WorldWideScience

Sample records for nu-e oscillation appearance

  1. Studies of Nu-mu to Nu-e Oscillation Appearance in the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira e Sousa, Alexandre Bruno [Tufts Univ., Medford, MA (United States)

    2006-02-01

    The MINOS experiment uses a long baseline neutrino beam, measured 1 km downstream from its origin in the Near Detector at Fermilab, and 734 km later in the large underground Far Detector in the Soudan mine. By comparing these two measurements, MINOS can probe the atmospheric domain of the neutrino oscillation phenomenology with unprecedented precision. Besides the ability to perform a world leading determination of the Δm$2\\atop{23}$ and θ23 parameters, via vμ flux disappearance, MINOS has the potential to make a leading measurement of vμ → ve oscillations in the atmospheric sector by looking for ve appearance at the Far Detector. The observation of ve appearance, tantamount to establishing a non-zero value of the θ13 mixing angle, opens the way to studies of CP violation in the leptonic sector, the neutrino spectral mass pattern ordering and neutrino oscillations in matter, the driving motivations of the next generation of neutrino experiments. In this thesis, we study the MINOS potential for measuring θ13 in the context of the MINOS Mock Data Challenge using a multivariate discriminant analysis method. We show the method's validity in the application to ve event classification and background identification, as well as in its ability to identify a ve signal in a Mock Data sample generated with undisclosed parameters. An independent shower reconstruction method based on three-dimensional hit matching and clustering was developed, providing several useful discriminator variables used in the multivariate analysis method. We also demonstrate that within 2 years of running, MINOS has the potential to improve the current best limit on θ13, from the CHOOZ experiment, by a factor of 2.

  2. A Search for nu_mu to nu_e oscillations in the NOMAD experiment

    CERN Document Server

    Godley, Andrew R

    2000-01-01

    The NOMAD experiment is a neutrino oscillation experiment. capable of identifying Vμ, -Vμ, Ve, -Ve and Vt for use in oscillation analyses. A search for Vμ --> Ve oscillations is conducted, emphasising the development of two separate beam simulators, to provide the background, (no oscillation), lie signal. Both beam descriptions include fits to the results of the SPY experiment that measured hadron production from a 450 GeV proton beam on beryllium target. An independent analysis of the raw SPY data to produce the particle yield is reported. A series of criteria are described for the selection and classification of neutrino events. These produce the data samples necessary for both tuning the beam simulation and determining the oscillation signal. The development of a GEANT and FLUKA based Monte Carlo beam simulator is presented; providing good agreement to the measured neutrino beam. This simulation method has sizeable variations depending on the beamline geometry, which is not knonm precisely. This causes ...

  3. Neutrino oscillations make their first appearance in OPERA

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    1400 metres underground in the INFN Gran Sasso Laboratory, the Opera experiment has just observed its first candidate for neutrino oscillation – the phenomenon that confirms that neutrinos have mass. It is the first time that an experiment has observed the direct appearance of the new type of neutrinos produced in the oscillation. Opera uses a dedicated beam produced at CERN’s Super Proton Synchrotron (SPS).   Tracks of first candidate event observed by the OPERA experiment. Neutrinos, abundant in cosmic rays, are involved in several of the nuclear reactions that take place in the Sun, and also in radioactive decays. Numerous as they are, they continue to hold many secrets for scientists. One is the fact that the three types of neutrinos—electron, muon and tau neutrinos—can change into each another. This physical phenomenon, known as neutrino ‘oscillations’, was originally described in an article by Bruno Pontecorvo and Vla...

  4. Feasibility of 81Br(nu,e-)81Kr solar neutrino experiment

    International Nuclear Information System (INIS)

    Hurst, G.S.; Allman, S.L.; Chen, C.H.; Kramer, S.D.; Thomson, J.O.; Cleveland, B.

    1985-05-01

    Several ingenious solutions have been offered for the solar neutrino problem - a defect in the solar model, the appearance of a new type of neutrino physics, the sun is no longer burning, etc. The range of these proffered solutions stresses the need for a new experiment to study the sun. The modern pulsed laser now makes possible a new solar neutrino test which examines an independent neutrino source in the sun. A recently proposed experiment would use the reaction 81 Br(nu,e - ) 81 Kr to measure the flux of 7 Be neutrinos from the sun. When 7 Be decays by electron capture to make 7 Li, a neutrino is emitted at 0.862 MeV and the flux of these on the earth is about 4 x 10 9 cm -2 s -1 , according to the standard model. Therefore, an experiment based on 81 Br(nu,e - ) 81 Kr which is sensitive to these lower energy neutrinos would be of fundamental importance. To first order, the chlorine experiment detects the 8 B neutrinos while bromine detects the much more abundant 7 Be neutrino source. In practice, the proposed bromine experiment would be very similar to the chlorine radiochemical experiment, except that 81 Kr with a half-life of 2 x 10 5 years cannot be counted by decay methods. With an experiment of about the same volume as the chlorine experiment (380 m 3 ) filled with CH 2 Br 2 , the model predicts about 2 atoms of 81 Kr per day. The bromine experiment depends entirely on the RIS method, implemented with pulsed lasers, for its success. 10 refs., 3 figs

  5. Proposed solar neutrino experiment using 81Br(nu,e-)81Kr

    International Nuclear Information System (INIS)

    Hurst, G.S.; Chen, C.H.; Kramer, S.D.; Allman, S.L.

    1984-12-01

    It has now been shown that it is feasible to measure the 7 Be neutrino source in the sun by using the reaction 81 Br(nu,e - ) 81 Kr in a radiochemical experiment. Such an experiment would be quite similar to the Davis, Cleveland, and Rowley method for measuring the 8 B neutrino using 37 Cl(nu,e - ) 37 Ar except that the resonance ionization spectroscopy (RIS) method (instead of decay counting) would be employed to count the 2 x 10 5 -yr 81 Kr atoms

  6. Measurement of the Absolute Branching Fraction for Lambda(+)(c) -> Lambda e(+)nu(e)

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M.N.; Ai, X.C.; Albayrak, O.; Albrecht, M.; Ambrose, D.J.; Amorose, A.; Haddadi, Z.; Kalantar-Nayestanaki, Nasser; Kavatsyuk, M.; Messchendorp, J.G; Tiemens, M.

    2015-01-01

    We report the first measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda e(+)nu(e). This measurement is based on 567 pb(-1) of e(+)e(-) annihilation data produced at root s = 4.599 GeV, which is just above the Lambda(+)(c)Lambda(-)(c) threshold. The data were collected with the

  7. Study of the appearance of oscillating electron neutrinos issued from muon neutrino beam in the K2K experiment

    International Nuclear Information System (INIS)

    Argyriades, J.

    2006-05-01

    The work presented in this thesis has been done in the K2K experiment. His principle consists in the use of a beam of muon neutrinos, which flux has been measured at short and long distances. Those data enable us to study the effects of neutrino oscillation, particularly by measuring ν μ disappearance. Although this is not an appearance experiment, electronic neutrinos oscillation has been searched. In spite of no signal of appearance, this study enables to constrain oscillation parameters (Δm 23 2 , sin 2 2θ 13 ). With one event for 1,07 expected event from background, the exclusion area edges are close to the best actual limits, provided by Chooz experiment. By setting Δm 23 2 .= 2,8.10 -3 eV 2 , a limit at 90% confident level is reached: sin 2 2θ 13 < 0,2. (author)

  8. The OPERA experiment. ν{sub μ}→ν{sub τ} oscillation discovered in appearance mode

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Benjamin [Universitaet Hamburg, Institut fuer Experimentalphysik (Germany); Collaboration: OPERA-Hamburg-Collaboration

    2016-07-01

    The primary goal of the OPERA long-baseline neutrino oscillation experiment is the first direct detection of ν{sub μ}→ν{sub τ} oscillations. The hybrid OPERA detector consists of a large-mass target made from lead and photo emulsions - providing micrometric resolution - and electronic detector parts for online readout. It is located in the LNGS underground laboratory, at a distance of 730 km from the SPS at CERN, where the CNGS ν{sub μ} beam is produced. The measurement of ν{sub τ} appearance relies on the detection of the decay of τ leptons which are created in ν{sub τ} charged current reactions. Data acquisition lasted from 2008 to 2012. With the collected data the OPERA experiment discovered ν{sub τ} appearance in the CNGS neutrino beam with a significance of 5.1 σ. This poster will give an overview about the OPERA experiment and the discovery of τ neutrino appearance in the CNGS neutrino beam.

  9. Search of neutrino oscillations by ντ appearance with τ decay in the muonic channel in OPERA experiment

    International Nuclear Information System (INIS)

    Tran, N.T.

    2010-10-01

    Neutrino oscillations, based on a change of flavor state of a neutrino during its propagation, can explain the deficits observed on solar and atmospheric neutrinos and provide some interesting indications for physics beyond the Standard Model by studying the mixing angles and the hierarchy of neutrino mass. The OPERA experiment is the first experiment designed to observe the appearance of a ν τ by the oscillation of the ν μ to ν τ in the CNGS beam from CERN to Gran Sasso. OPERA is a hybrid detector combining both the technique of an on time electronic detection and the technique of emulsion cloud chamber (ECC). The ECC detector is a passive detector (target) of 150.000 bricks, each one consisting of sheets of lead, used as target, alternating with nuclear photographic emulsions whose accuracy of track reconstruction is about one micron. The detector also includes two spectrometers with magnetized iron plates 5 cm thick alternating with RPC (resistive plate chamber) associated with six sets of drift tubes for the measurement of the charge and momentum of the muon. It includes also a Veto plane used for rejection of particles coming outside the target. This detector simultaneously allows a high spatial resolution and a large target mass which are two very conditions necessary for collecting charged current neutrino interactions from oscillated ν τ and observing the decay topology of τ. This thesis presents a study on tau decay in the muonic channel. It has contributed to 1) the development of an algorithm for the selection of the neutrino interactions in the target, 2) the studies on the muon identification in electronic detectors and the connection of its trace with those reconstructed in the emulsions, which represent a fundamental point both for the tau signal identification as the rejection of charmed background, 3) the development of a neural network to discriminate the signal from the charmed background regardless of the muon identification in

  10. Search for the weak decays J/psi -> D-s(()*()-) e(+)nu(e) + c.c.

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Ferroli, R. Baldini; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Chu, Y. P.; Cibinetto, G.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fu, C. D.; Gao, Q.; Gao, Y.; Garzia, I.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, T.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S; Han, Y. L.; Harris, F. A.; He, K. L.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, H. P.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, L. W.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kuehn, W.; Kupsc, A.; Lai, W.; Lange, J. S.; Lara, M.; Larin, P.; Li, C. H.; Li, Cheng; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, R. Q.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. N.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Moeini, H.; Morales, C. Morales; Moriya, K.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pu, Y. N.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ren, H. L.; Ripka, M.; Rong, G.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrie, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Spruck, B.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Toth, D.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, W.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, Li; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.

    2014-01-01

    Using a sample of 2.25 x 10(8) J/psi events collected with the BESIII detector at the BEPCII collider, we search for the J/psi semileptonic weak decay J/psi -> D-s(-) e(+)nu(e) +c.c. with a much higher sensitivity than previous searches. We also perform the first search for J/psi -> D-s(*-) e(+)

  11. Search for neutrino oscillations at the palo verde nuclear reactors

    Science.gov (United States)

    Boehm; Busenitz; Cook; Gratta; Henrikson; Kornis; Lawrence; Lee; McKinny; Miller; Novikov; Piepke; Ritchie; Tracy; Vogel; Wang; Wolf

    2000-04-24

    We report on the initial results from a measurement of the antineutrino flux and spectrum at a distance of about 800 m from the three reactors of the Palo Verde Nuclear Generating Station using a segmented gadolinium-loaded scintillation detector. We find that the antineutrino flux agrees with that predicted in the absence of oscillations excluding at 90% C.L. nu;(e)-nu;(x) oscillations with Deltam(2)>1.12x10(-3) eV(2) for maximal mixing and sin (2)2straight theta>0.21 for large Deltam(2). Our results support the conclusion that the atmospheric neutrino oscillations observed by Super-Kamiokande do not involve nu(e).

  12. Measurement of the absolute branching fraction of D-vertical bar -> (K)over-bar(0)e(vertical bar) nu(e) via (K)over-bar(0) -> pi(0)pi(0)

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Ferroli, R. Baldini; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettonin, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Caleaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fedorov, O.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Y.; Huang, Z. L.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolc, O. B.; Kopf, B.; Kornicer, M.; Kupse, A.; Kuehn, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Y. B.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales, C. Morales; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrie, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shi, M.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuangig, J.; Zotti, L.; Zou, B. S.; Zou, J. H.

    2016-01-01

    By analyzing 2.93 fb(-1) data collected at the center-of-mass energy root s = 3.773 GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay D+ -> (K) over bar (0)e(+)nu(e) to be B(D (+) -> (K) over bar (0)e(+)nu(e)) = (8.59 +/- 0.14 +/- 0.21)% using (K)

  13. The search for neutrino oscillations in the appearance mode nu/sub μ/ → nu/sub e/ for neutrino energies near the muon threshold

    International Nuclear Information System (INIS)

    Huang, Ying-Chiang.

    1986-12-01

    To investigate the possibility of neutrino oscillation, a search for the exclusive mode, nu/sub μ/ → nu/sub e/, was performed at LAMPF. The reactions studied were nu/sub μ/ + C → μ - + X; μ - → e - + anti nu/sub e/ + nu/sub μ/, and nu/sub e/ + C → e - + X (if nu/sub μ/ → nu/sub e/). The detector was located at an effective distance of 20 m from the water target. The beam was composed primarily of muon-neutrinos from pion decay, and the neutrino flux (of mean energy 150 MeV) was computed to be 6.2 x 10 5 nu/cm 2 -sec for 20 μA of proton beam on our target. We saw no evidence for oscillations, and were able to set upper limits sin 2 (2Θ) ≤ 8.8 x 10 -3 (90% C.L.) (in the limit of large Δm 2 ) and Δm 2 sin(2Θ) ≤ 0.59 eV 2 (in the limit of small Δm 2 )

  14. Final NOMAD results on {nu}{sub {mu}}{yields}{nu}{sub {tau}} and {nu}{sub e}{yields}{nu}{sub {tau}} oscillations including a new search for {nu}{sub {tau}} appearance using hadronic {tau} decays

    Energy Technology Data Exchange (ETDEWEB)

    Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P.W.; Cavasinni, V.; Cervera-Villanueva, A.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Degaudenzi, H.; Del Prete, T.; De Santo, A.; Dignan, T.; Di Lella, L.; Couto e Silva, E. do; Dumarchez, J.; Ellis, M.; Feldman, G.J.; Ferrari, R.; Ferrere, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Goessling, C.; Gouanere, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kustov, D.; Kuznetsov, V.E.; Lacaprara, S.; Lachaud, C.; Lakic, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J.-M.; Linssen, L.; Ljubic, A.; Long, J.; Lupi, A.; Marchionni, A.; Martelli, F.; Mechain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mezzetto, M.; Mishra, S.R.; Moorhead, G.F.; Naumov, D.; Nedelec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L.S.; Pennacchio, E.; Pessard, H.; Petti, R. E-mail: roberto.petti@cern.ch; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Popov, B.; Poulsen, C.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Sevior, M.; Sillou, D.; Soler, F.J.P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipc, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G.N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S.N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K.E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.[and others

    2001-09-17

    Results from the {nu}{sub {tau}} appearance search in a neutrino beam using the full NOMAD data sample are reported. A new analysis unifies all the hadronic {tau} decays, significantly improving the overall sensitivity of the experiment to oscillations. The 'blind analysis' of all topologies yields no evidence for an oscillation signal. In the two-family oscillation scenario, this sets a 90% CL allowed region in the sin{sup 2}2{theta}{sub {mu}}{sub {tau}}-{delta}m{sup 2} plane which includes sin{sup 2}2{theta}{sub {mu}}{sub {tau}}<3.3x10{sup -4} at large {delta}m{sup 2} and {delta}m{sup 2}< 0.7 eV{sup 2}/c{sup 4} at sin{sup 2}2{theta}{sub {mu}}{sub {tau}}=1. The corresponding contour in the {nu}{sub e}{yields}{nu}{sub {tau}} oscillation hypothesis results in sin{sup 2}2{theta}{sub e{tau}}<1.5x10{sup -2} at large {delta}m{sup 2} and {delta}m{sup 2}<5.9 eV{sup 2}/c{sup 4} at sin{sup 2}2{theta}{sub e{tau}}=1. We also derive limits on effective couplings of the {tau} lepton to {nu}{sub {mu}} or {nu}{sub e}.

  15. Bosonic construction of the Lie algebras of some non-compact groups appearing in supergravity theories and their oscillator-like unitary representations

    International Nuclear Information System (INIS)

    Guenaydin, M.; Saclioglu, C.

    1981-06-01

    We give a construction of the Lie algebras of the non-compact groups appearing in four dimensional supergravity theories in terms of boson operators. Our construction parallels very closely their emergence in supergravity and is an extension of the well-known construction of the Lie algebras of the non-compact groups Sp(2n,IR) and SO(2n) from boson operators transforming like a fundamental representation of their maximal compact subgroup U(n). However this extension is non-trivial only for n >= 4 and stops at n = 8 leading to the Lie algebras of SU(4) x SU(1,1), SU(5,1), SO(12) and Esub(7(7)). We then give a general construction of an infinite class of unitary irreducible representations of the respective non-compact groups (except for Esub(7(7)) and SO(12) obtained from the extended construction). We illustrate our construction with the examples of SU(5,1) and SO(12). (orig.)

  16. Study of the appearance of oscillating electron neutrinos issued from muon neutrino beam in the K2K experiment; Etude de l'apparition de neutrinos electroniques oscillant a partir de neutrinos muoniques du faisceau de l'experience K2K

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J

    2006-05-15

    The work presented in this thesis has been done in the K2K experiment. His principle consists in the use of a beam of muon neutrinos, which flux has been measured at short and long distances. Those data enable us to study the effects of neutrino oscillation, particularly by measuring {nu}{sub {mu}} disappearance. Although this is not an appearance experiment, electronic neutrinos oscillation has been searched. In spite of no signal of appearance, this study enables to constrain oscillation parameters ({delta}m{sub 23}{sup 2}, sin{sup 2}2{theta}{sub 13}). With one event for 1,07 expected event from background, the exclusion area edges are close to the best actual limits, provided by Chooz experiment. By setting {delta}m{sub 23}{sup 2}.= 2,8.10{sup -3} eV{sup 2}, a limit at 90% confident level is reached: sin{sup 2}2{theta}{sub 13} < 0,2. (author)

  17. Possible Tau Appearance Experiment with Atmospheric Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor

    1999-12-27

    We suggest an experimental measurement that could detect the appearance of tau neutrinos due to {nu}{sub {mu}}{yields}{nu}{sub {tau}} oscillations of atmospheric neutrinos by measuring the energy spectra of neutrino induced showers. {tau} neutrinos deposit a large fraction of their energy in showers generated by {nu}{sub {tau}} charge current interactions and the subsequent {tau} -lepton decay. The appearance of {nu}{sub {tau}} will enhance the spectrum of neutrino induced showers in energy ranges corresponding to the neutrino oscillation parameters. A shower rate lower than the ''no oscillation'' prediction is an indication for {nu}{sub {mu}}{yields}{nu}{sub s} oscillations. (c) 1999 The American Physical Society.

  18. Density-wave oscillations

    International Nuclear Information System (INIS)

    Belblidia, L.A.; Bratianu, C.

    1979-01-01

    Boiling flow in a steam generator, a water-cooled reactor, and other multiphase processes can be subject to instabilities. It appears that the most predominant instabilities are the so-called density-wave oscillations. They can cause difficulties for three main reasons; they may induce burnout; they may cause mechanical vibrations of components; and they create system control problems. A comprehensive review is presented of experimental and theoretical studies concerning density-wave oscillations. (author)

  19. Observation of Quasichanneling Oscillations

    International Nuclear Information System (INIS)

    Wistisen, T. N.; Mikkelsen, R. E.; Uggerhoj, University I.; Wienands, University; Markiewicz, T. W.

    2017-01-01

    Here, we report on the first experimental observations of quasichanneling oscillations, recently seen in simulations and described theoretically. Although above-barrier particles penetrating a single crystal are generally seen as behaving almost as in an amorphous substance, distinct oscillation peaks nevertheless appear for particles in that category. The quasichanneling oscillations were observed at SLAC National Accelerator Laboratory by aiming 20.35 GeV positrons and electrons at a thin silicon crystal bent to a radius of R = 0.15 m, exploiting the quasimosaic effect. For electrons, two relatively faint quasichanneling peaks were observed, while for positrons, seven quasichanneling peaks were clearly identified.

  20. Oscillator monitor

    International Nuclear Information System (INIS)

    McNeill, G.A.

    1981-01-01

    Present high-speed data acquisition systems in nuclear diagnostics use high-frequency oscillators to provide timing references for signals recorded on fast, traveling-wave oscilloscopes. An oscillator's sinusoidal wave shape is superimposed on the recorded signal with each cycle representing a fixed time increment. During data analysis the sinusoid is stripped from the signal, leaving a clean signal shape with known timing. Since all signal/time relationships are totally dependant upon working oscillators, these critical devices must have remote verification of proper operation. This manual presents the newly-developed oscillator monitor which will provide the required verification

  1. From excitability to oscillations

    DEFF Research Database (Denmark)

    Postnov, D. E.; Neganova, A. Y.; Jacobsen, J. C. B.

    2013-01-01

    One consequence of cell-to-cell communication is the appearance of synchronized behavior, where many cells cooperate to generate new dynamical patterns. We present a simple functional model of vasomotion based on the concept of a two-mode oscillator with dual interactions: via relatively slow dif...

  2. Chromospheric oscillations

    NARCIS (Netherlands)

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

    1995-01-01

    We show results from SO/Sacramento Peak data to discuss three issues: (i)--the spatial occurrence of chromospheric 3--min oscillations; (ii)--the validity of Ca II H&K line-center Doppler Shift measurements; (iii)--the signi ?cance of oscillation power and phase at frequencies above 10 mHz.

  3. Inverted oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Yuce, C [Physics Department, Anadolu University, Eskisehir (Turkey); Kilic, A [Physics Department, Anadolu University, Eskisehir (Turkey); Coruh, A [Physics Department, Sakarya University, Sakarya (Turkey)

    2006-07-15

    The inverted harmonic oscillator problem is investigated quantum mechanically. The exact wavefunction for the confined inverted oscillator is obtained and it is shown that the associated energy eigenvalues are discrete, and the energy is given as a linear function of the quantum number n.

  4. Oscillating acoustic streaming jet

    International Nuclear Information System (INIS)

    Moudjed, Brahim; Botton, Valery; Henry, Daniel; Millet, Severine; Ben Hadid, Hamda; Garandet, Jean-Paul

    2014-01-01

    The present paper provides the first experimental investigation of an oscillating acoustic streaming jet. The observations are performed in the far field of a 2 MHz circular plane ultrasound transducer introduced in a rectangular cavity filled with water. Measurements are made by Particle Image Velocimetry (PIV) in horizontal and vertical planes near the end of the cavity. Oscillations of the jet appear in this zone, for a sufficiently high Reynolds number, as an intermittent phenomenon on an otherwise straight jet fluctuating in intensity. The observed perturbation pattern is similar to that of former theoretical studies. This intermittently oscillatory behavior is the first step to the transition to turbulence. (authors)

  5. Current Status of the MiniBooNE Experiment

    OpenAIRE

    Ray, H.; collaboration, for the MiniBooNE

    2004-01-01

    MiniBooNE is an experiment designed to refute or confirm the LSND anti-nu_mu -> anti-nu_e oscillation result. MiniBooNE will look for oscillations of nu_mu -> nu_e in a closed-box appearance analysis. MiniBooNE began collecting data in 2002, and is expected to continue data taking through 2005. Current MiniBooNE results are presented.

  6. Chemical Oscillations

    Indian Academy of Sciences (India)

    IMTECH),. Chandigarh. Praveen Kumar is pursuing his PhD in chemical dynamics at. Panjab University,. Chandigarh. Keywords. Chemical oscillations, autoca-. talYSis, Lotka-Volterra model, bistability, hysteresis, Briggs-. Rauscher reaction.

  7. Chemical Oscillations

    Indian Academy of Sciences (India)

    the law of mass-action that every simple reaction approaches ... from thermodynamic equilibrium. Such oscillating systems cor- respond to thermodynamically open systems. .... experimentally observable, and the third is always unstable.

  8. CT appearance of splenosis

    Energy Technology Data Exchange (ETDEWEB)

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-12-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT.

  9. CT appearance of splenosis

    International Nuclear Information System (INIS)

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-01-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT

  10. On Multiple Appearances

    DEFF Research Database (Denmark)

    Bork Petersen, Franziska

    2012-01-01

    reduction and epoché to focus on how dancing bodies appear in a stage context. To test these tools’ ability to explore dancing bodies from a third-person perspective, I analyse the Danish choreographer Kitt Johnson’s solo performance Drift (2011) - focussing on her shifting physical appearance. While...... phenomenology helps me to describe the multiple and radically different guises that Johnson assumes in her piece, my analysis, ultimately, does not aim to distil a truer, more real being from her appearances as is often the case in phenomenological philosophy. I complement my analytical approach...... with the Deleuzian notion of becoming animal and suggest that Johnson stages what could, in Judith Butler’s terms, be called a critical contingency of bodily appearance....

  11. Nonlinear oscillations

    CERN Document Server

    Nayfeh, Ali Hasan

    1995-01-01

    Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim

  12. Wedgelet Enhanced Appearance Models

    DEFF Research Database (Denmark)

    Darkner, Sune; Larsen, Rasmus; Stegmann, Mikkel Bille

    2004-01-01

    Statistical region-based segmentation methods such as the Active Appearance Model (AAM) are used for establishing dense correspondences in images based on learning the variation in shape and pixel intensities in a training set. For low resolution 2D images correspondences can be recovered reliably....... The wedgelet regression trees employed are based on triangular domains and estimated using cross validation. The wedgelet regression trees are functional descriptions of the intensity information and serve to 1) reduce noise and 2) produce a compact textural description. The wedgelet enhanced appearance model...

  13. Measurement of electron neutrino appearance with the MINOS experiment

    International Nuclear Information System (INIS)

    Boehm, Joshua Adam Alpern

    2009-01-01

    MINOS is a long-baseline two-detector neutrino oscillation experiment that uses a high intensity muon neutrino beam to investigate the phenomena of neutrino oscillations. By measuring the neutrino interactions in a detector near the neutrino source and again 735 km away from the production site, it is possible to probe the parameters governing neutrino oscillation. The majority of the ν μ oscillate to ν τ but a small fraction may oscillate instead to ν e . This thesis presents a measurement of the ν e appearance rate in the MINOS far detector using the first two years of exposure. Methods for constraining the far detector backgrounds using the near detector measurements is discussed and a technique for estimating the uncertainty on the background and signal selection are developed. A 1.6σ excess over the expected background rate is found providing a hint of ν e appearance.

  14. Tuberculous peritonitis: CT appearance

    International Nuclear Information System (INIS)

    Hanson, R.D.; Hunter, T.B.

    1985-01-01

    Rare, sporadic cases of tuberculous peritonitis do occur in the United States and other advanced countries. Because there are few descriptions of the CT appearance of the peritoneal forms of tuberculous (TB), this report illustrates a case of tuberculous peritonitis with prominent CT findings and discusses the differentiation of this entity from other, more common diseases

  15. Texture Enhanced Appearance Models

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Stegmann, Mikkel Bille; Darkner, Sune

    2007-01-01

    Statistical region-based registration methods such as the Active Appearance Model (AAM) are used for establishing dense correspondences in images. At low resolution, images correspondences can be recovered reliably in real-time. However, as resolution increases this becomes infeasible due...... representation are superior to wavelet representations at high dimensionality-reduction rates. At low reduction rates an edge enhanced wavelet representation provides better segmentation accuracy than the full standard AAM model....

  16. Musculoskeletal infections: ultrasound appearances

    Energy Technology Data Exchange (ETDEWEB)

    Chau, C.L.F. [Department of Radiology, North District Hospital, NTEC, Fanling, NT, Hong Kong (China)]. E-mail: c8681@yahoo.com; Griffith, J.F. [Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, NTEC, Shatin, NT, Hong Kong (China)

    2005-02-01

    Musculoskeletal infections are commonly encountered in clinical practice. This review will discuss the ultrasound appearances of a variety of musculoskeletal infections such as cellulitis, infective tenosynovitis, pyomyositis, soft-tissue abscesses, septic arthritis, acute and chronic osteomyelitis, and post-operative infection. The peculiar sonographic features of less common musculoskeletal infections, such as necrotizing fasciitis, and rice body formation in atypical mycobacterial tenosynovitis, and bursitis will also be presented.

  17. Musculoskeletal infections: ultrasound appearances

    International Nuclear Information System (INIS)

    Chau, C.L.F.; Griffith, J.F.

    2005-01-01

    Musculoskeletal infections are commonly encountered in clinical practice. This review will discuss the ultrasound appearances of a variety of musculoskeletal infections such as cellulitis, infective tenosynovitis, pyomyositis, soft-tissue abscesses, septic arthritis, acute and chronic osteomyelitis, and post-operative infection. The peculiar sonographic features of less common musculoskeletal infections, such as necrotizing fasciitis, and rice body formation in atypical mycobacterial tenosynovitis, and bursitis will also be presented

  18. Realistic Material Appearance Modelling

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Filip, Jiří; Hatka, Martin

    2010-01-01

    Roč. 2010, č. 81 (2010), s. 13-14 ISSN 0926-4981 R&D Projects: GA ČR GA102/08/0593 Institutional research plan: CEZ:AV0Z10750506 Keywords : bidirectional texture function * texture modelling Subject RIV: BD - Theory of Information http:// library .utia.cas.cz/separaty/2010/RO/haindl-realistic material appearance modelling.pdf

  19. Topological phase in two flavor neutrino oscillations

    International Nuclear Information System (INIS)

    Mehta, Poonam

    2009-01-01

    We show that the phase appearing in neutrino flavor oscillation formulae has a geometric and topological contribution. We identify a topological phase appearing in the two flavor neutrino oscillation formula using Pancharatnam's prescription of quantum collapses between nonorthogonal states. Such quantum collapses appear naturally in the expression for appearance and survival probabilities of neutrinos. Our analysis applies to neutrinos propagating in vacuum or through matter. For the minimal case of two flavors with CP conservation, our study shows for the first time that there is a geometric interpretation of the neutrino oscillation formulae for the detection probability of neutrino species.

  20. Color appearance in stereoscopy

    Science.gov (United States)

    Gadia, Davide; Rizzi, Alessandro; Bonanomi, Cristian; Marini, Daniele; Galmonte, Alessandra; Agostini, Tiziano

    2011-03-01

    The relationship between color and lightness appearance and the perception of depth has been studied since a while in the field of perceptual psychology and psycho-physiology. It has been found that depth perception affects the final object color and lightness appearance. In the stereoscopy research field, many studies have been proposed on human physiological effects, considering e.g. geometry, motion sickness, etc., but few has been done considering lightness and color information. Goal of this paper is to realize some preliminar experiments in Virtual Reality in order to determine the effects of depth perception on object color and lightness appearance. We have created a virtual test scene with a simple 3D simultaneous contrast configuration. We have created three different versions of this scene, each with different choices of relative positions and apparent size of the objects. We have collected the perceptual responses of several users after the observation of the test scene in the Virtual Theater of the University of Milan, a VR immersive installation characterized by a semi-cylindrical screen that covers 120° of horizontal field of view from an observation distance of 3.5 m. We present a description of the experiments setup and procedure, and we discuss the obtained results.

  1. Uterine Leiomyoma: Hysterosalpingographic Appearances

    Directory of Open Access Journals (Sweden)

    Firoozeh Ahmadi

    2008-01-01

    Full Text Available Uterine leiomyoma is the most common benign tumor of genital tract. The etiology of myomasis unknown. Leiomyoma shows a broad spectrum of radiographic appearances depending on thenumber, size, and location of the tumor. The diagnostic method for uterine leiomyomas is basedprimarily on the clinical situation. Despite of the varied diagnostic options such as; transvaginalsonography, sonohysterography, hysteroscopy, laparoscopy and MRI; hysterosalpingography isstill one of the valuable imaging methods for identification of uterine leiomyoma.The various features of the proved leiomyoma are illustrated in this pictorial review. The incidence,risk factors and clinical features will also be discussed briefly.

  2. Wavelet Enhanced Appearance Modelling

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Forchhammer, Søren; Cootes, Timothy F.

    2004-01-01

    Generative segmentation methods such as the Active Appearance Models (AAM) establish dense correspondences by modelling variation of shape and pixel intensities. Alas, for 3D and high-resolution 2D images typical in medical imaging, this approach is rendered infeasible due to excessive storage......-7 wavelets on face images have shown that segmentation accuracy degrades gracefully with increasing compression ratio. Further, a proposed weighting scheme emphasizing edges was shown to be significantly more accurate at compression ratio 1:1, than a conventional AAM. At higher compression ratios the scheme...

  3. Nonlocal synchronization in nearest neighbour coupled oscillators

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Elgazzar, A.S.; Cerdeira, H.A.

    2002-02-01

    We investigate a system of nearest neighbour coupled oscillators. We show that the nonlocal frequency synchronization, that might appear in such a system, occurs as a consequence of the nearest neighbour coupling. The power spectra of nonadjacent oscillators shows that there is no complete coincidence between all frequency peaks of the oscillators in the nonlocal cluster, while the peaks for neighbouring oscillators approximately coincide even if they are not yet in a cluster. It is shown that nonadjacent oscillators closer in frequencies, share slow modes with their adjacent oscillators which are neighbours in space. It is also shown that when a direct coupling between non-neighbours oscillators is introduced explicitly, the peaks of the spectra of the frequencies of those non-neighbours coincide. (author)

  4. Saliency Changes Appearance

    Science.gov (United States)

    Kerzel, Dirk; Schönhammer, Josef; Burra, Nicolas; Born, Sabine; Souto, David

    2011-01-01

    Numerous studies have suggested that the deployment of attention is linked to saliency. In contrast, very little is known about how salient objects are perceived. To probe the perception of salient elements, observers compared two horizontally aligned stimuli in an array of eight elements. One of them was salient because of its orientation or direction of motion. We observed that the perceived luminance contrast or color saturation of the salient element increased: the salient stimulus looked even more salient. We explored the possibility that changes in appearance were caused by attention. We chose an event-related potential indexing attentional selection, the N2pc, to answer this question. The absence of an N2pc to the salient object provides preliminary evidence against involuntary attentional capture by the salient element. We suggest that signals from a master saliency map flow back into individual feature maps. These signals boost the perceived feature contrast of salient objects, even on perceptual dimensions different from the one that initially defined saliency. PMID:22162760

  5. Electronically tunable RC sinusoidal oscillators

    International Nuclear Information System (INIS)

    Florescu, Valeriu

    2008-01-01

    This paper presents two types of active configurations for realizing electronically tunable RC sinusoidal oscillators. The type-1 network employs two grounded scaled resistances KR 1 and KR 2 , where K is scaling factor. The frequency of oscillation W 0 is controlled conveniently by adjusting K, since W 0 appears in the form W 0 =1/K √ R 1 C 1 R 2 C 2 . For realizing the scaled resistances, an active configuration is proposed, which realizes KR 1 =R 1 /(1+f(V B )), where f(V B ) denotes a function of a controlling voltage V B . Thus the frequency tuning can be effected by controlling a voltage V B . The type-2 oscillator uses two periodically switched conductances. It is shown that the tuning of oscillation frequency can be done by varying the pulse width-to-period ratio (t/T) of the periodically switched conductances. (author)

  6. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  7. Phase Multistability in Coupled Oscillator Systems

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Postnov, D.E.; Sosnovtseva, Olga

    2003-01-01

    along the orbit of the individual oscillator. Focusing on the mechanisms underlying the appearance of phase multistability, the paper examines a variety of phase-locked patterns. In particular we demonstrate the nested structure of synchronization regions for oscillations with multicrest wave forms...

  8. One dimension harmonic oscillator

    International Nuclear Information System (INIS)

    Cohen-Tannoudji, Claude; Diu, Bernard; Laloe, Franck.

    1977-01-01

    The importance of harmonic oscillator in classical and quantum physics, eigenvalues and eigenstates of hamiltonian operator are discussed. In complement are presented: study of some physical examples of harmonic oscillators; study of stationnary states in the /x> representation; Hermite polynomials; resolution of eigenvalue equation of harmonic oscillator by polynomial method; isotope harmonic oscillator with three dimensions; charged harmonic oscillator in uniform electric field; quasi classical coherent states of harmonic oscillator; eigenmodes of vibration of two coupled harmonic oscillators; vibration modus of a continuous physical system (application to radiation: photons); vibration modus of indefinite linear chain of coupled harmonic oscillators (phonons); one-dimensional harmonic oscillator in thermodynamic equilibrium at temperature T [fr

  9. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...

  10. Oscillations of void lattices

    International Nuclear Information System (INIS)

    Akhiezer, A.I.; Davydov, L.N.; Spol'nik, Z.A.

    1976-01-01

    Oscillations of a nonideal crystal are studied, in which macroscopic defects (pores) form a hyperlattice. It is shown that alongside with acoustic and optical phonons (relative to the hyperlattice), in such a crystal oscillations of the third type are possible which are a hydridization of sound oscillations of atoms and surface oscillations of a pore. Oscillation spectra of all three types were obtained

  11. A road map to solar neutrino fluxe, neutrino oscillation parameters, and tests for new physics

    CERN Document Server

    Bahcall, J N; Bahcall, John N.; Peña-Garay, Carlos

    2003-01-01

    We analyze all available solar and related reactor neutrino experiments, as well as simulated future ^7Be, p-p, pep, and ^8B solar neutrino experiments. We treat all solar neutrino fluxes as free parameters subject to the condition that the total luminosity represented by the neutrinos equals the observed solar luminosity (the `luminosity constraint'). Existing experiments show that the p-p solar neutrino flux is 1.01 + - 0.02 (1 sigma) times the flux predicted by the BP00 standard solar model; the ^7Be neutrino flux is 0.97^{+0.28}_{-0.54} the predicted flux; and the ^8B flux is 1.01 + - 0.06 the predicted flux. The oscillation parameters are: Delta m^2 = 7.3^{+0.4}_{-0.6} 10^{-5} eV^2 and tan^2 theta_{12} = 0.42^{+0.08}_{-0.06}. We evaluate how accurate future experiments must be to determine more precisely neutrino oscillation parameters and solar neutrino fluxes, and to elucidate the transition from vacuum-dominated to matter-dominated oscillations. A future ^7Be nu-e scattering experiment accurate to + -...

  12. Oscillators - a simple introduction

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2013-01-01

    Oscillators are kernel components of electrical and electronic circuits. Discussion of history, mechanisms and design based on Barkhausens observation. Discussion of a Wien Bridge oscillator based on the question: Why does this circuit oscillate ?......Oscillators are kernel components of electrical and electronic circuits. Discussion of history, mechanisms and design based on Barkhausens observation. Discussion of a Wien Bridge oscillator based on the question: Why does this circuit oscillate ?...

  13. Oscillators and Eigenvalues

    DEFF Research Database (Denmark)

    Lindberg, Erik

    1997-01-01

    In order to obtain insight in the nature of nonlinear oscillators the eigenvalues of the linearized Jacobian of the differential equations describing the oscillator are found and displayed as functions of time. A number of oscillators are studied including Dewey's oscillator (piecewise linear wit...... with negative resistance), Kennedy's Colpitts-oscillator (with and without chaos) and a new 4'th order oscillator with hyper-chaos....

  14. Tau appearance in atmospheric neutrino interactions

    International Nuclear Information System (INIS)

    Hall, Lawrence J.; Murayama, Hitoshi

    1998-01-01

    If the correct interpretation of the Super-Kamiokande atmospheric neutrino data is ν μ → ν τ oscillation, the contained data sample should already have more than 10 τ appearance events. We study the challenging task of detecting the τ, focusing on the decay chain τ ± → ρ ± → π ± π 0 in events with quasi-elastic τ production. The background level, which is currently quite uncertain because of a lack of relevant neutral current data, can be measured by the near detector in the K2K experiment. Our estimates of the background suggest that it may be possible to detect τ appearance in Super-Kamiokande with 5-10 years of running

  15. Chaos in generically coupled phase oscillator networks with nonpairwise interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bick, Christian; Ashwin, Peter; Rodrigues, Ana [Centre for Systems, Dynamics and Control and Department of Mathematics, University of Exeter, Exeter EX4 4QF (United Kingdom)

    2016-09-15

    The Kuramoto–Sakaguchi system of coupled phase oscillators, where interaction between oscillators is determined by a single harmonic of phase differences of pairs of oscillators, has very simple emergent dynamics in the case of identical oscillators that are globally coupled: there is a variational structure that means the only attractors are full synchrony (in-phase) or splay phase (rotating wave/full asynchrony) oscillations and the bifurcation between these states is highly degenerate. Here we show that nonpairwise coupling—including three and four-way interactions of the oscillator phases—that appears generically at the next order in normal-form based calculations can give rise to complex emergent dynamics in symmetric phase oscillator networks. In particular, we show that chaos can appear in the smallest possible dimension of four coupled phase oscillators for a range of parameter values.

  16. Chaos in generically coupled phase oscillator networks with nonpairwise interactions.

    Science.gov (United States)

    Bick, Christian; Ashwin, Peter; Rodrigues, Ana

    2016-09-01

    The Kuramoto-Sakaguchi system of coupled phase oscillators, where interaction between oscillators is determined by a single harmonic of phase differences of pairs of oscillators, has very simple emergent dynamics in the case of identical oscillators that are globally coupled: there is a variational structure that means the only attractors are full synchrony (in-phase) or splay phase (rotating wave/full asynchrony) oscillations and the bifurcation between these states is highly degenerate. Here we show that nonpairwise coupling-including three and four-way interactions of the oscillator phases-that appears generically at the next order in normal-form based calculations can give rise to complex emergent dynamics in symmetric phase oscillator networks. In particular, we show that chaos can appear in the smallest possible dimension of four coupled phase oscillators for a range of parameter values.

  17. Measurement of electron neutrino appearance with the MINOS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Joshua Adam Alpern [Harvard Univ., Cambridge, MA (United States)

    2009-05-01

    MINOS is a long-baseline two-detector neutrino oscillation experiment that uses a high intensity muon neutrino beam to investigate the phenomena of neutrino oscillations. By measuring the neutrino interactions in a detector near the neutrino source and again 735 km away from the production site, it is possible to probe the parameters governing neutrino oscillation. The majority of the vμ oscillate to vτ but a small fraction may oscillate instead to ve. This thesis presents a measurement of the ve appearance rate in the MINOS far detector using the first two years of exposure. Methods for constraining the far detector backgrounds using the near detector measurements is discussed and a technique for estimating the uncertainty on the background and signal selection are developed. A 1.6σ excess over the expected background rate is found providing a hint of ve appearance.

  18. Investigation of density-wave oscillation in parallel boiling channels under high pressure

    International Nuclear Information System (INIS)

    Ming Xiao; Xuejun Chen; Mingyuan Zhang

    1992-01-01

    This paper presents experimental results on density-wave instability in parallel boiling channels. Experiments have been done in a high pressure steam-water loop. Different types of two-phase flow instabilities have been observed, including density-wave oscillation, pressure-drop type oscillation, thermal oscillation and secondary density-wave oscillation. The secondary density-wave oscillation appears at very low exit steam quality (less than 0.1) and at the positive portion of Δ P-G curves with both channels' flow rate oscillating in phase. Density-wave oscillation can appear at pressure up to 192 bar and disappear over 207 bar. (6 figures) (Author)

  19. New neutrino oscillation results from NOVA

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Neutrinos oscillate among flavors as they travel because a neutrino of a particular flavor is also a superposition of multiple neutrinos with slightly different masses.  The interferometric nature of oscillations allows these tiny mass differences to be measured, along with the parameters of the PMNS matrix which governs the mixing. However, since neutrinos only interact weakly, a powerful neutrino source and massive detectors are required to measure them. In this talk I will show recently updated results from NOvA, a long-baseline neutrino oscillation experiment at Fermilab with two functionally identical scintillator detectors. I will present measurements of muon neutrino disappearance and electron neutrino appearance, and what constraints those measurements put on the remaining open questions in neutrino oscillations: Is the neutrino mass hierarchy "normal" or "inverted?" Do neutrino oscillations violate CP symmetry? Is the mixing in the atmospheric sector maximal? The recent update includes 50%...

  20. Ovarian metastases: Computed tomographic appearances

    International Nuclear Information System (INIS)

    Megibow, A.J.; Hulnick, D.H.; Bosniak, M.A.; Balthazar, E.J.

    1985-01-01

    Computed tomographic scans of 34 patients with ovarian metastases were reviewed to assess the radiographic appearances and to correlate these with the primary neoplasms. Primary neoplasms were located in the colon (20 patients), breast (six), stomach (five), small bowel (one), bladder (one), and Wilms tumor of the kidney (one). The radiographic appearance of the metastatic lesions could be described as predominantly cystic (14 lesions), mixed (12 lesions), or solid (seven lesions). The cystic and mixed lesions tended to be larger in overall diameter than the solid. The metastases from gastric carcinoma appeared solid in four of five cases. The metastases from the other neoplasms had variable appearances simulating primary ovarian carcinoma

  1. Fast Newton active appearance models

    NARCIS (Netherlands)

    Kossaifi, Jean; Tzimiropoulos, Georgios; Pantic, Maja

    2014-01-01

    Active Appearance Models (AAMs) are statistical models of shape and appearance widely used in computer vision to detect landmarks on objects like faces. Fitting an AAM to a new image can be formulated as a non-linear least-squares problem which is typically solved using iterative methods. Owing to

  2. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  3. Umbral oscillations as a probe of sunspot

    International Nuclear Information System (INIS)

    Abdelatif, T.E.H.

    1985-01-01

    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

  4. Entanglement of higher-derivative oscillators in holographic systems

    Energy Technology Data Exchange (ETDEWEB)

    Dimov, Hristo, E-mail: h_dimov@phys.uni-sofia.bg [Department of Physics, Sofia University, 5 J. Bourchier Blvd., 1164 Sofia (Bulgaria); Mladenov, Stefan, E-mail: smladenov@phys.uni-sofia.bg [Department of Physics, Sofia University, 5 J. Bourchier Blvd., 1164 Sofia (Bulgaria); Rashkov, Radoslav C., E-mail: rash@phys.uni-sofia.bg [Department of Physics, Sofia University, 5 J. Bourchier Blvd., 1164 Sofia (Bulgaria); Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstr. 8–10, 1040 Vienna (Austria); Vetsov, Tsvetan, E-mail: vetsov@phys.uni-sofia.bg [Department of Physics, Sofia University, 5 J. Bourchier Blvd., 1164 Sofia (Bulgaria)

    2017-05-15

    We study the quantum entanglement of coupled Pais–Uhlenbeck oscillators using the formalism of thermo-field dynamics. The entanglement entropy is computed for the specific cases of two and a ring of N coupled Pais–Uhlenbeck oscillators of fourth order. It is shown that the entanglement entropy depends on the temperatures, frequencies and coupling parameters of the different degrees of freedom corresponding to harmonic oscillators. We also make remarks on the appearance of instabilities of higher-derivative oscillators in the context of AdS/CFT correspondence. Finally, we advert to the information geometry theory by calculating the Fisher information metric for the considered system of coupled oscillators.

  5. Automatic Oscillating Turret.

    Science.gov (United States)

    1981-03-01

    Final Report: February 1978 ZAUTOMATIC OSCILLATING TURRET SYSTEM September 1980 * 6. PERFORMING 01G. REPORT NUMBER .J7. AUTHOR(S) S. CONTRACT OR GRANT...o....e.... *24 APPENDIX P-4 OSCILLATING BUMPER TURRET ...................... 25 A. DESCRIPTION 1. Turret Controls ...Other criteria requirements were: 1. Turret controls inside cab. 2. Automatic oscillation with fixed elevation to range from 20* below the horizontal to

  6. Neutrino oscillations in matter

    International Nuclear Information System (INIS)

    Mikheyev, S.P.; Smirnov, A.Yu.

    1986-01-01

    In this paper we describe united formalism of ν-oscillations for different regimes, which is immediate generalization of vacuum oscillations theory. Adequate graphical representation of this formalism is given. We summarize main properties of ν-oscillations for different density distributions. (orig./BBOE)

  7. The colpitts oscillator family

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, A.

    A tutorial study of the Colpitts oscillator family defined as all oscillators based on a nonlinear amplifier and a three- terminal linear resonance circuit with one coil and two capacitors. The original patents are investigated. The eigenvalues of the linearized Jacobian for oscillators based...

  8. Evolution, Appearance, and Occupational Success

    Directory of Open Access Journals (Sweden)

    Anthony C. Little

    2012-12-01

    Full Text Available Visual characteristics, including facial appearance, are thought to play an important role in a variety of judgments and decisions that have real occupational outcomes in many settings. Indeed, there is growing evidence suggesting that appearance influences hiring decisions and even election results. For example, attractive individuals are more likely to be hired, taller men earn more, and the facial appearance of candidates has been linked to real election outcomes. In this article, we review evidence linking physical appearance to occupational success and evaluate the hypothesis that appearance based biases are consistent with predictions based on evolutionary theories of coalition formation and leadership choice. We discuss why appearance based effects are so pervasive, addressing ideas about a “kernel of truth” in attributions and about coalitional psychology. We additionally highlight that appearance may be differently related to success at work according to the types of job or task involved. For example, leaders may be chosen because the characteristics they possess are seen as best suited to lead in particular situations. During a time of war, a dominant-appearing leader may inspire confidence and intimidate enemies while during peace-time, when negotiation and diplomacy are needed, interpersonal skills may outweigh the value of a dominant leader. In line with these ideas, masculine-faced leaders are favored in war-time scenarios while feminine-faced leaders are favored in peace-time scenarios. We suggest that such environment or task specific competencies may be prevalent during selection processes, whereby individuals whose appearance best matches perceived task competences are most likely selected, and propose the general term “task-congruent selection” to describe these effects. Overall, our review highlights how potentially adaptive biases could influence choices in the work place. With respect to certain biases

  9. National Needs for Appearance Metrology

    Science.gov (United States)

    Nadal, Maria E.

    2003-04-01

    Appearance greatly influences a customer's judgement of the quality and acceptability of manufactured products, as yearly there is approximately $700 billion worth of shipped goods for which overall appearance is critical to their sale. For example, appearance is reported to be a major factor in about half of automobile purchases. The appearance of an object is the result of a complex interaction of the light field incident upon the object, the scattering and absorption properties of the object, and human perception. The measurable attributes of appearance are divided into color (hue, saturation, and lightness) and geometry (gloss, haze). The nature of the global economy has increased international competition and the need to improve the quality of many manufactured products. Since the manufacturing and marketing of these products is international in scope, the lack of national appearance standard artifacts and measurement protocols results in a direct loss to the supplier. One of the primary missions of the National Institute of Standards and Technology (NIST) is to strengthen the U.S. economy by working with industry to develop and apply technology, measurements and standards. The NIST Physics Laboratory has established an appearance metrology laboratory. This new laboratory provides calibration services for 0^o/45^o color standards and 20^o°, 60^o°, and 85^o° specular gloss, and research in the colorimetric characterization of gonioapparent including a new Standard Reference Material for metallic coatings (SRM 2017) and measurement protocols for pearlescent coatings. These services are NIST's first appearance metrology efforts in many years; a response to needs articulated by industry. These services are designed to meet demands for improved measurements and standards to enhance the acceptability of final products since appearance often plays a major role in their acceptability.

  10. Neutrino oscillations with the OPERA experiment

    CERN Document Server

    Galati, Giuliana

    2016-01-01

    OPERA (Oscillation Project with Emulsion tRacking Apparatus) was a long-baseline experiment at the Gran Sasso laboratory (LNGS) designed to search for ν μ → ν τ oscillations in appearance mode. OPERA took data from 2008 to 2012 with the CNGS neutrino beam from CERN. The observation of five ν τ candidates allowed assessing the discovery of ν μ → ν τ appearance in the CNGS neutrino beam with a significance of 5 . 1 σ . The data analysis is still ongoing, with the goal of improving the sensitivity to the sterile neutrino search in the ν μ → ν τ and ν μ → ν e appearance channels and oscillation parameters with reduced statistical uncertainties. Current results will be presented and perspectives discussed.

  11. Color and appearance metrology facility

    Data.gov (United States)

    Federal Laboratory Consortium — The NIST Physical Measurement Laboratory has established the color and appearance metrology facility to support calibration services for 0°/45° colored samples, 20°,...

  12. Appearance questions can be misleading

    DEFF Research Database (Denmark)

    Hansen, Mikkel; Markman, Ellen M.

    2005-01-01

    Preschoolers' success on the appearance-reality task is a milestone in theory-of-mind development. On the standard task children see a deceptive object, such as a sponge that looks like a rock, and are asked, "What is this really?" and "What does this look like?" Children below 4 1/2 years of age...... fail saying that the object not only is a sponge but also looks like a sponge. We propose that young children's difficulty stems from ambiguity in the meaning of "looks like." This locution can refer to outward appearance ("Peter looks like Paul") but in fact often refers to likely reality ("That looks...... like Jim"). We propose that "looks like" is taken to refer to likely reality unless the reality is already part of the common ground of the conversation. Because this joint knowledge is unclear to young children on the appearance-reality task, they mistakenly think the appearance question is about...

  13. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  14. Object Knowledge Modulates Colour Appearance

    Directory of Open Access Journals (Sweden)

    Christoph Witzel

    2011-01-01

    Full Text Available We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

  15. Object knowledge modulates colour appearance

    Science.gov (United States)

    Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

    2011-01-01

    We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

  16. Adolescent perceptions of cigarette appearance.

    Science.gov (United States)

    Ford, Allison; Moodie, Crawford; MacKintosh, Anne M; Hastings, Gerard

    2014-06-01

    To reduce the possibility of cigarette appearance misleading consumers about harm caused by the product, the European Commission's draft Tobacco Products Directive proposed banning cigarettes implied a more pleasant and palatable smoke for young smokers. A long brown cigarette was viewed as particularly unattractive and communicated a stronger and more harmful product. This exploratory study provides some support that standardising cigarette appearance could reduce the appeal of cigarettes in adolescents and reduce the opportunity for stick design to mislead young smokers in terms of harm. © The Author 2013. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  17. Appearance, discrimination, and reaction qualifications

    OpenAIRE

    Mason, Andrew

    2016-01-01

    When are selectors for advantaged social positions morally justified in giving weight to the appearance of the candidates? In order to address this issue adequately, we need to know when a person’s appearance can be a legitimate qualification for a position. Some of the hardest cases are jobs that involve interacting with clients or customers who prefer to deal with good-looking employees or who respond more favourably to them. But there is also a wide range of difficult cases in which an unc...

  18. A memristor-based third-order oscillator: beyond oscillation

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-10-06

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  19. A memristor-based third-order oscillator: beyond oscillation

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  20. Cascades from nu_E above 1020 eV

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Spencer R.

    2004-12-21

    At very high energies, the Landau-Pomeranchuk-Migdal effect reduces the cross sections for electron bremsstrahlung and photon e{sup +}e{sup -} pair production. The fractional electron energy loss and pair production cross sections drop as the energy increases. In contrast, the cross sections for photonuclear interactions grow with energy. In solids and liquids, at energies above 10{sup 20} eV, photonuclear reactions dominate, and showers that originate as photons or electrons quickly become hadronic showers. These electron-initiated hadronic showers are much shorter (due to the absence of the LPM effect), but wider than purely electromagnetic showers would be. This change in shape alters the spectrum of the electromagnetic and acoustic radiation emitted from the shower. These alterations have important implications for existing and planned searches for radiation from u{sub e} induced showers above 10{sup 20} eV, and some existing limits should be reevaluated.

  1. Color Categories and Color Appearance

    Science.gov (United States)

    Webster, Michael A.; Kay, Paul

    2012-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

  2. CT appearance of juvenile angiofibroma

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Jun; Hara, Kazuo (Sumitomo Hospital, Osaka (Japan)); Fukuzumi, Akio; Uchida, Hideo

    1983-06-01

    Three verified cases of juvenile angiofibroma were presented. All of them were young and adolescent male CT proved to be an ideal tool in evaluating the extension of this tumor. The appearance on plain CT was multilobulated with displacement of the adjacent bony structures. On enhancement, there was intense staining of the tumor.

  3. Optical appearance of white holes

    International Nuclear Information System (INIS)

    Lake, K.; Roeder, R.C.

    1978-01-01

    The detailed optical properties of white holes are examined within the framework of geometrical optics. It is shown that the appearance of the objects most likely to be observed at late times is in fact determined by their early histories. These ccalculations indicate that one cannot invoke the simple concept of a stable white hole as a ''natural'' explanation of highly energetic astrophysical phenomena

  4. Memory colours affect colour appearance.

    Science.gov (United States)

    Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R

    2016-01-01

    Memory colour effects show that colour perception is affected by memory and prior knowledge and hence by cognition. None of Firestone & Scholl's (F&S's) potential pitfalls apply to our work on memory colours. We present a Bayesian model of colour appearance to illustrate that an interaction between perception and memory is plausible from the perspective of vision science.

  5. Oscillations of disks

    CERN Document Server

    Kato, Shoji

    2016-01-01

    This book presents the current state of research on disk oscillation theory, focusing on relativistic disks and tidally deformed disks. Since the launch of the Rossi X-ray Timing Explorer (RXTE) in 1996, many high-frequency quasiperiodic oscillations (HFQPOs) have been observed in X-ray binaries. Subsequently, similar quasi-periodic oscillations have been found in such relativistic objects as microquasars, ultra-luminous X-ray sources, and galactic nuclei. One of the most promising explanations of their origin is based on oscillations in relativistic disks, and a new field called discoseismology is currently developing. After reviewing observational aspects, the book presents the basic characteristics of disk oscillations, especially focusing on those in relativistic disks. Relativistic disks are essentially different from Newtonian disks in terms of several basic characteristics of their disk oscillations, including the radial distributions of epicyclic frequencies. In order to understand the basic processes...

  6. Oscillations in stellar atmospheres

    International Nuclear Information System (INIS)

    Costa, A.; Ringuelet, A.E.; Fontenla, J.M.

    1989-01-01

    Atmospheric excitation and propagation of oscillations are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of oscillations, the minimum frequencies are obtained for radially propagating waves. The comparison of the minimum frequencies obtained for a variety of stellar types is in good agreement with the observed periods of the oscillations. The role of the atmosphere in the globar stellar pulsations is thus emphasized. 7 refs

  7. Principal oscillation patterns

    International Nuclear Information System (INIS)

    Storch, H. von; Buerger, G.; Storch, J.S. von

    1993-01-01

    The Principal Oscillation Pattern (POP) analysis is a technique which is used to simultaneously infer the characteristic patterns and time scales of a vector time series. The POPs may be seen as the normal modes of a linearized system whose system matrix is estimated from data. The concept of POP analysis is reviewed. Examples are used to illustrate the potential of the POP technique. The best defined POPs of tropospheric day-to-day variability coincide with the most unstable modes derived from linearized theory. POPs can be derived even from a space-time subset of data. POPs are successful in identifying two independent modes with similar time scales in the same data set. The POP method can also produce forecasts which may potentially be used as a reference for other forecast models. The conventional POP analysis technique has been generalized in various ways. In the cyclostationary POP analysis, the estimated system matrix is allowed to vary deterministically with an externally forced cycle. In the complex POP analysis not only the state of the system but also its ''momentum'' is modeled. Associated correlation patterns are a useful tool to describe the appearance of a signal previously identified by a POP analysis in other parameters. (orig.)

  8. Imaging appearances of cholesterol pneumonia

    International Nuclear Information System (INIS)

    Miao Yanwei; Zhang Jingwen; Wu Jianlin; Zhou Yong; Li Mingwu; Lei Zhen; Shi Lifu

    2006-01-01

    Objection: To analyze the imaging appearances of cholesterol pneumonia. Methods We retrospectively analyzed the X-ray and CT findings of 3 patients with cholesterol pneumonia confirmed pathologically and reviewed correlative literature. Results: Lesions similar to mass were found in X-ray and CT imaging of three cases. Two of them appeared cavity with fluid-level and one showed multiple ring enhancement after CT contrast. The course of disease was very. long and it had no respond to antibiotic therapy. Amounts of foam cells rich in cholesterol crystal were detected in pathological examination. Conclusions: Cholesterol pneumonia is a rare chronic pulmonary idiopathic disease, and the radiological findings can do some help to its diagnosis. (authors)

  9. Benign chondroblastoma - malignant radiological appearances

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, K.; Treugut, H.; Mueller, G.E.

    1980-04-01

    The very rare benign chondroblastoma occasionally invades soft tissues and may grow beyond the epiphysis into the metaphysis. In the present case such a tumour did not show the typical radiological appearances, but presented malignant features both on plain films and on the angiogram. The importance of biopsy of tumours which cannot be identified with certainty must be stressed before radical surgery is carried out.

  10. Cerebral candidiasis. Computed tomography appearance

    International Nuclear Information System (INIS)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-01-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.)

  11. Cerebral candidiasis. Computed tomography appearance

    Energy Technology Data Exchange (ETDEWEB)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  12. Subcutaneous granuloma annulare: radiologic appearance

    International Nuclear Information System (INIS)

    Kransdorf, M.J.; Murphey, M.D.; Temple, H.T.

    1998-01-01

    Objective. Granuloma annulare is an uncommon benign inflammatory dermatosis characterized by the formation of dermal papules with a tendency to form rings. There are several clinically distinct forms. The subcutaneous form is the most frequently encountered by radiologists, with the lesion presenting as a superficial mass. There are only a few scattered reports of the imaging appearance of this entity in the literature. We report the radiologic appearance of five cases of subcutaneous granuloma annulare. Design and patients. The radiologic images of five patients (three male, two female) with subcutaneous granuloma annulare were retrospectively studied. Mean patient age was 6.4 years (range, 2-13 years). The lesions occurred in the lower leg (two), foot, forearm, and hand. MR images were available for all lesions, gadolinium-enhanced imaging in three cases, radiographs in four, and bone scintigraphy in one. Results. Radiographs showed unmineralized nodular masses localized to the subcutaneous adipose tissue. The size range, in greatest dimension on imaging studies, was 1-4 cm. MR images show a mass with relatively decreased signal intensity on all pulse sequences, with variable but generally relatively well defined margins. There was extensive diffuse enhancement following gadolinium administration. Conclusion. The radiologic appearance of subcutaneous granuloma annulare is characteristic, typically demonstrating a nodular soft-tissue mass involving the subcutaneous adipose tissue. MR images show a mass with relatively decreased signal intensity on all pulse sequences and variable but generally well defined margins. There is extensive diffuse enhancement following gadolinium administration. Radiographs show a soft-tissue mass or soft-tissue swelling without evidence of bone involvement or mineralization. This radiologic appearance in a young individual is highly suggestive of subcutaneous granuloma annulare. (orig.)

  13. The imaging appearance of crayons

    International Nuclear Information System (INIS)

    McAllister, Aaron S.; Jones, Blaise V.; Lall, Neil U.; Tawfik, Kareem O.

    2017-01-01

    A crayon fragment was determined to be the source of a foreign body inflammatory process in the masticator space of a 15-month-old boy. The appearance of the crayon on CT and MR imaging was unexpected, leading to a further analysis of the imaging features of crayons. To investigate and characterize the imaging appearance of crayons at CT and MRI. The authors obtained CT and MR images of 22 crayons from three manufacturers and three non-pigmented crayons cast by the authors. CT attenuation of the crayons and diameter of the MRI susceptibility signal dropout were plotted versus brand and color. All crayons demonstrated a longitudinal central hypo-attenuating tract. Crayon attenuation varied by brand and color. All of the crayons demonstrated a signal void on T1 and T2 imaging and signal dropout on susceptibility-weighted imaging, the diameter of which varied by brand and color. Understanding the imaging appearance of crayons could help in the correct identification of a crayon as a foreign body on imaging studies, even when it is located in unusual places. (orig.)

  14. Color categories and color appearance

    Science.gov (United States)

    Webster, Michael A.; Kay, Paul

    2011-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

  15. MR appearance of central neurocytoma

    International Nuclear Information System (INIS)

    Chang, K.H.; Han, M.H.; Kim, D.G.; Chi, J.G.; Suh, D.C.; Kim, S.J.; Cha, S.H.; Han, M.C.

    1993-01-01

    To provide a detailed description of the MR appearances of central neurocytoma, MR images of 13 patients with central neurocytoma were retrospectively reviewed and compared with CT examinations. The histology was confirmed by ultrastructural and immunohistochemical studies. In 12 patients the tumors were histologically benign and located in the anterior part of the lateral ventricle, 6 of which extended to the 3rd ventricle. There was one case of a histologically malignant variant involving the thalamus and lateral ventricle. The tumors were primarily solid, but contained cysts (85%, 11/13), calcifications (69%, 9/13), and signal void from tumor vessels (62%, 8/13), frequently producing heterogeneous signal intensity on both T1- and T2-weighted images. Most of the solid portion appeared isointense or slightly hyperintense relative to the cerebral cortex on all MR pulse sequences. Calcifications were iso- or hypointense on MR, making them difficult to characterize with MR alone. Intratumoral hemorrhage was seen in 2 patients on MR but not on CT. Contrast enhancement was variable in degree and pattern. Coronal and sagittal MR images were valuable in evaluating the tumor extent and origin site, and in planning the surgical approach. It is concluded that MR imaging appears to be more useful than CT in the overall evaluation of central neurocytoma, even though calcification is better characterized with CT. (orig.)

  16. The imaging appearance of crayons

    Energy Technology Data Exchange (ETDEWEB)

    McAllister, Aaron S.; Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Lall, Neil U. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Ochsner Health System, Department of Radiology, New Orleans, LA (United States); Tawfik, Kareem O. [University of Cincinnati College of Medicine, Department of Otolaryngology-Head and Neck Surgery, Cincinnati, OH (United States)

    2017-05-15

    A crayon fragment was determined to be the source of a foreign body inflammatory process in the masticator space of a 15-month-old boy. The appearance of the crayon on CT and MR imaging was unexpected, leading to a further analysis of the imaging features of crayons. To investigate and characterize the imaging appearance of crayons at CT and MRI. The authors obtained CT and MR images of 22 crayons from three manufacturers and three non-pigmented crayons cast by the authors. CT attenuation of the crayons and diameter of the MRI susceptibility signal dropout were plotted versus brand and color. All crayons demonstrated a longitudinal central hypo-attenuating tract. Crayon attenuation varied by brand and color. All of the crayons demonstrated a signal void on T1 and T2 imaging and signal dropout on susceptibility-weighted imaging, the diameter of which varied by brand and color. Understanding the imaging appearance of crayons could help in the correct identification of a crayon as a foreign body on imaging studies, even when it is located in unusual places. (orig.)

  17. Pair creation and plasma oscillations

    International Nuclear Information System (INIS)

    Prozorkevich, A. V.; Vinnik, D. V.; Schmidt, S. M.; Hecht, M. B.; Roberts, C. D.

    2000-01-01

    We describe aspects of particle creation in strong fields using a quantum kinetic equation with a relaxation-time approximation to the collision term. The strong electric background field is determined by solving Maxwell's equation in tandem with the Vlasov equation. Plasma oscillations appear as a result of feedback between the background field and the field generated by the particles produced. The plasma frequency depends on the strength of the initial background fields and the collision frequency, and is sensitive to the necessary momentum-dependence of dressed-parton masses

  18. q-deformed oscillators and D-branes on conifold

    International Nuclear Information System (INIS)

    Okuyama, Kazumi

    2009-01-01

    We study the q-deformed oscillator algebra acting on the wavefunctions of non-compact D-branes in the topological string on conifold. We find that the mirror B-model curve of conifold appears from the commutation relation of the q-deformed oscillators

  19. The Oscillator Principle of Nature

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2012-01-01

    Oscillators are found on all levels in Nature. The general oscillator concept is defined and investigated. Oscillators may synchronize into fractal patterns. Apparently oscillators are the basic principle in Nature. The concepts of zero and infinite are discussed. Electronic manmade oscillators...

  20. Scintigraphic appearances of Gaucher's disease

    International Nuclear Information System (INIS)

    Okada, Junichi; Uchiyama, Guio; Hayakawa, Kazushige; Araki, Tsutomu; Hayashi, Sanshin; Yamada, Kayoko; Seto, Kazuhiko

    1985-01-01

    Gaucher's disease is an inborn error of metabolism in which glucocerebroside accumlates within reticuloendotherial cells of spleen, liver and bone marrow. The scintigraphic appearances are described in a 19-year-old man with Gaucher's disease. The colloid scan showed increased uptake in the lung and bone marrow of legs where the reticuloendotherial system was activated. The bone scan demonstrated increased activity in the metaphyseal and diaphyseal region infiltrated by Gaucher's cell. Ga-67 was thought to be accumlated in the progressive focus of the disease. (author)

  1. Normal pediatric postmortem CT appearances

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Willemijn M.; Bosboom, Dennis G.H.; Koopmanschap, Desiree H.J.L.M. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Nievelstein, Rutger A.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Nikkels, Peter G.J. [University Medical Center Utrecht, Department of Pathology, Utrecht (Netherlands); Rijn, Rick R. van [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands)

    2015-04-01

    Postmortem radiology is a rapidly developing specialty that is increasingly used as an adjunct to or substitute for conventional autopsy. The goal is to find patterns of disease and possibly the cause of death. Postmortem CT images bring to light processes of decomposition most radiologists are unfamiliar with. These postmortem changes, such as the formation of gas and edema, should not be mistaken for pathological processes that occur in living persons. In this review we discuss the normal postmortem thoraco-abdominal changes and how these appear on CT images, as well as how to differentiate these findings from those of pathological processes. (orig.)

  2. CT appearances of abdominal tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.-K., E-mail: leewk33@hotmail.com [Department of Medical Imaging, St Vincent' s Hospital, University of Melbourne, Fitzroy, Victoria (Australia); Van Tonder, F.; Tartaglia, C.J.; Dagia, C. [Department of Medical Imaging, St Vincent' s Hospital, University of Melbourne, Fitzroy, Victoria (Australia); Cazzato, R.L. [Department of Radiology, Universita Campus Bio-Medico di Roma, Rome (Italy); Duddalwar, V.A. [Department of Radiology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California (United States); Chang, S.D. [Department of Medical Imaging, Vancouver General Hospital, University of British Columbia, British Columbia (Canada)

    2012-06-15

    The purpose of this article is to review and illustrate the spectrum of computed tomography (CT) appearances of abdominal tuberculosis. Tuberculosis can affect any organ or tissue in the abdomen, and can be mistaken for other inflammatory or neoplastic conditions. The most common sites of tuberculosis in the abdomen include lymph nodes, genitourinary tract, peritoneal cavity and gastrointestinal tract. The liver, spleen, biliary tract, pancreas and adrenals are rarely affected, but are more likely in HIV-seropositive patients and in miliary tuberculosis. This article should alert the radiologist to consider abdominal tuberculosis in the correct clinical setting to ensure timely diagnosis and enable appropriate treatment.

  3. CT appearances of abdominal tuberculosis

    International Nuclear Information System (INIS)

    Lee, W.-K.; Van Tonder, F.; Tartaglia, C.J.; Dagia, C.; Cazzato, R.L.; Duddalwar, V.A.; Chang, S.D.

    2012-01-01

    The purpose of this article is to review and illustrate the spectrum of computed tomography (CT) appearances of abdominal tuberculosis. Tuberculosis can affect any organ or tissue in the abdomen, and can be mistaken for other inflammatory or neoplastic conditions. The most common sites of tuberculosis in the abdomen include lymph nodes, genitourinary tract, peritoneal cavity and gastrointestinal tract. The liver, spleen, biliary tract, pancreas and adrenals are rarely affected, but are more likely in HIV-seropositive patients and in miliary tuberculosis. This article should alert the radiologist to consider abdominal tuberculosis in the correct clinical setting to ensure timely diagnosis and enable appropriate treatment.

  4. CT appearance of pulmonary ligament

    Energy Technology Data Exchange (ETDEWEB)

    Im, Jung Gi; Han, Man Chung; Chin, Soo Yil [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1984-03-15

    Pulmonary ligament consists of 2 serosal of pleura that connect the lower to the mediastinum. Author analyse and present CT appearance of pulmonary ligament of the 40 normal and abnormal patients on the basis of anatomic knowledge from the cross section of cadaver. Left pulmonary ligament is more frequency visualized than the right. The most important CT landmark in localizing pulmonary ligament is the esophagus where the ligament attaches on its lateral wall. Pitfalls in CT identification of pulmonary ligament are right phrenic nerve and right pericardiacophrenic vessels which emerge from lateral wall of the IVC and wall of the emphysematous bulla in the region of the pulmonary ligament.

  5. CT appearance of pulmonary ligament

    International Nuclear Information System (INIS)

    Im, Jung Gi; Han, Man Chung; Chin, Soo Yil

    1984-01-01

    Pulmonary ligament consists of 2 serosal of pleura that connect the lower to the mediastinum. Author analyse and present CT appearance of pulmonary ligament of the 40 normal and abnormal patients on the basis of anatomic knowledge from the cross section of cadaver. Left pulmonary ligament is more frequency visualized than the right. The most important CT landmark in localizing pulmonary ligament is the esophagus where the ligament attaches on its lateral wall. Pitfalls in CT identification of pulmonary ligament are right phrenic nerve and right pericardiacophrenic vessels which emerge from lateral wall of the IVC and wall of the emphysematous bulla in the region of the pulmonary ligament

  6. On the Dirac oscillator

    International Nuclear Information System (INIS)

    Rodrigues, R. de Lima

    2007-01-01

    In the present work we obtain a new representation for the Dirac oscillator based on the Clifford algebra C 7. The symmetry breaking and the energy eigenvalues for our model of the Dirac oscillator are studied in the non-relativistic limit. (author)

  7. A Conspiracy of Oscillators

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2008-01-01

    We discuss nonlinear mechanical systems containing several oscillators whose frequecies are all much higher than frequencies associated with the remaining degrees of freedom. In this situation a near constant of the motion, an adiabatic invariant, exists which is the sum of all the oscillator...... actions. The phenomenon is illustrated, and calculations of the small change of the adiabatic invariant is outlined....

  8. Synchronization of hyperchaotic oscillators

    DEFF Research Database (Denmark)

    Tamasevicius, A.; Cenys, A.; Mykolaitis, G.

    1997-01-01

    Synchronization of chaotic oscillators is believed to have promising applications in secure communications. Hyperchaotic systems with multiple positive Lyapunov exponents (LEs) have an advantage over common chaotic systems with only one positive LE. Three different types of hyperchaotic electronic...... oscillators are investigated demonstrating synchronization by means of only one properly selected variable....

  9. Optical appearance of distant galaxies

    International Nuclear Information System (INIS)

    Pritchet, C.; Kline, M.I.

    1981-01-01

    We have used the recent evolutionary and K-corrections of Bruzual and Kron to predict the optical appearance of galaxies spanning a wide range of magnitudes and redshifts. It is found that nearly all galaxies with J< or approx. =25 are resolved in 1-arcsec seeing. At fixed apparent magnitude, galaxies with large redshifts are more diffuse in appearance than those at small z. This fact causes the most distant galaxies at any magnitude level to be missed, and, depending on the measurement algorithm employed, may cause the luminosities of detected galaxies to be seriously underestimated. Both of these effects deserve consideration when attempting to interpret number counts of faint galaxies. Observations made with the Space Telescope are expected to resolve nearly all galaxies at J< or approx. =27.5; however, several factors conspire to render Space Telescope observations less effective than certain ground-based CCD observations for the optical detection of distant galaxies. Finally, we note that most of our conclusions are unaffected by changes in the assumed cosmology

  10. NOvA Short-Baseline Tau Neutrino Appearance Search

    Energy Technology Data Exchange (ETDEWEB)

    Keloth, Rijeesh [Cochin U.; Aurisano, Adam [Cincinnati U.; Sousa, Alexander [Cincinnati U.; Davies, Gavin S [Indiana U.; Suter, Louise [Fermilab; Plunkett, Robert K [Fermilab

    2017-10-01

    Standard three-flavor neutrino oscillations have well explained by a wide range of neutrino experiments. However, the anomalous results, such as electron-antineutrino excess seen by LSND and MiniBooNE do not fit the three-flavor paradigm. This can be explained by an additional fourth flavor sterile neutrino at a larger scale than the existing three flavor neutrinos. The NOvA experiment consists of two finely segmented, liquid scintillator detectors operating 14 .6 mrad off-axis from the NuMI muon-neutrino beam. The Near Detector is located on the Fermilab campus, 1 km from the NuMI target, while the Far Detector is located at Ash River, MN, 810 km from the NuMI target. The NOvA experiment is primarily designed to measure electron-neutrino appearance at the Far Detector using the Near Detector to control systematic uncertainties; however, the Near Detector is well suited for searching for anomalous short-baseline oscillations. This poster will present a novel method for selecting tau neutrino interactions with high purity at the Near Detector using a convolutional neural network. Using this method, the sensitivity to anomalous short-baseline tau-neutrino appearance due to sterile neutrino oscillations will be presented.

  11. Oscillations and chaos in renal blood flow control

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H

    1993-01-01

    In normotensive, halothane-anesthetized rats, oscillations can be found both in the single-nephron blood flow and in the tubular pressure. Experimental data and computer simulations support the hypothesis that the oscillations are caused by the tubuloglomerular feedback (TGF) mechanism. Model...... oscillations. The parameter range where model studies show instability overlaps with the physiologic range for the values of the same parameters. The system appears to be poised on the border between stability and oscillation, and a small parameter change may cause the system to move from one state...

  12. MRI appearance of muscle denervation

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, S. [University Hospital of Wales, Department of Radiology, Cardiff (United Kingdom); Venkatanarasimha, N.; Walsh, M.A.; Hughes, P.M. [Derriford Hospital, Department of Radiology, Plymouth (United Kingdom)

    2008-05-15

    Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation. (orig.)

  13. Ultrasound appearance of knuckle pads

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ben, R. [Univ. of Alabama, Birmingham (United States). Dept. of Diagnostic Radiology; Dehghanpisheh, K.; Chatham, W.W.; Alarcon, G.S. [Univ. of Alabama, Birmingham (United States). Dept. of Medicine; Lee, D.H.; Oakes, J. [Univ. of Alabama, Birmingham (United States). Dept. of Surgery

    2006-11-15

    We describe the ultrasound appearance of knuckle pads. Retrospective analysis of imaging in a series of five patients initially referred for evaluation of periarticular soft-tissue swelling of the hands involving the dorsum of the PIP and MP joints. Two patients had associated Dupuytren's contractures. Ultrasound and radiographs of the hands in all patients were reviewed and correlated with clinical history and physical exams. Radiographs in four patients demonstrated dorsal soft-tissue thickening. Ultrasound exams showed increased dorsal subcutaneous thickening, with either diffuse or focal hypoechoic areas corresponding to the areas of soft-tissue fullness identified on physical exam. No erosions or synovial proliferation were identified either by radiographs or ultrasound of the underlying joints. Knuckle pads can sometimes be difficult to distinguish from synovitis on physical examination. Musculoskeletal ultrasound can quickly identify these superficial lesions and exclude underlying synovial proliferation.

  14. Interplay between Appearance and Disappearance Channels for Precision Measurements of θ₂₃ and δ

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar; Minakata, Hisakazu; Parke, Stephen J.

    2014-11-01

    We discuss how the CP violating phase δ and the mixing angle θ₂₃ can be measured precisely in an environment where there are strong correlations between them. This is achieved by paying special attention to the mutual roles and the interplay between the appearance and the disappearance channels in long-baseline neutrino oscillation experiments. We analyze and clarify the general structure of the θ₂₃ - θ₁₃ - δ degeneracy for both the appearance and disappearance channels in a more complete fashion than what has previously been discussed in the literature. A full understanding of this degeneracy is of vital importance if θ₂₃ is close to maximal mixing. The relative importance between the appearance and disappearance channels depends upon the particular setup and how close to maximal mixing Nature has chosen the value for θ₂₃. For facilities that operate with a narrow band beam or a wide band beam centered on the first oscillation extremum, the contribution of the disappearance channel depends critically on the systematic uncertainties assumed for this channel. Whereas for facilities that operate at energies above the first oscillation extremum or at the second oscillation extremum the appearance channels dominate. On the other hand, for δ we find that the disappearance channel usually improves the sensitivity, modestly for facilities around the first oscillation extremum and more significantly for facilities operating at an energy above the first oscillation extremum, especially near δ ~ ± π/2.

  15. Facial appearance affects science communication.

    Science.gov (United States)

    Gheorghiu, Ana I; Callan, Mitchell J; Skylark, William J

    2017-06-06

    First impressions based on facial appearance predict many important social outcomes. We investigated whether such impressions also influence the communication of scientific findings to lay audiences, a process that shapes public beliefs, opinion, and policy. First, we investigated the traits that engender interest in a scientist's work, and those that create the impression of a "good scientist" who does high-quality research. Apparent competence and morality were positively related to both interest and quality judgments, whereas attractiveness boosted interest but decreased perceived quality. Next, we had members of the public choose real science news stories to read or watch and found that people were more likely to choose items that were paired with "interesting-looking" scientists, especially when selecting video-based communications. Finally, we had people read real science news items and found that the research was judged to be of higher quality when paired with researchers who look like "good scientists." Our findings offer insights into the social psychology of science, and indicate a source of bias in the dissemination of scientific findings to broader society.

  16. LSND neutrino oscillation results

    International Nuclear Information System (INIS)

    Louis, W.C.

    1996-01-01

    In the past several years, a number of experiments have searched for neutrino oscillations, where a neutrino of one type (say bar ν μ ) spontaneously transforms into a neutrino of another type (say bar ν 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 ν μ oscillations. Additional data are reported here which provide stronger evidence for neutrino oscillations

  17. Neutrino Oscillation Physics

    International Nuclear Information System (INIS)

    Kayser, Boris

    2014-01-01

    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

  18. Neutrino Oscillation Physics

    Energy Technology Data Exchange (ETDEWEB)

    Kayser, Boris [Fermilab (United States)

    2014-07-01

    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.

  19. Oscillator, neutron modulator

    International Nuclear Information System (INIS)

    Agaisse, R.; Leguen, R.; Ombredane, D.

    1960-01-01

    The authors present a mechanical device and an electronic control circuit which have been designed to sinusoidally modulate the reactivity of the Proserpine atomic pile. The mechanical device comprises an oscillator and a mechanism assembly. The oscillator is made of cadmium blades which generate the reactivity oscillation. The mechanism assembly comprises a pulse generator for cycle splitting, a gearbox and an engine. The electronic device comprises or performs pulse detection, an on-off device, cycle pulse shaping, phase separation, a dephasing amplifier, electronic switches, counting scales, and control devices. All these elements are briefly presented

  20. Search for νμ → νe oscillations

    International Nuclear Information System (INIS)

    Godley, A.R.

    1998-01-01

    Full text: Neutrino oscillations, the changing of neutrino flavour state from one of τ, μ or e, to another, are proof of massive neutrinos, in turn pointing to Physics beyond the Standard Model, and so are of great current interest. Solar and atmospheric neutrino results suggested evidence for neutrino oscillations. Further, a tau neutrino mass of ∼ 10 eV could supply the missing mass needed to close the Universe. To satisfy the increasing interest, CERN's Neutrino Physics Program commissioned two concurrent experiments to investigate the possibility of neutrino oscillations, one of which is NOMAD, Neutrino Oscillation Magnetic Detector. NOMAD was designed to verify or deny the earlier positive neutrino oscillations results by searching for muon to tauon neutrino oscillations in accelerator neutrinos. The LSND experiment later provided evidence for muon to electron neutrino oscillations, but due to the multi-purpose design of NOMAD, it was also possible to investigate this channel. Moreover, the area of phase space being uncovered, (related to neutrino energy and oscillation length), overlaps considerably with that of LSND. An electron neutrino oscillation search involves looking for electron neutrinos in what is primarily a muon neutrino beam, with just a small contamination of electron neutrinos. It is surmised that the excess of electron neutrinos come from oscillated muon neutrinos. This type of search is called an appearance search. The principles of such a search will be detailed herein. These include a breakdown of the CERN Neutrino Beam and a method for detecting and collating different neutrino flavours at NOMAD

  1. OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Gritschneder, Matthias; Heigl, Stefan; Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de [University Observatory Munich, LMU Munich, Scheinerstrasse 1, D-81679 Munich (Germany)

    2017-01-10

    We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid-based AMR code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, such as with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation, and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process “geometrical fragmentation.” In our realization, the spacing between the cores matches the wavelength of the sinusoidal perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristic scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. We show that the overall oscillation pattern can hide the infall signature of cores.

  2. Again on neutrino oscillations

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Pontecorvo, B.

    1976-01-01

    The general case is treated of a weak interaction theory in which a term violating lepton charges is present. In such a scheme the particles with definite masses are Majorana neutrinos (2N if in the weak interaction participate N four-component neutrinos). Neutrino oscillations are discussed and it is shown that the minimum average intensity at the earth of solar neutrinos is 1/2N of the intensity expected when oscillations are absent

  3. Oscillators and operational amplifiers

    OpenAIRE

    Lindberg, Erik

    2005-01-01

    A generalized approach to the design of oscillators using operational amplifiers as active elements is presented. A piecewise-linear model of the amplifier is used so that it make sense to investigate the eigenvalues of the Jacobian of the differential equations. The characteristic equation of the general circuit is derived. The dynamic nonlinear transfer characteristic of the amplifier is investigated. Examples of negative resistance oscillators are discussed.

  4. Chaotic solar oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blacher, S; Perdang, J [Institut d' Astrophysique, B-4200 Cointe-Ougree (Belgium)

    1981-09-01

    A numerical experiment on Hamiltonian oscillations demonstrates the existence of chaotic motions which satisfy the property of phase coherence. It is observed that the low-frequency end of the power spectrum of such motions is remarkably similar in structure to the low-frequency SCLERA spectra. Since the smallness of the observed solar amplitudes is not a sufficient mathematical ground for inefficiency of non-linear effects the possibility of chaos among solar oscillations cannot be discarded a priori.

  5. Case for neutrino oscillations

    International Nuclear Information System (INIS)

    Ramond, P.

    1982-01-01

    The building of a machine capable of producing an intense, well-calibrated beam of muon neutrinos is regarded by particle physicists with keen interest because of its ability of studying neutrino oscillations. The possibility of neutrino oscillations has long been recognized, but it was not made necessary on theoretical or experimental grounds; one knew that oscillations could be avoided if neutrinos were massless, and this was easily done by the conservation of lepton number. The idea of grand unification has led physicists to question the existence (at higher energies) of global conservation laws. The prime examples are baryon-number conservation, which prevents proton decay, and lepton-number conservation, which keeps neutrinos massless, and therefore free of oscillations. The detection of proton decay and neutrino oscillations would therefore be an indirect indication of the idea of Grand Unification, and therefore of paramount importance. Neutrino oscillations occur when neutrinos acquire mass in such a way that the neutrino mass eigenstates do not match the (neutrino) eigenstates produced by the weak interactions. We shall study the ways in which neutrinos can get mass, first at the level of the standard SU 2 x U 1 model, then at the level of its Grand Unification Generalizations

  6. Power oscillations in BWR reactors

    International Nuclear Information System (INIS)

    Espinosa P, G.

    2002-01-01

    One of the main problems in the operation of BWR type reactors is the instability in power that these could present. One type of oscillations and that is the objective of this work is the named density wave, which is attributed to the thermohydraulic processes that take place in the reactor core. From the beginnings of the development of BWR reactors, the stability of these has been an important aspect in their design, due to its possible consequences on the fuel integrity. The reactor core operates in two phase flow conditions and it is observed that under certain power and flow conditions, power instabilities appear. Studying this type of phenomena is complex, due to that a reactor core is constituted approximately by 27,000 fuel bars with different distributions of power and flow. The phenomena that cause the instability in BWR reactors continue being matter of scientific study. In the literature mainly in nuclear subject, it can be observed that exist different methods and approximations for studying this type of phenomena, nevertheless, their results are focused to establish safety limits in the reactor operation, instead of studying in depth of the knowledge about. Also in this line sense of the reactor data analysis, the oscillations characteristic frequencies are obtained for trying to establish if the power is growing or decreasing. In addition to that before mentioned in this paper it is presented a rigorous study applying the volumetric average method, for obtaining the vacuum waves propagation velocities and its possible connection with the power oscillations. (Author)

  7. Modeling of termokinetic oscillations at partial oxidation of methane

    Science.gov (United States)

    Arutyunov, A. V.; Belyaev, A. A.; Inovenkov, I. N.; Nefedov, V. V.

    2017-12-01

    Partial oxidation of natural gas at moderate temperatures below 1500 K has significant interest for a number of industrial applications. But such processes can proceed at different unstable regimes including oscillating modes. Nonlinear phenomena at partial oxidation of methane were observed at different conditions. The investigation of the complex nonlinear system of equations that describes this process is a real method to insure its stability at industrial conditions and, at the same time, is an effective tool for its further enhancement. Numerical analysis of methane oxidation kinetics in the continuous stirred-tank reactor, with the use of detailed kinetic model has shown the possibility of the appearance of oscillating modes in the appropriate range of reaction parameters that characterize the composition, pressure, reagents flow, thermophysical features of the system, and geometry of the reactor. The appearance of oscillating modes is connected both with the reaction kinetics, heat release and sink and reagents introduction and removing. At that, oscillations appear only at a limited range of parameters, but can be accompanied by significant change in the yield of products. We have determined the range of initial temperature and pressure at which oscillations can be observed, if all other parameters remained fixed. The boundaries of existence of oscillations on the phase plane were calculated. It was shown that depending on the position inside the oscillation region the oscillations have different frequency and amplitude. It was reviled the role of heat exchange with the environment: at the absence of heat exchange the oscillating modes are impossible. In the vicinity of the boundary of phase range, where oscillations exist, significant change of concentration of some products were observed, for example, that of CO2, which in this case one of the principal products is. At that, insignificant increase in pressure not only change the character of CO2 behaving

  8. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  9. Chaotic synchronization of two complex nonlinear oscillators

    International Nuclear Information System (INIS)

    Mahmoud, Gamal M.; Mahmoud, Emad E.; Farghaly, Ahmed A.; Aly, Shaban A.

    2009-01-01

    Synchronization is an important phenomenon commonly observed in nature. It is also often artificially induced because it is desirable for a variety of applications in physics, applied sciences and engineering. In a recent paper [Mahmoud GM, Mohamed AA, Aly SA. Strange attractors and chaos control in periodically forced complex Duffing's oscillators. Physica A 2001;292:193-206], a system of periodically forced complex Duffing's oscillators was introduced and shown to display chaotic behavior and possess strange attractors. Such complex oscillators appear in many problems of physics and engineering, as, for example, nonlinear optics, deep-water wave theory, plasma physics and bimolecular dynamics. Their connection to solutions of the nonlinear Schroedinger equation has also been pointed out. In this paper, we study the remarkable phenomenon of chaotic synchronization on these oscillator systems, using active control and global synchronization techniques. We derive analytical expressions for control functions and show that the dynamics of error evolution is globally stable, by constructing appropriate Lyapunov functions. This means that, for a relatively large set initial conditions, the differences between the drive and response systems vanish exponentially and synchronization is achieved. Numerical results are obtained to test the validity of the analytical expressions and illustrate the efficiency of these techniques for inducing chaos synchronization in our nonlinear oscillators.

  10. Electron Neutrino Appearance in the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Holin, Anna Maria [Univ. College London, Bloomsbury (United Kingdom)

    2010-02-01

    The MINOS experiment is a long-baseline neutrino oscillation experiment which sends a high intensity muon neutrino beam through two functionally identical detectors, a Near detector at the Fermi National Accelerator Laboratory in Illinois, 1km from the beam source, and a Far detector, 734km away, in the Soudan Mine in Minnesota. MINOS may be able to measure the neutrino mixing angle parameter sin213 for the rst time. Detector granularity, however, makes it very hard to distinguish any e appearance signal events characteristic of a non-zero value of θ 13 from background neutral current (NC) and short-track vμ charged current (CC) events. Also, uncertainties in the hadronic shower modeling in the kinematic region characteristic of this analysis are relatively large. A new data-driven background decomposition method designed to address those issues is developed and its results presented. By removing the long muon tracks from vμ-CC events, the Muon Removed Charge Current (MRCC) method creates independent pseudo-NC samples that can be used to correct the MINOS Monte Carlo to agree with the high-statistics Near detector data and to decompose the latter into components so as to predict the expected Far detector background. The MRCC method also provides an important cross-check in the Far detector to test the background in the signal selected region. MINOS finds a 1.0-1.5 σ ve-CC excess above background in the Far detector data, depending on method used, for a total exposure of 3.14 x 1020 protons-on-target. Interpreting this excess as signal, MINOS can set limits on sin213. Using the MRCC method, MINOS sets a limit of sin2 2 θ 13 < 0.265 at the 90% confidence limit for a CP-violating phase δ = 0.

  11. Do muons oscillate?

    International Nuclear Information System (INIS)

    Dolgov, A.D.; Morozov, A.Yu.; Okun, L.B.; Schepkin, M.G.

    1997-01-01

    We develop a theory of the EPR-like effects due to neutrino oscillations in the π→μν decays. Its experimental implications are space-time correlations of the neutrino and muon when they are both detected, while the pion decay point is not fixed. However, the more radical possibility of μ-oscillations in experiments where only muons are detected (as suggested in hep-ph/9509261), is ruled out. We start by discussing decays of monochromatic pions, and point out a few ''paradoxes''. Then we consider pion wave packets, solve the ''paradoxes'', and show that the formulas for μν correlations can be transformed into the usual expressions, describing neutrino oscillations, as soon as the pion decay point is fixed. (orig.)

  12. Oscillations in neutron stars

    International Nuclear Information System (INIS)

    Hoeye, Gudrun Kristine

    1999-01-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l → 4) f-modes we were also able to derive a formula that determines II l+1 from II l and II l-1 to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n c , while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  13. Oscillations in neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Hoeye, Gudrun Kristine

    1999-07-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  14. Oscillating Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-03-07

    In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

  15. Brownian parametric oscillators

    Science.gov (United States)

    Zerbe, Christine; Jung, Peter; Hänggi, Peter

    1994-05-01

    We discuss the stochastic dynamics of dissipative, white-noise-driven Floquet oscillators, characterized by a time-periodic stiffness. Thus far, little attention has been paid to these exactly solvable nonstationary systems, although they carry a rich potential for several experimental applications. Here, we calculate and discuss the mean values and variances, as well as the correlation functions and the Floquet spectrum. As one main result, we find for certain parameter values that the fluctuations of the position coordinate are suppressed as compared to the equilibrium value of a harmonic oscillator (parametric squeezing).

  16. Friedel oscillations in graphene

    DEFF Research Database (Denmark)

    Lawlor, J. A.; Power, S. R.; Ferreira, M.S.

    2013-01-01

    Symmetry breaking perturbations in an electronically conducting medium are known to produce Friedel oscillations in various physical quantities of an otherwise pristine material. Here we show in a mathematically transparent fashion that Friedel oscillations in graphene have a strong sublattice...... asymmetry. As a result, the presence of impurities and/or defects may impact the distinct graphene sublattices very differently. Furthermore, such an asymmetry can be used to explain the recent observations that nitrogen atoms and dimers are not randomly distributed in graphene but prefer to occupy one...

  17. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

  18. Oscillating Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-01-01

    In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

  19. Oscillators from nonlinear realizations

    Science.gov (United States)

    Kozyrev, N.; Krivonos, S.

    2018-02-01

    We construct the systems of the harmonic and Pais-Uhlenbeck oscillators, which are invariant with respect to arbitrary noncompact Lie algebras. The equations of motion of these systems can be obtained with the help of the formalism of nonlinear realizations. We prove that it is always possible to choose time and the fields within this formalism in such a way that the equations of motion become linear and, therefore, reduce to ones of ordinary harmonic and Pais-Uhlenbeck oscillators. The first-order actions, that produce these equations, can also be provided. As particular examples of this construction, we discuss the so(2, 3) and G 2(2) algebras.

  20. First Neutrino Oscillation Results from the NOvA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sachdev, Kanika [Fermilab

    2016-11-29

    NOvA is a long-baseline neutrino oscillation experiment on the NuMI muon neutrino beam at Fermilab. It consists of two functionally identical, nearly fully-active liquid-scintillator tracking calorimeters. The Near Detector (ND) at Fermilab is used to study the neutrino beam spectrum and composition before oscillations occur. The Far Detector in northern Minnesota, 810 km away, observes the oscillated beam and is used to extract the oscillation parameters. NOvA is designed to observe oscillations in two channels: disappearance channel ( ν μ → ν μ ) and ν e appearance channel ( ν μ → ν e ). This paper reports the measurements of both these channels based on the first NOvA data taken from February 16, 2014 till May 15, 2015

  1. Forced oscillations of cracked beam under the stochastic cyclic loading

    Science.gov (United States)

    Matsko, I.; Javors'kyj, I.; Yuzefovych, R.; Zakrzewski, Z.

    2018-05-01

    An analysis of forced oscillations of cracked beam using statistical methods for periodically correlated random processes is presented. The oscillation realizations are obtained on the basis of numerical solutions of differential equations of the second order, for the case when applied force is described by a sum of harmonic and stationary random process. It is established that due to crack appearance forced oscillations acquire properties of second-order periodical non-stationarity. It is shown that in a super-resonance regime covariance and spectral characteristics, which describe non-stationary structure of forced oscillations, are more sensitive to crack growth than the characteristics of the oscillation's deterministic part. Using diagnostic indicators formed on their basis allows the detection of small cracks.

  2. Fourier analysis of the parametric resonance in neutrino oscillations

    International Nuclear Information System (INIS)

    Koike, Masafumi; Ota, Toshihiko; Saito, Masako; Sato, Joe

    2009-01-01

    Parametric enhancement of the appearance probability of the neutrino oscillation under the inhomogeneous matter is studied. Fourier expansion of the matter density profile leads to a simple resonance condition and manifests that each Fourier mode modifies the energy spectrum of oscillation probability at around the corresponding energy; below the MSW resonance energy, a large-scale variation modifies the spectrum in high energies while a small-scale one does in low energies. In contrast to the simple parametric resonance, the enhancement of the oscillation probability is itself an slow oscillation as demonstrated by a numerical analysis with a single Fourier mode of the matter density. We derive an analytic solution to the evolution equation on the resonance energy, including the expression of frequency of the slow oscillation.

  3. Oscillation Baselining and Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    2017-03-27

    PNNL developed a new tool for oscillation analysis and baselining. This tool has been developed under a new DOE Grid Modernization Laboratory Consortium (GMLC) Project (GM0072 - “Suite of open-source applications and models for advanced synchrophasor analysis”) and it is based on the open platform for PMU analysis. The Oscillation Baselining and Analysis Tool (OBAT) performs the oscillation analysis and identifies modes of oscillations (frequency, damping, energy, and shape). The tool also does oscillation event baselining (fining correlation between oscillations characteristics and system operating conditions).

  4. Neutrino oscillation experiments

    International Nuclear Information System (INIS)

    Camilleri, L.

    1996-01-01

    Neutrino oscillation experiments (ν μ →ν e and ν μ →ν τ ) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs

  5. A simple violin oscillator

    Science.gov (United States)

    Jones, R. T.

    1976-01-01

    For acoustic tests the violin is driven laterally at the bridge by a small speaker of the type commonly found in pocket transistor radios. An audio oscillator excites the tone which is picked up by a sound level meter. Gross patterns of vibration modes are obtained by the Chladni method.

  6. Nonlinearity in oscillating bridges

    Directory of Open Access Journals (Sweden)

    Filippo Gazzola

    2013-09-01

    Full Text Available We first recall several historical oscillating bridges that, in some cases, led to collapses. Some of them are quite recent and show that, nowadays, oscillations in suspension bridges are not yet well understood. Next, we survey some attempts to model bridges with differential equations. Although these equations arise from quite different scientific communities, they display some common features. One of them, which we believe to be incorrect, is the acceptance of the linear Hooke law in elasticity. This law should be used only in presence of small deviations from equilibrium, a situation which does not occur in widely oscillating bridges. Then we discuss a couple of recent models whose solutions exhibit self-excited oscillations, the phenomenon visible in real bridges. This suggests a different point of view in modeling equations and gives a strong hint how to modify the existing models in order to obtain a reliable theory. The purpose of this paper is precisely to highlight the necessity of revisiting the classical models, to introduce reliable models, and to indicate the steps we believe necessary to reach this target.

  7. Integrated optoelectronic oscillator.

    Science.gov (United States)

    Tang, Jian; Hao, Tengfei; Li, Wei; Domenech, David; Baños, Rocio; Muñoz, Pascual; Zhu, Ninghua; Capmany, José; Li, Ming

    2018-04-30

    With the rapid development of the modern communication systems, radar and wireless services, microwave signal with high-frequency, high-spectral-purity and frequency tunability as well as microwave generator with light weight, compact size, power-efficient and low cost are increasingly demanded. Integrated microwave photonics (IMWP) is regarded as a prospective way to meet these demands by hybridizing the microwave circuits and the photonics circuits on chip. In this article, we propose and experimentally demonstrate an integrated optoelectronic oscillator (IOEO). All of the devices needed in the optoelectronic oscillation loop circuit are monolithically integrated on chip within size of 5×6cm 2 . By tuning the injection current to 44 mA, the output frequency of the proposed IOEO is located at 7.30 GHz with phase noise value of -91 dBc/Hz@1MHz. When the injection current is increased to 65 mA, the output frequency can be changed to 8.87 GHz with phase noise value of -92 dBc/Hz@1MHz. Both of the oscillation frequency can be slightly tuned within 20 MHz around the center oscillation frequency by tuning the injection current. The method about improving the performance of IOEO is carefully discussed at the end of in this article.

  8. The variational spiked oscillator

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Ullah, N.

    1992-08-01

    A variational analysis of the spiked harmonic oscillator Hamiltonian -d 2 / d x 2 + x 2 + δ/ x 5/2 , δ > 0, is reported in this work. A trial function satisfying Dirichlet boundary conditions is suggested. The results are excellent for a large range of values of the coupling parameter. (author)

  9. Neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, L [European Organization for Nuclear Research, Geneva (Switzerland)

    1996-11-01

    Neutrino oscillation experiments ({nu}{sub {mu}}{yields}{nu}{sub e} and {nu}{sub {mu}}{yields}{nu}{sub {tau}}) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs.

  10. The moderated relationship of appearance valence on appearance self consciousness: development and testing of new measures of appearance schema components.

    Directory of Open Access Journals (Sweden)

    Timothy P Moss

    Full Text Available This paper describes the creation and psychometric properties of two independent measures of aspects of appearance schematicity--appearance salience and valence, assessed by the CARSAL and CARVAL, and their relation to appearance self-consciousness. Five hundred and ninety two participants provided data in a web based task. The results demonstrate the sound psychometric properties of both scales. This was demonstrated by good item total characteristics, good internal reliability of each scale, and the independence of the two scales shown through principal components analysis. Furthermore, the scales show independent and moderated relationships with valid measures of appearance related psychosocial distress. Negatively valenced appearance information was associated with increased appearance self-consciousness. More crucially, the impact of negative valence on appearance self-consciousness was exacerbated by the moderating effect increased salience of appearance.

  11. Anharmonic oscillator and Bogoliubov transformation

    International Nuclear Information System (INIS)

    Pattnayak, G.C.; Torasia, S.; Rath, B.

    1990-01-01

    The anharmonic oscillator occupies a cornerstone in many problems in physics. It was observed that none of the authors have tested Bogoliubov transformation to study anharmonic oscillator. The groundstate energy of the anharmonic oscillator is studied using Bogoliubov transformation and the results presented. (author)

  12. Bimodal oscillations in nephron autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular ...

  13. Observation and analysis of oscillations in linear accelerators

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1991-11-01

    This report discusses the following on oscillation in linear accelerators: Betatron Oscillations; Betatron Oscillations at High Currents; Transverse Profile Oscillations; Transverse Profile Oscillations at High Currents.; Oscillation and Profile Transient Jitter; and Feedback on Transverse Oscillations

  14. Electromagnetic damping of neutron star oscillations

    International Nuclear Information System (INIS)

    McDermott, P.N.; Savedoff, M.P.; Van Horn, H.M.; Zweibel, E.G.; Hansen, C.J.

    1984-01-01

    Nonradial pulsations of a neutron star with a strong dipole magnetic field cause emission of electromagnetic radiation. Here we compute the power radiated to vacuum by neutron star g-mode pulsations and by torsional oscillations of the neutron star crust. For the low-order quadrupole fluid g-modes we have considered, we find electromagnetic damping to be considerably more effective than gravitational radiation. For example, a 0.5 M/sub sun/ neutron star with a core temperature approx.10 7 K has a g 1 -mode period of 371 ms; for this mode were find the electromagnetic damping time to be tau/sub FM/approx.0.3 s, assuming the surface magnetic field strength of the neutron star to be B 0 approx.10 12 gauss. This is considerably less than the corresponding gravitational radiation time tau/sub GR/approx.3 x 10 17 yr. For dipole g-mode oscillations, there is no gravitational radiation, but electromagnetic damping and ohmic dissipation are efficient damping mechanisms. For dipole torsional oscillations, we find that electromagnetic damping again dominates, with tau/sub EM/approx.5 yr. Among the cases we have studied, quadrupole torsional oscillations appear to be dominated by gravitational radiation damping, with tau/sub GR/approx.10 4 yr, as compared with tau/sub EM/approx.2 x 10 7 yr

  15. Collective neutrino oscillations and neutrino wave packets

    Energy Technology Data Exchange (ETDEWEB)

    Akhmedov, Evgeny; Lindner, Manfred [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Kopp, Joachim, E-mail: akhmedov@mpi-hd.mpg.de, E-mail: jkopp@uni-mainz.de, E-mail: lindner@mpi-hd.mpg.de [PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Johannes Gutenberg University, 55099 Mainz (Germany)

    2017-09-01

    Effects of decoherence by wave packet separation on collective neutrino oscillations in dense neutrino gases are considered. We estimate the length of the wave packets of neutrinos produced in core collapse supernovae and the expected neutrino coherence length, and then proceed to consider the decoherence effects within the density matrix formalism of neutrino flavour transitions. First, we demonstrate that for neutrino oscillations in vacuum the decoherence effects are described by a damping term in the equation of motion of the density matrix of a neutrino as a whole (as contrasted to that of the fixed-momentum components of the neutrino density matrix). Next, we consider neutrino oscillations in ordinary matter and dense neutrino backgrounds, both in the adiabatic and non-adiabatic regimes. In the latter case we study two specific models of adiabaticity violation—one with short-term and another with extended non-adiabaticity. It is demonstrated that, while in the adiabatic case a damping term is present in the equation of motion of the neutrino density matrix (just like in the vacuum oscillation case), no such term in general appears in the non-adiabatic regime.

  16. Reactor oscillator - Proposal of the organisation for oscillator operation; Reaktorski oscilator - Predlog organizacije rada na oscilatoru

    Energy Technology Data Exchange (ETDEWEB)

    Lolic, B; Loloc, B [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    The organizational structure for operating the reactor with the reactor oscillator describes the duties of the reactor operators; staff responsible for operating the oscillator who are responsible for measurements, preparation of the samples and further treatment of the obtained results.

  17. Quenching oscillating behaviors in fractional coupled Stuart-Landau oscillators

    Science.gov (United States)

    Sun, Zhongkui; Xiao, Rui; Yang, Xiaoli; Xu, Wei

    2018-03-01

    Oscillation quenching has been widely studied during the past several decades in fields ranging from natural sciences to engineering, but investigations have so far been restricted to oscillators with an integer-order derivative. Here, we report the first study of amplitude death (AD) in fractional coupled Stuart-Landau oscillators with partial and/or complete conjugate couplings to explore oscillation quenching patterns and dynamics. It has been found that the fractional-order derivative impacts the AD state crucially. The area of the AD state increases along with the decrease of the fractional-order derivative. Furthermore, by introducing and adjusting a limiting feedback factor in coupling links, the AD state can be well tamed in fractional coupled oscillators. Hence, it provides one an effective approach to analyze and control the oscillating behaviors in fractional coupled oscillators.

  18. Pattern formation in arrays of chemical oscillators

    Indian Academy of Sciences (India)

    Chemical oscillators; phase flip; oscillation death. PACS No. 05.45 .... array oscillate (with varying amplitudes and frequencies), while the others experience oscillation death .... Barring the boundary cells, one observes near phase flip and near ...

  19. Atypical imaging appearances of intracranial meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, S. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom); Adams, W.M. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom); Parrish, R.W. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom); Mukonoweshuro, W. [Radiology Department, Derriford Hospital, Plymouth (United Kingdom)]. E-mail: William.mukonoweshuro@phnt.swest.nhs.uk

    2007-01-15

    Meningiomas are the commonest primary, non-glial intracranial tumours. The diagnosis is often correctly predicted from characteristic imaging appearances. This paper presents some examples of atypical imaging appearances that may cause diagnostic confusion.

  20. Entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, M.; Dell' Anno, F.; De Siena, S.; Illuminati, F. [Universita degli Studi di Salerno Via Ponte don Melillon, Dipt. di Matematica e Informatica, Fisciano SA (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno - Baronissi SA (Italy); Dell' Anno, F.; De Siena, S.; Illuminati, F. [CNR-INFM Coherentia - Napoli (Italy); Blasone, M. [ISI Foundation for Scientific Interchange, Torino (Italy)

    2009-03-15

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  1. Nonlinear (Anharmonic Casimir Oscillator

    Directory of Open Access Journals (Sweden)

    Habibollah Razmi

    2011-01-01

    Full Text Available We want to study the dynamics of a simple linear harmonic micro spring which is under the influence of the quantum Casimir force/pressure and thus behaves as a (an nonlinear (anharmonic Casimir oscillator. Generally, the equation of motion of this nonlinear micromechanical Casimir oscillator has no exact solvable (analytical solution and the turning point(s of the system has (have no fixed position(s; however, for particular values of the stiffness of the micro spring and at appropriately well-chosen distance scales and conditions, there is (are approximately sinusoidal solution(s for the problem (the variable turning points are collected in a very small interval of positions. This, as a simple and elementary plan, may be useful in controlling the Casimir stiction problem in micromechanical devices.

  2. Entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Blasone, M.; Dell'Anno, F.; De Siena, S.; Illuminati, F.; Dell'Anno, F.; De Siena, S.; Illuminati, F.; Blasone, M.

    2009-01-01

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  3. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  4. Discrete repulsive oscillator wavefunctions

    International Nuclear Information System (INIS)

    Munoz, Carlos A; Rueda-Paz, Juvenal; Wolf, Kurt Bernardo

    2009-01-01

    For the study of infinite discrete systems on phase space, the three-dimensional Lorentz algebra and group, so(2,1) and SO(2,1), provide a discrete model of the repulsive oscillator. Its eigenfunctions are found in the principal irreducible representation series, where the compact generator-that we identify with the position operator-has the infinite discrete spectrum of the integers Z, while the spectrum of energies is a double continuum. The right- and left-moving wavefunctions are given by hypergeometric functions that form a Dirac basis for l 2 (Z). Under contraction, the discrete system limits to the well-known quantum repulsive oscillator. Numerical computations of finite approximations raise further questions on the use of Dirac bases for infinite discrete systems.

  5. Neutrino Masses and Oscillations

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Treille, Daniel

    2002-01-01

    This course will not cover its subject in the customary way. The emphasis will be on the simple theoretical concepts (helicity, handedness, chirality, Majorana masses) which are obscure in most of the literature, and on the quantum mechanics of oscillations, that ALL books get wrong. Which, hopefully, will not deter me from discussing some of the most interesting results from the labs and from the cosmos.

  6. Oscillations in quasineutral plasmas

    International Nuclear Information System (INIS)

    Grenier, E.

    1996-01-01

    The purpose of this article is to describe the limit, as the vacuum electric permittivity goes to zero, of a plasma physics system, deduced from the Vlasov-Poisson system for special initial data (distribution functions which are analytic in the space variable, with compact support in velocity), a limit also called open-quotes quasineutral regimeclose quotes of the plasma, and the related oscillations of the electric field, with high frequency in time. 20 refs

  7. Density oscillations within hadrons

    International Nuclear Information System (INIS)

    Arnold, R.; Barshay, S.

    1976-01-01

    In models of extended hadrons, in which small bits of matter carrying charge and effective mass exist confined within a medium, oscillations in the matter density may occur. A way of investigating this possibility experimentally in high-energy hadron-hadron elastic diffraction scattering is suggested, and the effect is illustrated by examining some existing data which might be relevant to the question [fr

  8. Neutrino Oscillations Physics

    Science.gov (United States)

    Fogli, Gianluigi

    2005-06-01

    We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

  9. Electron Neutrino and Antineutrino Appearance in the MINOS Detector

    Energy Technology Data Exchange (ETDEWEB)

    Schreckenberger, Adam Paul [Univ. of Minnesota, Minneapolis, MN (United States)

    2013-04-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline neutrino experiment that utilizes a particle beam and two steel-scintillator calorimeters designed to determine the parameters associated with muon neutrino disappearance. Analysis methods developed by the MINOS νe group have facilitated the placement of limits upon the mixing angle associated with νμ → νe oscillations. Since the polarity of the focusing horns can be switched, we can perform a similar analysis with an antineutrino-enriched beam to select electron antineutrino appearance candidates. Using 3.34e20 POT (protons on target) in the antineutrino mode, we exclude θ13 = 0 at the 80% C.L. A joint fit of the 3.34e20 POT antineutrino and 10.6e20 POT neutrino samples excluded θ13 = 0 at the 96% C.L. In addition, the combined data were used to produce exclusions regarding the CP-violating phase.

  10. The CT appearance of intraoral chewing gum

    International Nuclear Information System (INIS)

    Towbin, Alexander J.

    2008-01-01

    When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

  11. The CT appearance of intraoral chewing gum

    Energy Technology Data Exchange (ETDEWEB)

    Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2008-12-15

    When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

  12. Sun oscillations and the problem of its internal structure

    International Nuclear Information System (INIS)

    Severnyj, A.B.; Kotov, V.A.; Tsap, T.T.

    1979-01-01

    Analysis of global solar oscillation measurements for five years (1974-1978, more than 1000 hours of observations, 215 days) is given. It is shown that the period of oscillations is 160sup(m)x0.10+-0sup(m)x004 and the amplitude is 1 m/s. The phases of oscillations, obtained at the Crimea, Stanford, Kitt Peak and Pic du Midi, are in good agreement, thus making the assumption on ''telluric origin'' of the oscillations improbable. It has been found: 1) slow, synchronous (at Crimea and Stanford) drift of the phase of velocity maximum from year to year and 2) the dependence of amplitude on the phase of 27-day rotational period of the Sun which favours the assumption on the quadrupole character of oscillations. It is pointed out that these facts, as well as the absence of oscillation waves in the telluric line observed simultaneously with the solar line, exclude the possibility of explaining the results as a statistical artifact. It has also been shown that the differential extinction effect produces an oscillation effect which is by an order of magnitude lower than the observed one. The following preliminary results are noted: a) the appearance of synchronous oscillations of the mean solar magnetic field of the brightness of the Sun and of the solar radio emission; b) the disappearance of the oscillations from time to time, possibly due to the effect of the supergranulation passage across the solar disk. The oscillations observed imply new important restrictions on the problem of the internal constitution of the Sun, and point to the possibility of non-radiative heat-transfer inside the Sun which might help the solution of the low neutrino flux problem

  13. Rabi oscillations a quantum dot exposed to quantum light

    International Nuclear Information System (INIS)

    Magyarov, A.; Slepyan, G.Ya.; Maksimenko, S.A.; Hoffmann, A.

    2007-01-01

    The influence of the local field on the excitonic Rabi oscillations in an isolated quantum dot driven by the coherent state of light has been theoretically investigated. Local field is predicted to entail the appearance of two oscillatory regimes in the Rabi effect separated by the bifurcation. In the first regime Rabi oscillations are periodic and do not reveal collapse-revivals phenomenon, while in the second one collapse and revivals appear, showing significant difference as compared to those predicted by the standard Jaynes-Cummings model

  14. Quantitative Appearance Inspection for Film Coated Tablets.

    Science.gov (United States)

    Yoshino, Hiroyuki; Yamashita, Kazunari; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

    2016-01-01

    The decision criteria for the physical appearance of pharmaceutical products are subjective and qualitative means of evaluation that are based entirely on human interpretation. In this study, we have developed a comprehensive method for the quantitative analysis of the physical appearance of film coated tablets. Three different kinds of film coated tablets with considerable differences in their physical appearances were manufactured as models, and their surface roughness, contact angle, color measurements and physicochemical properties were investigated as potential characteristics for the quantitative analysis of their physical appearance. All of these characteristics were useful for the quantitative evaluation of the physical appearances of the tablets, and could potentially be used to establish decision criteria to assess the quality of tablets. In particular, the analysis of the surface roughness and film coating properties of the tablets by terahertz spectroscopy allowed for an effective evaluation of the tablets' properties. These results indicated the possibility of inspecting the appearance of tablets during the film coating process.

  15. Designing visual appearance using a structured surface

    DEFF Research Database (Denmark)

    Johansen, Villads Egede; Thamdrup, Lasse Højlund; Smitrup, Christian

    2015-01-01

    followed by numerical and experimental verification. The approach comprises verifying all design and fabrication steps required to produce a desired appearance. We expect that the procedure in the future will yield structurally colored surfaces with appealing prescribed visual appearances.......We present an approach for designing nanostructured surfaces with prescribed visual appearances, starting at design analysis and ending with a fabricated sample. The method is applied to a silicon wafer structured using deep ultraviolet lithography and dry etching and includes preliminary design...

  16. Using Fast Vibrations to Quench Friction-induced Oscillations

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    1999-01-01

    -ity corresponding to the minimum kinetic coefficient of friction. Simple expressions are given also for predicting the excitation necessary for quenching self-excited oscillations at or below a specified belt velocity. These and other results contribute to the general understanding of how friction properties may......This work examines how friction-induced self-excited oscillations are affected by high-frequency ex-ternal excitation. Simple analytical approximations are derived for predicting the occurence of self-excited oscillations for the traditional mass-on-moving-belt model – with and without high......-frequency excitation. It appears that high-frequency excitation can effectively cancel the negative slope in the friction-velocity relationship, and may thus prevent self-excited oscillations. To accomplish this it is sufficient that the (nondimensional) product of excitation amplitude and frequency exceeds the veloc...

  17. Golden quantum oscillator and Binet–Fibonacci calculus

    International Nuclear Information System (INIS)

    Pashaev, Oktay K; Nalci, Sengul

    2012-01-01

    The Binet formula for Fibonacci numbers is treated as a q-number and a q-operator with Golden ratio bases q = φ and Q = −1/φ, and the corresponding Fibonacci or Golden calculus is developed. A quantum harmonic oscillator for this Golden calculus is derived so that its spectrum is given only by Fibonacci numbers. The ratio of successive energy levels is found to be the Golden sequence, and for asymptotic states in the limit n → ∞ it appears as the Golden ratio. We call this oscillator the Golden oscillator. Using double Golden bosons, the Golden angular momentum and its representation in terms of Fibonacci numbers and the Golden ratio are derived. Relations of Fibonacci calculus with a q-deformed fermion oscillator and entangled N-qubit states are indicated. (paper)

  18. Parametric Resonance in a Time-Dependent Harmonic Oscillator

    Directory of Open Access Journals (Sweden)

    P. N. Nesterov

    2013-01-01

    Full Text Available In this paper, we study the phenomenon of appearance of new resonances in a timedependent harmonic oscillator under an oscillatory decreasing force. The studied equation belongs to the class of adiabatic oscillators and arises in connection with the spectral problem for the one-dimensional Schr¨odinger equation with Wigner–von Neumann type potential. We use a specially developed method for asymptotic integration of linear systems of differential equations with oscillatory decreasing coefficients. This method uses the ideas of the averaging method to simplify the initial system. Then we apply Levinson’s fundamental theorem to get the asymptotics for its solutions. Finally, we analyze the features of a parametric resonance phenomenon. The resonant frequencies of perturbation are found and the pointwise type of the parametric resonance phenomenon is established. In conclusion, we construct an example of a time-dependent harmonic oscillator (adiabatic oscillator in which the parametric resonances, mentioned in the paper, may occur.

  19. Golden quantum oscillator and Binet-Fibonacci calculus

    Energy Technology Data Exchange (ETDEWEB)

    Pashaev, Oktay K; Nalci, Sengul, E-mail: oktaypashaev@iyte.edu.tr [Department of Mathematics, Izmir Institute of Technology, Urla-Izmir 35430 (Turkey)

    2012-01-13

    The Binet formula for Fibonacci numbers is treated as a q-number and a q-operator with Golden ratio bases q = {phi} and Q = -1/{phi}, and the corresponding Fibonacci or Golden calculus is developed. A quantum harmonic oscillator for this Golden calculus is derived so that its spectrum is given only by Fibonacci numbers. The ratio of successive energy levels is found to be the Golden sequence, and for asymptotic states in the limit n {yields} {infinity} it appears as the Golden ratio. We call this oscillator the Golden oscillator. Using double Golden bosons, the Golden angular momentum and its representation in terms of Fibonacci numbers and the Golden ratio are derived. Relations of Fibonacci calculus with a q-deformed fermion oscillator and entangled N-qubit states are indicated. (paper)

  20. ELMy-H mode as limit cycle and chaotic oscillations in tokamak plasmas

    International Nuclear Information System (INIS)

    Itoh, Sanae; Itoh, Kimitaka; Fukuyama, Atsushi.

    1991-06-01

    A model of Edge Localized Modes (ELMs) in tokamaks is presented. A limit cycle solution is found in time-dependent Ginzburg Landau type model equation of L/H transition, which has a hysteresis curve between the plasma gradient and flux. The oscillation of edge density appears near the L/H transition boundary. Spatial structure of the intermediate state (mesophase) is obtained in the edge region. Chaotic oscillation is predicted due to random neutrals and external oscillations. (author)

  1. Observation of a new plasma regime with stationary electron temperature oscillations on Tore Supra

    International Nuclear Information System (INIS)

    Artaud, J.F.; Giruzzi, G.; Imbeaux, F.; Segui, J.L.; Garbet, X.

    2003-01-01

    This document is a copy of the slides presented on the 9. joint US-European Transport Task Force meeting. The first part is devoted to the experimental observations of a new tokamak plasma regime with stationary electron temperature oscillations. The oscillations appear on ECE spontaneously, sometimes associated with a transition to the LHEP regime. The second part presents an interpretation of these oscillations by analogy with a predator-prey system. (A.L.B.)

  2. Quasioptical Josephson oscillator

    International Nuclear Information System (INIS)

    Wengler, M.J.; Pance, A.; Liu, B.

    1991-01-01

    This paper discusses the authors' work with large 2-dimensional arrays of Josephson junctions for submillimeter power generation. The basic design of the Quasioptical Josephson Oscillator (QJO) is presented. The reasons for each design decision are discussed. Superconducting devices have not yet been fabricated, but scale models and computer simulations have been done. A method for characterizing array rf coupling structures is described, and initial results with this method are presented. Microwave scale models of the radiation structure are built and a series of measurements are made with a network analyzer

  3. Modeling microtubule oscillations

    DEFF Research Database (Denmark)

    Jobs, E.; Wolf, D.E.; Flyvbjerg, H.

    1997-01-01

    Synchronization of molecular reactions in a macroscopic volume may cause the volume's physical properties to change dynamically and thus reveal much about the reactions. As an example, experimental time series for so-called microtubule oscillations are analyzed in terms of a minimal model...... for this complex polymerization-depolymerization cycle. The model reproduces well the qualitatively different time series that result from different experimental conditions, and illuminates the role and importance of individual processes in the cycle. Simple experiments are suggested that can further test...... and define the model and the polymer's reaction cycle....

  4. Oscillations in nonlinear systems

    CERN Document Server

    Hale, Jack K

    2015-01-01

    By focusing on ordinary differential equations that contain a small parameter, this concise graduate-level introduction to the theory of nonlinear oscillations provides a unified approach to obtaining periodic solutions to nonautonomous and autonomous differential equations. It also indicates key relationships with other related procedures and probes the consequences of the methods of averaging and integral manifolds.Part I of the text features introductory material, including discussions of matrices, linear systems of differential equations, and stability of solutions of nonlinear systems. Pa

  5. Neutrino oscillations at LAMPF

    International Nuclear Information System (INIS)

    Carlini, R.; Choi, C.; Donohue, J.

    1985-01-01

    Work at Argonne continues on the construction of the neutrino oscillation experiment (E645). Construction of detector supports and active shield components were completed at the Provo plant of the principal contractor for the project (the Pittsburgh-Des Moines Corporation). Erection of the major experimental components was completed at the LAMPF experimental site in mid-March 1985. Work continues on the tunnel which will house the detector. Construction of detector components (scintillators and proportional drift tubes) is proceeding at Ohio State University and Louisiana State University. Consolidation of these components into the 20-ton neutrino detector is beginning at LAMPF

  6. Theory of oscillators

    CERN Document Server

    Andronov, Aleksandr Aleksandrovich; Vitt, Aleksandr Adolfovich

    1966-01-01

    Theory of Oscillators presents the applications and exposition of the qualitative theory of differential equations. This book discusses the idea of a discontinuous transition in a dynamic process. Organized into 11 chapters, this book begins with an overview of the simplest type of oscillatory system in which the motion is described by a linear differential equation. This text then examines the character of the motion of the representative point along the hyperbola. Other chapters consider examples of two basic types of non-linear non-conservative systems, namely, dissipative systems and self-

  7. Solar and stellar oscillations

    International Nuclear Information System (INIS)

    Fossat, E.

    1981-01-01

    We try to explain in simple words what a stellar oscillation is, what kind of restoring forces and excitation mechanisms can be responsible for its occurence, what kind of questions the theoretician asks to the observer and what kind of tools the latter is using to look for the answers. A selected review of the most striking results obtained in the last few years in solar seismology and the present status of their consequences on solar models is presented. A brief discussion on the expected extension towards stellar seismology will end the paper. A selected bibliography on theory as well as observations and recent papers is also included. (orig.)

  8. Coupled nonlinear oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, J; Scott, A C

    1983-01-01

    Topics discussed include transitions in weakly coupled nonlinear oscillators, singularly perturbed delay-differential equations, and chaos in simple laser systems. Papers are presented on truncated Navier-Stokes equations in a two-dimensional torus, on frequency locking in Josephson point contacts, and on soliton excitations in Josephson tunnel junctions. Attention is also given to the nonlinear coupling of radiation pulses to absorbing anharmonic molecular media, to aspects of interrupted coarse-graining in stimulated excitation, and to a statistical analysis of long-term dynamic irregularity in an exactly soluble quantum mechanical model.

  9. Brain Oscillations, Hypnosis, and Hypnotizability.

    Science.gov (United States)

    Jensen, Mark P; Adachi, Tomonori; Hakimian, Shahin

    2015-01-01

    This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis, specifically, that the increases in theta oscillations and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.

  10. Bounded-oscillation Pushdown Automata

    Directory of Open Access Journals (Sweden)

    Pierre Ganty

    2016-09-01

    Full Text Available We present an underapproximation for context-free languages by filtering out runs of the underlying pushdown automaton depending on how the stack height evolves over time. In particular, we assign to each run a number quantifying the oscillating behavior of the stack along the run. We study languages accepted by pushdown automata restricted to k-oscillating runs. We relate oscillation on pushdown automata with a counterpart restriction on context-free grammars. We also provide a way to filter all but the k-oscillating runs from a given PDA by annotating stack symbols with information about the oscillation. Finally, we study closure properties of the defined class of languages and the complexity of the k-emptiness problem asking, given a pushdown automaton P and k >= 0, whether P has a k-oscillating run. We show that, when k is not part of the input, the k-emptiness problem is NLOGSPACE-complete.

  11. Single ICCII Sinusoidal Oscillators Employing Grounded Capacitors

    Directory of Open Access Journals (Sweden)

    J. W. Horng

    2011-09-01

    Full Text Available Two inverting second-generation current conveyors (ICCII based sinusoidal oscillators are presented. The first sinusoidal oscillator is composed of one ICCII, two grounded capacitors and two resistors. The oscillation condition and oscillation frequency can be orthogonally controllable. The second sinusoidal oscillator is composed of one ICCII, two grounded capacitors and three resistors. The oscillation condition and oscillation frequency can be independently controllable through different resistors.

  12. Stable And Oscillating Acoustic Levitation

    Science.gov (United States)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  13. Isotropic oscillator: spheroidal wave functions

    International Nuclear Information System (INIS)

    Mardoyan, L.G.; Pogosyan, G.S.; Ter-Antonyan, V.M.; Sisakyan, A.N.

    1985-01-01

    Solutions of the Schroedinger equation are found for an isotropic oscillator (10) in prolate and oblate spheroidal coordinates. It is shown that the obtained solutions turn into spherical and cylindrical bases of the isotropic oscillator at R→0 and R→ infinity (R is the dimensional parameter entering into the definition of prolate and oblate spheroidal coordinates). The explicit form is given for both prolate and oblate basis of the isotropic oscillator for the lowest quantum states

  14. Neutrino oscillations. Theory and experiment

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    2001-01-01

    Theoretical schemes on neutrino oscillations are considered. The experimental data on neutrino oscillations obtained in the Super-Kamiokande (Japan) and SNO (Canada) experiments are given. Comparison of these data with the predictions obtained in the theoretical schemes is done. Conclusion is made that the experimental data confirm only the scheme with transitions (oscillations) between aromatic ν e -, ν μ -, ν τ - neutrinos with maximal angle mixings. (author)

  15. Neuronal ensemble for visual working memory via interplay of slow and fast oscillations.

    Science.gov (United States)

    Mizuhara, Hiroaki; Yamaguchi, Yoko

    2011-05-01

    The current focus of studies on neural entities for memory maintenance is on the interplay between fast neuronal oscillations in the gamma band and slow oscillations in the theta or delta band. The hierarchical coupling of slow and fast oscillations is crucial for the rehearsal of sensory inputs for short-term storage, as well as for binding sensory inputs that are represented in spatially segregated cortical areas. However, no experimental evidence for the binding of spatially segregated information has yet been presented for memory maintenance in humans. In the present study, we actively manipulated memory maintenance performance with an attentional blink procedure during human scalp electroencephalography (EEG) recordings and identified that slow oscillations are enhanced when memory maintenance is successful. These slow oscillations accompanied fast oscillations in the gamma frequency range that appeared at spatially segregated scalp sites. The amplitude of the gamma oscillation at these scalp sites was simultaneously enhanced at an EEG phase of the slow oscillation. Successful memory maintenance appears to be achieved by a rehearsal of sensory inputs together with a coordination of distributed fast oscillations at a preferred timing of the slow oscillations. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  16. Malignant Lesions as Mammographically Appearing Intramammary Ganglia

    International Nuclear Information System (INIS)

    Martinez-Miraveta, P.; Pons, M. J.; Pina, L. J.; Zornoza, G.

    2004-01-01

    Intramammary ganglia are frequent mammographic findings of no pathological importance. We present two cases of malignant breast lesions whose mammographic appearance could resemble that of intramammary ganglia. Although the mammographic appearance of a lesion is similar to that of intramammary ganglia, it should be carefully studied, especially if it presents a poorly defined border or is palpable. (Author)

  17. 29 CFR 1921.10 - Appearances.

    Science.gov (United States)

    2010-07-01

    ... Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) RULES OF PRACTICE IN ENFORCEMENT PROCEEDINGS UNDER SECTION 41 OF THE LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT Hearing and Related Matters § 1921.10 Appearances. (a) Representation. The parties may appear...

  18. 39 CFR 953.7 - Default; Appearances.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Default; Appearances. 953.7 Section 953.7 Postal... § 953.7 Default; Appearances. If a timely reply to the appeal is not filed, the presiding officer shall... Inspector or his or her designee is in default. Whenever the General Counsel or the Chief Postal Inspector...

  19. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsen, Rasmus

    2003-01-01

    the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...

  20. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsen, Rasmus

    2002-01-01

    the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...

  1. Interactive Appearance Prediction for Cloudy Beverages

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Frisvad, Jeppe Revall; Kjeldsen, Thomas Kim

    2016-01-01

    Juice appearance is important to consumers, so digital juice with a slider that varies a production parameter or changes juice content is useful. It is however challenging to render juice with scattering particles quickly and accurately. As a case study, we create an appearance model that provide...

  2. Chemotaxis and Actin Oscillations

    Science.gov (United States)

    Bodenschatz, Eberhard; Hsu, Hsin-Fang; Negrete, Jose; Beta, Carsten; Pumir, Alain; Gholami, Azam; Tarantola, Marco; Westendorf, Christian; Zykov, Vladimir

    Recently, self-oscillations of the cytoskeletal actin have been observed in Dictyostelium, a model system for studying chemotaxis. Here we report experimental results on the self-oscillation mechanism and the role of regulatory proteins and myosin II. We stimulate cells rapidly and periodically by using photo un-caging of the chemoattractant in a micro-fluidic device and measured the cellular responses. We found that the response amplitude grows with stimulation strength only in a very narrow region of stimulation, after which the response amplitude reaches a plateau. Moreover, the frequency-response is not constant but rather varies with the strength of external stimuli. To understand the underlying mechanism, we analyzed the polymerization and de-polymerization time in the single cell level. Despite of the large cell-to-cell variability, we found that the polymerization time is independent of external stimuli and the de-polymerization time is prolonged as the stimulation strength increases. Our conclusions will be summarized and the role of noise in the signaling network will be discussed. German Science Foundation CRC 937.

  3. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic of the ampli......A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  4. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  5. Heat exchanger with oscillating flow

    Science.gov (United States)

    Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)

    1993-01-01

    Various heat exchange apparatuses are described in which an oscillating flow of primary coolant is used to dissipate an incident heat flux. The oscillating flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic oscillators or electromagnetic pumps. The oscillating fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.

  6. Search for Muon neutrino → Tau neutrino oscillations motivation and feasibility

    International Nuclear Information System (INIS)

    Zacek, V.

    1988-01-01

    Theoretical prejudices derived from solar-neutrino matter oscillations and assumptions of neutrino mass hierarchies suggest, that neutrino-oscillations are observable in laboratory with mass parameters of Δm 2 = 10 -3 -10 4 eV 2 . In particular Muon neutrino → Tau neutrino appearance searches at accelerators seem strongly motivated

  7. Photoelectric observations of propagating sunspot oscillations

    International Nuclear Information System (INIS)

    Lites, B.W.; White, O.R.; Packman, D.

    1982-01-01

    The Sacramento Park Observatory Vacuum Tower Telescope and diode array were used to make repeated intensity and velocity images of a large, isolated sunspot in both a chromospheric (lambda8542 Ca II) and a photospheric (lambda5576 Fe I) line. The movie of the digital data for the chromospheric line shows clearly a relationship between the propagating umbral disturbances and the running penumbral waves. The velocities for transverse propagating of the umbral and penumbral disturbances are 60--70 km s -1 and 20--35 km s -1 , respectively. Power spectra of the oscillations show a sharp peak at a period of about 170 s in both the velocity and intensity signals. The rms velocity fluctuation of this power peak is 0.26 km s -1 . The oscillations at any given point in the sunspot are very regular, and the phase relationship between the velocity and intensity of the chromospheric oscillations is radically different than that for the quiet Sun. Our preliminary interpretation of the phase relationship involves acoustic waves with wave vector directed downwards along the magnetic field lines; however, this interpretation relies on assumptions involved in the data reduction scheme. The mechanical energy flux carried by the observed umbral disturbances does not appear to be a significant contributor to the overall energy budget of the sunspot or the surrounding active region

  8. Struma ovarii. MR and CT appearance

    International Nuclear Information System (INIS)

    Joja, Ikuo; Mitsumori, Akihito; Hiraki, Yoshio; Kudo, Takafumi; Nakagawa, Tomio; Asakawa, Toru; Ando, Masaaki; Akamatsu, Nobuo.

    1997-01-01

    The purpose of this study was to examine the appearance of struma ovarii on MR and CT images. All 13 patients showed both cystic and solid components with a multilobulated surface and thickened septa. Various signal intensities were seen on both T1WI and T2WI. The cystic component, which showed low signal intensity on T2WI, showed high density on CT images. The characteristic MR and CT appearance of struma ovarii appears to be that of multicystic tumor indicating the presence of viscid materials containing iodine. (author)

  9. Reactor oscillator - I - III, Part I

    International Nuclear Information System (INIS)

    Lolic, B.

    1961-12-01

    Project 'Reactor oscillator' covers the following activities: designing reactor oscillators for reactors RA and RB with detailed engineering drawings; constructing and mounting of the oscillator; designing and constructing the appropriate electronic equipment for the oscillator; measurements at the RA and RB reactors needed for completing the oscillator construction

  10. Weiss oscillations in the electronic structure of modulated graphene

    International Nuclear Information System (INIS)

    Tahir, M; Sabeeh, K; MacKinnon, A

    2007-01-01

    We present a theoretical study of the electronic structure of modulated graphene in the presence of a perpendicular magnetic field. The density of states and the bandwidth for the Dirac electrons in this system are determined. The appearance of unusual Weiss oscillations in the bandwidth and density of states is the main focus of this work

  11. A Look at Damped Harmonic Oscillators through the Phase Plane

    Science.gov (United States)

    Daneshbod, Yousef; Latulippe, Joe

    2011-01-01

    Damped harmonic oscillations appear naturally in many applications involving mechanical and electrical systems as well as in biological systems. Most students are introduced to harmonic motion in an elementary ordinary differential equation (ODE) course. Solutions to ODEs that describe simple harmonic motion are usually found by investigating the…

  12. Time domain oscillating poles: Stability redefined in Memristor based Wien-oscillators

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    poles. The idea is verified using a Memristor based Wien oscillator. Sustained oscillations are observed without having the poles of the system fixed on the imaginary axis and the oscillating behavior of the system poles is reported. The oscillating

  13. Damping of Coherent oscillations

    CERN Document Server

    Vos, L

    1996-01-01

    Damping of coherent oscillations by feedback is straightforward in principle. It has been a vital ingredient for the safe operation of accelerators since a long time. The increasing dimensions and beam intensities of the new generation of hadron colliders impose unprecedented demands on the performance of future systems. The arguments leading to the specification of a transverse feedback system for the CERN SPS in its role as LHC injector and the LHC collider itself are developped to illustrate this. The preservation of the transverse emittance is the guiding principle during this exercise keeping in mind the hostile environment which comprises: transverse impedance bent on developping coupled bunch instabilities, injection errors, unwanted transverse excitation, unavoidable tune spreads and noise in the damping loop.

  14. Convection and stellar oscillations

    DEFF Research Database (Denmark)

    Aarslev, Magnus Johan

    2017-01-01

    for asteroseismology, because of the challenges inherent in modelling turbulent convection in 1D stellar models. As a result of oversimplifying the physics near the surface, theoretical calculations systematically overestimate the oscillation frequencies. This has become known as the asteroseismic surface effect. Due...... to lacking better options, this frequency difference is typically corrected for with ad-hoc formulae. The topic of this thesis is the improvement of 1D stellar convection models and the effects this has on asteroseismic properties. The source of improvements is 3D simulations of radiation...... atmospheres to replace the outer layers of stellar models. The additional turbulent pressure and asymmetrical opacity effects in the atmosphere model, compared to convection in stellar evolution models, serve to expand the atmosphere. The enlarged acoustic cavity lowers the pulsation frequencies bringing them...

  15. Photospheric oscillations. Pt. 1

    International Nuclear Information System (INIS)

    Fossat, E.; Ricort, G.

    1975-01-01

    Intensity fluctuations in the wings of the Fraunhofer line Na D 1 5896 have been recorded for about two hundred hours at the focus of the Nice coude refractor, using a sodium optical resonance device. Because of the large beam aperture available, records have been made on circular apertures from 22'' up to 32' diameter (the whole sun). The principal results from the analysis of these date are: As shown by White and Cha, the five-minute oscillation has a gaussian random character with a mean lifetime of about 20 min. Its two-dimensional spatial power spectrum is roughly gaussian for every temporal frequency between 2 and 6 MHz. The width of this gaussian spectrum is near 5 x 10 -5 km -1 (i.e. π = 20,000 km). (orig./BJ) [de

  16. Coronal Waves and Oscillations

    Directory of Open Access Journals (Sweden)

    Nakariakov Valery M.

    2005-07-01

    Full Text Available Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves, theoretical modelling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.

  17. Appearance is a function of the face.

    Science.gov (United States)

    Borah, Gregory L; Rankin, Marlene K

    2010-03-01

    Increasingly, third-party insurers deny coverage to patients with posttraumatic and congenital facial deformities because these are not seen as "functional." Recent facial transplants have demonstrated that severely deformed patients are willing to undergo potentially life-threatening surgery in search of a normal physiognomy. Scant quantitative research exists that objectively documents appearance as a primary "function" of the face. This study was designed to establish a population-based definition of the functions of the human face, rank importance of the face among various anatomical areas, and determine the risk value the average person places on a normal appearance. Voluntary adult subjects (n = 210) in three states aged 18 to 75 years were recruited using a quota sampling technique. Subjects completed study questionnaires of demography and bias using the Gamble Chance of Death Questionnaire and the Rosenberg Self-Esteem Scale. The face ranked as the most important anatomical area for functional reconstruction. Appearance was the fifth most important function of the face, after breathing, sight, speech, and eating. Normal facial appearance was rated as very important for one to be a functioning member of American society (p = 0.01) by 49 percent. One in seven subjects (13 percent) would accept a 30 to 45 percent risk of death to obtain a "normal" face. Normal appearance is a primary function of the face, based on a large, culturally diverse population sample across the lifespan. Normal appearance ranks above smell and expression as a function. Restoration of facial appearance is ranked the most important anatomical area for repair. Normal facial appearance is very important for one to be a functional member of American society.

  18. Angiographic appearances of rare renal tumours

    International Nuclear Information System (INIS)

    Schmidt, M.; Taenzer, V.

    1980-01-01

    Oncocytomas, called oxyphil proximal tubular adenomas in the Anglo Saxon literature, and benign hypernephromas are non-malignant, usually symptomless, rare tumours belonging to the renal adenomas. Oncocytomas have angiographic appearances sufficiently uniform to permit a tentative diagnosis. Histologically benign hypernephromas do not possess characteristic angiographic appearances and, in the presence of tumour in the renal vein or necrotic avascular areas, must be regarded as potentially malignant. (orig.) [de

  19. Oscillator strengths for neutral technetium

    International Nuclear Information System (INIS)

    Garstang, R.H.

    1981-01-01

    Oscillator strengths have been calculated for most of the spectral lines of TcI which are of interest in the study of stars of spectral type S. Oscillator strengths have been computed for the corresponding transitions in MnI as a partial check of the technetium calculations

  20. Hyperchaos in coupled Colpitts oscillators

    DEFF Research Database (Denmark)

    Cenys, Antanas; Tamasevicius, Arunas; Baziliauskas, Antanas

    2003-01-01

    The paper suggests a simple solution of building a hyperchaotic oscillator. Two chaotic Colpitts oscillators, either identical or non-identical ones are coupled by means of two linear resistors R-k. The hyperchaotic output signal v(t) is a linear combination, specifically the mean of the individual...

  1. Stochastic and Chaotic Relaxation Oscillations

    NARCIS (Netherlands)

    Grasman, J.; Roerdink, J.B.T.M.

    1988-01-01

    For relaxation oscillators stochastic and chaotic dynamics are investigated. The effect of random perturbations upon the period is computed. For an extended system with additional state variables chaotic behavior can be expected. As an example, the Van der Pol oscillator is changed into a

  2. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    ... are derived, and the relevant properties and features of oscillating solitons are illustrated. Oscillating solitons are controlled by the reciprocal of the group velocity and Kerr nonlinearity. Results of this paper will be valuable to the study of dispersion-managed optical communication system and mode-locked fibre lasers.

  3. Augmenting cognition by neuronal oscillations

    NARCIS (Netherlands)

    Horschig, J.M.; Zumer, J.; Bahramisharif, A.

    2014-01-01

    Cortical oscillations have been shown to represent fundamental functions of a working brain, e.g., communication, stimulus binding, error monitoring, and inhibition, and are directly linked to behavior. Recent studies intervening with these oscillations have demonstrated effective modulation of both

  4. Mammographic appearances of male breast disease.

    Science.gov (United States)

    Appelbaum, A H; Evans, G F; Levy, K R; Amirkhan, R H; Schumpert, T D

    1999-01-01

    Various male breast diseases have characteristic mammographic appearances that can be correlated with their pathologic diagnoses. Male breast cancer is usually subareolar and eccentric to the nipple. Margins of the lesions are more frequently well defined, and calcifications are rarer and coarser than those occurring in female breast cancer. Gynecomastia usually appears as a fan-shaped density emanating from the nipple, gradually blending into surrounding fat. It may have prominent extensions into surrounding fat and, in some cases, an appearance similar to that of a heterogeneously dense female breast. Although there are characteristic mammographic features that allow breast cancer in men to be recognized, there is substantial overlap between these features and the mammographic appearance of benign nodular lesions. The mammographic appearance of gynecomastia is not similar to that of male breast cancer, but in rare cases, it can mask malignancy. Gynecomastia can be mimicked by chronic inflammation. All mammographically lucent lesions of the male breast appear to be benign, similar to such lesions in the female breast.

  5. Oscillating universe with quintom matter

    International Nuclear Information System (INIS)

    Xiong Huahui; Cai Yifu; Qiu Taotao; Piao Yunsong; Zhang Xinmin

    2008-01-01

    In this Letter, we study the possibility of building a model of the oscillating universe with quintom matter in the framework of 4-dimensional Friedmann-Robertson-Walker background. Taking the two-scalar-field quintom model as an example, we find in the model parameter space there are five different types of solutions which correspond to: (I) a cyclic universe with the minimal and maximal values of the scale factor remaining the same in every cycle, (II) an oscillating universe with its minimal and maximal values of the scale factor increasing cycle by cycle, (III) an oscillating universe with its scale factor always increasing, (IV) an oscillating universe with its minimal and maximal values of the scale factor decreasing cycle by cycle, and (V) an oscillating universe with its scale factor always decreasing

  6. Synchronisation Induced by Repulsive Interactions in a System of van der Pol Oscillators

    Science.gov (United States)

    Martins, T. V.; Toral, R.

    2011-09-01

    We consider a system of identical van der Pol oscillators, globally coupled through their velocities, and study how the presence of competitive interactions affects its synchronisation properties. We will address the question from two points of view. Firstly, we will investigate the role of competitive interactions on the synchronisation among identical oscillators. Then, we will show that the presence of a fraction of repulsive links results in the appearance of macroscopic oscillations at that signal's rhythm, in regions where the individual oscillator is unable to synchronise with a weak external signal.

  7. Free oscillation of the Earth

    Directory of Open Access Journals (Sweden)

    Y. Abedini

    2000-06-01

    Full Text Available   This work is a study of the Earths free oscillations considering a merge of solid and liquid model. At the turn of 19th century Geophysicists presented the theory of the free oscillations for a self-gravitating, isotropic and compressible sphere. Assuming a steel structure for an Earth size sphere, they predicted a period of oscillation of about 1 hour. About 50 years later, the free oscillations of stars was studied by Cowling and others. They classified the oscillation modes of the stars into acoustic and gravity modes on the basis of their driving forces. These are pressure and buoyancy forces respectively. The earliest measurements for the period of the free oscillations of the Earth was made by Benyove from a study of Kamchathca earthquake. Since then, the Geophysicists have been trying to provide a theoretical basis for these measurements. Recently, the theory concerning oscillations of celestial fluids is extended by Sobouti to include the possible oscillations of the Earthlike bodies. Using the same technique, we study the free oscillations of a spherically symmetric, non-rotating and elastic model for the Earth.   We used the actual data of the Earths interior structure in our numerical calculations. Numerical results show that there exist three distinct oscillation modes namely acoustic, gravity and toroidal modes. These modes are driven by pressure, buoyancy and shear forces respectively. The shear force is due to the elastic properties of the solid part of the Earth. Our numerical results are consistent with the seismic data recorded from earthquake measurements.

  8. Alcohol brand appearances in US popular music.

    Science.gov (United States)

    Primack, Brian A; Nuzzo, Erin; Rice, Kristen R; Sargent, James D

    2012-03-01

    The average US adolescent is exposed to 34 references to alcohol in popular music daily. Although brand recognition is an independent, potent risk factor for alcohol outcomes among adolescents, alcohol brand appearances in popular music have not been assessed systematically. We aimed to determine the prevalence of and contextual elements associated with alcohol brand appearances in US popular music. Qualitative content analysis. We used Billboard Magazine to identify songs to which US adolescents were most exposed in 2005-07. For each of the 793 songs, two trained coders analyzed independently the lyrics of each song for references to alcohol and alcohol brand appearances. Subsequent in-depth assessments utilized Atlas.ti to determine contextual factors associated with each of the alcohol brand appearances. Our final code book contained 27 relevant codes representing six categories: alcohol types, consequences, emotional states, activities, status and objects. Average inter-rater reliability was high (κ = 0.80), and all differences were easily adjudicated. Of the 793 songs in our sample, 169 (21.3%) referred explicitly to alcohol, and of those, 41 (24.3%) contained an alcohol brand appearance. Consequences associated with alcohol were more often positive than negative (41.5% versus 17.1%, P brand appearances were associated commonly with wealth (63.4%), sex (58.5%), luxury objects (51.2%), partying (48.8%), other drugs (43.9%) and vehicles (39.0%). One in five songs sampled from US popular music had explicit references to alcohol, and one-quarter of these mentioned a specific alcohol brand. These alcohol brand appearances are associated commonly with a luxury life-style characterized by wealth, sex, partying and other drugs. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

  9. Neutrino Oscillation Results from NOvA

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    NOvA is an accelerator long-baseline neutrino oscillation experiment optimised to measure electron neutrino appearance in a high-purity beam of muon neutrinos from Fermilab. The exciting discovery of the theta13 neutrino mixing angle in 2012 has opened a door to making multiple new measurements of neutrinos. These include leptonic CP violation, the neutrino mass ordering and the octant of theta23. NOvA with its 810km baseline and higher energy beam has about triple the matter effect of T2K which opens a new window on the neutrino mass ordering. With about 20% of our design beam exposure and significant analysis improvements we have recently released updated results. I will present both our disappearance and appearance measurements.

  10. Reflectance, illumination, and appearance in color constancy.

    Science.gov (United States)

    McCann, John J; Parraman, Carinna; Rizzi, Alessandro

    2014-01-01

    We studied color constancy using a pair of identical 3-D Color Mondrian displays. We viewed one 3-D Mondrian in nearly uniform illumination, and the other in directional, nonuniform illumination. We used the three dimensional structures to modulate the light falling on the painted surfaces. The 3-D structures in the displays were a matching set of wooden blocks. Across Mondrian displays, each corresponding facet had the same paint on its surface. We used only 6 chromatic, and 5 achromatic paints applied to 104 block facets. The 3-D blocks add shadows and multiple reflections not found in flat Mondrians. Both 3-D Mondrians were viewed simultaneously, side-by-side. We used two techniques to measure correlation of appearance with surface reflectance. First, observers made magnitude estimates of changes in the appearances of identical reflectances. Second, an author painted a watercolor of the 3-D Mondrians. The watercolor's reflectances quantified the changes in appearances. While constancy generalizations about illumination and reflectance hold for flat Mondrians, they do not for 3-D Mondrians. A constant paint does not exhibit perfect color constancy, but rather shows significant shifts in lightness, hue and chroma in response to the structure in the nonuniform illumination. Color appearance depends on the spatial information in both the illumination and the reflectances of objects. The spatial information of the quanta catch from the array of retinal receptors generates sensations that have variable correlation with surface reflectance. Models of appearance in humans need to calculate the departures from perfect constancy measured here. This article provides a dataset of measurements of color appearances for computational models of sensation.

  11. Reflectance, illumination, and appearance in color constancy

    Directory of Open Access Journals (Sweden)

    John J. McCann

    2014-01-01

    Full Text Available We studied color constancy using a pair of identical 3-D Color Mondrian displays. We viewed one 3-D Mondrian in nearly uniform illumination, and the other in directional, nonuniform illumination. We used the three dimensional structures to modulate the light falling on the painted surfaces. The 3-D structures in the displays were a matching set of wooden blocks. Across Mondrian displays, each corresponding facet had the same paint on its surface. We used only 6 chromatic, and 5 achromatic paints applied to 104 block facets. The 3-D blocks add shadows and multiple reflections not found in flat Mondrians. Both 3-D Mondrians were viewed simultaneously, side-by-side. We used two techniques to measure correlation of appearance with surface reflectance. First, observers made magnitude estimates of changes in the appearances of identical reflectances. Second, an author painted a watercolor of the 3-D Mondrians. The watercolor’s reflectances quantified the changes in appearances. While constancy generalizations about illumination and reflectance hold for flat Mondrians, they do not for 3-D Mondrians. A constant paint does not exhibit perfect color constancy, but rather shows significant shifts in lightness, hue and chroma in response to the structure in the nonuniform illumination. Color appearance depends on the spatial information in both the illumination and the reflectances of objects. The spatial information of the quanta catch from the array of retinal receptors generates sensations that have variable correlation with surface reflectance. Models of appearance in humans need to calculate the departures from perfect constancy measured here. This article provides a dataset of measurements of color appearances for computational models of sensation.

  12. A theory of generalized Bloch oscillations

    International Nuclear Information System (INIS)

    Duggen, Lars; Lassen, Benny; Lew Yan Voon, L C; Willatzen, Morten

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact calculation is given to confirm this phenomenon. Our results allow for a greater freedom of design for experimentally observing Bloch oscillations. For strongly coupled oscillator systems displaying Bloch oscillations, it is further demonstrated that reordering of oscillators leads to destruction of Bloch oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics. (paper)

  13. Radiological appearances of degenerative uterine leiomyomas

    International Nuclear Information System (INIS)

    Tzvetankov, K.; Hadjidekov, G.; Plachkov, I.; Yankova, M.

    2013-01-01

    Uterine fibroids, also known as leiomyomas, are the most common uterine neoplasms. Although benign, they can be associated with significant morbidity and are the commonest indication for hysterectomy. They are often discovered incidentally when performing imaging for other reasons. Usually first identified with US, they can be further characterized with MRI. They are usually easily recognizable, but degenerate fibroids can have unusual appearances. Knowledge of the different appearances of fibroids on imaging is important as it enables prompt diagnosis and thereby guides treatment. (authors)

  14. Auto-oscillations of temperature and defect density in impure crystals under irradiation

    International Nuclear Information System (INIS)

    Selishchev, P.A.; Sugakov, V.I.

    1990-01-01

    Appearance of auto-oscillations in temperature and defect density of impurity crystals under irradiation is studied. It is shown that at certain critical parameters stationary distribution of temperature and defect density of the sample irradiated becomes unstable as regards the formation of temporal dissipative structures: auto-oscillations of temperature and defect density. Critical parameters are determined (the rate of defect formation, temperature of crystal environment, etc.) and the frequency of appearing auto-oscillations, its dependence on irradiation conditions and crystal properties are found

  15. Breathing multichimera states in nonlocally coupled phase oscillators

    Science.gov (United States)

    Suda, Yusuke; Okuda, Koji

    2018-04-01

    Chimera states for the one-dimensional array of nonlocally coupled phase oscillators in the continuum limit are assumed to be stationary states in most studies, but a few studies report the existence of breathing chimera states. We focus on multichimera states with two coherent and incoherent regions and numerically demonstrate that breathing multichimera states, whose global order parameter oscillates temporally, can appear. Moreover, we show that the system exhibits a Hopf bifurcation from a stationary multichimera to a breathing one by the linear stability analysis for the stationary multichimera.

  16. Addendum to "Compact Perturbative Expressions for Neutrino Oscillations in Matter"

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Peter B. [Bohr Inst.; Minakata, Hisakazu [CSIC, Madrid; Parke, Stephen J. [Fermilab

    2018-01-19

    In this paper we rewrite the neutrino mixing angles and mass squared differences in matter given, in our original paper, in a notation that is more conventional for the reader. Replacing the usual neutrino mixing angles and mass squared differences in the expressions for the vacuum oscillation probabilities with these matter mixing angles and mass squared differences gives an excellent approximation to the oscillation probabilities in matter. Comparisons for T2K, NOvA, T2HKK and DUNE are also given for neutrinos and anti-neutrinos, disappearance and appearance channels, normal ordering and inverted ordering.

  17. Neutrino oscillation: status and outlooks

    International Nuclear Information System (INIS)

    Nedelec, P.

    1994-01-01

    Whether the neutrinos are massive or not is one of the most puzzling question of physics today. If they are massive, they can contribute significantly to the Dark Matter of the Universe. An other consequence of a non-zero mass of neutrinos is that they might oscillate from one flavor to another. This oscillation process is by now the only way to detect a neutrino with a mass in the few eV range. Several neutrino experiments are currently looking for such an oscillation, in different modes, using different techniques. An overview of the experimental situation for neutrino experiments at accelerators is given. (author). 9 refs., 5 figs., 5 tabs

  18. Synchronous Oscillations in Microtubule Polymerization

    Science.gov (United States)

    Carlier, M. F.; Melki, R.; Pantaloni, D.; Hill, T. L.; Chen, Y.

    1987-08-01

    Under conditions where microtubule nucleation and growth are fast (i.e., high magnesium ion and tubulin concentrations and absence of glycerol), microtubule assembly in vitro exhibits an oscillatory regime preceding the establishment of steady state. The amplitude of the oscillations can represent >50% of the maximum turbidity change and oscillations persist for up to 20 periods of 80 s each. Oscillations are accompanied by extensive length redistribution of microtubules. Preliminary work suggests that the oscillatory kinetics can be simulated using a model in which many microtubules undergo synchronous transitions between growing and rapidly depolymerizing phases, complicated by the kinetically limiting rate of nucleotide exchange on free tubulin.

  19. Rabi oscillation between states of a coupled harmonic oscillator

    International Nuclear Information System (INIS)

    Park, Tae Jun

    2003-01-01

    Rabi oscillation between bound states of a single potential is well known. However the corresponding formula between the states of two different potentials has not been obtained yet. In this work, we derive Rabi formula between the states of a coupled harmonic oscillator which may be used as a simple model for the electron transfer. The expression is similar to typical Rabi formula for a single potential. This result may be used to describe transitions between coupled diabatic potential curves

  20. Oscillations in Mathematical Biology

    CERN Document Server

    1983-01-01

    The papers in this volume are based on talks given at a one day conference held on the campus of Adelphi University in April 1982. The conference was organized with the title "Oscillations in Mathematical Biology;" however the speakers were allowed considerable latitutde in their choice of topics. In the event, the talks all concerned the dynamics of non-linear systems arising in biology so that the conference achieved a good measure of cohesion. Some of the speakers cho~e not to submit a manuscript for these proceedings, feeling that their material was too conjectural to be committed to print. Also the paper of Rinzel and Troy is a distillation of the two separate talks that the authors gave. Otherwise the material reproduces the conference proceedings. The conference was made possible by the generous support of the Office of the Dean of the College of Arts and Sciences at Adelphi. The bulk of the organization of the conference was carried out by Dr. Ronald Grisell whose energy was in large measure responsib...

  1. What Genes Tell about Iris Appearance

    DEFF Research Database (Denmark)

    Harder, Stine; Christoffersen, Susanne R.; Johansen, Peter

    2012-01-01

    Predicting phenotypes based on genotypes is generally hard, but has shown good results for prediction of iris color. We propose to correlate the appearance of iris with DNA. Six single-nucleotide polymorphisms (SNPs) have previously been shown to correlate with human iris color, and we demonstrat...

  2. 'Unusual' MRI appearance of sphenoid sinus mucocele

    International Nuclear Information System (INIS)

    Ruelle, A.; Pisani, R.; Andrioli, G.

    1991-01-01

    The authors report a case of sphenoid sinus mucocele which exhibited unusual MRI features. However a review of the literature shows that these lesions may present with different MRI appearances probably related to the variability of the cyst content. Further series are needed for a better definition of the MRI behaviour of the lesions. (orig.)

  3. 39 CFR 3001.6 - Appearances.

    Science.gov (United States)

    2010-07-01

    ... Commission online as a Principal Account Holder, or signs a paper filed with the Commission, his/her personal appearance, online submission, or signature, shall constitute a representation to the Commission that he/she..., 1971, as amended at 38 FR 4327, Feb. 13, 1973; 51 FR 8827, Mar. 14, 1986; 58 FR 38976, July 21, 1993...

  4. 40 CFR 305.10 - Appearances.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION, AND LIABILITY ACT... appear as counsel or other representative must conform to the standards of conduct and ethics required of...

  5. Object tracking using active appearance models

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille

    2001-01-01

    This paper demonstrates that (near) real-time object tracking can be accomplished by the deformable template model; the Active Appearance Model (AAM) using only low-cost consumer electronics such as a PC and a web-camera. Successful object tracking of perspective, rotational and translational...

  6. 40 CFR 22.10 - Appearances.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Appearances. 22.10 Section 22.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL CONSOLIDATED RULES OF PRACTICE GOVERNING... and ethics required of practitioners before the courts of the United States. ...

  7. Protean appearance of craniopharyngioma on computed tomography

    International Nuclear Information System (INIS)

    Danziger, A.; Price, H.I.

    1979-01-01

    Craniopharyngiomas present a diverse appearance on computed tomography. Histological diagnosis is not always possible, but computed tomography is of great assistance in the delineation of the tumour as well as of the degree of associated hydrocephalus. Computed tomography also enables rapid non-invasive follow-up after surgery or radiotherapy, or both

  8. Physical Appearance and Student/Teacher Interactions

    Science.gov (United States)

    Perlmutter, David L.

    2005-01-01

    Scientific and cultural research suggests that attractiveness does affect the ways that people perceive and respond to each other. In this paper, the author talks about the impact of one's appearance in academe as well as in the relationship between students and professors. From the research literature, popular writings, and many comments from his…

  9. Ultrasound appearances of Implanon implanted contraceptive devices.

    LENUS (Irish Health Repository)

    McNeill, G

    2009-09-01

    Subdermal contraceptive devices represent a popular choice of contraception. Whilst often removed without the use of imaging, circumstances exist where imaging is required. Ultrasound is the modality of choice. The optimal technique and typical sonographic appearances are detailed in this article.

  10. Radiological appearances of papillary breast lesions

    International Nuclear Information System (INIS)

    Brookes, M.J.; Bourke, A.G.

    2008-01-01

    This review illustrates the varied appearances of benign and malignant papillary breast tumours, as identified by a breast cancer-screening programme. The commonest mammographic appearance of a papillary tumour is as a soft-tissue mass, with calcification present in less than half of cases. When calcification is present the pattern is variable, but clusters of pleomorphic calcification can occur, sometimes resembling the mammographic appearance of invasive ductal carcinoma. Ultrasonography of papillary lesions typically shows a solid, oval, intraductal mass, often associated with duct dilatation. A cystic component is also commonly seen, and lesions may appear hypervascular on colour Doppler ultrasound. Magnetic resonance imaging (MRI) has a high sensitivity, but low specificity for detecting papillary tumours, and is useful in establishing the extent and distribution of lesions in patients with multiple papillomatosis. Despite a benign histology on core biopsy, an argument exists for complete surgical excision of all papillary tumours, as a significant proportion of papillomas will contain foci of atypia or overt malignant change

  11. Radiological appearances of papillary breast lesions

    Energy Technology Data Exchange (ETDEWEB)

    Brookes, M.J. [Sir Charles Gairdner Hospital, Nedlands, Perth, Western Australia (Australia)], E-mail: mattbrookes@doctors.org.uk; Bourke, A.G. [Sir Charles Gairdner Hospital, Nedlands, Perth, Western Australia (Australia)

    2008-11-15

    This review illustrates the varied appearances of benign and malignant papillary breast tumours, as identified by a breast cancer-screening programme. The commonest mammographic appearance of a papillary tumour is as a soft-tissue mass, with calcification present in less than half of cases. When calcification is present the pattern is variable, but clusters of pleomorphic calcification can occur, sometimes resembling the mammographic appearance of invasive ductal carcinoma. Ultrasonography of papillary lesions typically shows a solid, oval, intraductal mass, often associated with duct dilatation. A cystic component is also commonly seen, and lesions may appear hypervascular on colour Doppler ultrasound. Magnetic resonance imaging (MRI) has a high sensitivity, but low specificity for detecting papillary tumours, and is useful in establishing the extent and distribution of lesions in patients with multiple papillomatosis. Despite a benign histology on core biopsy, an argument exists for complete surgical excision of all papillary tumours, as a significant proportion of papillomas will contain foci of atypia or overt malignant change.

  12. Nodular fasciitis: MRI appearance and literature review

    International Nuclear Information System (INIS)

    Leung, L.Y.J.; Shu, S.J.; Chan, M.K.; Chan, C.H.S.; Chan, A.C.L.

    2002-01-01

    Objective: To describe the MRI features of nodular fasciitis and to review the clinical, MRI and histologic aspects of the tumor. Design and patients: Three patients with biopsy-proven nodular fasciitis were selected for a retrospective study. A literature review was also carried out. Results and conclusions: All the lesions appeared slightly hyperintense to skeletal muscle on T1-weighted images, and hyperintense on T2-weighted images with fat saturation [either frequency saturation or Short TI Inversion Recovery (STIR) sequences]. Two enhanced homogeneously after intravenous gadolinium, whereas the third showed heterogeneous enhancement with a nonenhancing area. Despite the difference in enhancing patterns, the histologic appearances of these lesions were similar. Our study shows that the MRI appearance of nodular fasciitis may not be related to the location of lesion. It is thought that the age of nodular fasciitis may reflect its gross morphology, and it is possible that the MRI and histologic appearances could correlate with the age of the lesion, but it would require a larger series to evaluate this concept. (orig.)

  13. Effect of non-condensation gas on pressure oscillation of submerged steam jet condensation

    International Nuclear Information System (INIS)

    Zhao, Quanbin; Cong, Yuelei; Wang, Yingchun; Chen, Weixiong; Chong, Daotong; Yan, Junjie

    2016-01-01

    Highlights: • Oscillation intensity of steam–air jet increases with rise of water temperature. • Oscillation intensity reduces obviously when air is mixed. • Both first and second dominant frequencies decrease with rise of air mass fraction. • Air has little effect on power of 1st & 2nd frequency bands under low temperature. • The maximum oscillation power occurs under case of A = 1% and T ⩾ 50 °C. - Abstract: The effect of air with low mass fraction on the oscillation intensity and oscillation frequency of a submerged steam jet condensation is investigated under stable condensation region. With air mixing in steam, an obvious dynamic pressure peak appears along the jet direction. The intensity peak increases monotonously with the rise of steam mass flux and water temperature. Peak position moves downstream with the rise of air mass fraction. Moreover, when compared with that of pure steam jet, the oscillation intensity clearly decreases as air is mixed. However, when water temperature is lower than approximately 45 °C, oscillation intensity increases slightly with the rise of air mass fraction, and when water temperature is higher than 55 °C, the oscillation intensity decreases greatly with the rise of air mass fraction. Both the first and second dominant frequencies decrease with rise of air mass fraction. Finally, effect of air mass fractions on the oscillation power of the first and second dominant frequency bands shows similar trends. Under low water temperature, the mixed air has little effect on the oscillation power of both first and second frequency bands. However, when water temperature is high, the oscillation power of both first and second frequency bands appears an obvious peak when air mass fraction is about 1%. With further rise of air mass fraction, the oscillation power decreases gradually.

  14. The Duffing oscillator with damping

    DEFF Research Database (Denmark)

    Johannessen, Kim

    2015-01-01

    An analytical solution to the differential equation describing the Duffing oscillator with damping is presented. The damping term of the differential equation and the initial conditions satisfy an algebraic equation, and thus the solution is specific for this type of damping. The nonlinear term...... of the differential equation is allowed to be considerable compared to the linear term. The solution is expressed in terms of the Jacobi elliptic functions by including a parameter-dependent elliptic modulus. The analytical solution is compared to the numerical solution, and the agreement is found to be very good....... It is established that the period of oscillation is shorter compared to that of a linearized model but increasing with time and asymptotically approaching the period of oscillation of the linear damped model. An explicit expression for the period of oscillation has been derived, and it is found to be very accurate....

  15. Thermoelastic Loss in Microscale Oscillators

    National Research Council Canada - National Science Library

    Houston, B. H; Photiadis, D. M; Marcus, M. H; Bucaro, J. A; Liu, Xiao; Vignola, J. F

    2001-01-01

    ...) and nanoelectromechanical (NEMS) oscillators. The theory defines a flexural modal participation factor, the fraction of potential energy stored in flexure, and approximates the internal friction by assuming the energy loss to occur solely via...

  16. Oscillating nonlinear acoustic shock waves

    DEFF Research Database (Denmark)

    Gaididei, Yuri; Rasmussen, Anders Rønne; Christiansen, Peter Leth

    2016-01-01

    We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show that at resona......We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show...... polynomial in the space and time variables, we find analytical approximations to the observed single shock waves in an infinitely long tube. Using perturbation theory for the driven acoustic system approximative analytical solutions for the off resonant case are determined....

  17. Transient voltage oscillations in coils

    International Nuclear Information System (INIS)

    Chowdhuri, P.

    1985-01-01

    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

  18. Modelling solar-like oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Eggenberger, P; Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, 17 Allee du 6 Aout, B-4000 Liege (Belgium); Carrier, F [Institute of Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Mathis, S [CEA/DSM/DAPNIA/Service d' Astrophysique, CEA/Saclay, AIM-Unite Mixte de Recherche CEA-CNRS-Universite Paris VII, UMR 7158, 91191 Gif-sur-Yvette Cedex (France)], E-mail: eggenberger@Qastro.ulg.ac.be

    2008-10-15

    The computation of models of stars for which solar-like oscillations have been observed is discussed. After a brief intoduction on the observations of solar-like oscillations, the modelling of isolated stars and of stars belonging to a binary system is presented with specific examples of recent theoretical calibrations. Finally the input physics introduced in stellar evolution codes for the computation of solar-type stars is discussed with a peculiar emphasis on the modelling of rotation for these stars.

  19. Endometrial ablation: normal appearance and complications.

    Science.gov (United States)

    Drylewicz, Monica R; Robinson, Kathryn; Siegel, Cary Lynn

    2018-03-14

    Global endometrial ablation is a commonly performed, minimally invasive technique aimed at improving/resolving abnormal uterine bleeding and menorrhagia in women. As non-resectoscopic techniques have come into existence, endometrial ablation performance continues to increase due to accessibility and decreased requirements for operating room time and advanced technical training. The increased utilization of this method translates into increased imaging of patients who have undergone the procedure. An understanding of the expected imaging appearances of endometrial ablation using different modalities is important for the abdominal radiologist. In addition, the frequent usage of the technique naturally comes with complications requiring appropriate imaging work-up. We review the expected appearance of the post-endometrial ablated uterus on multiple imaging modalities and demonstrate the more common and rare complications seen in the immediate post-procedural time period and remotely.

  20. CT appearance and features of tubal pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Xiaohong, Wang; Hong, Shan; Zaibo, Jiang; Xinghe, Deng; Xiaochun, Meng; Bingbing, Ye; Mingyue, Luo; Yunya, Lin [Sun Yat-sen Univ., Guangzhou (China). The Third Univ. Hospital, Dept. of Radiology

    2004-06-01

    Objective: To investigate the CT appearance and features of tubal pregnancy. Methods: Precontrast and postcontrast CT scans were employed in 38 patients who were clinically and ultrasonographically suspected of tubal pregnancy. 34 of them were verified as tubal pregnancy through operative pathology. Results: 1. The direct CT imaging feature was the whole pregnancies sac (4/34, 11.8%) or half-baked pregnancies sac (14/34, 41.2%); 2. The indirect CT imaging features were: (1) abnormal density image, which could be enhanced, in a cystic mass around adnexal area (8/34, 23.5%); (2) mix density mass around adnexal area, which was mainly solid and had mild to moderate inhomogeneous enhancement (19/34, 55.9%); (3) large area irregular shadow with high density were found beside the uterus, with no enhancement (3/34, 8.8%). (4) bloody density in uterus-rectum-fossa (23/34, 67.6%). 3. The CT imaging features of tubal pregnancy was classified as: (1) Pregnant sac type (4/34, 11.8%); (2) Cystic (8/34, 23.5%); (3) Massive type (17/34, 50%); (4) Chronic mass type (2/34, 5.9%); (5) Bleeding type (3/34, 8.8%). 4. The CT imaging appearance of tubal pregnancy related with the pregnancy location; 5. The CT imaging appearance of tubal pregnancy related with the clinical significant. Conclusion: The CT imaging appearance of tubal pregnancy has some features, which can help in the diagnosis or differential diagnosis of the pelvis masses. CT scan is an effective supplementary attempt to the clinically and ultrasonographically suspected tubal pregnancy patients.

  1. Scintigraphic appearance of the piriformis muscle syndrome

    International Nuclear Information System (INIS)

    Karl, R.D. Jr.; Yedinak, M.A.; Hartshorne, M.F.; Cawthon, M.A.; Bauman, J.M.; Howard, W.H.; Bunker, S.R.

    1985-01-01

    This is the first report in the nuclear medicine literature of the scintigraphic appearance of the piriformis muscle syndrome. This syndrome previously has been thought to be a purely clinical diagnosis and imaging modalities have been ignored. However, its confusing clinical presentation can lead to unnecessary surgical exploration. This case is presented to illustrate the characteristic scintigraphic pattern and suggest the role of nuclear medicine scanning in establishing the diagnosis

  2. CT appearance and features of tubal pregnancy

    International Nuclear Information System (INIS)

    Wang Xiaohong; Shan Hong; Jiang Zaibo; Deng Xinghe; Meng Xiaochun; Ye Bingbing; Luo Mingyue; Lin Yunya

    2004-01-01

    Objective: To investigate the CT appearance and features of tubal pregnancy. Methods: Precontrast and postcontrast CT scans were employed in 38 patients who were clinically and ultrasonographically suspected of tubal pregnancy. 34 of them were verified as tubal pregnancy through operative pathology. Results: 1. The direct CT imaging feature was the whole pregnancies sac (4/34, 11.8%) or half-baked pregnancies sac (14/34, 41.2%); 2. The indirect CT imaging features were: (1) abnormal density image, which could be enhanced, in a cystic mass around adnexal area (8/34, 23.5%); (2) mix density mass around adnexal area, which was mainly solid and had mild to moderate inhomogeneous enhancement (19/34, 55.9%); (3) large area irregular shadow with high density were found beside the uterus, with no enhancement (3/34, 8.8%). (4) bloody density in uterus-rectum-fossa (23/34, 67.6%). 3. The CT imaging features of tubal pregnancy was classified as: (1) Pregnant sac type (4/34, 11.8%); (2) Cystic (8/34, 23.5%); (3) Massive type (17/34, 50%); (4) Chronic mass type (2/34, 5.9%); (5) Bleeding type (3/34, 8.8%). 4. The CT imaging appearance of tubal pregnancy related with the pregnancy location; 5. The CT imaging appearance of tubal pregnancy related with the clinical significant. Conclusion: The CT imaging appearance of tubal pregnancy has some features, which can help in the diagnosis or differential diagnosis of the pelvis masses. CT scan is an effective supplementary attempt to the clinically and ultrasonographically suspected tubal pregnancy patients

  3. Owl's eye appearance: a case report

    International Nuclear Information System (INIS)

    Mathur, Mukul; Asha, P.

    2010-01-01

    Full text: Hyper-functioning thyroid nodule may present various scintigraphic appearances on thyroid scans. Autonomously hyper functioning thyroid nodules often show degenerative changes. These changes may give rise to peripheral photopenic areas on a thyroid scan. In this report we present a case of hyper functioning nodule showing appearance of an owl's eye. Although rare, such pattern can be seen in a variety of benign and malignant thyroid conditions. A 42-year-old man presented with a solitary thyroid nodule in the right lobe and weight loss for four months. The thyroid hormone profile confirmed hyperthyroidism. Thyroid function testing revealed T4=136.8 nmol/l (Normal = 66.0-181.0 nmol/L) and Thyroid Stimulating Hormone (TSH) = 0.283 (Normal =0.27- 4.2 μIU/ml). Antithyroglobulin antibodies and antimicrosmal antibodies were negative. The patient was referred for thyroid scan and uptake. A Thyroid scan was obtained after the intravenous injection of 5 mCi (185MBq) of 99m Tc pertechnetate. Anterior view obtained using a parallel hole collimator. The scan showed peripheral photopenic area with a central focal area of increased uptake giving the appearance of 'Owl's eye'. 99m Tc-pertechnetate uptake was increased. A scintigraphic 'Owl's eye' sign has been described in thyroid cyst, benign autonomous nodule and papillary carcinoma of the thyroid gland. This Owl's eye pattern appears to be caused by a focus of functioning tissue overlapping a large cold area in a nodule that has cystic,degenerative and necrotic changes in the middle of a benign and malignant pathology. Hyper functioning nodules may scintigraphically show Owl's eye pattern due to intra nodular degeneration, with residual hyper functioning tissue within or overlapping the degenerative area

  4. Modeling nonlinearities in MEMS oscillators.

    Science.gov (United States)

    Agrawal, Deepak K; Woodhouse, Jim; Seshia, Ashwin A

    2013-08-01

    We present a mathematical model of a microelectromechanical system (MEMS) oscillator that integrates the nonlinearities of the MEMS resonator and the oscillator circuitry in a single numerical modeling environment. This is achieved by transforming the conventional nonlinear mechanical model into the electrical domain while simultaneously considering the prominent nonlinearities of the resonator. The proposed nonlinear electrical model is validated by comparing the simulated amplitude-frequency response with measurements on an open-loop electrically addressed flexural silicon MEMS resonator driven to large motional amplitudes. Next, the essential nonlinearities in the oscillator circuit are investigated and a mathematical model of a MEMS oscillator is proposed that integrates the nonlinearities of the resonator. The concept is illustrated for MEMS transimpedance-amplifier- based square-wave and sine-wave oscillators. Closed-form expressions of steady-state output power and output frequency are derived for both oscillator models and compared with experimental and simulation results, with a good match in the predicted trends in all three cases.

  5. Fundamental and Harmonic Oscillations in Neighboring Coronal Loops

    Science.gov (United States)

    Li, Hongbo; Liu, Yu; Vai Tam, Kuan

    2017-06-01

    We present observations of multimode (fundamental and harmonic) oscillations in a loop system, which appear to be simultaneously excited by a GOES C-class flare. Analysis of the periodic oscillations reveals that (1) the primary loop with a period of P a ≈ 4 minutes and a secondary loop with two periods of P a ≈ 4 minutes and P b ≈ 2 minutes are detected simultaneously in closely spaced loop strands; (2) both oscillation components have their peak amplitudes near the loop apex, while in the second loop the low-frequency component P a dominates in a loop segment that is two times larger than the high-frequency component P b ; (3) the harmonic mode P b shows the largest deviation from a sinusoidal loop shape at the loop apex. We conclude that multiple harmonic modes with different displacement profiles can be excited simultaneously even in closely spaced strands, similar to the overtones of a violin string.

  6. Energy localization in the phi4 oscillator chain.

    Science.gov (United States)

    Ponno, A; Ruggiero, J; Drigo, E; De Luca, J

    2006-05-01

    We study energy localization in a finite one-dimensional phi(4) oscillator chain with initial energy in a single oscillator of the chain. We numerically calculate the effective number of degrees of freedom sharing the energy on the lattice as a function of time. We find that for energies smaller than a critical value, energy equipartition among the oscillators is reached in a relatively short time. On the other hand, above the critical energy, a decreasing number of particles sharing the energy is observed. We give an estimate of the effective number of degrees of freedom as a function of the energy. Our results suggest that localization is due to the appearance, above threshold, of a breather-like structure. Analytic arguments are given, based on the averaging theory and the analysis of a discrete nonlinear Schrödinger equation approximating the dynamics, to support and explain the numerical results.

  7. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  8. Some comparison of two fractional oscillators

    International Nuclear Information System (INIS)

    Kang Yonggang; Zhang Xiu'e

    2010-01-01

    The other form of fractional oscillator equation comparing to the widely discussed one is ushered in. The properties of vibration of two fractional oscillators are discussed under the influence of different initial conditions. The interpretation of the characteristics of the fractional oscillators using different method is illustrated. Based on two fractional oscillator equations, two linked bodies and the continuous system are studied.

  9. Magnetically Coupled Magnet-Spring Oscillators

    Science.gov (United States)

    Donoso, G.; Ladera, C. L.; Martin, P.

    2010-01-01

    A system of two magnets hung from two vertical springs and oscillating in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled oscillators. The electromagnetically coupled oscillations of these oscillators are experimentally and theoretically studied. Its coupling is electromagnetic instead of…

  10. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.; Salama, Khaled N.

    2009-01-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  11. On the mechanism of oscillations in neutrophils

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Barington, Torben; Olsen, Lars Folke

    2010-01-01

    We have investigated the regulation of the oscillatory generation of H(2)O(2) and oscillations in shape and size in neutrophils in suspension. The oscillations are independent of cell density and hence do not represent a collective phenomena. Furthermore, the oscillations are independent...... of the external glucose concentration and the oscillations in H(2)O(2) production are 180 degrees out of phase with the oscillations in NAD(P)H. Cytochalasin B blocked the oscillations in shape and size whereas it increased the period of the oscillations in H(2)O(2) production. 1- and 2-butanol also blocked...... the oscillations in shape and size, but only 1-butanol inhibited the oscillations in H(2)O(2) production. We conjecture that the oscillations are likely to be due to feedback regulations in the signal transduction cascade involving phosphoinositide 3-kinases (PI3K). We have tested this using a simple mathematical...

  12. Reactor oscillator - I - III, Part I; Reaktorski oscilator - I-III, I Deo

    Energy Technology Data Exchange (ETDEWEB)

    Lolic, B [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Project 'Reactor oscillator' covers the following activities: designing reactor oscillators for reactors RA and RB with detailed engineering drawings; constructing and mounting of the oscillator; designing and constructing the appropriate electronic equipment for the oscillator; measurements at the RA and RB reactors needed for completing the oscillator construction.

  13. Ultrasound appearance of chronic mammary duct ectasia

    Energy Technology Data Exchange (ETDEWEB)

    Duchesne, N. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)]. E-mail: nathalie_duchesne_22@yahoo.ca; Skolnik, S. [Univ. of Toronto, Dept. of Family Medicine, Toronto, Ontario (Canada); Bilmer, S. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)

    2005-12-15

    Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

  14. Ultrasound appearance of chronic mammary duct ectasia

    International Nuclear Information System (INIS)

    Duchesne, N.; Skolnik, S.; Bilmer, S.

    2005-01-01

    Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

  15. Comparison of hydrocephalus appearance at spinaldysraphia.

    Science.gov (United States)

    Elshani, Besnik; Lenjani, Basri

    2013-01-01

    Congenital malformation of spinal dysraphism followed by hydrocephalus are phenomenon reveals during intrauterine child growth. Prime objective of this work was to present Comparison of hydrocephalus appearance at spinal dysraphism respectively at its meningocele and myelomeningocele forms in Neurosurgery Clinic in UCC in Prishtina. It is perfected with retrospective and prospective method precisely of its epidemiologic part summarizing notices from patients' histories which in 2000-2006 are hospitalized in Neurosurgery Clinic from (QFLPK)--Pediatric Clinic and Children Box (Department)--Gynecology Clinic and from Sanitary Regional Center throughout Kosova. Our study objects were two groups, as the first group 90 patients with spinal dysraphism where neurosurgery operations were done and classified types of dysraphism. At myelomeningocele hydrocephalus has dominated and in a percent of appearance and as acute of its active form was 97% of hydrocephalus form where subjected to cerebrospinal liquid derivation with ventriculo -peritoneal shunt in comparison with meningocele we do not have involvation of spinal nerve element, hydrocephalus takes active form with intervention indication in 60% of cases. Reflection in shown deficit aspect is totally different at myelomeningoceles where lower paraplegia dominate more than paraparesis. The second patient operative technique developed by hydrocephalus with neurosurgical intervention indication has to do with placing of (VP) ventriculo- peritoneal system (shant) at myelomeningoceles with hydrocephalus 58 cases and 12 cases meningoceles with hydrocephalus. Post operative meningitis (shant meningitis): from 70 operated cases of hydrocephalus with spinal dysraphism shunts complications from all types are just cases. Finally that appearance of hydrocephalus compared at spinal dysraphism dominate at myellomeningoceles as in notice time aspect, it is persisting and further acute, with vital motivation for neurosurgical

  16. Postoperative CT appearance in chronic subdural hematomas

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Takaaki; Nishikawa, Michio; Handa, Hajime; Iwaki, Kazuo; Sawai, Teruaki; Munaka, Masahiro

    1988-05-01

    Postoperative CT appearances in 65 cases of chronic subdural hematomas were evaluated in terms of patient's age, preoperative neurological symptoms and CT findings, final outcomes, and so on. All of the cases were treated with trepanation and irrigation. CT appearances were divided into four different types as follows; Type Ia: No abnormal findings in the subdural sapce, Type Ib: The same as above except for a linear high density suggestive of thickened outer membrane, Type II: Persistence subdural fluid collection and widened cortical sulci which indicate underlining brain atrophy, Type III: Remaining hematoma and/or density changes during follow-up period. Although the mean age of the patients in type Ib was higher than those in type Ia and reexpansion of the brain appear to delay in type Ib and preoperative CT in type Ib tended to show mixed density, final outcome in both groups were excellent. Characteristics in type II were that most of cases were in the eighth decade, preceding head injury was unclear, preoperative psychiatric symptoms and disturbance of consciousness were common and postoperative improvement of the symptoms was not satisfactory compared to other types. Aged patients as in type Ib and type II and thick hematomas of over 2 cm depth with mixed or high density tended to show type III postoperatively. All of the nine patients who required reoperation were included in this type. The present study indicates that thick hematomas with sizable mass effect and mixed or high density in the aged must be carefully treated, such as with placement of the subdural drainage or keeping the patient in the Trendelenburg position, to facilitate postoperative reexpansion of the brain.

  17. Appearance of Keplerian discs orbiting Kerr superspinars

    Energy Technology Data Exchange (ETDEWEB)

    Stuchlik, Zdenek; Schee, Jan, E-mail: zdenek.stuchlik@fpf.slu.c, E-mail: jan.schee@fpf.slu.c [Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezrucovo nam. 13, Opava (Czech Republic)

    2010-11-07

    We study optical phenomena related to the appearance of Keplerian accretion discs orbiting Kerr superspinars predicted by string theory. The superspinar exterior is described by standard Kerr naked singularity geometry breaking the black hole limit on the internal angular momentum (spin). We construct local photon escape cones for a variety of orbiting sources that enable us to determine the superspinars silhouette in the case of distant observers. We show that the superspinar silhouette depends strongly on the assumed edge where the external Kerr spacetime is joined to the internal spacetime governed by string theory and significantly differs from the black hole silhouette. The appearance of the accretion disc is strongly dependent on the value of the superspinar spin in both their shape and frequency shift profile. Apparent extension of the disc grows significantly with the growing spin, while the frequency shift grows with the descending spin. This behaviour differs substantially from the appearance of discs orbiting black holes enabling thus, at least in principle, to distinguish clearly the Kerr superspinars and black holes. In vicinity of a Kerr superspinar the non-escaped photons have to be separated to those captured by the superspinar and those being trapped in its strong gravitational field leading to self-illumination of the disc that could even influence its structure and cause self-reflection effect of radiation of the disc. The amount of trapped photons grows with descending superspinar spin. We thus can expect significant self-illumination effects in the field of Kerr superspinars with near-extreme spin a {approx} 1.

  18. MRI appearances of borderline ovarian tumours

    Energy Technology Data Exchange (ETDEWEB)

    Bent, C.L. [Department of Diagnostic Imaging, St Bartholomew' s Hospital, West Smithfield, London (United Kingdom)], E-mail: clare.bent@bartsandthelondon.nhs.uk; Sahdev, A.; Rockall, A.G. [Department of Diagnostic Imaging, St Bartholomew' s Hospital, West Smithfield, London (United Kingdom); Singh, N. [Department of Pathology, St Bartholomew' s Hospital, West Smithfield, London (United Kingdom); Sohaib, S.A. [Department of Radiology, Royal Marsden Hospital, London (United Kingdom); Reznek, R.H. [Cancer Imaging, St Bartholomew' s Hospital, West Smithfield, London (United Kingdom)

    2009-04-15

    This review was performed to describe the range of magnetic resonance imaging (MRI) appearances of borderline ovarian tumours. The MRI findings in 26 patients with 31 borderline ovarian tumours (mean age: 40.1 years, range: 14-85 years) were retrospectively reviewed. For each tumour, site, size, MRI characteristics, and enhancement following gadolinium administration were recorded. There were 20 serous and 11 mucinous borderline ovarian subtypes. Nine of 26 patients demonstrated bilateral disease on MRI; synchronous contralateral ovarian disease included three benign, five serous borderline, and one serous invasive tumour. A history of a metachronous mucinous borderline tumour was identified in one patient. MRI appearances were classified into four morphological categories: group 1 (6/31, 19%), unilocular cysts; group 2 (6/31, 19%), minimally septate cysts with papillary projections; group 3 (14/31, 45%), markedly septate lesions with plaque-like excrescences; and group 4 (5/31, 16%), predominantly solid with exophytic papillary projections, all of serous subtype. There was a significant difference in mean volume between serous (841.5 cm{sup 3}) and mucinous (6358.2 cm{sup 3}) subtypes (p = 0.009). All tumours demonstrated at least one MRI feature suggestive of malignancy. The present review demonstrates the variable MRI appearances of borderline ovarian tumours along with imaging features suggestive of tumour subtype. In patients in whom the clinical features are suggestive of a borderline ovarian tumour (young age and normal or minimally elevated CA125), the ability to predict a borderline disease using morphological features observed on MRI would be extremely helpful in surgical planning, with the potential to offer fertility or ovary-preserving surgery. Future studies are required to further this aim.

  19. Appearance and methods of prostatic arteriography

    International Nuclear Information System (INIS)

    Chang Gang; Yang Zhigang; Meng Fanzhe; Zhang Yingguang; Chen Zhiqiang; Yang Ming

    2004-01-01

    Objective: To study the methods of prostatic arteriography and evaluate the arteriographic appearance of prostatic blood supply. Methods: Selective and super-selective prostatic arteriographies were performed in 62 patients with benign prostatic hyperplasia and prostatic cancer. Results: The prostatic blood supply originated mainly from inferior vesical artery or internal pudendal artery or prostatic artery (80%). Prostatic arteriography could be performed successfully with skillful catheterization and high resolution DSA. Conclusions: Prostatic arteriography is helpful for evaluating the origin and quantity of prostate vasculature and important to differentiate benign prostatic hyperplasia from prostatic cancer

  20. Computed tomography appearances of sclerosing encapsulating peritonitis

    International Nuclear Information System (INIS)

    George, C.; Al-Zwae, K.; Nair, S.; Cast, J.E.I.

    2007-01-01

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP

  1. Rapid Material Appearance Acquisition Using Consumer Hardware

    Czech Academy of Sciences Publication Activity Database

    Filip, Jiří; Vávra, Radomír; Krupička, Mikuláš

    2014-01-01

    Roč. 14, č. 10 (2014), s. 19785-19805 ISSN 1424-8220 R&D Projects: GA ČR(CZ) GA14-02652S; GA ČR(CZ) GA14-10911S; GA ČR GAP103/11/0335 Grant - others:EC FP7, European Reintegration Grant(BE) 239294 Institutional support: RVO:67985556 Keywords : measurement setup * material appearance * BTF * ABRDF * visual psychophysics Subject RIV: BD - Theory of Information Impact factor: 2.245, year: 2014 http://library.utia.cas.cz/separaty/2014/RO/filip-0433583.pdf

  2. An intragastric trichobezoar: computerised tomographic appearance.

    Directory of Open Access Journals (Sweden)

    Morris B

    2000-04-01

    Full Text Available A 26-year-old lady presented with a history of abdominal pain and distension since two months. The ultrasound examination showed an epigastric mass, which was delineated as a filling defect in the stomach on barium studies. The computerised tomographic scan showed a gastric mass with pockets of air in it, without post-contrast enhancement. This case highlights the characteristic appearance on computerised tomography of a bezoar within the stomach, a feature that is not commonly described in medical literature.

  3. CT appearance of amiodarone-induced pneumonitis

    International Nuclear Information System (INIS)

    Nicholson, A.A.; Hayward, C.

    1989-01-01

    Basal peripheral pleuroparenchymal opacities are described on CT of early cryptogenic fibrosing alveolitis, asbestosis and bleomycin pneumonitis. These diseases may be caused by free radical effects on phospholipid metabolism causing cell wall damage. Amiodarone hydrochloride alters phospholipid synthesis metabolically. Amiodarone pneumonitis might be expected to show similar CT appearances. Sixteen patients who have developed new respiratory symptoms while taking amiodarone have been scanned prone and supine and at inspiration and expiration by means of a scanner with 2-mm sections at 1-cm intervals. All have been previously healthy nonsmokers with no relevant occupational history. Previous chest radiographs have been normal. Results are presented

  4. Computed tomography appearances of sclerosing encapsulating peritonitis

    Energy Technology Data Exchange (ETDEWEB)

    George, C. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)]. E-mail: cheriangeorge@hotmail.com; Al-Zwae, K. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Nair, S. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Cast, J.E.I. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)

    2007-08-15

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP.

  5. Appearance-related bullying and skin disorders.

    Science.gov (United States)

    Magin, Parker

    2013-01-01

    Bullying encompasses verbal aggression, physical aggression, and social exclusion. It involves "harm-doing" that is carried out repeatedly, over time, and within a relationship, involving a power imbalance between the bully and the bullied. Being bullied may have considerable adverse sequelae, including psychologic or psychiatric harm. Much bullying is appearance-related, and it would be surprising if some individuals with skin disease were not bullied given the high visibility of skin diseases. The limited evidence available does suggest that individuals with skin disease, particularly those with acne, psoriasis, and atopic dermatitis, are often bullied, which can adversely affect them psychologically. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Photoinduced High-Frequency Charge Oscillations in Dimerized Systems

    Science.gov (United States)

    Yonemitsu, Kenji

    2018-04-01

    Photoinduced charge dynamics in dimerized systems is studied on the basis of the exact diagonalization method and the time-dependent Schrödinger equation for a one-dimensional spinless-fermion model at half filling and a two-dimensional model for κ-(bis[ethylenedithio]tetrathiafulvalene)2X [κ-(BEDT-TTF)2X] at three-quarter filling. After the application of a one-cycle pulse of a specifically polarized electric field, the charge densities at half of the sites of the system oscillate in the same phase and those at the other half oscillate in the opposite phase. For weak fields, the Fourier transform of the time profile of the charge density at any site after photoexcitation has peaks for finite-sized systems that correspond to those of the steady-state optical conductivity spectrum. For strong fields, these peaks are suppressed and a new peak appears on the high-energy side, that is, the charge densities mainly oscillate with a single frequency, although the oscillation is eventually damped. In the two-dimensional case without intersite repulsion and in the one-dimensional case, this frequency corresponds to charge-transfer processes by which all the bonds connecting the two classes of sites are exploited. Thus, this oscillation behaves as an electronic breathing mode. The relevance of the new peak to a recently found reflectivity peak in κ-(BEDT-TTF)2X after photoexcitation is discussed.

  7. About oscillations in the system of K0 mesons

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    2011-01-01

    This work considers K 0 -, K 0 bar - meson mixings and oscillations via K 1 0 , K 2 0 - meson states at strangeness violation by the weak interactions and K 1 0 -, K 2 0 - meson mixings and oscillations via K S -, K L - meson states at CP violation by the weak interactions without and with taking into account decay widths. We work in the framework of the masses mixing scheme. It is shown that K 1 0 -(K S -) meson states appear at big distances from the K 0 -mesons source after their decays (τ L ≥ τ S (τ 2 ≥τ 1 )) due to oscillations of residual K 2 0 (K L ) mesons and then again we see short-living K 1 0 (K S ) mesons. It is implied that K L ↔K S meson oscillations are absent. The case is also considered when at CP violation unitarity is violated, but orthogonality of K S , K L states remains. The general expressions for probabilities of meson oscillations (transitions) are given

  8. Appearance detection device for fuel assembly

    International Nuclear Information System (INIS)

    Matsuoka, Toshihiro

    1998-01-01

    The prevent invention provides an appearance detection device which improves accuracy of images on a display and facilitates editing and selection of images upon detection of appearance of a reactor fuel assembly. Namely, the device of the present invention comprises (1) television cameras movable along fuel assemblies of a reactor, (2) a detection means for detecting the positions of the television cameras, (3) a convertor for converting analog image signals of the television cameras to digital image signals, (4) a memory means for sampling a predetermined portion of the images of the television camera and storing it together with the position signal obtained by the detection means and (5) a computer for selecting a plurality of images and positions from the above-mentioned means and joining them to one or a plurality of static images of the fuel assembly. At least two television cameras are disposed oppositely with each other. Then, position signals of the television cameras are designated by the stored sampling signals, and the fuel assembly at the position can be displayed quickly. It is scrolled, compressed or enlarged and formed into images. (I.S.)

  9. Rapid Material Appearance Acquisition Using Consumer Hardware

    Directory of Open Access Journals (Sweden)

    Jiří Filip

    2014-10-01

    Full Text Available A photo-realistic representation of material appearance can be achieved by means of bidirectional texture function (BTF capturing a material’s appearance for varying illumination, viewing directions, and spatial pixel coordinates. BTF captures many non-local effects in material structure such as inter-reflections, occlusions, shadowing, or scattering. The acquisition of BTF data is usually time and resource-intensive due to the high dimensionality of BTF data. This results in expensive, complex measurement setups and/or excessively long measurement times. We propose an approximate BTF acquisition setup based on a simple, affordable mechanical gantry containing a consumer camera and two LED lights. It captures a very limited subset of material surface images by shooting several video sequences. A psychophysical study comparing captured and reconstructed data with the reference BTFs of seven tested materials revealed that results of our method show a promising visual quality. Speed of the setup has been demonstrated on measurement of human skin and measurement and modeling of a glue dessication time-varying process. As it allows for fast, inexpensive, acquisition of approximate BTFs, this method can be beneficial to visualization applications demanding less accuracy, where BTF utilization has previously been limited.

  10. Forced Oscillation Technique and Childhood Asthma

    Directory of Open Access Journals (Sweden)

    Hiroyuki Mochizuki

    2012-01-01

    Full Text Available Most infants and preschool children are not able to voluntarily perform the physiological maneuvers required to complete the pulmonary function tests that are used in adults and older children. Recently, commercial devices using forced oscillation technique (FOT suitable for young children have become available. In devices with FOT, an oscillation pressure wave is generated by a loud speaker, is applied to the respiratory system, usually at the mouth, and the resulting pressure-flow relationship is analyzed in terms of impedance (Zrs. Zrs encompasses both resistance (Rrs and reactance (Xrs. Rrs is calculated from pressure and flow signals, and is a measure of central and peripheral airway caliber. Xrs is derived from the pressure in the phase with volume and is related to compliance (Crs and inertance (Irs. These parameters individually indicate the condition of the small and large airways in each patient and indirectly suggest the presence of airway inflammation. It is agreed that the clinical diagnostic capacity of FOT is comparable to that of spirometry. One of the advantages of FOT is that minimal cooperation of the patient is needed and no respiratory maneuvers are required. The use of FOT should be considered in patients in whom spirometry or other pulmonary function tests cannot be performed or in cases where the results of other tests appear to be unreliable. In addition, this approach is effective in assessing bronchial hyperresponsiveness. Considering these qualities, FOT is a useful method to study pulmonary function in preschool children with asthma.

  11. Flashing oscillation in pool water

    International Nuclear Information System (INIS)

    Takamasa, Tomoji; Kondo, Koichi; Hazuku, Tatsuya

    1996-01-01

    This paper presents an experimental study of high-pressure saturated water discharging into the pool water. The purpose of the experiment is to clarify the phenomena that occur in blow-down of high-pressure saturated water from the pressure vessel into the water-filled containment in the case of a wall-crack accident or a LOCA in an advanced reactor. The results revealed that a flashing oscillation (FO) occurs when high-pressure saturated water discharges into the pool water, under specified experimental settings. The range of the flashing oscillates between a point very close to and some distance from the vent hole. The pressures in the vent tube and pool water vary according to the flashing oscillation. The pressure oscillation and frequency of flashing position might be caused by the balancing action between the supply of saturated water, flashing at the control volume and its condensation on the steam-water interface. A linear analysis was conducted using a spherical flashing bubble model. The period of the flashing oscillation in the experiments can be explained by theoretical analysis

  12. Neutrino oscillations at proton accelerators

    International Nuclear Information System (INIS)

    Michael, Douglas

    2002-01-01

    Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino oscillations. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex oscillation phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino oscillations could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of oscillation phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino oscillation experiments

  13. Neutrino Oscillations at Proton Accelerators

    Science.gov (United States)

    Michael, Douglas

    2002-12-01

    Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino oscillations. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex oscillation phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino oscillations could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of oscillation phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino oscillation experiments.

  14. Perceived functional impact of abnormal facial appearance.

    Science.gov (United States)

    Rankin, Marlene; Borah, Gregory L

    2003-06-01

    Functional facial deformities are usually described as those that impair respiration, eating, hearing, or speech. Yet facial scars and cutaneous deformities have a significant negative effect on social functionality that has been poorly documented in the scientific literature. Insurance companies are declining payments for reconstructive surgical procedures for facial deformities caused by congenital disabilities and after cancer or trauma operations that do not affect mechanical facial activity. The purpose of this study was to establish a large, sample-based evaluation of the perceived social functioning, interpersonal characteristics, and employability indices for a range of facial appearances (normal and abnormal). Adult volunteer evaluators (n = 210) provided their subjective perceptions based on facial physical appearance, and an analysis of the consequences of facial deformity on parameters of preferential treatment was performed. A two-group comparative research design rated the differences among 10 examples of digitally altered facial photographs of actual patients among various age and ethnic groups with "normal" and "abnormal" congenital deformities or posttrauma scars. Photographs of adult patients with observable congenital and posttraumatic deformities (abnormal) were digitally retouched to eliminate the stigmatic defects (normal). The normal and abnormal photographs of identical patients were evaluated by the large sample study group on nine parameters of social functioning, such as honesty, employability, attractiveness, and effectiveness, using a visual analogue rating scale. Patients with abnormal facial characteristics were rated as significantly less honest (p = 0.007), less employable (p = 0.001), less trustworthy (p = 0.01), less optimistic (p = 0.001), less effective (p = 0.02), less capable (p = 0.002), less intelligent (p = 0.03), less popular (p = 0.001), and less attractive (p = 0.001) than were the same patients with normal facial

  15. A search for bar νe appearance from stopped π+ and μ+ decay at LAMPF

    International Nuclear Information System (INIS)

    Fujikawa, B.K.

    1990-01-01

    The author reports on a recent search for bar ν e appearance from stopped π + → μ + ν μ and μ + → e + ν e bar ν μ decay made by the LAMPF experiment E645. The appearance of bar ν e may occur from bar ν μ → bar ν e , ν e → bar ν eL , or ν μ → bar ν eL oscillations. Appearance may also occur from rare μ + → e + bar ν e ν μ decay, which is allowed by a multiplicative lepton charge conservation law. The neutrino energies range from E ν = 0 to 52.8MeV. The neutrino detector, which is located 26.1 meters from the neutrino source, consists of a segmented liquid scintillator and proportional drift tube central detector surrounded by both active and passive shielding. The central detector detects bar ν e through the bar ν e p → ne + Charge Current (CC) reaction, which is signaled by the direct detection of the final state positron and neutron. The hydrogen-rich liquid scintillators act as free proton targets for the bar ν e p CC reaction. The neutrons are detected through radiative neutron capture on gadolinium. He finds no evidence for bar ν e appearance in the first year of running. New limits on the bar ν μ , ν e , ν μ yields bar ν e oscillation parameters and the rare μ + → e + bar ν e ν μ decay branching ratio are presented

  16. Abdominal retained surgical sponges: CT appearance

    Energy Technology Data Exchange (ETDEWEB)

    Kalovidouris, A.; Kehagias, D.; Moulopoulos, L.; Gouliamos, A.; Pentea, S.; Vlahos, L. [Department of Radiology, University of Athens (Greece)

    1999-09-01

    Retention of surgical sponges is rare. They cause either an aseptic reaction without significant symptoms or an exudative reaction which results in early but nonspecific symptoms. Computed tomography is very useful for recognition of retained sponges. The appearance of retained sponges is widely variable. Air trapping into a surgical sponge results in the spongiform pattern which is characteristic but unfortunately uncommon. A low-density, high-density, or complex mass is found in the majority of cases, but these patterns are not specific. Sometimes, a thin high-density capsule may be seen. Rim or internal calcification is a rare finding. Finally, a radiopaque marker is not a reliable sign. Differentiation from abscess and hematoma is sometimes difficult. (orig.) With 11 figs., 12 refs.

  17. Abdominal retained surgical sponges: CT appearance

    International Nuclear Information System (INIS)

    Kalovidouris, A.; Kehagias, D.; Moulopoulos, L.; Gouliamos, A.; Pentea, S.; Vlahos, L.

    1999-01-01

    Retention of surgical sponges is rare. They cause either an aseptic reaction without significant symptoms or an exudative reaction which results in early but nonspecific symptoms. Computed tomography is very useful for recognition of retained sponges. The appearance of retained sponges is widely variable. Air trapping into a surgical sponge results in the spongiform pattern which is characteristic but unfortunately uncommon. A low-density, high-density, or complex mass is found in the majority of cases, but these patterns are not specific. Sometimes, a thin high-density capsule may be seen. Rim or internal calcification is a rare finding. Finally, a radiopaque marker is not a reliable sign. Differentiation from abscess and hematoma is sometimes difficult. (orig.)

  18. Visualising the environmental appearance of audio products

    Energy Technology Data Exchange (ETDEWEB)

    Stilma, M. [Univ. of Twente, Enschede (Netherlands); Stevels, A. [Delft Univ. of Technology, Delft (Netherlands)]|[Philips Consumer Electronics, Eindhoven (Netherlands); Christiaans, H.; Kandachar, P. [Delft Univ. of Technology, Delft (Netherlands)

    2004-07-01

    Can environmental friendliness be communicated by the design style and appearance of products? (such as form, colour, style or material)? Consumers are interested in buying environmental products and design styles might be used as communicative tools. However, current 'green' products show something else. Environmental aspects are chiefly promoted by marketing programs based on technical items like the use of materials, hazardous substances, energy consumption, etc. By a qualitative and exploratory research the environmental design styles according to consumers' opinions were analysed with larger audio products as case study. Visible distinctive differences can be identified between the most and the least environmental rated products. A 'Green flagship', which claims to be environmentally orientated, wasn't recognised as such by consumers. And women and men perceive environmental friendliness in another way. From this research can be concluded that more attention is needed to visualise the good technical environmental performance of products. (orig.)

  19. Computed tomographic appearance of resectable pancreatic carcinoma

    International Nuclear Information System (INIS)

    Itai, Y.; Araki, T.; Tasaka, A.; Maruyama, M.

    1982-01-01

    Thirteen patients with resectable pancreatic carcinoma were examined by computed tomography (CT). Nine had a mass, 2 had dilatation of the main pancreatic duct, 1 appeared to have ductal dilatation, and 1 had no sign of abnormality. Resectable carcinoma was diagnosed retrospectively in 8 cases, based on the following criteria: a mass with a distinct contour, frequently containing a tiny or irregular low-density area and accompanied by dilatation of the caudal portion of the main pancreatic duct without involvement of the large vessels, liver, or lymph nodes. Including unresectable cancer, chronic pancreatitis, and obstructive jaundice from causes other than cancer, the false-positive rate was less than 6%. However, a small cancer without change in pancreatic contour is difficult to detect with CT

  20. Statistical shape and appearance models of bones.

    Science.gov (United States)

    Sarkalkan, Nazli; Weinans, Harrie; Zadpoor, Amir A

    2014-03-01

    When applied to bones, statistical shape models (SSM) and statistical appearance models (SAM) respectively describe the mean shape and mean density distribution of bones within a certain population as well as the main modes of variations of shape and density distribution from their mean values. The availability of this quantitative information regarding the detailed anatomy of bones provides new opportunities for diagnosis, evaluation, and treatment of skeletal diseases. The potential of SSM and SAM has been recently recognized within the bone research community. For example, these models have been applied for studying the effects of bone shape on the etiology of osteoarthritis, improving the accuracy of clinical osteoporotic fracture prediction techniques, design of orthopedic implants, and surgery planning. This paper reviews the main concepts, methods, and applications of SSM and SAM as applied to bone. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Modelling the appearance of heritage metallic surfaces

    Directory of Open Access Journals (Sweden)

    L. MacDonald

    2014-06-01

    Full Text Available Polished metallic surfaces exhibit a high degree of specularity, which makes them difficult to reproduce accurately. We have applied two different techniques for modelling a heritage object known as the Islamic handbag. Photogrammetric multi-view stereo enabled a dense point cloud to be extracted from a set of photographs with calibration targets, and a geometrically accurate 3D model produced. A new method based on photometric stereo from a set of images taken in an illumination dome enabled surface normals to be generated for each face of the object and its appearance to be rendered, to a high degree of visual realism, when illuminated by one or more light sources from any angles. The specularity of the reflection from the metal surface was modelled by a modified Lorentzian function.

  2. Animal biometrics: quantifying and detecting phenotypic appearance.

    Science.gov (United States)

    Kühl, Hjalmar S; Burghardt, Tilo

    2013-07-01

    Animal biometrics is an emerging field that develops quantified approaches for representing and detecting the phenotypic appearance of species, individuals, behaviors, and morphological traits. It operates at the intersection between pattern recognition, ecology, and information sciences, producing computerized systems for phenotypic measurement and interpretation. Animal biometrics can benefit a wide range of disciplines, including biogeography, population ecology, and behavioral research. Currently, real-world applications are gaining momentum, augmenting the quantity and quality of ecological data collection and processing. However, to advance animal biometrics will require integration of methodologies among the scientific disciplines involved. Such efforts will be worthwhile because the great potential of this approach rests with the formal abstraction of phenomics, to create tractable interfaces between different organizational levels of life. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Synthesized Mammography: Clinical Evidence, Appearance, and Implementation

    Directory of Open Access Journals (Sweden)

    Melissa A. Durand

    2018-04-01

    Full Text Available Digital breast tomosynthesis (DBT has improved conventional mammography by increasing cancer detection while reducing recall rates. However, these benefits come at the cost of increased radiation dose. Synthesized mammography (s2D has been developed to provide the advantages of DBT with nearly half the radiation dose. Since its F.D.A. approval, multiple studies have evaluated the clinical performance of s2D. In clinical practice, s2D images are not identical to conventional 2D images and are designed for interpretation with DBT as a complement. This article reviews the present literature to assess whether s2D is a practical alternative to conventional 2D, addresses the differences in mammographic appearance of findings, and provides suggestions for implementation into clinical practice.

  4. Radiological appearances in the near-drowned

    International Nuclear Information System (INIS)

    Reinhardt, K.

    1981-01-01

    Three patients who were unconscious when rescued from drowning had radiographic studies of their lungs carried out after several hours, or on the following day. The findings had to be interpreted as pulmonary oedema. The most seriously affected patient showed the picture of massive acute interstitial oedema on the second day. After initial regression, coarse shadows developed, indicating the alveolar form of pulmonary oedema. The sputum contained candida, but there was no evidence of pulmonary candidiasis. In two patients there were transient signs of limited atelectases. Two patients were re-examined after five years. There were no features which could be interpreted as a consequence of the drowning episode. The radiographic appearances showed minor changes which could be due to mild pulmonary fibrosis. (orig.) [de

  5. Radiological appearances in the near-drowned

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, K.

    1981-10-01

    Three patients who were unconscious when rescued from drowning had radiographic studies of their lungs carried out after several hours, or on the following day. The findings had to be interpreted as pulmonary oedema. The most seriously affected patient showed the picture of massive acute interstitial oedema on the second day. After initial regression, coarse shadows developed, indicating the alveolar form of pulmonary oedema. The sputum contained candida, but there was no evidence of pulmonary candidiasis. In two patients there were transient signs of limited atelectases. Two patients were re-examined after five years. There were no features which could be interpreted as a consequence of the drowning episode. The radiographic appearances showed minor changes which could be due to mild pulmonary fibrosis.

  6. Synthesized Mammography: Clinical Evidence, Appearance, and Implementation.

    Science.gov (United States)

    Durand, Melissa A

    2018-04-04

    Digital breast tomosynthesis (DBT) has improved conventional mammography by increasing cancer detection while reducing recall rates. However, these benefits come at the cost of increased radiation dose. Synthesized mammography (s2D) has been developed to provide the advantages of DBT with nearly half the radiation dose. Since its F.D.A. approval, multiple studies have evaluated the clinical performance of s2D. In clinical practice, s2D images are not identical to conventional 2D images and are designed for interpretation with DBT as a complement. This article reviews the present literature to assess whether s2D is a practical alternative to conventional 2D, addresses the differences in mammographic appearance of findings, and provides suggestions for implementation into clinical practice.

  7. Musculoskeletal desmoid tumours: Diagnostic imaging appearances

    International Nuclear Information System (INIS)

    Liu, Daniel; Perera, Warren; Schlicht, Stephen; Choong, Peter; Slavin, John; Pianta, Marcus

    2015-01-01

    This study aimed to discuss the role medical imaging has on diagnosis of musculoskeletal desmoid tumours and to describe their radiological appearances on various imaging modalities. Imaging of histologically proven cases of desmoid tumours at St. Vincent's Hospital Melbourne were obtained via picture archiving communication system (PACS) and then assessed by two musculoskeletal radiologists. Suitable imagings were obtained from PACS. All imaging chosen was de-identified. Desmoid tumours can occur in many areas of the body. Imaging plays an important role in the diagnosis of these tumours and magnetic resonance imaging has been the gold standard for imaging and is the most accurate in terms of assessing tumour margins and involvement of surrounding structure.

  8. Restoration of oscillation in network of oscillators in presence of direct and indirect interactions

    Energy Technology Data Exchange (ETDEWEB)

    Majhi, Soumen; Bera, Bidesh K. [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India); Bhowmick, Sourav K. [Department of Electronics, Asutosh College, Kolkata-700026 (India); Ghosh, Dibakar, E-mail: diba.ghosh@gmail.com [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India)

    2016-10-23

    The suppression of oscillations in coupled systems may lead to several unwanted situations, which requires a suitable treatment to overcome the suppression. In this paper, we show that the environmental coupling in the presence of direct interaction, which can suppress oscillation even in a network of identical oscillators, can be modified by introducing a feedback factor in the coupling scheme in order to restore the oscillation. We inspect how the introduction of the feedback factor helps to resurrect oscillation from various kinds of death states. We numerically verify the resurrection of oscillations for two paradigmatic limit cycle systems, namely Landau–Stuart and Van der Pol oscillators and also in generic chaotic Lorenz oscillator. We also study the effect of parameter mismatch in the process of restoring oscillation for coupled oscillators. - Highlights: • Amplitude death is observed using direct and indirect coupling. • Revival of oscillation using feedback parameter is discussed. • Restoration of oscillation is observed in limit cycle and chaotic systems.

  9. CT appearances of emphysema and clinical application

    International Nuclear Information System (INIS)

    Wang Xinlian; Ma Daqing; Chen Budong; He Wen; Guan Yansheng; Zhang Yansong; Tang Hongqu; Wang Zhenguang

    2006-01-01

    Objective: To investigate CT appearances of different types of emphysema and to determine the clinic value for differential diagnosis. Methods: Twenty-three specimens with emphysema selected from 33 autopsy specimens were included in this study. All specimens were inflated and fixed by Heitzman's method, then examined by spiral CT scan. The CT appearances of different types of emphysema in every specimen were analyzed. After the specimens were cut into 10 mm thickness slices, the CT- pathologic correlation was done. Fifteen clinical cases confirmed by pathology or clinical process were all performed spiral CT scan and analyzed, including emphysema-accompanying pneumonia 11 cases, emphysema-accompanying nodule 4 cases. Result: Centriacinar emphysema (CAE)can be seen in 21 of 23 specimens, pancinar emphysema(PAE) can be seen in 5 of 23 specimens, all coexisting with CAE. Distal acinar emphysema(DAE) can be seen in 19 of 23 specimens, irregular emphysema can be seen in 3 of 23 specimens. In all specimens, emphysema can be seen in bilateral lung fields, distributing similarly. Seventeen of 23 eases (17/23) showed no less than two types of emphysema. Fourteen cases of emphysema- accompanying pneumonia (clinic: 11 cases, specimen: 3 cases) showed 'pseudocavity' or 'pseudohoneycombing' (emphysema lesion that had not been filled in the consolidation). Four eases of emphysema-accompanying nodule showed 'pseudopleuralhollow' (wall of DAE or bulla connecting with nodule). Conclusion: The CT manifestations of emphysema, the characteristics of distribution and multi- type of emphysema coexisting can help differentiate cystic air space diseases. The characteristics of complications of emphysema, the 'pseudocavity', 'pseudohoneycombing' and 'pseudopleuralhollow', may be help for differential diagnosis. (authors)

  10. Relaxation oscillations in stimulated Raman scattering

    International Nuclear Information System (INIS)

    Kachen, G.I.; Lowdermilk, W.H.

    1977-01-01

    Light pulses created by stimulated Raman scattering having been found to exhibit a complex time dependence which resembles relaxation oscillations. A focused laser pulse generated both forward and backward Raman emissions which appeared as a series of pulses with durations much shorter than the incident laser pulse. Time dependence of the Raman emission was observed directly by use of a streak camera. The number of observed pulses increased with the intensity of the incident pulse, while separation of the pulses in time depended on the length of the focal region. Beam focusing was incorporated in the coupled wave equations for stimulated Raman scattering. These rate equations were then solved numerically, and the results are in good qualitative agreement with the experimental observations. The short Raman pulses are created by a process associated with depletion of the incident laser pulse. This process occurs under a broad range of conditions

  11. New results from the T2K neutrino oscillation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Oser, Scott M., E-mail: oser@phas.ubc.ca [University of British Columbia, Department of Physics and Astronomy (Canada); Collaboration: T2K Collaboration

    2013-03-15

    The T2K experiment searches for the appearance of electron neutrinos in a muon neutrino beam. The rate of this process is sensitive to the neutrino mixing parameter {theta}{sub 13}. Recent measurements that {theta}{sub 13} {ne} 0 imply that {nu}{sub {mu}} {yields} {nu}{sub e} oscillations should be observable. Using all data through May 15, 2012 the T2K experiment has detected 10 candidate {nu}{sub e} events, with an expected background for {theta}{sub 13} = 0 of 2.73{+-}0.37 events. This 3.2{sigma} excess of {nu}{sub e} events is the strongest indication to date for appearance of electron neutrinos in a neutrino oscillation experiment, and for normal mass hierarchy and {delta}{sub CP} = 0 yields 0.059 < sin{sup 2} 2{theta}{sub 13} < 0.164 at the 68 % C.L.

  12. Nonstationary oscillations in gyrotrons revisited

    International Nuclear Information System (INIS)

    Dumbrajs, O.; Kalis, H.

    2015-01-01

    Development of gyrotrons requires careful understanding of different regimes of gyrotron oscillations. It is known that in the planes of the generalized gyrotron variables: cyclotron resonance mismatch and dimensionless current or cyclotron resonance mismatch and dimensionless interaction length complicated alternating sequences of regions of stationary, periodic, automodulation, and chaotic oscillations exist. In the past, these regions were investigated on the supposition that the transit time of electrons through the interaction space is much shorter than the cavity decay time. This assumption is valid for short and/or high diffraction quality resonators. However, in the case of long and/or low diffraction quality resonators, which are often utilized, this assumption is no longer valid. In such a case, a different mathematical formalism has to be used for studying nonstationary oscillations. One example of such a formalism is described in the present paper

  13. Prediction of pilot induced oscillations

    Directory of Open Access Journals (Sweden)

    Valentin PANĂ

    2011-03-01

    Full Text Available An important problem in the design of flight-control systems for aircraft under pilotedcontrol is the determination of handling qualities and pilot-induced oscillations (PIO tendencieswhen significant nonlinearities exist in the vehicle description. The paper presents a method to detectpossible pilot-induced oscillations of Category II (with rate and position limiting, a phenomenonusually due to a misadaptation between the pilot and the aircraft response during some tasks in whichtight closed loop control of the aircraft is required from the pilot. For the analysis of Pilot in the LoopOscillations an approach, based on robust stability analysis of a system subject to uncertainparameters, is proposed. In this analysis the nonlinear elements are substituted by linear uncertainparameters. This approach assumes that PIO are characterized by a limit cycle behavior.

  14. Magnetically insulated transmission line oscillator

    Science.gov (United States)

    Bacon, L.D.; Ballard, W.P.; Clark, M.C.; Marder, B.M.

    1987-05-19

    A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields are produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap. 11 figs.

  15. Body Image and the Appearance Culture Among Adolescent Girls and Boys: An Examination of Friend Conversations, Peer Criticism, Appearance Magazines, and the Internalization of Appearance Ideals

    Science.gov (United States)

    Jones, Diane Carlson; Vigfusdottir, Thorbjorg Helga; Lee, Yoonsun

    2004-01-01

    This research evaluates the contributions of three dimensions of appearance culture (appearance magazine exposure, appearance conversations with friends, and peer appearance criticism) and body mass index (BMI) to internalization of appearance ideals and body image dissatisfaction. Four hundred thirty-three girls and 347 boys in Grades 7 through…

  16. Solar-like oscillations from the depths of the red-giant star KIC4351319 observed with Kepler

    DEFF Research Database (Denmark)

    di Mauro, M.P.; Cardini, D.; Catanzaro, G.

    2011-01-01

    with the accurate determination of the atmospheric parameters (effective temperature, gravity and metallicity), provided by additional ground-based spectroscopic observations, enabled us to theoretically interpret the observed oscillation spectrum. KIC 4351319 appears to oscillate with a well-defined solar-type p...

  17. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  18. Oscillating liquid flow ICF Reactor

    International Nuclear Information System (INIS)

    Petzoldt, R.W.

    1990-01-01

    Oscillating liquid flow in a falling molten salt inertial confinement fusion reactor is predicted to rapidly clear driver beam paths of residual liquid droplets. Oscillating flow will also provide adequate neutron and x-ray protection for the reactor structure with a short (2-m) fall distance permitting an 8 Hz repetition rate. A reactor chamber configuration is presented with specific features to clear the entire heavy-ion beam path of splashed molten salt. The structural components, including the structure between beam ports, are shielded. 3 refs., 12 figs

  19. Neutrino oscillation measurements with reactors

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, R.D. [W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2010-11-01

    Since the first direct observations of antineutrino events by Reines and Cowan in the 1950's, nuclear reactors have been an important tool in the study of neutrino properties. More recently, the study of neutrino oscillations has been a very active area of research. The pioneering observation of oscillations by the KamLAND experiment has provided important information on the neutrino masses and the neutrino mixing matrix. New experiments to study the remaining unknown mixing angle are currently under development. These recent studies and potential future developments will be discussed.

  20. Simultaneous excitation of the snake-like oscillations and the m/n = 1/1 resistive interchange modes around the iota = 1 rational surface just after hydrogen pellet injections in LHD plasmas

    Science.gov (United States)

    Bando, T.; Ohdachi, S.; Suzuki, Y.; Sakamoto, R.; Narushima, Y.; Takemura, Y.; Watanabe, K. Y.; Sakakibara, S.; Du, X. D.; Motojima, G.; Tanaka, K.; Morisaki, T.; LHD Experiment Group

    2018-01-01

    Two types of oscillation phenomena are found just after hydrogen ice pellet injections in the Large Helical Device (LHD). Oscillation phenomena appear when the deposition profile of a hydrogen ice pellet is localized around the rotational transform ι = 1 rational surface. At first, damping oscillations (type-I) appear only in the soft X-ray (SX) emission. They are followed by the second type of oscillations (type-II) where the magnetic fluctuations and density fluctuations synchronized to the SX fluctuations are observed. Both oscillations have poloidal/toroidal mode number, m/n = 1/1. Since the type-II oscillations appear when the local pressure is large and/or the local magnetic Reynold's number is small, it is reasonable that type-II oscillations are caused by the resistive interchange modes. Because both types of oscillations appear simultaneously at slightly different locations and with slightly different frequencies, it is certain that type-I oscillations are different from type-II oscillations, which we believe is the MHD instability. It is possible that type-I oscillations are caused by the asymmetric concentration of the impurities. The type-I oscillations are similar to the impurity snake phenomena observed in tokamaks though type-I oscillations survive only several tens of milliseconds in LHD.

  1. ALG-2 oscillates in subcellular localization, unitemporally with calcium oscillations

    DEFF Research Database (Denmark)

    la Cour, Jonas Marstrand; Mollerup, Jens; Berchtold, Martin Werner

    2007-01-01

    discovered that the subcellular distribution of a tagged version of ALG-2 could be directed by physiological external stimuli (including ATP, EGF, prostaglandin, histamine), which provoke intracellular Ca2+ oscillations. Cellular stimulation led to a redistribution of ALG-2 from the cytosol to a punctate...

  2. Conductance oscillation in graphene-nanoribbon-based electronic Fabry-Perot resonators

    International Nuclear Information System (INIS)

    Zhang Yong; Han Mei; Shen Linjiang

    2010-01-01

    By using the tight-binding approximation and the Green's function method, the quantum conductance of the Fabry-Perot-like electronic resonators composed of zigzag and metallic armchair edge graphene nanoribbons (GNRs) was studied numerically. Obtained results show that due to Fabry-Perot-like electronic interference, the conductance of the GNR resonators oscillates periodically with the Fermi energy. The effects of disorders and coupling between the electrodes and the GNR on conductance oscillations were explored. It is found that the conductance oscillations appear at the strong coupling and become resonant peaks as the coupling is very weak. It is also found that the strong disorders in the GNR can smear the conductance oscillation periods. In other words, the weak coupling and the strong disorders all can blur the conductance oscillations, making them unclearly distinguished.

  3. Sonographic appearance of anal cushions of hemorrhoids.

    Science.gov (United States)

    Aimaiti, Adilijiang; A Ba Bai Ke Re, Ma Mu Ti Jiang; Ibrahim, Irshat; Chen, Hui; Tuerdi, Maimaitituerxun; Mayinuer

    2017-05-28

    To evaluate the diagnostic value of different sonographic methods in hemorrhoids. Forty-two healthy volunteers and sixty-two patients with grades I-IV hemorrhoids received two different sonographic examinations from January 2013 to January 2016 at the First and Second Hospitals of Xinjiang Medical University in a prospective way. We analyzed the ultrasonographic findings of these participants and evaluated the outcomes. Resected grades III and IV hemorrhoid tissues were pathologically examined. The concordance of ultrasonographic results with pathology results was assessed with the Cohen's kappa coefficient. All healthy volunteers and all patients had no particular complications related to sonography. There were no statistically significant differences between the participants regarding age ( P = 0.5919), gender ( P = 0.4183), and persistent symptoms ( P > 0.8692). All healthy control participants had no special findings. However, 30 patients with hemorrhoids showed blood signals around the dentate line on ultrasonography. When grades I and II hemorrhoids were analyzed, there were no significant differences between transrectal ultrasound (TRUS), transperianal ultrasound (TPUS), and transvaginal ultrasound (TVUS) ( P > 0.05). Grades III and IV hemorrhoids revealed blood flow with different directions which could be observed as a "mosaic pattern". In patients with grades III and IV hemorrhoids, the number of patients with "mosaic pattern" as revealed by TRUS, TPUS and TVUS was 22, 12, and 4, respectively. Patients with grades III and IV disease presented with a pathologically abnormal cushion which usually appeared as a "mosaic pattern" in TPUS and an arteriovenous fistula in pathology. Subepithelial vessels of resected grades III and IV hemorrhoid tissues were manifested by obvious structural impairment and retrograde and ruptured changes of internal elastic lamina. Some parts of the Trietz's muscle showed hypertrophy and distortion. Arteriovenous fistulas and

  4. TOWARDS THRESHOLD FREQUENCY IN CHAOTIC COLPITTS OSCILLATOR

    DEFF Research Database (Denmark)

    Lindberg, Erik; Tamasevicius, Arunas; Mykolaitis, Gytis

    2007-01-01

    A novel version of chaotic Colpitts oscillator is described. Instead of a linear loss resistor, it includes an extra inductor and diode in the collector circuit of the transistor. The modified circuit in comparison with the common Colpitts oscillator may generate chaotic oscillations at the funda......A novel version of chaotic Colpitts oscillator is described. Instead of a linear loss resistor, it includes an extra inductor and diode in the collector circuit of the transistor. The modified circuit in comparison with the common Colpitts oscillator may generate chaotic oscillations...

  5. Herniographic appearance of the lateral inguinal fossa

    International Nuclear Information System (INIS)

    Ekberg, O.; Kesek, P.

    1987-01-01

    Herniography frequently reveals clinically undetected groin hernia. Thereby herniography contributes to the clinical work-up in patients with obscure groin pain. However, the distinction between clinically important and unimportant abnormalities within the lateral inguinal fossa can be difficult. This study was therefore designed in order to elucidate the herniographic appearance of the lateral inguinal fossa in patients with obscure groin pain. Herniographic findings were compared with laterality of the patients' symptoms. The lateral umbilical fold was visible in only 47% of the groins. A triangular shaped outpouching from the lateral inguinal fossa and a patent processus vaginalis were found with equal frequency on the left and right side. They were five times as frequent in men as in women. Their presence did not correlate with laterality of the patients' symptoms. Indirect hernias were almost twice as common on the symptomatic side as compared with the asymptomatic side. On the left side they were found twice as often in men as in women while there was no significant sex difference on the right side. Our results show that neither a patent processus vaginalis nor a triangular outpouching from the lateral inguinal fossa correlate with the laterality of the patients' symptoms while true indirect hernias do. (orig.)

  6. Calcified trichinosis of pectoral muscle: mammographic appearance

    International Nuclear Information System (INIS)

    Apesteguia, L.; Murillo, A.; Biurrun, J.; Garcia-Rostan, G.; Reta, A.; Dominguez, F.

    1995-01-01

    By mammographic screening we had detected six asymptomatic women who showed numerious tiny and well-delineated round to ovoid microcalcification superimposed on pectoral shadows, in the oblique medio-lateral (OML) view. Our objective was to achieve a better evaluation of these calcifications and investigate their origin. Magnified mammograms of pectoral muscles were done in the six women. A questionnaire concerning the patients' diets was also administered. Trichinella antibody titres were quantified by sero-agglutination. Microcalcifications within pectoral muscle fibres were demonstrated in all the cases. Five women admitted to having eaten home-made pork products in the past. One of them showed a slightly elevated antibody titre. We confirmed the suspected diagnosis of calcified trichinosis by a surgical biopsy of the pectoral muscle performed on one of the patients. We conclude that chronic calcified trichinosis of the pectoral muscle can be visualised in the OML view of a conventional mammogram. The mammographic appearance of this entity is very characteristic and biopsy would not be required for its diagnosis in the future. (orig.)

  7. Dermoscopic appearance of an amelanotic mucosal melanoma

    Science.gov (United States)

    Blum, Andreas; Beck-Zoul, Ulrike; Held, Laura; Haase, Sylvie

    2016-01-01

    Background Hypomelanotic or amelanotic melanomas are challenging to identify, especially at mucosal sites. The dermoscopic clues to the diagnosis of mucosal melanomas have been reported to be structureless zones with the presence of blue, gray, or white colors. Case A female in her seventies noted a new lesion on the inside of her right labia that first appeared two months prior. Her past medical history was significant for rheumatoid arthritis requiring ongoing treatment with methotrexate for 20 years and adalimumab for 10 years. After no response to two weeks of local treatment for suspected herpes simplex infection, her gynecologist performed a skin biopsy. Based on the histopathological diagnosis of an amelanotic melanoma (Breslow thickness of 1.3 mm) the patient was referred to dermatology for further assessment. Polarized dermoscopy revealed a distinct asymmetric, sharply demarcated homogenous white papule (4 × 5 mm) as well as polymorphous vessels. Conclusion Dermoscopy may aid in the diagnosis of amelanotic mucosal melanomas. Our case revealed a structureless white area and polymorphous vessels. Additional clues to the diagnosis were the advanced age of the patient and the clinical presentation of a new lesion. PMID:27867742

  8. Elastofibroma Dorsi: CT and MRI appearance

    International Nuclear Information System (INIS)

    Bonini, Claudio J.; Costamagna, Cecilia L.; Staffieri, Roberto; Villavicencio, Roberto L.; Milatich, Viviana

    2002-01-01

    Objective: To describe the findings of fibroelastomas by CT and MR imaging. Material and Methods: We studied 7 female patients, aged 60 to 75 years. All patients presented a unilateral soft tissue mass in the periscapular region (4 left sided and 3 right sided); one patient developed a contralateral lesion one year later. Four patients had pain and underwent surgical excision of the lesions; 2 patients underwent percutaneous biopsy and the last patient is under clinical and imaging follow-up. Results: The lesions had a tomographic density to muscle, but with the presence of hypodense bands corresponding to adipose tissue. After the administration of IV contrast (5 cases) density remained similar to that of muscle. By MR, in the T1 sequence, the lesions were isointense to muscle and had hyperintense linear areas corresponding to adipose tissue bands. In the FSE T2 sequences, the lesions appeared mildly hyperintense. After the administration of IV gadolinium, the T1 sequence with fat suppression showed marked enhancement of the tumors. There was no involvement of neighboring bony or muscle structures. Conclusion: CT and MRI are useful methods for the detection of periscapular fibroelastomas. (author)

  9. Electron Neutrino Appearance in the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Orchanian, Mhair-armen Hagop [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2012-01-01

    This thesis describes a search for ve appearance in the two-detector long-baseline MINOS neutrino experiment at Fermilab, based on a data set representing an exposure of 8.2×1020 protons on the NuMI target. The analysis detailed herein represents an increase in sensitivity to the θ13 mixing angle of approximately 25% over previous analyses, due to improvements in the event discriminant and fitting technique. Based on our observation, we constrain the value of θ13 further, finding 2 sin2θ 23 sin2θ 13< 0.12(0.20) at the 90% confidence level for δCP = 0 and the normal (inverted) neutrino mass hierarchy. The best-fit value is 2 sin2θ 23 sin2θ 13 = 0.041+0.047 -0.031(0.079+0.071 -0.053) under the same assumptions. We exclude the θ 13 = 0 hypothesis at the 89% confidence level.

  10. Calcified trichinosis of pectoral muscle: mammographic appearance

    Energy Technology Data Exchange (ETDEWEB)

    Apesteguia, L. [Servicio de Radiologia, Hospital Virgen del Camino, Pamplona (Spain); Murillo, A. [Servicio de Radiologia, Hospital Virgen del Camino, Pamplona (Spain); Biurrun, J. [Servicio de Radiologia, Hospital Virgen del Camino, Pamplona (Spain); Garcia-Rostan, G. [Servicio Anatomia Patologica, Hospital Virgen del Camino, Pamplona (Spain); Reta, A. [Servicio de Analisis Clinicos, Hospital Virgen del Camino, Pamplona (Spain); Dominguez, F. [Servicio Cirugia, Hospital Virgen del Camino, Pamplona (Spain)

    1995-12-31

    By mammographic screening we had detected six asymptomatic women who showed numerious tiny and well-delineated round to ovoid microcalcification superimposed on pectoral shadows, in the oblique medio-lateral (OML) view. Our objective was to achieve a better evaluation of these calcifications and investigate their origin. Magnified mammograms of pectoral muscles were done in the six women. A questionnaire concerning the patients` diets was also administered. Trichinella antibody titres were quantified by sero-agglutination. Microcalcifications within pectoral muscle fibres were demonstrated in all the cases. Five women admitted to having eaten home-made pork products in the past. One of them showed a slightly elevated antibody titre. We confirmed the suspected diagnosis of calcified trichinosis by a surgical biopsy of the pectoral muscle performed on one of the patients. We conclude that chronic calcified trichinosis of the pectoral muscle can be visualised in the OML view of a conventional mammogram. The mammographic appearance of this entity is very characteristic and biopsy would not be required for its diagnosis in the future. (orig.)

  11. How To Control Color Appearance With Instrumentation

    Science.gov (United States)

    Burns, Margaret E.

    1980-05-01

    Colorimetry, as defined by the International Commission on Illumination, is the measurement of colors, made possible by the properties of the eye and based on a set of conventions. Instrumentation for measuring object color, therefore, must be based on a human observer. The intent is to design an instrument that in effect responds as a person would, so that research development, production control and quality control areas have some means of assessing the acceptability of the appearance of a product. Investigations of a human observer's psychological response to color, and the manner in which visual observations are made, give the instrument designer and manufacturer data necessary to answer two questions: a. How can we put numbers (instrument read-out) on a perception that occurs in the brain of the observer? b. What can we learn from examination of a visual observing situation that will guide us in our design of an instrumental simulation of this situation? Involving as it does our own daily, almost unconscious, practice of making judgments concerning the things we see, the design and manufacture of color measurement instruments is an exceedingly interesting field. The advances being made concurrently today in research concerning human color vision and in optical and electronic technology will make possible increasingly useful instrumentation for quality control of product color.

  12. Search for “anomalies” from neutrino and anti-neutrino oscillations at $\\Delta_m^{2} ≈ 1eV^{2}$ with muon spectrometers and large LAr–TPC imaging detectors

    CERN Document Server

    Antonello, M; Baibussinov, B; Bilokon, H; Boffelli, F; Bonesini, M; Calligarich, E; Canci, N; Centro, S; Cesana, A; Cieslik, K; Cline, D B; Cocco, A G; Dequal, D; Dermenev, A; Dolfini, R; De Gerone, M; Dussoni, S; Farnese, C; Fava, A; Ferrari, A; Fiorillo, G; Garvey, G T; Gatti, F; Gibin, D; Gninenko, S; Guber, F; Guglielmi, A; Haranczyk, M; Holeczek, J; Ivashkin, A; Kirsanov, M; Kisiel, J; Kochanek, I; Kurepin, A; Łagoda, J; Lucchini, G; Louis, W C; Mania, S; Mannocchi, G; Marchini, S; Matveev, V; Menegolli, A; Meng, G; Mills, G B; Montanari, C; Nicoletto, M; Otwinowski, S; Palczewski, T J; Passardi, G; Perfetto, F; Picchi, P; Pietropaolo, F; Płonski, P; Rappoldi, A; Raselli, G L; Rossella, M; Rubbia, C; Sala, P; Scaramelli, A; Segreto, E; Stefan, D; Stepaniak, J; Sulej, R; Suvorova, O; Terrani, M; Tlisov, D; Van de Water, R G; Trinchero, G; Turcato, M; Varanini, F; Ventura, S; Vignoli, C; Wang, H G; Yang, X; Zani, A; Zaremba, K; Benettoni, M; Bernardini, P; Bertolin, A; Bozza, C; Brugnera, R; Cecchetti, A; Cecchini, S; Collazuol, G; Creti, P; Dal Corso, F; De Mitri, I; De Robertis, G; De Serio, M; Degli Esposti, L; Di Ferdinando, D; Dore, U; Dusini, S; Fabbricatore, P; Fanin, C; Fini, R A; Fiore, G; Garfagnini, A; Giacomelli, G; Giacomelli, R; Grella, G; Guandalini, C; Guerzoni, M; Kose, U; Laurenti, G; Laveder, M; Lippi, I; Loddo, F; Longhin, A; Loverre, P; Mancarella, G; Mandrioli, G; Margiotta, A; Marsella, G; Mauri, N; Medinaceli, E; Mengucci, A; Mezzetto, M; Michinelli, R; Muciaccia, M T; Orecchini, D; Paoloni, A; Pastore, A; Patrizii, L; Pozzato, M; Rescigno, R; Rosa, G; Simone, S; Sioli, M; Sirri, G; Spurio, M; Stanco, L; Stellacci, S; Surdo, A; Tenti, M; Togo, V; Ventura, M; Zago, M

    2012-01-01

    This proposal describes an experimental search for sterile neutrinos beyond the Standard Model with a new CERN-SPS neutrino beam. The experiment is based on two identical LAr-TPC's followed by magnetized spectrometers, observing the electron and muon neutrino events at 1600 and 300 m from the proton target. This project will exploit the ICARUS T600, moved from LNGS to the CERN "Far" position. An additional 1/4 of the T600 detector will be constructed and located in the "Near" position. Two spectrometers will be placed downstream of the two LAr-TPC detectors to greatly complement the physics capabilities. Spectrometers will exploit a classical dipole magnetic field with iron slabs, and a new concept air-magnet, to perform charge identification and muon momentum measurements in a wide energy range over a large transverse area. In the two positions, the radial and energy spectra of the nu_e beam are practically identical. Comparing the two detectors, in absence of oscillations, all cross sections and experimenta...

  13. Neutrino masses and neutrino oscillations

    CERN Document Server

    Di Lella, L

    2000-01-01

    These lectures review direct measurements of neutrino masses and the status of neutrino oscillation searches using both natural neutrino sources (the Sun and cosmic rays interacting in the Earth atmosphere) and artificial neutrinos (produced by nuclear reactors and accelerators). Finally, future experiments and plans are presented. (68 refs).

  14. Harmonic oscillator in Snyder space

    Indian Academy of Sciences (India)

    The harmonic oscillator in Snyder space is investigated in its classical and quantum versions. The classical trajectory is obtained and the semiclassical quantization from the phase space trajectories is discussed. An effective cut-off to high frequencies is found. The quantum version is developed and an equivalent usual ...

  15. Compressible flow in fluidic oscillators

    Science.gov (United States)

    Graff, Emilio; Hirsch, Damian; Gharib, Mory

    2013-11-01

    We present qualitative observations on the internal flow characteristics of fluidic oscillator geometries commonly referred to as sweeping jets in active flow control applications. We also discuss the effect of the geometry on the output jet in conditions from startup to supersonic exit velocity. Supported by the Boeing Company.

  16. Ellipsoidal basis for isotropic oscillator

    International Nuclear Information System (INIS)

    Kallies, W.; Lukac, I.; Pogosyan, G.S.; Sisakyan, A.N.

    1994-01-01

    The solutions of the Schroedinger equation are derived for the isotropic oscillator potential in the ellipsoidal coordinate system. The explicit expression is obtained for the ellipsoidal integrals of motion through the components of the orbital moment and Demkov's tensor. The explicit form of the ellipsoidal basis is given for the lowest quantum numbers. 10 refs.; 1 tab. (author)

  17. The relativistic harmonic oscillator reconsidered

    International Nuclear Information System (INIS)

    Hofsaess, T.

    1978-01-01

    The bound states of scalar quarks interacting through a scalar harmonic oscillator are investigated. In the presence of this interaction the dressed quark propagator differs substantially from the free one. This leads to a Bethe Salpeter equation which does not allow for any stable bound states of positive mass. (orig.) [de

  18. Inverse problem of solar oscillations

    International Nuclear Information System (INIS)

    Sekii, T.; Shibahashi, H.

    1987-01-01

    The authors present some preliminary results of numerical simulation to infer the sound velocity distribution in the solar interior from the oscillation data of the Sun as the inverse problem. They analyze the acoustic potential itself by taking account of some factors other than the sound velocity, and infer the sound velocity distribution in the deep interior of the Sun

  19. Sum rules for neutrino oscillations

    International Nuclear Information System (INIS)

    Kobzarev, I.Yu.; Martemyanov, B.V.; Okun, L.B.; Schepkin, M.G.

    1981-01-01

    Sum rules for neutrino oscillations are obtained. The derivation of the general form of the s matrix for two stage process lsub(i)sup(-)→ν→lsub(k)sup(+-) (where lsub(i)sup(-)e, μ, tau, ... are initial leptons with flavor i and lsub(k)sup(+-) is final lepton) is presented. The consideration of two stage process lsub(i)sup(-)→ν→lsub(k)sup(+-) gives the possibility to take into account neutrino masses and to obtain the expressions for the oscillating cross sections. In the case of Dirac and left-handed Majorana neutrino is obtained the sum rule for the quantities 1/Vsub(K)σ(lsub(i)sup(-)→lsub(K)sup(+-)), (where Vsub(K) is a velocity of lsub(K)). In the left-handed Majorana neutrino case there is an additional antineutrino admixture leading to lsub(i)sup(-)→lsub(K)sup(+) process. Both components (neutrino and antineutrino) oscillate independently. The sums Σsub(K)1/Vsub(k)σ(lsub(i)sup(-) - lsub(K)sup(+-) then oscillate due to the presence of left-handed antineutrinos and right-handed neutrinos which do not take part in weak interactions. If right-handed currents are added sum rules analogous to considered above may be obtained. All conclusions are valid in the general case when CP is not conserved [ru

  20. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    The study of solitons in those physical systems reveals some exciting .... With the following power series expansions for g(z,t) and f(z,t): g(z,t) = εg1(z,t) + ... If nonlinearity γ (z) is also taken as a function in figure 1b, the periodic and oscillation.

  1. Low-Vibration Oscillating Compressor

    Science.gov (United States)

    Studer, P. A.

    1984-01-01

    Oscillating compressor momentum compensated: produces little vibration in its supporting structure. Compressure requires no lubrication and virtually free of wear. Compresses working fluids such as helium, nitrogen or chlorfluorocarbons for Stirling-cycle refrigeration or other purposes. Compressor includes two mutually opposed ferromagnetic pistons of same shape and mass. Electromagnetic flux links both pistons, causing magnetic attraction between them.

  2. Matter effects in neutrino oscillations

    International Nuclear Information System (INIS)

    Dass, G.V.

    1989-01-01

    After a review of the relevant aspects of neutrino oscillations for propagation in vacuum and in material media, this paper discuss the Mikheyev-Smirnov-Wolfenstein mechanism and its application to a solution of the solar neutrino puzzle. The elementary level of the talk is suitable to people not working in neutrino physics

  3. Mesino oscillation in MFV SUSY

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua [Cornell University, Department of Physics, LEPP, Ithaca, NY (United States); SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Csaki, Csaba; Grossman, Yuval; Heidenreich, Ben [Cornell University, Department of Physics, LEPP, Ithaca, NY (United States)

    2013-04-15

    R-parity violating supersymmetry in a Minimal Flavor Violation paradigm can produce same-sign dilepton signals via direct sbottom-LSP pair production. Such signals arise when the sbottom hadronizes and the resulting mesino oscillates into an antimesino. The first bounds on the sbottom mass are placed in this scenario using current LHC results. (orig.)

  4. Chimera States in Neural Oscillators

    Science.gov (United States)

    Bahar, Sonya; Glaze, Tera

    2014-03-01

    Chimera states have recently been explored both theoretically and experimentally, in various coupled nonlinear oscillators, ranging from phase-oscillator models to coupled chemical reactions. In a chimera state, both coherent and incoherent (or synchronized and desynchronized) states occur simultaneously in populations of identical oscillators. We investigate chimera behavior in a population of neural oscillators using the Huber-Braun model, a Hodgkin-Huxley-like model originally developed to characterize the temperature-dependent bursting behavior of mammalian cold receptors. One population of neurons is allowed to synchronize, with each neuron receiving input from all the others in its group (global within-group coupling). Subsequently, a second population of identical neurons is placed under an identical global within-group coupling, and the two populations are also coupled to each other (between-group coupling). For certain values of the coupling constants, the neurons in the two populations exhibit radically different synchronization behavior. We will discuss the range of chimera activity in the model, and discuss its implications for actual neural activity, such as unihemispheric sleep.

  5. Magnetron with smooth anode. Statistical theory and ordered oscillations; Magnetron a anode lisse. Theorie statistique et oscillations ordonnees

    Energy Technology Data Exchange (ETDEWEB)

    Coste, J.

    1961-03-15

    We have to investigate the equilibrium regime that appears between a hot cathode and the electronic cloud that is confined around the cathode by a magnetic field parallel to its axis. The densities being high enough to involve the effect of space charge. The challenge of the magnetron theory is to face 2 issues: first the structure of the electronic cloud in a diode submitted to a magnetic field and secondly the oscillations that are likely to appear in this cloud. In this work we have made 2 attempts to clarify the situation, we have extended the classical theory of the static charge of space through a study of its oscillation modes on one hand and on the other hand we have tackled the issue of the structure of the electronic cloud with the tool of statistics. This document is divided into 2 chapters. In the first chapter we present a static study of the magnetron in which we take a statistical approach deliberately. We give answers to the issue of the thermodynamical equilibrium of the electronic cloud and we have found a mode very close to the Brillouin mode. The statistical approach has made us discuss the boundary conditions on the cathode, it means the coupling between the cathode and the electronic cloud. In the second chapter we present the theoretical study of the oscillations in a magnetron operating in the Brillouin mode. The resonances that appear in experimental data stay difficult to explain.

  6. Collective oscillations of electrons when simulating first principles and nature of anomalous drift along the power axis

    International Nuclear Information System (INIS)

    Majorov, S.A.; Tkachev, A.N.; Yakovlenko, S.I.

    1996-01-01

    A hypothesis is proposed that a metastable supercooled state of a classic Coulomb particle system can be conditioned by a quasiresonance interaction of bound electrons with the collective oscillations of plasma electrons. This interaction is especially important when the Kepler frequency is of the order of Langmuir oscillation frequency (which takes place when the electron orbit radius is of the order of average distance between the charges). Based on the simulation it is shown that the typical time of the Coulomb particle system dipole moment oscillations appears to be of the order of the Langmuir oscillation frequency. 10 refs.; 3 figs

  7. Dipole oscillations of a Bose-Einstein condensate in the presence of defects and disorder.

    Science.gov (United States)

    Albert, M; Paul, T; Pavloff, N; Leboeuf, P

    2008-06-27

    We consider dipole oscillations of a trapped dilute Bose-Einstein condensate in the presence of a scattering potential consisting either in a localized defect or in an extended disordered potential. In both cases the breaking of superfluidity and the damping of the oscillations are shown to be related to the appearance of a nonlinear dissipative flow. At supersonic velocities the flow becomes asymptotically dissipationless.

  8. ELMy-H mode as limit cycle and chaotic oscillations in tokamak plasmas

    International Nuclear Information System (INIS)

    Itoh Sanae, I.; Itoh, Kimitaka; Fukuyama, Atsushi; Miura, Yukitoshi.

    1991-05-01

    A model of Edge Localized Modes (ELMs) in tokamak plasmas is presented. A limit cycle solution is found in the transport equation (time-dependent Ginzburg-Landau type), which a has hysteresis curve between the gradient and flux. Periodic oscillation of the particle outflux and L/H intermediate state are predicted near the L/H transition boundary. A mesophase in spatial structure appears near edge. Chaotic oscillation is also predicted. (author)

  9. Different types of bursting calcium oscillations in non-excitable cells

    International Nuclear Information System (INIS)

    Perc, Matjaz; Marhl, Marko

    2003-01-01

    In the paper different types of bursting Ca 2+ oscillations are presented. We analyse bursting behaviour in four recent mathematical models for Ca 2+ oscillations in non-excitable cells. Separately, regular, quasi-periodic, and chaotic bursting Ca 2+ oscillations are classified into several subtypes. The classification is based on the dynamics of separated fast and slow subsystems, the so-called fast-slow burster analysis. For regular bursting Ca 2+ oscillations two types of bursting are specified: Point-Point and Point-Cycle bursting. In particular, the slow passage effect, important for the Hopf-Hopf and SubHopf-SubHopf bursting subtypes, is explained by local divergence calculated for the fast subsystem. Quasi-periodic bursting Ca 2+ oscillations can be found in only one of the four studied mathematical models and appear via a homoclinic bifurcation with a homoclinic torus structure. For chaotic bursting Ca 2+ oscillations, we found that bursting patterns resulting from the period doubling root to chaos considerably differ from those appearing via intermittency and have to be treated separately. The analysis and classification of different types of bursting Ca 2+ oscillations provides better insight into mechanisms of complex intra- and intercellular Ca 2+ signalling. This improves our understanding of several important biological phenomena in cellular signalling like complex frequency-amplitude signal encoding and synchronisation of intercellular signal transduction between coupled cells in tissue

  10. On the dynamics of traveling phase-oscillators with positive and negative couplings

    International Nuclear Information System (INIS)

    Choi, Jungzae; Choi, Mooyoung; Yoon, Byunggook

    2014-01-01

    We investigate numerically the dynamics of traveling clusters in systems of phase oscillators, some of which possess positive couplings and others negative couplings. The phase distribution, speed of traveling, and average separation between clusters, as well as the order parameters for positive and negative oscillators, are computed as the ratio of the two coupling constants and the fraction of positive oscillators are varied. The dependence of the traveling speed on these parameters is obtained and is observed to fit well with the numerical data of the systems. With the help of this, we describe the conditions for the traveling state to appear in the systems with and without a periodic driving field.

  11. Collective motions of globally coupled oscillators and some probability distributions on circle

    Energy Technology Data Exchange (ETDEWEB)

    Jaćimović, Vladimir [Faculty of Natural Sciences and Mathematics, University of Montenegro, Cetinjski put, bb., 81000 Podgorica (Montenegro); Crnkić, Aladin, E-mail: aladin.crnkic@hotmail.com [Faculty of Technical Engineering, University of Bihać, Ljubijankićeva, bb., 77000 Bihać, Bosnia and Herzegovina (Bosnia and Herzegovina)

    2017-06-28

    In 2010 Kato and Jones described a new family of probability distributions on circle, obtained as Möbius transformation of von Mises distribution. We present the model demonstrating that these distributions appear naturally in study of populations of coupled oscillators. We use this opportunity to point out certain relations between Directional Statistics and collective motion of coupled oscillators. - Highlights: • We specify probability distributions on circle that arise in Kuramoto model. • We study how the mean-field coupling affects the shape of distribution of phases. • We discuss potential applications in some experiments on cell cycle. • We apply Directional Statistics to study collective dynamics of coupled oscillators.

  12. Displacement measurement using an optoelectronic oscillator with an intra-loop Michelson interferometer.

    Science.gov (United States)

    Lee, Jehyun; Park, Sooyoung; Seo, Dae Han; Yim, Sin Hyuk; Yoon, Seokchan; Cho, D

    2016-09-19

    We report on measurement of small displacements with sub-nanometer precision using an optoelectronic oscillator (OEO) with an intra-loop Michelson interferometer. In comparison with conventional homodyne and heterodyne detection methods, where displacement appears as a power change or a phase shift, respectively, in the OEO detection, the displacement produces a shift in the oscillation frequency. In comparison with typical OEO sensors, where the frequency shift is proportional to the OEO oscillation frequency in radio-frequency domain, the frequency shift in our method with an intra-loop interferometer is proportional to an optical frequency. We constructed a hybrid apparatus and compared characteristics of the OEO and heterodyne detection methods.

  13. Generalized oscillator systems and their parabosonic interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Macfarlane, A J [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics

    1994-12-31

    The Fock space description of various bosonic oscillator systems are carried out. All descriptions are based on a single creation - annihilation pair. Special attention is paid to the q-deformed Calogero-Vasiliev oscillator. 23 refs.

  14. Analytic Neutrino Oscillation Probabilities in Matter: Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Parke, Stephen J. [Fermilab; Denton, Peter B. [Copenhagen U.; Minakata, Hisakazu [Madrid, IFT

    2018-01-02

    We summarize our recent paper on neutrino oscillation probabilities in matter, explaining the importance, relevance and need for simple, highly accurate approximations to the neutrino oscillation probabilities in matter.

  15. Characterizing brain oscillations in cognition and disease

    NARCIS (Netherlands)

    Jiang, H.

    2016-01-01

    It has been suggested that neuronal oscillations play a fundamental role for shaping the functional architecture of the working brain. This thesis investigates brain oscillations in rat, human healthy population and major depressive disorder (MDD) patients. A novel measurement termed

  16. Emergence of amplitude death scenario in a network of oscillators under repulsive delay interaction

    International Nuclear Information System (INIS)

    Bera, Bidesh K.; Hens, Chittaranjan; Ghosh, Dibakar

    2016-01-01

    Highlights: • Amplitude death is observed using repulsive mean coupling. • Analytical conditions for amplitude death are derived. • Effect of asymmetry time delay coupling for death is discussed. - Abstract: We report the existence of amplitude death in a network of identical oscillators under repulsive mean coupling. Amplitude death appears in a globally coupled network of identical oscillators with instantaneous repulsive mean coupling only when the number of oscillators is more than two. We further investigate that, amplitude death may emerge even in two coupled oscillators as well as network of oscillators if we introduce delay time in the repulsive mean coupling. We have analytically derived the region of amplitude death island and find out how strength of delay controls the death regime in two coupled or a large network of coupled oscillators. We have verified our results on network of delayed Mackey–Glass systems where parameters are set in hyperchaotic regime. We have also tested our coupling approach in two paradigmatic limit cycle oscillators: Stuart–Landau and Van der Pol oscillators.

  17. Emergence of amplitude death scenario in a network of oscillators under repulsive delay interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Bidesh K., E-mail: bideshbera18@gmail.com [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108 (India); Hens, Chittaranjan, E-mail: chittaranjanhens@gmail.com [Department of Mathematics, Bar-Ilan University, Ramat Gan 52900 (Israel); Ghosh, Dibakar, E-mail: dibakar@isical.ac.in [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108 (India)

    2016-07-15

    Highlights: • Amplitude death is observed using repulsive mean coupling. • Analytical conditions for amplitude death are derived. • Effect of asymmetry time delay coupling for death is discussed. - Abstract: We report the existence of amplitude death in a network of identical oscillators under repulsive mean coupling. Amplitude death appears in a globally coupled network of identical oscillators with instantaneous repulsive mean coupling only when the number of oscillators is more than two. We further investigate that, amplitude death may emerge even in two coupled oscillators as well as network of oscillators if we introduce delay time in the repulsive mean coupling. We have analytically derived the region of amplitude death island and find out how strength of delay controls the death regime in two coupled or a large network of coupled oscillators. We have verified our results on network of delayed Mackey–Glass systems where parameters are set in hyperchaotic regime. We have also tested our coupling approach in two paradigmatic limit cycle oscillators: Stuart–Landau and Van der Pol oscillators.

  18. Free Oscillations of the Facula Node at the Stage of Slow Dissipation

    Science.gov (United States)

    Solov'ev, A. A.; Kirichek, E. A.; Efremov, V. I.

    2017-12-01

    A solar faculae having an appearance of quite long-lived magnetic nodes can perform (as well as sunspots, chromospheric filaments, coronal loops) free oscillations, i.e., they can oscillate about the stable equilibrium position as a single whole, changing quasi-periodically magnetic field averaged over the section with periods from 1 to 4 hours. Kolotkov et al. (2017) described the case in which the average magnetic field strength of the facula node considerably decreased during observations of SDO magnetograms (13 hours), and, at the same time, its oscillations acquired a specific character: the fundamental mode of free oscillations of the facula considerably increased in amplitude (by approximately two times), while the period of oscillations increased by three times. At the end of the process, the system dissipated. In this work, we present the exact solution of the equation of small-amplitude oscillations of the system with a time-variable rigidity, describing the oscillation behavior at which the elasticity of the system decreases with time, while the period and amplitude of oscillations grow.

  19. Slow oscillation amplitudes and up-state lengths relate to memory improvement.

    Directory of Open Access Journals (Sweden)

    Dominik P J Heib

    Full Text Available There is growing evidence of the active involvement of sleep in memory consolidation. Besides hippocampal sharp wave-ripple complexes and sleep spindles, slow oscillations appear to play a key role in the process of sleep-associated memory consolidation. Furthermore, slow oscillation amplitude and spectral power increase during the night after learning declarative and procedural memory tasks. However, it is unresolved whether learning-induced changes specifically alter characteristics of individual slow oscillations, such as the slow oscillation up-state length and amplitude, which are believed to be important for neuronal replay. 24 subjects (12 men aged between 20 and 30 years participated in a randomized, within-subject, multicenter study. Subjects slept on three occasions for a whole night in the sleep laboratory with full polysomnography. Whereas the first night only served for adaptation purposes, the two remaining nights were preceded by a declarative word-pair task or by a non-learning control task. Slow oscillations were detected in non-rapid eye movement sleep over electrode Fz. Results indicate positive correlations between the length of the up-state as well as the amplitude of both slow oscillation phases and changes in memory performance from pre to post sleep. We speculate that the prolonged slow oscillation up-state length might extend the timeframe for the transfer of initial hippocampal to long-term cortical memory representations, whereas the increase in slow oscillation amplitudes possibly reflects changes in the net synaptic strength of cortical networks.

  20. Two particle states, lepton mixing and oscillations

    CERN Document Server

    Kachelriess, M; Schönert, S

    2000-01-01

    Discussions of lepton mixing and oscillations consider generally only flavor oscillations of neutrinos and neglect the accompanying charged leptons. In cases of experimental interest like pion or nuclear beta decay an oscillation pattern is expected indeed only for neutrinos if only one of the two produced particles is observed. We argue that flavor oscillations of neutrinos without detecting the accompanying lepton is a peculiarity of the two-particle states $|l\

  1. A theory of generalized Bloch oscillations

    DEFF Research Database (Denmark)

    Duggen, Lars; Lew Yan Voon, L. C.; Lassen, Benny

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact...... oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics....

  2. Pile oscillator ROB-1, cooperation NPY

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, M; Markovic, V; Obradovic, D; Kocic, A; Velickovic, LJ; Jovanovic, S [Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1965-11-15

    The present paper explains the purpose of the work on reactor kinetics and separately deals with the region for which the ROB-1 reactor oscillator is constructed. The theoretical part concerns the basic principles on which the oscillator operates. the paper also discusses the details of the oscillator, the procedure for preparation and measurement, and analyzes the source of errors. In addition several examples of the use of oscillator are given. (author)

  3. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  4. Comparison of Methods for Oscillation Detection

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Trangbæk, Klaus

    2006-01-01

    This paper compares a selection of methods for detecting oscillations in control loops. The methods are tested on measurement data from a coal-fired power plant, where some oscillations are occurring. Emphasis is put on being able to detect oscillations without having a system model and without...... using process knowledge. The tested methods show potential for detecting the oscillations, however, transient components in the signals cause false detections as well, motivating usage of models in order to remove the expected signals behavior....

  5. Pile oscillator ROB-1, cooperation NPY

    International Nuclear Information System (INIS)

    Petrovic, M.; Markovic, V.; Obradovic, D.; Kocic, A.; Velickovic, LJ.; Jovanovic, S.

    1965-11-01

    The present paper explains the purpose of the work on reactor kinetics and separately deals with the region for which the ROB-1 reactor oscillator is constructed. The theoretical part concerns the basic principles on which the oscillator operates. the paper also discusses the details of the oscillator, the procedure for preparation and measurement, and analyzes the source of errors. In addition several examples of the use of oscillator are given. (author)

  6. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing; Arcak, Murat; Salama, Khaled N.

    2010-01-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  7. NOx Emission Reduction by Oscillating Combustion

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    This project focuses on a new technology that reduces NOx emissions while increasing furnace efficiency for both air- and oxygen-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.

  8. Neutrino oscillations: present status and outlook

    International Nuclear Information System (INIS)

    Schwetz, T.

    2005-01-01

    In this talk the present status of neutrino oscillations is reviewed, based on a global analysis of world neutrino oscillation data from solar, atmospheric, reactor, and accelerator neutrino experiments. Furthermore, I discuss the expected improvements in the determination of neutrino parameters by future oscillation experiments within a timescale of 10 years. (author)

  9. Neutrino oscillations in the early universe

    International Nuclear Information System (INIS)

    Enqvist, K.

    1990-01-01

    The oscillations of electron neutrinos into inert neutrinos may have resonant behaviour in the heat bath of the early Universe. It is shown that any initial neutrino asymmetry will be washed away by the oscillations. Neutrino oscillations would affect also primordial helium production, which implies stringent limits on the neutrino mixing parameters. (orig.)

  10. The supersymmetric Pegg-Barnett oscillator

    International Nuclear Information System (INIS)

    Shen, Jian Qi

    2005-01-01

    The su(n) Lie algebraic structure of the Pegg-Barnett oscillator that possesses a finite-dimensional number-state space is demonstrated. The supersymmetric generalization of the Pegg-Barnett oscillator is suggested. it is shown that such a supersymmetric Pegg-Barnett oscillator may have some potential applications, e.g., the mass spectrum of the charged leptons

  11. Three flavour oscillation interpretation of neutrino data

    Indian Academy of Sciences (India)

    To explain the atmospheric neutrino problem in terms of neutrino oscillations, ЖС¾ of about 10-¿. eV. ¾. [8] is needed whereas the neutrino oscil- lation solution to the solar neutrino problem requires ЖС¾ ~10- eV. ¾ . Hence both solar and atmospheric neutrino problems cannot be explained in terms of e ° μ oscillations.

  12. Neutrino oscillations on the way to long-baseline experiments

    CERN Document Server

    Ryabov, V A

    2003-01-01

    The motivations and physical objectives of experiments in the search for nu /sub mu / to nu /sub e/, nu /sub tau / oscillations in long- baseline accelerator neutrino beams are reviewed. Neutrino beams, detectors, and methods for detecting oscillations (detection of the disappearance of nu /sub mu /, and the appearance of nu /sub e/ and nu /sub tau /) in the current K2K (KEK to Super Kamiokande) experiment and in the MINOS (FNAL to Soudan) and OPERA (CERN to Gran Sasso) near-future experiments are discussed. Possibilities of measuring the oscillation parameters in these experiments are considered in connection with new data obtained in CHOOZ and Palo Verde reactor experiments, the solar neutrino deficit and nu /sub mu // nu /sub e/ anomaly of atmospheric neutrinos, which are observed in large-scale underground detectors, and the excess of nu /sub e/ events in the LSND experiment. Neutrino-oscillation scenarios used in models with three and four (including sterile) types of neutrino, as well as the possibility...

  13. Global plasma oscillations in electron internal transport barriers in TCV

    Energy Technology Data Exchange (ETDEWEB)

    Udintsev, V S; Sauter, O; Asp, E; Fable, E; Goodman, T P; Turri, G; Graves, J P; Zucca, C [Association Euratom-Confederation Suisse, EPFL/SB/CRPP, Station 13, CH-1015, Lausanne (Switzerland); Scarabosio, A [Max-Planck Institut fuer Plasmaphysik, IPP-EURATOM Association, Garching (Germany); Zhuang, G [Huazhong University of Science and Technology, Wuhan, Hubei (China)

    2008-12-15

    In the Tokamak a Configuration Variable (TCV) (Hofmann F et al1994 Plasma Phys. Control. Fusion 36 B277), global plasma oscillations have been discovered in fully non-inductively driven plasmas featuring electron internal transport barriers (ITB) with strong ECRH/ECCD. These oscillations are linked to the destabilization and stabilization of MHD modes near the foot of the ITB and can lead to large oscillations of the total plasma current and line-averaged density, among others. They are intrinsically related to the fact that ITBs have large pressure gradients in a region of low magnetic shear. Therefore, the ideal MHD limit is relatively low and infernal modes can be unstable. Depending on the proximity to the ideal limit, small crashes or resistive modes can appear which affect the time evolution of the discharge. Being near marginal stability, the modes can self-stabilize due to the modification of the pressure gradient and local q-profile. The plasma recovers good confinement, reverses shear and the ITB builds up, until a new MHD mode is destabilized. TCV results show that this cycling behaviour can be controlled by modifying the current density or the pressure profiles, either with Ohmic current density perturbation or by modifying the ECH/ECCD power. It is demonstrated that many observations such as q {>=} 2 sawteeth, beta collapses, minor disruptions and oscillation regimes in ITBs can be assigned to the same physics origin: the proximity to the infernal mode stability limit.

  14. Global plasma oscillations in electron internal transport barriers in TCV

    Science.gov (United States)

    Udintsev, V. S.; Sauter, O.; Asp, E.; Fable, E.; Goodman, T. P.; Turri, G.; Graves, J. P.; Scarabosio, A.; Zhuang, G.; Zucca, C.; TCV Team

    2008-12-01

    In the Tokamak à Configuration Variable (TCV) (Hofmann F et al1994 Plasma Phys. Control. Fusion 36 B277), global plasma oscillations have been discovered in fully non-inductively driven plasmas featuring electron internal transport barriers (ITB) with strong ECRH/ECCD. These oscillations are linked to the destabilization and stabilization of MHD modes near the foot of the ITB and can lead to large oscillations of the total plasma current and line-averaged density, among others. They are intrinsically related to the fact that ITBs have large pressure gradients in a region of low magnetic shear. Therefore, the ideal MHD limit is relatively low and infernal modes can be unstable. Depending on the proximity to the ideal limit, small crashes or resistive modes can appear which affect the time evolution of the discharge. Being near marginal stability, the modes can self-stabilize due to the modification of the pressure gradient and local q-profile. The plasma recovers good confinement, reverses shear and the ITB builds up, until a new MHD mode is destabilized. TCV results show that this cycling behaviour can be controlled by modifying the current density or the pressure profiles, either with Ohmic current density perturbation or by modifying the ECH/ECCD power. It is demonstrated that many observations such as q >= 2 sawteeth, beta collapses, minor disruptions and oscillation regimes in ITBs can be assigned to the same physics origin: the proximity to the infernal mode stability limit.

  15. Autonomous Voltage Oscillations in a Direct Methanol Fuel Cell

    International Nuclear Information System (INIS)

    Nogueira, Jéssica A.; Peña Arias, Ivonne K.; Hanke-Rauschenbach, Richard; Vidakovic-Koch, Tanja; Varela, Hamilton; Sundmacher, Kai

    2016-01-01

    Proton exchange membrane fuel cells fed with H_2/CO mixtures at the anode have a considerably lower performance than fuel cells fed with pure hydrogen. However, when operated in an autonomous oscillatory regime, the overall voltage loss decreases due to a self-cleaning mechanism. Another molecule, also widely used as feed in the fuel cell and susceptible to kinetic instabilities, is methanol. To the best of our knowledge, there are no reports on autonomous voltage oscillations in the direct methanol fuel cell (DMFC). The purpose of this work was to explore if such instabilities also occur in the DMFC system. Initially, half-cell experiments with a gas diffusion electrode were performed. Then, a DMFC was operated under current control and studied by means of electrochemical impedance spectroscopy. The half-cell measurements revealed that the induction period for oscillations depends on the mass transfer conditions, where on stagnant electrode the induction time was shorter than in the case of forced convection. The DMFC showed also autonomous voltage oscillations above a certain threshold current. The results obtained by electrochemical impedance spectroscopy give evidence of a negative differential resistance in the fuel cell, hitherto not described in the literature, which can be related to the appearance of oscillations during galvanostatic methanol electro-oxidation. These results open the possibility to evaluate the performance of low-temperature fuel cells fed with carbon-containing fuels under oscillatory operating conditions.

  16. Investigation on multi-frequency oscillations in InGaAs planar Gunn diode with multiple anode-cathode spacings

    Science.gov (United States)

    Li, B.; Alimi, Y.; Ma, G. L.

    2016-12-01

    Current oscillations in an AlGaAs/InGaAs/AlGaAs-based two-dimensional electron gas (2DEG)-based hetero-structure have been investigated by means of semiconductor device simulation software SILVACO, with an interest on the charge domain formation at large biases. Single-frequency oscillations are generated in planar Gunn diodes with uniform anode and cathode contacts. The oscillation frequency reduces as the applied bias voltage increases. We show that it is possible to create multiple, independent charge domains in a novel Gunn diode structure with designed multiple anode-cathode spacings. This enables simultaneous generation of multiple frequency oscillations in a single planar device, in contrast to traditional vertical Gunn diodes where only single-frequency oscillations can be achieved. More interestingly, frequency mixing in multiple-channel configured Gunn diodes appeared. This proof-of-concept opens up the possibility for realizing compact self-oscillating mixer at millimeter-wave applications.

  17. Chaotic oscillations in a low pressure two-phase natural circulation loop under low power and high inlet subcooling conditions

    International Nuclear Information System (INIS)

    Wu, C.Y.; Wang, S.B.; Pan, C.

    1996-01-01

    The oscillation characteristics of a low pressure two-phase natural circulation loop have been investigated experimentally in this study. Experimental results indicate that the characteristics of the thermal hydraulic oscillations can be periodic, with 2-5 fundamental frequencies, or chaotic, depending on the heating power and inlet subcooling. The number of fundamental frequencies of oscillation increases if the inlet subcooling is increased at a given heating power or the heating power is decreased at a given inlet subcooling; chaotic oscillations appear if the inlet subcooling is further increased and/or the heating power is further decreased. A map of the oscillation characteristics is thus established. The change in oscillation characteristics is evident from the time evolution and power spectrum of a thermal hydraulic parameter and the phase portraits of two thermal hydraulic parameters. These results reveal that a strange attractor exists in a low pressure two-phase natural circulation loop with low power and very high inlet subcooling. (orig.)

  18. Slow oscillations orchestrating fast oscillations and memory consolidation.

    Science.gov (United States)

    Mölle, Matthias; Born, Jan

    2011-01-01

    Slow-wave sleep (SWS) facilitates the consolidation of hippocampus-dependent declarative memory. Based on the standard two-stage memory model, we propose that memory consolidation during SWS represents a process of system consolidation which is orchestrated by the neocortical memory. The slow oscillations temporally group neuronal activity into up-states of strongly enhanced neuronal activity and down-states of neuronal silence. In a feed-forward efferent action, this grouping is induced not only in the neocortex but also in other structures relevant to consolidation, namely the thalamus generating 10-15Hz spindles, and the hippocampus generating sharp wave-ripples, with the latter well known to accompany a replay of newly encoded memories taking place in hippocampal circuitries. The feed-forward synchronizing effect of the slow oscillation enables the formation of spindle-ripple events where ripples and accompanying reactivated hippocampal memory information become nested into the single troughs of spindles. Spindle-ripple events thus enable reactivated memory-related hippocampal information to be fed back to neocortical networks in the excitable slow oscillation up-state where they can induce enduring plastic synaptic changes underlying the effective formation of long-term memories. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Measuring neutrino oscillation parameters using $\

    Energy Technology Data Exchange (ETDEWEB)

    Backhouse, Christopher James [Oriel College, Oxford (United Kingdom)

    2011-01-01

    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 (Δmatm2 and sin2atm). The oscillation signal consists of an energy-dependent deficit of vμ 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 vμ-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 vμ-disappearance analysis, incorporating this new estimator were: Δm2 = 2.32-0.08+0.12 x 10-3 eV2, sin 2 2θ > 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 $\\bar{v}$μ beam, yielded somewhat different best-fit parameters Δ$\\bar{m}${sup 2} = (3.36-0.40+0.46(stat.) ± 0.06(syst.)) x 10-3eV2, sin2 2$\\bar{θ}$ = 0.86-0.12_0

  20. Constraints on Oscillation Parameters from νe Appearance and νμ Disappearance in NOvA

    Science.gov (United States)

    Adamson, P.; Aliaga, L.; Ambrose, D.; Anfimov, N.; Antoshkin, A.; Arrieta-Diaz, E.; Augsten, K.; Aurisano, A.; Backhouse, C.; Baird, M.; Bambah, B. A.; Bays, K.; Behera, B.; Bending, S.; Bernstein, R.; Bhatnagar, V.; Bhuyan, B.; Bian, J.; Blackburn, T.; Bolshakova, A.; Bromberg, C.; Brown, J.; Brunetti, G.; Buchanan, N.; Butkevich, A.; Bychkov, V.; Campbell, M.; Catano-Mur, E.; Childress, S.; Choudhary, B. C.; Chowdhury, B.; Coan, T. E.; Coelho, J. A. B.; Colo, M.; Cooper, J.; Corwin, L.; Cremonesi, L.; Cronin-Hennessy, D.; Davies, G. S.; Davies, J. P.; Derwent, P. F.; Dharmapalan, R.; Ding, P.; Djurcic, Z.; Dukes, E. C.; Duyang, H.; Edayath, S.; Ehrlich, R.; Feldman, G. J.; Frank, M. J.; Gabrielyan, M.; Gallagher, H. R.; Germani, S.; Ghosh, T.; Giri, A.; Gomes, R. A.; Goodman, M. C.; Grichine, V.; Group, R.; Grover, D.; Guo, B.; Habig, A.; Hartnell, J.; Hatcher, R.; Hatzikoutelis, A.; Heller, K.; Himmel, A.; Holin, A.; Hylen, J.; Jediny, F.; Judah, M.; Kafka, G. K.; Kalra, D.; Kasahara, S. M. S.; Kasetti, S.; Keloth, R.; Kolupaeva, L.; Kotelnikov, S.; Kourbanis, I.; Kreymer, A.; Kumar, A.; Kurbanov, S.; Lang, K.; Lee, W. M.; Lin, S.; Liu, J.; Lokajicek, M.; Lozier, J.; Luchuk, S.; Maan, K.; Magill, S.; Mann, W. A.; Marshak, M. L.; Matera, K.; Matveev, V.; Méndez, D. P.; Messier, M. D.; Meyer, H.; Miao, T.; Miller, W. H.; Mishra, S. R.; Mohanta, R.; Moren, A.; Mualem, L.; Muether, M.; Mufson, S.; Murphy, R.; Musser, J.; Nelson, J. K.; Nichol, R.; Niner, E.; Norman, A.; Nosek, T.; Oksuzian, Y.; Olshevskiy, A.; Olson, T.; Paley, J.; Pandey, P.; Patterson, R. B.; Pawloski, G.; Pershey, D.; Petrova, O.; Petti, R.; Phan-Budd, S.; Plunkett, R. K.; Poling, R.; Potukuchi, B.; Principato, C.; Psihas, F.; Radovic, A.; Rameika, R. A.; Rebel, B.; Reed, B.; Rocco, D.; Rojas, P.; Ryabov, V.; Sachdev, K.; Sail, P.; Samoylov, O.; Sanchez, M. C.; Schroeter, R.; Sepulveda-Quiroz, J.; Shanahan, P.; Sheshukov, A.; Singh, J.; Singh, J.; Singh, P.; Singh, V.; Smolik, J.; Solomey, N.; Song, E.; Sousa, A.; Soustruznik, K.; Strait, M.; Suter, L.; Talaga, R. L.; Tamsett, M. C.; Tas, P.; Thayyullathil, R. B.; Thomas, J.; Tian, X.; Tognini, S. C.; Tripathi, J.; Tsaris, A.; Urheim, J.; Vahle, P.; Vasel, J.; Vinton, L.; Vold, A.; Vrba, T.; Wang, B.; Wetstein, M.; Whittington, D.; Wojcicki, S. G.; Wolcott, J.; Yadav, N.; Yang, S.; Zalesak, J.; Zamorano, B.; Zwaska, R.; NOvA Collaboration

    2017-06-01

    Results are reported from an improved measurement of νμ→νe transitions by the NOvA experiment. Using an exposure equivalent to 6.05 ×1 020 protons on target, 33 νe candidates are observed with a background of 8.2 ±0.8 (syst.). Combined with the latest NOvA νμ disappearance data and external constraints from reactor experiments on sin22 θ13, the hypothesis of inverted mass hierarchy with θ23 in the lower octant is disfavored at greater than 93% C.L. for all values of δC P.

  1. Time domain oscillating poles: Stability redefined in Memristor based Wien-oscillators

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-07-28

    Traditionally, the necessary and sufficient condition for any system to be oscillating is that its poles are located on the imaginary (jω) axis. In this paper, for the first time, we have shown that systems can oscillate with time-domain oscillating poles. The idea is verified using a Memristor based Wien oscillator. Sustained oscillations are observed without having the poles of the system fixed on the imaginary axis and the oscillating behavior of the system poles is reported. The oscillating resistance and triangular shape of FFT are also demonstrated with mathematical reasoning and simulation results to support the unusual and surprising characteristics. © 2009 IEEE.

  2. Simulations of fully deformed oscillating flux tubes

    Science.gov (United States)

    Karampelas, K.; Van Doorsselaere, T.

    2018-02-01

    Context. In recent years, a number of numerical studies have been focusing on the significance of the Kelvin-Helmholtz instability in the dynamics of oscillating coronal loops. This process enhances the transfer of energy into smaller scales, and has been connected with heating of coronal loops, when dissipation mechanisms, such as resistivity, are considered. However, the turbulent layer is expected near the outer regions of the loops. Therefore, the effects of wave heating are expected to be confined to the loop's external layers, leaving their denser inner parts without a heating mechanism. Aim. In the current work we aim to study the spatial evolution of wave heating effects from a footpoint driven standing kink wave in a coronal loop. Methods: Using the MPI-AMRVAC code, we performed ideal, three dimensional magnetohydrodynamic simulations of footpoint driven transverse oscillations of a cold, straight coronal flux tube, embedded in a hotter environment. We have also constructed forward models for our simulation using the FoMo code. Results: The developed transverse wave induced Kelvin-Helmholtz (TWIKH) rolls expand throughout the tube cross-section, and cover it entirely. This turbulence significantly alters the initial density profile, leading to a fully deformed cross section. As a consequence, the resistive and viscous heating rate both increase over the entire loop cross section. The resistive heating rate takes its maximum values near the footpoints, while the viscous heating rate at the apex. Conclusions: We conclude that even a monoperiodic driver can spread wave heating over the whole loop cross section, potentially providing a heating source in the inner loop region. Despite the loop's fully deformed structure, forward modelling still shows the structure appearing as a loop. A movie attached to Fig. 1 is available at http://https://www.aanda.org

  3. Accelerator studies of neutrino oscillations

    CERN Document Server

    Ereditato, A

    2000-01-01

    The question of whether the neutrino has a non-vanishing mass plays acrucial role in particle physics. A massive neutrino would unambiguously reveal the existence of new physics beyond the Standard Model. In addition, it could have profound implications on astrophysics and cosmology, with effects on the evolution of the Universe. Experiments aiming at direct neutrino-mass measurements based on kinematics have not been able, so far, to measure the very small neutrino mass. Indirect measurements can be performed by exploiting reactions which may only occur for massive neutrinos. Neutrino oscillation is one of those processes. The mass difference between neutrino mass-eigenstates can be inferred from a phase measurement. This feature allows for high sensitivity experiments. Neutrinos from different sources can be used to search for oscillations: solar neutrinos, neutrinos produced in the interaction of cosmic rays with the atmosphere and artificially produced neutrinos from nuclear reactors and particle accelera...

  4. Oscillators that sync and swarm.

    Science.gov (United States)

    O'Keeffe, Kevin P; Hong, Hyunsuk; Strogatz, Steven H

    2017-11-15

    Synchronization occurs in many natural and technological systems, from cardiac pacemaker cells to coupled lasers. In the synchronized state, the individual cells or lasers coordinate the timing of their oscillations, but they do not move through space. A complementary form of self-organization occurs among swarming insects, flocking birds, or schooling fish; now the individuals move through space, but without conspicuously altering their internal states. Here we explore systems in which both synchronization and swarming occur together. Specifically, we consider oscillators whose phase dynamics and spatial dynamics are coupled. We call them swarmalators, to highlight their dual character. A case study of a generalized Kuramoto model predicts five collective states as possible long-term modes of organization. These states may be observable in groups of sperm, Japanese tree frogs, colloidal suspensions of magnetic particles, and other biological and physical systems in which self-assembly and synchronization interact.

  5. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  6. Torsional oscillations of the sun

    International Nuclear Information System (INIS)

    Snodgrass, H.B.; Howard, R.; National Solar Observatory, Tucson, AZ)

    1985-01-01

    The sun's differential rotation has a cyclic pattern of change that is tightly correlated with the sunspot, or magnetic activity, cycle. This pattern can be described as a torsional oscillation, in which the solar rotation is periodically sped up or slowed down in certain zones of latitude while elsewhere the rotation remains essentially steady. The zones of anomalous rotation move on the sun in wavelike fashion, keeping pace with and flanking the zones of magnetic activity. It is uncertain whether this torsional oscillation is a globally coherent ringing of the sun or whether it is a local pattern caused by and causing local changes in the magnetic fields. In either case, it may be an important link in the connection between the rotation and the cycle that is widely believed to exist but is not yet understood. 46 references

  7. Cubication of conservative nonlinear oscillators

    International Nuclear Information System (INIS)

    Belendez, Augusto; Alvarez, Mariela L; Fernandez, Elena; Pascual, Inmaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear and cubic terms depend on the initial amplitude, A, while in a Taylor expansion of the restoring force these coefficients are independent of A. The replacement of the original nonlinear equation by an approximate Duffing equation allows us to obtain an approximate frequency-amplitude relation as a function of the complete elliptic integral of the first kind. Some conservative nonlinear oscillators are analysed to illustrate the usefulness and effectiveness of this scheme.

  8. Coding of Information in Limit Cycle Oscillators

    Science.gov (United States)

    Schleimer, Jan-Hendrik; Stemmler, Martin

    2009-12-01

    Starting from a general description of noisy limit cycle oscillators, we derive from the Fokker-Planck equations the linear response of the instantaneous oscillator frequency to a time-varying external force. We consider the time series of zero crossings of the oscillator’s phase and compute the mutual information between it and the driving force. A direct link is established between the phase response curve summarizing the oscillator dynamics and the ability of a limit cycle oscillator, such as a heart cell or neuron, to encode information in the timing of peaks in the oscillation.

  9. Quantum oscillations of conductivity in bismuth wires

    International Nuclear Information System (INIS)

    Condrea, Elena

    2011-01-01

    Measurements of the resistance of bismuth nanowires with several diameters and different quality reveal oscillations on the dependence of resistance under uniaxial strain at T = 4.2 K. Amplitude of oscillations is significant (38 %) at helium temperature and becomes smearing at T = 77 K. Observed oscillations originate from quantum size effect. A simple evaluation of period of oscillations allows us to identify the groups of carriers involved in transport. Calculated periods of 42.2 and 25.9 nm satisfy approximately the ratio 2:1 for two experimentally observed sets of oscillations from light and heavy electrons.

  10. Memristor-based reactance-less oscillator

    KAUST Repository

    Zidan, Mohammed A.

    2012-10-02

    The first reactance-less oscillator is introduced. By using a memristor, the oscillator can be fully implemented on-chip without the need for any capacitors or inductors, which results in an area-efficient fully integrated solution. The concept of operation of the proposed oscillator is explained and detailed mathematical analysis is introduced. Closed-form expressions for the oscillation frequency and oscillation conditions are derived. Finally, the derived equations are verified with circuit simulations showing excellent agreement. © 2011 The Institution of Engineering and Technology.

  11. Low-frequency oscillations in Hall thrusters

    International Nuclear Information System (INIS)

    Wei Li-Qiu; Han Liang; Yu Da-Ren; Guo Ning

    2015-01-01

    In this paper, we summarize the research development of low-frequency oscillations in the last few decades. The findings of physical mechanism, characteristics and stabilizing methods of low-frequency oscillations are discussed. It shows that it is unreasonable and incomplete to model an ionization region separately to analyze the physical mechanism of low-frequency oscillations. Electro-dynamics as well as the formation conditions of ionization distribution play an important role in characteristics and stabilizing of low-frequency oscillations. Understanding the physical mechanism and characteristics of low- frequency oscillations thoroughly and developing a feasible method stabilizing this instability are still important research subjects. (review)

  12. Memristor-based reactance-less oscillator

    KAUST Repository

    Zidan, Mohammed A.; Omran, Hesham; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    The first reactance-less oscillator is introduced. By using a memristor, the oscillator can be fully implemented on-chip without the need for any capacitors or inductors, which results in an area-efficient fully integrated solution. The concept of operation of the proposed oscillator is explained and detailed mathematical analysis is introduced. Closed-form expressions for the oscillation frequency and oscillation conditions are derived. Finally, the derived equations are verified with circuit simulations showing excellent agreement. © 2011 The Institution of Engineering and Technology.

  13. Harmonic oscillator on a lattice

    International Nuclear Information System (INIS)

    Ader, J.P.; Bonnier, B.; Hontebeyrie, M.; Meyers, C.

    1983-01-01

    The continuum limit of the ground state energy for the harmonic oscillator with discrete time is derived for all possible choices of the lattice derivative. The occurrence of unphysical values is shown to arise whenever the lattice laplacian is not strictly positive on its Brillouin zone. These undesirable limits can either be finite and arbitrary (multiple spectrum) or infinite (overlapping sublattices with multiple spectrum). (orig.)

  14. Multipartite entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Blasone, Massimo; Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2009-01-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  15. Multipartite entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2009-06-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  16. Invariants of collective neutrino oscillations

    International Nuclear Information System (INIS)

    Pehlivan, Y.; Balantekin, A. B.; Kajino, Toshitaka; Yoshida, Takashi

    2011-01-01

    We consider the flavor evolution of a dense neutrino gas by taking into account both vacuum oscillations and self-interactions of neutrinos. We examine the system from a many-body perspective as well as from the point of view of an effective one-body description formulated in terms of the neutrino polarization vectors. We show that, in the single angle approximation, both the many-body picture and the effective one-particle picture possess several constants of motion. We write down these constants of motion explicitly in terms of the neutrino isospin operators for the many-body case and in terms of the polarization vectors for the effective one-body case. The existence of these constants of motion is a direct consequence of the fact that the collective neutrino oscillation Hamiltonian belongs to the class of Gaudin Hamiltonians. This class of Hamiltonians also includes the (reduced) BCS pairing Hamiltonian describing superconductivity. We point out the similarity between the collective neutrino oscillation Hamiltonian and the BCS pairing Hamiltonian. The constants of motion manifest the exact solvability of the system. Borrowing the well established techniques of calculating the exact BCS spectrum, we present exact eigenstates and eigenvalues of both the many-body and the effective one-particle Hamiltonians describing the collective neutrino oscillations. For the effective one-body case, we show that spectral splits of neutrinos can be understood in terms of the adiabatic evolution of some quasiparticle degrees of freedom from a high-density region where they coincide with flavor eigenstates to the vacuum where they coincide with mass eigenstates. We write down the most general consistency equations which should be satisfied by the effective one-body eigenstates and show that they reduce to the spectral split consistency equations for the appropriate initial conditions.

  17. Oscillations and Waves in Sunspots

    Directory of Open Access Journals (Sweden)

    Elena Khomenko

    2015-11-01

    Full Text Available A magnetic field modifies the properties of waves in a complex way. Significant advances have been made recently in our understanding of the physics of sunspot waves with the help of high-resolution observations, analytical theories, as well as numerical simulations. We review the current ideas in the field, providing the most coherent picture of sunspot oscillations as by present understanding.

  18. Automatic oscillator frequency control system

    Science.gov (United States)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  19. Micro-machined resonator oscillator

    Science.gov (United States)

    Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

    1994-01-01

    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.

  20. Drifting oscillations in axion monodromy

    Energy Technology Data Exchange (ETDEWEB)

    Flauger, Raphael [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); McAllister, Liam [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Silverstein, Eva [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States); Westphal, Alexander, E-mail: flauger@physics.ucsd.edu, E-mail: mcallister@cornell.edu, E-mail: evas@stanford.edu, E-mail: alexander.westphal@desy.de [Theory Group, Deutsches Elektronen-Synchrotron DESY, D-22603 Hamburg (Germany)

    2017-10-01

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  1. Neutrino Oscillation Experiment at JHF

    CERN Multimedia

    2002-01-01

    T2K is a long baseline neutrino experiment designed to investigate how neutrinos change from one flavor to another as they travel (neutrino oscillations). An intense beam of muon neutrinos is generated at the J-PARC nuclear physics site on the East coast of Japan and directed across the country to the Super-Kamiokande neutrino detector in the mountains of western Japan. The beam is measured once before it leaves the J-PARC site, using the near detector ND280, and again at Super-K, 295 km away: the change in the measured intensity and composition of the beam is used to provide information on the properties of neutrinos. The high intensity neutrino beam is produced in an off-axis configuration. The peak neutrino energy is tuned to the oscillation maximum of ∼ 0.6 GeV to maximize the sensitivity to neutrino oscillations. The science goals of T2K can be summarized as follows: •\tsearch for CP violation in the neutrino sector •\tdiscovery of νμ → νe ( i.e. the confirmation that θ13 > 0 ) •\tprecision ...

  2. Superconducting low-noise oscillator

    International Nuclear Information System (INIS)

    Riebman, L.

    1992-01-01

    This patent describes a cryogenic oscillator having low phase noise and low noise. It comprises resonant circuit means formed of superconducting material for generating a signal at a desired frequency; linear amplifier means electrically connected to the resonant circuit means at first and second locations thereon; limiter means electrically connected to the resonant circuit means at a third location thereon; and buffer amplifier means for applying the signal generated by the resonant circuit means to a load and electrically connected to the resonant circuit means at a fourth location thereon. This patent also describes a method of minimizing phase noise and 1/f noise in an oscillator circuit of the type having a resonant circuit driving a load and at least a linear amplifier connected to the resonant circuit defining a closed loop having a loop gain greater than unity, and having a limiter for stabilizing the oscillator. It comprises connecting between the resonant circuit and the load a buffer amplifier and connecting the linear amplifier and the buffer amplifier to the resonant circuit

  3. Boltzmann map for quantum oscillators

    International Nuclear Information System (INIS)

    Streater, R.F.

    1987-01-01

    The authors define a map tau on the space of quasifree states of the CCR or CAR of more than one harmonic oscillator which increases entropy except at fixed points of tau. The map tau is the composition of a double stochastic map T*, and the quasifree reduction Q. Under mixing conditions on T, iterates of tau take any initial state to the Gibbs states, provided that the oscillator frequencies are mutually rational. They give an example of a system with three degrees of freedom with energies omega 1 , omega 2 , and omega 3 mutually irrational, but obeying a relation n 1 omega 1 + n 2 omega 2 = n 3 omega 3 , n/sub i/epsilon Z. The iterated Boltzmann map converges from an initial state rho to independent Gibbs states of the three oscillators at betas (inverse temperatures) β 1 , β 2 , β 3 obeying the equation n 1 omega 1 β 1 + n 2 omega 3 β 1 number. The equilibrium state can be rewritten as a grand canonical state. They show that for two, three, or four fermions we can get the usual rate equations as a special case

  4. Neutrino Oscillations:. a Phenomenological Approach

    Science.gov (United States)

    Fogli, G. L.; Lisi, E.; Marrone, A.; Palazzo, A.; Rotunno, A. M.; Montanino, D.

    We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

  5. Drifting oscillations in axion monodromy

    International Nuclear Information System (INIS)

    Flauger, Raphael; Westphal, Alexander

    2014-12-01

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  6. Semantic attributes for people's appearance description: an appearance modality for video surveillance applications

    Science.gov (United States)

    Frikha, Mayssa; Fendri, Emna; Hammami, Mohamed

    2017-09-01

    Using semantic attributes such as gender, clothes, and accessories to describe people's appearance is an appealing modeling method for video surveillance applications. We proposed a midlevel appearance signature based on extracting a list of nameable semantic attributes describing the body in uncontrolled acquisition conditions. Conventional approaches extract the same set of low-level features to learn the semantic classifiers uniformly. Their critical limitation is the inability to capture the dominant visual characteristics for each trait separately. The proposed approach consists of extracting low-level features in an attribute-adaptive way by automatically selecting the most relevant features for each attribute separately. Furthermore, relying on a small training-dataset would easily lead to poor performance due to the large intraclass and interclass variations. We annotated large scale people images collected from different person reidentification benchmarks covering a large attribute sample and reflecting the challenges of uncontrolled acquisition conditions. These annotations were gathered into an appearance semantic attribute dataset that contains 3590 images annotated with 14 attributes. Various experiments prove that carefully designed features for learning the visual characteristics for an attribute provide an improvement of the correct classification accuracy and a reduction of both spatial and temporal complexities against state-of-the-art approaches.

  7. Nonlinearity induced synchronization enhancement in mechanical oscillators

    Science.gov (United States)

    Czaplewski, David A.; Lopez, Omar; Guest, Jeffrey R.; Antonio, Dario; Arroyo, Sebastian I.; Zanette, Damian H.

    2018-05-08

    An autonomous oscillator synchronizes to an external harmonic force only when the forcing frequency lies within a certain interval, known as the synchronization range, around the oscillator's natural frequency. Under ordinary conditions, the width of the synchronization range decreases when the oscillation amplitude grows, which constrains synchronized motion of micro- and nano-mechanical resonators to narrow frequency and amplitude bounds. The present invention shows that nonlinearity in the oscillator can be exploited to manifest a regime where the synchronization range increases with an increasing oscillation amplitude. The present invention shows that nonlinearities in specific configurations of oscillator systems, as described herein, are the key determinants of the effect. The present invention presents a new configuration and operation regime that enhances the synchronization of micro- and nano-mechanical oscillators by capitalizing on their intrinsic nonlinear dynamics.

  8. Dysrhythmias of the respiratory oscillator

    Science.gov (United States)

    Paydarfar, David; Buerkel, Daniel M.

    1995-03-01

    Breathing is regulated by a central neural oscillator that produces rhythmic output to the respiratory muscles. Pathological disturbances in rhythm (dysrhythmias) are observed in the breathing pattern of children and adults with neurological and cardiopulmonary diseases. The mechanisms responsible for genesis of respiratory dysrhythmias are poorly understood. The present studies take a novel approach to this problem. The basic postulate is that the rhythm of the respiratory oscillator can be altered by a variety of stimuli. When the oscillator recovers its rhythm after such perturbations, its phase may be reset relative to the original rhythm. The amount of phase resetting is dependent upon stimulus parameters and the level of respiratory drive. The long-range hypothesis is that respiratory dysrhythmias can be induced by stimuli that impinge upon or arise within the respiratory oscillator with certain combinations of strength and timing relative to the respiratory cycle. Animal studies were performed in anesthetized or decerebrate preparations. Neural respiratory rhythmicity is represented by phrenic nerve activity, allowing use of open-loop experimental conditions which avoid negative chemical feedback associated with changes in ventilation. In animal experiments, respiratory dysrhythmias can be induced by stimuli having specific combinations of strength and timing. Newborn animals readily exhibit spontaneous dysrhythmias which become more prominent at lower respiratory drives. In human subjects, swallowing was studied as a physiological perturbation of respiratory rhythm, causing a pattern of phase resetting that is characterized topologically as type 0. Computational studies of the Bonhoeffer-van der Pol (BvP) equations, whose qualitative behavior is representative of many excitable systems, supports a unified interpretation of these experimental findings. Rhythmicity is observed when the BvP model exhibits recurrent periods of excitation alternating with

  9. Sawtooth oscillations as MHD relaxation process in a plasma

    International Nuclear Information System (INIS)

    Yoshida, Zensho; Inoue, Nobuyuki; Ogawa, Yuichi

    1992-01-01

    The sawtooth oscillation in a tokamak plasma is a spontaneous relaxation process accompanying global instabilities which behave to reduce the internal magnetic energy. This phenomenon has a similarity to the MHD relaxation processes in Reversed Field Pinch (RFP) and Ultra Low Q (ULQ) plasmas. The self-stabilizing effect of instabilities with m (poloidal mode number) = 1 results in an increase in the central safety factor q(0). Nonlinear dynamics of m = 1 instabilities has been discussed both for global and local modes. The latter appears when a pitch minimum exists in the plasma, and is relevant to the compound sawtooth oscillation. The MHD relaxation is a restructuring process of the plasma current profile that is competitive with the resistive diffusion. (author)

  10. Status and oscillation results of the OPERA experiment

    International Nuclear Information System (INIS)

    Brunet, F.

    2014-01-01

    The OPERA experiment, placed 730 km downstream the CERN neutrino beam to Gran Sasso (CNGS) in the LNGS underground laboratory, is designed to measure muon-neutrino to tau-neutrino oscillations in a direct appearance mode. The hybrid apparatus consists of an emulsion/lead target complemented by electronic detectors. Due to the target structure made of thin lead plates, OPERA is able to detect electromagnetic showers, allowing searches for tau electronic decays and for oscillations from muon-neutrino to electron-neutrino. The experimental set-up and associated facilities used to extract data recorded in the emulsion will be described, with the special procedures aimed at locating interaction vertices and detect short decay topologies. OPERA is taking data since 2008. A first nu-tau interaction candidate was already published in 2010. New results with increased statistics will be presented. In particular, an overview of the studies related to electrons will be shown. (author)

  11. Partially coherent twisted states in arrays of coupled phase oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Omel' chenko, Oleh E.; Wolfrum, Matthias [Weierstrass Institute, Mohrenstrasse 39, 10117 Berlin (Germany); Laing, Carlo R. [INMS, Massey University, Private Bag 102-904 NSMC, Auckland (New Zealand)

    2014-06-15

    We consider a one-dimensional array of phase oscillators with non-local coupling and a Lorentzian distribution of natural frequencies. The primary objects of interest are partially coherent states that are uniformly “twisted” in space. To analyze these, we take the continuum limit, perform an Ott/Antonsen reduction, integrate over the natural frequencies, and study the resulting spatio-temporal system on an unbounded domain. We show that these twisted states and their stability can be calculated explicitly. We find that stable twisted states with different wave numbers appear for increasing coupling strength in the well-known Eckhaus scenario. Simulations of finite arrays of oscillators show good agreement with results of the analysis of the infinite system.

  12. Partially coherent twisted states in arrays of coupled phase oscillators

    International Nuclear Information System (INIS)

    Omel'chenko, Oleh E.; Wolfrum, Matthias; Laing, Carlo R.

    2014-01-01

    We consider a one-dimensional array of phase oscillators with non-local coupling and a Lorentzian distribution of natural frequencies. The primary objects of interest are partially coherent states that are uniformly “twisted” in space. To analyze these, we take the continuum limit, perform an Ott/Antonsen reduction, integrate over the natural frequencies, and study the resulting spatio-temporal system on an unbounded domain. We show that these twisted states and their stability can be calculated explicitly. We find that stable twisted states with different wave numbers appear for increasing coupling strength in the well-known Eckhaus scenario. Simulations of finite arrays of oscillators show good agreement with results of the analysis of the infinite system

  13. Baryon acoustic oscillation intensity mapping of dark energy.

    Science.gov (United States)

    Chang, Tzu-Ching; Pen, Ue-Li; Peterson, Jeffrey B; McDonald, Patrick

    2008-03-07

    The expansion of the Universe appears to be accelerating, and the mysterious antigravity agent of this acceleration has been called "dark energy." To measure the dynamics of dark energy, baryon acoustic oscillations (BAO) can be used. Previous discussions of the BAO dark energy test have focused on direct measurements of redshifts of as many as 10(9) individual galaxies, by observing the 21 cm line or by detecting optical emission. Here we show how the study of acoustic oscillation in the 21 cm brightness can be accomplished by economical three-dimensional intensity mapping. If our estimates gain acceptance they may be the starting point for a new class of dark energy experiments dedicated to large angular scale mapping of the radio sky, shedding light on dark energy.

  14. Separation control with fluidic oscillators in water

    Science.gov (United States)

    Schmidt, H.-J.; Woszidlo, R.; Nayeri, C. N.; Paschereit, C. O.

    2017-08-01

    The present study assesses the applicability of fluidic oscillators for separation control in water. The first part of this work evaluates the properties of the fluidic oscillators including frequency, cavitation effects, and exerted thrust. Derived from the governing internal dynamics, the oscillation frequency is found to scale directly with the jet's exit velocity and the size of the fluidic oscillator independent of the working fluid. Frequency data from various experiments collapse onto a single curve. The occurrence of cavitation is examined by visual inspection and hydrophone measurements. The oscillation frequency is not affected by cavitation because it does not occur inside the oscillators. The spectral information obtained with the hydrophone provide a reliable indicator for the onset of cavitation at the exit. The performance of the fluidic oscillators for separation control on a bluff body does not seem to be affected by the presence of cavitation. The thrust exerted by an array of fluidic oscillators with water as the working fluid is measured to be even larger than theoretically estimated values. The second part of the presented work compares the performance of fluidic oscillators for separation control in water with previous results in air. The array of fluidic oscillators is installed into the rear end of a bluff body model. The drag improvements based on force balance measurements agree well with previous wind tunnel experiments on the same model. The flow field is examined by pressure measurements and with particle image velocimetry. Similar performance and flow field characteristics are observed in both water and air.

  15. Analysis of the D+ --> K- pi+ e+ nu_e decay channel

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /Bari U.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Stanford U., Phys. Dept.

    2011-08-12

    Using 347.5 fb{sup -1} of data recorded by the BABAR detector at the PEP-II electron-positron collider, 244 x 10{sup 3} signal events for the D{sup +} {yields} K{sup -}{pi}{sup +}e{sup +}{nu}{sub e} decay channel are analyzed. This decay mode is dominated by the {bar K}*(892){sup 0} contribution. We determine the {bar K}*(892){sup 0} parameters: m{sub K*(892){sup 0}} = (895.4{+-}0.2{+-}0.2) MeV/c{sup 2}, {Lambda}{sub K*(892){sup 0}}{sup 0} = (46.5{+-}0.3{+-}0.2) MeV/c{sup 2} and the Blatt-Weisskopf parameter r{sub BW} = 2.1{+-}0.5{+-}0.5 (GeV/c){sup -1} where the first uncertainty comes from statistics and the second from systematic uncertainties. We also measure the parameters defining the corresponding hadronic form factors at q{sup 2} = 0 (r{sub V} = V(0)/A{sub 1}(0) = 1.463{+-}0.017{+-}0.031, r{sup 2} = A{sub 2}(0)/A{sub 1}(0) = 0.801{+-}0.020{+-}0.020) and the value of the axial-vector pole mass parameterizing the q{sup 2} variation of A{sub 1} and A{sub 2}: m{sub A} = (2.63{+-}0.10{+-}0.13) GeV/c{sup 2}. The S-wave fraction is equal to (5.79{+-}0.16{+-}0.15)%. Other signal components correspond to fractions below 1%. Using the D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} channel as a normalization, we measure the D{sup +} semileptonic branching fraction: {Beta}(D{sup +} {yields} K{sup -}{pi}{sup +}e{sup +}{nu}{sub e}) = (4.00 {+-} 0.03 {+-} 0.04 {+-} 0.09) x 10{sup -2} where the third uncertainty comes from external inputs. We then obtain the value of the hadronic form factor A{sub 1} at q{sup 2} = 0: A{sub 1}(0) = 0.6200 {+-} 0.0056 {+-} 0.0065 {+-} 0.0071. Fixing the P-wave parameters we measure the phase of the S-wave for several values of the K{pi} mass. These results confirm those obtained with K{pi} production at small momentum transfer in fixed target experiments.

  16. Dependence of oscillational instabilities on the amplitude of the acoustic wave in single-axis levitators

    DEFF Research Database (Denmark)

    Orozco-Santillán, Arturo; Ruiz-Boullosa, Ricardo; Cutanda Henríquez, Vicente

    2007-01-01

    It is well known that acoustic waves exert forces on a boundary with which they interact; these forces can be so intense that they can compensate for the weight of small objects up to a few grams. In this way, it is possible to maintain solid or liquid samples levitating in a fluid, avoiding...... the use of containers, which may be undesirable for certain applications. Moreover, small samples can be manipulated by means of acoustic waves. In this paper, we report a study on the oscillational instabilities that can appear on a levitated solid sphere in single-axis acoustic devices. A theory...... proportional to the oscillation frequency of the levitated sample. We also present experimental results that show that the oscillational instabilities can be reduced if the amplitude of the acoustic wave is increased; as a result, stable conditions can be obtained where the oscillations of the sphere...

  17. Clusters in nonsmooth oscillator networks

    Science.gov (United States)

    Nicks, Rachel; Chambon, Lucie; Coombes, Stephen

    2018-03-01

    For coupled oscillator networks with Laplacian coupling, the master stability function (MSF) has proven a particularly powerful tool for assessing the stability of the synchronous state. Using tools from group theory, this approach has recently been extended to treat more general cluster states. However, the MSF and its generalizations require the determination of a set of Floquet multipliers from variational equations obtained by linearization around a periodic orbit. Since closed form solutions for periodic orbits are invariably hard to come by, the framework is often explored using numerical techniques. Here, we show that further insight into network dynamics can be obtained by focusing on piecewise linear (PWL) oscillator models. Not only do these allow for the explicit construction of periodic orbits, their variational analysis can also be explicitly performed. The price for adopting such nonsmooth systems is that many of the notions from smooth dynamical systems, and in particular linear stability, need to be modified to take into account possible jumps in the components of Jacobians. This is naturally accommodated with the use of saltation matrices. By augmenting the variational approach for studying smooth dynamical systems with such matrices we show that, for a wide variety of networks that have been used as models of biological systems, cluster states can be explicitly investigated. By way of illustration, we analyze an integrate-and-fire network model with event-driven synaptic coupling as well as a diffusively coupled network built from planar PWL nodes, including a reduction of the popular Morris-Lecar neuron model. We use these examples to emphasize that the stability of network cluster states can depend as much on the choice of single node dynamics as it does on the form of network structural connectivity. Importantly, the procedure that we present here, for understanding cluster synchronization in networks, is valid for a wide variety of systems in

  18. Modeling of Coupled Chaotic Oscillators

    International Nuclear Information System (INIS)

    Lai, Y.; Grebogi, C.

    1999-01-01

    Chaotic dynamics may impose severe limits to deterministic modeling by dynamical equations of natural systems. We give theoretical argument that severe modeling difficulties may occur for high-dimensional chaotic systems in the sense that no model is able to produce reasonably long solutions that are realized by nature. We make these ideas concrete by investigating systems of coupled chaotic oscillators. They arise in many situations of physical and biological interests, and they also arise from discretization of nonlinear partial differential equations. copyright 1999 The American Physical Society

  19. Magnus approximation in neutrino oscillations

    International Nuclear Information System (INIS)

    Acero, Mario A; Aguilar-Arevalo, Alexis A; D'Olivo, J C

    2011-01-01

    Oscillations between active and sterile neutrinos remain as an open possibility to explain some anomalous experimental observations. In a four-neutrino (three active plus one sterile) mixing scheme, we use the Magnus expansion of the evolution operator to study the evolution of neutrino flavor amplitudes within the Earth. We apply this formalism to calculate the transition probabilities from active to sterile neutrinos with energies of the order of a few GeV, taking into account the matter effect for a varying terrestrial density.

  20. Waves and Oscillations in Plasmas

    CERN Document Server

    Pecseli, Hans L

    2012-01-01

    The result of more than 15 years of lectures in plasma sciences presented at universities in Denmark, Norway, and the United States, Waves and Oscillations in Plasmas addresses central issues in modern plasma sciences. The book covers fluid models as well as kinetic plasma models, including a detailed discussion of, for instance, collisionless Landau damping. Offering a clear separation of linear and nonlinear models, the book can be tailored for readers of varying levels of expertise.Designed to provide basic training in linear as well as nonlinear plasma dynamics, and practical in areas as d

  1. Wave Physics Oscillations - Solitons - Chaos

    CERN Document Server

    Nettel, Stephen

    2009-01-01

    This textbook is intended for those second year undergraduates in science and engineering who will later need an understanding of electromagnetic theory and quantum mechanics. The classical physics of oscillations and waves is developed at a more advanced level than has been customary for the second year, providing a basis for the quantum mechanics that follows. In this new edition the Green's function is explained, reinforcing the integration of quantum mechanics with classical physics. The text may also form the basis of an "introduction to theoretical physics" for physics majors. The concluding chapters give special attention to topics in current wave physics: nonlinear waves, solitons, and chaotic behavior.

  2. Coupled oscillators with parity-time symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Tsoy, Eduard N., E-mail: etsoy@uzsci.net

    2017-02-05

    Different models of coupled oscillators with parity-time (PT) symmetry are studied. Hamiltonian functions for two and three linear oscillators coupled via coordinates and accelerations are derived. Regions of stable dynamics for two coupled oscillators are obtained. It is found that in some cases, an increase of the gain-loss parameter can stabilize the system. A family of Hamiltonians for two coupled nonlinear oscillators with PT-symmetry is obtained. An extension to high-dimensional PT-symmetric systems is discussed. - Highlights: • A generalization of a Hamiltonian system of linear coupled oscillators with the parity-time (PT) symmetry is suggested. • It is found that an increase of the gain-loss parameter can stabilize the system. • A family of Hamiltonian functions for two coupled nonlinear oscillators with PT-symmetry is obtained.

  3. Phase noise and frequency stability in oscillators

    CERN Document Server

    Rubiola, Enrico

    2009-01-01

    Presenting a comprehensive account of oscillator phase noise and frequency stability, this practical text is both mathematically rigorous and accessible. An in-depth treatment of the noise mechanism is given, describing the oscillator as a physical system, and showing that simple general laws govern the stability of a large variety of oscillators differing in technology and frequency range. Inevitably, special attention is given to amplifiers, resonators, delay lines, feedback, and flicker (1/f) noise. The reverse engineering of oscillators based on phase-noise spectra is also covered, and end-of-chapter exercises are given. Uniquely, numerous practical examples are presented, including case studies taken from laboratory prototypes and commercial oscillators, which allow the oscillator internal design to be understood by analyzing its phase-noise spectrum. Based on tutorials given by the author at the Jet Propulsion Laboratory, international IEEE meetings, and in industry, this is a useful reference for acade...

  4. Driven, autoresonant three-oscillator interactions

    International Nuclear Information System (INIS)

    Yaakobi, O.; Friedland, L.; Henis, Z.

    2007-01-01

    An efficient control scheme of resonant three-oscillator interactions using an external chirped frequency drive is suggested. The approach is based on formation of a double phase-locked (autoresonant) state in the system, as the driving oscillation passes linear resonance with one of the interacting oscillators. When doubly phase locked, the amplitudes of the oscillators increase with time in proportion to the driving frequency deviation from the linear resonance. The stability of this phase-locked state and the effects of dissipation and of the initial three-oscillator frequency mismatch on the autoresonance are analyzed. The associated autoresonance threshold phenomenon in the driving amplitude is also discussed. In contrast to other nonlinear systems, driven, autoresonant three-oscillator excitations are independent of the sign of the driving frequency chirp rate

  5. Lepton asymmetry and neutrino oscillations interplay

    Energy Technology Data Exchange (ETDEWEB)

    Kirilova, Daniela, E-mail: dani@astro.bas.bg [Bulgarian Academy of Sciences, Institute of Astronomy and NAO (Bulgaria)

    2013-03-15

    We discuss the interplay between lepton asymmetry L and {nu} oscillations in the early Universe. Neutrino oscillations may suppress or enhance previously existing L. On the other hand L is capable to suppress or enhance neutrino oscillations. The mechanism of L enhancement in MSW resonant {nu} oscillations in the early Universe is numerically analyzed. L cosmological effects through {nu} oscillations are discussed. We discuss how L may change the cosmological BBN constraints on neutrino and show that BBN model with {nu}{sub e}{r_reversible}{nu}{sub s} oscillations is extremely sensitive to L - it allows to obtain the most stringent constraints on L value. We discuss also the cosmological role of active-sterile {nu} mixing and L in connection with the indications about additional relativistic density in the early Universe, pointed out by BBN, CMB and LSS data and the analysis of global {nu} data.

  6. Observation of Electron Neutrino Appearance in the NuMI Beam with the NOvA Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Niner, Evan David [Indiana Univ., Bloomington, IN (United States)

    2015-01-01

    NOvA is a long-baseline neutrino oscillation experiment that uses two functionally identical detectors separated by 810 kilometers at locations 14 milliradians off-axis from the NuMI muon neutrino beam at Fermilab. At these locations the beam energy peaks at 2 GeV. This baseline is the longest in the world for an accelerator-based neutrino oscillation experiment, which enhances the sensitivity to the neutrino mass ordering. The experiment studies oscillations of the muon neutrino and anti-neutrino beam that is produced. Both detectors completed commissioning in the summer of 2014 and continue to collect data. One of the primary physics goals of the experiment is the measurement of electron neutrino appearance in the muon neutrino beam which yields measurements of the oscillation parameters sin213, δ , and the neutrino mass ordering within the standard model of neutrino oscillations. This thesis presents the analysis of data collected between February 2014 and May 2015, corresponding to 3.52 X 1020 protons-on-target. In this first analysis NOvA recorded 6 electron neutrino candidates, which is a 3.3σ observation of electron neutrino appearance. The T2K experiment performs the same measurement on a baseline of 295 kilometers and has a 1 σ preference for the normal mass ordering over the inverted ordering over the phase space of the CP violating parameter δ, which is also weakly seen in the NOvA result. By the summer of 2016 NOvA will triple its statistics due to increased beam power and a completed detector. If electron neutrinos continue to be observed at the current rate NOvA will be able to establish a mass ordering preference at a similar confidence level to T2K.

  7. A Survey on Forced Oscillations in Power System

    OpenAIRE

    Ghorbaniparvar, Mohammadreza

    2016-01-01

    Oscillations in a power system can be categorized into free oscillations and forced oscillations. Many algorithms have been developed to estimate the modes of free oscillations in a power system. Recently, forced oscillations caught many attentions. Techniques are proposed to detect forced oscillations and locate their sources. In addition, forced oscillations may have negative impact on the estimation of mode and mode-shape if they are not properly accounted for. To improve the power system ...

  8. Phase-locked Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1991-01-01

    Detailed experimental characterization of the phase-locking at both DC and at microwave frequencies is presented for two closely spaced Josephson soliton (fluxon) oscillators. In the phase-locked state, the radiated microwave power exhibited an effective gain. With one common bias source......, a frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. The interacting soliton oscillators were modeled by two inductively coupled nonlinear transmission lines...

  9. Chimera States in Mechanical Oscillator Networks

    OpenAIRE

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

    2013-01-01

    The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature uses to orchestrate essential processes of life, such as the beating of the heart. Although it was long thought that synchrony and disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years have revealed the intriguing possibility of “chimera states,” in which the symmetry of the oscillator population is broken into...

  10. Oscillations of neutral B mesons systems

    CERN Document Server

    Boucrot, J.

    1999-01-01

    The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\\bd$ meson oscillation frequency is $\\dmd = 0.471 \\pm 0.016 \\ps$ and the lower limit on the $\\bs$ oscillation frequency is

  11. Recent Progress in Silicon Mems Oscillators

    Science.gov (United States)

    2008-12-01

    MEMS oscillator. As shown, a MEMS resonator is connected to an IC. The reference oscillator, which is basically a transimpedance amplifier ...small size), and (3) DC bias voltage required to operate the resonators. As a result, instead of Colpitts or Pierce architecture, a transimpedence ... amplifier is typically used for sustain the oscillation. The frequency of the resonators is determined by both material properties and geometry of

  12. Cyanohydrin reactions enhance glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here......: a) by reducing [ACAx] relative to oscillation amplitude, b) by targeting multiple intracellular carbonyl compounds during fermentation, and c) by acting as a phase resetting stimulus....

  13. Electrochemical Oscillation of Vanadium Ions in Anolyte

    Directory of Open Access Journals (Sweden)

    Hao Peng

    2017-08-01

    Full Text Available Periodic electrochemical oscillation of the anolyte was reported for the first time in a simulated charging process of the vanadium redox flow batteries. The electrochemical oscillation could be explained in terms of the competition between the growth and the chemical dissolution of V2O5 film. Also, the oscillation phenomenon was possible to regular extra power consumption. The results of this paper might enable new methods to improve the charge efficiency and energy saving for vanadium redox flow batteries.

  14. Electron plasma oscillations at arbitrary Debye lengths

    International Nuclear Information System (INIS)

    Lehnert, B.

    1990-12-01

    A solution is presented for electron plasma oscillation in a thermalized homogeneous plasma, at arbitrary ratios between the Debye length λ D and the perturbation wave length λ. The limit λ D D >> λ corresponds to the free-streaming limit of strong kinetic phase-mixing due to large particle excursions. A strong large Debye distance (LDD) effect already appears when λ D > approx λ. The initial amplitude of the fluid-like contribution to the macroscopic density perturbation then becomes small as compared to the contribution from the free-streaming part. As a consequence, only a small fraction of the density perturbation remains after a limited number of kinetic damping times of the free-streaming part. The analysis further shows that a representation in terms of normal model of the form exp(-iωt) leads to amplitude factors of these modes which are related to each other and which depend on the combined free-streaming and fluid behaviour of the plasma. Consequently, these modes are coupled and cannot be treated as being independent of each other. (au)

  15. Fractional Josephson vortices: oscillating macroscopic spins

    Energy Technology Data Exchange (ETDEWEB)

    Gaber, T.; Buckenmaier, K.; Koelle, D.; Kleiner, R.; Goldobin, E. [Universitaet Tuebingen, Physikalisches Institut - Experimentalphysik II, Tuebingen (Germany)

    2007-11-15

    Fractional Josephson vortices carry a magnetic flux {phi}, which is a fraction of the magnetic flux quantum {phi}{sub 0}{approx}2.07 x 10{sup -15} Wb. We consider a fractional vortex which spontaneously appears at a phase discontinuity. Its properties are very different from the properties of the usual integer fluxon. In particular, a fractional vortex is pinned and may have one of two possible polarities - just like a usual spin 1/2 particle. The fractional vortex may also oscillate around its equilibrium position with an eigenfrequency which is expected to be within the Josephson plasma gap. Using microwave spectroscopy, we investigate the dependence of the eigenfrequency of a fractional Josephson vortex on its magnetic flux {phi} and on the bias current. The experimental results are in good agreement with theoretical predictions. Positive result of this experiment is a cornerstone for further investigation of more complex fractional vortex systems such as fractional vortex molecules and tunable bandgap materials. (orig.)

  16. Cardiogenic oscillation induced ventilator autotriggering

    Directory of Open Access Journals (Sweden)

    Narender Kaloria

    2015-01-01

    Full Text Available Cardiogenic oscillation during mechanical ventilation can auto-trigger the ventilator resembling patient initiated breadth. This gives a false sense of intact respiratory drive and determination brain death, even if other tests are positive, is not appropriate in such a situation. It will prolong the ICU stay and confound the brain-death determination. In this case report, we describe a 35 year old man who was brought to the hospital after many hours of critical delay following multiple gun shot injuries. The patient suffered a cardiac arrest while on the way from another hospital. After an emergency laparotomy, patient was shifted to Intensive Care Unit (ICU with Glasgow Coma Scale (GCS score of E1VTM1 and was mechanically ventilated. Despite absence of brainstem reflexes, the ventilator continued to be triggered on continuous positive airway pressure (CPAP mode and the patient maintained normal oxygen saturation and acceptable levels of carbon dioxide. An apnoea test confirmed absent respiratory drive. Ventilatory waveform graph analysis, revealed cardiogenic oscillation as the cause for autotrigerring.

  17. Energy measurements from betatron oscillations

    International Nuclear Information System (INIS)

    Himel, T.; Thompson, K.

    1989-03-01

    In the Stanford Linear Collider the electron beam is accelerated from 1--50 GeV in a distance of 3 km. The energy is measured and corrected at the end with an energy feedback loop. There are no bends within the linear accelerator itself, so no intermediate energy measurements are made. Errors in the energy profile due to mis-phasing of the rf, or due to calibration errors in the klystrons' rf outputs are difficult to detect. As the total betatron phase advance down the accelerator is about 30 /times/ 2π, an energy error of a few percent can cause a large error in the total phase advance. This in turn degrades the performance of auto-steering programs. We have developed a diagnostic program which generates and measures several betatron oscillations in the accelerator. It then analyzes this oscillation, looking for frequency changes which indicate energy errors. One can then compensate for or correct these energy errors. 6 refs., 1 fig

  18. Stochastic Kuramoto oscillators with discrete phase states

    Science.gov (United States)

    Jörg, David J.

    2017-09-01

    We present a generalization of the Kuramoto phase oscillator model in which phases advance in discrete phase increments through Poisson processes, rendering both intrinsic oscillations and coupling inherently stochastic. We study the effects of phase discretization on the synchronization and precision properties of the coupled system both analytically and numerically. Remarkably, many key observables such as the steady-state synchrony and the quality of oscillations show distinct extrema while converging to the classical Kuramoto model in the limit of a continuous phase. The phase-discretized model provides a general framework for coupled oscillations in a Markov chain setting.

  19. Stochastic Kuramoto oscillators with discrete phase states.

    Science.gov (United States)

    Jörg, David J

    2017-09-01

    We present a generalization of the Kuramoto phase oscillator model in which phases advance in discrete phase increments through Poisson processes, rendering both intrinsic oscillations and coupling inherently stochastic. We study the effects of phase discretization on the synchronization and precision properties of the coupled system both analytically and numerically. Remarkably, many key observables such as the steady-state synchrony and the quality of oscillations show distinct extrema while converging to the classical Kuramoto model in the limit of a continuous phase. The phase-discretized model provides a general framework for coupled oscillations in a Markov chain setting.

  20. Optimal parameters uncoupling vibration modes of oscillators

    Science.gov (United States)

    Le, K. C.; Pieper, A.

    2017-07-01

    This paper proposes a novel optimization concept for an oscillator with two degrees of freedom. By using specially defined motion ratios, we control the action of springs to each degree of freedom of the oscillator. We aim at showing that, if the potential action of the springs in one period of vibration, used as the payoff function for the conservative oscillator, is maximized among all admissible parameters and motions satisfying Lagrange's equations, then the optimal motion ratios uncouple vibration modes. A similar result holds true for the dissipative oscillator having dampers. The application to optimal design of vehicle suspension is discussed.

  1. Neuromorphic computing with nanoscale spintronic oscillators.

    Science.gov (United States)

    Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Yakushiji, Kay; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, Mark D; Grollier, Julie

    2017-07-26

    Neurons in the brain behave as nonlinear oscillators, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear oscillators. A simple estimation indicates that to fit 10 8 oscillators organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each oscillator must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting oscillators, a proof of concept of neuromorphic computing using nanoscale oscillators has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic oscillator (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic oscillators to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of oscillators.

  2. Introduction to classical and quantum harmonic oscillators

    CERN Document Server

    Bloch, Sylvan C

    2013-01-01

    From conch shells to lasers . harmonic oscillators, the timeless scientific phenomenon As intriguing to Galileo as they are to scientists today, harmonic oscillators have provided a simple and compelling paradigm for understanding the complexities that underlie some of nature's and mankind's most fascinating creations. From early string and wind instruments fashioned from bows and seashells to the intense precision of lasers, harmonic oscillators have existed in various forms, as objects of beauty and scientific use. And harmonic oscillation has endured as one of science's most fascinating con

  3. Theory of a quantum anharmonic oscillator

    International Nuclear Information System (INIS)

    Carusotto, S.

    1988-01-01

    The time evolution of a quantum single-quartic anharmonic oscillator is considered. The study is carried on in operational form by use of the raising and lowering operators of the oscillator. The equation of motion is solved by application of a new integration method based on iteration techniques, and the rigorous solutions that describe the time development of the displacement and momentum operators of the oscillator are obtained. These operators are presented as a Laplace transform and a subsequent inverse Laplace transform of suitable functionals. Finally, the results are employed to describe the time evolution of a quasiclassical anharmonic oscillator

  4. Waves and oscillations in nature an introduction

    CERN Document Server

    Narayanan, A Satya

    2015-01-01

    Waves and oscillations are found in large scales (galactic) and microscopic scales (neutrino) in nature. Their dynamics and behavior heavily depend on the type of medium through which they propagate.Waves and Oscillations in Nature: An Introduction clearly elucidates the dynamics and behavior of waves and oscillations in various mediums. It presents different types of waves and oscillations that can be observed and studied from macroscopic to microscopic scales. The book provides a thorough introduction for researchers and graduate students in assorted areas of physics, such as fluid dynamics,

  5. Chimera states in two-dimensional networks of locally coupled oscillators

    Science.gov (United States)

    Kundu, Srilena; Majhi, Soumen; Bera, Bidesh K.; Ghosh, Dibakar; Lakshmanan, M.

    2018-02-01

    Chimera state is defined as a mixed type of collective state in which synchronized and desynchronized subpopulations of a network of coupled oscillators coexist and the appearance of such anomalous behavior has strong connection to diverse neuronal developments. Most of the previous studies on chimera states are not extensively done in two-dimensional ensembles of coupled oscillators by taking neuronal systems with nonlinear coupling function into account while such ensembles of oscillators are more realistic from a neurobiological point of view. In this paper, we report the emergence and existence of chimera states by considering locally coupled two-dimensional networks of identical oscillators where each node is interacting through nonlinear coupling function. This is in contrast with the existence of chimera states in two-dimensional nonlocally coupled oscillators with rectangular kernel in the coupling function. We find that the presence of nonlinearity in the coupling function plays a key role to produce chimera states in two-dimensional locally coupled oscillators. We analytically verify explicitly in the case of a network of coupled Stuart-Landau oscillators in two dimensions that the obtained results using Ott-Antonsen approach and our analytical finding very well matches with the numerical results. Next, we consider another type of important nonlinear coupling function which exists in neuronal systems, namely chemical synaptic function, through which the nearest-neighbor (locally coupled) neurons interact with each other. It is shown that such synaptic interacting function promotes the emergence of chimera states in two-dimensional lattices of locally coupled neuronal oscillators. In numerical simulations, we consider two paradigmatic neuronal oscillators, namely Hindmarsh-Rose neuron model and Rulkov map for each node which exhibit bursting dynamics. By associating various spatiotemporal behaviors and snapshots at particular times, we study the chimera

  6. Oscillations of Difference Equations with Several Oscillating Coefficients

    Directory of Open Access Journals (Sweden)

    L. Berezansky

    2014-01-01

    Full Text Available We study the oscillatory behavior of the solutions of the difference equation Δx(n+∑i=1mpi(nx(τi(n=0,n∈N0[∇xn-∑i=1mpinxσin=0, n∈N] where (pi(n, 1≤i≤m are real sequences with oscillating terms, τi(n[σi(n], 1≤i≤m are general retarded (advanced arguments, and Δ[∇] denotes the forward (backward difference operator Δx(n=x(n+1-x(n[∇x(n=x(n-x(n-1]. Examples illustrating the results are also given.

  7. Gravitationally induced neutrino oscillation phases in static spacetimes

    International Nuclear Information System (INIS)

    Bhattacharya, T.; Habib, S.; Mottola, E.

    1999-01-01

    We critically examine the recent claim of a 'new effect' of gravitationally induced quantum mechanical phases in neutrino oscillations. Because this claim has generated some discussion in the literature we present here a straightforward calculation of the phase and clarify some of the conceptual issues involved, particularly in relation to the equivalence principle. When expressed in terms of the asymptotic energy of the neutrinos E and Schwarzschild radial coordinates r, the lowest order at which such a gravitational effect appears is (GMΔm 4 /ℎE 3 )ln(r B /r A ). copyright 1999 The American Physical Society

  8. Hepatocellular Carcinoma with Foamy Histiocyte-Like Appearance: A Deceptively Clear Cell Carcinoma Appearing Variant

    Directory of Open Access Journals (Sweden)

    Takuji Noro

    2010-08-01

    Full Text Available Hepatocellular carcinoma (HCC shows many pathological features, and it varies architecturally and cytologically. There have been many reports and discussions of the morphological features of HCC. A 63-year-old man was found to have a solitary tumor in liver segment 7 that was diagnosed as HCC. A partial resection of liver segment 7 was performed. Microscopically, the tumor lesion showed a moderately differentiated HCC. There was also a lesion with foamy histiocyte-like cells corresponding to the white lesion in the face of the cut tumor. Immunohistochemical staining showed that they were negative for CD68, S-100, vimentin, and HMB-45. The cytoplasm itself was negative on periodic acid Schiff (PAS and Sudan staining. Without immunohistological analysis, it is difficult to distinguish this HCC variant from clear cell carcinoma or metastases of renal cell carcinoma. It is important to recognize this type as a specific cytological variant of HCC that requires confirmation by immunohistochemistry. This report describes the case of a patient with a morphologically distinctive pattern of HCC with prominent cell cytoplasm that had a foamy histiocyte-like appearance. To the best of our knowledge, this is the first report of this HCC variant.

  9. Circuit oscillations in odor perception and memory.

    Science.gov (United States)

    Kay, Leslie M

    2014-01-01

    Olfactory system neural oscillations as seen in the local field potential have been studied for many decades. Recent research has shown that there is a functional role for the most studied gamma oscillations (40-100Hz in rats and mice, and 20Hz in insects), without which fine odor discrimination is poor. When these oscillations are increased artificially, fine discrimination is increased, and when rats learn difficult and highly overlapping odor discriminations, gamma is increased in power. Because of the depth of study on this oscillation, it is possible to point to specific changes in neural firing patterns as represented by the increase in gamma oscillation amplitude. However, we know far less about the mechanisms governing beta oscillations (15-30Hz in rats and mice), which are best associated with associative learning of responses to odor stimuli. These oscillations engage every part of the olfactory system that has so far been tested, plus the hippocampus, and the beta oscillation frequency band is the one that is most reliably coherent with other regions during odor processing. Respiratory oscillations overlapping with the theta frequency band (2-12Hz) are associated with odor sniffing and normal breathing in rats. They also show coupling in some circumstances between olfactory areas and rare coupling between the hippocampus and olfactory bulb. The latter occur in specific learning conditions in which coherence strength is negatively or positively correlated with performance, depending on the task. There is still much to learn about the role of neural oscillations in learning and memory, but techniques that have been brought to bear on gamma oscillations (current source density, computational modeling, slice physiology, behavioral studies) should deliver much needed knowledge of these events. © 2014 Elsevier B.V. All rights reserved.

  10. Linear stability analysis of collective neutrino oscillations without spurious modes

    Science.gov (United States)

    Morinaga, Taiki; Yamada, Shoichi

    2018-01-01

    Collective neutrino oscillations are induced by the presence of neutrinos themselves. As such, they are intrinsically nonlinear phenomena and are much more complex than linear counterparts such as the vacuum or Mikheyev-Smirnov-Wolfenstein oscillations. They obey integro-differential equations, for which it is also very challenging to obtain numerical solutions. If one focuses on the onset of collective oscillations, on the other hand, the equations can be linearized and the technique of linear analysis can be employed. Unfortunately, however, it is well known that such an analysis, when applied with discretizations of continuous angular distributions, suffers from the appearance of so-called spurious modes: unphysical eigenmodes of the discretized linear equations. In this paper, we analyze in detail the origin of these unphysical modes and present a simple solution to this annoying problem. We find that the spurious modes originate from the artificial production of pole singularities instead of a branch cut on the Riemann surface by the discretizations. The branching point singularities on the Riemann surface for the original nondiscretized equations can be recovered by approximating the angular distributions with polynomials and then performing the integrals analytically. We demonstrate for some examples that this simple prescription does remove the spurious modes. We also propose an even simpler method: a piecewise linear approximation to the angular distribution. It is shown that the same methodology is applicable to the multienergy case as well as to the dispersion relation approach that was proposed very recently.

  11. Indication of Electron Neutrino Appearance in the T2K experiment and its long-term implications

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    T2K (Tokai-to-Kamioka) is a long-baseline neutrino oscillation experiment primarily searching for oscillations of muon neutrinos into electron neutrinos. T2K will also make precise measurements of the atmospheric oscillation parameters via muon neutrino disappearance. The experiment uses 30 GeV protons from the new J-PARC Main Ring accelerator, located in Tokai, Japan, to generate a conventional neutrino beam to the Super-Kamiokande far detector. The hadron production measurements of the NA61 experiment at CERN were used to predict the neutrino fluxes at the near and far detectors. The T2K oscillation analysis compares the rates of observed and predicted muon and electron neutrino candidates in the far detector. We present first results based on data accumulated from January 2010 to March 2011. Six electron neutrino events pass the selection criteria for electron appearance at Super-Kamiokande, whereas the expected number of background events is 1.5±0.3. The probability of a fluctuation of the back...

  12. Introduction to focus issue: Mixed mode oscillations: Experiment, computation, and analysis

    DEFF Research Database (Denmark)

    Brøns, Morten; Kaper, T.J.; Rotstein, H.G.

    2008-01-01

    Mixed mode oscillations ( MMOs ) occur when a dynamical system switches between fast and slow motion and small and large amplitude. MMOs appear in a variety of systems in nature, and may be simple or complex. This focus issue presents a series of articles on theoretical, numerical, and experiment...

  13. Masculinity, consumerism, and appearance: a look at men's hair.

    Science.gov (United States)

    Ricciardelli, Rosemary

    2011-05-01

    Historically, being concerned about appearance was stereotypically associated with women. Now masculinities too have become embedded in appearance norms. Consequently men too are increasingly concerned about their appearance. Via interviews with 14 Canadian men, the role of hair in self-identification and both satisfaction and dissatisfaction with appearance is examined. Emergent themes suggest that masculinity and appearance are increasingly intertwined, and consumer culture cultivates a climate that encourages men to view their appearance as something worthy of investment. Findings suggest that men are concerned about their appearance-specifically their hair-and that there is a relationship between masculinity, appearance, and self-identification. Findings are discussed within theories of masculinity and consumerism.

  14. Magnetic resonance appearance of adrenal hemorrhage in a neonate

    International Nuclear Information System (INIS)

    Willemse, A.P.P.; Feldberg, M.A.M.; Witkamp, T.D.; Coppes, M.J.; Kramer, P.P.G.

    1989-01-01

    The Magnetic Resonance (MR) appearance of adrenal hemorrhage in a neonate is described and compared with Ultrasound (US). The value of US studies in adrenal neonatal hemorrhage is well known. We present the MR appearance of this common condition. (orig.)

  15. A comprehensive search for “anomalies” from neutrino and anti-neutrino oscillations at large mass differences (Δm^2 ~ 1eV^2) with two LAr–TPC imaging detectors at different distances from the CERN-PS.

    CERN Document Server

    Rubbia, C; Bagliani, D; Baibussinov, B; Bilokon, H; Boffelli, F; Bonesini, M; Calligarich, E; Canci, N; Centro, S; Cesana, A; Cieslik, K; Cline, D B; Cocco, A G; De Gerone, M; Dequal, D; Dermenev, A; Dolfini, R; Dussoni, S; Farnese, C; Fava, A; Ferrari, A; Fiorillo, G; Garvey, G T; Gatti, F; Gibin, D; Gigli Berzolari, A; Gninenko, S; Guber, F; Guglielmi, A; Haranczyk, M; Holeczek, J; Ivashkin, A; Kirsanov, M; Kisiel, J; Kochanek, I; Kurepin, A; Łagoda, J; Louis, W C; Lucchini, G; Mania, S; Mannocchi, G; Matveev, V; Menegolli, A; Meng, G; Mills, G B; Montanari, C; Otwinowski, S; Palczewski, T J; Perfetto, F; Periale, L; Picchi, P; Pietropaolo, F; Płoński, P; Rappoldi, A; Raselli, G L; Rossella, M; Sala, P; Scantamburlo, E; Scaramelli, A; Segreto, E; Sergiampietri, F; Suvorova, O; Stefan, D; Stepaniak, J; Sulej, R; Terrani, M; Testera, G; Tlisov, D; Trinchero, G; Van de Water, R G; Varanini, F; Ventura, S; Vignoli, C; Wang, H G; Yang, X; Zani, A; Zaremba, K

    2011-01-01

    The present proposal describes an experimental search of sterile neutrinos beyond the Standard Model with the CERN-PS beam and the innovative technology of imaging in ultra-pure cryogenic liquid Argon. The proposal is based on two strictly identical LAr-TPC detectors observing the electron-neutrino signal in the ”Far” and “Near” positions, the first one of about 600 tons placed 850 m the second one of about 150 tons at about 6.5 times shorter distance from the proton target. This project will exploit the ICARUS T600 — now running in the underground experiment CNGS2 with neutrinos from the CERN-SPS — moved from GranSasso to the CERN “Far” position. The additional T150 will be constructed and located in the “Near” position. In the two positions, the radial and energy spectra of the nu_e beam are practically identical. Comparing the two detectors, in absence of oscillations, all cross sections and experimental biases cancel out and the two experimentally observed event distributions must be ...

  16. High-frequency plasma oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Akhiezer, A I; Fainberg, Y B; Sitenko, A G; Stepanov, K; Kurilko, V; Gorbatenko, M; Kirochkin, U [Academy of Sciences of the Ukrainian SSR (USSR)

    1958-07-01

    It is well known that the electrical conductivity of a plasma, the ion-electron equilibration time, and the time required to heat the electron component of the plasma all increase greatly with increasing temperature. Consequently, the usual method of Joule heating a plasma may be difficult to apply in the region of high temperatures (> 10{sup 6}K), especially if the plasma current alone, without any additional measures, is used to generate magnetic fields for the confinement of the plasma. Therefore, it is of interest to study methods of plasma heating that do not directly use Joule heat, especially methods by which energy is directly supplied to the ion component during the time between collisions. Some of these methods make use of ionic resonance as well as other resonance phenomena which can occur in plasma in an external magnetic field. This paper deals with certain aspects of the theory of high-frequency plasma oscillations.

  17. Optimal oscillation-center transformations

    International Nuclear Information System (INIS)

    Dewar, R.L.

    1984-08-01

    A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed

  18. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  19. Decay ratio for third order Brownian oscillators

    International Nuclear Information System (INIS)

    Konno, H.; Kanemoto, S.

    1998-01-01

    We have obtained the analytical expressions of the decay ratios for two types of third order Brownian oscillators which are generalizations of the second order Brownian oscillator driven by the Gaussian-white noise. The resulting expressions will provide us useful baseline information for more complicated practical problems and their applications

  20. Electromagnetic Radiation Originating from Unstable Electron Oscillations

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Pécseli, Hans

    1975-01-01

    Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

  1. Synchronization of indirectly coupled Lorenz oscillators

    Indian Academy of Sciences (India)

    Synchronization of indirectly coupled Lorenz oscillators: An experimental study. Amit Sharma Manish Dev Shrimali. Synchronization, Coupled Systems and Networks Volume 77 Issue 5 November 2011 pp 881-889 ... The in-phase and anti-phase synchronization of indirectly coupled chaotic oscillators reported in Phys. Rev ...

  2. Dependence of synchronization frequency of Kuramoto oscillators ...

    Indian Academy of Sciences (India)

    Kuramoto oscillators have been proposed earlier as a model for interacting systems that exhibit synchronization. In this article, we study the difference between networks with symmetric and asymmetric distribution of natural frequencies. We first indicate that synchronization frequency of oscillators in a completely connected ...

  3. Neutrino oscillations and neutrino-electron scattering

    International Nuclear Information System (INIS)

    Kayser, B.; Rosen, S.P.

    1980-10-01

    Neutrino flavor oscillations can significantly alter the cross section for neutrino-electron scattering. As a result, such oscillations can affect the comparison between existing reactor data and theories of neutral-current processes. They may also lead to strikingly large effects in high-energy accelerator experiments

  4. Discontinuous Spirals of Stable Periodic Oscillations

    DEFF Research Database (Denmark)

    Sack, Achim; Freire, Joana G.; Lindberg, Erik

    2013-01-01

    We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...

  5. Parametric resonance in neutrino oscillations in matter

    Indian Academy of Sciences (India)

    Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we ...

  6. Compensation of oscillation coupling induced by solenoids

    International Nuclear Information System (INIS)

    Zelinskij, A.Yu.; Karnaukhov, I.M.; Shcherbakov, A.A.

    1988-01-01

    Methods for construction of various schemes of oscillation coupling compensation, induced by solenoids in charged particle storage rings, are described. Peculiarities of magnetic structure, enabling to localize oscillation coupling in wide energy range are discussed. Results of calculation of compensation schemes for design of NR-2000 storage ring spin rotation are presented

  7. Accelerator-based neutrino oscillation searches

    International Nuclear Information System (INIS)

    Whitehouse, D.; Rameika, G.

    1993-01-01

    This paper attempts to summarize the neutrino oscillation section of the Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Beam Facilities. There were very lively discussions about the merits of the different oscillation channels, experiments, and facilities, but the authors believe a substantial consensus emerged

  8. Oscillating and rotating sine-Gordon system

    DEFF Research Database (Denmark)

    Olsen, O. H.; Samuelsen, Mogens Rugholm

    1986-01-01

    The interaction between a 2π kink and the background or vacuum is investigated in the pure sine-Gordon system. For an oscillating background (i.e., the k=0 part of the phonon spectrum) the 2π kink oscillates, while for increasing or decreasing vacuum two phenomena have been observed, depending...

  9. A Class-F CMOS Oscillator

    NARCIS (Netherlands)

    Babaie, M.; Staszewski, R.B.

    2013-01-01

    An oscillator topology demonstrating an improved phase noise performance is proposed in this paper. It exploits the time-variant phase noise model with insights into the phase noise conversion mechanisms. The proposed oscillator is based on enforcing a pseudo-square voltage waveform around the LC

  10. Oscillator clustering in a resource distribution chain

    DEFF Research Database (Denmark)

    Postnov, D.; Sosnovtseva, Olga; Mosekilde, Erik

    2005-01-01

    separate the inherent dynamics of the individual oscillator from the properties of the coupling network. Illustrated by examples from microbiological population dynamics, renal physiology, and electronic oscillator theory, we show how competition for primary resources in a resource distribution chain leads...

  11. Mass and oscillations of Dirac neutrinos

    International Nuclear Information System (INIS)

    Collot, J.

    1989-01-01

    In the most economical extension of the standard model, we have presented the theory of massive Dirac neutrinos. We have particularly emphasized that, in this model, a complete analogy between quarks and leptons can be erected and predicts neutrino flavor oscillations. We have reviewed the last experimental results concerning kinetic neutrino mass experiments and neutrino oscillation investigations

  12. A simple approach to nonlinear oscillators

    International Nuclear Information System (INIS)

    Ren Zhongfu; He Jihuan

    2009-01-01

    A very simple and effective approach to nonlinear oscillators is suggested. Anyone with basic knowledge of advanced calculus can apply the method to finding approximately the amplitude-frequency relationship of a nonlinear oscillator. Some examples are given to illustrate its extremely simple solution procedure and an acceptable accuracy of the obtained solutions.

  13. Experimental observation of shear thickening oscillation

    DEFF Research Database (Denmark)

    Nagahiro, Shin-ichiro; Nakanishi, Hiizu; Mitarai, Namiko

    2013-01-01

    We report experimental observations of the shear thickening oscillation, i.e. the spontaneous macroscopic oscillation in the shear flow of severe shear thickening fluid. Using a density-matched starch-water mixture, in the cylindrical shear flow of a few centimeters flow width, we observed...

  14. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

    1996-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  15. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

    1999-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  16. Plasmon field enhancement oscillations induced by strain-mediated coupling between a quantum dot and mechanical oscillator.

    Science.gov (United States)

    He, Yong

    2017-06-23

    We utilize the surface plasmon field of a metal nanoparticle (MNP) to show strain-mediated coupling in a quantum dot-mechanical resonator hybrid system including a quantum dot (QD) embedded within a conical nanowire (NW) and a MNP in the presence of an external field. Based on the numerical solutions of the master equation, we find that a slow oscillation, originating from the strain-mediated coupling between the QD and the NW, appears in the time evolution of the plasmon field enhancement. The results show that the period (about [Formula: see text]) of the slow oscillation is equal to that of the mechanical resonator of NW, which suggests that the time-resolved measurement of the plasmon field enhancement can be easily achieved based on the current experimental conditions. Its amplitude increases with the increasing strain-mediated coupling strength, and under certain conditions there is a linear relationship between them. The slow oscillation of the plasmon field enhancement provides valuable tools for measurements of the mechanical frequency and the strain-mediated coupling strength.

  17. 22 CFR 41.102 - Personal appearance of applicant.

    Science.gov (United States)

    2010-04-01

    ... interview. (d) Cases in which personal appearance may not be waived. A consular officer or the Deputy... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Personal appearance of applicant. 41.102... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Application for Nonimmigrant Visa § 41.102 Personal appearance of...

  18. Theory of terahertz electric oscillations by supercooled superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Mishonov, Todor M; Mishonov, Mihail T [Department of Theoretical Physics, Faculty of Physics, University of Sofia St Kliment Ohridski, 5 J Bourchier Boulevard, 1164 Sofia (Bulgaria); Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200 D B-3001 Leuven (Belgium)

    2005-11-15

    We predict that below T{sub c} a regime of negative differential conductivity (NDC) can be reached. The superconductor should be supercooled to Toscillations. Such generators can be used in the superconducting electronics as a new type THz source of radiation. Oscillations can be modulated by the change of the bias voltage, electrostatic doping by a gate electrode when the superconductor is the channel of a field effect transistor, or by light. When small amplitude oscillations are stabilized near the critical temperature T{sub c} the generator can be used as a bolometer. NDC, which is essential for the applications, is predicted on the basis of analysis of known results for fluctuation conductivity, obtained in previous papers by solving the Boltzmann kinetic equation for the Cooper pairs metastable in the normal phase. The Boltzmann equation for fluctuation Cooper pairs is a result of state-of-the-art application of the microscopic theory of superconductivity. Our theoretical conclusions are based on some approximations like time dependent Ginzburg-Landau theory initially derived for gapless superconductors, but nevertheless can reliably predict the appearance of NDC. NDC is the main ingredient of the proposed technical applications. The maximal frequency at which superconductors can operate as generators is determined by the critical temperature {Dirac_h}/2{pi}{omega}{sub max} {approx} k{sub B}T{sub c}. For high-T{sub c} superconductors this maximal frequency falls well inside the terahertz range. Technical conditions to avoid nucleation of the superconducting phase are briefly discussed. We suggest that nanostructured high-T{sub c} superconductors patterned in a single chip can

  19. Pressure sensitivity of flow oscillations in postocclusive reactive skin hyperemia.

    Science.gov (United States)

    Strucl, M; Peterec, D; Finderle, Z; Maver, J

    1994-05-01

    Skin blood flow was monitored using a laser-Doppler (LD) flowmeter in 21 healthy volunteers after an occlusion of the digital arteries. The peripheral vascular bed was exposed to occlusion ischemia of varying duration (1, 4, or 8 min) and to a change in digital arterial pressure produced by different positions of the arm above heart level to characterize the pattern of LD flow oscillations in postocclusive reactive hyperemia (PRH) and to elucidate the relevance of metabolic and myogenic mechanisms in governing its fundamental frequency. The descending part of the hyperemic flow was characterized by the appearance of conspicuous periodic oscillations with a mean fundamental frequency of 7.2 +/- 1.5 cycles/min (SD, n = 9), as assessed by a Fourier transform frequency analysis of 50-s sections of flow. The mean respiratory frequency during the periods of flow frequency analysis was 17.0 +/- 2.2 (SD, n = 9), and the PRH oscillations remained during apnea in all tested subjects. The area under the maximum flow curve increased significantly with prolongation of the occlusion (paired t test, P blood pressure in the digital arteries, which suggests the predominant role of a metabolic component in this part of the PRH response. In contrast, the fundamental frequency of PRH oscillations exhibited a significant decrease with a reduction in the estimated digital arterial pressure (linear regression, b = 0.08, P < 0.001; n = 12), but did not change with the prolongation of arterial occlusion despite a significant increase in mean LD flow (paired t test, P < 0.001; n = 9).(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Atmospheric neutrino oscillations for earth tomography

    International Nuclear Information System (INIS)

    Winter, Walter

    2016-01-01

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can measure the lower mantle density of the earth with a precision at the level of a few percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  1. Self oscillating PWM modulators, a topological comparison

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    or fs/ð range respectively, where fs is the switching frequency of the converter. For some applications this will require unacceptable high switching frequency to achieve enough control loop bandwidth for the desired dynamic performance. With self oscillating modulators, the open loop bandwidth is equal...... to fs which makes this type of modulators an excellent choice for a wide range of applications. Self oscillating PWM modulators can be made in a number of ways, either as voltage or current mode modulators, and the self oscillating behavior can be achieved either by using hysteresis control...... or by shaping the open loop function of the modulator so its gain and phase response causes a closed loop natural oscillation. The two main types of self oscillating modulators have many similarities, but differences in dynamic performance and linearity are present. The work presented is related to the author...

  2. Chemical sensor with oscillating cantilevered probe

    Science.gov (United States)

    Adams, Jesse D

    2013-02-05

    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.

  3. Improved memristor-based relaxation oscillator

    KAUST Repository

    Mosad, Ahmed G.

    2013-09-01

    This paper presents an improved memristor-based relaxation oscillator which offers higher frequency and wider tunning range than the existing reactance-less oscillators. It also has the capability of operating on two positive supplies or alternatively a positive and negative supply. Furthermore, it has the advantage that it can be fully integrated on-chip providing an area-efficient solution. On the other hand, The oscillation concept is discussed then a complete mathematical analysis of the proposed oscillator is introduced. Furthermore, the power consumption of the new relaxation circuit is discussed and validated by the PSPICE circuit simulations showing an excellent agreement. MATLAB results are also introduced to demonstrate the resistance range and the corresponding frequency range which can be obtained from the proposed relaxation oscillator. © 2013 Elsevier Ltd.

  4. Two-oscillator model of trapped-modes interaction in a nonlinear bilayer fish-scale metamaterial

    OpenAIRE

    Tuz, Vladimir R.; Kochetov, Bogdan A.; Kochetova, Lyudmila A.; Mladyonov, Pavel L.; Prosvirnin, Sergey L.

    2014-01-01

    We discuss the similarity between the nature of resonant oscillations in two nonlinear systems, namely, a chain of coupled Duffing oscillators and a bilayer fish-scale metamaterial. In such systems two different resonant states arise which differ in their spectral lines. The spectral line of the first resonant state has a Lorentzian form, while the second one has a Fano form. This difference leads to a specific nonlinear response of the systems which manifests itself in appearance of closed l...

  5. A novel optogenetically tunable frequency modulating oscillator.

    Directory of Open Access Journals (Sweden)

    Tarun Mahajan

    Full Text Available Synthetic biology has enabled the creation of biological reconfigurable circuits, which perform multiple functions monopolizing a single biological machine; Such a system can switch between different behaviours in response to environmental cues. Previous work has demonstrated switchable dynamical behaviour employing reconfigurable logic gate genetic networks. Here we describe a computational framework for reconfigurable circuits in E.coli using combinations of logic gates, and also propose the biological implementation. The proposed system is an oscillator that can exhibit tunability of frequency and amplitude of oscillations. Further, the frequency of operation can be changed optogenetically. Insilico analysis revealed that two-component light systems, in response to light within a frequency range, can be used for modulating the frequency of the oscillator or stopping the oscillations altogether. Computational modelling reveals that mixing two colonies of E.coli oscillating at different frequencies generates spatial beat patterns. Further, we show that these oscillations more robustly respond to input perturbations compared to the base oscillator, to which the proposed oscillator is a modification. Compared to the base oscillator, the proposed system shows faster synchronization in a colony of cells for a larger region of the parameter space. Additionally, the proposed oscillator also exhibits lesser synchronization error in the transient period after input perturbations. This provides a strong basis for the construction of synthetic reconfigurable circuits in bacteria and other organisms, which can be scaled up to perform functions in the field of time dependent drug delivery with tunable dosages, and sets the stage for further development of circuits with synchronized population level behaviour.

  6. Are the North Atlantic oscillation and the southern oscillation related in any time-scale?

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, R.; Ribera, P.; Hernandez, E. [Universidad Complutense de Madrid (Spain). Facultad de Ciencias Fisicas; Gimenoo, L. [Fac. Ciencias, Univ. Vigo, Ourense (Spain)

    2000-02-01

    The north Atlantic oscillation (NAO) and the southern oscillation (SO) are compared from the standpoint of a possible common temporal scale of oscillation. To do this a cross-spectrum of the temporal series of NAO and SO indices was determined, finding a significant common oscillation of 6-8 years. To assure this finding, both series were decomposed in their main oscillations using singular spectrum analysis (SSA). Resulting reconstructed series of 6-8 years' oscillation were then cross-correlated without and with pre-whitened, the latter being significant. The main conclusion is a possible relationship between a common oscillation of 6-8 years that represents about 20% of the SO variance and about 25% of the NAO variance. (orig.)

  7. PRE-ERUPTION OSCILLATIONS IN THIN AND LONG FEATURES IN A QUIESCENT FILAMENT

    International Nuclear Information System (INIS)

    Joshi, Anand D.; Hanaoka, Yoichiro; Suematsu, Yoshinori; Morita, Satoshi; Yurchyshyn, Vasyl; Cho, Kyung-Suk

    2016-01-01

    We investigate the eruption of a quiescent filament located close to an active region. Large-scale activation was observed in only half of the filament in the form of pre-eruption oscillations. Consequently only this half erupted nearly 30 hr after the oscillations commenced. Time-slice diagrams of 171 Å images from the Atmospheric Imaging Assembly were used to study the oscillations. These were observed in several thin and long features connecting the filament spine to the chromosphere below. This study traces the origin of such features and proposes their possible interpretation. Small-scale magnetic flux cancellation accompanied by a brightening was observed at the footpoint of the features shortly before their appearance, in images recorded by the Helioseismic and Magnetic Imager. A slow rise of the filament was detected in addition to the oscillations, indicating a gradual loss of equilibrium. Our analysis indicates that a change in magnetic field connectivity between two neighbouring active regions and the quiescent filament resulted in a weakening of the overlying arcade of the filament, leading to its eruption. It is also suggested that the oscillating features are filament barbs, and the oscillations are a manifestation during the pre-eruption phase of the filaments.

  8. PRE-ERUPTION OSCILLATIONS IN THIN AND LONG FEATURES IN A QUIESCENT FILAMENT

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Anand D.; Hanaoka, Yoichiro; Suematsu, Yoshinori; Morita, Satoshi [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Yurchyshyn, Vasyl; Cho, Kyung-Suk, E-mail: anand.joshi@nao.ac.jp [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of)

    2016-12-20

    We investigate the eruption of a quiescent filament located close to an active region. Large-scale activation was observed in only half of the filament in the form of pre-eruption oscillations. Consequently only this half erupted nearly 30 hr after the oscillations commenced. Time-slice diagrams of 171 Å images from the Atmospheric Imaging Assembly were used to study the oscillations. These were observed in several thin and long features connecting the filament spine to the chromosphere below. This study traces the origin of such features and proposes their possible interpretation. Small-scale magnetic flux cancellation accompanied by a brightening was observed at the footpoint of the features shortly before their appearance, in images recorded by the Helioseismic and Magnetic Imager. A slow rise of the filament was detected in addition to the oscillations, indicating a gradual loss of equilibrium. Our analysis indicates that a change in magnetic field connectivity between two neighbouring active regions and the quiescent filament resulted in a weakening of the overlying arcade of the filament, leading to its eruption. It is also suggested that the oscillating features are filament barbs, and the oscillations are a manifestation during the pre-eruption phase of the filaments.

  9. LGBTQ Women, Appearance Negotiations, and Workplace Dress Codes.

    Science.gov (United States)

    Reddy-Best, Kelly L

    2018-01-01

    The purpose of this study was to explore LGBTQ women's experiences with unwritten or formal dress codes at work. I asked: What are LGBTQ women's experiences in the workplace with appearance management, and what are LGBTQ women's experiences navigating the written and unwritten dress codes in the workplace? To answer the research question, interviews were conducted with 24 self-identifying LGBTQ women. Six key themes emerged from the data. Themes included (1) expressed sexual identity in appearance, (2) unwritten dress codes in work environments did not always allow for expression of sexual identity in appearance, (3) motivations for pressure or desire to conceal expression of sexual identity in appearance at work, (4) negotiations of revealing or concealing sexual identity in appearance in the workplace impacted levels of comfort and confidence, (5) verbal and nonverbal negative experiences related to appearance at work, and (6) received compliments about appearance at work.

  10. Adolescents' reasons for tanning and appearance motives: a preliminary study.

    Science.gov (United States)

    Prior, Suzanne M; Fenwick, Kimberley D; Peterson, Jasmine C

    2014-01-01

    We examined adolescents' reasons for tanning and how these relate to appearance evaluation and orientation. Two hundred and sixty-four Canadian adolescents (age range 15-19 years) in grades 10, 11, and 12 completed a survey that included scales measuring their reasons for tanning, appearance evaluation, and appearance orientation. It was found that girls and boys differed on four of nine subscales measuring reasons for tanning. Girls believed more strongly than boys that tanning improved their general appearance and that friends influenced their decision to tan. Girls also expressed less concern than boys that tanning caused immediate skin damage or premature aging. The pattern of correlations between the reasons for tanning and appearance orientation was similar for girls and boys. For both, appearance reasons for tanning and sociocultural influences on tanning were positively associated with appearance orientation. Suggestions for future research with adolescents and a proposal for a guiding model are provided. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Secular variation of the Pacific Decadal Oscillation, the North Pacific Oscillation and climatic jumps in a multi-millennial simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, B.G. [CSIRO Marine and Atmospheric Research, PO Box 1, Melbourne (Australia)

    2008-04-15

    Outputs from a 10,000-year simulation with a coupled global climatic model for present climatic conditions have been used to investigate the behaviour of the Pacific Decadal Oscillation (PDO), the North Pacific Oscillation (NPO) and related phenomena. The analysis reveals a wide range of temporal variability for these Oscillations, suggesting that observations to date provide only a limited sample of possible outcomes. In addition, the simulation suggests that the current observed phase relation between the PDO and NPO may not be typical of longer-term variability. Climatic jumps appear to be a ubiquitous feature of climatic variability, and while, as observed, the most common interval between such jumps is about 20 years, intervals of up to 100 years occur in the simulation. The probability density functions of the PDO and NPO are very close to Gaussian, with the PDO being represented by an auto-regressive function of order one, while the NPO consisted of white noise. An FFT analysis of PC1 of the PDO revealed periodicities concentrated near 10 years, while for the NPO the principal periodicities were decadal to bidecadal. Global distributions of the distributions of the correlations between PC1 or the NPO and selected climatic variables were similar, and in agreement with observations. These correlations highlight the inter-relationships between these two Oscillations. The above correlations were not necessarily stable in time for a given geographical point, with transitions occurring between positive and negative extremes. Climatic jumps were identified with transitions of both the PDO and NPO, with magnitudes of importance as regards climatic perturbations. Spatial patterns of the changes associated with such jumps have global scales, and the need to consider the implications of these jumps in regard to greenhouse induced climatic change is noted. (orig.)

  12. B-periodic oscillations in the Hall-resistance induced by a dc-current-bias under combined microwave-excitation and dc-current bias in the GaAs/AlGaAs 2D system.

    Science.gov (United States)

    Liu, Han-Chun; Reichl, C; Wegscheider, W; Mani, R G

    2018-05-18

    We report the observation of dc-current-bias-induced B-periodic Hall resistance oscillations and Hall plateaus in the GaAs/AlGaAs 2D system under combined microwave radiation- and dc bias excitation at liquid helium temperatures. The Hall resistance oscillations and plateaus appear together with concomitant oscillations also in the diagonal magnetoresistance. The periods of Hall and diagonal resistance oscillations are nearly identical, and source power (P) dependent measurements demonstrate sub-linear relationship of the oscillation amplitude with P over the span 0 < P ≤ 20 mW.

  13. Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

    Science.gov (United States)

    Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

    2015-01-01

    During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

  14. Satisfaction with Appearance and the Desired Treatment to Improve Aesthetics

    Directory of Open Access Journals (Sweden)

    Bader K. Al-Zarea

    2013-01-01

    Full Text Available Objective. To identify participants’ satisfaction with appearance and the desired treatment to improve aesthetics. Materials and Methods. 220 participants (127 males and 93 females, mean age = 21.4 ± 1.5 years were recruited into the study. A structured questionnaire was used to assess patients’ satisfaction with appearance and what treatment they desire to improve aesthetics. Participants scored the level of satisfaction with appearance using visual analogue scale. Results. The VAS mean score of satisfaction with general appearance was 6.8 ± 2.3. Half participants were dissatisfied with tooth appearance and 65.9% were dissatisfied with tooth colour. Higher VAS scores were associated with higher desire for all treatments that improve tooth appearance (. Dissatisfaction with tooth appearance increased with increased dissatisfaction with teeth colour, feeling of poor tooth alignment, presence of fractured anterior teeth, and increased desire for orthodontic, crowns, and dentures treatments (. Dissatisfaction with tooth colour was associated with increased desire for tooth whitening and tooth coloured fillings (. Conclusions. Participants had high levels of dissatisfaction with tooth appearance and tooth colour. Dissatisfaction with tooth colour contributed to the increased dissatisfaction with tooth appearance. Dissatisfaction with tooth appearance, colour, alignment, and condition was significantly related to high desire for aesthetic treatments.

  15. Selecting fillers on emotional appearance improves lineup identification accuracy.

    Science.gov (United States)

    Flowe, Heather D; Klatt, Thimna; Colloff, Melissa F

    2014-12-01

    Mock witnesses sometimes report using criminal stereotypes to identify a face from a lineup, a tendency known as criminal face bias. Faces are perceived as criminal-looking if they appear angry. We tested whether matching the emotional appearance of the fillers to an angry suspect can reduce criminal face bias. In Study 1, mock witnesses (n = 226) viewed lineups in which the suspect had an angry, happy, or neutral expression, and we varied whether the fillers matched the expression. An additional group of participants (n = 59) rated the faces on criminal and emotional appearance. As predicted, mock witnesses tended to identify suspects who appeared angrier and more criminal-looking than the fillers. This tendency was reduced when the lineup fillers matched the emotional appearance of the suspect. Study 2 extended the results, testing whether the emotional appearance of the suspect and fillers affects recognition memory. Participants (n = 1,983) studied faces and took a lineup test in which the emotional appearance of the target and fillers was varied between subjects. Discrimination accuracy was enhanced when the fillers matched an angry target's emotional appearance. We conclude that lineup member emotional appearance plays a critical role in the psychology of lineup identification. The fillers should match an angry suspect's emotional appearance to improve lineup identification accuracy. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  16. Neutrino oscillations in magnetically driven supernova explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kawagoe, Shio; Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan); Takiwaki, Tomoya, E-mail: shio.k@nao.ac.jp, E-mail: takiwaki.tomoya@nao.ac.jp, E-mail: kkotake@th.nao.ac.jp [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan)

    2009-09-01

    We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ{sub 13} (sin{sup 2} 2θ{sub 13} ∼> 10{sup −3}), we show that survival probabilities of ν-bar {sub e} and ν{sub e} seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of ν-bar {sub e} observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the ν{sub e} signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the ν-bar {sub e} and ν{sub e} signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.

  17. Neutrino oscillations in magnetically driven supernova explosions

    Science.gov (United States)

    Kawagoe, Shio; Takiwaki, Tomoya; Kotake, Kei

    2009-09-01

    We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ13 (sin2 2θ13 gtrsim 10-3), we show that survival probabilities of bar nue and νe seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of bar nue observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the νe signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the bar nue and νe signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.

  18. Multivariate Time Series Decomposition into Oscillation Components.

    Science.gov (United States)

    Matsuda, Takeru; Komaki, Fumiyasu

    2017-08-01

    Many time series are considered to be a superposition of several oscillation components. We have proposed a method for decomposing univariate time series into oscillation components and estimating their phases (Matsuda & Komaki, 2017 ). In this study, we extend that method to multivariate time series. We assume that several oscillators underlie the given multivariate time series and that each variable corresponds to a superposition of the projections of the oscillators. Thus, the oscillators superpose on each variable with amplitude and phase modulation. Based on this idea, we develop gaussian linear state-space models and use them to decompose the given multivariate time series. The model parameters are estimated from data using the empirical Bayes method, and the number of oscillators is determined using the Akaike information criterion. Therefore, the proposed method extracts underlying oscillators in a data-driven manner and enables investigation of phase dynamics in a given multivariate time series. Numerical results show the effectiveness of the proposed method. From monthly mean north-south sunspot number data, the proposed method reveals an interesting phase relationship.

  19. Introduction to Classical and Quantum Harmonic Oscillators

    International Nuclear Information System (INIS)

    Latal, H

    1997-01-01

    As the title aptly states, this book deals with harmonic oscillators of various kinds, from classical mechanical and electrical oscillations up to quantum oscillations. It is written in a lively language, and occasional interspersed anecdotes make the reading of an otherwise mathematically oriented text quite a pleasure. Although the author claims to have written an 'elementary introduction', it is certainly necessary to have a good deal of previous knowledge in physics (mechanics, electrodynamics, quantum theory), electrical engineering and, of course, mathematics in order to follow the general line of his arguments. The book begins with a thorough treatment of classical oscillators (free, damped, forced) that is followed by an elaboration on Fourier analysis. Lagrange and Hamilton formalisms are then introduced before the problem of coupled oscillations is attacked. A chapter on statistical perspectives leads over to the final discussion of quantum oscillations. With the book comes a diskette containing a number of worksheets (Microsoft Excel) that can be used by the reader for instant visualization to get a better qualitative and quantitative understanding of the material. To the reviewer it seems difficult to pinpoint exactly the range of prospective readership of the book. It can certainly not be intended as a textbook for students, but rather as a reference book for teachers of physics or researchers, who want to look up one or other aspect of harmonic oscillations, for which purpose the diskette represents a very valuable tool. (book review)

  20. Satisfaction with appearance and the desired treatment to improve aesthetics.

    Science.gov (United States)

    Al-Zarea, Bader K

    2013-01-01

    Objective. To identify participants' satisfaction with appearance and the desired treatment to improve aesthetics. Materials and Methods. 220 participants (127 males and 93 females, mean age = 21.4 ± 1.5 years) were recruited into the study. A structured questionnaire was used to assess patients' satisfaction with appearance and what treatment they desire to improve aesthetics. Participants scored the level of satisfaction with appearance using visual analogue scale. Results. The VAS mean score of satisfaction with general appearance was 6.8 ± 2.3. Half participants were dissatisfied with tooth appearance and 65.9% were dissatisfied with tooth colour. Higher VAS scores were associated with higher desire for all treatments that improve tooth appearance (P feeling of poor tooth alignment, presence of fractured anterior teeth, and increased desire for orthodontic, crowns, and dentures treatments (P desire for tooth whitening and tooth coloured fillings (P desire for aesthetic treatments.