000Z

240

Do the Kamiokande results need neutrino oscillations?  

E-Print Network [OSTI]

Neutrino oscillations are a delicate and important subject. One needs to be sure that every aspect of it is well understood. The recent results of the Kamiokande experiment [1], indicate the possibility of -- neutrino oscillations. The period of oscillation observed by Kamiokande is not compatible with what one may deduce from the solar neutrino experiments [2]. In this letter, we examine if another mechanism could fake neutrino oscillations and could be measurement dependent

Baillon, Paul

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Silicon crystal growing by oscillating crucible technique  

DOE Patents [OSTI]

A process for growing silicon crystals from a molten melt comprising oscillating the container during crystal growth is disclosed.

Schwuttke, G.H.; Kim, K.M.; Smetana, P.

1983-08-03T23:59:59.000Z

242

Oscillator or Segal-Shale-Weil representation Geometry: Associating the oscillator to symplectic manifolds  

E-Print Network [OSTI]

C -algebras Oscillator or Segal-Shale-Weil representation Geometry: Associating the oscillator or Segal-Shale-Weil representation Geometry: Associating the oscillator to symplectic manifolds Global and (x) = 0 implies x = 0 2 S. Krýsl #12;C -algebras Oscillator or Segal-Shale-Weil representation

Krysl, Svatopluk

243

Comparison between Gaussian-type orbitals and plane wave ab initio density functional theory modeling of layer silicates: Talc [Mg{sub 3}Si{sub 4}O{sub 10}(OH){sub 2}] as model system  

SciTech Connect (OSTI)

The quantum chemical characterization of solid state systems is conducted with many different approaches, among which the adoption of periodic boundary conditions to deal with three-dimensional infinite condensed systems. This method, coupled to the Density Functional Theory (DFT), has been proved successful in simulating a huge variety of solids. Only in relatively recent years this ab initio quantum-mechanic approach has been used for the investigation of layer silicate structures and minerals. In the present work, a systematic comparison of different DFT functionals (GGA-PBEsol and hybrid B3LYP) and basis sets (plane waves and all-electron Gaussian-type orbitals) on the geometry, energy, and phonon properties of a model layer silicate, talc [Mg{sub 3}Si{sub 4}O{sub 10}(OH){sub 2}], is presented. Long range dispersion is taken into account by DFT+D method. Results are in agreement with experimental data reported in literature, with minimal deviation given by the GTO/B3LYP-D* method regarding both axial lattice parameters and interaction energy and by PW/PBE-D for the unit-cell volume and angular values. All the considered methods adequately describe the experimental talc infrared spectrum.

Ulian, Gianfranco; Valdrè, Giovanni, E-mail: giovanni.valdre@unibo.it [Dipartimento di Scienze Biologiche e Geologico-Ambientali, Centro di Ricerca Interdisciplinare di Biomineralogia, Cristallografia e Biomateriali, Università di Bologna “Alma Mater Studiorum” Piazza di Porta San Donato 1, 40126 Bologna (Italy)] [Dipartimento di Scienze Biologiche e Geologico-Ambientali, Centro di Ricerca Interdisciplinare di Biomineralogia, Cristallografia e Biomateriali, Università di Bologna “Alma Mater Studiorum” Piazza di Porta San Donato 1, 40126 Bologna (Italy); Tosoni, Sergio [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)] [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)

2013-11-28T23:59:59.000Z

244

Radiation reaction and quantum damped harmonic oscillator  

E-Print Network [OSTI]

By taking a Klein-Gordon field as the environment of an harmonic oscillator and using a new method for dealing with quantum dissipative systems (minimal coupling method), the quantum dynamics and radiation reaction for a quantum damped harmonic oscillator investigated. Applying perturbation method, some transition probabilities indicating the way energy flows between oscillator, reservoir and quantum vacuum, obtained

F. Kheirandish; M. Amooshahi

2005-07-19T23:59:59.000Z

245

14 Modelling Ca2+ Oscillations in Plants  

E-Print Network [OSTI]

14 Modelling Ca2+ Oscillations in Plants GERALD SCHÃ?NKNECHT*1 AND CLAUDIA BAUER2 Abstract To interpret the physiological functions of Ca2+ oscillations in plants cells, one has to understand how Ca2 predict how a certain stimulus might affect the frequency or amplitude of a Ca2+ oscillation. Usually

Schönknecht, Gerald

246

The Quantum Harmonic Oscillator C. David Sherrill  

E-Print Network [OSTI]

The Quantum Harmonic Oscillator C. David Sherrill School of Chemistry and Biochemistry Georgia Institute of Technology February 2002 1 Introduction The harmonic oscillator is extremely useful by coupled harmonic oscillators. The atoms are viewed as point masses which are connected by bonds which act

Sherrill, David

247

Possible Enhancement of High Frequency Gravitational Waves  

E-Print Network [OSTI]

We study the tensor perturbations in a class of non-local, purely gravitational models which naturally end inflation in a distinctive phase of oscillations with slight and short violations of the weak energy condition. We find the usual generic form for the tensor power spectrum. The presence of the oscillatory phase leads to an enhancement of gravitational waves with frequencies somewhat less than 10^{10} Hz.

Maria G. Romania; N. C. Tsamis; R. P. Woodard

2011-03-05T23:59:59.000Z

248

Acoustic waves in random ensembles of magnetic fluxes  

SciTech Connect (OSTI)

To analyze the observational data and provide the appropriate diagnostic procedure for photospheric manifestation of solar oscillations it is necessary to take into account strong inhomogeneity of solar atmosphere with respect to distribution of magnetic fields. We study the collective phenomena in the propagation of acoustic waves and unsteady wave-packets through quite regions, sunspots and plages, including time-dependent response of these regions to solar oscillations, the energy transfer mechanisms, frequency shift effects and reradiation of the acoustic waves in higher layers of atmosphere. We show that the dynamics of differently magnetized regions, their dispersion properties, and their response to the propagation of acoustic waves are completely different. We describe the effects caused by the specific distribution and randomness of magnetic flux tubes, which can be observed and which can provide the tools for diagnostic goals.

Ryutova, M.P.

1995-10-10T23:59:59.000Z

249

Measuring neutrino oscillation parameters using $\  

SciTech Connect (OSTI)

MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the 'atmospheric' neutrino oscillation parameters ({Delta}m{sub atm}{sup 2} and sin{sup 2} 2{theta}{sub atm}). The oscillation signal consists of an energy-dependent deficit of {nu}{sub {mu}} interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the {nu}{sub {mu}}-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the {nu}{sub {mu}}-disappearance analysis, incorporating this new estimator were: {Delta}m{sup 2} = 2.32{sub -0.08}{sup +0.12} x 10{sup -3} eV{sup 2}, sin {sup 2} 2{theta} > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly {bar {nu}}{sub {mu}} beam, yielded somewhat different best-fit parameters {Delta}{bar m}{sup 2} = (3.36{sub -0.40}{sup +0.46}(stat.) {+-} 0.06(syst.)) x 10{sup -3}eV{sup 2}, sin{sup 2} 2{bar {theta}} = 0.86{sub -0.12}{sup _0.11}(stat.) {+-} 0.01(syst.). The tension between these results is intriguing, and additional antineutrino data is currently being taken in order to further investigate this apparent discrepancy.

Backhouse, Christopher James; /Oxford U.

2011-02-01T23:59:59.000Z

250

Rogue waves for a long wave-short wave resonance model with multiple short waves  

E-Print Network [OSTI]

1 Rogue waves for a long wave-short wave resonance model with multiple short waves Hiu Ning Chan (1 waves; Long-short resonance PACS Classification: 02.30.Jr; 05.45.Yv; 47.35.Fg #12;2 ABSTRACT A resonance between long and short waves will occur if the phase velocity of the long wave matches the group velocity

251

Combustor oscillating pressure stabilization and method  

DOE Patents [OSTI]

High dynamic pressure oscillations in hydrocarbon-fueled combustors typically occur when the transport time of the fuel to the flame front is at some fraction of the acoustic period. These oscillations are reduced to acceptably lower levels by restructuring or repositioning the flame front in the combustor to increase the transport time. A pilot flame front located upstream of the oscillating flame and pulsed at a selected frequency and duration effectively restructures and repositions the oscillating flame in the combustor to alter the oscillation-causing transport time.

Gemmen, Randall S. (Morgantown, WV); Richards, George A. (Morgantown, WV); Yip, Mui-Tong Joseph (Morgantown, WV); Robey, Edward H. (Westover, WV); Cully, Scott R. (Morgantown, WV); Addis, Richard E. (Smithfield, PA)

1998-01-01T23:59:59.000Z

252

The MSW effect and Matter Effects in Neutrino Oscillations  

E-Print Network [OSTI]

The MSW (Mikheyev-Smirnov-Wolfenstein) effect is the adiabatic or partially adiabatic neutrino flavor conversion in medium with varying density. The main notions related to the effect, its dynamics and physical picture are reviewed. The large mixing MSW effect is realized inside the Sun providing the solution of the solar neutrino problem. The small mixing MSW effect driven by the 1-3 mixing can be realized for the supernova (SN) neutrinos. Inside the collapsing stars new elements of the MSW dynamics may show up: the non-oscillatory transition, non-adiabatic conversion, time dependent adiabaticity violation induced by shock waves. Effects of the resonance enhancement and the parametric enhancement of oscillations can be realized for the atmospheric and accelerator neutrinos in the Earth. Precise results for neutrino oscillations in the low density medium with arbitrary density profile are presented and the attenuation effect is described. The area of applications is the solar and SN neutrinos inside the Earth, and the results are crucial for the neutrino oscillation tomography.

A. Yu. Smirnov

2004-12-27T23:59:59.000Z

253

Ion beam oscillation due to fluctuation of a hot filament driven magnetized plasma  

SciTech Connect (OSTI)

Ion beam current extracted from a modified Bernas type ion source occasionally exhibits an oscillation at a frequency of several 100 kHz. Increase in the strength of a linear magnetic field induced to the ion source has either decreased or increased the frequency of this oscillation. The frequency showed an increase in proportion to the ion extraction voltage when the frequency decreased with increasing magnetic field. The change of extraction voltage did not affect the frequency when the frequency increased with the increasing magnetic field. Mechanisms causing these oscillations of an ion beam had been investigated.

Imakita, S.; Kasuya, T.; Kimura, Y.; Wada, M. [Graduate School of Engineering, Doshisha University, Kyoto 610-0321 (Japan); Miyamoto, N. [Nissin Ion Equipment Co. Ltd., Kyoto 601-8205 (Japan)

2010-02-15T23:59:59.000Z

254

Quantum dynamics of the damped harmonic oscillator  

E-Print Network [OSTI]

The quantum theory of the damped harmonic oscillator has been a subject of continual investigation since the 1930s. The obstacle to quantization created by the dissipation of energy is usually dealt with by including a discrete set of additional harmonic oscillators as a reservoir. But a discrete reservoir cannot directly yield dynamics such as Ohmic damping (proportional to velocity) of the oscillator of interest. By using a continuum of oscillators as a reservoir, we canonically quantize the harmonic oscillator with Ohmic damping and also with general damping behaviour. The dynamics of a damped oscillator is determined by an arbitrary effective susceptibility that obeys Kramers-Kronig relations. This approach offers an alternative description of nano-mechanical oscillators and opto-mechanical systems.

Philbin, T G

2012-01-01T23:59:59.000Z

255

Quantum dynamics of the damped harmonic oscillator  

E-Print Network [OSTI]

The quantum theory of the damped harmonic oscillator has been a subject of continual investigation since the 1930s. The obstacle to quantization created by the dissipation of energy is usually dealt with by including a discrete set of additional harmonic oscillators as a reservoir. But a discrete reservoir cannot directly yield dynamics such as Ohmic damping (proportional to velocity) of the oscillator of interest. By using a continuum of oscillators as a reservoir, we canonically quantize the harmonic oscillator with Ohmic damping and also with general damping behaviour. The dynamics of a damped oscillator is determined by an arbitrary effective susceptibility that obeys Kramers-Kronig relations. This approach offers an alternative description of nano-mechanical oscillators and opto-mechanical systems.

T. G. Philbin

2012-05-11T23:59:59.000Z

256

Oscillators: Old and new perspectives  

SciTech Connect (OSTI)

We consider some of the well known oscillators in literature which are known to exhibit interesting effects of nonlinearity. We review the Lindstedt-Poincare technique for dealing with with the nonlinear effects and then go on to introduce the relevance of the renormalization group for the oscillator following the pioneering work of Chen et al. It is pointed out that the traditional Lindstedt-Poincare and the renormalization group techniques have operational connections. We use this to find an unexpected mode softening in the double pendulum. This mode softening prompted us to look for chaos in the double pendulum at low energies-energies that are just sufficient to allow the outer pendulum to rotate (the double pendulum is known to be chaotic at high energies-energies that are greater than that needed to make both pendulums to rotate). The emergence of the chaos is strongly dependent on initial conditions.

Bhattacharjee, Jayanta K. [Harish-Chandra Research Institute, Jhunsi, Allahabad 211019 (India); Roy, Jyotirmoy [UM-DAE Centre for Excellence in Basic Sciences, Santa Cruz(E), Mumbai 400098 (India)

2014-02-11T23:59:59.000Z

257

Vortices in Brain waves  

E-Print Network [OSTI]

2003). Vortices in Brain Waves 62. M. E. Raichle, ScienceVORTICES IN BRAIN WAVES WALTER J. FREEMAN Department ofthat is recorded in brain waves (electroencephalogram, EEG).

Freeman, Walter J III; Vitiello, Giuseppe

2010-01-01T23:59:59.000Z

258

Graphene, neutrino mass and oscillation  

E-Print Network [OSTI]

A resolution of the Abraham-Minkowski dilemma is presented that other constant velocities can play the role of c in the theory of relativity. For example, in 2005 electrons of graphene were discovered to behave as if the coefficient is a Fermi velocity. Then we propose a conjecture for neutrinos to avoid the contradiction among two-component theory, negative rest mass-square and oscillation.

Z. Y. Wang

2011-03-28T23:59:59.000Z

259

Micro-machined resonator oscillator  

DOE Patents [OSTI]

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a telemetered sensor beacon'' that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20--100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available. 21 figs.

Koehler, D.R.; Sniegowski, J.J.; Bivens, H.M.; Wessendorf, K.O.

1994-08-16T23:59:59.000Z

260

Micro-machined resonator oscillator  

DOE Patents [OSTI]

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

Koehler, Dale R. (Albuquerque, NM); Sniegowski, Jeffry J. (Albuquerque, NM); Bivens, Hugh M. (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM)

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Inhomogeneous High Frequency Expansion-Free Gravitational Waves  

E-Print Network [OSTI]

We describe a natural inhomogeneous generalization of high frequency plane gravitational waves. The waves are high frequency waves of the Kundt type whose null propagation direction in space-time has vanishing expansion, twist and shear but is not covariantly constant. The introduction of a cosmological constant is discussed in some detail and a comparison is made with high frequency gravity waves having wave fronts homeomorphic to 2-spheres.

C. Barrabes; P. A. Hogan

2007-06-18T23:59:59.000Z

262

Impurity bands and quasi-Bloch waves for a one-dimensional model of modulated crystal  

E-Print Network [OSTI]

from the theory of quasi-periodic functions while the second relies on periodicity properties, impurity band, quasi-Bloch wave, quantum chaos, spectral algorithm, deformed crystal, Charge-Density Wave coupled oscillators; consult the book [1] and the recent paper [14] to which we are about to borrow

Paris-Sud XI, Université de

263

Electronic and optical properties of single excitons and biexcitons in type-II quantum dot nanocrystals  

SciTech Connect (OSTI)

In this study, a detailed investigation of the electronic and optical properties (i.e., binding energies, absorption wavelength, overlap of the electron-hole wave functions, recombination oscillator strength, etc.) of an exciton and a biexciton in CdTe/CdSe core/shell type-II quantum dot heterostructures has been carried out in the frame of the single band effective mass approximation. In order to determine the electronic properties, we have self-consistently solved the Poisson-Schrödinger equations in the Hartree approximation. We have considered all probable Coulomb interaction effects on both energy levels and also on the corresponding wave functions for both single exciton and biexciton. In addition, we have taken into account the quantum mechanical exchange-correlation effects in the local density approximation between same kinds of particles for biexciton. Also, we have examined the effect of the ligands and dielectric mismatch on the electronic and optical properties. We have used a different approximation proposed by Sahin and Koc [Appl. Phys. Lett. 102, 183103 (2013)] for the recombination oscillator strength of the biexciton for bound and unbound cases. The results obtained have been presented comparatively as a function of the shell thicknesses and probable physical reasons in behind of the results have been discussed in a detail.

Koc, Fatih, E-mail: fatih.koc@msn.com [Department of Physics, Faculty of Sciences, Selcuk University, 42075 Konya (Turkey); Sahin, Mehmet, E-mail: mehmet.sahin@agu.edu.tr, E-mail: mehsahin@gmail.com [Department of Physics, Faculty of Sciences, Selcuk University, 42075 Konya (Turkey); Department of Material Science and Nanotechnology Engineering, Abdullah Gül University, Kayseri (Turkey)

2014-05-21T23:59:59.000Z

264

A Characterization of the Brightness Oscillations During Thermonuclear Bursts From 4U 1636-536  

E-Print Network [OSTI]

The discovery of nearly coherent brightness oscillations during thermonuclear X-ray bursts from six neutron-star low-mass X-ray binaries has opened up a new way to study the propagation of thermonuclear burning, and may ultimately lead to greater understanding of thermonuclear propagation in other astrophysical contexts, such as in Type Ia supernovae. Here we report detailed analyses of the ~580 Hz brightness oscillations during bursts from 4U 1636-536. We investigate the bursts as a whole and, in more detail, the initial portions of the bursts. We analyze the ~580 Hz oscillations in the initial 0.75 seconds of the five bursts that were used in a previous search for a brightness oscillation at the expected ~290 Hz spin frequency, and find that if the same frequency model describes all five bursts there is insufficient data to require more than a constant frequency or, possibly, a frequency plus a frequency derivative. Therefore, although it is appropriate to use an arbitrarily complicated model of the ~580 Hz oscillations to generate a candidate waveform for the ~290 Hz oscillations, models with more than two parameters are not required by the data. For the bursts as a whole we show that the characteristics of the brightness oscillations vary greatly from burst to burst. We find, however, that in at least one of the bursts, and possibly in three of the four that have strong brightness oscillations throughout the burst, the oscillation frequency reaches a maximum several seconds into the burst and then decreases. This behavior has not been reported previously for burst brightness oscillations, and it poses a challenge to the standard burning layer expansion explanation for the frequency changes.

M. Coleman Miller

1999-04-08T23:59:59.000Z

265

Autoresonant Dynamics of Optical Guided Waves Assaf Barak,1  

E-Print Network [OSTI]

. Autoresonance offers a different way to maintain phase locking even when the system is excited deeply phase locking and amplification to predetermined amplitudes. This constitutes the first observation resonance, remaining phase locked with driving oscillations (or waves) despite variations in the system

Friedland, Lazar

266

Photon Plasma-Wave Interaction via Compton Scattering  

E-Print Network [OSTI]

The Kompaneets theory of photon kinetic evolution due to the Compton effect is extended to the case of the Vlasov plasma wave oscillations. Taking into account Zel'dovich-Levich's approximation we study interaction of accumulating photons with plasma in the long wavelength limit.

Galina Erochenkova; Cristel Chandre

2012-08-16T23:59:59.000Z

267

Wave Control Introduction  

E-Print Network [OSTI]

the Oscillating Water Column (OWC) device with wind turbine a new device with a more direct energy conversion? #12

Wirosoetisno, Djoko

268

Nonlinear Hysteretic Torsional Waves  

E-Print Network [OSTI]

We theoretically study and experimentally report the propagation of nonlinear hysteretic torsional pulses in a vertical granular chain made of cm-scale, self-hanged magnetic beads. As predicted by contact mechanics, the torsional coupling between two beads is found nonlinear hysteretic. This results in a nonlinear pulse distortion essentially different from the distortion predicted by classical nonlinearities, and in a complex dynamic response depending on the history of the wave particle angular velocity. Both are consistent with the predictions of purely hysteretic nonlinear elasticity and the Preisach-Mayergoyz hysteresis model, providing the opportunity to study the phenomenon of nonlinear dynamic hysteresis in the absence of other type of material nonlinearities. The proposed configuration reveals a plethora of interesting phenomena including giant amplitude-dependent attenuation, short term memory as well as dispersive properties. Thus, it could find interesting applications in nonlinear wave control devices such as strong amplitude-dependent filters.

J. Cabaret; P. Béquin; G. Theocharis; V. Andreev; V. E. Gusev; V. Tournat

2015-01-09T23:59:59.000Z

269

Nonlinear Hysteretic Torsional Waves  

E-Print Network [OSTI]

We theoretically study and experimentally report the propagation of nonlinear hysteretic torsional pulses in a vertical granular chain made of cm-scale, self-hanged magnetic beads. As predicted by contact mechanics, the torsional coupling between two beads is found nonlinear hysteretic. This results in a nonlinear pulse distortion essentially different from the distortion predicted by classical nonlinearities, and in a complex dynamic response depending on the history of the wave particle angular velocity. Both are consistent with the predictions of purely hysteretic nonlinear elasticity and the Preisach-Mayergoyz hysteresis model, providing the opportunity to study the phenomenon of nonlinear dynamic hysteresis in the absence of other type of material nonlinearities. The proposed configuration reveals a plethora of interesting phenomena including giant amplitude-dependent attenuation, short term memory as well as dispersive properties. Thus, it could find interesting applications in nonlinear wave control de...

Cabaret, J; Theocharis, G; Andreev, V; Gusev, V E; Tournat, V

2015-01-01T23:59:59.000Z

270

Shock Wave Impact on Weak Concrete , K.D. Gardner1  

E-Print Network [OSTI]

. The major effect of a terrorist-type bomb is from the blast, particularly from blast wave reflection when. This paper reports on the use of a shock wave to simulate the effect of a blast wave on weak concrete. A high/19, Moscow, Russia Abstract. A blast wave front possesses characteristics similar to a shock wave created

Texas at Arlington, University of

271

Transition from amplitude to oscillation death in a network of oscillators  

E-Print Network [OSTI]

We report a transition from a homogeneous steady state (HSS) to inhomogeneous steady states (IHSSs) in a network of globally coupled identical oscillators. We perturb a synchronized population in the network with a few local negative mean field links. It is observed that the whole population splits into two clusters for a certain number of negative mean field links and specific range of coupling strength. For further increases of the strength of interaction these clusters collapse to a HSS followed by a transition to IHSSs. We analytically determine the origin of HSS and its transition to IHSS in relation to the number of negative mean-field links and the strength of interaction using a reductionism approach to the model network in a two-cluster state. We verify the results with numerical examples of networks using the paradigmatic Landau-Stuart limit cycle system and the chaotic Rossler oscillator as dynamical nodes. During the transition from HSS to IHSSs, the network follows the Turing type symmetry breaking pitchfork or transcritical bifurcation depending upon the system dynamics.

Mauparna Nandan; C. R. Hens; Pinaki Pal; Syamal K. Dana

2014-09-29T23:59:59.000Z

272

Oscillations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics Group (X-rayLSD Logo AboutSignatureStatus: Design,

273

Neutrino oscillation studies at LAMPF  

SciTech Connect (OSTI)

A search for {anti v}{sub {mu}} {yields} {anti v}{sub e} oscillations has been made by the Liquid Scintillator Neutrino Detector experiment at LAMPF after an initial month and a half run. The experiment observes eight events consistent with the reaction {anti v}{sub e}p {yields} e{sup +}n followed by np {yields} d{gamma} (2.2 MeV). The total estimated background is 0.9{plus_minus}0.2 events.

Louis, W.C.; LSND Collaboration

1994-09-01T23:59:59.000Z

274

Neutrino Oscillation Studies with Reactors  

E-Print Network [OSTI]

Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

Petr Vogel; Liangjian Wen; Chao Zhang

2015-03-03T23:59:59.000Z

275

Neutrino Oscillation Studies with Reactors  

E-Print Network [OSTI]

Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

Vogel, Petr; Zhang, Chao

2015-01-01T23:59:59.000Z

276

N=2 supersymmetric Pais-Uhlenbeck oscillator  

E-Print Network [OSTI]

We construct an N=2 supersymmetric extension of the Pais-Uhlenbeck oscillator for distinct frequencies of oscillation. A link to a set of decoupled N=2 supersymmetric harmonic oscillators with alternating sign in the Hamiltonian is introduced. Symmetries of the model are discussed in detail. The investigation of a quantum counterpart of the constructed model shows that the corresponding Fock space contains negative norm states and the energy spectrum of the system is unbounded from below.

Ivan Masterov

2015-03-12T23:59:59.000Z

277

Peaks and Troughs in Helioseismology: The Power Spectrum of Solar Oscillations  

E-Print Network [OSTI]

I present a matched-wave asymptotic analysis of the driving of solar oscillations by a general localised source. The analysis provides a simple mathematical description of the asymmetric peaks in the power spectrum in terms of the relative locations of eigenmodes and troughs in the spectral response. It is suggested that the difference in measured phase function between the modes and the troughs in the spectrum will provide a key diagnostic of the source of the oscillations. I also suggest a form for the asymmetric line profiles to be used in the fitting of solar power spectra. Finally I present a comparison between the numerical and asymptotic descriptions of the oscillations. The numerical results bear out the qualitative features suggested by the asymptotic analysis but suggest that numerical calculations of the locations of the troughs will be necessary for a quantitative comparison with the observations.

Colin S. Rosenthal

1998-04-03T23:59:59.000Z

278

On the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation: Might they be related?  

E-Print Network [OSTI]

? Marc d'Orgeville1 and W. Richard Peltier1 Received 3 August 2007; revised 21 September 2007; accepted 1. Peltier (2007), On the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation: Might

Peltier, W. Richard

279

Non-standard Neutrino Oscillations at Icecube  

E-Print Network [OSTI]

In this talk I review the potential of Icecube for revealing physics beyond the standard model in the oscillation of atmospheric neutrinos.

M. C. Gonzalez-Garcia

2006-12-19T23:59:59.000Z

280

Interfacing ultracold atoms and mechanical oscillators.  

E-Print Network [OSTI]

??In this thesis I present experiments investigating controlled coupling between mechanical oscillators and ultracold atoms. I report on three different coupling mechanisms. In a first… (more)

Camerer, Stephan

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Droop-Controlled Inverters are Kuramoto Oscillators  

E-Print Network [OSTI]

Droop-Controlled Inverters are Kuramoto Oscillators John W. Simpson-Porco Florian D¨orfler Barbara, Santa Barbara, CA 93106, USA, (e-mail: {johnwsimpsonporco,dorfler

Bullo, Francesco

282

High frequency and high wavenumber solar oscillations  

E-Print Network [OSTI]

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\

H. M. Antia; Sarbani Basu

1999-02-10T23:59:59.000Z

283

Nonlinear nanomechanical oscillators for ultrasensitive inertial detection  

DOE Patents [OSTI]

A system for ultrasensitive mass and/or force detection of this invention includes a mechanical oscillator driven to oscillate in a nonlinear regime. The mechanical oscillator includes a piezoelectric base with at least one cantilever resonator etched into the piezoelectric base. The cantilever resonator is preferably a nonlinear resonator which is driven to oscillate with a frequency and an amplitude. The system of this invention detects an amplitude collapse of the cantilever resonator at a bifurcation frequency as the cantilever resonator stimulated over a frequency range. As mass and/or force is introduced to the cantilever resonator, the bifurcation frequency shifts along a frequency axis in proportion to the added mass.

Datskos, Panagiotis George; Lavrik, Nickolay V

2013-08-13T23:59:59.000Z

284

Markovian evolution of strongly coupled harmonic oscillators  

E-Print Network [OSTI]

We investigate how to model Markovian evolution of coupled harmonic oscillators, each of them interacting with a local environment. When the coupling between the oscillators is weak, dissipation may be modeled using local Lindblad terms for each of the oscillators in the master equation, as is commonly done. When the coupling between oscillators is strong, this model may become invalid. We derive a master equation for two coupled harmonic oscillators which are subject to individual heat baths modeled by a collection of harmonic oscillators, and show that this master equation in general contains non-local Lindblad terms. We compare the resulting time evolution with that obtained for dissipation through local Lindblad terms for each individual oscillator, and show that the evolution is different in the two cases. In particular, the two descriptions give different predictions for the steady state and for the entanglement between strongly coupled oscillators. This shows that when describing strongly coupled harmonic oscillators, one must take great care in how dissipation is modeled, and that a description using local Lindblad terms may fail. This may be particularly relevant when attempting to generate entangled states of strongly coupled quantum systems.

Chaitanya Joshi; Patrik Ohberg; James D. Cresser; Erika Andersson

2014-12-16T23:59:59.000Z

285

Coda wave interferometry 1 Coda wave interferometry  

E-Print Network [OSTI]

Coda wave interferometry 1 Coda wave interferometry An interferometer is an instrument that is sensitive to the interference of two or more waves (optical or acoustic). For example, an optical interferometer uses two interfering light beams to measure small length changes. Coda wave interferometry

Snieder, Roel

286

Micromagnetic study of auto-oscillation modes in spin-Hall nano-oscillators  

SciTech Connect (OSTI)

We present a numerical study of magnetization dynamics in a recently introduced spin torque nano-oscillator, whose operational principle relies on the spin-Hall effect—spin-Hall nano-oscillators. Our numerical results show good agreement with the experimentally observed behaviors and provide detailed information about the features of the primary auto-oscillation mode observed in the experiments. They also clarify the physical nature of the secondary auto-oscillation mode, which was experimentally observed under certain conditions only.

Ulrichs, H., E-mail: henning.ulrichs@uni-muenster.de; Demidov, V. E.; Demokritov, S. O. [Department of Physics and Center for Nonlinear Science, University of Münster, Corrensstraße 2-4, 48149 Münster (Germany)

2014-01-27T23:59:59.000Z

287

Remarks on the formation and decay of multidimensional shock waves  

E-Print Network [OSTI]

In this paper, we present a formula describing the formation and decay of shock wave type solutions in some special cases.

V. G. Danilov

2005-12-27T23:59:59.000Z

288

Dynamics of two populations of phase oscillators with different frequency distributions  

E-Print Network [OSTI]

A large variety of rhythms have been observed in nature. These rhythms can be often regarded to interact with each other, such as electroencephalogram (EEG) in the brain. To investigate the dynamical properties of such systems, in this paper, we consider two populations of phase oscillators with different frequency distributions, particularly under the condition that the average frequency of fast oscillators is almost equal to the integral multiple of that of slow oscillators. What is the most important point is that we have to use the specific type of the coupling function derived from the phase reduction theory. Under some additional assumption, moreover, we can reduce the system consisting of two populations of coupled phase oscillators to a low-dimensional system in the continuum limit. As a result, we find chimera states in which clustering and incoherent states coexist. We also confirm that the behaviors of the derived low-dimensional model fairly agree with that of the original one.

Yu Terada; Toshio Aoyagi

2014-11-19T23:59:59.000Z

289

The light mutant oscillator (LMO); a novel circadian oscillator in Neurospora crassa  

E-Print Network [OSTI]

FRQ/WCC oscillator, several lines of evidence have implied the presence of other oscillators which may have important functions in the N. crassa circadian clock system. However, the molecular details are only known for the core FRQ/WCC oscillator...

Huang, He

2009-05-15T23:59:59.000Z

290

The harmonic oscillator with dissipation within the theory of open quantum systems  

E-Print Network [OSTI]

Time evolution of the expectation values of various dynamical operators of the harmonic oscillator with dissipation is analitically obtained within the framework of the Lindblad theory for open quantum systems. We deduce the density matrix of the damped harmonic oscillator from the solution of the Fokker-Planck equation for the coherent state representation, obtained from the master equation for the density operator. The Fokker-Planck equation for the Wigner distribution function, subject to either the Gaussian type or the $\\delta$-function type of initial conditions, is also solved by using the Wang-Uhlenbeck method. The obtained Wigner functions are two-dimensional Gaussians with different widths.

A. Isar

2005-08-18T23:59:59.000Z

291

New wave equation for ultrarelativistic particles  

E-Print Network [OSTI]

Starting from first principles and general assumptions based on the energy-momentum relation of the Special Theory of Relativity we present a novel wave equation for ultrarelativistic matter. This wave equation arises when particles satisfy the condition, $p>>m$, i.e, when the energy-momentum relation can be approximated by, $E\\simeq p+\\frac{m^{2}}{2p}$. Interestingly enough, such as the Dirac equation, it is found that this wave equation includes spin in a natural way. Furthermore, the free solutions of this wave equation contain plane waves that are completely equivalent to those of the theory of neutrino oscillations. Therefore, the theory reproduces some standard results of the Dirac theory in the limit $p>>m$, but offers the possibility of an explicit Lorentz Invariance Violation of order, $\\mathcal{O}((mc)^{4}/p^{2})$. As a result, the theory could be useful to test small departures from Dirac equation and Lorentz Invariance at very high energies. On the other hand, the wave equation can also describe particles of spin 1 by a simple substitution of the spin operators, $\\boldsymbol{\\sigma}\\rightarrow\\boldsymbol{\\alpha}$. In addition, it naturally admits a Lagrangian formulation and a Hamiltonian formalism. We also discuss the associated conservation laws that arise through the symmetry transformations of the Lagrangian.

Ginés R. Pérez Teruel

2014-12-15T23:59:59.000Z

292

The oscillations of a magnetic flux tube and its application to sunspots  

SciTech Connect (OSTI)

The modes of oscillation of an isolated magnetic flux tube in the absence of gravity is examined, with parameters chosen to mimic a sunspot. Gravitational stratification of the umbral atmosphere leads to consider two cases, distinguished primarily by the ordering of the Alfven speed and the external sound speed. The transition between these two regimes occurs at about the level where the optical depth, tau(c), is equal to 1 in the umbra. The modes given by the model, taken together with the observations, suggest that 3 minute oscillations are slow-body modes (driven by overstable convection) and that a sunspot consists of a bundle of pore-sized flux tubes rather than a single monolithic one. Fast-body modes are identified in the tube with the observed 5 minute oscillations of the umbral photosphere and below. The excitation of these modes propagating up or down the tube may explain the recent observation that sunspots act as sinks for p-modes propagating in their environment. Running penumbral waves are associated with fast- and slow-surface modes. The fast-surface wave could arise from fast-body modes driven below the level where tau(c) = 1; the slow-surface waves may arise from granular buffeting or overstable convection. 55 refs.

Evans, D.J.; Roberts, B. (Saint Andrews Univ. (Scotland))

1990-01-01T23:59:59.000Z

293

Self-oscillation in spin torque oscillator stabilized by field-like torque  

SciTech Connect (OSTI)

The effect of the field-like torque on the self-oscillation of the magnetization in spin torque oscillator with a perpendicularly magnetized free layer was studied theoretically. A stable self-oscillation at zero field is excited for negative ? while the magnetization dynamics stops for ??=?0 or ??>?0, where ? is the ratio between the spin torque and the field-like torque. The reason why only the negative ? induces the self-oscillation was explained from the view point of the energy balance between the spin torque and the damping. The oscillation power and frequency for various ? were also studied by numerical simulation.

Taniguchi, Tomohiro; Tsunegi, Sumito; Kubota, Hitoshi; Imamura, Hiroshi [National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba 305-8568 (Japan)

2014-04-14T23:59:59.000Z

294

Petrovay: Solar physics Helioseismology SOLAR OSCILLATIONS: INTRODUCTION  

E-Print Network [OSTI]

: Solar oscillations first observed by both Doppler and intensity method (Leighton, Noyes & Simon 1962: ApPetrovay: Solar physics Helioseismology SOLAR OSCILLATIONS: INTRODUCTION Small departures from hydrostatic equilibrium caused by ­ turbulent convection ­ localized events related to solar activity (e

Petrovay, Kristóf

295

February 2002 Grid Scale Oscillations in MICOM  

E-Print Network [OSTI]

are the implications of the grid scale oscillation on ­ Surface Fluxes that drive THC ­ Heat transport ­ MeridionalFebruary 2002 Grid Scale Oscillations in MICOM Balasubramanya T. Nadiga Los Alamos National Model · 3o displaced pole grid. 16 layers · Kraus-Turner Bulk Mixed Layer · Explicit diapycnal

Nadiga, Balasubramanya T. "Balu"

296

Wave propagation in highly inhomogeneous thin films: exactly solvable models  

E-Print Network [OSTI]

Wave propagation in highly inhomogeneous thin films: exactly solvable models Guillaume Petite(1 of wave propagation in some inhomogeneous thin films with highly space- dependent dielectric constant will show that depending on the type of space dependence, an incident wave can either propagate or tunnel

Boyer, Edmond

297

Behavioral/Systems/Cognitive Synchronous, Focally Modulated -Band Oscillations  

E-Print Network [OSTI]

, primarily synchronous -band voltage oscillations occur in the sensorimotor and frontal cortex of humansBehavioral/Systems/Cognitive Synchronous, Focally Modulated -Band Oscillations Characterize Local oscillations in the -frequency band ( 15­30Hz

Graybiel, Ann M.

298

Chemical sensor with oscillating cantilevered probe  

DOE Patents [OSTI]

The invention provides a method of detecting a chemical species with an oscillating cantilevered probe. A cantilevered beam is driven into oscillation with a drive mechanism coupled to the cantilevered beam. A free end of the oscillating cantilevered beam is tapped against a mechanical stop coupled to a base end of the cantilevered beam. An amplitude of the oscillating cantilevered beam is measured with a sense mechanism coupled to the cantilevered beam. A treated portion of the cantilevered beam is exposed to the chemical species, wherein the cantilevered beam bends when exposed to the chemical species. A second amplitude of the oscillating cantilevered beam is measured, and the chemical species is determined based on the measured amplitudes.

Adams, Jesse D

2013-02-05T23:59:59.000Z

299

Electromagnetic Waves in the De Sitter Space  

E-Print Network [OSTI]

5-Dimensional wave equation for a massive particle of spin 1 in the background of de Sitter space-time model is solved in static coordinates. The spherical 5-dimensional vectors $A_{a}, a= 1,...,5$ of three types, $j,j+1, j-1$ are constructed. In massless case they give electromagnetic wave solutions, obeying the Lorentz condition. 5-form of equations in massless case is used to produce recipe to build electromagnetic wave solutions of the types $\\Pi, E,M$; the first is trivial and can be removed by a gauge ransformation. The recipe is specified to produce spherical $\\Pi, E, M$ solutions in static coordinates.

V. S. Otchik; V. M. Red'kov

2010-01-24T23:59:59.000Z

300

Plane waves Lumped systems  

E-Print Network [OSTI]

1 Impedance · Plane waves ­ Lumped systems S x y z Impedance · Plane waves ­ Lumped systems · open tube #12;2 Impedance · Plane waves ­ Lumped systems · closed tube Impedance · Cylindrical waves z x y r #12;3 Impedance · Cylindrical waves ­ Circumferential part n=0 n=1 n=2 n=3 Impedance · Cylindrical

Berlin,Technische Universität

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Oscillation of Capacitance inside Nanopores  

SciTech Connect (OSTI)

materials for supercapacitors. Although great attention has been given to the anomalous increase of the capacitance as the pore size approaches the ionic dimensions, there remains a lack of full comprehension of the size dependence of the capacitance in nanopores. Here we predict from a classical density functional theory that the capacitance of an ionic-liquid electrolyte inside a nanopore oscillates with a decaying envelope as the pore size increases. The oscillatory behavior can be attributed to the interference of the overlapping electric double layers (EDLs); namely, the maxima in capacitance appear when superposition of the two EDLs is most constructive. The theoretical prediction agreeswell with the experiment when the pore size is less than twice the ionic diameter.Confirmation of the entire oscillatory spectruminvites future experiments with a precise control of the pore size from micro- to mesoscales.

Jiang, Deen [ORNL; Wu, Jianzhong [University of California, Riverside; Jin, Zhehui [University of California, Riverside

2011-01-01T23:59:59.000Z

302

Pulse combustor with controllable oscillations  

DOE Patents [OSTI]

A pulse combustor having thermally induced pulse combustion in a continuously flowing system is described. The pulse combustor is fitted with at lease one elongated ceramic body which significantly increases the heat transfer area in the combustion chamber of the combustor. The ceramic body or bodies possess sufficient mass and heat capacity to ignite the fuel-air charge once the ceramic body or bodies are heated by conventional spark plug initiated combustion so as to provide repetitive ignition and combustion of sequentially introduced fuel-air charges without the assistance of the spark plug and the rapid quenching of the flame after each ignition in a controlled manner so as to provide a selective control over the oscillation frequency and amplitude. Additional control over the heat transfer in the combustion chamber is provided by employing heat exchange mechanisms for selectively heating or cooling the elongated ceramic body or bodies and/or the walls of the combustion chamber.

Richards, George A. (Morgantown, WV); Welter, Michael J. (Columbiana, OH); Morris, Gary J. (Morgantown, WV)

1992-01-01T23:59:59.000Z

303

Wave turbulence revisited: Where does the energy flow?  

E-Print Network [OSTI]

Turbulence in a system of nonlinearly interacting waves is referred to as wave turbulence. It has been known since seminal work by Kolmogorov, that turbulent dynamics is controlled by a directional energy flux through the wavelength scales. We demonstrate that an energy cascade in wave turbulence can be bi-directional, that is, can simultaneously flow towards large and small wavelength scales from the pumping scales at which it is injected. This observation is in sharp contrast to existing experiments and wave turbulence theory where the energy flux only flows in one direction. We demonstrate that the bi-directional energy cascade changes the energy budget in the system and leads to formation of large-scale, large-amplitude waves similar to oceanic rogue waves. To study surface wave turbulence, we took advantage of capillary waves on a free, weakly charged surface of superfluid helium He-II at temperature 1.7K. Although He-II demonstrates non-classical thermomechanical effects and quantized vorticity, waves on its surface are identical to those on a classical Newtonian fluid with extremely low viscosity. The possibility of directly driving a charged surface by an oscillating electric field and the low viscosity of He-II have allowed us to isolate the surface dynamics and study nonlinear surface waves in a range of frequencies much wider than in experiments with classical fluids.

L. V. Abdurakhimov; I. A. Remizov; A. A. Levchenko; G. V. Kolmakov; Y. V. Lvov

2014-04-03T23:59:59.000Z

304

Wave propagation and shock formation in different magnetic structures  

E-Print Network [OSTI]

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave propagation as a function of the magnetic flux of the structure (i.e. two different-sized sunspots, a tiny pore and a facular region). While photospheric oscillations have similar characteristics everywhere, oscillations measured at chromospheric heights show different amplitudes, frequencies and stages of shock development depending on the observed magnetic feature. The analysis of the power and the phase spectra, together with simple theoretical modeling, lead to a series of results concerning wave propagation within the range of heights of this study. We find that, while the atmospheric cut-off frequency and the propagation properties of the different oscillating modes depend on the magnetic feature, in all the cases the power that reaches the high chromosphere above the atmospheric cut-off comes directly from the photosphere by means of linear vertical wave propagation rather than from non-linear interaction of modes.

Rebecca Centeno; Manuel Collados; Javier Trujillo Bueno

2008-10-20T23:59:59.000Z

305

Surface electromagnetic wave equations in a warm magnetized quantum plasma  

SciTech Connect (OSTI)

Based on the single-fluid plasma model, a theoretical investigation of surface electromagnetic waves in a warm quantum magnetized inhomogeneous plasma is presented. The surface electromagnetic waves are assumed to propagate on the plane between a vacuum and a warm quantum magnetized plasma. The quantum magnetohydrodynamic model includes quantum diffraction effect (Bohm potential), and quantum statistical pressure is used to derive the new dispersion relation of surface electromagnetic waves. And the general dispersion relation is analyzed in some special cases of interest. It is shown that surface plasma oscillations can be propagated due to quantum effects, and the propagation velocity is enhanced. Furthermore, the external magnetic field has a significant effect on surface wave's dispersion equation. Our work should be of a useful tool for investigating the physical characteristic of surface waves and physical properties of the bounded quantum plasmas.

Li, Chunhua; Yang, Weihong [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Wu, Zhengwei, E-mail: wuzw@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Center of Low Temperature Plasma Application, Yunnan Aerospace Industry Company, Kunming, 650229 Yunnan (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2014-07-15T23:59:59.000Z

306

Interaction of two walkers: Wave-mediated energy and force  

E-Print Network [OSTI]

A bouncing droplet, self-propelled by its interaction with the waves it generates, forms a classical wave-particle association called a "walker." Previous works have demonstrated that the dynamics of a single walker is driven by its global surface wave field that retains information on its past trajectory. Here, we investigate the energy stored in this wave field for two coupled walkers and how it conveys an interaction between them. For this purpose, we characterize experimentally the "promenade modes" where two walkers are bound, and propagate together. Their possible binding distances take discrete values, and the velocity of the pair depends on their mutual binding. The mean parallel motion can be either rectilinear or oscillating. The experimental results are recovered analytically with a simple theoretical framework. A relation between the kinetic energy of the droplets and the total energy of the standing waves is established.

Borghesi, Christian; Labousse, Matthieu; Eddi, Antonin; Fort, Emmanuel; Couder, Yves

2014-01-01T23:59:59.000Z

307

Flavor Oscillation from the Two-Point Function  

E-Print Network [OSTI]

We present a formalism for the flavor oscillation of unstable particles that relies only upon the structure of the time Fourier-transformed two-point Green's function. We derive exact oscillation probability and integrated oscillation probability formulae, and verify that our results reproduce the known results for both neutrino and neutral meson oscillation in the expected regimes of parameter space. The generality of our approach permits us to investigate flavor oscillation in exotic parameter regimes, and present the corresponding oscillation formulae.

Mario Martone; Dean J. Robinson

2011-10-25T23:59:59.000Z

308

Wave-Packet Revivals for Quantum Systems with Nondegenerate Energies  

E-Print Network [OSTI]

The revival structure of wave packets is examined for quantum systems having energies that depend on two nondegenerate quantum numbers. For such systems, the evolution of the wave packet is controlled by two classical periods and three revival times. These wave packets exhibit quantum beats in the initial motion as well as new types of long-term revivals. The issue of whether fractional revivals can form is addressed. We present an analytical proof showing that at certain times equal to rational fractions of the revival times the wave packet can reform as a sum of subsidiary waves and that both conventional and new types of fractional revivals can occur.

Robert Bluhm; Alan Kostelecky; Bogdan Tudose

1996-09-26T23:59:59.000Z

309

Forced oscillations in magnetized accretion disks and QPOs  

E-Print Network [OSTI]

We propose a new model for these QPOs based on forced oscillations induced in the accretion disk due to the stellar magnetic field. First, it is shown that a magnetized accretion disk evolving in a rotating nonaxisymmetric magnetic field anchored to a neutron star will be subject to three kinds of resonances: a corotation resonance, a Lindblad resonance due to a driving force, and a parametric resonance due to the time varying epicyclic frequencies. In the second part of the paper, we focus on the linear response of a thin accretion disk, developing the density perturbation as the sum of free wave solutions and non-wavelike disturbances. In the last part, we show results of 2D numerical simulations of a simplified version of the accretion disk consisting of a column of plasma threaded by a vertical magnetic field. It is argued that the nearly periodic motion induced in the disk will produce high quality factor QPOs.

J. Pétri

2005-07-06T23:59:59.000Z

310

accuracy neutrino oscillation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay. G. Rajasekaran 2000-04-17 22 Neutrino Mass and Oscillation HEP -...

311

Increasing LTC Engine Efficiency by Reducing Pressure-Oscillation...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Increasing LTC Engine Efficiency by Reducing Pressure-Oscillation-Related Heat Transfer Losses Increasing LTC Engine Efficiency by Reducing Pressure-Oscillation-Related Heat...

312

Neutron-Mirror-Neutron Oscillations in a Trap  

E-Print Network [OSTI]

We calculate the rate of neutron-mirror-neutron oscillations for ultracold neutrons trapped in a storage vessel. Recent experimental bounds on the oscillation time are discussed.

B. Kerbikov; O. Lychkovskiy

2008-04-03T23:59:59.000Z

313

Dressed-state approach to matter-wave mixing of bosons  

SciTech Connect (OSTI)

A dressed-state approach to mixing of bosonic matter waves is presented. Two cases are studied using this formalism. In the first, two macroscopically populated modes of atoms (two-wave mixing) are coupled through the presence of light. In the second case, three modes of Bogoliubov quasiparticles (three-wave mixing) are coupled through s-wave interaction. In both cases, wave mixing induces oscillations in the population of the different modes that decay due to interactions. Analytic expressions for the dressed basis spectrum and the evolution of the mode populations in time are derived both for resonant mixing and nonresonant mixing. Oscillations in the population of a given mode are shown to lead to a splitting in the decay spectrum of that mode, in analogy with the optical Autler-Townes splitting in the decay spectrum of a strongly driven atom. These effects cannot be described by a mean-field approximation.

Rowen, E.; Ozeri, R.; Katz, N.; Pugatch, R.; Davidson, N. [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)

2005-11-15T23:59:59.000Z

314

Smooth sandwich gravitational waves  

E-Print Network [OSTI]

Gravitational waves which are smooth and contain two asymptotically flat regions are constructed from the homogeneous pp-waves vacuum solution. Motion of free test particles is calculated explicitly and the limit to an impulsive wave is also considered.

J. Podolsky

1998-07-16T23:59:59.000Z

315

Constraining the gravitational wave energy density of the Universe using Earth's ring  

E-Print Network [OSTI]

The search for gravitational waves is one of today's major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode oscillations ring up when a gravitational wave passes. Therefore, precise measurement of vibration amplitudes can be used to search for the elusive gravitational-wave signals. Earth's free oscillations that can be observed after high-magnitude earthquakes have been studied extensively with gravimeters and low-frequency seismometers over many decades leading to invaluable insight into Earth's structure. Making use of our detailed understanding of Earth's normal modes, numerical models are employed for the first time to accurately calculate Earth's gravitational-wave response, and thereby turn a network of sensors that so far has served to improve our understanding of Earth, into an astrophysical observatory exploring our Universe. In this article, we constrain the energy density of gravitational waves to values in the range 0.035 - 0.15 normalized by the critical energy density of the Universe at frequencies between 0.3mHz and 5mHz, using 10 years of data from the gravimeter network of the Global Geodynamics Project that continuously monitors Earth's oscillations. This work is the first step towards a systematic investigation of the sensitivity of gravimeter networks to gravitational waves. Further advance in gravimeter technology could improve sensitivity of these networks and possibly lead to gravitational-wave detection.

Michael Coughlin; Jan Harms

2014-06-04T23:59:59.000Z

316

Jumping solitary waves in an autonomous reactiondiffusion system with subcritical wave instability  

E-Print Network [OSTI]

Jumping solitary waves in an autonomous reaction­diffusion system with subcritical wave instability as solutions to a reaction­diffusion system with a subcritical short-wavelength instability. We demonstrate systems with a subcritical oscillatory instability.17 Here we present a new type of solitary traveling

Epstein, Irving R.

317

Influence of the backward propagating waves on the threshold in planar nematic liquid crystal films  

E-Print Network [OSTI]

We analyze theoretically the influence of backward propagating waves on the primary threshold when a linearly polarized light impinges at normal incidence on a planarly aligned nematic liquid crystal films. We show, that the primary threshold, as a function of the phase delay induced by the nematic layer, exhibits oscillations. The amplitude of oscillations depends strongly on the drop of the refractivity indices of the nematic and outer media at the boundaries.

Dmitry O. Krimer; Andrey E. Miroshnichenko; Etienne Brasselet

2010-10-19T23:59:59.000Z

318

Oscillation modes of dc microdischarges with parallel-plate geometry  

E-Print Network [OSTI]

Two different oscillation modes in microdischarge with parallel-plate geometry has been observed: relaxation oscillations with frequency range between 1.23 and 2.1 kHz and free-running oscillations with 7 kHz frequency. The oscillation modes are induced by increasing power supply voltage or discharge current. For a given power supply voltage, there is a spontaneous transition from one to other oscillation mode and vice versa. Before the transition from relaxation to free-running oscillations, the spontaneous increase of oscillation frequency of relaxation oscillations form 1.3 kHz to 2.1 kHz is measured. Fourier Transform Spectra of relaxation oscillations reveal chaotic behaviour of microdischarge. Volt-Ampere characteristics associated with relaxation oscillations describes periodical transition between low current, diffuse discharge and normal glow. However, free-running oscillations appear in subnormal glow only.

Stefanovi?, Ilija; Škoro, Nikola; Mari?, Dragana; Petrovi?, Zoran Lj; Winter, Jörg

2011-01-01T23:59:59.000Z

319

Fast Computation Algorithm for Discrete Resonances among Gravity Waves  

E-Print Network [OSTI]

Traditionally resonant interactions among short waves, with large real wave-numbers, were described statistically and only a small domain in spectral space with integer wave-numbers, discrete resonances, had to be studied separately in resonators. Numerical simulations of the last few years showed unambiguously the existence of some discrete effects in the short-waves part of the wave spectrum. Newly presented model of laminated turbulence explains theoretically appearance of these effects thus putting a novel problem - construction of fast algorithms for computation of solutions of resonance conditions with integer wave-numbers of order $10^3$ and more. Example of such an algorithm for 4-waves interactions of gravity waves is given. Its generalization on the different types of waves is briefly discussed.

Elena Kartashova

2006-05-25T23:59:59.000Z

320

Self-seeding ring optical parametric oscillator  

DOE Patents [OSTI]

An optical parametric oscillator apparatus utilizing self-seeding with an external nanosecond-duration pump source to generate a seed pulse resulting in increased conversion efficiency. An optical parametric oscillator with a ring configuration are combined with a pump that injection seeds the optical parametric oscillator with a nanosecond duration, mJ pulse in the reverse direction as the main pulse. A retroreflecting means outside the cavity injects the seed pulse back into the cavity in the direction of the main pulse to seed the main pulse, resulting in higher conversion efficiency.

Smith, Arlee V. (Albuquerque, NM); Armstrong, Darrell J. (Albuquerque, NM)

2005-12-27T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Axion Induced Oscillating Electric Dipole Moments  

E-Print Network [OSTI]

The axion electromagnetic anomaly induces an oscillating electric dipole for any static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency $m_a$ and strength $\\sim 10^{-32}$ e-cm, two orders of magnitude above the nucleon, and within four orders of magnitude of the present standard model DC limit. This may suggest sensitive new experimental venues for the axion dark matter search.

Hill, Christopher T

2015-01-01T23:59:59.000Z

322

Feedback Control Of An Azimuthal Oscillation In The ExB Discharge of Hall Thrusters  

SciTech Connect (OSTI)

Feedback control of a low-frequency azimuthal wave known as a "rotating spoke" in the ExB discharge of a cylindrical Hall thruster was demonstrated. The rotating spoke is an m=1 azimuthal variation in density, electron temperature, and potential that rotates at about 10% of the local E x B electron rotation speed. It causes increased electron transport across the magnetic field and is suspected to be an ionization wave. Feedback control of this wave required special consideration because, although it causes a rotating azimuthal variation in the current density to the anode, it does not show up as a signal in the total thruster discharge current. Therefore, an extra source of information was needed to track the oscillation, which was addressed by using a special anode that was split azimuthally into four segments. The current to each segment oscillates as the rotating spoke passes over it, and feedback is accomplished by resistors connected in series with each anode segment which cause the voltage on a segment to decrease in proportion to the current through that segment. The feedback resulted in the disappearance of a coherent azimuthal wave and a decrease in the time-averaged total discharge current by up to 13.2%.

Griswold, Martin E.; Ellison, C. L.; Raitses, Y.; Fisch, N. J.

2012-04-06T23:59:59.000Z

323

EVIDENCE FOR THE IMPACT OF STELLAR ACTIVITY ON THE DETECTABILITY OF SOLAR-LIKE OSCILLATIONS OBSERVED BY KEPLER  

SciTech Connect (OSTI)

We use photometric observations of solar-type stars, made by the NASA Kepler Mission, to conduct a statistical study of the impact of stellar surface activity on the detectability of solar-like oscillations. We find that the number of stars with detected oscillations falls significantly with increasing levels of activity. The results present strong evidence for the impact of magnetic activity on the properties of near-surface convection in the stars, which appears to inhibit the amplitudes of the stochastically excited, intrinsically damped solar-like oscillations.

Chaplin, W. J.; Broomhall, A.-M.; Hekker, S.; Elsworth, Y.; Stevens, I. R. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Bedding, T. R.; Huber, D. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Bonanno, A. [INAF Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123, Catania (Italy); GarcIa, R. A. [Laboratoire AIM, CEA/DSM, CNRS, Universite Paris Diderot, IRFU/SAp, 91191 Gif-sur-Yvette Cedex (France); Verner, G. A. [Astronomy Unit, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom); Basu, S. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Houdek, G. [Institute of Astronomy, University of Vienna, A-1180 Vienna (Austria); Mathur, S.; Metcalfe, T. S. [High Altitude Observatory and, Scientific Computing Division, National Center for Atmospheric Research, Boulder, Colorado 80307 (United States); Mosser, B. [LESIA, CNRS, Universite Pierre et Marie Curie, Universite Denis Diderot, Observatoire de Paris, 92195 Meudon Cedex (France); New, R. [Materials Engineering Research Institute, Faculty of Arts, Computing, Engineering and Sciences, Sheffield Hallam University, Sheffield, S1 1WB (United Kingdom); Appourchaux, T. [Institut d'Astrophysique Spatiale, Universite Paris XI, CNRS (UMR8617), Batiment 121, 91405 Orsay Cedex (France); Karoff, C. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Molenda-Zakowicz, J. [Astronomical Institute, University of Wroclaw, ul. Kopernika, 11, 51-622 Wroclaw (Poland); Monteiro, M. J. P. F. G. [Centro de Astrofisica and Faculdade de Ciencias, Universidade do Porto, Rua das Estrelas, 4150-762 (Portugal)

2011-05-01T23:59:59.000Z

324

Gamma Oscillation by Synaptic Inhibition in a Hippocampal Interneuronal Network Model  

E-Print Network [OSTI]

both EPSPs and IPSPs phase-locked to the field oscillation frequencies (Jagadeesh et al., 1992; Chen and Sompolinsky, 1996). Traditionally, recurrent excitation between principal (pyramidal) neurons is viewed excitation of the AMPA type usually desynchronizes rather than synchronizes re- petitive spike firings

Wang, Xiao-Jing

325

The Intraseasonal Oscillation and the Energetics of Summertime Tropical Western North Pacific  

E-Print Network [OSTI]

The Intraseasonal Oscillation and the Energetics of Summertime Tropical Western North Pacific University of New York Albany, New York Journal of the Atmospheric Sciences Submitted October 14, 2002 the energetics of tropical depression (TD)-type disturbances. An energetics analysis is conducted with NCEP

Maloney, Eric

326

Stars as resonant absorbers of gravitational waves  

E-Print Network [OSTI]

Quadrupole oscillation modes in stars can resonate with incident gravitational waves (GWs), and grow non-linear at the expense of GW energy. Stars near massive black hole binaries (MBHB) can act as GW-charged batteries, cooling radiatively. Mass-loss from these stars can prompt MBHB accretion at near-Eddington rates. GW opacity is independent of amplitude, so distant resonating stars can eclipse GW sources. Absorption by the Sun of GWs from Galactic white dwarf binaries may be detectable with second-generation space-based GW detectors as a shadow within a complex diffraction pattern.

B. McKernan; K. E. S. Ford; B. Kocsis; Z. Haiman

2014-08-28T23:59:59.000Z

327

Torsional oscillations of strange stars  

E-Print Network [OSTI]

Strange stars are one of the hypothetical compact stellar objects that can be formed after a supernova explosion. The existence of these objects relies on the absolute stability of strange {\\it collapsed} quark matter with respect to standard nuclear matter. We discuss simple models of strange stars with a bare quark matter surface, thus standard nuclear matter is completely absent. In these models an electric dipole layer a few hundreds Fermi thick should exist close to the star surface. Studying the torsional oscillations of the electrically charged layer we estimate the emitted power, finding that it is of the order of $10^{45}$ erg/s, meaning that these objects would be among the brightest compact sources in the heavens. The associated relaxation times are very uncertain, with values ranging between microseconds and minutes, depending on the crust thickness. Although part of the radiated power should be absorbed by the electrosphere surrounding the strange star, a sizable fraction of photons should escape and be detectable.

Massimo Mannarelli

2014-09-12T23:59:59.000Z

328

Noncommutative quantum mechanics of simple matter systems interacting with circularly polarized gravitational waves  

E-Print Network [OSTI]

The response of a test particle, both for the free case and under the harmonic oscillator potential, to circularly polarized gravitational waves is investigated in a noncommutative quantum mechanical setting. The system is quantized following the prescription in \\cite{ncgw1}. Standard algebraic techniques are then employed to solve the Hamiltonian of the system. The solutions, in both cases, show signatures of the coordinate noncommutativity. In the harmonic oscillator case, this signature plays a key role in altering the resonance point and the oscillation frequency of the system.

Sunandan Gangopadhyay; Anirban Saha; Swarup Saha

2014-09-11T23:59:59.000Z

329

Wave Propagation in Lipid Monolayers  

E-Print Network [OSTI]

Sound waves are excited on lipid monolayers using a set of planar electrodes aligned in parallel with the excitable medium. By measuring the frequency dependent change in the lateral pressure we are able to extract the sound velocity for the entire monolayer phase diagram. We demonstrate that this velocity can also be directly derived from the lipid monolayer compressibility and consequently displays a minimum in the phase transition regime. This minimum decreases from v0=170m/s for one component lipid monolayers down to vm=50m/s for lipid mixtures. No significant attenuation can be detected confirming an adiabatic phenomenon. Finally our data propose a relative lateral density oscillation of \\Delta\\rho/\\rho ~ 2% implying a change in all area dependent physical properties. Order of magnitude estimates from static couplings therefore predict propagating changes in surface potential of 1-50mV, 1 unit in pH (electrochemical potential) and 0.01{\\deg}K in temperature and fall within the same order of magnitude as physical changes measured during nerve pulse propagation. These results therefore strongly support the idea of propagating adiabatic sound waves along nerves as first thoroughly described by Kaufmann in 1989 and recently by Heimburg and Jackson, but claimed by Wilke already in 1912.

J. Griesbauer; A. Wixforth; M. F. Schneider

2010-05-26T23:59:59.000Z

330

Experimental investigation of a coaxial gyrotron oscillator  

E-Print Network [OSTI]

This thesis presents experimental results of a megawatt power level, 140 GHz coaxial gyrotron oscillator. The coaxial gyrotron has the potential to transport very high power electron beams and thus achieve higher microwave ...

Advani, Rahul N

1999-01-01T23:59:59.000Z

331

Solar mass-varying neutrino oscillations  

E-Print Network [OSTI]

We propose that the solar neutrino deficit may be due to oscillations of mass-varying neutrinos (MaVaNs). This scenario elucidates solar neutrino data beautifully while remaining comfortably compatible with atmospheric neutrino and K2K data...

Marfatia, Danny; Huber, P.; Barger, V.

2005-11-18T23:59:59.000Z

332

Analysis of oscillating flow cooled SMA actuator  

E-Print Network [OSTI]

literature, most of the cooling mechanisms involve unidirectional forced convection. This may not be the most effective method. Oscillating flow in a channel can sometimes enhance heat transfer over a unidirectional flow. One possible explanation...

Pachalla Seshadri, Rajagopal

2005-11-01T23:59:59.000Z

333

Spatial xenon oscillation control with expert systems  

SciTech Connect (OSTI)

Spatial power oscillations were attributed to the xenon transients in a reactor core in 1958 by Randall and St. John. These transients are usually initiated by a local reactivity insertion and lead to divergent axial flux oscillations in the core at constant power. Several heuristic manual control strategies and automatic control methods were developed to damp the xenon oscillations at constant power operations. However, after the load-follow operation of the reactors became a necessity of life, a need for better control strategies arose. Even though various advanced control strategies were applied to solve the xenon oscillation control problem for the load-follow operation, the complexity of the system created difficulties in modeling. The strong nonlinearity of the problem requires highly sophisticated analytical approaches that are quite inept for numerical solutions. On the other hand, the complexity of a system and heuristic nature of the solutions are the basic reasons for using artificial intelligence techniques such as expert systems.

Alten, S. (Turkish Atomic Energy Authority, Ankara (Turkey)); Danofsky, R.A. (Iowa State Univ., Ames, IA (United States))

1993-01-01T23:59:59.000Z

334

CFD analysis of laminar oscillating flows  

SciTech Connect (OSTI)

This paper describes a numerical simulations of oscillating flow in a constricted duct and compares the results with experimental and theoretical data. The numerical simulations were performed using the computational fluid dynamics (CFD) code CFX4.2. The numerical model simulates an experimental oscillating flow facility that was designed to test the properties and characteristics of oscillating flow in tapered ducts, also known as jet pumps. Jet pumps are useful devices in thermoacoustic machinery because they produce a secondary pressure that can counteract an unwanted effect called streaming, and significantly enhance engine efficiency. The simulations revealed that CFX could accurately model velocity, shear stress and pressure variations in laminar oscillating flow. The numerical results were compared to experimental data and theoretical predictions with varying success. The least accurate numerical results were obtained when laminar flow approached transition to turbulent flow.

Booten, C. W. Charles W.); Konecni, S. (Snezana); Smith, B. L. (Barton L.); Martin, R. A. (Richard A.)

2001-01-01T23:59:59.000Z

335

Oscillations in the GSI electron capture experiment  

E-Print Network [OSTI]

In a recent paper, oscillations observed in the electron capture probability were attributed to the mixing of neutrino mass eigenstates. This paper is shown to be in error in two respects.

H. Burkhardt; J. Lowe; G. J. Stephenson Jr.; T. Goldman; and Bruce H. J. McKellar

2008-04-07T23:59:59.000Z

336

The Case for Strategic Oscillation Fred Glover  

E-Print Network [OSTI]

for Strategic Oscillation Fred Glover OptTek Systems, Inc., 1919 Seventh Street, Boulder, CO 80302 USA glover implications for future research. Manuscript Click here to download Manuscript: ANOR Glover and Jin

Hao, Jin-Kao

337

Chimera States in Mechanical Oscillator Networks  

E-Print Network [OSTI]

The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature employs to orchestrate essential processes of life, such as the beating of the heart. While it was long thought that synchrony or disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years revealed the intriguing possibility of 'chimera states', in which the symmetry of the oscillator population is broken into a synchronous and an asynchronous part. However, a striking lack of empirical evidence raises the question of whether chimeras are indeed characteristic to natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled in a hierarchical network to show that chimeras emerge naturally from a competition between two antagonistic synchronization patte...

Martens, Erik Andreas; Fourrière, Antoine; Hallatschek, Oskar

2013-01-01T23:59:59.000Z

338

Chimeras in networks of planar oscillators  

E-Print Network [OSTI]

Chimera states occur in networks of coupled oscillators, and are characterized by having some fraction of the oscillators perfectly synchronized, while the remainder are desynchronized. Most chimera states have been observed in networks of phase oscillators with coupling via a sinusoidal function of phase differences, and it is only for such networks that any analysis has been performed. Here we present the first analysis of chimera states in a network of planar oscillators, each of which is described by both an amplitude and a phase. We find that as the attractivity of the underlying periodic orbit is reduced chimeras are destroyed in saddle-node bifurcations, and supercritical Hopf and homoclinic bifurcations of chimeras also occur.

Carlo R. Laing

2010-06-23T23:59:59.000Z

339

Theoretical and experimental investigation of axial power extraction from a magnetically insulated transmission line oscillator  

SciTech Connect (OSTI)

The utility of the magnetically insulated transmission line oscillator (MILO) as a high power microwave source depends on how efficiently power can be extracted from it. We have designed a slow-wave stepped transformer for the purpose of axially extracting microwave power from a 3.6 GHz coaxial MILO. The slow-wave transformer design was optimized using particle-in-cell simulation, and tested in experiments performed on the HPM Simulation Division's GEMINI and GYPSY water Blumlein pulse power sources. In this paper we summarize the slow-wave stepped transformer design, and describe MILO axial power extraction experiments which yielded up to 300 MW of radiated power. 10 refs., 4 figs., 2 tabs.

Lemke, R.W.; DeMuth, G.E.; Biggs, A.W. (Sandia National Labs., Albuquerque, NM (USA); Air Force Weapons Lab., Kirtland AFB, NM (USA); Alabama Univ., Huntsville, AL (USA). Dept. of Electrical and Computer Engineering)

1989-01-01T23:59:59.000Z

340

Synchronization of Mechanical Oscillators: An Experimental Study  

E-Print Network [OSTI]

SYNCHRONIZATION OF MECHANICAL OSCILLATORS: AN EXPERIMENTAL STUDY A Thesis by ROOZBEH DANESHVAR Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE December... 2010 Major Subject: Electrical Engineering SYNCHRONIZATION OF MECHANICAL OSCILLATORS: AN EXPERIMENTAL STUDY A Thesis by ROOZBEH DANESHVAR Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements...

Daneshvar, Roozbeh

2011-02-22T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Chaos control of parametric driven Duffing oscillators  

SciTech Connect (OSTI)

Duffing resonators are typical dynamic systems, which can exhibit chaotic oscillations, subject to certain driving conditions. Chaotic oscillations of resonating systems with negative and positive spring constants are identified to investigate in this paper. Parametric driver imposed on these two systems affects nonlinear behaviours, which has been theoretically analyzed with regard to variation of driving parameters (frequency, amplitude). Systematic calculations have been performed for these two systems driven by parametric pumps to unveil the controllability of chaos.

Jin, Leisheng; Mei, Jie; Li, Lijie, E-mail: L.Li@swansea.ac.uk [College of Engineering, Swansea University, Swansea SA2 8PP (United Kingdom)

2014-03-31T23:59:59.000Z

342

Oscillation dynamics of multi-well condensates  

E-Print Network [OSTI]

We propose a new approach to the macroscopic dynamics of three-well Bose-Einstein condensates, giving particular emphasis to self-trapping and Josephson oscillations. Although these effects have been studied quite thoroughly in the mean-field approximation, a full quantum description is desirable, since it avoids pathologies due to the nonlinear character of the mean-field equations. Using superpositions of quantum eigenstates, we construct various oscillation and trapping scenarios.

S. Mossmann; C. Jung

2006-12-05T23:59:59.000Z

343

Newtonian gravity, red shift, confinement, asymptotic freedom and quarks oscillations  

E-Print Network [OSTI]

Quarks oscillations give the Newtonian gravity law, the red shift, the confinement and the asymptotic freedom.

G. Quznetsov

2008-10-18T23:59:59.000Z

344

Noise properties of mutually sustained microwave-optoelectronic oscillator pair  

E-Print Network [OSTI]

Noise properties of mutually sustained microwave-optoelectronic oscillator pair E. Shumakher and G microwave-optoelectronic oscillator pair are described. The two oscillators have different spectral purities and exhibits low phase noise and highly suppressed spurious modes. Optoelectronic oscillators are employed

Eisenstein, Gadi

345

An Accelerated Poincar e-map method for Autonomous Oscillators  

E-Print Network [OSTI]

An Accelerated Poincar#19;e-map method for Autonomous Oscillators S.H.M.J. Houben #3; and J between non-autonomous and autonomous oscillators. Non-autonomous (or driven) oscillators have a time. On the other hand, autonomous (or free-running) oscillators have no time-dependent in- put signal, which means

Eindhoven, Technische Universiteit

346

Neutrino oscillation signatures of oxygen-neon-magnesium supernovae  

E-Print Network [OSTI]

We discuss the flavor conversion of neutrinos from core collapse supernovae that have oxygen-neon-magnesium (ONeMg) cores. Using the numerically calculated evolution of the star up to 650 ms post bounce, we find that, for the normal mass hierarchy, the electron neutrino flux in a detector shows signatures of two typical features of an ONeMg-core supernova: a sharp step in the density profile at the base of the He shell and a faster shock wave propagation compared to iron core supernovae. Before the shock hits the density step (t ~ 150 ms), the survival probability of electron neutrinos is about 0.68, in contrast to values of 0.32 or less for an iron core supernova. The passage of the shock through the step and its subsequent propagation cause a decrease of the survival probability and a decrease of the amplitude of oscillations in the Earth, reflecting the transition to a more adiabatic propagation inside the star. These changes affect the lower energy neutrinos first; they are faster and more sizable for larger theta_13. They are unique of ONeMg-core supernovae, and give the possibility to test the speed of the shock wave. The time modulation of the Earth effect and its negative sign at the neutronization peak are the most robust signatures in a detector.

C. Lunardini; B. Mueller; H. -Th. Janka

2007-12-18T23:59:59.000Z

347

Water Waves Roger Grimshaw  

E-Print Network [OSTI]

,2) provide a kinematic description of water waves, which to this point means that the conditionsWater Waves Roger Grimshaw May 7, 2003 Abstract A short review of the theory of weakly nonlinear water waves, prepared for the forthcoming Encyclopedia of Nonlinear Science 1 Introduction Water waves

348

Oscillations During Thermonuclear X-ray Bursts  

E-Print Network [OSTI]

High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass- radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290 Hz) has been claimed.

Tod E. Strohmayer

2001-01-01T23:59:59.000Z

349

Oscillations During Thermonuclear X-ray Bursts  

E-Print Network [OSTI]

High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass - radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290 Hz) has been claimed.

Tod E. Strohmayer

2001-01-12T23:59:59.000Z

350

Coupled Langmuir oscillations in 2-dimensional quantum plasmas  

SciTech Connect (OSTI)

In this work, we present a hydrodynamic model to study the coupled quantum electron plasma oscillations (QEPO) for two dimensional (2D) degenerate plasmas, which incorporates all the essential quantum ingredients such as the statistical degeneracy pressure, electron-exchange, and electron quantum diffraction effect. Effects of diverse physical aspects like the electronic band-dispersion effect, the electron exchange-correlations and the quantum Bohm-potential as well as other important plasma parameters such as the coupling parameter (plasma separation) and the plasma electron number-densities on the linear response of the coupled system are investigated. By studying three different 2D plasma coupling types, namely, graphene-graphene, graphene-metalfilm, and metalfilm-metalfilm coupling configurations, it is remarked that the collective quantum effects can influence the coupled modes quite differently, depending on the type of the plasma configuration. It is also found that the slow and fast QEPO frequency modes respond very differently to the change in plasma parameters. Current findings can help in understanding of the coupled density oscillations in multilayer graphene, graphene-based heterojunctions, or nanofabricated integrated circuits.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz, Iran and International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany)] [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz, Iran and International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany)

2014-03-15T23:59:59.000Z

351

Emission Origin for the Wave of Quanta  

E-Print Network [OSTI]

We argue that certain assumptions about the process of the emission of the quanta by their (oscillating) emitter provide for their changing (oscillatory) flux at any location. This mechanism underlying (such) wave phenomena is not based, both, on the newtonian notion of force and the field concept (of Faraday, Maxwell, Lorentz and Einstein). When applied to the case of thermal radiation, this emission origin for the wave of quanta is shown here to be consistent with the laws of the black body radiation. We conclude therefore also that a conceptual framework, which is not rooted in the notion of force and in the field concept, may provide a deterministic basis underlying the probabilistic methods of the quantum theory.

Sanjay M Wagh

2009-07-07T23:59:59.000Z

352

Flows and Waves in Braided Solar Coronal Magnetic Structures  

E-Print Network [OSTI]

We study the high frequency dynamics in the braided magnetic structure of an active region (AR 11520) moss as observed by High-Resolution Coronal Imager (Hi-C). We detect quasi periodic flows and waves in these structures. We search for high frequency dynamics while looking at power maps of the observed region. We find that shorter periodicites (30 - 60 s) are associated with small spatial scales which can be resolved by Hi-C only. We detect quasi periodic flows with wide range of velocities from 13 - 185 km/s associated with braided regions. This can be interpreted as plasma outflows from reconnection sites. We also find presence of short period and large amplitude transverse oscillations associated with braided magnetic region. Such oscillations could be triggered by reconnection or such oscillation may trigger reconnection.

Pant, V; Banerjee, Dipankar

2015-01-01T23:59:59.000Z

353

MHD Wave Propagation in the Neighbourhood of Two Null Points  

E-Print Network [OSTI]

The nature of fast magnetoacoustic and Alfv\\'en waves is investigated in a zero $\\beta$ plasma in the neighbourhood of a pair of two-dimensional null points. This gives an indication of wave propagation in the low $\\beta$ solar corona, for a more complicated magnetic configuration than that looked at by McLaughlin & Hood (2004). It is found that the fast wave is attracted to the null points and that the front of the wave slows down as it approaches the null point pair, with the wave splitting and part of the wave accumulating at one null and the rest at the other. Current density will then accumulate at these points and ohmic dissipation will then extract the energy in the wave at these points. This suggests locations where wave heating will occur in the corona. The Alfv\\'en wave behaves in a different manner in that the wave accumulates along the separatrices. Hence, the current density will accumulate at this part of the topology and this is where wave heating will occur. However, the phenomenon of wave accumulation at a specific place is a feature of both wave types, and illustrates the importance of studying the topology of the corona when considering MHD wave propagation.

J. A. McLaughlin; A. W. Hood

2007-12-11T23:59:59.000Z

354

PROPAGATING WAVES ALONG SPICULES  

SciTech Connect (OSTI)

Alfvenic waves are thought to play an important role in coronal heating and acceleration of solar wind. Here we investigate the statistical properties of Alfvenic waves along spicules (jets that protrude into the corona) in a polar coronal hole using high-cadence observations of the Solar Optical Telescope on board Hinode. We developed a technique for the automated detection of spicules and high-frequency waves. We detected 89 spicules and found (1) a mix of upward propagating, downward propagating, as well as standing waves (occurrence rates of 59%, 21%, and 20%, respectively); (2) the phase speed gradually increases with height; (3) upward waves dominant at lower altitudes, standing waves at higher altitudes; (4) standing waves dominant in the early and late phases of each spicule, while upward waves were dominant in the middle phase; (5) in some spicules, we find waves propagating upward (from the bottom) and downward (from the top) to form a standing wave in the middle of the spicule; and (6) the medians of the amplitude, period, and velocity amplitude were 55 km, 45 s, and 7.4 km s{sup -1}, respectively. We speculate that upward propagating waves are produced near the solar surface (below the spicule) and downward propagating waves are caused by reflection of (initially) upward propagating waves off the transition region at the spicule top. The mix of upward and downward propagating waves implies that exploiting these waves to perform seismology of the spicular environment requires careful analysis and may be problematic.

Okamoto, Takenori J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); De Pontieu, Bart, E-mail: joten.okamoto@nao.ac.jp [Lockheed Martin Solar and Astrophysics Laboratory, B/252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)

2011-08-01T23:59:59.000Z

355

the wave model A traveling wave is an organized disturbance  

E-Print Network [OSTI]

1 waves the wave model A traveling wave is an organized disturbance propagating at a well-defined wave speed v. · In transverse waves the particles of the medium move perpendicular to the direction of wave propagation. · In longitudinal waves the particles of the medium move parallel to the direction

Winokur, Michael

356

Organized Oscillations of Initially-Turbulent Flow Past a Cavity  

SciTech Connect (OSTI)

Flow past an open cavity is known to give rise to self-sustained oscillations in a wide variety of configurations, including slotted-wall, wind and water tunnels, slotted flumes, bellows-type pipe geometries, high-head gates and gate slots, aircraft components and internal piping systems. These cavity-type oscillations are the origin of coherent and broadband sources of noise and, if the structure is sufficiently flexible, flow-induced vibration as well. Moreover, depending upon the state of the cavity oscillation, substantial alterations of the mean drag may be induced. In the following, the state of knowledge of flow past cavities, based primarily on laminar inflow conditions, is described within a framework based on the flow physics. Then, the major unresolved issues for this class of flows will be delineated. Self-excited cavity oscillations have generic features, which are assessed in detail in the reviews of Rockwell and Naudascher, Rockwell, Howe and Rockwell. These features, which are illustrated in the schematic of Figure 1, are: (i) interaction of a vorticity concentration(s) with the downstream corner, (ii) upstream influence from this corner interaction to the sensitive region of the shear layer formed from the upstream corner of the cavity; (iii) conversion of the upstream influence arriving at this location to a fluctuation in the separating shear layer; and (iv) amplification of this fluctuation in the shear layer as it develops in the streamwise direction. In view of the fact that inflow shear-layer in the present investigation is fully turbulent, item (iv) is of particular interest. It is generally recognized, at least for laminar conditions at separation from the leading-corner of the cavity, that the disturbance growth in the shear layer can be described using concepts of linearized, inviscid stability theory, as shown by Rockwell, Sarohia, and Knisely and Rockwell. As demonstrated by Knisely and Rockwell, on the basis of experiments interpreted with the aid of linearized theory, not only the fundamental component of the shear layer instability may be present, but a number of additional, primarily lower frequency components can exist as well. In fact, the magnitude of these components can be of the same order as the fundamental component. These issues have not been addressed for the case of a fully-turbulent in-flow and its separation from the leading corner of the cavity.

J.C. Lin; D. Rockwell

2002-09-17T23:59:59.000Z

357

Subsonic Free Surface Waves in Linear Elasticity  

E-Print Network [OSTI]

For general anisotropic linear elastic solids with smooth boundaries, Rayleigh-type surface waves are studied. Using spectral factorizations of matrix polynomials, a self-contained exposition of the case of a homogeneous half-space is given first. The main result is about inhomogeneous anisotropic bodies with curved surfaces. The existence of subsonic free surface waves is shown by giving ray series asymptotic expansions, including formulas for the transport equation.

Sönke Hansen

2014-05-09T23:59:59.000Z

358

ARE PULSING SOLITARY WAVES RUNNING INSIDE THE SUN?  

SciTech Connect (OSTI)

A precise sequence of frequencies-detected four independent ways-is interpreted as a system of solitary waves below the Sun's convective envelope. Six future observational or theoretical tests of this idea are suggested. Wave properties (rotation rates, radial energy distribution, nuclear excitation strength) follow from conventional dynamics of global oscillation modes after assuming a localized nuclear term strong enough to perturb and hold mode longitudes into alignments that form 'families'. To facilitate future tests, more details are derived for a system of two dozen solitary waves 2 {<=} l {<=} 25. Wave excitation by {sup 3}He and {sup 14}C burning is complex. It spikes by factors M{sub 1} {<=} 10{sup 3} when many waves overlap in longitude but its long-time average is M{sub 2} {<=} 10. Including mixing can raise overall excitation to {approx}50 times that in a standard solar model. These spikes cause tiny phase shifts that tend to pull wave rotation rates toward their ideal values {proportional_to}[l(l + 1)]{sup -1}. A system like this would generate some extra nuclear energy in two spots at low latitude on opposite sides of the Sun. Each covers about 20 Degree-Sign of longitude. Above a certain wave amplitude, the system starts giving distinctly more nuclear excitation to some waves (e.g., l = 9, 14, and 20) than to neighboring l values. The prominence of l = 20 has already been reported. This transition begins at temperature amplitudes {Delta}T/T = 0.03 in the solar core for a typical family of modes, which corresponds to {delta}T/T {approx} 0.001 for one of its many component oscillation modes.

Wolff, Charles L., E-mail: charles.l.wolff@nasa.gov [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-10T23:59:59.000Z

359

Tests of Lorentz and CPT violation with MiniBooNE neutrino oscillation excesses  

E-Print Network [OSTI]

Violation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck-scale physics. Various types of data are analyzed to search for Lorentz violation under the Standard-Model Extension (SME) framework, including neutrino oscillation data. MiniBooNE is a short-baseline neutrino oscillation experiment at Fermilab. The measured excesses from MiniBooNE cannot be reconciled within the neutrino Standard Model; thus it might be a signal of new physics, such as Lorentz violation. We have analyzed the sidereal time dependence of MiniBooNE data for signals of the possible breakdown of Lorentz invariance in neutrinos. In this brief review, we introduce Lorentz violation, the neutrino sector of the SME, and the analysis of short-baseline neutrino oscillation experiments. We then present the results of the search for Lorentz violation in MiniBooNE data. This review is based on the published result (ArXiv:1109.3480).

Teppei Katori

2014-04-28T23:59:59.000Z

360

Chimera states in systems of nonlocal nonidentical phase-coupled oscillators  

E-Print Network [OSTI]

Chimera states consisting of domains of coherently and incoherently oscillating nonlocally-coupled phase oscillators in systems with spatial inhomogeneity are studied. The inhomogeneity is introduced through the dependence of the oscillator frequency on its location. Two types of spatial inhomogeneity, localized and spatially periodic, are considered and their effects on the existence and properties of multi-cluster and traveling chimera states are explored. The inhomogeneity is found to break up splay states, to pin the chimera states to specific locations and to trap traveling chimeras. Many of these states can be studied by constructing an evolution equation for a complex order parameter. Solutions of this equation are in good agreement with the results of numerical simulations.

Jianbo Xie; Hsien-Ching Kao; Edgar Knobloch

2015-01-02T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Intensity oscillations in the carbon 1s ionization cross sections of 2-butyne  

SciTech Connect (OSTI)

Carbon 1s photoelectron spectra for 2-butyne (CH{sub 3}C{identical_to}CCH{sub 3}) measured in the photon energy range from threshold to 150 eV above threshold show oscillations in the intensity ratio C2,3/C1,4. Similar oscillations have been seen in chloroethanes, where the effect has been attributed to EXAFS-type scattering from the substituent chlorine atoms. In 2-butyne, however, there is no high-Z atom to provide a scattering center and, hence, oscillations of the magnitude observed are surprising. The results have been analyzed in terms of two different theoretical models: a density-functional model with B-spline atom-centered functions to represent the continuum electrons and a multiple-scattering model using muffin-tin potentials to represent the scattering centers. Both methods give a reasonable description of the energy dependence of the intensity ratios.

Carroll, Thomas X. [Division of Natural Sciences, Keuka College, Keuka Park, New York 14478 (United States); Zahl, Maria G.; Borve, Knut J.; Saethre, Leif J. [Department of Chemistry, University of Bergen, Allegaten 41, NO-5007 Bergen (Norway); Decleva, Piero; Ponzi, Aurora [Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste (Italy); Kas, Joshua J.; Vila, Fernando D.; Rehr, John J. [Department of Physics, University of Washington, Box 351560, Seattle, Washington 98195-1560 (United States); Thomas, T. Darrah [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)

2013-06-21T23:59:59.000Z

362

Oscillations During Thermonuclear X-ray Bursts: A New Probe of Neutron Stars  

E-Print Network [OSTI]

Observations of thermonuclear (Type I) X-ray bursts from neutron stars in low mass X-ray binaries (LMXB) with the Rossi X-ray Timing Explorer (RXTE) have revealed large amplitude, high coherence X-ray brightness oscillations with frequencies in the 300 - 600 Hz range. Substantial spectral and timing evidence point to rotational modulation of the X-ray burst flux as the cause of these oscillations, and it is likely that they reveal the spin frequencies of neutron stars in LMXB from which they are detected. Here I review the status of our knowledge of these oscillations and describe how they can be used to constrain the masses and radii of neutron stars as well as the physics of thermonuclear burning on accreting neutron stars.

Tod E. Strohmayer

1999-11-19T23:59:59.000Z

363

Nonequilibrium free energy, H theorem and self-sustained oscillations for Boltzmann-BGK descriptions of semiconductor superlattices  

E-Print Network [OSTI]

Semiconductor superlattices (SL) may be described by a Boltzmann-Poisson kinetic equation with a Bhatnagar-Gross-Krook (BGK) collision term which preserves charge, but not momentum or energy. Under appropriate boundary and voltage bias conditions, these equations exhibit time-periodic oscillations of the current caused by repeated nucleation and motion of charge dipole waves. Despite this clear nonequilibrium behavior, if we `close' the system by attaching insulated contacts to the superlattice and keeping its voltage bias to zero volts, we can prove the H theorem, namely that a free energy $\\Phi(t)$ of the kinetic equations is a Lyapunov functional ($\\Phi\\geq 0$, $d\\Phi/dt\\leq 0$). Numerical simulations confirm that the free energy decays to its equilibrium value for a closed SL, whereas for an `open' SL under appropriate dc voltage bias and contact conductivity $\\Phi(t)$ oscillates in time with the same frequency as the current self-sustained oscillations.

M Alvaro; L L Bonilla

2010-12-14T23:59:59.000Z

364

Kinematic Density Waves in Accretion Disks  

E-Print Network [OSTI]

When thin accretion disks around black holes are perturbed, the main restoring force is gravity. If gas pressure, magnetic stresses, and radiation pressure are neglected, the disk remains thin as long as orbits do not intersect. Intersections would result in pressure forces which limit the growth of perturbations. We find that a discrete set of perturbations is possible for which orbits remain non-intersecting for arbitrarily long times. These modes define a discrete set of frequencies. We classify all long-lived perturbations for arbitrary potentials and show how their mode frequencies are related to pattern speeds computed from the azimuthal and epicyclic frequencies. We show that modes are concentrated near radii where the pattern speed has vanishing radial derivative. We explore these modes around Kerr black holes as a possible explanation for the high-frequency quasi-periodic oscillations of black hole binaries such as GRO J1655-40. The long-lived modes are shown to coincide with diskoseismic waves in the limit of small sound speed. While the waves have long lifetime, they have the wrong frequencies to explain the pairs of high-frequency quasi-periodic oscillations observed in black hole binaries.

Svetlin Tassev; Edmund Bertschinger

2008-10-14T23:59:59.000Z

365

Coupled Oscillator Systems Having Partial PT Symmetry  

E-Print Network [OSTI]

This paper examines chains of $N$ coupled harmonic oscillators. In isolation, the $j$th oscillator ($1\\leq j\\leq N$) has the natural frequency $\\omega_j$ and is described by the Hamiltonian $\\frac{1}{2}p_j^2+\\frac{1}{2}\\omega_j^2x_j^2$. The oscillators are coupled adjacently with coupling constants that are purely imaginary; the coupling of the $j$th oscillator to the $(j+1)$st oscillator has the bilinear form $i\\gamma x_jx_{j+1}$ ($\\gamma$ real). The complex Hamiltonians for these systems exhibit {\\it partial} $\\mathcal{PT}$ symmetry; that is, they are invariant under $i\\to-i$ (time reversal), $x_j\\to-x_j$ ($j$ odd), and $x_j\\to x_j$ ($j$ even). [They are also invariant under $i\\to-i$, $x_j\\to x_j$ ($j$ odd), and $x_j\\to- x_j$ ($j$ even).] For all $N$ the quantum energy levels of these systems are calculated exactly and it is shown that the ground-state energy is real. When $\\omega_j=1$ for all $j$, the full spectrum consists of a real energy spectrum embedded in a complex one; the eigenfunctions correspondi...

Beygi, Alireza; Bender, Carl M

2015-01-01T23:59:59.000Z

366

Phase-mixing of Langmuir oscillations in cold electron-positron-ion plasmas  

SciTech Connect (OSTI)

Space-time evolution of Langmuir oscillations in a cold homogeneous electron-positron-ion plasma has been analyzed by employing a straightforward perturbation expansion method, showing phase-mixing and, thus, wave-breaking of excited oscillations at arbitrary amplitudes. Within an assumption of infinitely massive ions, an approximate phase-mixing time is found to scale as ?{sub pe}t{sub mix}?[(6/?{sup 2})((2??){sup 5/2}/(1??))]{sup 1/3}, where “?” and “?” (= n{sub 0i}/n{sub 0e}) are the amplitude of perturbation and the ratio of equilibrium ion density to equilibrium electron density, respectively, and ?{sub pe}??(4?n{sub 0e}e{sup 2}/m) is the electron plasma frequency. The results presented on phase-mixing of Langmuir modes in multispecies plasmas are expected to be relevant to laboratory and astrophysical environments.

Maity, Chandan [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

2014-07-15T23:59:59.000Z

367

Sub-structure of laser generated harmonics reveals plasma dynamics of a relativistically oscillating mirror  

SciTech Connect (OSTI)

Theoretical and experimental investigations of the dynamics of a relativistically oscillating plasma slab reveal spectral line splitting in laser driven harmonic spectra, leading to double harmonic series. Both series are well characterized with harmonics arising by two fundamental frequencies. While a relativistic oscillation of the critical density drives the harmonic emission, the splitting is a result of an additional acceleration during the laser pulse duration. In comparison with the oscillatory movement, this acceleration is rather weak and can be described by a plasma shock wave driven by the pressure of light. We introduce particle in cell simulations and an analytical model explaining the harmonic line splitting. The derived analytical formula gives direct access between the splitting in the harmonic spectrum and the acceleration of the plasma surface.

Braenzel, J.; Schnürer, M.; Steinke, S.; Priebe, G.; Sandner, W. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany)] [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany); Andreev, A. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany) [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany); Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg (Russian Federation); Platonov, K. [Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg (Russian Federation)] [Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg (Russian Federation)

2013-08-15T23:59:59.000Z

368

Numerical analysis of the coherent radiation emission by two stacked Josephson flux-flow oscillators  

SciTech Connect (OSTI)

The numerical investigation of the radiation emission by a system of two magnetically coupled, long Josephson junctions is reported. Time-dependent synchronized voltage response in the flux-flow regime is analyzed for the case of in-phase and out-of-phase oscillations in the junctions. Simulations show that Josephson junctions operating in the in-phase flux-flow mode may generate rf radiation power by a factor of more than 4 larger than that of a single Josephson junction. The radiation in the out-of-phase flux-flow mode is characterized by nearly completely suppressed amplitudes of odd harmonics and considerably damped even harmonics as compared to that of a single barrier junction. The dependence of the radiation power on the parameter spread between the junctions is investigated. The advantages of using stacked Josephson junctions as oscillators for the sub-mm wave band are discussed. {copyright} {ital 1996 American Institute of Physics.}

Wallraff, A.; Goldobin, E.; Ustinov, A.V. [Institute of Thin Film and Ion Technology, Research Center Juelich (KFA), D-52425 (Germany)] [Institute of Thin Film and Ion Technology, Research Center Juelich (KFA), D-52425 (Germany)

1996-12-01T23:59:59.000Z

369

Two-dimensional water waves in the presence of a freely floating body: conditions for the absence of trapped modes  

E-Print Network [OSTI]

The coupled motion is investigated for a mechanical system consisting of water and a body freely floating in it. Water occupies either a half-space or a layer of constant depth into which an infinitely long surface-piercing cylinder is immersed, thus allowing us to study two-dimensional modes. Under the assumption that the motion is of small amplitude near equilibrium, a linear setting is applicable and for the time-harmonic oscillations it reduces to a spectral problem with the frequency of oscillations as the spectral parameter. It is essential that one of the problem's relations is linear with respect to the parameter, whereas two others are quadratic with respect to it. Within this framework, it is shown that the total energy of the water motion is finite and the equipartition of energy holds for the whole system. On this basis, it is proved that no wave modes can be trapped provided their frequencies exceed a bound depending on cylinder's properties, whereas its geometry is subject to some restrictions and, in some cases, certain restrictions are imposed on the type of mode.

Nikolay Kuznetsov

2015-03-07T23:59:59.000Z

370

Synthetic observations of wave propagation in a sunspot umbra  

E-Print Network [OSTI]

Spectropolarimetric temporal series from Fe I $\\lambda$ 6301.5 \\AA\\ and Ca II infrared triplet lines are obtained by applying the Stokes synthesis code NICOLE to a numerical simulation of wave propagation in a sunspot umbra from MANCHA code. The analysis of the phase difference between Doppler velocity and intensity core oscillations of the Fe I $\\lambda$ 6301.5 \\AA\\ line reveals that variations in the intensity are produced by opacity fluctuations rather than intrinsic temperature oscillations, except for frequencies between 5 and 6.5 mHz. On the other hand, the photospheric magnetic field retrieved from the weak field approximation provides the intrinsic magnetic field oscillations associated to wave propagation. Our results suggest that this is due to the low magnetic field gradient of our sunspot model. The Stokes parameters of the chromospheric Ca II infrared triplet lines show striking variations as shock waves travel through the formation height of the lines, including emission self-reversals in the li...

Felipe, T; Khomenko, E

2014-01-01T23:59:59.000Z

371

Photon wave function  

E-Print Network [OSTI]

Photon wave function is a controversial concept. Controversies stem from the fact that photon wave functions can not have all the properties of the Schroedinger wave functions of nonrelativistic wave mechanics. Insistence on those properties that, owing to peculiarities of photon dynamics, cannot be rendered, led some physicists to the extreme opinion that the photon wave function does not exist. I reject such a fundamentalist point of view in favor of a more pragmatic approach. In my view, the photon wave function exists as long as it can be precisely defined and made useful.

Iwo Bialynicki-Birula

2005-08-26T23:59:59.000Z

372

Phenomena of oscillations in atmospheric pressure direct current glow discharges  

SciTech Connect (OSTI)

Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transform spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.

Liu, Fu-cheng [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)] [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Yan, Wen; Wang, De-zhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-12-15T23:59:59.000Z

373

Generation of high power sub-terahertz radiation from a gyrotron with second harmonic oscillation  

SciTech Connect (OSTI)

New power records of second harmonic gyrotron oscillation have been demonstrated in the sub-THz band. The first step gyrotron of demountable type had succeeded in oscillation with power more than 50 kW at 350 GHz and nearly 40 kW at 390 GHz [T. Notake et al., Phys. Rev. Lett. 103, 225002 (2009)]. Then, the second step gyrotron of sealed-off type was manufactured. A cavity mode was carefully selected to avoid mode competition with a neighboring fundamental harmonic mode. Matching of the selected mode with the electron gun was also circumspectly considered. The second step gyrotron has attained higher power radiation than the first gyrotron. The maximum single mode power was 62 kW at 388 GHz. Then, the electron gun was modified for use of a different cavity mode with a higher coupling coefficient than that for the 62 kW mode. The new mode proved single mode oscillation power of 83 kW at about 389 GHz. These results are new second-harmonic-oscillation power records for sub-THz gyrotrons. The present study constitutes foundations of development of high power second harmonic sub-THz gyrotron for application to collective Thomson scattering measurement on fusion plasmas, especially on high-density plasmas such as those produced in LHD [N. Ohyabu et al., Phys. Rev. Lett. 97, 055002 (2006)]. This paper reports the design consideration to realize high power single mode gyrotron oscillation at second harmonic and the examination of oscillation characteristics of the gyrotron.

Saito, Teruo; Yamada, Naoki; Ikeuti, Shinji; Tatematsu, Yoshinori; Ikeda, Ryosuke; Ogawa, Isamu; Idehara, Toshitaka [Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507 (Japan); Ogasawara, Shinya [Department of Energy Engineering and Science, Nagoya University, Nagoya 464-8463 (Japan); Manuilov, Vladimir N. [Nizhny Novgorod State University, Nizhny Novgorod 603600 (Russian Federation); Shimozuma, Takashi; Kubo, Shin; Nishiura, Masaki; Tanaka, Kenji; Kawahata, Kazuo [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)

2012-06-15T23:59:59.000Z

374

WindWaveFloat Final Report  

SciTech Connect (OSTI)

Principle Power Inc. and National Renewable Energy Lab (NREL) have completed a contract to assess the technical and economic feasibility of integrating wave energy converters into the WindFloat, resulting in a new concept called the WindWaveFloat (WWF). The concentration of several devices on one platform could offer a potential for both economic and operational advantages. Wind and wave energy converters can share the electrical cable and power transfer equipment to transport the electricity to shore. Access to multiple generation devices could be simplified, resulting in cost saving at the operational level. Overall capital costs may also be reduced, provided that the design of the foundation can be adapted to multiple devices with minimum modifications. Finally, the WindWaveFloat confers the ability to increase energy production from individual floating support structures, potentially leading to a reduction in levelized energy costs, an increase in the overall capacity factor, and greater stability of the electrical power delivered to the grid. The research conducted under this grant investigated the integration of several wave energy device types into the WindFloat platform. Several of the resulting system designs demonstrated technical feasibility, but the size and design constraints of the wave energy converters (technical and economic) make the WindWaveFloat concept economically unfeasible at this time. Not enough additional generation could be produced to make the additional expense associated with wave energy conversion integration into the WindFloat worthwhile.

Alla Weinstein, Dominique Roddier, Kevin Banister

2012-03-30T23:59:59.000Z

375

Timescales of Kozai-Lidov oscillations at quadrupole and octupole order in the test particle limit  

E-Print Network [OSTI]

Kozai-Lidov (KL) oscillations in hierarchical triple systems have found application to many astrophysical contexts, including planet formation, type Ia supernovae, and supermassive black hole dynamics. The period of these oscillations is known at the order-of-magnitude level, but dependences on the initial mutual inclination or inner eccentricity are not typically included. In this work I calculate the period of KL oscillations ($t_{\\textrm{KL}}$) exactly in the test particle limit at quadrupole order (TPQ). I explore the parameter space of all hierarchical triples at TPQ and show that except for triples on the boundary between libration and rotation, the period of KL oscillations does not vary by more than a factor of a few. The exact period may be approximated to better than 2 per cent for triples with mutual inclinations between 60$^{\\circ}$ and 120$^{\\circ}$ and initial eccentricities less than $\\sim$0.3. In addition, I derive an analytic expression for the period of octupole-order oscillations due to the...

Antognini, Joseph M O

2015-01-01T23:59:59.000Z

376

Direct simulation and deterministic prediction of large-scale nonlinear ocean wave-field  

E-Print Network [OSTI]

Despite its coarse approximation of physics, the phase-averaged wave spectrum model has been the only type of tool available for ocean wave prediction in the past 60 years. With the rapid advances in sensing technology, ...

Wu, Guangyu, 1972-

2004-01-01T23:59:59.000Z

377

E-Print Network 3.0 - anomalous spin waves Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

superconductor possesses propagating, spin-wave type... the spin-mediated d-wave superconduct- ing gap is at maximum. If the voltage for SIN tunneling... emit a propagating spin...

378

Magnetohydrodynamics wave propagation in the neighbourhood of two dipoles  

E-Print Network [OSTI]

This paper is the third in a series of investigations by the authors. The nature of fast magnetoacoustic and Alfv\\'en waves is investigated in a 2D $\\beta=0$ plasma in the neighbourhood of two dipoles. We use both numerical simulations (two-step Lax-Wendroff scheme) and analytical techniques (WKB approximation). It is found that the propagation of the linear fast wave is dictated by the Alfv\\'en speed profile and that close to the null, the wave is attracted to the neutral point. However, it is also found that in this magnetic configuration some of the wave can escape the refraction effect; this had not been seen in previous investigations by the authors. The wave split occurs near the regions of very high Alfv\\'en speed (found near the loci of the two dipoles). Also, for the set-up investigated it was found that 40% of the wave energy accumulates at the null. Ohmic dissipation will then extract the wave energy at this point. The Alfv\\'en wave behaves in a different manner in that part of the wave accumulates along the separatrices and part escapes. Hence, the current density will accumulate at this part of the topology and this is where wave heating will occur. The phenomenon of wave accumulation at a specific place is a feature of both wave types, as is the result that a fraction of the wave can now escape the numerical box when propagating in this magnetic configuration.

J. A. McLaughlin; A. W. Hood

2007-12-11T23:59:59.000Z

379

Rogue Wave Modes for the Long Wave-Short Wave Resonance Kwok Wing CHOW*(1)  

E-Print Network [OSTI]

1 Rogue Wave Modes for the Long Wave-Short Wave Resonance Model Kwok Wing CHOW*(1) , Hiu Ning CHAN.45.Yv; 47.35.Fg ABSTRACT The long wave-short wave resonance model arises physically when the phase velocity of a long wave matches the group velocity of a short wave. It is a system of nonlinear evolution

380

MiniBooNE Oscillation Results 2011  

SciTech Connect (OSTI)

The MiniBooNE neutrino oscillation search experiment at Fermilab has recently updated results from a search for {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations, using a data sample corresponding to 8.58 x 10{sup 20} protons on target in anti-neutrino mode. This high statistics result represent an increase in statistics of 52% compared to result published in 2010. An excess of 57.7 {+-} 28.5 events is observed in the energy range 200 MeV < E{sub {nu}} < 3000 MeV. The data favor LSND-like {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations over a background only hypothesis at 91.1% confidence level in the energy range 475 < E{sub {nu}} < 3000 MeV.

Djurcic, Zelimir

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Non-linear and quantum optics of a type II OPO containing a birefringent element Part 1: Classical operation  

E-Print Network [OSTI]

We describe theoretically the main characteristics of the steady state regime of a type II Optical Parametric Oscillator (OPO) containing a birefringent plate. In such a device the signal and idler waves are at the same time linearly coupled by the plate and nonlinearly coupled by the $\\chi^{(2)}$ crystal. This mixed coupling allows, in some well-defined range of the control parameters, a frequency degenerate operation as well as phase locking between the signal and idler modes. We describe here a complete model taking into account all possible effects in the system, \\emph{i.e.} arbitrary rotation of the waveplate, non perfect phase matching, ring and linear cavities. This model is able to explain the detailed features of the experiments performed with this system.

Laurent Longchambon; Julien Laurat; Thomas Coudreau; Claude Fabre

2003-10-06T23:59:59.000Z

382

IMPLICATIONS OF BURST OSCILLATIONS FROM THE SLOWLY ROTATING ACCRETING PULSAR IGR J17480-2446 IN THE GLOBULAR CLUSTER TERZAN 5  

SciTech Connect (OSTI)

The recently discovered accreting X-ray pulsar IGR J17480-2446 spins at a frequency of {approx}11 Hz. We show that Type I X-ray bursts from this source display oscillations at the same frequency as the stellar spin. IGR J17480-2446 is the first secure case of a slowly rotating neutron star (NS) which shows Type I burst oscillations (BOs), all other sources featuring such oscillations spin at hundreds of Hertz. This means that we can test BO models in a completely different regime. We explore the origin of Type I BOs in IGR J17480-2446 and conclude that they are not caused by global modes in the NS ocean. We also show that the Coriolis force is not able to confine an oscillation-producing hot spot on the stellar surface. The most likely scenario is that the BOs are produced by a hot spot confined by hydromagnetic stresses.

Cavecchi, Y.; Patruno, A.; Haskell, B.; Watts, A. L.; Altamirano, D.; Wijnands, R.; Van der Klis, M. [Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Levin, Y. [Sterrewacht Leiden, University of Leiden, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands); Linares, M., E-mail: Y.Cavecchi@uva.nl [MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States)

2011-10-10T23:59:59.000Z

383

Frequency stabilization in nonlinear MEMS and NEMS oscillators  

DOE Patents [OSTI]

An illustrative system includes an amplifier operably connected to a phase shifter. The amplifier is configured to amplify a voltage from an oscillator. The phase shifter is operably connected to a driving amplitude control, wherein the phase shifter is configured to phase shift the amplified voltage and is configured to set an amplitude of the phase shifted voltage. The oscillator is operably connected to the driving amplitude control. The phase shifted voltage drives the oscillator. The oscillator is at an internal resonance condition, based at least on the amplitude of the phase shifted voltage, that stabilizes frequency oscillations in the oscillator.

Lopez, Omar Daniel; Antonio, Dario

2014-09-16T23:59:59.000Z

384

New wave generation  

E-Print Network [OSTI]

We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (Exp. Fluids, vol. 42, 2007, pp. 123–130). This ...

Mercier, Matthieu J.

385

Faceting oscillations in nano-ferroelectrics  

SciTech Connect (OSTI)

We observe periodic faceting of 8-nm diameter ferroelectric disks on a 10?s time-scale when thin Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} film is exposed to constant high-resolution transmission electron microscopy beams. The oscillation is between circular disk geometry and sharply faceted hexagons. The behavior is analogous to that of spin structure and magnetic domain wall velocity oscillations in permalloy [Bisig et al., Nat. Commun. 4, 2328 (2013)], involving overshoot and de-pinning from defects [Amann et al., J. Rheol. 57, 149–175 (2013)].

Scott, J. F., E-mail: jfs32@cam.ac.uk, E-mail: ashok553@nplindia.org [Cavendish Laboratory, Cambridge University, Cambridge (United Kingdom); Kumar, Ashok, E-mail: jfs32@cam.ac.uk, E-mail: ashok553@nplindia.org [CSIR-National Physical Laboratory, Delhi (India)

2014-08-04T23:59:59.000Z

386

Harmonic-Oscillator-Based Effective Theory  

E-Print Network [OSTI]

I describe harmonic-oscillator-based effective theory (HOBET) and explore the extent to which the effects of excluded higher-energy oscillator shells can be represented by a contact-gradient expansion in next-to-next-to-leading order (NNLO). I find the expansion can be very successful provided the energy dependence of the effective interaction, connected with missing long-wavelength physics associated with low-energy breakup channels, is taken into account. I discuss a modification that removes operator mixing from HOBET, simplifying the task of determining the parameters of an NNLO interaction.

W. C. Haxton

2006-08-06T23:59:59.000Z

387

The oscillating two-cluster chimera state in non-locally coupled phase oscillators  

E-Print Network [OSTI]

We investigate an array of identical phase oscillators non-locally coupled without time delay, and find that chimera state with two coherent clusters exists which is only reported in delay-coupled systems previously. Moreover, we find that the chimera state is not stationary for any finite number of oscillators. The existence of the two-cluster chimera state and its time-dependent behaviors for finite number of oscillators are confirmed by the theoretical analysis based on the self-consistency treatment and the Ott-Antonsen ansatz.

Yun Zhu; Yuting Li; Mei Zhang; Junzhong Yang

2011-09-20T23:59:59.000Z

388

Performance Assessment of the Wave Dragon Wave Energy Converter  

E-Print Network [OSTI]

Performance Assessment of the Wave Dragon Wave Energy Converter Based on the EquiMar Methodology S of the wave energy sector, device developers are called to provide reliable estimates on power performanceMar, Nissum Bredning, Hanstholm, North Sea, Ekofisk, Wave-to-wire, Wave energy. I. INTRODUCTION The wave

Hansen, René Rydhof

389

Theory versus experiment for vacuum Rabi oscillations in lossy cavities. II. Direct test of uniqueness of vacuum  

SciTech Connect (OSTI)

The paper continues the analysis of vacuum Rabi oscillations we started in part I [Phys. Rev. A 79, 033836 (2009)]. Here we concentrate on experimental consequences for cavity QED of two different classes of representations of harmonic-oscillator Lie algebras. The zero-temperature master equation, derived in part I for irreducible representations of the algebra, is reformulated in a reducible representation that models electromagnetic fields by a gas of harmonic-oscillator wave packets. The representation is known to introduce automatic regularizations that in irreducible representations would have to be justified by ad hoc arguments. Predictions based on this representation are characterized in thermodynamic limit by a single parameter {sigma}, responsible for collapses and revivals of Rabi oscillations in exact vacuum. Collapses and revivals disappear in the limit {sigma}{yields}{infinity}. Observation of a finite {sigma} would mean that cavity quantum fields are described by a non-Wightmanian theory, where vacuum states are zero-temperature Bose-Einstein condensates of a N-particle bosonic oscillator gas and, thus, are nonunique. The data collected in the experiment of Brune et al. [Phys. Rev. Lett. 76, 1800 (1996)] are consistent with any {sigma}>400.

Wilczewski, Marcin; Czachor, Marek [Katedra Fizyki Teoretycznej i Informatyki Kwantowej, Politechnika Gdanska, 80-952 Gdansk (Poland); Krajowe Centrum Informatyki Kwantowej, 81-824 Sopot (Poland) and Centrum Leo Apostel (CLEA), Vrije Universiteit Brussel, 1050 Brussels (Belgium)

2009-07-15T23:59:59.000Z

390

Theory versus experiment for vacuum Rabi oscillations in lossy cavities (II): Direct test of uniqueness of vacuum  

E-Print Network [OSTI]

The paper continues the analysis of vacuum Rabi oscillations we started in Part I [Phys. Rev. A {\\bf 79}, 033836 (2009)]. Here we concentrate on experimental consequences for cavity QED of two different classes of representations of harmonic oscillator Lie algebras. The zero-temperature master equation, derived in Part I for irreducible representations of the algebra, is reformulated in a reducible representation that models electromagnetic fields by a gas of harmonic oscillator wave packets. The representation is known to introduce automatic regularizations that in irreducible representations would have to be justified by ad hoc arguments. Predictions based on this representation are characterized in thermodynamic limit by a single parameter $\\varsigma$, responsible for collapses and revivals of Rabi oscillations in exact vacuum. Collapses and revivals disappear in the limit $\\varsigma\\to\\infty$. Observation of a finite $\\varsigma$ would mean that cavity quantum fields are described by a non-Wightmanian theory, where vacuum states are zero-temperature Bose-Einstein condensates of a finite-particle bosonic oscillator gas and, thus, are non-unique. The data collected in the experiment of Brune {\\it et al.} [Phys. Rev. Lett. {\\bf{76}}, 1800 (1996)] are consistent with any $\\varsigma>400$.

Marcin Wilczewski; Marek Czachor

2009-05-28T23:59:59.000Z

391

SLOW MAGNETOSONIC WAVES AND FAST FLOWS IN ACTIVE REGION LOOPS  

SciTech Connect (OSTI)

Recent extreme ultraviolet spectroscopic observations indicate that slow magnetosonic waves are present in active region (AR) loops. Some of the spectral data were also interpreted as evidence of fast ({approx}100-300 km s{sup -1}) quasi-periodic flows. We have performed three-dimensional magnetohydrodynamic (3D MHD) modeling of a bipolar AR that contains impulsively generated waves and flows in coronal loops. The model AR is initiated with a dipole magnetic field and gravitationally stratified density, with an upflow-driven steadily or periodically in localized regions at the footpoints of magnetic loops. The resulting flows along the magnetic field lines of the AR produce higher density loops compared to the surrounding plasma by injection of material into the flux tubes and the establishment of siphon flow. We find that the impulsive onset of flows with subsonic speeds result in the excitation of damped slow magnetosonic waves that propagate along the loops and coupled nonlinearly driven fast-mode waves. The phase speed of the slow magnetosonic waves is close to the coronal sound speed. When the amplitude of the driving pulses is increased we find that slow shock-like wave trains are produced. When the upflows are driven periodically, undamped oscillations are produced with periods determined by the periodicity of the upflows. Based on the results of the 3D MHD model we suggest that the observed slow magnetosonic waves and persistent upflows may be produced by the same impulsive events at the bases of ARs.

Ofman, L.; Wang, T. J. [Department of Physics, Catholic University of America, Washington, DC 20064 (United States); Davila, J. M. [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States)

2012-08-01T23:59:59.000Z

392

Autoresonant excitation and evolution of nonlinear waves: The variational approach L. Friedland  

E-Print Network [OSTI]

evolves by being phase locked with the pump wave in an extended region of space and/or time despite the variation of system's parameters. This automatic phase locking autoresonance yields a possibility of shaping known as a persisting phase lock- ing between resonantly driven nonlinear oscillators and driv- ing

Friedland, Lazar

393

Wave turbulence and Bose-Einstein condensates Fluctuations turbulentes dans les condensats de Bose-Einstein  

E-Print Network [OSTI]

Wave turbulence and Bose-Einstein condensates Fluctuations turbulentes dans les condensats de Bose-Einstein condensates are considered. A statistical approach is presented following[1] to describe the stationary regime shows rapid oscillation of the condensate. R#19;esum#19;e Le comportement asymptotique des

394

Mammalian Spontaneous Otoacoustic Emissions are Amplitude-Stabilized Cochlear Standing Waves  

E-Print Network [OSTI]

in middle-ear impedance 17 IV Are the Standing Waves Powered by Noise? 19 A Generalization of the Bialek with "certain cells" or parts of cells (e.g., hair-cell stereocilia or somatic motor proteins) within the organ of sound from the ear. Normally, the low-amplitude vibration of the self-tuned critical oscillators would

Allen, Jont

395

Investigation and Construction of Self-oscillating Systems  

E-Print Network [OSTI]

Self-oscillating reactions have been widely observed and studied since the last century because they exhibit unique behaviors different from the traditional chemical reactions. Self-oscillating systems, such as the Belousov-Zhabotinsky (BZ) reaction...

Wang, Guanqun

2012-07-16T23:59:59.000Z

396

Title of dissertation: SYNCHRONIZATION OF CHAOTIC OPTOELECTRONIC OSCILLATORS  

E-Print Network [OSTI]

ABSTRACT Title of dissertation: SYNCHRONIZATION OF CHAOTIC OPTOELECTRONIC OSCILLATORS: ADAPTIVE channels. Here, using a fiber-optic network of chaotic optoelectronic oscillators, we experimentally on synchronization. Through measurements of the convergence rate to synchronization in networks of optoelectronic

Anlage, Steven

397

Striatal origin of the pathologic beta oscillations in Parkinson's disease  

E-Print Network [OSTI]

Enhanced oscillations at beta frequencies (8–30 Hz) are a signature neural dynamic pathology in the basal ganglia and cortex of Parkinson's disease patients. The mechanisms underlying these pathological beta oscillations ...

Boyden, Edward Stuart

398

Combining Genetic Oscillators and Switches using Evolutionary Algorithms  

E-Print Network [OSTI]

motifs, one toggle switch and one self- sustained oscillator using an evolutionary algorithm, which can]. Of particular interest in biology are those network motifs that produce self-sustained oscillations and bistable

Jin, Yaochu

399

Van der Pol and the history of relaxation oscillations  

E-Print Network [OSTI]

by self-sustained oscillating systems such as a triode circuit. Our aim is to investigate how re- laxation to be experi- mentally observed. Among systems able to present self-sustained oscillations and which were

Boyer, Edmond

400

Maximum entropy method and oscillations in the diffraction cone  

E-Print Network [OSTI]

The maximum entropy method has been applied to investigate the oscillating structure in the pbarp- and pp-elastic scattering differential cross-section at high energy and small momentum transfer. Oscillations satisfying quite realistic reliability criteria have been found.

O. Dumbrajs; J. Kontros; A. Lengyel

2000-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

ARM Madden-Julian Oscillation Investigation Experiment  

ScienceCinema (OSTI)

Results of the ARM Madden-Julian Oscillation (MJO) Investigation Experiment (AMIE) field campaign are contributing significantly to concurrent national and international research efforts addressing questions about how the MJO initiates and changes as it passes phenomenon differs in observations versus models.

Long, Chuck

2014-06-13T23:59:59.000Z

402

High frequency inductive lamp and power oscillator  

DOE Patents [OSTI]

An oscillator includes an amplifier having an input and an output, a feedback network connected between the input of the amplifier and the output of the amplifier, the feedback network being configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and a tuning circuit connected to the input of the amplifier, wherein the tuning circuit is continuously variable and consists of solid state electrical components with no mechanically adjustable devices including a pair of diodes connected to each other at their respective cathodes with a control voltage connected at the junction of the diodes. Another oscillator includes an amplifier having an input and an output, a feedback network connected between the input of the amplifier and the output of the amplifier, the feedback network being configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and transmission lines connected to the input of the amplifier with an input pad and a perpendicular transmission line extending from the input pad and forming a leg of a resonant "T", and wherein the feedback network is coupled to the leg of the resonant "T".

Kirkpatrick, Douglas A.; Gitsevich, Aleksandr

2005-09-27T23:59:59.000Z

403

ARITHMETIC OF THE OSCILLATOR REPRESENTATION Michael Harris  

E-Print Network [OSTI]

ARITHMETIC OF THE OSCILLATOR REPRESENTATION Michael Harris §1. Moduli 1.1. Let V = Q2g , and let schemes g N : Ag N [N] - (N-1 T/T)Mg N . Typeset by AMS-TEX 1 #12;2 MICHAEL HARRIS 1.3. Let : Ag N Mg N

Harris, Michael - Institut de Mathématiques de Jussieu, Université Paris 7

404

ARM Madden-Julian Oscillation Investigation Experiment  

SciTech Connect (OSTI)

Results of the ARM Madden-Julian Oscillation (MJO) Investigation Experiment (AMIE) field campaign are contributing significantly to concurrent national and international research efforts addressing questions about how the MJO initiates and changes as it passes phenomenon differs in observations versus models.

Long, Chuck

2014-03-29T23:59:59.000Z

405

Neutrino oscillations and neutrinoless double beta decay  

E-Print Network [OSTI]

The relation between neutrino oscillation parameters and neutrinoless double beta decay is studied, assuming normal and inverse hierarchies for Majorana neutrino masses. For normal hierarchy the crucial dependence on U_{e3} is explored. The link with tritium beta decay is also briefly discussed.

D. Falcone; F. Tramontano

2001-03-16T23:59:59.000Z

406

Accelerator-based neutrino oscillation experiments  

SciTech Connect (OSTI)

Neutrino oscillations were first discovered by experiments looking at neutrinos coming from extra-terrestrial sources, namely the sun and the atmosphere, but we will be depending on earth-based sources to take many of the next steps in this field. This article describes what has been learned so far from accelerator-based neutrino oscillation experiments, and then describe very generally what the next accelerator-based steps are. In section 2 the article discusses how one uses an accelerator to make a neutrino beam, in particular, one made from decays in flight of charged pions. There are several different neutrino detection methods currently in use, or under development. In section 3 these are presented, with a description of the general concept, an example of such a detector, and then a brief discussion of the outstanding issues associated with this detection technique. Finally, section 4 describes how the measurements of oscillation probabilities are made. This includes a description of the near detector technique and how it can be used to make the most precise measurements of neutrino oscillations.

Harris, Deborah A.; /Fermilab

2007-12-01T23:59:59.000Z

407

Improved Theory of Neutrino Oscillations in Matter  

E-Print Network [OSTI]

This is revision of the S-Matrix theory of neutrino oscillations used for many years. We evaluate the transition probability of a $\\mu$ to $e$ neutrino without an approximation used for many theoretical studies, and find important differences which could improve the extraction of neutrino parameters from experimental data in the future.

Leonard S. Kisslinger

2014-11-19T23:59:59.000Z

408

Analysis of sawtooth relaxation oscillations in tokamaks  

SciTech Connect (OSTI)

Sawtooth relaxation oscillations are analyzed using the Kadomtsev's disruption model and a thermal relaxation model. The sawtooth period is found to be very sensitive to the thermal conduction loss. Qualitative agreement between these calculations and the sawtooth period observed in several tokamaks is demonstrated.

Yamazaki, K.; McGuire, K.; Okabayashi, M.

1982-07-01T23:59:59.000Z

409

Oscillation control system for electric motor drive  

DOE Patents [OSTI]

A feedback system for controlling mechanical oscillations in the torsionally complaint drive train of an electric or other vehicle. Motor speed is converted in a processor to estimate state signals in which a plant model which are used to electronically modify thetorque commands applied to the motor.

Slicker, James M. (Union Lake, MI); Sereshteh, Ahmad (Union Lake, MI)

1988-01-01T23:59:59.000Z

410

Oscillation control system for electric motor drive  

DOE Patents [OSTI]

A feedback system for controlling mechanical oscillations in the torsionally complaint drive train of an electric or other vehicle. Motor speed is converted in a processor to estimate state signals in which a plant model which are used to electronically modify the torque commands applied to the motor. 5 figs.

Slicker, J.M.; Sereshteh, A.

1988-08-30T23:59:59.000Z

411

Neutrino mixing and oscillations in astrophysical environments  

SciTech Connect (OSTI)

A brief review of the current status of neutrino mixing and oscillations in astrophysical environments, with particular emphasis on the Sun and core-collapse supernovae, is given. Implications of the existence of sterile states which mix with the active neutrinos are discussed.

Balantekin, A. B. [Physics Department, University of Wisconsin, Madison WI 53706 (United States)

2014-05-02T23:59:59.000Z

412

Wave Energy Converter Effects on Wave Fields: Evaluation of SNL-SWAN and Sensitivity Studies in Monterey Bay CA.  

SciTech Connect (OSTI)

A modified version of an indust ry standard wave modeling tool was evaluated, optimized, and utilized to investigate model sensitivity to input parameters a nd wave energy converter ( WEC ) array deployment scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that wave direction and WEC device type we r e most sensitive to the variation in the model parameters examined in this study . Generally, the changes in wave height we re the primary alteration caused by the presence of a WEC array. Specifically, W EC device type and subsequently their size directly re sult ed in wave height variations; however, it is important to utilize ongoing laboratory studies and future field tests to determine the most appropriate power matrix values for a particular WEC device and configuration in order to improve modeling results .

Roberts, Jesse D.; Chang, Grace; Magalen, Jason; Jones, Craig

2014-09-01T23:59:59.000Z

413

SECONDARY WAVES AND/OR THE 'REFLECTION' FROM AND 'TRANSMISSION' THROUGH A CORONAL HOLE OF AN EXTREME ULTRAVIOLET WAVE ASSOCIATED WITH THE 2011 FEBRUARY 15 X2.2 FLARE OBSERVED WITH SDO/AIA AND STEREO/EUVI  

SciTech Connect (OSTI)

For the first time, the kinematic evolution of a coronal wave over the entire solar surface is studied. Full Sun maps can be made by combining images from the Solar Terrestrial Relations Observatory satellites, Ahead and Behind, and the Solar Dynamics Observatory, thanks to the wide angular separation between them. We study the propagation of a coronal wave, also known as the 'Extreme Ultraviolet Imaging Telescope' wave, and its interaction with a coronal hole (CH) resulting in secondary waves and/or reflection and transmission. We explore the possibility of the wave obeying the law of reflection. In a detailed example, we find that a loop arcade at the CH boundary cascades and oscillates as a result of the extreme ultraviolet (EUV) wave passage and triggers a wave directed eastward that appears to have reflected. We find that the speed of this wave decelerates to an asymptotic value, which is less than half of the primary EUV wave speed. Thanks to the full Sun coverage we are able to determine that part of the primary wave is transmitted through the CH. This is the first observation of its kind. The kinematic measurements of the reflected and transmitted wave tracks are consistent with a fast-mode magnetohydrodynamic wave interpretation. Eventually, all wave tracks decelerate and disappear at a distance. A possible scenario of the whole process is that the wave is initially driven by the expanding coronal mass ejection and subsequently decouples from the driver and then propagates at the local fast-mode speed.

Olmedo, Oscar; Vourlidas, Angelos [Space Science Division, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Zhang Jie [School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Cheng Xin, E-mail: oscar.olmedo.ctr@nrl.navy.mil [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

2012-09-10T23:59:59.000Z

414

Bursting in a Subcritical Hopf Oscillator with a Nonlinear Feedback  

E-Print Network [OSTI]

Bursting is a periodic transition between a quiescent state and a state of repetitive spiking. The phenomenon is ubiquitous in a variety of neurophysical systems. We numerically study the dynamical properties of a normal form of subcritical Hopf oscillator (at the bifurcation point) subjected to a nonlinear feedback. This dynamical system shows an infinite-period or a saddle-node on a limit cycle (SNLC) bifurcation for certain strengths of the nonlinear feedback. When the feedback is time delayed, the bifurcation scenario changes and the limit cycle terminates through a homoclinic or a saddle separatrix loop (SSL) bifurcation. This system when close to the bifurcation point exhibits various types of bursting phenomenon when subjected to a slow periodic external stimulus of an appropriate strength. The time delay in the feedback enhances the spiking rate i.e. reduces the interspike interval in a burst and also increases the width or the duration of a burst.

Gautam C Sethia; Abhijit Sen

2006-03-24T23:59:59.000Z

415

Injection locked oscillator system for pulsed metal vapor lasers  

DOE Patents [OSTI]

An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

1988-01-01T23:59:59.000Z

416

Millimeter Wave Sensor For On-Line Inspection Of Thin Sheet Dielectrics  

DOE Patents [OSTI]

A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components. A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components.

Bakhtiari, Sasan (Westmont, IL); Gopalsami, Nachappa (Naperville, IL); Raptis, Apostolos C. (Downers Grove, IL)

1999-03-23T23:59:59.000Z

417

Wave-particle Interactions In Rotating Mirrors  

SciTech Connect (OSTI)

Wave-particle interactions in E×B rotating plasmas feature an unusual effect: particles are diffused by waves in both potential energy and kinetic energy. This wave-particle interaction generalizes the alpha channeling effect, in which radio frequency waves are used to remove alpha particles collisionlessly at low energy. In rotating plasmas, the alpha particles may be removed at low energy through the loss cone, and the energy lost may be transferred to the radial electric field. This eliminates the need for electrodes in the mirror throat, which have presented serious technical issues in past rotating plasma devices. A particularly simple way to achieve this effect is to use a high azimuthal mode number perturbation on the magnetic field. Rotation can also be sustained by waves in plasmas without a kinetic energy source. This type of wave has been considered for plasma centrifuges used for isotope separation. Energy may also be transferred from the electric field to particles or waves, which may be useful for ion heating and energy generation.

Abraham J. Fetterman and Nathaniel J. Fisch

2011-01-11T23:59:59.000Z

418

Optics in a nonlinear gravitational wave  

E-Print Network [OSTI]

Gravitational waves can act like gravitational lenses, affecting the observed positions, brightnesses, and redshifts of distant objects. Exact expressions for such effects are derived here, allowing for arbitrarily-moving sources and observers in the presence of plane-symmetric gravitational waves. The commonly-used predictions of linear perturbation theory are shown to be generically overshadowed---even for very weak gravitational waves---by nonlinear effects when considering observations of sufficiently distant sources; higher-order perturbative corrections involve secularly-growing terms which cannot necessarily be neglected. Even on more moderate scales where linear effects remain at least marginally dominant, nonlinear corrections are qualitatively different from their linear counterparts. There is a sense in which they can, for example, mimic the existence of a third type of gravitational wave polarization.

Harte, Abraham I

2015-01-01T23:59:59.000Z

419

Section 12: Waves and acoustics 1 Section 12: Waves and acoustics  

E-Print Network [OSTI]

Highly Porous Media Abstract 13:50 ­ 14:10: Hoffmann, N.P., Chabchoub, A. (TU Hamburg-Harburg): Experiments on Peregrine soliton type deep water gravity waves Abstract 14:10 ­ 14:30: Thomas Müllner (TU Wien): Acoustical performance of concreted wood fiber materials Abstract S12.4: Elastic Waves Wed, 16:00­18:00 Chair

Kohlenbach, Ulrich

420

The Quasi-Coherent Oscillations of SS Cygni  

E-Print Network [OSTI]

Properties of the quasi-coherent oscillations in the extreme ultraviolet (EUV) flux of the dwarf nova SS Cygni are described, with emphasis on (1) the scaling between the period of the oscillation and the EUV flux and (2) the mean power spectra and waveforms. In addition, a quasi-coherent oscillation at \

Christopher W. Mauche

1996-08-22T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Time-domain Dynamics and Stability Analysis of Optoelectronic Oscillators  

E-Print Network [OSTI]

Time-domain Dynamics and Stability Analysis of Optoelectronic Oscillators based on Whispering and Yanne K. Chembo Optoelectronic oscillators (OEOs) are microwave photonics systems in- tended to generate in "" #12;1 Introduction The optoelectronic oscillator (OEO) is nowadays considered as one of the most

Paris-Sud XI, Université de

422

A LOW-VOLTAGE TEMPERATURE-STABLE MICROMECHANICAL PIEZOELECTRIC OSCILLATOR  

E-Print Network [OSTI]

A LOW-VOLTAGE TEMPERATURE-STABLE MICROMECHANICAL PIEZOELECTRIC OSCILLATOR Reza Abdolvand, Hossein polarization voltages (5-20V) for operation, which complicates the design of the oscillator circuit in today reference oscillator that utilizes a temperature-stable thin- film piezoelectric-on-silicon resonator

Ayazi, Farrokh

423

Metabolic and Electrical Oscillations: Partners in Controlling Rhythmic Islet Activity  

E-Print Network [OSTI]

Bursting Oscillations Simultaneous fast Ca2+ and voltage measurements from a mouse islet in 11.1 mM glucose+ and voltage from an islet... ...have period similar to slow insulin oscillations measured from a mouse in vivoMetabolic and Electrical Oscillations: Partners in Controlling Rhythmic Islet Activity Richard

Bertram, Richard

424

DCS1800/WCDMA ADAPTIVE VOLTAGE-CONTROLLED OSCILLATOR  

E-Print Network [OSTI]

DCS1800/WCDMA ADAPTIVE VOLTAGE-CONTROLLED OSCILLATOR Aleksandar Tasiü, Wouter A. Serdijn and John R, an adaptive 2G/3G voltage-controlled oscillator (VCO) is described in this paper. For the DCS1800 operation with this reasoning, an adaptive 2G/3G voltage- controlled oscillator, meant for a dual-standard adaptive front

Serdijn, Wouter A.

425

PH-315 A. La Rosa VOLTAGE-CONTROLLED OSCILLATOR  

E-Print Network [OSTI]

PH-315 A. La Rosa VOLTAGE-CONTROLLED OSCILLATOR 1. PURPOSE: An integrator and a Schmitt Trigger voltage; hence its name "voltage-controlled oscillator." 2. VOLTAGE-CONTROLLED OSCILLATOR Figure 1 shows voltage. An unusual feature of the circuit is its operation using a single positive supply.1 #12;- + 50k V

426

Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator  

E-Print Network [OSTI]

Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator 1. The harmonic oscillator solution: displacement as a function of time We wish to solve the equation of motion for the simple harmonic oscillator shall employ for solving this di#erential equation is called the method of inspired guessing. In class

California at Santa Cruz, University of

427

Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator  

E-Print Network [OSTI]

Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator 1. The harmonic oscillator solution: displacement as a function of time We wish to solve the equation of motion for the simple harmonic oscillator employ for solving this differential equation is called the method of inspired guessing. In class, we

California at Santa Cruz, University of

428

Simscape Design Flow for Memristor Based Programmable Oscillators  

E-Print Network [OSTI]

oscillator is characterized within the Simscape framework. The oscillation frequency and power consumption of memristor-based oscillators. (2) A Gravitational Search Algorithm (GSA) based optimization algorithm in terms of power consumption and frequency. (4) The first ever Simscape based models for titanium oxide

Mohanty, Saraju P.

429

Analysis of oscillation characteristics and optimal conditions for high power operation of Gyrotron FU CW GIII  

SciTech Connect (OSTI)

The oscillation characteristics of Gyrotron FU CW GIII and its wave frequency and output power dependences on the magnetic field strength, the gun coil current, and the anode voltage were investigated experimentally. The experimental results were analyzed theoretically using a self-consistent code that included the electron properties in the cavity, corresponding to the actual operating conditions in the experiments. As a result, it was found that the variation in frequency with the magnetic field strength was related to an axial profile change in the electromagnetic wave in the cavity. In addition, the optimal condition that gives the maximum output power was found to be determined by the pitch factor rather than by the electron beam radius under the given operating conditions.

Tatematsu, Y., E-mail: tatema@fir.u-fukui.ac.jp; Yamaguchi, Y.; Kawase, T.; Ichioka, R.; Ogawa, I.; Saito, T.; Idehara, T. [Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507 (Japan)

2014-08-15T23:59:59.000Z

430

Classical and quantum dynamics in the (non-Hermitian) Swanson oscillator  

E-Print Network [OSTI]

The non-Hermitian quadratic oscillator studied by Swanson is one of the popular $PT$-symmetric model systems. Here a full classical description of its dynamics is derived using recently developed metriplectic flow equations, which combine the classical symplectic flow for Hermitian systems with a dissipative metric flow for the anti-Hermitian part. Closed form expressions for the metric and phase-space trajectories are presented which are found to be periodic in time. Since the Hamiltonian is only quadratic the classical dynamics exactly describes the quantum dynamics of Gaussian wave packets. It is shown that the classical metric and trajectories as well as the quantum wave functions can diverge in finite time even though the $PT$-symmetry is unbroken, i.e., the eigenvalues are purely real.

Eva-Maria Graefe; Hans Jürgen Korsch; Alexander Rush; Roman Schubert

2014-12-21T23:59:59.000Z

431

A comparison between matter wave and light wave interferometers for the detection of gravitational waves  

E-Print Network [OSTI]

We calculate and compare the response of light wave interferometers and matter wave interferometers to gravitational waves. We find that metric matter wave interferometers will not challenge kilometric light wave interferometers such as Virgo or LIGO, but could be a good candidate for the detection of very low frequency gravitational waves.

Pacôme Delva; Marie-Christine Angonin; Philippe Tourrenc

2006-09-20T23:59:59.000Z

432

Self-generation and management of spin-electromagnetic wave solitons and chaos  

SciTech Connect (OSTI)

Self-generation of microwave spin-electromagnetic wave envelope solitons and chaos has been observed and studied. For the investigation, we used a feedback active ring oscillator based on artificial multiferroic, which served as a nonlinear waveguide. We show that by increasing the wave amplification in the feedback ring circuit, a transition from monochromatic auto-generation to soliton train waveform and then to dynamical chaos occurs in accordance with the Ruelle-Takens scenario. Management of spin-electromagnetic-wave solitons and chaos parameters by both dielectric permittivity and magnetic permeability of the multiferroic waveguiding structure is demonstrated.

Ustinov, Alexey B.; Kondrashov, Alexandr V.; Nikitin, Andrey A.; Kalinikos, Boris A. [Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation)

2014-06-09T23:59:59.000Z

433

A Modified Fermi Model for Wave-Particle Interactions in Plasmas  

SciTech Connect (OSTI)

Wave-particle interactions in plasmas are investigated through a nonlinear map that describes elastic collisions between an ensemble of particles and two barriers. The amplitude of the barriers, proportional to the energy of the wave, can increase or decrease due to the sequence of stochastic collisions. After an initial exponential decrease, the nonlinear strong trapping regime is characterized by low-frequency oscillations of the amplitude of the barriers around a certain saturation value. This is a transitory phenomenon stemming from the dynamical approach towards equilibrium in the wave-particle conservative system.

De Marco, Rossana; Carbone, Vincenzo; Veltri, Pierluigi [Dipartimento di Fisica and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Universita della Calabria, Ponte P. Bucci Cubo 31C, 87036 Rende (Serbia and Montenegro) (Italy)

2006-03-31T23:59:59.000Z

434

Negative-mass Instability in Nonlinear Plasma Waves  

SciTech Connect (OSTI)

The negative-mass instability (NMI), previously found in ion traps, appears as a distinct regime of the sideband instability in nonlinear plasma waves with trapped particles. As the bounce frequency of these particles decreases with the bounce action, bunching can occur if the action distribution is inverted in trapping islands. In contrast to existing theories that also infer instabilities from the anharmonicity of bounce oscillations, spatial periodicity of the islands turns out to be unimportant, and the particle distribution can be unstable even if it is at at the resonance. An analytical model is proposed which describes both single traps and periodic nonlinear waves and concisely generalizes the conventional description of the sideband instability in plasma waves. The theoretical results are supported by particle-in-cell simulations carried out for a regime accentuating the NMI effect.

I.Y. Dodin, P.F. Schmit, J. Rocks and N.J. Fisch

2013-01-30T23:59:59.000Z

435

Slow oscillations of KATP conductance in mouse pancreatic islets provide support for electrical bursting driven by metabolic oscillations  

E-Print Network [OSTI]

of the ramp current-voltage curves, oscillated and was larger during the silent phase than during the activeSlow oscillations of KATP conductance in mouse pancreatic islets provide support for electrical bursting driven by metabolic oscillations Jianhua Ren,1 Arthur Sherman,2 Richard Bertram,3 Paulette B

Bertram, Richard

436

Identification for a Nonlinear Periodic Wave Equation  

SciTech Connect (OSTI)

This work is concerned with an approximation process for the identification of nonlinearities in the nonlinear periodic wave equation. It is based on the least-squares approach and on a splitting method. A numerical algorithm of gradient type and the numerical implementation are given.

Morosanu, C. [Department of Mathematics, University 'Al.I.Cuza', 6600 Iasi (Romania); Trenchea, C. [Institute of Mathematics of Romanian Academy, 6600 Iasi (Romania)

2001-07-01T23:59:59.000Z

437

Chimeras in globally coupled oscillatory systems: From ensembles of oscillators to spatially continuous media  

E-Print Network [OSTI]

We study an oscillatory medium with a nonlinear global coupling that gives rise to a harmonic mean-field oscillation with constant amplitude and frequency. Two types of cluster states are found, each undergoing a symmetry-breaking transition towards a related chimera state. We demonstrate that the diffusional coupling is non-essential for these complex dynamics. Furthermore, we investigate localized turbulence and discuss the question of a precise definition for chimera states.

Lennart Schmidt; Katharina Krischer

2015-03-13T23:59:59.000Z

438

Feedback control of an azimuthal oscillation in the E Multiplication-Sign B discharge of Hall thrusters  

SciTech Connect (OSTI)

Feedback control of a low-frequency azimuthal wave known as a 'rotating spoke' in the E Multiplication-Sign B discharge of a cylindrical Hall thruster was demonstrated. The rotating spoke is an m = 1 azimuthal variation in density, electron temperature, and potential that rotates at about 10% of the local E Multiplication-Sign B electron rotation speed. It causes increased electron transport across the magnetic field and is suspected to be an ionization wave. Feedback control of this wave required special consideration because, although it causes a rotating azimuthal variation in the current density to the anode, it does not show up as a signal in the total thruster discharge current. Therefore, an extra source of information was needed to track the oscillation, which was addressed by using a special anode that was split azimuthally into four segments. The current to each segment oscillates as the rotating spoke passes over it, and feedback is accomplished by resistors connected in series with each anode segment which causes the voltage on a segment to decrease in proportion to the current through that segment. The feedback resulted in the disappearance of a coherent azimuthal wave and a decrease in the time-averaged total discharge current by up to 13.2%.

Griswold, M. E.; Ellison, C. L.; Raitses, Y.; Fisch, N. J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2012-05-15T23:59:59.000Z

439

Chaotic oscillation and random-number generation based on nanoscale optical-energy transfer  

E-Print Network [OSTI]

By using nanoscale energy-transfer dynamics and density matrix formalism, we demonstrate theoretically and numerically that chaotic oscillation and random-number generation occur in a nanoscale system. The physical system consists of a pair of quantum dots (QDs), with one QD smaller than the other, between which energy transfers via optical near-field interactions. When the system is pumped by continuous-wave radiation and incorporates a timing delay between two energy transfers within the system, it emits optical pulses. We refer to such QD pairs as nano-optical pulsers (NOPs). Irradiating an NOP with external periodic optical pulses causes the oscillating frequency of the NOP to synchronize with the external stimulus. We find that chaotic oscillation occurs in the NOP population when they are connected by an external time delay. Moreover, by evaluating the time-domain signals by statistical-test suites, we confirm that the signals are sufficiently random to qualify the system as a random-number generator (RNG). This study reveals that even relatively simple nanodevices that interact locally with each other through optical energy transfer at scales far below the wavelength of irradiating light can exhibit complex oscillatory dynamics. These findings are significant for applications such as ultrasmall RNGs.

Makoto Naruse; Song-Ju Kim; Masashi Aono; Hirokazu Hori; Motoichi Ohtsu

2014-12-19T23:59:59.000Z

440

Nonlinear spherical Alfven waves  

E-Print Network [OSTI]

We present an one-dimensional numerical study of Alfven waves propagating along a radial magnetic field. Neglecting losses, any spherical Alfven wave, no matter how small its initial amplitude is, becomes nonlinear at sufficiently large radii. From previous simulations of Alfven waves in plane parallel atmospheres we did expect the waves to steepen and produce current sheets in the nonlinear regime, which was confirmed by our new calculations. On the other hand we did find that even the least nonlinear waves were damped out almost completely before 10 solar radii. A damping of that kind is required by models of Alfven wave-driven winds from old low-mass stars as these winds are mainly accelerated within a few stellar radii.

Ulf Torkelsson; G. Christopher Boynton

1997-09-23T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Wave propagation in axion electrodynamics  

E-Print Network [OSTI]

In this paper, the axion contribution to the electromagnetic wave propagation is studied. First we show how the axion electrodynamics model can be embedded into a premetric formalism of Maxwell electrodynamics. In this formalism, the axion field is not an arbitrary added Chern-Simon term of the Lagrangian, but emerges in a natural way as an irreducible part of a general constitutive tensor.We show that in order to represent the axion contribution to the wave propagation it is necessary to go beyond the geometric approximation, which is usually used in the premetric formalism. We derive a covariant dispersion relation for the axion modified electrodynamics. The wave propagation in this model is studied for an axion field with timelike, spacelike and null derivative covectors. The birefringence effect emerges in all these classes as a signal of Lorentz violation. This effect is however completely different from the ordinary birefringence appearing in classical optics and in premetric electrodynamics. The axion field does not simple double the ordinary light cone structure. In fact, it modifies the global topological structure of light cones surfaces. In CFJ-electrodynamics, such a modification results in violation of causality. In addition, the optical metrics in axion electrodynamics are not pseudo-Riemannian. In fact, for all types of the axion field, they are even non-Finslerian.

Yakov Itin

2007-06-20T23:59:59.000Z

442

Hysteresis of ionization waves  

SciTech Connect (OSTI)

A quasi-logistic, nonlinear model for ionization wave modes is introduced. Modes are due to finite size of the discharge and current feedback. The model consists of competing coupled modes and it incorporates spatial wave amplitude saturation. The hysteresis of wave mode transitions under current variation is reproduced. Sidebands are predicted by the model and found in experimental data. The ad hoc model is equivalent to a general--so-called universal--approach from bifurcation theory.

Dinklage, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); Bruhn, B.; Testrich, H. [Institut fuer Physik, E.-M.-Arndt Universitaet Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald (Germany); Wilke, C. [Leibniz-Institut fuer Plasmaforschung und Technologie, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

2008-06-15T23:59:59.000Z

443

Neutrino Oscillation Experiments at Nuclear Reactors  

E-Print Network [OSTI]

In this paper I give an overview of the status of neutrino oscillation experiments performed using nuclear reactors as sources of neutrinos. I review the present generation of experiments (Chooz and Palo Verde) with baselines of about 1 km as well as the next generation that will search for oscillations with a baseline of about 100 km. While the present detectors provide essential input towards the understanding of the atmospheric neutrino anomaly, in the future, the KamLAND reactor experiment represents our best opportunity to study very small mass neutrino mixing in laboratory conditions. In addition KamLAND with its very large fiducial mass and low energy threshold, will also be sensitive to a broad range of different physics.

Giorgio Gratta

1999-05-06T23:59:59.000Z

444

On the Critical Coupling for Kuramoto Oscillators  

E-Print Network [OSTI]

The celebrated Kuramoto model captures various synchronization phenomena in biological and man-made dynamical systems of coupled oscillators. It is well-known that there exists a critical coupling strength among the oscillators at which a phase transition from incoherency to synchronization occurs. This paper features three contributions. First, we characterize and distinguish the different notions of synchronization used throughout the literature and formally introduce the concept of phase cohesiveness as an analysis tool and performance index for synchronization. Second, we review the vast literature providing necessary, sufficient, implicit, and explicit estimates of the critical coupling strength in the finite and infinite-dimensional case. Finally, we present the first explicit necessary and sufficient condition on the critical coupling strength to achieve synchronization in the finite-dimensional Kuramoto model for an arbitrary distribution of the natural frequencies. The multiplicative gap in the synch...

Dorfler, Florian

2010-01-01T23:59:59.000Z

445

PROSPECT - A precision oscillation and spectrum experiment  

E-Print Network [OSTI]

Segmented antineutrino detectors placed near a compact research reactor provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. Close proximity to a reactor combined with minimal overburden yield a high background environment that must be managed through shielding and detector technology. PROSPECT is a new experimental effort to detect reactor antineutrinos from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, managed by UT Battelle for the U.S. Department of Energy. The detector will use novel lithium-loaded liquid scintillator capable of neutron/gamma pulse shape discrimination and neutron capture tagging. These enhancements improve the ability to identify neutrino inverse-beta decays and reject background events in analysis. Results from these efforts will be covered along with their implications for an oscillation search and a precision spectrum measurement.

T. J. Langford

2014-12-22T23:59:59.000Z

446

PROSPECT - A precision oscillation and spectrum experiment  

E-Print Network [OSTI]

Segmented antineutrino detectors placed near a compact research reactor provide an excellent opportunity to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. Close proximity to a reactor combined with minimal overburden yield a high background environment that must be managed through shielding and detector technology. PROSPECT is a new experimental effort to detect reactor antineutrinos from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, managed by UT Battelle for the U.S. Department of Energy. The detector will use novel lithium-loaded liquid scintillator capable of neutron/gamma pulse shape discrimination and neutron capture tagging. These enhancements improve the ability to identify neutrino inverse-beta decays and reject background events in analysis. Results from these efforts will be covered along with their implications for an oscillation search and a precision spectrum measurement.

,

2015-01-01T23:59:59.000Z

447

Structure-borne sound Flexural wave (bending wave)  

E-Print Network [OSTI]

1 Structure-borne sound · Flexural wave (bending wave) »One dimensional (beam) +(/x)dx +(/x)dx = (/x) (/x)dx=(2/x2)dx Mz +(Mz/x)dx Mz vy Fy Fy +(Fy/x)dx Structure-borne sound · Bending wave ­ flexural wave #12;2 Structure-borne sound · Two obliquely propagating waves + - + + - + - Structure

Berlin,Technische Universität

448

Wave Propagation Theory 2.1 The Wave Equation  

E-Print Network [OSTI]

2 Wave Propagation Theory 2.1 The Wave Equation The wave equation in an ideal fluid can be derived #12;66 2. Wave Propagation Theory quantities of the quiescent (time independent) medium are identified perturbations is much smaller than the speed of sound. 2.1.1 The Nonlinear Wave Equation Retaining higher

449

Wave momentum flux parameter: a descriptor for nearshore waves  

E-Print Network [OSTI]

Wave momentum flux parameter: a descriptor for nearshore waves Steven A. Hughes* US Army Engineer Available online 7 October 2004 Abstract A new parameter representing the maximum depth-integrated wave momentum flux occurring over a wave length is proposed for characterizing the wave contribution

US Army Corps of Engineers

450

Shallow Water Waves and Solitary Waves Willy Hereman  

E-Print Network [OSTI]

Shallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer of the Subject II. Introduction­Historical Perspective III. Completely Integrable Shallow Water Wave Equations IV. Shallow Water Wave Equations of Geophysical Fluid Dynamics V. Computation of Solitary Wave Solutions VI

Hereman, Willy A.M.

451

Mapping the nano-Hertz gravitational wave sky  

E-Print Network [OSTI]

We describe a new method for extracting gravitational wave signals from pulsar timing data. We show that any gravitational wave signal can be decomposed into an orthogonal set of sky maps, with the number of maps equal to the number of pulsars in the timing array. These maps may be used as a basis to construct gravitational wave templates for any type of source, including collections of point sources. A variant of the standard Hellings-Downs correlation analysis is recovered for statistically isotropic signals. The template based approach allows us to probe potential anisotropies in the signal and produce maps of the gravitational wave sky.

Neil J. Cornish; Rutger van Haasteren

2014-06-19T23:59:59.000Z

452

Mass transfer at vertically oscillating surfaces  

SciTech Connect (OSTI)

An analysis of mass transfer at vertically oscillating surfaces is presented. It takes into account the interaction between forced and natural convection and can be used under conditions where the fluid velocity outside the boundary layer changes direction. Because of the good agreement with experimental data, the model can explain the multi-fold increase in mass transfer coefficient obtained under oscillatory conditions. 8 refs., 3 figs.

Gomaa, H.G. [Ontario Hydro Nuclear, Tiverton, Ontario (Canada); Landau, J. [Univ. of New Brunswick, Fredericton, NB (Canada); Tawell, A.M.A. [Technical Univ. of Nova Scotia, Halifax, NS (Canada)

1996-12-31T23:59:59.000Z

453

On the Critical Coupling for Kuramoto Oscillators  

E-Print Network [OSTI]

The Kuramoto model captures various synchronization phenomena in biological and man-made systems of coupled oscillators. It is well-known that there exists a critical coupling strength among the oscillators at which a phase transition from incoherency to synchronization occurs. This paper features four contributions. First, we characterize and distinguish the different notions of synchronization used throughout the literature and formally introduce the concept of phase cohesiveness as an analysis tool and performance index for synchronization. Second, we review the vast literature providing necessary, sufficient, implicit, and explicit estimates of the critical coupling strength for finite and infinite-dimensional, and for first and second-order Kuramoto models. Third, we present the first explicit necessary and sufficient condition on the critical coupling to achieve synchronization in the finite-dimensional Kuramoto model for an arbitrary distribution of the natural frequencies. The multiplicative gap in the synchronization condition yields a practical stability result determining the admissible initial and the guaranteed ultimate phase cohesiveness as well as the guaranteed asymptotic magnitude of the order parameter. Fourth and finally, we extend our analysis to multi-rate Kuramoto models consisting of second-order Kuramoto oscillators with inertia and viscous damping together with first-order Kuramoto oscillators with multiple time constants. We prove that the multi-rate Kuramoto model is locally topologically conjugate to a first-order Kuramoto model with scaled natural frequencies, and we present necessary and sufficient conditions for almost global phase synchronization and local frequency synchronization. Interestingly, these conditions do not depend on the inertiae which contradicts prior observations on the role of inertiae in synchronization of second-order Kuramoto models.

Florian Dorfler; Francesco Bullo

2011-05-05T23:59:59.000Z

454

Quantum decoherence of the damped harmonic oscillator  

E-Print Network [OSTI]

In the framework of the Lindblad theory for open quantum systems, we determine the degree of quantum decoherence of a harmonic oscillator interacting with a thermal bath. It is found that the system manifests a quantum decoherence which is more and more significant in time. We also calculate the decoherence time and show that it has the same scale as the time after which thermal fluctuations become comparable with quantum fluctuations.

A. Isar

2006-06-27T23:59:59.000Z

455

${\\cal D}$-deformed harmonic oscillators  

E-Print Network [OSTI]

We analyze systematically several deformations arising from two-dimensional harmonic oscillators which can be described in terms of $\\cal{D}$-pseudo bosons. They all give rise to exactly solvable models, described by non self-adjoint hamiltonians whose eigenvalues and eigenvectors can be found adopting the quite general framework of the so-called $\\cal{D}$-pseudo bosons. In particular, we show that several models previously introduced in the literature perfectly fit into this scheme.

F. Bagarello; F. Gargano; D. Volpe

2014-12-30T23:59:59.000Z

456

Directed Relativistic Blast Wave  

E-Print Network [OSTI]

A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion. Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in. We show however, that a directed relativistic explosion, with the explosion momentum close to the explosion energy, produces a blast wave with a universal intermediate asymptotic -- a selfsimilar directed ultra-relativistic blast wave. This universality might be of interest for the astrophysics of gamma-ray burst afterglows.

Andrei Gruzinov

2007-04-23T23:59:59.000Z

457

High frequency inductive lamp and power oscillator  

DOE Patents [OSTI]

A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and I or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to adjust the driving frequency of the oscillator.

MacLennan, Donald A. (Gaithersburg, MD); Dymond, Jr., Lauren E. (North Potomac, MD); Gitsevich, Aleksandr (Montgomery Village, MD); Grimm, William G. (Silver Spring, MD); Kipling, Kent (Gaithersburg, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Ola, Samuel A. (Silver Spring, MD); Simpson, James E. (Gaithersburg, MD); Trimble, William C. (Columbia, MD); Tsai, Peter (Olney, MD); Turner, Brian P. (Damascus, MD)

2001-01-01T23:59:59.000Z

458

Oscillating plasma bubbles. II. Pulsed experiments  

SciTech Connect (OSTI)

Time-dependent phenomena have been investigated in plasma bubbles which are created by inserting spherical grids into an ambient plasma and letting electrons and ions form a plasma of different parameters than the ambient one. There are no plasma sources inside the bubble. The grid bias controls the particle flux. There are sheaths on both sides of the grid, each of which passes particle flows in both directions. The inner sheath or plasma potential develops self consistently to establish charge neutrality and divergence free charge and mass flows. When the electron supply is restricted, the inner sheath exhibits oscillations near the ion plasma frequency. When all electrons are excluded, a virtual anode forms on the inside sheath, reflects all ions such that the bubble is empty. By pulsing the ambient plasma, the lifetime of the bubble plasma has been measured. In an afterglow, plasma electrons are trapped inside the bubble and the bubble decays as slow as the ambient plasma. Pulsing the grid voltage yields the time scale for filling and emptying the bubble. Probes have been shown to modify the plasma potential. Using pulsed probes, transient ringing on the time scale of ion transit times through the bubble has been observed. The start of sheath oscillations has been investigated. The instability mechanism has been qualitatively explained. The dependence of the oscillation frequency on electrons in the sheath has been clarified.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

2012-08-15T23:59:59.000Z

459

High frequency inductive lamp and power oscillator  

DOE Patents [OSTI]

A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

MacLennan, Donald A. (Gaithersburg, MD); Turner, Brian P. (Damascus, MD); Dolan, James T. (Frederick, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Leng, Yongzhang (Damascus, MD)

2000-01-01T23:59:59.000Z

460

Three Dimensional MHD Wave Propagation and Conversion to Alfven Waves near the Solar Surface. I. Direct Numerical Solution  

E-Print Network [OSTI]

The efficacy of fast/slow MHD mode conversion in the surface layers of sunspots has been demonstrated over recent years using a number of modelling techniques, including ray theory, perturbation theory, differential eigensystem analysis, and direct numerical simulation. These show that significant energy may be transferred between the fast and slow modes in the neighbourhood of the equipartition layer where the Alfven and sound speeds coincide. However, most of the models so far have been two dimensional. In three dimensions the Alfven wave may couple to the magneto-acoustic waves with important implications for energy loss from helioseismic modes and for oscillations in the atmosphere above the spot. In this paper, we carry out a numerical ``scattering experiment'', placing an acoustic driver 4 Mm below the solar surface and monitoring the acoustic and Alfvenic wave energy flux high in an isothermal atmosphere placed above it. These calculations indeed show that energy conversion to upward travelling Alfven waves can be substantial, in many cases exceeding loss to slow (acoustic) waves. Typically, at penumbral magnetic field strengths, the strongest Alfven fluxes are produced when the field is inclined 30-40 degrees from the vertical, with the vertical plane of wave propagation offset from the vertical plane containing field lines by some 60-80 degrees.

P. S. Cally; M. Goossens

2007-11-04T23:59:59.000Z

Note: This page contains sample records for the topic "type oscillating wave" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Discontinuously propagating waves in the bathoferroin-catalyzed BelousovZhabotinsky reaction incorporated into a microemulsion  

E-Print Network [OSTI]

Discontinuously propagating waves in the bathoferroin-catalyzed Belousov­Zhabotinsky reaction new types of discontinuously propagating waves are reported in the bathoferroin-catalyzed Belousov at higher temperatures 40 °C . All these waves propagate discontinuously in a saltatory fashion. Other

Epstein, Irving R.

462

EVIDENCE FOR THE WAVE NATURE OF AN EXTREME ULTRAVIOLET WAVE OBSERVED BY THE ATMOSPHERIC IMAGING ASSEMBLY ON BOARD THE SOLAR DYNAMICS OBSERVATORY  

SciTech Connect (OSTI)

Extreme-ultraviolet (EUV) waves have been found for about 15 years. However, significant controversy remains over their physical natures and origins. In this paper, we report an EUV wave that was accompanied by an X1.9 flare and a partial halo coronal mass ejection (CME). Using high temporal and spatial resolution observations taken by the Solar Dynamics Observatory and the Solar-TErrestrial RElations Observatory, we are able to investigate the detailed kinematics of the EUV wave. We find several arguments that support the fast-mode wave scenario. (1) The speed of the EUV wave (570 km s{sup -1}) is higher than the sound speed of the quiet-Sun corona. (2) Significant deceleration of the EUV wave (-130 m s{sup -2}) is found during its propagation. (3) The EUV wave resulted in the oscillations of a loop and a filament along its propagation path, and a reflected wave from the polar coronal hole is also detected. (4) Refraction or reflection effect is observed when the EUV wave was passing through two coronal bright points. (5) The dimming region behind the wavefront stopped to expand when the wavefront started to become diffuse. (6) The profiles of the wavefront exhibited a dispersive nature, and the magnetosonic Mach number of the EUV wave derived from the highest intensity jump is about 1.4. In addition, triangulation indicates that the EUV wave propagated within a height range of about 60-100 Mm above the photosphere. We propose that the EUV wave observed should be a nonlinear fast-mode magnetosonic wave that propagated freely in the corona after it was driven by the CME expanding flanks during the initial period.

Shen Yuandeng; Liu Yu, E-mail: ydshen@ynao.ac.cn [Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

2012-07-20T23:59:59.000Z

463

Wave runup on cylinders subject to deep water random waves  

E-Print Network [OSTI]

was measured close to the test cylinders are analyzed. These data on wave runup in deepwater random waves were generated at similar water depths with significant wave heights and spectral peak periods. Statistical parameters, zero crossing analysis...

Indrebo, Ann Kristin

2012-06-07T23:59:59.000Z

464

THE ASTEROSEISMIC POTENTIAL OF KEPLER: FIRST RESULTS FOR SOLAR-TYPE STARS  

SciTech Connect (OSTI)

We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5 days of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: about 20 modes of oscillation may be clearly distinguished in each star. We discuss the appearance of the oscillation spectra, use the frequencies and frequency separations to provide first results on the radii, masses, and ages of the stars, and comment in the light of these results on prospects for inference on other solar-type stars that Kepler will observe.

Chaplin, W. J.; Elsworth, Y.; Karoff, C. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Appourchaux, T. [Institut d'Astrophysique Spatiale, Universite Paris XI-CNRS (UMR8617), Batiment 121, 91405 Orsay Cedex (France); GarcIa, R. A. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot-IRFU/SAp, 91191 Gif-sur-Yvette Cedex (France); Houdek, G. [Institute of Astronomy, University of Vienna, A-1180 Vienna (Austria); Metcalfe, T. S. [High Altitude Observatory and Scientific Computing Division, National Center for Atmospheric Research, Boulder, CO 80307 (United States); Molenda-Zakowicz, J. [Astronomical Institute, University of Wroclaw, ul. Kopernika, 11, 51-622 Wroclaw (Poland); Monteiro, M. J. P. F. G.; Bazot, M. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 (Portugal); Thompson, M. J. [School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Brown, T. M. [Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States); Christensen-Dalsgaard, J.; Kjeldsen, H. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Gilliland, R. L. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Borucki, W. J.; Koch, D. [NASA Ames Research Center, MS 244-30, Moffett Field, CA 94035 (United States); Jenkins, J. M. [SETI Institute/NASA Ames Research Center, MS 244-30, Moffett Field, CA 94035 (United States); Ballot, J. [Laboratoire d'Astrophysique de Toulouse-Tarbes, Universite de Toulouse, CNRS, 14 av E. Belin, 31400 Toulouse (France); Basu, S. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)] (and others)

2010-04-20T23:59:59.000Z

465

The asteroseismic potential of Kepler: first results for solar-type stars  

E-Print Network [OSTI]

We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5d of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: About 20 modes of oscillation may be clearly distinguished in each star. We discuss the appearance of the oscillation spectra, use the frequencies and frequency separations to provide first results on the radii, masses and ages of the stars, and comment in the light of these results on prospects for inference on other solar-type stars that Kepler will observe.

Chaplin, W J; Elsworth, Y; Garcia, R A; Houdek, G; Karoff, C; Metcalfe, T S; Molenda-Zakowicz, J; Monteiro, M J P F G; Thompson, M J; Brown, T M; Christensen-Dalsgaard, J; Gilliland, R L; Kjeldsen, H; Borucki, W J; Koch, D; Jenkins, J M; Ballot, J; Basu, S; Bazot, M; Bedding, T R; Benomar, O; Bonanno, A; Brandao, I M; Bruntt, H; Campante, T L; Creevey, O L; Di Mauro, M P; Dogan, G; Dreizler, S; Eggenberger, P; Esch, L; Fletcher, S T; Frandsen, S; Gai, N; Gaulme, P; Handberg, R; Hekker, S; Howe, R; Huber, D; Korzennik, S G; Lebrun, J C; Leccia, S; Martic, M; Mathur, S; Mosser, B; New, R; Quirion, P -O; Regulo, C; Roxburgh, I W; Salabert, D; Schou, J; Sousa, S G; Stello, D; Verner, G A; Arentoft, T; Barban, C; Belkacem, K; Benatti, S; Biazzo, K; Boumier, P; Bradley, P A; Broomhall, A -M; Buzasi, D L; Claudi, R U; Cunha, M S; D'Antona, F; Deheuvels, S; Derekas, A; Hernandez, A Garcia; Giampapa, M S; Goupil, M J; Gruberbauer, M; Guzik, J A; Hale, S J; Ireland, M J; Kiss, L L; Kitiashvili, I N; Kolenberg, K; Korhonen, H; Kosovichev, A G; Kupka, F; Lebreton, Y; Leroy, B; Ludwig, H -G; Mathis, S; Michel, E; Miglio, A; Montalban, J; Moya, A; Noels, A; Noyes, R W; Palle, P L; Piau, L; Preston, H L; Cortes, T Roca; Roth, M; Sato, K H; Schmitt, J; Serenelli, A M; Aguirre, V Silva; Stevens, I R; Suarez, J C; Suran, M D; Trampedach, R; Turck-Chieze, S; Uytterhoeven, K; Ventura, R

2010-01-01T23:59:59.000Z

466

Robust energy transfer mechanism and critically balanced turbulence via non-resonant triads in nonlinear wave systems  

E-Print Network [OSTI]

A robust energy transfer mechanism is found in nonlinear wave systems, which favours transfers towards modes interacting via non-resonant triads, applicable in meteorology, nonlinear optics and plasma wave turbulence. Transfer efficiency is maximal when the frequency mismatch of the non-resonant triad balances the system's nonlinear frequency: at intermediate levels of oscillation amplitudes an instability is triggered that explores unstable manifolds of periodic orbits, so turbulent cascades are most efficient at intermediate nonlinearity. Numerical simulations confirm analytical predictions.

Miguel D. Bustamante; Brenda Quinn

2013-09-02T23:59:59.000Z

467

Wave-Corpuscle Mechanics for Electric Charges  

E-Print Network [OSTI]

superposition in nonlinear wave dynamics. Rev. Math. Phys.6. Babin, A. , Figotin, A. : Wave-corpuscle mechanics forV. , Fortunato, D. : Solitary waves in the nonlinear wave

Babin, Anatoli; Figotin, Alexander

2010-01-01T23:59:59.000Z

468

Self-consistent full wave simulations of lower hybrid waves  

E-Print Network [OSTI]

Self-consistent full wave simulations of lower hybrid waves John C. Wright P. T. Bonoli - MIT E .J for Simulation of Wave-Plasma Interactions L.A. Berry, D.B. Batchelor, E.F. Jaeger, E. D`Azevedo D. Green C. Milanesio #12;3 Outline · Introduction to Lower Hybrid waves · Modeling LH waves ­ Ray tracing ­ Full Wave

Wright, John C.

469

Harmonic generation of gravitational wave induced Alfven waves  

E-Print Network [OSTI]

Here we consider the nonlinear evolution of Alfven waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfven waves. Due to the weak dispersion of the Alfven waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.

Mats Forsberg; Gert Brodin

2007-11-26T23:59:59.000Z

470

Developing de Broglie Wave  

E-Print Network [OSTI]

The electromagnetic component waves, comprising together with their generating oscillatory massless charge a material particle, will be Doppler shifted when the charge hence particle is in motion, with a velocity $v$, as a mere mechanical consequence of the source motion. We illustrate here that two such component waves generated in opposite directions and propagating at speed $c$ between walls in a one-dimensional box, superpose into a traveling beat wave of wavelength ${\\mit\\Lambda}_d$$=(\\frac{v}{c}){\\mit\\Lambda}$ and phase velocity $c^2/v+v$ which resembles directly L. de Broglie's hypothetic phase wave. This phase wave in terms of transporting the particle mass at the speed $v$ and angular frequency ${\\mit\\Omega}_d=2\\pi v /{\\mit\\Lambda}_d$, with ${\\mit\\Lambda}_d$ and ${\\mit\\Omega}_d$ obeying the de Broglie relations, represents a de Broglie wave. The standing-wave function of the de Broglie (phase) wave and its variables for particle dynamics in small geometries are equivalent to the eigen-state solutions to Schr\\"odinger equation of an identical system.

J X Zheng-Johansson; P-I Johansson

2006-08-27T23:59:59.000Z

471

Method and apparatus for suppressing waves in a borehole  

DOE Patents [OSTI]

Methods and apparatus for suppression of wave energy within a fluid-filled borehole using a low pressure acoustic barrier. In one embodiment, a flexible diaphragm type device is configured as an open bottomed tubular structure for disposition in a borehole to be filled with a gas to create a barrier to wave energy, including tube waves. In another embodiment, an expandable umbrella type device is used to define a chamber in which a gas is disposed. In yet another embodiment, a reverse acting bladder type device is suspended in the borehole. Due to its reverse acting properties, the bladder expands when internal pressure is reduced, and the reverse acting bladder device extends across the borehole to provide a low pressure wave energy barrier.

West, Phillip B.

2005-10-04T23:59:59.000Z

472

Center for Wave Phenomena Wave Phenomena  

E-Print Network [OSTI]

into a life of scientific discovery." Kurang Mehta, Ph.D. Class of 2007 Shell Exploration and Production Phil research and education program in seismic exploration, monitoring and wave propagation. The main focus and efficiency of seismic processing algorithms, especially for application to regions of structural complexity

473

Rainbow trapping of guided waves  

E-Print Network [OSTI]

Rainbow trapping of guided waves Javier Polanco and Rosa M.the propagation of a wave packet that is a superpositionof three s-polarized guided waves with different frequencies

Polanco, Javier; Fitzgerald, Rosa M; Leskova, Tamara A; Maradudin, Alexei A

2011-01-01T23:59:59.000Z

474

Arnold Schwarzenegger CALIFORNIA OCEAN WAVE  

E-Print Network [OSTI]

Arnold Schwarzenegger Governor CALIFORNIA OCEAN WAVE ENERGY ASSESSMENT Prepared For: California this report as follows: Previsic, Mirko. 2006. California Ocean Wave Energy Assessment. California Energy Systems Integration · Transportation California Ocean Wave Energy Assessment is the final report

475

Cloning and trapping of magnetostatic spin-wave pulses by parametric pumping Kevin R. Smith,1 Vitaliy I. Vasyuchka,1,2 Mingzhong Wu,1 Gennadiy A. Melkov,2 and Carl E. Patton1  

E-Print Network [OSTI]

Cloning and trapping of magnetostatic spin-wave pulses by parametric pumping Kevin R. Smith,1 media,3 phase noise re- duction in crystal oscillators,4 theoretical production of neutrino in nonlinear media. The specific work was done for 5 GHz magnetostatic spin-wave pulses in a single

Patton, Carl

476

Spicules Intensity Oscillations in SOT/HINODE Observations  

E-Print Network [OSTI]

Aims. We study the coherency of solar spicules intensity oscillations with increasing height above the solar limb in quiet Sun, active Sun and active region using observations from HINODE/SOT. Existence of coherency up to transition region strengthens the theory of the coronal heating and solar wind through energy transport and photospheric oscillations. Methods. Using time sequences from the HINODE/SOT in Ca II H line, we investigate oscillations found in intensity profiles at different heights above the solar limb. We use the Fourier and wavelet analysis to measure dominant frequency peaks of intensity at the heights, and phase difference between oscillations at two certain heights, to find evidence for the coherency of the oscillations. Finally, we can calculate the energy and the mass transported by spicules providing energy equilibrium, according to density values of spicules at different heights. To extend this work, we can also consider coherent oscillations at different latitudes and suggest to study ...

Tavabi, E; Maralani, A R Ahangarzadeh; Zeighami, S

2015-01-01T23:59:59.000Z

477

Diagonalization of pp-waves  

E-Print Network [OSTI]

A coordinate transformation is found which diagonalizes the axisymmetric pp-waves. Its effect upon concrete solutions, including impulsive and shock waves, is discussed.

B. V. Ivanov

1997-05-21T23:59:59.000Z

478

Harmonic oscillator chains as Wigner Quantum Systems: periodic and fixed wall boundary conditions in gl(1|n) solutions  

E-Print Network [OSTI]

We describe a quantum system consisting of a one-dimensional linear chain of n identical harmonic oscillators coupled by a nearest neighbor interaction. Two boundary conditions are taken into account: periodic boundary conditions (where the nth oscillator is coupled back to the first oscillator) and fixed wall boundary conditions (where the first oscillator and the $n$th oscillator are coupled to a fixed wall). The two systems are characterized by their Hamiltonian. For their quantization, we treat these systems as Wigner Quantum Systems (WQS), allowing more solutions than just the canonical quantization solution. In this WQS approach, one is led to certain algebraic relations for operators (which are linear combinations of position and momentum operators) that should satisfy triple relations involving commutators and anti-commutators. These triple relations have a solution in terms of the Lie superalgebra gl(1|n). We study a particular class of gl(1|n) representations V(p), the so-called ladder representations. For these representations, we determine the spectrum of the Hamiltonian and of the position operators (for both types of boundary conditions). Furthermore, we compute the eigenvectors of the position operators in terms of stationary states. This leads to explicit expressions for position probabilities of the n oscillators in the chain. An analysis of the plots of such position probability distributions gives rise to some interesting observations. In particular, the physical behavior of the system as a WQS is very much in agreement with what one would expect from the classical case, except that all physical quantities (energy, position and momentum of each oscillator) have a finite spectrum.

S. Lievens; N. I. Stoilova; J. Van der Jeugt

2007-09-03T23:59:59.000Z

479

Harmonic oscillator chains as Wigner quantum systems: Periodic and fixed wall boundary conditions in gl(1|n) solutions  

SciTech Connect (OSTI)

We describe a quantum system consisting of a one-dimensional linear chain of n identical harmonic oscillators coupled by a nearest neighbor interaction. Two boundary conditions are taken into account: periodic boundary conditions (where the nth oscillator is coupled back to the first oscillator) and fixed wall boundary conditions (where the first oscillator and the nth oscillator are coupled to a fixed wall). The two systems are characterized by their Hamiltonian. For their quantization, we treat these systems as Wigner quantum systems (WQSs), allowing more solutions than just the canonical quantization solution. In this WQS approach, one is led to certain algebraic relations for operators (which are linear combinations of position and momentum operators) that should satisfy triple relations involving commutators and anti-commutators. These triple relations have a solution in terms of the Lie superalgebra gl(1|n). We study a particular class of gl(1|n) representations V(p), the so-called ladder representations. For these representations, we determine the spectrum of the Hamiltonian and of the position operators (for both types of boundary conditions). Furthermore, we compute the eigenvectors of the position operators in terms of stationary states. This leads to explicit expressions for position probabilities of the n oscillators in the chain. An analysis of the plots of such position probability distributions gives rise to some interesting observations. In particular, the physical behavior of the system as a WQS is very much in agreement with what one would expect from the classical case, except that all physical quantities (energy, position, and momentum of each oscillator) have a finite spectrum.

Lievens, S.; Stoilova, N. I.; Jeugt, J. van der [Department of Applied Mathematics and Computer Science, Ghent University, Krijgslaan 281-S9, B-9000 Gent (Belgium)

2008-07-15T23:59:59.000Z

480

Analysis of Bs flavor oscillations at CDF  

SciTech Connect (OSTI)

The search for and study of flavor oscillations in the neutral B{sub s}B{sub s} meson system is an experimentally challenging task. It constitutes a flagship analysis of the Tevatron physics program. In this dissertation, they develop an analysis of the time-dependent B{sub s} flavor oscillations using data collected with the CDF detector. The data samples are formed of both fully and partially reconstructed B meson decays: B{sub s} {yields} D{sub s}{pi}({pi}{pi}) and B{sub s} {yields} D{sub s}lv. A likelihood fitting framework is implemented and appropriate models and techniques developed for describing the mass, proper decay time, and flavor tagging characteristics of the data samples. The analysis is extended to samples of B{sup +} and B{sup 0} mesons, which are further used for algorithm calibration and method validation. The B mesons lifetimes are extracted. The measurement of the B{sup 0} oscillation frequency yields {Delta}m{sub d} = 0.522 {+-} 0.017 ps{sup -1}. The search for B{sub s} oscillations is performed using an amplitude method based on a frequency scanning procedure. Applying a combination of lepton and jet charge flavor tagging algorithms, with a total tagging power {epsilon}'D{sup 2} of 1.6%, to a data sample of 355 pb{sup -1}, a sensitivity of 13.0 ps{sup -1} is achieved. They develop a preliminary same side kaon tagging algorithm, which is found to provide a superior tagging power of about 4.0% for the B{sub s} meson species. A study of the dilution systematic uncertainties is not reported. From its application as is to the B{sub s} samples the sensitivity is significantly increased to about 18 ps{sup -1} and a hint of a signal is seen at about 175. ps{sup -1}. They demonstrate that the extension of the analysis to the increasing data samples with the inclusion of the same side tagging algorithm is capable of providing an observation of B{sub s} mixing beyond the standard model expectation. They show also that the improved knowledge of {Delta}m{sub s} has a considerable impact on constraining the CKM matrix elements.

Leonardo, Nuno T

2006-09-01T23:59:59.000Z

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481

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