WorldWideScience

Sample records for experimental power spectra

  1. Correlation Functions and Power Spectra

    DEFF Research Database (Denmark)

    Larsen, Jan

    2006-01-01

    The present lecture note is a supplement to the textbook Digital Signal Processing by J. Proakis and D.G. Manolakis used in the IMM/DTU course 02451 Digital Signal Processing and provides an extended discussion of correlation functions and power spectra. The definitions of correlation functions...

  2. Hierarchical resolution of power spectra

    Science.gov (United States)

    Badii, R.; Finardi, M.; Broggi, G.; Sepúlveda, M. A.

    1992-09-01

    We identify the basic ingredients determining the structure of the power spectra of non-linear dynamical systems in a hierarchical order of importance. The analysis, performed with the help of symbolic methods, shows that dynamical invariants such as topological and metric properties of the symbolic orbits explain the main qualitative features of the spectra, whereas the coordinate-dependent values of the observable itself represent a less relevant contribution. Consideration of simple dynamical models with increasing number of topological transition rules evidences the formation of coherent structures (peaks) and explains their position and size. By constructing the parse tree of the allowed symbolic itineraries, it is possible to estimate conditional probabilities by considering orbits belonging to adjacent tree levels. Accordingly, a Markov transition matrix is obtained for each level l and is used to generate signals with statistical properties which approximate those of the actual one increasingly better for l → ∞. A considerable improvement is achieved by recoding the original signal in terms of variable-length words and by re-applying the above procedure to the transformed signal, which is equivalent to a renormalization operation of the associated dynamical map. The accuracy of the estimates is directly related to the convergence of the scaling function for the conditional probabilities. Analytic results are presented for the simplest five Markov models arising from piecewise-linear, continuous, one-dimensional maps. Numerical studies have been performed for the logistic and Hénon maps and for the Lorenz system.

  3. Experimental determination of physical processes in space, leading to deviations of radio synchrotron radiation spectra from the power law

    Science.gov (United States)

    Men', A. V.

    2008-02-01

    We present universal formulas for spectral characteristics of cosmic radio sources of synchrotron radiation upon the presence of spectral density maxima at certain frequencies (spectra with negative curvature) taking into account most typical physical processes observed in space. On the basis of long-term observations of angular radiation structure of cosmic radio sources in the decameter wavelength range by the URAN radio interferometer system, we determine most probable physical processes resulting in spectra with extremum values for several quasars, radio galaxies, and their separate components. On the basis of these data, we estimate some parameters of cosmic medium, magnetic field, and angular sizes of compact radio sources and their components.

  4. Power spectra of currents off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    Current measurements were carried out using a recording current meter across the continental shelf off Bombay, Maharashtra, India at 4 stations from an anchored ship. Power spectra were computed for selected lengths of records. Spectral energy...

  5. Power spectra of the angular fractals

    Science.gov (United States)

    Zhong, Xihua; Zhu, Yafen; Zhou, Yueming

    1993-09-01

    Based on the angular backbone taken from the triangular Sierpinski gasket, several seLf-similar structures are disigned, corresponding diffraction screens are made, and the Fraunhofer patterns as power spectra of them are given. Based upon a viewpoint of generative production and by means of the ui-branched displacement operation, we have found the recurrence formulae of spectral structure factor for these angular fractals. As a example, the recurrence formulae of power spectra for a coherent point group is given, corresponding a series of curves as well as an isogram are plotted. The analysis of result shows that the power spectra of this fractal point group has a rotation symmetry and a mirror symmetry, and appears a period doubling phenomenon which follows the process of generative production.

  6. Artificial intelligence analysis of paraspinal power spectra.

    Science.gov (United States)

    Oliver, C W; Atsma, W J

    1996-10-01

    OBJECTIVE: As an aid to discrimination of sufferers with back pain an artificial intelligence neural network was constructed to differentiate paraspinal power spectra. DESIGN: Clinical investigation using surface electromyography. METHOD: The surface electromyogram power spectra from 60 subjects, 33 non-back-pain sufferers and 27 chronic back pain sufferers were used to construct a back propagation neural network that was then tested. Subjects were placed on a test frame in 30 degrees of lumbar forward flexion. An isometric load of two-thirds maximum voluntary contraction was held constant for 30 s whilst surface electromyograms were recorded at the level of the L(4-5). Paraspinal power spectra were calculated and loaded into the input layer of a three-layer back propagation network. The neural network classified the spectra into normal or back pain type. RESULTS: The back propagation neural was shown to have satisfactory convergence with a specificity of 79% and a sensitivity of 80%. CONCLUSIONS: Artificial intelligence neural networks appear to be a useful method of differentiating paraspinal power spectra in back-pain sufferers.

  7. Inflationary power spectra with quantum holonomy corrections

    CERN Document Server

    Mielczarek, Jakub

    2013-01-01

    In this paper we study slow-roll inflation with holonomy corrections from loop quantum cosmology. Both tensor and scalar power spectra of primordial perturbations are computed up to the first order in slow-roll parameters and $V/\\rho_{c}$, where $V$ is a potential of the scalar field and $\\rho_{c}$ is a critical energy density (expected to be of the order of the Planck energy density). Possible normalizations of modes at short scales are discussed. In case the normalization is performed with use of the Wronskian condition applied to adiabatic vacuum, the tensor and scalar spectral indices are not quantum corrected in the leading order. However, by choosing an alternative method of normalization one can obtain quantum corrections in the leading order. Furthermore, we show that the holonomy-corrected equation of motion for tensor modes can be derived from an effective background metric. This allows us to prove that the Wronskian normalization condition for the tensor modes preserves the classical form.

  8. Meson Spectra: Power Law Potential Model in the Dirac Equation ...

    African Journals Online (AJOL)

    A single mass-spectra potential model has been used to predict the spectra of both light and heavy mesons (including leptonic decay-widths) in the Dirac equation. In fact a power law potential has been proposed with effective power where is the mass of the constituent quarks (in GeV) of the mesons considered.

  9. How to measure CMB polarization power spectra without losing information

    OpenAIRE

    Tegmark, Max; de Oliveira-Costa, Angelica

    2000-01-01

    We present a method for measuring CMB polarization power spectra given incomplete sky coverage and test it with simulated examples such as Boomerang 2001 and MAP. By augmenting the quadratic estimator method with an additional step, we find that the E and B power spectra can be effectively disentangled on angular scales substantially smaller than the width of the sky patch in the narrowest direction. We find that the basic quadratic and maximum-likelihood methods display a unneccesary sensiti...

  10. Cosmological flux noise and measured noise power spectra in SQUIDs.

    Science.gov (United States)

    Beck, Christian

    2016-06-20

    The understanding of the origin of 1/f magnetic flux noise commonly observed in superconducting devices such as SQUIDs and qubits is still a major unsolved puzzle. Here we discuss the possibility that a significant part of the observed low-frequency flux noise measured in these devices is ultimately seeded by cosmological fluctuations. We consider a theory where a primordial flux noise field left over in unchanged form from an early inflationary or quantum gravity epoch of the universe intrinsically influences the phase difference in SQUIDs and qubits. The perturbation seeds generated by this field can explain in a quantitatively correct way the form and amplitude of measured low-frequency flux noise spectra in SQUID devices if one takes as a source of fluctuations the primordial power spectrum of curvature fluctuations as measured by the Planck collaboration. Our theoretical predictions are in excellent agreement with recent low-frequency flux noise measurements of various experimental groups. Magnetic flux noise, so far mainly considered as a nuisance for electronic devices, may thus contain valuable information about fluctuation spectra in the very early universe.

  11. Analysis of the experimental positron lifetime spectra by neural networks

    Directory of Open Access Journals (Sweden)

    Avdić Senada

    2003-01-01

    Full Text Available This paper deals with the analysis of experimental positron lifetime spectra in polymer materials by using various algorithms of neural networks. A method based on the use of artificial neural networks for unfolding the mean lifetime and intensity of the spectral components of simulated positron lifetime spectra was previously suggested and tested on simulated data [Pžzsitetal, Applied Surface Science, 149 (1998, 97]. In this work, the applicability of the method to the analysis of experimental positron spectra has been verified in the case of spectra from polymer materials with three components. It has been demonstrated that the backpropagation neural network can determine the spectral parameters with a high accuracy and perform the decomposi-tion of lifetimes which differ by 10% or more. The backpropagation network has not been suitable for the identification of both the parameters and the number of spectral components. Therefore, a separate artificial neural network module has been designed to solve the classification problem. Module types based on self-organizing map and learning vector quantization algorithms have been tested. The learning vector quantization algorithm was found to have better performance and reliability. A complete artificial neural network analysis tool of positron lifetime spectra has been constructed to include a spectra classification module and parameter evaluation modules for spectra with a different number of components. In this way, both flexibility and high resolution can be achieved.

  12. Experimental spectra analysis in THM with the help of simulation based on Geant4 framework

    CERN Document Server

    Li, Chengbo; Zhou, Shuhua; Fu, Yuanyong; Zhou, Jing; Meng, Qiuying; Jiang, Zongjun; Wang, Xiaolian

    2014-01-01

    The Coulomb barrier and electron screening cause difficulties in directly measuring nuclear reaction cross sections of charged particles in astrophysical energies. The Trojan-horse method has been introduced to solve the difficulties as a powerful indirect tool. In order to understand experimental spectra better, Geant4 is employed to simulate the method for the first time. Validity and reliability of the simulation are examined by comparing the experimental data with simulated results. The Geant4 simulation can give useful information to understand the experimental spectra better in data analysis and is beneficial to the design for future related experiments.

  13. Power spectra for laser-extinction measurements.

    Science.gov (United States)

    Lacaze, B; Chabert, M

    2006-06-26

    Recent laser technology provides accurate measures of the dynamics of fluids and embedded particles. For instance, the laser-extinction measurements (LEM) uses a laser beam passing across the fluid and measures the residual laser light intensity at the fluid output. The particle concentration is estimated from this measurement. However, the particle flow is submitted to random time-varying fluctuations. This study thus proposes to model the received intensity by an appropriate random process. This paper first models the particle flow by a queueing process. Second, the measured intensity power spectrum is derived according to this random model. Finally, the simple case of a constant particle velocity is developped. The proposed model allows to generalize results previously obtained in the litterature with simplified models. Moreover, the particle celerity estimate is provided.

  14. Information rates and power spectra of digital codes

    DEFF Research Database (Denmark)

    Justesen, Jørn

    1982-01-01

    is expressed in terms of the rate distortion function for a memoryless finite alphabet source and mean-square error distortion measure. A class of simple dc-free power spectra is considered in detail, and a method for constructing Markov sources with such spectra is derived. It is found that these sequences......The encoding of independent data symbols as a sequence of discrete amplitude, real variables with given power spectrum is considered. The maximum rate of such an encoding is determined by the achievable entropy of the discrete sequence with the given constraints. An upper bound to this entropy...... have greater entropies than most codes with similar spectra that have been suggested earlier, and that they often come close to the upper bound. When the constraint on the power spectrum is replaced by a constraint On the variance of the sum of the encoded symbols, a stronger upper bound to the rate...

  15. Estimation of burst-mode LDA power spectra

    DEFF Research Database (Denmark)

    Velte, Clara Marika; George, William K.; Buchhave, Preben

    2014-01-01

    The estimation of power spectra from LDA data provides signal processing challenges for fluid dynamicists for several reasons: acquisition is dictated by randomly arriving particles, the registered particle velocities tend to be biased toward higher values, and the signal is highly intermittent...

  16. Polarized Power Spectra from HERA-19 Commissioning Data: Instrument Stability

    Science.gov (United States)

    Fox Fortino, Austin; Chichura, Paul; Igarashi, Amy; Kohn, Saul; Aguirre, James; HERA Collaboration

    2018-01-01

    The Epoch of Reionization (EoR) is a key period in the universe’s history, containing the formation of the first galaxies and large scale structures. Foreground emission is the limiting factor in detecting the 21 cm emission from the Epoch of Reionization (EoR). The HERA-19 low frequency radio interferometer aims to reduce the obfuscation from the foreground emission with its dish shaped antennae. We generate polarized 2D (cylindrically averaged) power spectra from seven days of observation from the HERA-19 2016 observation season in each of the four Stokes parameters I, Q, U, and V. These power spectra serve as a potent diagnostic tool that allow us to understand the instrument stability by comparison between nominally redundant baselines, and between observations of nominally the same astrophysical sky on successive days. The power spectra are expected to vary among nominally redundant measurements due to ionosphere fluctuations and thermal changes in the electronics and instrument beam patterns, as well as other factors. In this work we investigate the stability over time of these polarized power spectra, and use them to quantify the variation due to these effects.

  17. Planck 2013 results. XV. CMB power spectra and likelihood

    CERN Document Server

    Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Gaier, T.C.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Heraud, Y.; Gjerlow, E.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, T.R.; Jaffe, A.H.; Jewell, J.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kiiveri, K.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Laureijs, R.J.; Lawrence, C.R.; Le Jeune, M.; Leach, S.; Leahy, J.P.; Leonardi, R.; Leon-Tavares, J.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Lindholm, V.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Marinucci, D.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Millea, M.; Mitra, S.; Miville-Deschenes, M.A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Dwyer, I.J.; Orieux, F.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Paykari, P.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rahlin, A.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ringeval, C.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Sanselme, L.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Turler, M.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; White, M.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    We present the Planck likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations. We use this likelihood to derive the Planck CMB power spectrum over three decades in l, covering 2 = 50, we employ a correlated Gaussian likelihood approximation based on angular cross-spectra derived from the 100, 143 and 217 GHz channels. We validate our likelihood through an extensive suite of consistency tests, and assess the impact of residual foreground and instrumental uncertainties on cosmological parameters. We find good internal agreement among the high-l cross-spectra with residuals of a few uK^2 at l <= 1000. We compare our results with foreground-cleaned CMB maps, and with cross-spectra derived from the 70 GHz Planck map, and find broad agreement in terms of spectrum residuals and cosmological parameters. The best-fit LCDM cosmology is in excellent agreement with preliminary Planck polarisation spectra. The standard LCDM cosmology is well constrained b...

  18. Effect of microwave power on EPR spectra of natural and synthetic dental biocompatible materials

    Directory of Open Access Journals (Sweden)

    Adamczyk Jakub

    2015-07-01

    Full Text Available Paramagnetic centers in the two exemplary synthetic and natural dental biocompatible materials applied in implantology were examined by the use of an X-band (9.3 GHz electron paramagnetic resonance (EPR spectroscopy. The EPR spectra were measured in the range of microwave power 2.2–70 mW. The aims of this work were to compare paramagnetic centers concentrations in different dental biocompatible materials and to determine the effect of microwave power on parameters of their EPR spectra. It is the very first and innovatory examination of paramagnetic centers in these materials. It was pointed out that paramagnetic centers existed in both natural (~1018 spin/g and synthetic (~1019 spin/g dental biocompatible materials, but the lower free radical concentration characterized the natural sample. Continuous microwave saturation of EPR spectra indicated that faster spin-lattice relaxation processes existed in synthetic dental biocompatible materials than in natural material. Linewidths (ΔBpp of the EPR spectra of the natural dental material slightly increased for the higher microwave powers. Such effect was not observed for the synthetic material. The broad EPR lines (ΔBpp: 2.4 mT, 3.9 mT, were measured for the natural and synthetic dental materials, respectively. Probably strong dipolar interactions between paramagnetic centers in the studied samples may be responsible for their line broadening. EPR spectroscopy is the useful experimental method in the examination of paramagnetic centers in dental biocompatible materials.

  19. Analysis of polarized CMB power spectra using Gibbs Sampling.

    Science.gov (United States)

    Karki, Saket; Bunn, Emory

    2018-01-01

    The search for increasingly efficient techniques to produce pure E and B maps from polarization data with incomplete sky coverage has led to a general understanding of pure maps as Wiener-filtered polarization data. This framework can be further extended to Gibbs Sampling by using it as a technique to estimate the pure E and B mode spectra. As Gibbs sampling circumvents actual modes decomposition, it offers a potentially computationally less expensive method than traditional likelihood evaluation based methods. More importantly, Gibbs sampling addresses the problem of E mode contamination on B modes at high angular scales more naturally. A Wiener-filtered B map contains the least possible cross-contamination from the E component. We thus expect the B-mode spectra estimated using Gibbs sampling to be more accurate. We investigate the computational efficiency and accuracy of this method on large data sets. We also investigate if the estimated power spectrum is precise enough to be of practical use on real data in the future.

  20. Planck 2013 results. XV. CMB power spectra and likelihood

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Gaier, T. C.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kiiveri, K.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Laureijs, R. J.; Lawrence, C. R.; Le Jeune, M.; Leach, S.; Leahy, J. P.; Leonardi, R.; León-Tavares, J.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; Lindholm, V.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Marinucci, D.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Millea, M.; Mitra, S.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Orieux, F.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Paykari, P.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rahlin, A.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ringeval, C.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Sanselme, L.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; White, M.; White, S. D. M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    This paper presents the Planck 2013 likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations that accounts for all known relevant uncertainties, both instrumental and astrophysical in nature. We use this likelihood to derive our best estimate of the CMB angular power spectrum from Planck over three decades in multipole moment, ℓ, covering 2 ≤ ℓ ≤ 2500. The main source of uncertainty at ℓ ≲ 1500 is cosmic variance. Uncertainties in small-scale foreground modelling and instrumental noise dominate the error budget at higher ℓs. For ℓ < 50, our likelihood exploits all Planck frequency channels from 30 to 353 GHz, separating the cosmological CMB signal from diffuse Galactic foregrounds through a physically motivated Bayesian component separation technique. At ℓ ≥ 50, we employ a correlated Gaussian likelihood approximation based on a fine-grained set of angular cross-spectra derived from multiple detector combinations between the 100, 143, and 217 GHz frequency channels, marginalising over power spectrum foreground templates. We validate our likelihood through an extensive suite of consistency tests, and assess the impact of residual foreground and instrumental uncertainties on the final cosmological parameters. We find good internal agreement among the high-ℓ cross-spectra with residuals below a few μK2 at ℓ ≲ 1000, in agreement with estimated calibration uncertainties. We compare our results with foreground-cleaned CMB maps derived from all Planck frequencies, as well as with cross-spectra derived from the 70 GHz Planck map, and find broad agreement in terms of spectrum residuals and cosmological parameters. We further show that the best-fit ΛCDM cosmology is in excellent agreement with preliminary PlanckEE and TE polarisation spectra. We find that the standard ΛCDM cosmology is well constrained by Planck from the measurements at ℓ ≲ 1500. One specific example is the

  1. Efficient estimation of burst-mode LDA power spectra

    DEFF Research Database (Denmark)

    Velte, Clara Marika; George, William K

    2010-01-01

    and correlations is included, as well as one regarding the statistical convergence of the spectral estimator for random sampling. Further, the basic representation of the burst-mode LDA signal has been revisited due to observations in recent years of particles not following the flow (e.g., particle clustering......The estimation of power spectra from LDA data provides signal processing challenges for fluid dynamicists for several reasons. Acquisition is dictated by randomly arriving particles which cause the signal to be highly intermittent. This both creates self-noise and causes the measured velocities...... to be biased due to the statistical dependence on the velocity and when the particle arrives. This leads to incorrect moments when the data are evaluated by arithmetically averaging. The signal can be interpreted correctly, however, by applying residence time weighting to all statistics, which eliminates...

  2. Power spectrum of nuclear spectra with missing levels and mixed symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Molina, R.A. [Max-Planck-Institut fuer Physik Komplexer Systeme, Noethnitzer Str. 38, D-01187 Dresden (Germany) and Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain)]. E-mail: molina@iem.cfmac.csic.es; Retamosa, J. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Munoz, L. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Relano, A. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain); Faleiro, E. [Departamento de Fisica Aplicada, Universidad Politecnica de Madrid, E-28012 (Spain)

    2007-01-04

    Sequences of energy levels in nuclei are often plagued with missing levels whose number and position are unknown. It is also quite usual that all the quantum numbers of certain levels cannot be experimentally determined, and thus levels of different symmetries are mixed in the same sequence. The analysis of these imperfect spectra (from the point of view of spectral statistics) is unavoidable if one wants to extract some statistical information. The power spectrum of the {delta}{sub q} statistic has emerged in recent years as an important tool for the study of quantum chaos and spectral statistics. We derive analytical expressions for the observed power spectrum in terms of the fraction of observed levels and the number of mixed sequences. These expressions are tested with large shell model spectra simulating realistic experimental situations. A good estimation of the number of mixed symmetries and the fraction of missing levels is obtained by means of a least-squares fit in a wide set of different situations.

  3. Maturation of EEG Power Spectra in Early Adolescence: A Longitudinal Study

    Science.gov (United States)

    Cragg, Lucy; Kovacevic, Natasa; McIntosh, Anthony Randal; Poulsen, Catherine; Martinu, Kristina; Leonard, Gabriel; Paus, Tomas

    2011-01-01

    This study investigated the fine-grained development of the EEG power spectra in early adolescence, and the extent to which it is reflected in changes in peak frequency. It also sought to determine whether sex differences in the EEG power spectra reflect differential patterns of maturation. A group of 56 adolescents were tested at age 10 years and…

  4. Flow angle dependent photoacoustic Doppler power spectra under intensity-modulated continuous wave laser excitation

    Directory of Open Access Journals (Sweden)

    Yu Tong

    2016-02-01

    Full Text Available Photoacoustic Doppler (PAD power spectra showing an evident Doppler shift represent the major characteristics of the continuous wave-excited or burst wave-excited versions of PAD flow measurements. In this paper, the flow angle dependences of the PAD power spectra are investigated using an experiment setup that was established based on intensity-modulated continuous wave laser excitation. The setup has an overall configuration that is similar to a previously reported configuration, but is more sophisticated in that it accurately aligns the laser illumination with the ultrasound detection process, and in that it picks up the correct sample position. In the analysis of the power spectra data, we find that the background power spectra can be extracted by combining the output signals from the two channels of the lock-in amplifier, which is very useful for identification of the PAD power spectra. The power spectra are presented and analyzed in opposite flow directions, at different flow speeds, and at different flow angles. The power spectra at a 90° flow angle show the unique properties of symmetrical shapes due to PAD broadening. For the other flow angles, the smoothed power spectra clearly show a flow angle cosine relationship.

  5. Experimental Effects on IR Reflectance Spectra: Particle Size and Morphology

    Energy Technology Data Exchange (ETDEWEB)

    Beiswenger, Toya N.; Myers, Tanya L.; Brauer, Carolyn S.; Su, Yin-Fong; Blake, Thomas A.; Ertel, Alyssa B.; Tonkyn, Russell G.; Szecsody, James E.; Johnson, Timothy J.; Smith, Milton; Lanker, Cory

    2016-05-23

    For geologic and extraterrestrial samples it is known that both particle size and morphology can have strong effects on the species’ infrared reflectance spectra. Due to such effects, the reflectance spectra cannot be predicted from the absorption coefficients alone. This is because reflectance is both a surface as well as a bulk phenomenon, incorporating both dispersion as well as absorption effects. The same spectral features can even be observed as either a maximum or minimum. The complex effects depend on particle size and preparation, as well as the relative amplitudes of the optical constants n and k, i.e. the real and imaginary components of the complex refractive index. While somewhat oversimplified, upward-going amplitude in the reflectance spectrum usually result from surface scattering, i.e. rays that have been reflected from the surface without penetration, whereas downward-going peaks are due to either absorption or volume scattering, i.e. rays that have penetrated or refracted into the sample interior and are not reflected. While the effects are well known, we report seminal measurements of reflectance along with quantified particle size of the samples, the sizing obtained from optical microscopy measurements. The size measurements are correlated with the reflectance spectra in the 1.3 – 16 micron range for various bulk materials that have a combination of strong and weak absorption bands in order to understand the effects on the spectral features as a function of the mean grain size of the sample. We report results for both sodium sulfate Na2SO4 as well as ammonium sulfate (NH4)2SO4; the optical constants have been measured for (NH4)2SO4. To go a step further from the field to the laboratory we explore our understanding of particle size effects on reflectance spectra in the field using standoff detection. This has helped identify weaknesses and strengths in detection using standoff distances of up 160 meters away from the Target. The studies have

  6. A simplified method of estimating noise power spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, K.M.

    1998-12-01

    A technique to estimate the radial dependence of the noise power spectrum of images is proposed in which the calculations are conducted solely in the spatial domain of the noise image. The noise power spectrum averaged over a radial spatial-frequency interval is obtained form the variance of a noise image that has been convolved with a small kernel that approximates a Laplacian operator. Recursive consolidation of the image by factors of two in each dimension yields estimates of the noise power spectrum over that full range of spatial frequencies.

  7. Measuring Doppler-like power spectra and dermal perfusion using laser speckle contrast with multiple exposures

    Science.gov (United States)

    Thompson, O. B.; Andrews, M. K.

    2010-02-01

    Laser speckle contrast measurements provide effectively instantaneous maps of dermal perfusion, using easily obtainable hardware, but such maps are qualitative. Clinical applications of these techniques require a good theoretical and experimental foundation of understanding before relating them to a physiologically significant, quantitative perfusion value. We have confirmed that multiple-exposure laser speckle methods produce the same spectral information as laser Doppler measurements when applied to targets such as human tissue with embedded moving scatterers. This confirmation is based on both computer simulation of laser speckle data and experimental measurements on Brownian motion and skin perfusion using a laser Doppler system and a multiple-exposure laser speckle system. The Power Spectral Density (PSD) measurements of the light fluctuations derived using both techniques are equivalent. Dermal perfusion images can therefore be measured in exactly equivalent terms by either laser speckle contrast or more laborious scanning laser Doppler methods. Most analyses relating laser speckle contrast to perfusion depend on assuming a particular temporal autocorrelation function for the light intensity fluctuations in biospeckle. Using multiple-exposure laser speckle allows the autocorrelation function to be measured rather than assumed. Measured autocorrelation functions and their related power spectra for dermal perfusion are presented, including measurements under arterial occlusion to investigate a 'biological zero': the speckle blur relating to the remaining movement of tissue constituents when there is no net blood flow.

  8. Estimating Discrete Power Angular Spectra in Multiprobe OTA Setups

    DEFF Research Database (Denmark)

    Fan, Wei; Nielsen, Jesper Ødum; Pedersen, Gert Frølund

    2014-01-01

    The letter discusses over-the-air (OTA) testing for multiple-input–multiple-output (MIMO) capable terminals with emphasis on estimating discrete power angular spectrum modeled at the receiver (Rx) side in the test zone. Two techniques based on a uniform circular array (UCA) are proposed to obtain...... accurate direction-of-arrival estimates as well as power estimates of the impinging signals in the test zone. Simulation results match well with the target, as expected. Measurement results based on a virtual UCA in a practical 3-D multiprobe setup further support the simulation results. Possible reasons...... for the deviations between simulations and measurements are also investigated....

  9. Exponential power spectra, deterministic chaos and Lorentzian pulses in plasma edge dynamics

    Science.gov (United States)

    Maggs, J. E.; Morales, G. J.

    2012-12-01

    Exponential spectra have been observed in the edges of tokamaks, stellarators, helical devices and linear machines. The observation of exponential power spectra is significant because such a spectral character has been closely associated with the phenomenon of deterministic chaos by the nonlinear dynamics community. The proximate cause of exponential power spectra in both magnetized plasma edges and nonlinear dynamics models is the occurrence of Lorentzian pulses in the time signals of fluctuations. Lorentzian pulses are produced by chaotic behavior in the separatrix regions of plasma E × B flow fields or the limit cycle regions of nonlinear models. Chaotic advection, driven by the potential fields of drift waves in plasmas, results in transport. The observation of exponential power spectra and Lorentzian pulses suggests that fluctuations and transport at the edge of magnetized plasmas arise from deterministic, rather than stochastic, dynamics.

  10. Normalizations of High Taylor Reynolds Number Power Spectra

    Science.gov (United States)

    Puga, Alejandro; Koster, Timothy; Larue, John C.

    2014-11-01

    The velocity power spectrum provides insight in how the turbulent kinetic energy is transferred from larger to smaller scales. Wind tunnel experiments are conducted where high intensity turbulence is generated by means of an active turbulence grid modeled after Makita's 1991 design (Makita, 1991) as implemented by Mydlarski and Warhaft (M&W, 1998). The goal of this study is to document the evolution of the scaling region and assess the relative collapse of several proposed normalizations over a range of Rλ from 185 to 997. As predicted by Kolmogorov (1963), an asymptotic approach of the slope (n) of the inertial subrange to - 5 / 3 with increasing Rλ is observed. There are three velocity power spectrum normalizations as presented by Kolmogorov (1963), Von Karman and Howarth (1938) and George (1992). Results show that the Von Karman and Howarth normalization does not collapse the velocity power spectrum as well as the Kolmogorov and George normalizations. The Kolmogorov normalization does a good job of collapsing the velocity power spectrum in the normalized high wavenumber range of 0 . 0002 job in the normalized mid-wavenumber range of 15 University of California, Irvine Research Fund.

  11. ERRORS IN FREQUENCY PARAMETERS OF EMG POWER SPECTRA

    NARCIS (Netherlands)

    HOF, AL

    1991-01-01

    Frequency shifts in random signals, e.g., EMG or Doppler ultrasound, can be followed by monitoring one or more parameters of the power spectrum. When such a frequency parameter is determined over a finite length of the signal, a random error and sometimes a systematic error or bias are introduced.

  12. Comparison of power spectra for tomosynthesis projections and reconstructed images

    Energy Technology Data Exchange (ETDEWEB)

    Engstrom, Emma; Reiser, Ingrid; Nishikawa, Robert [Royal Institute of Technology, 11231 Stockholm (Sweden); Department of Radiology, University of Chicago, Chicago 60637 (United States)

    2009-05-15

    Burgess et al. [Med. Phys. 28, 419-437 (2001)] showed that the power spectrum of mammographic breast background follows a power law and that lesion detectability is affected by the power-law exponent {beta} which measures the amount of structure in the background. Following the study of Burgess et al., the authors measured and compared the power-law exponent of mammographic backgrounds in tomosynthesis projections and reconstructed slices to investigate the effect of tomosynthesis imaging on background structure. Our data set consisted of 55 patient cases. For each case, regions of interest (ROIs) were extracted from both projection images and reconstructed slices. The periodogram of each ROI was computed by taking the squared modulus of the Fourier transform of the ROI. The power-law exponent was determined for each periodogram and averaged across all ROIs extracted from all projections or reconstructed slices for each patient data set. For the projections, the mean {beta} averaged across the 55 cases was 3.06 (standard deviation of 0.21), while it was 2.87 (0.24) for the corresponding reconstructions. The difference in {beta} for a given patient between the projection ROIs and the reconstructed ROIs averaged across the 55 cases was 0.194, which was statistically significant (p<0.001). The 95% CI for the difference between the mean value of {beta} for the projections and reconstructions was [0.170, 0.218]. The results are consistent with the observation that the amount of breast structure in the tomosynthesis slice is reduced compared to projection mammography and that this may lead to improved lesion detectability.

  13. Distribution of Acoustic Power Spectra for an Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Kusyumov A.N.

    2016-01-01

    Full Text Available The broadband aerodynamic noise can be studied, assuming isotropic flow, turbulence and decay. Proudman’s approach allows practical calculations of noise based on CFD solutions of RANS or URANS equations at the stage of post processing and analysis of the solution. Another aspect is the broadband acoustic spectrum and the distribution of acoustic power over a range of frequencies. The acoustic energy spectrum distribution in isotropic turbulence is non monotonic and has a maximum at a certain value of Strouhal number. In the present work the value of acoustic power peak frequency is determined using a prescribed form of acoustic energy spectrum distribution presented in papers by S. Sarkar and M. Y. Hussaini and by G. M. Lilley. CFD modelling of the flow around isolated helicopter fuselage model was considered using the HMB CFD code and the RANS equations.

  14. Planck 2013 results. XV. CMB power spectra and likelihood

    OpenAIRE

    Planck collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoit, A.

    2013-01-01

    This paper presents the Planck 2013 likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations that accounts for all known relevant uncertainties, both instrumental and astrophysical in nature. We use this likelihood to derive our best estimate of the CMB angular power spectrum from Planck over three decades in multipole moment, ℓ, covering 2 ≤ ℓ ≤ 2500. The main source of uncertainty at ℓ ≲ 1500 is cosmic variance. Uncertainties i...

  15. Spherical Harmonic Analyses of Intensity Mapping Power Spectra

    Science.gov (United States)

    Liu, Adrian; Zhang, Yunfan; Parsons, Aaron R.

    2016-12-01

    Intensity mapping is a promising technique for surveying the large-scale structure of our universe from z = 0 to z ˜ 150, using the brightness temperature field of spectral lines to directly observe previously unexplored portions of our cosmic timeline. Examples of targeted lines include the 21 cm hyperfine transition of neutral hydrogen, rotational lines of carbon monoxide, and fine-structure lines of singly ionized carbon. Recent efforts have focused on detections of the power spectrum of spatial fluctuations, but have been hindered by systematics such as foreground contamination. This has motivated the decomposition of data into Fourier modes perpendicular and parallel to the line of sight, which has been shown to be a particularly powerful way to diagnose systematics. However, such a method is well-defined only in the limit of a narrow-field, flat-sky approximation. This limits the sensitivity of intensity mapping experiments, as it means that wide surveys must be separately analyzed as a patchwork of smaller fields. In this paper, we develop a framework for analyzing intensity mapping data in a spherical Fourier-Bessel basis, which incorporates curved sky effects without difficulty. We use our framework to generalize a number of techniques in intensity mapping data analysis from the flat sky to the curved sky. These include visibility-based estimators for the power spectrum, treatments of interloper lines, and the “foreground wedge” signature of spectrally smooth foregrounds.

  16. Modifications to cosmological power spectra from scalar-tensor entanglement and their observational consequences

    Energy Technology Data Exchange (ETDEWEB)

    Bolis, Nadia; Albrecht, Andreas [Department of Physics, University of California at Davis,One Shields Ave, Davis CA 95616 (United States); Holman, R. [Physics Department, Carnegie Mellon University,Pittsburgh, PA 15213 (United States); College of Computational Sciences, Minerva University,1145 Market Street, San Francisco, CA 94103 (United States)

    2016-12-06

    We consider the effects of entanglement in the initial quantum state of scalar and tensor fluctuations during inflation. We allow the gauge-invariant scalar and tensor fluctuations to be entangled in the initial state and compute modifications to the various cosmological power spectra. We compute the angular power spectra (C{sub l}’s) for some specific cases of our entangled state and discuss what signals one might expect to find in CMB data. This entanglement also can break rotational invariance, allowing for the possibility that some of the large scale anomalies in the CMB power spectrum might be explained by this mechanism.

  17. Temporal power spectra of irradiance scintillation for infrared optical waves' propagation through marine atmospheric turbulence.

    Science.gov (United States)

    Cui, Linyan

    2014-09-01

    Current theoretical temporal power spectra models of an optical wave have been developed for terrestrial environments. The interactions between humidity and temperature fluctuations in the marine atmospheric environments make the marine atmospheric turbulence particularly challenging, and the optical waves' propagation through marine turbulence exhibits a different behavior with respect to terrestrial propagation. In this paper, the temporal power spectra of irradiance scintillation under weak marine atmospheric turbulence, which is one of the key temporal statistics to describe the correlation of irradiance fluctuations at different time instances, is investigated in detail both analytically and numerically. Closed-form expressions for the temporal power spectra of irradiance scintillation are derived for infrared plane and spherical waves under weak marine atmospheric turbulence, and they consider physically the influences of finite turbulence inner and outer scales. The final results indicate that the marine atmospheric turbulence brings more effects on the irradiance scintillation than the terrestrial atmospheric turbulence.

  18. Fact versus formula in the power spectra of complex systems

    Science.gov (United States)

    Watkins, Nick

    2016-04-01

    More than 100 years ago, Thomson and Tait's classic "Treatise on Natural Philosophy" cautioned its readers against "considering the formula and not the fact as physical reality". Deciding what the facts actually _were, however, was left as an exercise for the reader ... Complex systems offer many examples [1] of the ambiguity Thomson and Tait were trying to point out. This presentation will be about a formula-the "1/f" spectral shape seen in many areas of physics including climate science; and an empirical fact-the growth of rescaled range originally seen in river time series and now known as the Hurst effect. It is well known that Mandelbrot kicked off the study of long range dependence (LRD) in the mid 1960s [2] with a stationary model for 1/f noise and the Hurst effect. This fractional Gaussian model is now so well known that it is often seen as synonymous with both 1/f noise and the Hurst effect. However Mandelbrot himself was aware that there were other models that produced 1/f noise, including a family [3-6] which he called "conditionally stationary", with power law distributions of times between switching of states. Late in his life he re-emphasised the clear contrasts between their behaviour and that of fGn. I will explain why these other models are also physically interesting, and will show why real systems including climate examples may potentially map more closely to one or the other, or may in fact combine both aspects. I will also discuss his proposals for distinguishing between the models and how they may be implemented. [1] Watkins, Bunched Black Swans, Geophys Res. Lett, 2013 [2] Graves et al, A Brief History of Long Memory, arXiv:1406.6018 [stat.OT] [3] Berger and Mandelbrot, "A New Model for Error Clustering in Telephone Circuits", IBM Technical Journal, July 1963. [4] Mandelbrot, "Self-similar error clusters in communications systems, and the concept of conditional stationarity", IEEE Trans. on Communications Technology, COM-13, 71-90, 1965. [5

  19. H I anisotropies associated with radio-polarimetric filaments . Steep power spectra associated with cold gas

    Science.gov (United States)

    Kalberla, P. M. W.; Kerp, J.; Haud, U.; Haverkorn, M.

    2017-10-01

    Context. LOFAR detected toward 3C 196 linear polarization structures which were found subsequently to be closely correlated with cold filamentary H I structures. The derived direction-dependent H I power spectra revealed marked anisotropies for narrow ranges in velocity, sharing the orientation of the magnetic field as expected for magneto-hydrodynamical (MHD) turbulence. Aims: Using the Galactic portion of the Effelsberg-Bonn H I Survey (EBHIS) we continue our study of such anisotropies in the H I distribution in direction of two WSRT fields, Horologium and Auriga; both are well known for their prominent radio-polarimetric depolarization canals. At 349 MHz the observed pattern in total intensity is insignificant but polarized intensity and polarization angle show prominent ubiquitous structures with so far unknown origin. Methods: Apodizing the H I survey data by applying a rotational symmetric 50% Tukey window, we derive average and position angle dependent power spectra. We fit power laws and characterize anisotropies in the power distribution. We used a Gaussian analysis to determine relative abundances for the cold and warm neutral medium. Results: For the analyzed radio-polarimetric targets significant anisotropies are detected in the H I power spectra; their position angles are aligned to the prominent depolarization canals, initially detected by WSRT. H I anisotropies are associated with steep power spectra. Steep power spectra, associated with cold gas, are detected also in other fields. Conclusions: Radio-polarimetric depolarization canals are associated with filamentary H I structures that belong to the cold neutral medium (CNM). Anisotropies in the CNM are in this case linked to a steepening of the power-spectrum spectral index, indicating that phase transitions in a turbulent medium occur on all scales. Filamentary H I structures, driven by thermal instabilities, and radio-polarimetric filaments are associated with each other. The magneto-ionic medium

  20. Test spectra experimental construction for evaluating gamma-spectrometry computer codes for the 235U determination

    Directory of Open Access Journals (Sweden)

    Karfopoulos Konstantinos L.

    2014-01-01

    Full Text Available The determination of 235U in environmental samples from its 185.72 keV photons may require the deconvolution of the multiplet photopeak at ~186 keV, due to the co-existence of the 186.25 keV photons of 226Ra in the spectrum. Successful deconvolution depends on many parameters, such as the detector characteristics, the activity concentration of the 235U and 226Ra in the sample, the background continuum in the 186 keV energy region and the gamma-spectrometry computer code used. In this work two sets of experimental test spectra were constructed for examining the deconvolution of the multiplet photopeak performed by different codes. For the construction of the test spectra, a high-resolution low energy germanium detector was used. The first series consists of 140 spectra and simulates environmental samples containing various activity concentration levels of 235U and 226Ra. The second series consists of 280 spectra and has been derived by adding 137Cs, corresponding to various activity concentration levels, to specific first series test spectra. As the 137Cs backscatter edge is detected in the energy region of the multiplet photopeak at ~186 keV, this second series of test spectra tests the analysis of the multiplet photopeak in high background continuum conditions. The analysis of the test spectra is performed by two different g-spectrometry analysis codes: (a spectrum unix analysis code, a computer code developed in-house and (b analysis of germanium detector spectra, a program freely available from the IAEA. The results obtained by the two programs are compared in terms of photopeak detection and photopeak area determination.

  1. Relaxation and power spectra of low-frequency fluctuations in foams

    Science.gov (United States)

    Reshetnikov, A. V.; Skokov, V. N.; Koverda, V. P.

    2012-11-01

    The dynamics of foam formation in a water-glycerin solution was studied to establish the relationship between the relaxation characteristics and the fluctuation power spectrum for a stochastic process. Foaming occurred during the dissociation of the gas-saturated solution and during bubbling of the solution through a porous filter. Two types of relaxation of the foam—exponential and power-law—were revealed. The power-law type of relaxation was observed upon exposure to ultrasound. Relationships between the type of relaxation and the distribution of lowfrequency fluctuations and power spectra was established.

  2. Calculated and experimental low-loss electron energy loss spectra of dislocations in diamond and GaN

    CERN Document Server

    Jones, R; Gutiérrez-Sosa, A; Bangert, U; Heggie, M I; Blumenau, A T; Frauenheim, T; Briddon, P R

    2002-01-01

    First-principles calculations of electron energy loss (EEL) spectra for bulk GaN and diamond are compared with experimental spectra acquired with a scanning tunnelling electron microscope offering ultra-high-energy resolution in low-loss energy spectroscopy. The theoretical bulk low-loss EEL spectra, in the E sub g to 10 eV range, are in good agreement with experimental data. Spatially resolved spectra from dislocated regions in both materials are distinct from bulk spectra. The main effects are, however, confined to energy losses lying above the band edge. The calculated spectra for low-energy dislocations in diamond are consistent with the experimental observations, but difficulties remain in understanding the spectra of threading dislocations in GaN.

  3. Experimental performance of a thermoelectric power generator

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, J.R.; Santos, L.P.; Silva, J.M.; Silva, R.E. [University of Taubate (UNITAU), SP (Brazil). Mechanical Engineering Dept.

    2009-07-01

    It is known that reversible thermal and electrical effects can be detected in a circuit consisting on two similar semiconductor material having their junctions at different temperatures. This phenomenon, called Seebeck effect and Peltier effect, can be used to generate electric power and cooling. The Seebeck effect was first observed by the physician Thomas Johann Seebeck, in 1821, when he was studying thermoelectric phenomenon, and it consists in the production of an electric power between two semiconductors joint of semiconductor material, when they are submitted to different temperatures. The thermoelectric modules are made of several thermoelectric pairs made of semiconductors materials joined in series and sealed between two surfaces of ceramic, one covers the hot joins and the other covers the cold ones, through which a continuous current flows and, according to its way, one board becomes hot or cold, and the dissipated power is a function of the electric current flowing through the module. This research presents, initially, the theoretical equations which allow evaluating the thermoelectric modules' performance applied to electric power generation and the experimental results of this elements association. During tests there were used an electrical resistance as heat source, thermocouples to evaluate the temperatures in the thermoelectric module's heat and cold sides, thermo anemometers to measure the air speed and temperature measurements in the heat sink and a software to obtain, store and analyze the data. The main objective is to know the behavior of the most important design parameters that are the efficiency and the electric power generated by the thermoelectric system. (author)

  4. Important influence of respiration on human R-R interval power spectra is largely ignored

    Science.gov (United States)

    Brown, T. E.; Beightol, L. A.; Koh, J.; Eckberg, D. L.

    1993-01-01

    Frequency-domain analyses of R-R intervals are used widely to estimate levels of autonomic neural traffic to the human heart. Because respiration modulates autonomic activity, we determined for nine healthy subjects the influence of breathing frequency and tidal volume on R-R interval power spectra (fast-Fourier transform method). We also surveyed published literature to determine current practices in this burgeoning field of scientific inquiry. Supine subjects breathed at rates of 6, 7.5, 10, 15, 17.1, 20, and 24 breaths/min and with nominal tidal volumes of 1,000 and 1,500 ml. R-R interval power at respiratory and low (0.06-0.14 Hz) frequencies declined significantly as breathing frequency increased. R-R interval power at respiratory frequencies was significantly greater at a tidal volume of 1,500 than 1,000 ml. Neither breathing frequency nor tidal volume influenced average R-R intervals significantly. Our review of studies reporting human R-R interval power spectra showed that 51% of the studies controlled respiratory rate, 11% controlled tidal volume, and 11% controlled both respiratory rate and tidal volume. The major implications of our analyses are that breathing parameters strongly influence low-frequency as well as respiratory frequency R-R interval power spectra and that this influence is largely ignored in published research.

  5. Experimental determination of excitonic band structures of single-walled carbon nanotubes using circular dichroism spectra.

    Science.gov (United States)

    Wei, Xiaojun; Tanaka, Takeshi; Yomogida, Yohei; Sato, Naomichi; Saito, Riichiro; Kataura, Hiromichi

    2016-10-05

    Experimental band structure analyses of single-walled carbon nanotubes have not yet been reported, to the best of our knowledge, except for a limited number of reports using scanning tunnelling spectroscopy. Here we demonstrate the experimental determination of the excitonic band structures of single-chirality single-walled carbon nanotubes using their circular dichroism spectra. In this analysis, we use gel column chromatography combining overloading selective adsorption with stepwise elution to separate 12 different single-chirality enantiomers. Our samples show higher circular dichroism intensities than the highest values reported in previous works, indicating their high enantiomeric purity. Excitonic band structure analysis is performed by assigning all observed Eii and Eij optical transitions in the circular dichroism spectra. The results reproduce the asymmetric structures of the valence and conduction bands predicted by density functional theory. Finally, we demonstrate that an extended empirical formula can estimate Eij optical transition energies for any (n,m) species.

  6. Unfolding linac photon spectra and incident electron energies from experimental transmission data, with direct independent validation.

    Science.gov (United States)

    Ali, E S M; McEwen, M R; Rogers, D W O

    2012-11-01

    In a recent computational study, an improved physics-based approach was proposed for unfolding linac photon spectra and incident electron energies from transmission data. In this approach, energy differentiation is improved by simultaneously using transmission data for multiple attenuators and detectors, and the unfolding robustness is improved by using a four-parameter functional form to describe the photon spectrum. The purpose of the current study is to validate this approach experimentally, and to demonstrate its application on a typical clinical linac. The validation makes use of the recent transmission measurements performed on the Vickers research linac of National Research Council Canada. For this linac, the photon spectra were previously measured using a NaI detector, and the incident electron parameters are independently known. The transmission data are for eight beams in the range 10-30 MV using thick Be, Al and Pb bremsstrahlung targets. To demonstrate the approach on a typical clinical linac, new measurements are performed on an Elekta Precise linac for 6, 10 and 25 MV beams. The different experimental setups are modeled using EGSnrc, with the newly added photonuclear attenuation included. For the validation on the research linac, the 95% confidence bounds of the unfolded spectra fall within the noise of the NaI data. The unfolded spectra agree with the EGSnrc spectra (calculated using independently known electron parameters) with RMS energy fluence deviations of 4.5%. The accuracy of unfolding the incident electron energy is shown to be ∼3%. A transmission cutoff of only 10% is suitable for accurate unfolding, provided that the other components of the proposed approach are implemented. For the demonstration on a clinical linac, the unfolded incident electron energies and their 68% confidence bounds for the 6, 10 and 25 MV beams are 6.1 ± 0.1, 9.3 ± 0.1, and 19.3 ± 0.2 MeV, respectively. The unfolded spectra for the clinical linac agree with the

  7. Cloud 3D Effects Evidenced in Landsat Power Spectra and Autocorrelation Functions

    Science.gov (United States)

    Oreopoulos, Lazaros; Marshak, Alexander; Cahalan, Robert F.; Wen, Guoyong

    1999-01-01

    An analysis of nadir reflectivity Fourier spatial power spectra and autocorrelation functions at solar wavelengths and for cloudy conditions has been carried out. The data come from Landsat Thematic Mapper (TM) observations, while Monte Carlo (MC) simulations are used to aid the interpretation of the Landsat results. We show that radiative processes produce consistent signatures on power spectra and autocorrelation functions. The former take a variety of forms not shown or explained in previous observational studies. We demonstrate that the TM spectra can potentially be affected by both radiative "roughening" at intermediate scales (approx. 1 -5 km), being more prevalent at large solar zenith angles, and the already documented radiative "smoothing" at small scales (less than 1 km). These processes are wavelength dependent, as shown by systematic differences between conservative (for cloud droplets) TM band 4 (approx. 0.8 microns) and absorbing band 7 (approx. 2.2 microns): band 7 exhibits more roughening and less smoothing. This is confirmed quantitatively by comparing least-squared fitted power spectral slopes for the two bands. It is also corroborated by a slower decrease with distance of autocorrelation function values for band 4 compared to band 7. The appearance of roughening at large solar zenith angles is a result of side illumination and shadowing and adds an additional complexity to the power spectra. MC spectra are useful in illustrating that scale invariant optical depth fields can produce complex power spectra that take a variety of shapes under different conditions. We show that radiative roughening increases with the decrease of single scattering albedo and with the increase of solar zenith angle (as in the observations). For high Sun there is also a clear shift of the radiative smoothing scale to smaller values as droplet absorption increases. The shape of the power spectrum is sensitive to the magnitude and type of cloud top height variability, with

  8. Quantum theory and experimental studies of absorption spectra and photoisomerization of azobenzene polymers

    DEFF Research Database (Denmark)

    Pedersen, Thomas Garm; Ramanujam, P.S.; Johansen, P.M.

    1998-01-01

    The microscopic properties of azobenzene chromophores are important for a correct description of optical storage systems based on photoinduced anisotropy in azobenzene polymers. A quantum model of these properties is presented and verified by comparison to experimental absorption spectra for trans...... and cis isomers of cyano methoxy azobenzene. In addition, the trans --> cis quantum efficiency is measured, and hence the combined experimental and theoretical work allows one to determine the essential molecular properties, including magnitude and anisotropy of the absorption cross section and various...

  9. Benzthiazoline-2-thione (BTT) revisited: An experimental and theoretical endeavor to understand UV-spectra

    Science.gov (United States)

    Bandyopadhyay, Prasanta; Bhattacharya, Barnali; Majhi, Koushik; Majee, Prakash; Sarkar, Utpal; Motin Seikh, Md.

    2017-10-01

    Benzthiazoline-2-thione (BTT) and its derivatives are industrially and biologically important heterocyclic organic compounds. Here, we present both experimental and theoretical investigations. The IR and UV spectroscopic measurements unambiguously show the keto-enol tautomerization. Here, for the first time we report spectral changes of BTT in different solvents using quantum chemical calculations and hence reproduce both the hypsochromic and bathochromic shifts in the UV spectra which are sensitive to the nature of hydrogen bonding between solvent and BTT. Our calculations also reveal that the lowest energy transition is associated with a π → π∗ rather than a n → π∗ transition suggested to explain experimental results.

  10. On the causes of spectral enhancements in solar wind power spectra

    Science.gov (United States)

    Unti, T.; Russell, C. T.

    1976-01-01

    Enhancements in power spectra of the solar-wind ion flux in the frequency neighborhood of 0.5 Hz had been noted by Unti et al. (1973). It was speculated that these were due to convected small-scale density irregularities. In this paper, 54 flux spectra calculated from OGO 5 data are examined. It is seen that the few prominent spectral peaks which occur were not generated by density irregularities, but were due to several different causes, including convected discontinuities and propagating transverse waves. A superposition of many spectra, however, reveals a moderate enhancement at a frequency corresponding to convected features with a correlation length of a proton gyroradius, consistent with the results of Neugebauer (1975).

  11. Dynamical dark energy simulations: high accuracy power spectra at high redshift

    Energy Technology Data Exchange (ETDEWEB)

    Casarini, Luciano; Bonometto, Silvio A. [Department of Physics G. Occhialini-Milano-Bicocca University, Piazza della Scienza 3, 20126 Milano (Italy); Maccio, Andrea V., E-mail: luciano.casarini@mib.infn.it, E-mail: maccio@mpia.de, E-mail: silvio.bonometto@mib.infn.it [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany)

    2009-03-15

    Accurate predictions on non-linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes, so obtaining key information on Dark Energy nature. This calls for high precision simulations, covering the whole functional space of w(z) state equations and taking also into account the admitted ranges of other cosmological parameters; surely a difficult task. A procedure was however suggested, able to match the spectra at z = 0, up to k {approx} 3 hMpc{sup -1}, in cosmologies with an (almost) arbitrary w(z), by making recourse to the results of N-body simulations with w = const. In this paper we extend such procedure to high redshift and test our approach through a series of N-body gravitational simulations of various models, including a model closely fitting WMAP5 and complementary data. Our approach detects w = const. models, whose spectra meet the requirement within 1% at z = 0 and perform even better at higher redshift, where they are close to a permil precision. Available Halofit expressions, extended to (constant) w{ne}-1 are unfortunately unsuitable to fit the spectra of the physical models considered here. Their extension to cover the desired range should be however feasible, and this will enable us to match spectra from any DE state equation.

  12. A Comparison of Maps and Power Spectra Determined from South Pole Telescope and Planck Data

    Science.gov (United States)

    Hou, Z.; Aylor, K.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H.-M.; Chown, R.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W. B.; Follin, B.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Omori, Y.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2018-01-01

    We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the Planck satellite over the patch of sky covered by the SPT-SZ survey. We first visually compare the maps and find that the residuals appear consistent with noise after accounting for differences in angular resolution and filtering. We then calculate (1) the cross-spectrum between two independent halves of SPT data, (2) the cross-spectrum between two independent halves of Planck data, and (3) the cross-spectrum between SPT and Planck data. We find that the three cross-spectra are well fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free calibration parameter—i.e., we find no evidence for systematic errors in either data set. As a by-product, we improve the precision of the SPT calibration by nearly an order of magnitude, from 2.6% to 0.3% in power. Finally, we compare all three cross-spectra to the full-sky Planck power spectrum and find marginal evidence for differences between the power spectra from the SPT-SZ footprint and the full sky. We model these differences as a power law in spherical harmonic multipole number. The best-fit value of this tilt is consistent among the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt is a sample variance fluctuation in the SPT-SZ region relative to the full sky. The consistency of cosmological parameters derived from these data sets is discussed in a companion paper.

  13. Uplink Array Calibration via Power Spectra in the Presence of Phase and Delay Errors

    Science.gov (United States)

    Vilnrotter, V. A.

    2017-08-01

    In uplink array operations, alignment of the carrier phase and modulation delay from each antenna is of fundamental importance in achieving maximum array gain. The power spectrum of the combined signal can be obtained at the spacecraft and relayed to the ground for processing, or in near-Earth radar applications the echo signals from small targets can be collected and processed at the ground receiver. Expressions are derived for the power spectrum of a transmitting array of K elements in the presence of phase and delay alignment errors, and simulation results are provided to validate the theoretical results. It is shown that the power spectra are generally sensitive to errors in carrier and modulation alignment, thus enabling uplink array calibration directly from the power spectrum of the combined array signal.

  14. Spectral-statistics properties of the experimental and theoretical light meson spectra

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, L., E-mail: laura@nuc5.fis.ucm.es [European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), Villa Tambosi, Strada delle Tabarelle 286, Villazzano, I-38123 (Italy); Fernandez-Ramirez, C., E-mail: cesar@nuc2.fis.ucm.es [European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), Villa Tambosi, Strada delle Tabarelle 286, Villazzano, I-38123 (Italy); Grupo de Fisica Nuclear, Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Relano, A., E-mail: armando.relano@gmail.com [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, E-28006 Madrid (Spain); Departamento de Fisica Aplicada I, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Retamosa, J. [Grupo de Fisica Nuclear, Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain)

    2012-03-29

    We present a robust analysis of the spectral fluctuations exhibited by the light meson spectrum. This analysis provides information about the degree of chaos in light mesons and may be useful to get some insight on the underlying interactions. Our analysis unveils that the statistical properties of the light meson spectrum are close, but not exactly equal, to those of chaotic systems. In addition, we have analyzed several theoretical spectra including the latest lattice QCD calculation. With a single exception, their statistical properties are close to those of a generic integrable system, and thus incompatible with the experimental spectrum.

  15. Molecular structure refinement by direct fitting of atomic coordinates to experimental ESR spectra

    CERN Document Server

    Charnock, G T P; Kuprov, Ilya

    2011-01-01

    An attempt is made to bypass spectral analysis and fit internal coordinates of radicals directly to experimental liquid- and solid-state electron spin resonance (ESR) spectra. We take advantage of the recently introduced large-scale spin dynamics simulation algorithms and of the fact that the accuracy of quantum mechanical calculations of ESR parameters has improved to the point of quantitative correctness. Partial solutions are offered to the local minimum problem in spectral fitting and to the problem of spin interaction parameters (hyperfine couplings, chemical shifts, etc.) being very sensitive to distortions in molecular geometry.

  16. Forward Modeling of Reduced Power Spectra From Three-Dimensional $\\mathbf{k}$-Space

    CERN Document Server

    von Papen, Michael

    2015-01-01

    We present results from a numerical forward model to evaluate one-dimensional reduced power spectral densities (PSD) from arbitrary energy distributions in $\\mathbf{k}$-space. In this model, we can separately calculate the diagonal elements of the spectral tensor for incompressible axisymmetric turbulence with vanishing helicity. Given a critically balanced turbulent cascade with $k_\\|\\sim k_\\perp^\\alpha$ and $\\alpha<1$, we explore the implications on the reduced PSD as a function of frequency. The spectra are obtained under the assumption of Taylor's hypothesis. We further investigate the functional dependence of the spectral index $\\kappa$ on the field-to-flow angle $\\theta$ between plasma flow and background magnetic field from MHD to electron kinetic scales. We show that critically balanced turbulence asymptotically develops toward $\\theta$-independent spectra with a slope corresponding to the perpendicular cascade. This occurs at a transition frequency $f_{2D}(L,\\alpha,\\theta)$, which is analytically ...

  17. Musical rhythm spectra from Bach to Joplin obey a 1/f power law.

    Science.gov (United States)

    Levitin, Daniel J; Chordia, Parag; Menon, Vinod

    2012-03-06

    Much of our enjoyment of music comes from its balance of predictability and surprise. Musical pitch fluctuations follow a 1/f power law that precisely achieves this balance. Musical rhythms, especially those of Western classical music, are considered highly regular and predictable, and this predictability has been hypothesized to underlie rhythm's contribution to our enjoyment of music. Are musical rhythms indeed entirely predictable and how do they vary with genre and composer? To answer this question, we analyzed the rhythm spectra of 1,788 movements from 558 compositions of Western classical music. We found that an overwhelming majority of rhythms obeyed a 1/f(β) power law across 16 subgenres and 40 composers, with β ranging from ∼0.5-1. Notably, classical composers, whose compositions are known to exhibit nearly identical 1/f pitch spectra, demonstrated distinctive 1/f rhythm spectra: Beethoven's rhythms were among the most predictable, and Mozart's among the least. Our finding of the ubiquity of 1/f rhythm spectra in compositions spanning nearly four centuries demonstrates that, as with musical pitch, musical rhythms also exhibit a balance of predictability and surprise that could contribute in a fundamental way to our aesthetic experience of music. Although music compositions are intended to be performed, the fact that the notated rhythms follow a 1/f spectrum indicates that such structure is no mere artifact of performance or perception, but rather, exists within the written composition before the music is performed. Furthermore, composers systematically manipulate (consciously or otherwise) the predictability in 1/f rhythms to give their compositions unique identities.

  18. From the Cover: Musical rhythm spectra from Bach to Joplin obey a 1/f power law

    Science.gov (United States)

    Levitin, Daniel J.; Chordia, Parag; Menon, Vinod

    2012-03-01

    Much of our enjoyment of music comes from its balance of predictability and surprise. Musical pitch fluctuations follow a 1/f power law that precisely achieves this balance. Musical rhythms, especially those of Western classical music, are considered highly regular and predictable, and this predictability has been hypothesized to underlie rhythm's contribution to our enjoyment of music. Are musical rhythms indeed entirely predictable and how do they vary with genre and composer? To answer this question, we analyzed the rhythm spectra of 1,788 movements from 558 compositions of Western classical music. We found that an overwhelming majority of rhythms obeyed a 1/fβ power law across 16 subgenres and 40 composers, with β ranging from ∼0.5-1. Notably, classical composers, whose compositions are known to exhibit nearly identical 1/f pitch spectra, demonstrated distinctive 1/f rhythm spectra: Beethoven's rhythms were among the most predictable, and Mozart's among the least. Our finding of the ubiquity of 1/f rhythm spectra in compositions spanning nearly four centuries demonstrates that, as with musical pitch, musical rhythms also exhibit a balance of predictability and surprise that could contribute in a fundamental way to our aesthetic experience of music. Although music compositions are intended to be performed, the fact that the notated rhythms follow a 1/f spectrum indicates that such structure is no mere artifact of performance or perception, but rather, exists within the written composition before the music is performed. Furthermore, composers systematically manipulate (consciously or otherwise) the predictability in 1/f rhythms to give their compositions unique identities.

  19. Angpow: a software for the fast computation of accurate tomographic power spectra

    Science.gov (United States)

    Campagne, J.-E.; Neveu, J.; Plaszczynski, S.

    2017-06-01

    Aims: The statistical distribution of galaxies is a powerful probe to constrain cosmological models and gravity. In particular, the matter power spectrum P(k) provides information about the cosmological distance evolution and the galaxy clustering. However the building of P(k) from galaxy catalogs requires a cosmological model to convert angles on the sky and redshifts into distances, which leads to difficulties when comparing data with predicted P(k) from other cosmological models, and for photometric surveys like the Large Synoptic Survey Telescope (LSST). The angular power spectrum Cℓ(z1,z2) between two bins located at redshift z1 and z2 contains the same information as the matter power spectrum, and is free from any cosmological assumption, but the prediction of Cℓ(z1,z2) from P(k) is a costly computation when performed precisely. Methods: The Angpow software aims at quickly and accurately computing the auto (z1 = z2) and cross (z1 ≠ z2) angular power spectra between redshift bins. We describe the developed algorithm based on developments on the Chebyshev polynomial basis and on the Clenshaw-Curtis quadrature method. We validate the results with other codes, and benchmark the performance. Results: Angpow is flexible and can handle any user-defined power spectra, transfer functions, and redshift selection windows. The code is fast enough to be embedded inside programs exploring large cosmological parameter spaces through the Cℓ(z1,z2) comparison with data. We emphasize that the Limber's approximation, often used to speed up the computation, gives incorrect Cℓ values for cross-correlations. The C++ code is available from http://https://gitlab.in2p3.fr/campagne/AngPow

  20. The acute effects of alcohol on sleep electroencephalogram power spectra in late adolescence.

    Science.gov (United States)

    Chan, Julia K M; Trinder, John; Colrain, Ian M; Nicholas, Christian L

    2015-02-01

    Alcohol's effect on sleep electroencephalogram (EEG) power spectra during late adolescence is of interest given that this age group shows both dramatic increases in alcohol consumption and major sleep-related developmental changes in quantitative EEG measures. This study examined the effect of alcohol on sleep EEG power spectra in 18- to 21-year-old college students. Participants were 24 (12 female) healthy 18- to 21-year-old social drinkers. Participants underwent 2 conditions: presleep alcohol and placebo, followed by standard polysomnography with comprehensive EEG recordings. After alcohol, mean breath alcohol concentration at lights-out was 0.084%. Interaction effects indicated simultaneous increases in frontal non-rapid eye movement sleep (NREM) delta (p = 0.031) and alpha (p = 0.005) power in the first sleep cycles following alcohol consumption which was most prominent at frontal scalp sites (p power (p = 0.001) was also observed after alcohol. As hypothesized, alcohol increased slow wave sleep-related NREM delta power. However, there was a simultaneous increase in frontal alpha power. Results suggest that alcohol may exert an arousal influence which may compete with the sleep maintenance influence of increased delta activity. The phenomenon is similar to, or the same as, alpha-delta sleep which has been associated with the presence of disruptive stimuli during sleep. This may have negative implications for the impact of presleep alcohol consumption on sleep and consequent daytime functioning. Copyright © 2015 by the Research Society on Alcoholism.

  1. Protonation effects on the UV/Vis absorption spectra of imatinib: a theoretical and experimental study.

    Science.gov (United States)

    Grante, Ilze; Actins, Andris; Orola, Liana

    2014-08-14

    An experimental and theoretical investigation of protonation effects on the UV/Vis absorption spectra of imatinib showed systematic changes of absorption depending on the pH, and a new absorption band appeared below pH 2. These changes in the UV/Vis absorption spectra were interpreted using quantum chemical calculations. The geometry of various imatinib cations in the gas phase and in ethanol solution was optimized with the DFT/B3LYP method. The resultant geometries were compared to the experimentally determined crystal structures of imatinib salts. The semi-empirical ZINDO-CI method was employed to calculate the absorption lines and electronic transitions. Our study suggests that the formation of the extra near-UV absorption band resulted from an increase of imatinib trication concentration in the solution, while the rapid increase of the first absorption maximum could be attributed to both the formation of imatinib trication and tetracation. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. A Comparison of Maps and Power Spectra Determined from South Pole Telescope and Planck Data

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Z.; et al.

    2017-04-04

    We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the \\textit{Planck} satellite over the 2540 $\\text{deg}^2$ patch of sky covered by the SPT-SZ survey. We first visually compare the maps and find that the map residuals appear consistent with noise after we account for differences in angular resolution and filtering. To make a more quantitative comparison, we calculate (1) the cross-spectrum between two independent halves of SPT 150 GHz data, (2) the cross-spectrum between two independent halves of \\textit{Planck} 143 GHz data, and (3) the cross-spectrum between SPT 150 GHz and \\textit{Planck} 143 GHz data. We find the three cross-spectra are well-fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free parameter characterizing the relative calibration between the two. As a by-product of this analysis, we improve the calibration of SPT data by nearly an order of magnitude, from 2.6\\% to 0.3\\% in power; the best-fit power calibration factor relative to the most recent published SPT calibration is $1.0174 \\pm 0.0033$. Finally, we compare all three cross-spectra to the full-sky \\textit{Planck} $143 \\times 143$ power spectrum and find a hint ($\\sim$1.5$\\sigma$) for differences in the power spectrum of the SPT-SZ footprint and the full-sky power spectrum, which we model and fit as a power law in the spectrum. The best-fit value of this tilt is consistent between the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt---assuming it is real---is a sample variance fluctuation in the SPT-SZ region relative to the full sky. Despite the precision of our tests, we find no evidence for systematic errors in either data set. The consistency of cosmological parameters derived from these datasets is discussed in a companion paper.

  3. Modification of EEG power spectra and EEG connectivity in autobiographical memory: a sLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Brunetti, Riccardo; Farina, Benedetto; Speranza, Anna Maria; Losurdo, Anna; Testani, Elisa; Contardi, Anna; Della Marca, Giacomo

    2014-08-01

    The aim of the present study was to explore the modifications of scalp EEG power spectra and EEG connectivity during the autobiographical memory test (AM-T) and during the retrieval of an autobiographical event (the high school final examination, Task 2). Seventeen healthy volunteers were enrolled (9 women and 8 men, mean age 23.4 ± 2.8 years, range 19-30). EEG was recorded at baseline and while performing the autobiographical memory (AM) tasks, by means of 19 surface electrodes and a nasopharyngeal electrode. EEG analysis was conducted by means of the standardized LOw Resolution Electric Tomography (sLORETA) software. Power spectra and lagged EEG coherence were compared between EEG acquired during the memory tasks and baseline recording. The frequency bands considered were as follows: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta1 (13-17.5 Hz); beta2 (18-30 Hz); gamma (30.5-60 Hz). During AM-T, we observed a significant delta power increase in left frontal and midline cortices (T = 3.554; p < 0.05) and increased EEG connectivity in delta band in prefrontal, temporal, parietal, and occipital areas, and for gamma bands in the left temporo-parietal regions (T = 4.154; p < 0.05). In Task 2, we measured an increased power in the gamma band located in the left posterior midline areas (T = 3.960; p < 0.05) and a significant increase in delta band connectivity in the prefrontal, temporal, parietal, and occipital areas, and in the gamma band involving right temporo-parietal areas (T = 4.579; p < 0.05). These results indicate that AM retrieval engages in a complex network which is mediated by both low- (delta) and high-frequency (gamma) EEG bands.

  4. First experimental prompt γ-ray spectra in fast neutron-induced fission of 238U

    Directory of Open Access Journals (Sweden)

    Laborie J.-M.

    2017-01-01

    Full Text Available The knowledge of prompt fission γ-ray emission has been of major interest in reactor physics since few years, but it is also important in the understanding of the fission process. We present here measurements of prompt γ-ray spectra emitted in the fission of 238U. A simple experimental method was used to measure the prompt fission gamma-ray spectrum up to 10 MeV. In this approach, the gamma-rays are measured with a bismuth germanate (BGO detector which offers two significant advantages with respect to other gamma-ray detectors: a high peak-to-total ratio and a high efficiency. The prompt fission neutrons are rejected by the time-of-flight technique between the BGO detector and a fission trigger given by a fission chamber. Prompt fission gamma-ray spectra were measured for 1.7, 5.2 and 15.6 MeV incoming neutron energies at the CEA, DAM, DIF Van de Graaff accelerator.

  5. Bargaining Power in Relational Contracts: An Experimental Study

    OpenAIRE

    Cordero Salas, Paula

    2011-01-01

    This paper provides experimental evidence of the economic impact from shifting bargaining power in relational contracts. I implement an experimental design that adjusts the bargaining power of sellers (agents) and the enforceability of the contract. I find that the vast majority of contracts take the form of efficiency wage contracts instead of contingent performance contracts when enforcement is partially incomplete and sellers have more bargaining power than buyers. The total contracted and...

  6. Origin of multiple periodicities in the Fourier power spectra of the Plasmodium falciparum genome

    Directory of Open Access Journals (Sweden)

    Nunes Miriam CS

    2011-12-01

    Full Text Available Abstract Background Fourier transforms and their associated power spectra are used for detecting periodicities and protein-coding genes and is generally regarded as a well established technique. Many of the periodicities which have been found with this method are quite well understood such as the periodicity of 3 nt which is associated to codon usage. But what is the origin of the peculiar frequency multiples k/21 which were reported for a tiny section of chromosome 2 in P. falciparum? Are these present in other chromosomes and perhaps in related organisms? And how should we interpret fractional periodicities in genomes? Results We applied the binary indicator power spectrum to all chromosomes of P. falciparum, and found that the frequency overtones k/21 are present only in non-coding sections. We did not find such frequency overtones in any other related genomes. Furthermore, the frequency overtones were identified as artifacts of the way the genome is encoded into a numerical sequence, that is, they are frequency aliases. By choosing a different way to encode the sequence the overtones do not appear. In view of these results, we revisited early applications of this technique to proteins where frequency overtones were reported. Conclusions Some authors hinted recently at the possibility of mapping artifacts and frequency aliases in power spectra. However, in the case of P. falciparum the frequency aliases are particularly strong and can mask the 1/3 frequency which is used for gene detecting. This shows that albeit being a well known technique, with a long history of application in proteins, few researchers seem to be aware of the problems represented by frequency aliases.

  7. Theoretical and experimental study of the electronic states and spectra of KBi and KSb

    Science.gov (United States)

    Setzer, K. D.; Fink, E. H.; Alekseyev, A. B.; Liebermann, H.-P.; Buenker, R. J.

    2017-03-01

    Gas phase emission spectra of the hitherto unknown free radicals KBi and KSb were measured in the NIR range with a Fourier-transform spectrometer. The emissions were observed from a fast-flow system in which bismuth or antimony vapor in argon carrier gas was passed through a microwave discharge and mixed with potassium vapor in an observation tube. For KBi, two systems of blue-degraded bands observed in the range 5800-7700 cm-1 are assigned to the transitions A3Π (A20+) → X3Σ-(X10+, X21). Nine bands of the A20+ → X10+ and three bands of the A20+ → X21 system were measured at high spectral resolution and rotationally analysed. The rotational and vibrational analyses yielded the spectroscopic parameters of the X10+, X21, and A20+ states. For KSb, in the range of the sensitive Ge detector, only one sequence of bands was measured near 6880 cm-1. By analogy with the previously observed spectra of NaSb and NaAs these bands were identified to be the Δv = 0 sequence of the a2 → X21 transition of KSb. Some very weak bands observed at low resolution in the range 3800-5200 cm-1 are assigned to the transitions A3Π (A21) → X3Σ -(X10+, X21). To aid in the analysis of the experimental data, a series of relativistic configuration interaction calculations has been carried out to obtain potential energy curves for the low-lying states of KBi and KSb, vibrational constants, equilibrium internuclear distances, and also electric dipole transition moments connecting the states.

  8. A direct measurement of tomographic lensing power spectra from CFHTLenS

    Science.gov (United States)

    Köhlinger, F.; Viola, M.; Valkenburg, W.; Joachimi, B.; Hoekstra, H.; Kuijken, K.

    2016-02-01

    We measure the weak gravitational lensing shear power spectra and their cross-power in two photometric redshift bins from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). The measurements are performed directly in multipole space in terms of adjustable band powers. For the extraction of the band powers from the data we have implemented and extended a quadratic estimator, a maximum likelihood method that allows us to readily take into account irregular survey geometries, masks, and varying sampling densities. We find the 68 per cent credible intervals in the σ8-Ωm plane to be marginally consistent with results from Planck for a simple five-parameter Λ cold dark matter (ΛCDM) model. For the projected parameter S8 ≡ σ8(Ωm/0.3)0.5 we obtain a best-fitting value of S_8 = 0.768_{-0.039}^{+0.045}. This constraint is consistent with results from other CFHTLenS studies as well as the Dark Energy Survey. Our most conservative model, including modifications to the power spectrum due to baryon feedback and marginalization over photometric redshift errors, yields an upper limit on the total mass of three degenerate massive neutrinos of Σmν < 4.53 eV at 95 per cent credibility, while a Bayesian model comparison does not favour any model extension beyond a simple five-parameter ΛCDM model. Combining the shear likelihood with Planck breaks the σ8-Ωm degeneracy and yields σ8 = 0.818 ± 0.013 and Ωm = 0.300 ± 0.011 which is fully consistent with results from Planck alone.

  9. Cosmological nonlinear density and velocity power spectra including nonlinear vector and tensor modes

    Science.gov (United States)

    Hwang, Jai-chan; Jeong, Donghui; Noh, Hyerim

    2016-06-01

    We present the leading order nonlinear density and velocity power spectra in the complete form; previous studies have omitted the vector- and tensor-type perturbations simultaneously excited by the scalar-type perturbation in nonlinear order. These additional contributions are comparable to the scalar-type purely relativistic perturbations, and thus negligible in the current paradigm of concordance cosmology: concerning density and velocity perturbations of the pressureless matter in perturbation regime well inside of matter-dominated epoch, we show that pure Einstein's gravity contributions appearing from the third order are entirely negligible (five orders of magnitude smaller than the Newtonian contributions) in all scales. We thus prove that Newtonian perturbation theory is quite reliable in calculating the amplitude of matter fluctuations even in the precision era of cosmology. Therefore, the only relativistic effect relevant for interpreting observational data must be the projection effects that occurs when mapping galaxies onto the observed coordinate.

  10. Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters

    CERN Document Server

    Aghanim, N.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chiang, H.C.; Christensen, P.R.; Clements, D.L.; Colombo, L.P.L.; Combet, C.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Desert, F.X.; Di Valentino, E.; Dickinson, C.; Diego, J.M.; Dolag, K.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Gerbino, M.; Giard, M.; Gjerlow, E.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hamann, J.; Hansen, F.K.; Harrison, D.L.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Holmes, W.A.; Hornstrup, A.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kiiveri, K.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Le Jeune, M.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P.B.; Lilley, M.; Linden-Vornle, M.; Lindholm, V.; Lopez-Caniego, M.; Macias-Perez, J.F.; Maffei, B.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Meinhold, P.R.; Melchiorri, A.; Migliaccio, M.; Millea, M.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J.A.; Narimani, A.; Naselsky, P.; Nati, F.; Natoli, P.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T.J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G.W.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rossetti, M.; Roudier, G.; d'Orfeuil, B.Rouille; Rubino-Martin, J.A.; Rusholme, B.; Salvati, L.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Serra, P.; Spencer, L.D.; Spinelli, M.; Stolyarov, V.; Stompor, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-01-01

    This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlation functions of CMB temperature and polarization. They use the hybrid approach employed previously: pixel-based at low multipoles, $\\ell$, and a Gaussian approximation to the distribution of cross-power spectra at higher $\\ell$. The main improvements are the use of more and better processed data and of Planck polarization data, and more detailed foreground and instrumental models. More than doubling the data allows further checks and enhanced immunity to systematics. Progress in foreground modelling enables a larger sky fraction, contributing to enhanced precision. Improvements in processing and instrumental models further reduce uncertainties. Extensive tests establish robustness and accuracy, from temperature, from polarization, and from their combination, and show that the {\\Lambda}CDM model continues to offer a very good fit. We further validate the likelihood against specific extensions to this baseline, suc...

  11. Parametric and experimental analysis using a power flow approach

    Science.gov (United States)

    Cuschieri, J. M.

    1990-01-01

    A structural power flow approach for the analysis of structure-borne transmission of vibrations is used to analyze the influence of structural parameters on transmitted power. The parametric analysis is also performed using the Statistical Energy Analysis approach and the results are compared with those obtained using the power flow approach. The advantages of structural power flow analysis are demonstrated by comparing the type of results that are obtained by the two analytical methods. Also, to demonstrate that the power flow results represent a direct physical parameter that can be measured on a typical structure, an experimental study of structural power flow is presented. This experimental study presents results for an L shaped beam for which an available solution was already obtained. Various methods to measure vibrational power flow are compared to study their advantages and disadvantages.

  12. MCNPCX calculations of dose rates and spectra in experimental channels of the CTEx irradiating facility

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Renato G.; Rebello, Wilson F.; Vellozo, Sergio O.; Junior, Luis M., E-mail: renatoguedes@ime.eb.br, E-mail: rebello@ime.eb.br, E-mail: vellozo@cbpf.br, E-mail: luisjrmoreira@hotmail.com [Instituto Militar de Engenharia (IME), Janeiro, RJ (Brazil); Vital, Helio C., E-mail: vital@ctex.eb.br [Centro Tecnologico do Exercito (CTEx), Barra de Guaratiba, RJ (Brazil); Rusin, Tiago, E-mail: tiago.rusin@mma.gov.br [Ministerio do Meio Ambiente, Brasilia, DF (Brazil); Silva, Ademir X., E-mail: ademir@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    MCNPX simulations have been performed in order to calculate dose rates as well as spectra along the four experimental channels of the gamma irradiating facility at the Technology Center of the Brazilian Army (CTEx). Safety, operational and research requirements have led to the need to determine both the magnitude and spectra of the leaking gamma fluxes. The CTEx experimental facility is cavity type with a moveable set of 28 horizontally positioned rods, filled with Cesium-137 chloride and doubly encased in stainless steel that yields an approximately plane 42 kCi-source that provides a maximum dose rate of about 1.5 kG/h into two irradiating chambers. The channels are intended for irradiation tests outside facility. They would allow larger samples to be exposed to lower gamma dose rates under controlled conditions. Dose rates have been calculated for several positions inside the channels as well as at their exits. In addition, for purposes related to the safety of operators and personnel, the angles submitted by the exiting beams have also been evaluated as they spread when leaving the channels. All calculations have been performed by using a computational model of the CTEx facility that allows its characteristics and operation to be accurately simulated by using the Monte Carlo Method. Virtual dosimeters filled with Fricke (ferrous sulfate) were modeled and positioned throughout 2 vertical channels (top and bottom) and 2 horizontal ones (front and back) in order to map dose rates and gamma spectrum distributions. The calculations revealed exiting collimated beams in the order of tenths of Grays per minute as compared to the maximum 25 Gy / min dose rate in the irradiator chamber. In addition, the beams leaving the two vertical channels were found to exhibit a widespread cone-shaped distribution with aperture angle ranging around 85 deg. The data calculated in this work are intended for use in the design of optimized experiments (better positioning of samples and

  13. Experimental and theoretical studies on IR, Raman, and UV-Vis spectra of quinoline-7-carboxaldehyde.

    Science.gov (United States)

    Kumru, M; Küçük, V; Kocademir, M; Alfanda, H M; Altun, A; Sarı, L

    2015-01-05

    Spectroscopic properties of quinoline-7-carboxaldehyde (Q7C) have been studied in detail both experimentally and theoretically. The FT-IR (4000-50 cm(-1)), FT-Raman (4000-50 cm(-1)), dispersive-Raman (3500-50 cm(-1)), and UV-Vis (200-400 nm) spectra of Q7C were recorded at room temperature (25 °C). Geometry parameters, potential energy surface about CCH(O) bond, harmonic vibrational frequencies, IR and Raman intensities, UV-Vis spectrum, and thermodynamic characteristics (at 298.15K) of Q7C were computed at Hartree-Fock (HF) and density functional B3LYP levels employing the 6-311++G(d,p) basis set. Frontier molecular orbitals, molecular electrostatic potential, and Mulliken charge analyses of Q7C have also been performed. Q7C has two stable conformers that are energetically very close to each other with slight preference to the conformer that has oxygen atom of the aldehyde away from the nitrogen atom of the quinoline. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Can arousing feedback rectify lapses in driving? Prediction from EEG power spectra

    Science.gov (United States)

    Lin, Chin-Teng; Huang, Kuan-Chih; Chuang, Chun-Hsiang; Ko, Li-Wei; Jung, Tzyy-Ping

    2013-10-01

    Objective. This study explores the neurophysiological changes, measured using an electroencephalogram (EEG), in response to an arousing warning signal delivered to drowsy drivers, and predicts the efficacy of the feedback based on changes in the EEG. Approach. Eleven healthy subjects participated in sustained-attention driving experiments. The driving task required participants to maintain their cruising position and compensate for randomly induced lane deviations using the steering wheel, while their EEG and driving performance were continuously monitored. The arousing warning signal was delivered to participants who experienced momentary behavioral lapses, failing to respond rapidly to lane-departure events (specifically the reaction time exceeded three times the alert reaction time). Main results. The results of our previous studies revealed that arousing feedback immediately reversed deteriorating driving performance, which was accompanied by concurrent EEG theta- and alpha-power suppression in the bilateral occipital areas. This study further proposes a feedback efficacy assessment system to accurately estimate the efficacy of arousing warning signals delivered to drowsy participants by monitoring the changes in their EEG power spectra immediately thereafter. The classification accuracy was up 77.8% for determining the need for triggering additional warning signals. Significance. The findings of this study, in conjunction with previous studies on EEG correlates of behavioral lapses, might lead to a practical closed-loop system to predict, monitor and rectify behavioral lapses of human operators in attention-critical settings.

  15. Default Mode Network alterations in alexithymia: an EEG power spectra and connectivity study

    Science.gov (United States)

    Imperatori, Claudio; Della Marca, Giacomo; Brunetti, Riccardo; Carbone, Giuseppe Alessio; Massullo, Chiara; Valenti, Enrico Maria; Amoroso, Noemi; Maestoso, Giulia; Contardi, Anna; Farina, Benedetto

    2016-01-01

    Recent neuroimaging studies have shown that alexithymia is characterized by functional alterations in different brain areas [e.g., posterior cingulate cortex (PCC)], during emotional/social tasks. However, only few data are available about alexithymic cortical networking features during resting state (RS). We have investigated the modifications of electroencephalographic (EEG) power spectra and EEG functional connectivity in the default mode network (DMN) in subjects with alexithymia. Eighteen subjects with alexithymia and eighteen subjects without alexithymia matched for age and gender were enrolled. EEG was recorded during 5 min of RS. EEG analyses were conducted by means of the exact Low Resolution Electric Tomography software (eLORETA). Compared to controls, alexithymic subjects showed a decrease of alpha power in the right PCC. In the connectivity analysis, compared to controls, alexithymic subjects showed a decrease of alpha connectivity between: (i) right anterior cingulate cortex and right PCC, (ii) right frontal lobe and right PCC, and (iii) right parietal lobe and right temporal lobe. Finally, mediation models showed that the association between alexithymia and EEG connectivity values was directed and was not mediated by psychopathology severity. Taken together, our results could reflect the neurophysiological substrate of some core features of alexithymia, such as the impairment in emotional awareness. PMID:27845326

  16. Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters

    Science.gov (United States)

    Planck Collaboration; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombo, L. P. L.; Combet, C.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Di Valentino, E.; Dickinson, C.; Diego, J. M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Gerbino, M.; Giard, M.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hamann, J.; Hansen, F. K.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Holmes, W. A.; Hornstrup, A.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kiiveri, K.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P. B.; Lilley, M.; Linden-Vørnle, M.; Lindholm, V.; López-Caniego, M.; Macías-Pérez, J. F.; Maffei, B.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Meinhold, P. R.; Melchiorri, A.; Migliaccio, M.; Millea, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Mottet, S.; Munshi, D.; Murphy, J. A.; Narimani, A.; Naselsky, P.; Nati, F.; Natoli, P.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rossetti, M.; Roudier, G.; Rouillé d'Orfeuil, B.; Rubiño-Martín, J. A.; Rusholme, B.; Salvati, L.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Serra, P.; Spencer, L. D.; Spinelli, M.; Stolyarov, V.; Stompor, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, F.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-09-01

    This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlationfunctions of the cosmic microwave background (CMB) temperature and polarization fluctuations that account for relevant uncertainties, both instrumental and astrophysical in nature. They are based on the same hybrid approach used for the previous release, I.e., a pixel-based likelihood at low multipoles (ℓ< 30) and a Gaussian approximation to the distribution of cross-power spectra at higher multipoles. The main improvements are the use of more and better processed data and of Planck polarization information, along with more detailed models of foregrounds and instrumental uncertainties. The increased redundancy brought by more than doubling the amount of data analysed enables further consistency checks and enhanced immunity to systematic effects. It also improves the constraining power of Planck, in particular with regard to small-scale foreground properties. Progress in the modelling of foreground emission enables the retention of a larger fraction of the sky to determine the properties of the CMB, which also contributes to the enhanced precision of the spectra. Improvements in data processing and instrumental modelling further reduce uncertainties. Extensive tests establish the robustness and accuracy of the likelihood results, from temperature alone, from polarization alone, and from their combination. For temperature, we also perform a full likelihood analysis of realistic end-to-end simulations of the instrumental response to the sky, which were fed into the actual data processing pipeline; this does not reveal biases from residual low-level instrumental systematics. Even with the increase in precision and robustness, the ΛCDM cosmological model continues to offer a very good fit to the Planck data. The slope of the primordial scalar fluctuations, ns, is confirmed smaller than unity at more than 5σ from Planck alone. We further validate the robustness of the

  17. Power spectra of ionospheric scintillations obtained from observations of Cygnus A on the radio telescope URAN-4

    Science.gov (United States)

    Panishko, S. K.; Litvinenko, O. A.; Kravetz, R. O.

    2006-10-01

    There are many records of Cygnus A passages through the direction pattern obtained on the radio telescope URAN-4 during 1998-2004. Most of these show fluctuations in the flux density caused by ionospheric scintillations. The power spectrum is an important characteristic of the stochastic process and such processes are the main reason for the nature of scintillations. In this paper, estimations of the power spectra of ionospheric scintillations are made from the observations of Cyg A on the radio telescope URAN-4. Examples of the spectra are presented for observations under different circumstances and for several scintillation activity levels.

  18. EXPERIMENTAL INVESTIGATION OF AN AIR CHARGED LOW POWERED STIRLING ENGINE

    Directory of Open Access Journals (Sweden)

    Can ÇINAR

    2004-01-01

    Full Text Available In this study, an air charged, low powered manufactured ? type Stirling engine was investigated experimentally. Tests were conducted at 800, 900 and 1000 °C hot source temperatures, 1, 1.5, 2, 2.5, 3, 3.5 bars air charge pressure. The variation of engine power depending on the charge pressure and hot source temperature for two different heat transfer area was investigated experimentally. Maximum output power was obtained at 1000 °C and 3 bars charge pressure as 58 W at 441 rpm. Engine speed was reached at 846 rpm without load.

  19. Modeling the complexity of acoustic emission during intermittent plastic deformation: Power laws and multifractal spectra

    Science.gov (United States)

    Kumar, Jagadish; Ananthakrishna, G.

    2018-01-01

    Scale-invariant power-law distributions for acoustic emission signals are ubiquitous in several plastically deforming materials. However, power-law distributions for acoustic emission energies are reported in distinctly different plastically deforming situations such as hcp and fcc single and polycrystalline samples exhibiting smooth stress-strain curves and in dilute metallic alloys exhibiting discontinuous flow. This is surprising since the underlying dislocation mechanisms in these two types of deformations are very different. So far, there have been no models that predict the power-law statistics for discontinuous flow. Furthermore, the statistics of the acoustic emission signals in jerky flow is even more complex, requiring multifractal measures for a proper characterization. There has been no model that explains the complex statistics either. Here we address the problem of statistical characterization of the acoustic emission signals associated with the three types of the Portevin-Le Chatelier bands. Following our recently proposed general framework for calculating acoustic emission, we set up a wave equation for the elastic degrees of freedom with a plastic strain rate as a source term. The energy dissipated during acoustic emission is represented by the Rayleigh-dissipation function. Using the plastic strain rate obtained from the Ananthakrishna model for the Portevin-Le Chatelier effect, we compute the acoustic emission signals associated with the three Portevin-Le Chatelier bands and the Lüders-like band. The so-calculated acoustic emission signals are used for further statistical characterization. Our results show that the model predicts power-law statistics for all the acoustic emission signals associated with the three types of Portevin-Le Chatelier bands with the exponent values increasing with increasing strain rate. The calculated multifractal spectra corresponding to the acoustic emission signals associated with the three band types have a maximum

  20. Cusp-latitude Pc3 spectra: band-limited and power-law components

    Directory of Open Access Journals (Sweden)

    P. V. Ponomarenko

    Full Text Available This work attempts to fill a gap in comparative studies of upstream-generated Pc3–4 waves and broad band ULF noise observed at cusp latitudes. We performed a statistical analysis of the spectral properties of three years of cusp-latitude ground magnetometer data, finding that the average daytime Pc3–4 spectra are characterized by two principal components: an upstream-related band-limited enhancement (‘signal’ and a power-law background (‘noise’ with S(f a  f -4 . Based on this information we developed an algorithm allowing for the deconvolution of these two components in the spectral domain. The frequency of the signal enhancement increases linearly with IMF magnitude as f [mHz] ~ 4.4 | BIMF | [nT], and its power maximizes around IMF cone angles qxB ~ 20 and 160° and at 10:30–11:00 MLT. Both spectral components exhibit similar semiannual variations with equinoctial maxima. The back-ground noise power grows with increasing southward Bz and remains nearly constant for northward Bz . Its diurnal variation resembles that of Pc5 field-line resonance power, with a maximum near 09:00 MLT. Both the band-limited signal and broad band noise components show power-law growth with solar wind velocity a V 5.71sw and a V 4.12sw, respectively. Thus, the effective signal-to-noise ratio increases with in-creasing Vsw. The observations suggest that the noise generation is associated with reconnection processes.

    Key words. Magnetospheric physics (magnetopause, cusp, and boundary layers; MHD waves and instabilities; solar wind magnetosphere interactions

  1. Signatures of X-ray reverberation in the power spectra of AGN

    Science.gov (United States)

    Papadakis, I.; Pecháček, T.; Dovčiak, M.; Epitropakis, A.; Emmanoulopoulos, D.; Karas, V.

    2016-04-01

    Aims: We study the effects of X-ray reprocessing in the power spectra (PSDs) of active galactic nuclei (AGNs). Methods: We compute fully relativistic disc response functions in the case of lamp-post geometry using the full observed reflection spectrum for various X-ray source heights, disc inclination, and spin values of the central black hole. Since the observed PSD is equal to the product of the intrinsic power spectrum with the transfer function (I.e. the Fourier transform of the disc response function), we are able to predict the observed PSDs in the case of X-ray illumination of the inner disc. Results: The observed PSD should show a prominent dip at high frequencies and an oscillatory behaviour with a decreasing amplitude at higher frequencies. The reverberation echo features should be more prominent in energy bands where the reflection component is more pronounced. The frequency of the dip is independent of energy, and it is mainly determined by the black hole mass and the X-ray source height. The amplitude of the dip increases with increasing black hole spin and inclination angle, as long as the height of the lamp is smaller than ~10 gravitational radii. Conclusions: The detection of the X-ray reverberation signals in the PSDs can provide further evidence for X-ray illumination of the inner disc in AGN. Our results are largely independent of the assumed geometry of the disc-corona system, as long as it does not change with time, and the disc response function is characterized by a sharp rise, a plateau, and a decline at longer times. Irrespective of the geometry, the frequency of the main dip should decrease with increasing mean time of the response function, and the amplitude of the dip should increase with increasing reflection fraction.

  2. EEG theta and beta power spectra in adolescents with ADHD versus adolescents with ASD + ADHD.

    Science.gov (United States)

    Bink, M; van Boxtel, G J M; Popma, A; Bongers, I L; Denissen, A J M; van Nieuwenhuizen, Ch

    2015-08-01

    Attention problems are common in youngsters with attention deficit hyperactivity disorder (ADHD) as well as in adolescents with combined autism spectrum disorder (ASD) and ADHD. However, it is unknown whether there is psychophysiological overlap and/or a difference in electroencephalogram (EEG) power spectra between ADHD and comorbid ASD and ADHD (ASD + ADHD), on and off stimulant medication. To explore potential differences and overlap, measures of theta and beta power in adolescents diagnosed with ADHD (n = 33) versus adolescents with combined ASD + ADHD (n = 20), categorized by stimulant medication use (57 % of the total sample), were compared. EEG measures were acquired in three conditions: (1) resting state, eyes closed (2) resting state, eyes open and (3) during an oddball task. In addition, performance on the d2 attention test was analyzed. Adolescents with ADHD displayed more absolute theta activity than adolescents with ASD + ADHD during the eyes open and task conditions, independent of stimulant medication use. In addition, only the adolescents with ADHD showed an association between diminished attention test performance and increased theta in the eyes open condition. Results of the current study suggest that although there is behavioral overlap between ADHD characteristics in adolescents with ADHD and adolescents with combined ASD + ADHD, the underlying psychophysiological mechanisms may be different. Adolescents with ASD + ADHD exhibited fewer of the EEG physiological signs usually associated with ADHD, although there was an overlap in attentional problems between the groups. This may indicate that treatments developed for ADHD work differently in some adolescents with ASD + ADHD and adolescents with ADHD only.

  3. X-ray spectra of plasma radiation from laser induced low-power vacuum discharge

    Science.gov (United States)

    Romanov, I. V.; Kologrivov, A. A.; Paperny, V. L.; Rupasov, A. A.; Starodub, A. N.

    2018-02-01

    The x-ray spectra of plasma radiation in the wavelength range 30–300 Å are studied. The radiation is emitted from plasma of a vacuum discharge with storage energy less than 30 J that is initiated on an Al or Fe cathode by beam from neodymium laser with a power density up to 1012 W cm‑2. It is shown that both the spectral composition and intensity of radiation of hot micropinch plasma that is formed in the cathodic jet are determined by the set of the discharge and the laser pulse characteristics. By optimizing these characteristics, a mode of the discharge operation is attainable, in which a significant portion of the radiation energy is located in the long-wave band of the quasi-continuum (230–270 Å and 160–200 Å for Al and Fe cathodes, respectively). That makes it possible to treat such a discharge as an intense source of narrow-band soft x-ray radiation.

  4. Twelve million resolving power on 4.7 T Fourier transform ion cyclotron resonance instrument with dynamically harmonized cell--observation of fine structure in peptide mass spectra.

    Science.gov (United States)

    Popov, Igor A; Nagornov, Konstantin; Vladimirov, Gleb N; Kostyukevich, Yury I; Nikolaev, Eugene N

    2014-05-01

    Resolving power of about 12,000 000 at m/z 675 has been achieved on low field homogeneity 4.7 T magnet using a dynamically harmonized Fourier transform ion cyclotron resonance (FT ICR) cell. Mass spectra of the fine structure of the isotopic distribution of a peptide were obtained and strong discrimination of small intensity peaks was observed in case of resonance excitation of the ions of the whole isotopic cluster to the same cyclotron radius. The absence of some peaks from the mass spectra of the fine structure was explained basing on results of computer simulations showing strong ion cloud interactions, which cause the coalescence of peaks with m/z close to that of the highest magnitude peak. The way to prevent peak discrimination is to excite ion clouds of different m/z to different cyclotron radii, which was demonstrated and investigated both experimentally and by computer simulations.

  5. Sleep architecture and EEG power spectra in recently detoxified alcohol dependent patients.

    Science.gov (United States)

    Singh, Lokesh Kumar; Nizamie, S Haque; Tikka, Sai Krishna

    2018-02-01

    Persistent sleep abnormalities during abstinence are a harbinger for relapse in patients with chronic alcohol dependence. The present study aimed to compare polysomnography (PSG) data between 'recently detoxified' patients with chronic alcohol dependence and healthy controls. Both conventional sleep architectural and power spectral analyses were conducted. Twenty subjects in each of the groups were enrolled. A 2 nights' sleep (first-habituation and second-experimental) PSG data was collected. Computer assisted scoring supplemented by manual method using the Rechtschaffen and Kales criteria were used for sleep staging. Twenty eight channels were used for the EEG recording. Spectral power across early NREM (Non-rapid-eye-movement), Slow Wave Sleep and REM was computed using the Welch's averaged periodogram method. Results on conventional sleep staging showed that patients had significantly lesser total sleep time, sleep efficiency and stage shifts and longer sleep onset latency; while duration of each NREM stages were significantly lower, and latency of stage 2 NREM was significantly longer in patients. After controlling for multiple comparisons, spectral power analysis revealed significant differences only during REM sleep and specifically in high frequency (beta and gamma) bands. Stating the mutually complementary role of conventional and spectral analyses of polysomnography EEG data, we conclude that sleep abnormalities are fairly evident in recently detoxified alcohol dependent patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Sensitivity of Cosmic-Ray Proton Spectra to the Low-wavenumber Behavior of the 2D Turbulence Power Spectrum

    Science.gov (United States)

    Engelbrecht, N. E.; Burger, R. A.

    2015-12-01

    In this study, a novel ab initio cosmic ray (CR) modulation code that solves a set of stochastic transport equations equivalent to the Parker transport equation, and that uses output from a turbulence transport code as input for the diffusion tensor, is introduced. This code is benchmarked with a previous approach to ab initio modulation. The sensitivity of computed galactic CR proton spectra at Earth to assumptions made as to the low-wavenumber behavior of the two-dimensional (2D) turbulence power spectrum is investigated using perpendicular mean free path expressions derived from two different scattering theories. Constraints on the low-wavenumber behavior of the 2D power spectrum are inferred from the qualitative comparison of computed CR spectra with spacecraft observations at Earth. Another key difference from previous studies is that observed and inferred CR intensity spectra at 73 AU are used as boundary spectra instead of the usual local interstellar spectrum. Furthermore, the results presented here provide a tentative explanation as to the reason behind the unusually high galactic proton intensity spectra observed in 2009 during the recent unusual solar minimum.

  7. SENSITIVITY OF COSMIC-RAY PROTON SPECTRA TO THE LOW-WAVENUMBER BEHAVIOR OF THE 2D TURBULENCE POWER SPECTRUM

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N. E. [South African National Space Agency, Hermanus 7200 (South Africa); Burger, R. A., E-mail: n.eugene.engelbrecht@gmail.com [Center for Space Research, North-West University, Potchefstroom, 2520 (South Africa)

    2015-12-01

    In this study, a novel ab initio cosmic ray (CR) modulation code that solves a set of stochastic transport equations equivalent to the Parker transport equation, and that uses output from a turbulence transport code as input for the diffusion tensor, is introduced. This code is benchmarked with a previous approach to ab initio modulation. The sensitivity of computed galactic CR proton spectra at Earth to assumptions made as to the low-wavenumber behavior of the two-dimensional (2D) turbulence power spectrum is investigated using perpendicular mean free path expressions derived from two different scattering theories. Constraints on the low-wavenumber behavior of the 2D power spectrum are inferred from the qualitative comparison of computed CR spectra with spacecraft observations at Earth. Another key difference from previous studies is that observed and inferred CR intensity spectra at 73 AU are used as boundary spectra instead of the usual local interstellar spectrum. Furthermore, the results presented here provide a tentative explanation as to the reason behind the unusually high galactic proton intensity spectra observed in 2009 during the recent unusual solar minimum.

  8. Brain metabolic pattern analysis using a magnetic resonance spectra classification software in experimental stroke.

    Science.gov (United States)

    Jiménez-Xarrié, Elena; Davila, Myriam; Candiota, Ana Paula; Delgado-Mederos, Raquel; Ortega-Martorell, Sandra; Julià-Sapé, Margarida; Arús, Carles; Martí-Fàbregas, Joan

    2017-01-13

    Magnetic resonance spectroscopy (MRS) provides non-invasive information about the metabolic pattern of the brain parenchyma in vivo. The SpectraClassifier software performs MRS pattern-recognition by determining the spectral features (metabolites) which can be used objectively to classify spectra. Our aim was to develop an Infarct Evolution Classifier and a Brain Regions Classifier in a rat model of focal ischemic stroke using SpectraClassifier. A total of 164 single-voxel proton spectra obtained with a 7 Tesla magnet at an echo time of 12 ms from non-infarcted parenchyma, subventricular zones and infarcted parenchyma were analyzed with SpectraClassifier ( http://gabrmn.uab.es/?q=sc ). The spectra corresponded to Sprague-Dawley rats (healthy rats, n = 7) and stroke rats at day 1 post-stroke (acute phase, n = 6 rats) and at days 7 ± 1 post-stroke (subacute phase, n = 14). In the Infarct Evolution Classifier, spectral features contributed by lactate + mobile lipids (1.33 ppm), total creatine (3.05 ppm) and mobile lipids (0.85 ppm) distinguished among non-infarcted parenchyma (100% sensitivity and 100% specificity), acute phase of infarct (100% sensitivity and 95% specificity) and subacute phase of infarct (78% sensitivity and 100% specificity). In the Brain Regions Classifier, spectral features contributed by myoinositol (3.62 ppm) and total creatine (3.04/3.05 ppm) distinguished among infarcted parenchyma (100% sensitivity and 98% specificity), non-infarcted parenchyma (84% sensitivity and 84% specificity) and subventricular zones (76% sensitivity and 93% specificity). SpectraClassifier identified candidate biomarkers for infarct evolution (mobile lipids accumulation) and different brain regions (myoinositol content).

  9. Theoretical research and experimental validation of elastic dynamic load spectra on bogie frame of high-speed train

    Science.gov (United States)

    Zhu, Ning; Sun, Shouguang; Li, Qiang; Zou, Hua

    2016-05-01

    When a train runs at high speeds, the external exciting frequencies approach the natural frequencies of bogie critical components, thereby inducing strong elastic vibrations. The present international reliability test evaluation standard and design criteria of bogie frames are all based on the quasi-static deformation hypothesis. Structural fatigue damage generated by structural elastic vibrations has not yet been included. In this paper, theoretical research and experimental validation are done on elastic dynamic load spectra on bogie frame of high-speed train. The construction of the load series that correspond to elastic dynamic deformation modes is studied. The simplified form of the load series is obtained. A theory of simplified dynamic load-time histories is then deduced. Measured data from the Beijing-Shanghai Dedicated Passenger Line are introduced to derive the simplified dynamic load-time histories. The simplified dynamic discrete load spectra of bogie frame are established. Based on the damage consistency criterion and a genetic algorithm, damage consistency calibration of the simplified dynamic load spectra is finally performed. The computed result proves that the simplified load series is reasonable. The calibrated damage that corresponds to the elastic dynamic discrete load spectra can cover the actual damage at the operating conditions. The calibrated damage satisfies the safety requirement of damage consistency criterion for bogie frame. This research is helpful for investigating the standardized load spectra of bogie frame of high-speed train.

  10. Measuring x-ray spectra of flash radiographic sources [PowerPoint

    Energy Technology Data Exchange (ETDEWEB)

    Gehring, Amanda Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Espy, Michelle A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haines, Todd Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mendez, Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moir, David C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sedillo, Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shurter, Roger P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Volegov, Petr Lvovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Webb, Timothy J [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-02

    The x-ray spectra of flash radiographic sources are difficult to measure. The sources measured were Radiographic Integrated Test Stand-6 (370 rad at 1 m; 50 ns pulse) and Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) (550 rad at 1 m; 50 ns pulse). Features of the Compton spectrometer are described, and spectra are shown. Additional slides present data on instrumental calibration.

  11. Plasma heating systems planned for the Argonne experimental power reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bertoncini, P.; Brooks, J.; Fasolo, J.; Mills, F.; Moretti, A.; Norem, J.

    1976-01-01

    A scoping study and conceptual design of a tokamak experimental power reactor (TEPR) have been completed. The design objectives of the TEPR are to operate for ten years at or near electrical power breakeven conditions with a duty factor of greater than or equal to 50 percent and to demonstrate the feasibility of tokamak fusion power reactor techniques. These objectives can be met by a design which has a major radius of 6.25 m and a plasma radius of 2.1 m. Parameters for this reactor are listed, and a diagram is given. This paper will describe TEPR plasma heating systems. Neutral beam heating and rf heating are described.

  12. Experimental study of emission Z-pinch spectra in the axial and radial directions at the Angara-5-1 facility

    Directory of Open Access Journals (Sweden)

    Alexandrov V.V.

    2017-01-01

    Full Text Available Data on the energy, power and spectra composition of the soft x-ray pulse of powerful Z-pinch plasmas in the axial and radial directions in the photon energy range of 0.02 - 2 keV are presented. The data are obtained from the analysis of experimental results on the implosion of cylindrical arrays with a diameter of 1.2 cm and a height of 1.6 cm of tungsten wires diameter of 6 μm, the linear mass of 220 μg/cm at a current in the range of 2.2 – 3.5 MA at the Angara-5-1 facility.

  13. Intrinsic dendritic filtering gives low-pass power spectra of local field potentials

    DEFF Research Database (Denmark)

    Lindén, Henrik; Pettersen, Klas H; Einevoll, Gaute T

    2010-01-01

    The local field potential (LFP) is among the most important experimental measures when probing neural population activity, but a proper understanding of the link between the underlying neural activity and the LFP signal is still missing. Here we investigate this link by mathematical modeling...... of contributions to the LFP from a single layer-5 pyramidal neuron and a single layer-4 stellate neuron receiving synaptic input. An intrinsic dendritic low-pass filtering effect of the LFP signal, previously demonstrated for extracellular signatures of action potentials, is seen to strongly affect the LFP power...... of the observed LFP. Two approximate schemes for calculating the LFP, the dipole approximation and the two-monopole approximation, are tested and found to be potentially useful for translating results from large-scale neural network models into predictions for results from electroencephalographic (EEG...

  14. THE RELATION BETWEEN GAS DENSITY AND VELOCITY POWER SPECTRA IN GALAXY CLUSTERS: QUALITATIVE TREATMENT AND COSMOLOGICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Zhuravleva, I.; Allen, S. W. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305 (United States); Churazov, E. M.; Gaspari, M. [Max Planck Institute for Astrophysics, Karl-Schwarzschild-Strasse 1, D-85741 Garching (Germany); Schekochihin, A. A. [The Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom); Lau, E. T.; Nagai, D. [Department of Physics, Yale University, New Haven, CT 06520 (United States); Nelson, K. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Parrish, I. J., E-mail: zhur@stanford.edu [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

    2014-06-10

    We address the problem of evaluating the power spectrum of the velocity field of the intracluster medium using only information on the plasma density fluctuations, which can be measured today by Chandra and XMM-Newton observatories. We argue that for relaxed clusters there is a linear relation between the rms density and velocity fluctuations across a range of scales, from the largest ones, where motions are dominated by buoyancy, down to small, turbulent scales: (δρ{sub k}/ρ){sup 2}=η{sub 1}{sup 2}(V{sub 1,k}/c{sub s}){sup 2}, where δρ {sub k}/ρ is the spectral amplitude of the density perturbations at wavenumber k, V{sub 1,k}{sup 2}=V{sub k}{sup 2}/3 is the mean square component of the velocity field, c{sub s} is the sound speed, and η{sub 1} is a dimensionless constant of the order of unity. Using cosmological simulations of relaxed galaxy clusters, we calibrate this relation and find η{sub 1} ≈ 1 ± 0.3. We argue that this value is set at large scales by buoyancy physics, while at small scales the density and velocity power spectra are proportional because the former are a passive scalar advected by the latter. This opens an interesting possibility to use gas density power spectra as a proxy for the velocity power spectra in relaxed clusters across a wide range of scales.

  15. Experimental Studies of Laser-Induced Fluorescence Spectra of Plants Immunity to the Kind of Ground

    Directory of Open Access Journals (Sweden)

    Yu. V. Fedotov

    2015-01-01

    Full Text Available Various external factors (pollutants available in the soil, a lack or insufficient amount of water and nutrients, etc. lead to stressful conditions of plants and impossibility of their normal development. At the early stages it is difficult to identify visually the stressful situations of plants. Therefore development of methods and devices to detect stressful states is important.A method of the laser-induced fluorescence is one of perspective methods for detection of stressful conditions of plants.In spite of quite a great number of work presenting results of the pilot studies of fluorescence spectra of vegetation, there are some important issues, which are unclear.The paper gives results of pilot studies of stability of a spectrum form of the laser-induced fluorescence of plants for different types of soil at the wavelength of excitation fluorescence of 532 nm.Results of processing fluorescence spectra of plants show:- fluorescence spectra of plants grown up under similar conditions have good repeatability of a spectra form for different samples of plants and different measurement time for each type of studied soil. The ratio value R of the fluorescence intensity at the wavelength of 685 nm to the fluorescence intensity at the wavelength of 740 nm has high stability. The standard deviation in sampling of the ratio R of different samples of a plant for one type of soil (for width of spectral ranges of recording fluorescent radiation of 10 nm lies in the range ~ 0.055 - ~ 0.12;- a difference in plant fluorescence spectra between themselves for different types of soil has the same order as a difference in fluorescence spectra of different samples of a plant for one type of soil. Difference in average value of the ratio R for different types of soil lies in the range ~ 0.01 - ~ 0.15.Thus, the value of the ratio R is steady against a type of soil and can be used to control a condition of plants.

  16. Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults

    OpenAIRE

    Choi, Jong-Bae; Lee, Yu-Jin G.; Jeong, Do-Un

    2017-01-01

    Objective The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. Methods We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. Results The ni...

  17. Anomalous diffraction approximation to the light scattering coefficient spectra of marine particles with power-law size distribution.

    Science.gov (United States)

    Matciak, Maciej

    2012-12-03

    Based on anomalous diffraction approximation, analytical expressions for the scattering coefficient of marine particles with power-law size distribution in the infinite domain of sizes (0, ∞) were derived. Comparison with the exact Mie solution for the light scattering by spheres indicated that the obtained expressions can describe the relative spectral variability of the scattering coefficient well. This is demonstrated and discussed for the scattering spectra of main types of marine particulates characterized by different optical properties.

  18. Infrared Spectra of Human Breast Tumor Tissue and Experimental Animal Tumors

    Science.gov (United States)

    Tolstorozhev, G. B.; Belkov, M. V.; Skornyakov, I. V.; Pekhnyo, V. I.; Kozachkova, A. N.; Tsarik, H. V.; Kutsenko, I. P.; Sharykina, N. I.; Butra, V. A.

    2015-01-01

    We have used Fourier transform IR spectroscopy methods to conduct comparative studies of human breast tumors and sarcoma 180 tumor grafted into mice. The IR spectral parameters used to identify tumor tissue in mice with the sarcoma 180 strain proved to be identical to the parameters for human breast tissue in cancer. In the presence of a malignant tumor in humans, the most intense C=O vibrational bands in the protein molecules are observed in the interval 1710-1680 cm-1. For a benign tumor, in the IR spectra of breast tissue the intense bands are located in the interval 1670-1650 cm-1. We spectroscopically monitored the diagnosis and the chemotherapy process using the model of sarcoma 180 in mice. As the therapeutic drugs, we used synthesized coordination compounds based on palladium complexes with diphosphonic acid derivatives. We demonstrate the promising potential of palladium complexes with zoledronic acid as an effective cytostatic. In therapy using a palladium complex with zoledronic acid, the effect of tumor growth inhibition is accompanied by a change in its spectral characteristics. The parameters of the IR spectra for tumor tissue after treatment are close to those of the IR spectra for healthy tissue.

  19. FT-Raman and FTIR spectra of photoactive aminobenzazole derivatives in the solid state: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Rodrigo Martins [Universidade Federal do Pampa, Campus Bagé, Grupo de Pesquisa em Espectroscopia de Materiais Fotônicos, 96400-970 Bagé, RS (Brazil); Rodembusch, Fabiano Severo [Universidade Federal do Rio Grande do Sul, Grupo de Pesquisa em Fotoquímica Orgânica Aplicada, Av. Bento Gonçalves 9500, CEP 91501-970 Porto Alegre, RS (Brazil); Habis, Charles [Northern Virginia Community College, Manassas, VA (United States); Moreira, Eduardo Ceretta, E-mail: eduardomoreira@unipampa.edu.br [Universidade Federal do Pampa, Campus Bagé, Grupo de Pesquisa em Espectroscopia de Materiais Fotônicos, 96400-970 Bagé, RS (Brazil)

    2014-12-15

    This study reports the experimental investigation of two photoactive aminobenzazole derivatives in the solid state by FT-Raman and Infrared Spectroscopies (FTIR) and its comparison with theoretical models. The optimized molecular structure, vibrational frequencies, and corresponding vibrational assignments of these compounds have been investigated experimentally and theoretically using Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) and Gaussian03 Software Package. The FT-Raman and FTIR spectra were acquired with high resolution and emission frequencies identified by simulating the vibrational modes. The most intense peak observed in the FT-Raman spectra is the in-plane deformation vibrational of O–H bond that could be related to the vibrational region responsible for the stabilization of the enol conformer in the ground state which undergoes ESIPT to form a keto tautomer in the excited state. Additionally, the position of the amino group played an important role on the vibrational characteristics of the studied compounds. Also, the simulations proved to be a good approach in undertaking the FTIR and FT-Raman experiments. The use of graphic correlations helps us to determine the method and basis that best fit the experimental results. - Highlights: • Structural and vibrational properties of two aminobenzazoles were reported. • Comparison between experimental techniques and theoretical models. • The position of the amino group played an important role on the vibrational characteristics of the studied compounds.

  20. Slow EEG-power spectra correlate with haemodynamic changes during laryngoscopy and intubation following induction with fentanyl or sufentanil.

    Science.gov (United States)

    Freye, E; Dehnen-Seipel, H; Latasch, L; Behler, M; Wilder-Smith, O H

    1999-01-01

    We studied nociception-associated arousal following laryngoscopy and intubation in patients scheduled for elective open heart surgery, using EEG power spectra and hemodynamics. Either fentanyl (7 micrograms/kg; n = 30) or sufentanil (1 microgram/kg; n = 30) were given in a randomized fashion to induce anesthesia in heavily premedicated patients, followed by pancuronium bromide (100 micrograms/kg). EEG-power spectra (delta, theta, alpha, beta) as well as mean arterial blood pressure (MAP) and heart rate (HF) were measured at the following end-points: before the induction of anesthesia (control), 1 and 10 minutes after laryngoscopy and intubation (L & I). Linear regression analysis was computed to determine which of the EEG power spectra was most sensitive to detect insufficient blockade of nociceptive-related arousal when correlated with haemodynamics. In the fentanyl group the change in HF closely correlated with the decrease of power in the slow delta- and theta-domain (r2 = 0.98 and r2 = 0.89 respectively) of the EEG. The change in MAP also closely correlated with a decrease in the slow delta- and theta-domain (r2 = 0.97 and r2 = 0.99 respectively). There was little correlation in regard to spectral edge frequency (SEF) and HF and MAP changes (r2 = 0.36 and r2 = 0.12 respectively). In the sufentanil group the change in HF correlated closely with an increase of power in the fast alpha and a decrease in the slow theta-domain (r2 = 0.91 and r2 = 0.98 respectively) of the EEG. The changes in MAP closely correlated with an increase in the fast alpha-band a decrease in the slow theta-domain (r2 = 0.98 and r2 = 0.73 respectively). Also there was little correlation of SEF with HF and MAP changes (r2 = 0.09 and r2 = 0.02 respectively). Among the EEG-spectra, reduction of power in the slow delta- and theta-bands are the most sensitive parameters to determine insufficient antinociception of opioids commonly used for the induction in cardiac anesthesia. Increase of power in

  1. Topology Zero: Advancing Theory and Experimentation for Power Electronics Education

    Science.gov (United States)

    Luchino, Federico

    For decades, power electronics education has been based on the fundamentals of three basic topologies: buck, boost, and buck-boost. This thesis presents the analytical framework for the Topology Zero, a general circuit topology that integrates the basic topologies and provides significant insight into the behaviour of converters. As demonstrated, many topologies are just particular cases of the Topology Zero, an important contribution towards the understanding, integration, and conceptualization of topologies. The investigation includes steady-state, small-signal, and frequency response analysis. The Topology Zero is physically implemented as an educational system. Experimental results are presented to show control applications and power losses analysis using the educational system. The steady-state and dynamic analyses of the Topology Zero provide profuse proof of its suitability as an integrative topology, and of its ability to be indirectly controlled. As well, the implementation of the Topology Zero within an experimentation system is explained and application examples are provided.

  2. An experimental and theoretical study of the valence shell photoelectron spectra of 2-chloropyridine and 3-chloropyridine

    Science.gov (United States)

    Holland, D. M. P.; Powis, I.; Trofimov, A. B.; Menzies, R. C.; Potts, A. W.; Karlsson, L.; Badsyuk, I. L.; Moskovskaya, T. E.; Gromov, E. V.; Schirmer, J.

    2017-10-01

    The valence shell photoelectron spectra of 2-chloropyridine and 3-chloropyridine have been studied both experimentally and theoretically. Synchrotron radiation has been employed to record angle resolved photoelectron spectra in the photon energy range 20-100 eV, and these have enabled anisotropy parameters and branching ratios to be derived. The experimental results have been compared with theoretical predictions obtained using the continuum multiple scattering Xα approach. This comparison shows that the anisotropy parameter associated with the nominally chlorine lone-pair orbital lying in the molecular plane is strongly affected by the atomic Cooper minimum. In contrast, the photoionization dynamics of the second lone-pair orbital, orientated perpendicular to the molecular plane, seem relatively unaffected by this atomic phenomenon. The outer valence ionization has been studied theoretically using the third-order algebraic-diagrammatic construction (ADC(3)) approximation scheme for the one-particle Green's function, the outer valence Green's function method, and the equation-of-motion (EOM) coupled cluster (CC) theory at the level of the EOM-IP-CCSD and EOM-EE-CC3 models. The convergence of the results to the complete basis set limit has been investigated. The ADC(3) method has been employed to compute the complete valence shell ionization spectra of 2-chloropyridine and 3-chloropyridine. The relaxation mechanism for ionization of the nitrogen σ-type lone-pair orbital (σN LP) has been found to be different to that for the corresponding chlorine lone-pair (σCl LP). For the σN LP orbital, π-π* excitations play the main role in the screening of the lone-pair hole. In contrast, excitations localized at the chlorine site involving the chlorine πCl LP lone-pair and the Cl 4p Rydberg orbital are the most important for the σCl LP orbital. The calculated photoelectron spectra have allowed assignments to be proposed for most of the structure observed in the

  3. Intellectual Disabilities and Power Spectra Analysis during Sleep: A New Perspective on Borderline Intellectual Functioning

    Science.gov (United States)

    Esposito, M.; Carotenuto, M.

    2014-01-01

    Background: The role of sleep in cognitive processes has been confirmed by a growing number of reports for all ages of life. Analysing sleep electroencephalogram (EEG) spectra may be useful to study cortical organisation in individuals with Borderline Intellectual Functioning (BIF), as seen in other disturbances even if it is not considered a…

  4. Experimental study of lithium target under high power load

    Energy Technology Data Exchange (ETDEWEB)

    Khripunov, B.I. E-mail: boris@nfi.kiae.ru; Petrov, V.B.; Shapkin, V.V.; Pleshakov, A.S.; Rupyshev, A.S.; Antonov, N.V.; Litnovsky, A.M.; Romanov, P.V.; Shpansky, Yu.S.; Evtikhin, V.A.; Lyublinsky, I.E.; Vertkov, A.V

    2001-03-01

    This paper presents experimental research on simulation of a free liquid lithium surface under high heat flux impact for divertor application. Capillary porous structure (CPS) was taken to form the free liquid metal surface imitating divertor target plate. Experiments were performed in the SPRUT-4 linear plasma device with electron beam as power source. Lithium-filled targets were investigated at 1-50 MW/m{sup 2} heat loads in steady state. Lithium evaporation, energy and mass balance, surface temperature, vapor ionization, lithium plasma parameters and radiation were studied. Detailed thermal analysis was made to study heat flows in the target and their correspondence with experimental observations. Durable operation of the setup was possible in the range 1-20 MW/m{sup 2} without damage of the structure. The relevance of the experimental performance to divertor condition is analyzed.

  5. Experimental astrophysics with high power lasers and Z pinches

    Energy Technology Data Exchange (ETDEWEB)

    Remington, B A; Drake, R P; Ryutov, D D

    2004-12-10

    With the advent of high energy density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, mm-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors; equations of state relevant to planetary interiors; strong shock driven nonlinear hydrodynamics and radiative dynamics, relevant to supernova explosions and subsequent evolution; protostellar jets and high Mach-number flows; radiatively driven molecular clouds and nonlinear photoevaporation front dynamics; and photoionized plasmas relevant to accretion disks around compact objects, such as black holes and neutron stars.

  6. Power Spectrum Computation for an Arbitrary Phase Noise Using Middleton's Convolution Series: Implementation Guideline and Experimental Illustration.

    Science.gov (United States)

    Brochard, Pierre; Sudmeyer, Thomas; Schilt, Stephane

    2017-11-01

    In this paper, we revisit the convolution series initially introduced by Middleton several decades ago to determine the power spectrum (or spectral line shape) of a periodic signal from its phase noise power spectral density. This topic is of wide interest, as it has an important impact on many scientific areas that involve lasers and oscillators. We introduce a simple guideline that enables a fairly straightforward computation of the power spectrum corresponding to an arbitrary phase noise. We show the benefit of this approach on a computational point of view, and apply it to various types of experimental signals with different phase noise levels, showing a very good agreement with the experimental spectra. This approach also provides a qualitative and intuitive understanding of the power spectrum corresponding to different regimes of phase noise.

  7. Image simulation and a model of noise power spectra across a range of mammographic beam qualities.

    Science.gov (United States)

    Mackenzie, Alistair; Dance, David R; Diaz, Oliver; Young, Kenneth C

    2014-12-01

    The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise in CR. The use of the

  8. Image simulation and a model of noise power spectra across a range of mammographic beam qualities

    Energy Technology Data Exchange (ETDEWEB)

    Mackenzie, Alistair, E-mail: alistairmackenzie@nhs.net; Dance, David R.; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Diaz, Oliver [Centre for Vision, Speech and Signal Processing, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom and Computer Vision and Robotics Research Institute, University of Girona, Girona 17071 (Spain)

    2014-12-15

    Purpose: The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Methods: Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. Results: The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise

  9. The PowerAtlas: a power and sample size atlas for microarray experimental design and research

    Directory of Open Access Journals (Sweden)

    Wang Jelai

    2006-02-01

    Full Text Available Abstract Background Microarrays permit biologists to simultaneously measure the mRNA abundance of thousands of genes. An important issue facing investigators planning microarray experiments is how to estimate the sample size required for good statistical power. What is the projected sample size or number of replicate chips needed to address the multiple hypotheses with acceptable accuracy? Statistical methods exist for calculating power based upon a single hypothesis, using estimates of the variability in data from pilot studies. There is, however, a need for methods to estimate power and/or required sample sizes in situations where multiple hypotheses are being tested, such as in microarray experiments. In addition, investigators frequently do not have pilot data to estimate the sample sizes required for microarray studies. Results To address this challenge, we have developed a Microrarray PowerAtlas 1. The atlas enables estimation of statistical power by allowing investigators to appropriately plan studies by building upon previous studies that have similar experimental characteristics. Currently, there are sample sizes and power estimates based on 632 experiments from Gene Expression Omnibus (GEO. The PowerAtlas also permits investigators to upload their own pilot data and derive power and sample size estimates from these data. This resource will be updated regularly with new datasets from GEO and other databases such as The Nottingham Arabidopsis Stock Center (NASC. Conclusion This resource provides a valuable tool for investigators who are planning efficient microarray studies and estimating required sample sizes.

  10. Power Spectra and Eddy Dissipation Rate Measured by the Coyote Unmanned Aircraft System in Hurricane Edouard (2014)

    Science.gov (United States)

    Kalina, E.; Cione, J.; Bryan, G. H.; Lenschow, D. H.; Fairall, C. W.

    2016-12-01

    Open-ocean measurements of turbulence variables in the tropical cyclone (TC) boundary layer are rare, given the dangers posed by convective downdrafts, high waves, and sea spray to manned hurricane reconnaissance aircraft. The Coyote Unmanned Aircraft System (UAS) represents an opportunity to mitigate the risk to personnel while simultaneously collecting low-altitude measurements of air pressure, temperature, humidity, and wind in TCs. In 2014, the Coyote UAS flew at a height of h = 760 m in Hurricane Edouard for 45 min. The resulting wind velocity measurements were used to estimate the turbulent eddy dissipation rate (ɛ) along the Coyote flight track, using power spectra and the second-order velocity structure function. Power spectra of both the longitudinal (Suu) and transverse wind components (Svv) exhibited well-defined inertial subranges with five-thirds scaling, as expected from Kolmogorov (1941). The ratio Svv:Suu was 4:3, in agreement with theory. Under the moderate wind speeds (15-25 m s-1) sampled by the Coyote, estimates of ɛ from the power spectra and structure function ranged from 2-3.5×10-4 m2 s-3. An idealized TC simulation with Cloud Model version 1 (CM1) and a horizontal grid spacing of dx = 20 m was then used to support the observed estimates of ɛ. Along the mock Coyote flight path, the model domain-averaged value of ɛ was 3.0×10-4 m2 s-3, which is within the range of the observationally-based estimates. This agreement was achieved despite the relatively slow sampling rate (1 Hz) of the Coyote sensors and occasional missing data. Therefore, a 1-Hz sampling rate may be adequate for estimating ɛ, and time series with missing samples may still contain the necessary information to estimate the power spectra and structure functions, and thus ɛ. These findings are motivating subsequent Coyote flights into high-wind regions of TCs to collect turbulence measurements that will be used to evaluate subgrid turbulence schemes for numerical models

  11. Linked Scatter Plots, A Powerful Exploration Tool For Very Large Sets of Spectra

    Science.gov (United States)

    Carbon, Duane Francis; Henze, Christopher

    2015-08-01

    We present a new tool, based on linked scatter plots, that is designed to efficiently explore very large spectrum data sets such as the SDSS, APOGEE, LAMOST, GAIA, and RAVE data sets.The tool works in two stages: the first uses batch processing and the second runs interactively. In the batch stage, spectra are processed through our data pipeline which computes the depths relative to the local continuum at preselected feature wavelengths. These depths, and any additional available variables such as local S/N level, magnitudes, colors, positions, and radial velocities, are the basic measured quantities used in the interactive stage.The interactive stage employs the NASA hyperwall, a configuration of 128 workstation displays (8x16 array) controlled by a parallelized software suite running on NASA's Pleiades supercomputer. Each hyperwall panel is used to display a fully linked 2-D scatter plot showing the depth of feature A vs the depth of feature B for all of the spectra. A and B change from panel to panel. The relationships between the various (A,B) strengths and any distinctive clustering, as well as unique outlier groupings, are visually apparent when examining and inter-comparing the different panels on the hyperwall. In addition, the data links between the scatter plots allow the user to apply a logical algebra to the measurements. By graphically selecting the objects in any interesting region of any 2-D plot on the hyperwall, the tool immediately and clearly shows how the selected objects are distributed in all the other 2-D plots. The selection process may be repeated multiple times and, at each step, the selections can represent a sequence of logical constraints on the measurements, revealing those objects which satisfy all the constraints thus far. The spectra of the selected objects may be examined at any time on a connected workstation display.Using over 945,000,000 depth measurements from 569,738 SDSS DR10 stellar spectra, we illustrate how to quickly

  12. A randomized controlled trial into the effects of neurofeedback, methylphenidate, and physical activity on EEG power spectra in children with ADHD

    NARCIS (Netherlands)

    Janssen, T.W.P.; Bink, M.; Gelade, K.; van Mourik, R.; Maras, A.; Oosterlaan, J.

    2016-01-01

    Background The clinical and neurophysiological effects of neurofeedback (NF) as treatment for children with ADHD are still unclear. This randomized controlled trial (RCT) examined electroencephalogram (EEG) power spectra before and after NF compared to methylphenidate (MPH) treatment and physical

  13. Delta and theta power spectra of night sleep EEG are higher in breast-feeding mothers than in non-pregnant women.

    Science.gov (United States)

    Nishihara, Kyoko; Horiuchi, Shigeko; Eto, Hiromi; Uchida, Sunao; Honda, Makoto

    2004-09-23

    The power spectra of night sleep EEGs of 12 breast-feeding 9-13 week postpartum mothers were analyzed and compared with those of 12 non-pregnant women. The power spectra in the delta and theta frequency range during NREM sleep for breast-feeding mothers were significantly higher than those for non-pregnant women. In addition, the all-night sleep patterns of the mothers were classified into two groups - interrupted sleep due to taking care of their infants and non-interrupted sleep - in order to observe the influence of partial sleep deprivation. The power spectra in the delta and theta frequency range were not significantly different between them. This result suggests that increased delta and theta power spectra during postpartum sleep do not result from partial sleep deprivation. The role of prolactin in breast-feeding mothers' sleep is also discussed.

  14. On the origin of power-law X-ray spectra of active galactic nuclei

    Science.gov (United States)

    Schlosman, I.; Shaham, J.; Shaviv, G.

    1984-01-01

    In the present analytical model for a power law X-ray continuum production in active galactic nuclei, the dissipation of turbulent energy flux above the accretion disk forms an optically thin transition layer with an inverted temperature gradient. The emitted thermal radiation has a power law spectrum in the 0.1-100 keV range, with a photon energy spectral index gamma of about 0.4-1.0. Thermal X-ray contribution from the layer is 5-10 percent of the total disk luminosity. The gamma value of 0.75 is suggested as a 'natural' power law index for Seyfert galaxies and QSOs.

  15. The Effect of a Finite Measurement Volume on Power Spectra from a Burst Type LDA

    DEFF Research Database (Denmark)

    Buchhave, Preben; Velte, Clara Marika; K. George, William

    2014-01-01

    time.We compare analytical expressions for the bias and distortion of the velocity power spectrum computed from computer-generated data. We then compare the spectrum from the computer-generated data and a power spectrum from a measurement on a free turbulent jet in air and conclude that we have a valid......We analyze the effects of a finite size measurement volume on the power spectrum computed fromdata acquired with a burst-type laser Doppler anemometer. The finite measurement volume causes temporal distortions in acquisition of the data resulting in phenomena such as finite processing time and dead...... understanding of the effects of the finite measurement volume on the measured velocity power spectrum....

  16. 1/f 2 Characteristics and isotropy in the fourier power spectra of visual art, cartoons, comics, mangas, and different categories of photographs.

    Directory of Open Access Journals (Sweden)

    Michael Koch

    Full Text Available Art images and natural scenes have in common that their radially averaged (1D Fourier spectral power falls according to a power-law with increasing spatial frequency (1/f(2 characteristics, which implies that the power spectra have scale-invariant properties. In the present study, we show that other categories of man-made images, cartoons and graphic novels (comics and mangas, have similar properties. Further on, we extend our investigations to 2D power spectra. In order to determine whether the Fourier power spectra of man-made images differed from those of other categories of images (photographs of natural scenes, objects, faces and plants and scientific illustrations, we analyzed their 2D power spectra by principal component analysis. Results indicated that the first fifteen principal components allowed a partial separation of the different image categories. The differences between the image categories were studied in more detail by analyzing whether the mean power and the slope of the power gradients from low to high spatial frequencies varied across orientations in the power spectra. Mean power was generally higher in cardinal orientations both in real-world photographs and artworks, with no systematic difference between the two types of images. However, the slope of the power gradients showed a lower degree of mean variability across spectral orientations (i.e., more isotropy in art images, cartoons and graphic novels than in photographs of comparable subject matters. Taken together, these results indicate that art images, cartoons and graphic novels possess relatively uniform 1/f(2 characteristics across all orientations. In conclusion, the man-made stimuli studied, which were presumably produced to evoke pleasant and/or enjoyable visual perception in human observers, form a subset of all images and share statistical properties in their Fourier power spectra. Whether these properties are necessary or sufficient to induce aesthetic

  17. 1/f 2 Characteristics and isotropy in the fourier power spectra of visual art, cartoons, comics, mangas, and different categories of photographs.

    Science.gov (United States)

    Koch, Michael; Denzler, Joachim; Redies, Christoph

    2010-08-19

    Art images and natural scenes have in common that their radially averaged (1D) Fourier spectral power falls according to a power-law with increasing spatial frequency (1/f(2) characteristics), which implies that the power spectra have scale-invariant properties. In the present study, we show that other categories of man-made images, cartoons and graphic novels (comics and mangas), have similar properties. Further on, we extend our investigations to 2D power spectra. In order to determine whether the Fourier power spectra of man-made images differed from those of other categories of images (photographs of natural scenes, objects, faces and plants and scientific illustrations), we analyzed their 2D power spectra by principal component analysis. Results indicated that the first fifteen principal components allowed a partial separation of the different image categories. The differences between the image categories were studied in more detail by analyzing whether the mean power and the slope of the power gradients from low to high spatial frequencies varied across orientations in the power spectra. Mean power was generally higher in cardinal orientations both in real-world photographs and artworks, with no systematic difference between the two types of images. However, the slope of the power gradients showed a lower degree of mean variability across spectral orientations (i.e., more isotropy) in art images, cartoons and graphic novels than in photographs of comparable subject matters. Taken together, these results indicate that art images, cartoons and graphic novels possess relatively uniform 1/f(2) characteristics across all orientations. In conclusion, the man-made stimuli studied, which were presumably produced to evoke pleasant and/or enjoyable visual perception in human observers, form a subset of all images and share statistical properties in their Fourier power spectra. Whether these properties are necessary or sufficient to induce aesthetic perception remains

  18. Experimental investigation of thermoelectric power generation versus coolant pumping power in a microchannel heat sink

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse; Andreasen, Søren Juhl

    2012-01-01

    The coolant heat sinks in thermoelectric generators (TEG) play an important role in order to power generation in the energy systems. This paper explores the effective pumping power required for the TEGs cooling at five temperature difference of the hot and cold sides of the TEG. In addition......, the temperature distribution and the pressure drop in sample microchannels are considered at four sample coolant flow rates. The heat sink contains twenty plate-fin microchannels with hydraulic diameter equal to 0.93 mm. The experimental results show that there is a unique flow rate that gives maximum net...

  19. Experimental effective shape control of a powered transfemoral prosthesis.

    Science.gov (United States)

    Gregg, Robert D; Lenzi, Tommaso; Fey, Nicholas P; Hargrove, Levi J; Sensinger, Jonathon W

    2013-06-01

    This paper presents the design and experimental implementation of a novel feedback control strategy that regulates effective shape on a powered transfemoral prosthesis. The human effective shape is the effective geometry to which the biological leg conforms--through movement of ground reaction forces and leg joints--during the stance period of gait. Able-bodied humans regulate effective shapes to be invariant across conditions such as heel height, walking speed, and body weight, so this measure has proven to be a very useful tool for the alignment and design of passive prostheses. However, leg joints must be actively controlled to assume different effective shapes that are unique to tasks such as standing, walking, and stair climbing. Using our previous simulation studies as a starting point, we model and control the effective shape as a virtual kinematic constraint on the powered Vanderbilt prosthetic leg with a custom instrumented foot. An able-bodied subject used a by-pass adapter to walk on the controlled leg over ground and over a treadmill. These preliminary experiments demonstrate, for the first time, that effective shape (or virtual constraints in general) can be used to control a powered prosthetic leg.

  20. Finslerian dipolar modulation of the CMB power spectra at scales 2 < l < 600

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xin [Chongqing University, Department of Physics, Chongqing (China); Chinese Academy of Sciences, CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); Lin, Hai-Nan [Chongqing University, Department of Physics, Chongqing (China)

    2017-05-15

    A common explanation for the CMB power asymmetry is to introduce a dipolar modulation at the stage of inflation, where the primordial power spectrum is spatially varying. If the universe in the stage of inflation is Finslerian, and if the Finsler spacetime is non-reversible under parity flip, x → -x, then a three dimensional spectrum which is a function of wave vector and direction is valid. In this paper, a three dimensional primordial power spectrum with preferred direction is derived in the framework of Finsler spacetime. It is found that the amplitude of dipolar modulation is related to the Finslerian parameter, which in turn is a function of wave vector. The angular correlation coefficients are presented, and the numerical results for the anisotropic correlation coefficients over the multipole range 2 < l < 600 are given. (orig.)

  1. Experimental and theoretical study of the vibrational spectra of oligoureas: helical versus β-sheet-type secondary structures.

    Science.gov (United States)

    Cavagnat, Dominique; Claudon, Paul; Fischer, Lucile; Guichard, Gilles; Desbat, Bernard

    2011-04-21

    Ab initio calculations of two oligoureas stabilized in helix and sheet organization have been performed. The hydrogen bond distances were found to be almost the same for both structures. The vibrational assignment of the two oligourea structures and the direction of the transition moment of each vibration have been determined. From these results, and using the experimental isotropic optical index determined for one oligourea, we have established the anisotropic infrared optical files for the two structures. Interestingly, most urea absorptions vibrate in only one principal direction. Also, the shift of the carbonyl band is weaker and inverse to what was reported for corresponding protein secondary structures. Finally, simulations of the Polarization Modulation Infrared Reflection Absorption Spectroscopy (PMIRRAS) and Attenuated Reflection Spectroscopy (ATR) infrared spectra demonstrate the possibility to determine the orientation of the oligoureas in thin or ultrathin films, even if in some cases it may be difficult to unambiguously assign their secondary structure.

  2. The diagnostic value of power spectra analysis of the sleep electroencephalography in narcoleptic patients.

    Science.gov (United States)

    Christensen, Julie Anja Engelhard; Munk, Emil Gammelmark Schreiner; Peppard, Paul E; Young, Terry; Mignot, Emmanuel; Sorensen, Helge Bjarrup Dissing; Jennum, Poul

    2015-12-01

    Manifestations of narcolepsy with cataplexy (NC) include disturbed nocturnal sleep - hereunder sleep-wake instability, decreased latency to rapid eye movement (REM) sleep, and dissociated REM sleep events. In this study, we characterized the electroencephalography (EEG) of various sleep stages in NC versus controls. EEG power spectral density (PSD) was computed in 136 NC patients and 510 sex- and age-matched controls. Features reflecting differences in PSD curves were computed. A Lasso-regularized regression model was used to find an optimal feature subset, which was validated on 19 NC patients and 708 non-NC patients from a sleep clinic. Reproducible features were analyzed using receiver operating characteristic (ROC) curves. Thirteen features were selected based on the training dataset. Three were applicable in the validation dataset, indicating that NC patients show (1) increased alpha power in REM sleep, (2) decreased sigma power in wakefulness, and (3) decreased delta power in stage N1 versus wakefulness. Sensitivity of these features ranged from 4% to 10% with specificity around 98%, and it did not vary substantially with and without treatment. EEG spectral analysis of REM sleep, wake, and differences between N1 and wakefulness contain diagnostic features of NC. These traits may represent sleepiness and dissociated REM sleep in patients with NC. However, the features are not sufficient for differentiating NC from controls, and further analysis is needed to completely evaluate the diagnostic potential of these features. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Effect of clomipramine on sleep and EEG power spectra in the diurnal rodent Eutamias sibiricus

    NARCIS (Netherlands)

    Dijk, D.J.; Strijkstra, A.; Daan, S.; Beersma, D.G.M.; Hoofdakker, R.H. van den

    1991-01-01

    Sleep was recorded in the diurnal rodent Eutamias sibiricus, chronically implanted with EEG and EMG electrodes. The tricyclic antidepressant drug clomipramine suppressed the duration of REM sleep and EEG power density in the frequencies between 1.5 and 13.5 Hz in nonREM sleep. During the

  4. EEG power spectra of children with dyslexia, slow learners, and normally reading children with ADD during verbal processing.

    Science.gov (United States)

    Ackerman, P T; Dykman, R A; Oglesby, D M; Newton, J E

    1994-12-01

    EEG power spectra were studied in two poor reader groups (with dyslexia and slow learning) and a normally reading clinic control group (with attention deficit disorder) as the children viewed strings of words and letters (seven categories). The children ranged in age from 7.5 to 12 years; 33 were girls, 86 were boys. Bilateral temporal and parietal sites and four midline sites were used. The major difference between groups was in the low beta band, where the ADD group had greater power at the parietal and midline sites. Also, the slow learner group had marginally greater low beta at the left than right temporal site, with the opposite trend found for the dyslexic and ADD groups. Across groups, power was greater at the right than at the left parietal site in the delta and alpha bands and at the right than at the left temporal site in the low beta band. Stimulus category effects were modest, with some alpha suppression to word strings, relative to letter strings, found in the poor readers. In correlational analyses, the combination of greater low beta and less theta power significantly predicted better reading and spelling. Results indicate that the adequate readers more actively processed the stimuli than did the poor readers.

  5. Quantum chemical and experimental studies on the structure and vibrational spectra of an alkaloid-Corlumine

    Science.gov (United States)

    Mishra, Rashmi; Joshi, Bhawani Datt; Srivastava, Anubha; Tandon, Poonam; Jain, Sudha

    2014-01-01

    The study concentrates on an important natural product, phthalide isoquinoline alkaloid Corlumine (COR) [(6R)-6-[(1S)-1,2,3,4-Tetrahydro-6,7-dimethoxy-2-methylisoquinolin-1-yl] furo [3,4-e]-1,3-benzodioxol-8(6H)-one] well known to exhibit spasmolytic and GABA antagonist activity. It was fully characterized by a variety of experimental methods including vibrational spectroscopy (IR and Raman), thermal analysis (DSC), UV and SEM. For a better interpretation and analysis of the results quantum chemical calculations employing DFT were also performed. TD-DFT was employed to elucidate electronic properties for both gaseous and solvent environment using IEF-PCM model. Graphical representation of HOMO and LUMO would provide a valuable insight into the nature of reactivity and some of the structural and physical properties of the title molecule. The structure-activity relationship have been interpreted by mapping electrostatic potential surface (MEP), which is valuable information for the quality control of medicines and drug-receptor interactions. Stability of the molecule arising from hyper conjugative interactions, charge delocalisation has been analyzed using natural bond orbital (NBO) analysis. Computation of thermodynamical properties would help to have a deep insight into the molecule for further applications.

  6. Experimental study of rectenna coupling at low power level

    Science.gov (United States)

    Douyère, A.; Alicalapa, F.; Rivière, S.; Luk, J.-D. Lan Sun

    2013-04-01

    The experimental results presented in this paper focus on the performance of a rectenna array by studying the effect of mutual coupling between two rectennas. The measurements in several planes of the space are investigated and used to help us to define the minimum distance for future rectenna arrays that can be used at a low power density level. The single element chosen for the array is composed of a rectifier circuit and a CSPA (Circular Slot Patch Antenna). This study shows that at a distance greater than 6cm (λ/2) between two rectennas in reception, we observe that the DC received voltage is constant in the Y plane, while in the X plane, the DC received voltage remains constant whatever the distance. We deduce that these rectennas are uncoupled in this case. We can consider each rectenna like an independent system.

  7. Analysis of longer period variation of the Kuroshio Current intrusion into the Luzon Strait using rectified wavelet power spectra

    Science.gov (United States)

    Yuan, Yaochu; Yang, Chenghao; Tseng, Yu-heng; Zhu, Xiao-Hua; Wang, Huiqun; Chen, Hong

    2017-08-01

    Longer period variation of the Kuroshio into the Luzon Strait (LS) was identified using acoustic Doppler current profiler (ADCP) observations as well as pressure and temperature time series data recorded by two TDs (manufactured by the RBR Ltd.) at mooring station N2 (20°40.441‧N, 120°38.324‧E). The ADCP was deployed at depths of 50-300 m between July 7, 2009 and April 10, 2011, and the TDs at around 340 and 365 m between July 9, 2009 and July 9, 2011. Observations provide strong evidence of longer period variation of the Kuroshio into the LS using the Vector rotary spectra (VRS) and Rectified wavelet power spectra analysis (RWPSA). RWPSA of the observations allowed the identification of two types of dominant periods. The first type, with the strongest power spectral density (PSD), had a dominant period of 112 d and was found throughout the upper 300 m. For example, the maximum PSD for western and northern velocity components time series were 3800 and 3550 at 50 m, respectively. The maximum power spectral density decrease with deeper depths, i.e., the depth dependence of maximum PSD. The 112 d period was also identified in the pressure and temperature time series data, at 340 m and 365 m. Combined RWPSA with VRS and mechanism analysis, it is clear that the occurrence of the most dominant period of 112 d in the upper 300 m is related to the clockwise meandering of the Kuroshio into the LS, which is caused by westward propagating stronger anticyclonic eddies from the interior ocean due to the interaction of Rossby eddies with the Kuroshio. The second type of dominant period, for example a 40 d period, is related to the anticlockwise meandering of the Kuroshio. The final dominant period of 14 d coincides with the fortnightly spring-neap tidal period.

  8. Structure in the 3D Galaxy Distribution. III. Fourier Transforming the Universe: Phase and Power Spectra

    Science.gov (United States)

    Scargle, Jeffrey D.; Way, M. J.; Gazis, P. G.

    2017-01-01

    We demonstrate the effectiveness of a relatively straightforward analysis of the complex 3D Fourier transform of galaxy coordinates derived from redshift surveys. Numerical demonstrations of this approach are carried out on a volume-limited sample of the Sloan Digital Sky Survey redshift survey. The direct unbinned transform yields a complex 3D data cube quite similar to that from the Fast Fourier Transform of finely binned galaxy positions. In both cases, deconvolution of the sampling window function yields estimates of the true transform. Simple power spectrum estimates from these transforms are roughly consistent with those using more elaborate methods. The complex Fourier transform characterizes spatial distributional properties beyond the power spectrum in a manner different from (and we argue is more easily interpreted than) the conventional multipoint hierarchy. We identify some threads of modern large-scale inference methodology that will presumably yield detections in new wider and deeper surveys.

  9. Reaction rates and neutron spectra in the FFTF at full power

    Energy Technology Data Exchange (ETDEWEB)

    Wootan, D.W.; Rawlins, J.A.; Dobbin, K.D.

    1984-05-01

    Results from the HP irradiation test have been shown to reduce uncertainties associated with calculation of axial and radial flux and reaction rate distributions, flux perturbations due to core heterogeneities, neutron flux and reaction rates outside the fuel region, activation of structural components and sodium, and fuel burnup. Improved knowledge of reaction rates (hence burnup, power and flux distributions) is expected to result in better prediction of the performance of experiments irradiated in FFTF.

  10. Tokamak experimental power reactor conceptual design. Volume I

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    A conceptual design has been developed for a tokamak Experimental Power Reactor to operate at net electrical power conditions with a plant capacity factor of 50 percent for 10 years. The EPR operates in a pulsed mode at a frequency of approximately 1/min., with an approximate 75 percent duty cycle, is capable of producing approximately 72 MWe and requires 42 MWe. The annual tritium consumption is 16 kg. The EPR vacuum chamber is 6.25 m in major radius and 2.4 m in minor radius, is constructed of 2-cm thick stainless steel, and has 2-cm thick detachable, beryllium-coated coolant panels mounted on the interior. An 0.28 m stainless steel blanket and a shield ranging from 0.6 to 1.0 m surround the vacuum vessel. The coolant is H/sub 2/O. Sixteen niobium-titanium superconducting toroidal-field coils provide a field of 10 T at the coil and 4.47 T at the plasma. Superconducting ohmic-heating and equilibrium-field coils provide 135 V-s to drive the plasma current. Plasma heating is accomplished by 12 neutral beam-injectors, which provide 60 MW. The energy transfer and storage system consists of a central superconducting storage ring, a homopolar energy storage unit, and a variety of inductor-converters.

  11. Comparison of calculated and experimental isotope edited FTIR difference spectra for purple bacterial photosynthetic reaction centers with different quinones incorporated into the QA binding site.

    Directory of Open Access Journals (Sweden)

    Nan eZhao

    2013-08-01

    Full Text Available Previously we have shown that ONIOM type (QM/MM calculations can be used to simulate isotope edited FTIR difference spectra for neutral ubiquinone in the QA binding site in Rhodobacter sphaeroides photosynthetic reaction centers. Here we considerably extend upon this previous work by calculating isotope edited FTIR difference spectra for reaction centers with a variety of unlabeled and 18O labeled foreign quinones incorporated into the QA binding site. Isotope edited spectra were calculated for reaction centers with 2,3-dimethoxy-5,6-dimethyl-1,4-benzoquinone (MQ0, 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ, and 2,3-dimethyl-l,4-naphthoquinone (DMNQ incorporated, and compared to corresponding experimental spectra. The calculated and experimental spectra agree well, further demonstrating the utility and applicability of our ONIOM approach for calculating the vibrational properties of pigments in protein binding sites.The normal modes that contribute to the bands in the calculated spectra, their composition, frequency and intensity, and how these quantities are modified upon 18O labeling, are presented. This computed information leads to a new and more detailed understanding/interpretation of the experimental FTIR difference spectra. Hydrogen bonding to the carbonyl groups of the incorporated quinones is shown to be relatively weak. It is also shown that there is some asymmetry in hydrogen bonding, accounting for 10-13 cm-1 separation in the frequencies of the carbonyl vibrational modes of the incorporated quinones. The extent of asymmetry H-bonding could only be established by considering the spectra for various types of quinones incorporated into the QA binding site. The quinones listed above are tail-less. Spectra were also calculated for reaction centers with corresponding tail containing quinones incorporated, and it is found that replacement of the quinone methyl group by a phytyl or prenyl chain does not alter ONIOM calculated s

  12. Experimental diagnostics and modeling of inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells

    Science.gov (United States)

    Pivac, Ivan; Šimić, Boris; Barbir, Frano

    2017-10-01

    Representation of fuel cell processes by equivalent circuit models, involving resistance and capacitance elements representing activation losses on both anode and cathode in series with resistance representing ohmic losses, cannot capture and explain the inductive loop that may show up at low frequencies in Nyquist diagram representation of the electrochemical impedance spectra. In an attempt to explain the cause of the low-frequency inductive loop and correlate it with the processes within the fuel cell electrodes, a novel equivalent circuit model of a Proton Exchange Membrane (PEM) fuel cell has been proposed and experimentally verified here in detail. The model takes into account both the anode and the cathode, and has an additional resonant loop on each side, comprising of a resistance, capacitance and inductance in parallel representing the processes within the catalyst layer. Using these additional circuit elements, more accurate and better fits to experimental impedance data in the wide frequency range at different current densities, cell temperatures, humidity of gases, air flow stoichiometries and backpressures were obtained.

  13. Synchrotron Polarization and Synchrotron Self-absorption Spectra for a Power-law Particle Distribution with Finite Energy Range

    Science.gov (United States)

    Fouka, M.; Ouichaoui, S.

    2011-12-01

    We have derived asymptotic forms for the degree of polarization of the optically thin synchrotron and for synchrotron self-absorption (SSA) spectra assuming a power-law particle distribution of the form N(γ) ~ γ-p with γ1 Lambert W function based on the analytical asymptotic form of the absorption coefficient, αν, for the high-frequency range ν Gt ν2 (with ν2 the synchrotron frequency corresponding to γ2). We have shown that the latter frequency may not have realistic applications in astrophysics, except in the case of an adequate set of parameters allowing one to neglect Comptonization effects. More detailed calculations and discussions are presented.

  14. CALCLENS: weak lensing simulations for large-area sky surveys and second-order effects in cosmic shear power spectra

    Science.gov (United States)

    Becker, Matthew R.

    2013-10-01

    I present a new algorithm, Curved-sky grAvitational Lensing for Cosmological Light conE simulatioNS (CALCLENS), for efficiently computing weak gravitational lensing shear signals from large N-body light cone simulations over a curved sky. This new algorithm properly accounts for the sky curvature and boundary conditions, is able to produce redshift-dependent shear signals including corrections to the Born approximation by using multiple-plane ray tracing and properly computes the lensed images of source galaxies in the light cone. The key feature of this algorithm is a new, computationally efficient Poisson solver for the sphere that combines spherical harmonic transform and multigrid methods. As a result, large areas of sky (˜10 000 square degrees) can be ray traced efficiently at high resolution using only a few hundred cores. Using this new algorithm and curved-sky calculations that only use a slower but more accurate spherical harmonic transform Poisson solver, I study the convergence, shear E-mode, shear B-mode and rotation mode power spectra. Employing full-sky E/B-mode decompositions, I confirm that the numerically computed shear B-mode and rotation mode power spectra are equal at high accuracy (≲1 per cent) as expected from perturbation theory up to second order. Coupled with realistic galaxy populations placed in large N-body light cone simulations, this new algorithm is ideally suited for the construction of synthetic weak lensing shear catalogues to be used to test for systematic effects in data analysis procedures for upcoming large-area sky surveys. The implementation presented in this work, written in C and employing widely available software libraries to maintain portability, is publicly available at http://code.google.com/p/calclens.

  15. Effects of argon sparging rate, ultrasonic power, and frequency on multibubble sonoluminescence spectra and bubble dynamics in NaCl aqueous solutions.

    Science.gov (United States)

    Cairós, Carlos; Schneider, Julia; Pflieger, Rachel; Mettin, Robert

    2014-11-01

    The sonoluminescence spectra from acoustic cavitation in aqueous NaCl solutions are systematically studied in a large range of ultrasonic frequencies under variation of electrical power and argon sparging. At the same time, bubble dynamics are analysed by high-speed imaging. Sodium line and continuum emission are evaluated for acoustic driving at 34.5, 90, 150, 365, and 945kHz in the same reactor vessel. The results show that the ratio of sodium line to continuum emission can be shifted by the experimental parameters: an increase in the argon flow increases the ratio, while an increase in power leads to a decrease. At 945kHz, the sodium line is drastically reduced, while the continuum stays at elevated level. Bubble observations reveal a remarkable effect of argon in terms of bubble distribution and stability: larger bubbles of non-spherical shapes form and eject small daughter bubbles which in turn populate the whole liquid. As a consequence, the bubble interactions (splitting, merging) appear enhanced which supports a link between non-spherical bubble dynamics and sodium line emission. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Comparison of Blade Element Momentum Theory to Experimental Data Using Experimental Lift, Drag, and Power Data

    Science.gov (United States)

    Nealon, Tara; Miller, Mark; Kiefer, Janik; Hultmark, Marcus

    2016-11-01

    Blade Element Momentum (BEM) codes have often been used to simulate the power output and loads on wind turbine blades without performing CFD. When computing the lift and drag forces on the blades, the coefficients of lift and drag are normally calculated by interpolating values from standard airfoil data based on the angle of attack. However, there are several empirical corrections that are needed. Due to a lack of empirical data to compare against, the accuracy of these corrections and BEM in general is still not well known. For this presentation, results from an in-house written BEM code computed using experimental lift and drag coefficient data for the airfoils of the V27 wind turbine will be presented. The data is gathered in Princeton University's High Reynolds Number Testing Facility (HRTF) at full scale Reynolds numbers and over a large range of angles of attack. The BEM results are compared to experimental data of the same wind turbine, conducted at full scale Reynolds number and TSR, also in the HRTF. Conclusions will be drawn about the accuracy of the BEM code, and the corrections, regarding the usage of standard airfoil data versus the experimental data, as well as future applications to potentially improve large-eddy simulations of wind turbines in a similar manner.

  17. Accounting for reconstruction kernel-induced variability in CT radiomic features using noise power spectra.

    Science.gov (United States)

    Shafiq-Ul-Hassan, Muhammad; Zhang, Geoffrey G; Hunt, Dylan C; Latifi, Kujtim; Ullah, Ghanim; Gillies, Robert J; Moros, Eduardo G

    2018-01-01

    Large variability in computed tomography (CT) radiomics feature values due to CT imaging parameters can have subsequent implications on the prognostic or predictive significance of these features. Here, we investigated the impact of pitch, dose, and reconstruction kernel on CT radiomic features. Moreover, we introduced correction factors to reduce feature variability introduced by reconstruction kernels. The credence cartridge radiomics and American College of Radiology (ACR) phantoms were scanned on five different scanners. ACR phantom was used for 3-D noise power spectrum (NPS) measurements to quantify correlated noise. The coefficient of variation (COV) was used as the variability assessment metric. The variability in texture features due to different kernels was reduced by applying the NPS peak frequency and region of interest (ROI) maximum intensity as correction factors. Most texture features were dose independent but were strongly kernel dependent, which is demonstrated by a significant shift in NPS peak frequency among kernels. Percentage improvement in robustness was calculated for each feature from original and corrected %COV values. Percentage improvements in robustness of 19 features were in the range of 30% to 78% after corrections. We show that NPS peak frequency and ROI maximum intensity can be used as correction factors to reduce variability in CT texture feature values due to reconstruction kernels.

  18. Power spectra in warm G inflation and its consistency: Stochastic approach

    Science.gov (United States)

    Motaharfar, Meysam; Massaeli, Erfan; Sepangi, Hamid Reza

    2017-11-01

    Recently, it has been realized that the so-called G -inflation model inspired by supplementing a generalized covariant Galileon-like nonlinear derivative self-interacting term to the standard kinetic term should be ruled out from inflationary models. This is due to the fact that it suffers from lack of an oscillatory phase at the end of the inflationary regime which is typically accompanied by the appearance of a negative squared propagation speed of the scalar mode leading to instabilities of small-scale perturbations. In this regard, the warm G -inflation scenario is proposed where for G inflation to survive, the Galileon scalar field is coupled to the radiation field through a dissipation term which results in removing the reheating period due to the characteristics of warm inflationary scenario. In so doing, a linear stability analysis is first performed to obtain the appropriate slow-roll conditions in such a proposal. Cosmological perturbations of the model are then investigated by utilizing a fluctuation-dissipation theorem and analytical expressions are derived for observable quantities; the power spectrum, tilt spectral index, and tensor-to-scalar ratio in terms of P S R parameters and Galileon flow functions. Finally, the model is solved for chaotic self-interacting potentials, particularly the renormalizable Higgs potential λ/4 ϕ4, and shown to be consistent with observations in the weak dissipation Q ≪1 +3 δ/GXδX and G -dominant 3 δ/GXδX≫1 regime despite its large self-coupling, since the energy scale at the horizon crossing is depressed by the synergy of Galileon and thermal effects.

  19. Amphetamine and haloperidol modulatory effects on Purkinje cell activity and on EEG power spectra in the acute rat model of epilepsy.

    Science.gov (United States)

    Culić, M; Saponjić, J; Janković, B; Rakić, L

    1994-12-05

    The modulation of cerebellar Purkinje cell activity and EEG from parietal cortex was studied in the rat model of epilepsy induced by penicillin under acute haloperidol and amphetamine treatment. The discharge pattern of Purkinje cells showed tendency towards inhibition and EEG power spectra increased after parenteral administration of penicillin (1000000 IU/kg, i.p.). Acute haloperidol treatment (1 mg/kg, i.p.), performed after the development of penicillin induced epileptic episodes, elicited a prominent excitation of Purkinje cell discharges associated with parallel increase in mean EEG power spectra. However, acute DL-amphetamine treatment induced marked suppression of Purkinje cell discharges as well as outstanding decrease of the mean EEG power spectra. These results indicate that cerebellar Purkinje cells may be important in the control of seizure activity and that noradrenergic influences are relevant.

  20. FTIR and Raman spectra of CH(D)FClsbnd CF2sbnd Osbnd CHF derivatives of enflurane. Experimental and ab initio study

    Science.gov (United States)

    Melikova, S. M.; Rutkowski, K. S.; Telkova, E.; Czarnik-Matusewicz, B.; Rospenk, M.; Herrebout, W.

    2015-05-01

    The vibrational spectra of two H/D derivatives of enflurane are studied with the help of FTIR cryospectroscopy in liquefied Kr and Raman spectroscopy of pure liquid. The majority of fundamental bands are identified. Using MP2/6-311++G(df,pd) calculations the six local minima are found on the potential energy surface and ascribed to the most stable conformers of enflurane. The vibrational frequencies, infrared intensities, and Raman activities are found at the same level of theory. The potential energy distribution is calculated for the most stable conformer. Assignment of the vibrational bands registered is performed using the results of calculations of the frequencies with "anharm" option implemented in Gaussian. The model IR and Raman spectra built with the help of data of ab initio calculations reflect the basic features of experimental spectra. IR spectra of cryosolutions of enflurane and acetone in liquefied Kr suggest weak complex formation stabilized by "blue shifting" H bonds.

  1. Antioxidant activity, NMR, X-ray, ECD and UV/vis spectra of (+)-terrein: Experimental and theoretical approaches

    Science.gov (United States)

    Trabolsy, Zuhra Bashir Khalifa Al; Anouar, El Hassane; Zakaria, Nur Shahidatul Shida; Zulkeflee, Manar; Hasan, Mizaton Hazizul; Zin, Maisarah Mohd; Ahmad, Rohaya; Sultan, Sadia; Weber, Jean-Frédéric F.

    2014-02-01

    Fungal metabolite terrein isolated from Aspergillus terreus is endowed with diverse biological and antioxidant activities. To determine the stereochemistry of the isolated terrein, we combined spectroscopic methods (CD and NMR spectra) and theoretical calculations (DFT and TD-DFT methods). Stereochemistry effects on the antioxidant activity of isolated terrein were evaluated by calculating bond dissociation enthalpies (BDEs), ionization potentials (IPs) and spin density delocalization of terrein and isoterrein stereoisomers with B3P86/6-31+G (d, p) method in gas and polarizable continuum model. The results showed a good agreement between experimental data and theoretical calculations which confirmed the (+)-terrein stereochemistry of isolated metabolite. Theoretical calculations showed that the antioxidant activity is relatively influenced by isomeric geometry of the terrein (a variation of 2 kcal/mol between BDEs of terrein and isoterrein isomers), while chirality has no influence on the antioxidant activity [0.2 kcal/mol difference between BDEs of (+)- and (-)-terrein]. The low antioxidant activity of (+)-terrein with respect to trolox and ascorbic acid was explained by the positive free Gibbs energy of the hydrogen atom transfer (HAT) mechanism and high BDE values of the 2-OH active site.

  2. Solar-Powered Desalination: A Modelling and Experimental Study

    Science.gov (United States)

    Leblanc, Jimmy; Andrews, John

    2007-10-01

    Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger

  3. Regular cannabis and alcohol use is associated with resting-state time course power spectra in incarcerated adolescents.

    Science.gov (United States)

    Thijssen, Sandra; Rashid, Barnaly; Gopal, Shruti; Nyalakanti, Prashanth; Calhoun, Vince D; Kiehl, Kent A

    2017-09-01

    Cannabis and alcohol are believed to have widespread effects on the brain. Although adolescents are at increased risk for substance use, the adolescent brain may also be particularly vulnerable to the effects of drug exposure due to its rapid maturation. Here, we examined the association between cannabis and alcohol use duration and resting-state functional connectivity in a large sample of male juvenile delinquents. The present sample was drawn from the Southwest Advanced Neuroimaging Cohort, Youth sample, and from a youth detention facility in Wisconsin. All participants were scanned at the maximum-security facilities using The Mind Research Network's 1.5T Avanto SQ Mobile MRI scanner. Information on cannabis and alcohol regular use duration was collected using self-report. Resting-state networks were computed using group independent component analysis in 201 participants. Associations with cannabis and alcohol use were assessed using Mancova analyses controlling for age, IQ, smoking and psychopathy scores in the complete case sample of 180 male juvenile delinquents. No associations between alcohol or cannabis use and network spatial maps were found. Longer cannabis use was associated with decreased low frequency power of the default mode network, the executive control networks (ECNs), and several sensory networks, and with decreased functional network connectivity. Duration of alcohol use was associated with decreased low frequency power of the right frontoparietal network, salience network, dorsal attention network, and several sensory networks. Our findings suggest that adolescent cannabis and alcohol use are associated with widespread differences in resting-state time course power spectra, which may persist even after abstinence. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Experimental investigation of solar powered diaphragm and helical pumps

    Science.gov (United States)

    For several years, many types of solar powered water pumping systems were evaluated, and in this paper, diaphragm and helical solar photovoltaic (PV) powered water pumping systems are discussed. Data were collected on diaphragm and helical pumps which were powered by different solar PV arrays at mul...

  5. Experimental Investigation on Power Output in Aged Wind Turbines

    Directory of Open Access Journals (Sweden)

    N. Murugan

    2012-01-01

    Full Text Available An investigation on the power output on effect of tower height with same diameter of rotor was conducted in a wind turbine site. As the wind acceleration is varying with height, 3 levels were selected according to the availability of tower. The responses of power output with respect to variation of wind speed are changing for the tower heights of 30, 40, and 50 m. The study showed that the actual ideal power output and measured real power output follow the same trend within range of operating wind speed. The empirical model used for calculation of actual ideal power output was compared with real power output and the overall concepts in power output also had been analysed.

  6. Power spectra based Planck constraints on compensated isocurvature, and forecasts for LiteBIRD and CORE space missions

    Science.gov (United States)

    Väliviita, Jussi

    2017-04-01

    Compensated isocurvature perturbations (CIP), where the primordial baryon and cold dark matter density perturbations cancel, do not cause total matter isocurvature perturbation. Consequently, at the linear order in the baryon density contrast Δ, a mixture of CIP and the adiabatic mode leads to the same CMB spectra as the pure adiabatic mode. Only recently, Muñoz et al. showed that at the second order CIP leaves an imprint in the observable CMB by smoothing the power spectra in a similar manner as lensing. This causes a strong degeneracy between the CIP variance Δrms2 ≡ langleΔ2rangle and the phenomenological lensing parameter AL. We study several combinations of the Planck 2015 data and show that the measured lensing potential power spectrum Clphiphi breaks the degeneracy. Nested sampling of the ΛCDM+Δrms2(+AL) model using the Planck 2015 temperature, polarization, and lensing data gives Δrms2 = (6.9+3.0-3.1) × 10-3 at 68% CL. A non-zero value is favoured at 2.3σ (or without the polarization data at 2.8σ). CIP with Δrms2 ≈ 7 × 10-3 improves the bestfit χ2 by 3.6 compared to the adiabatic ΛCDM model. In contrast, although the temperature data favour AL simeq 1.22, allowing AL ≠ 1 does not improve the joint fit at all, since the lensing data disfavour AL ≠ 1. Indeed, CIP provides a rare example of a simple model, which is capable of reducing the Planck lensing anomaly significantly and fitting well simultaneously the high (and low) multipole temperature and lensing data, as well as the polarization data. Finally, we derive forecasts for two future satellite missions (LiteBIRD proposal to JAXA/NASA and Exploring Cosmic Origins with CORE proposal to ESA's M5 call) and compare these to simulated Planck data. Due to its coarse angular resolution, LiteBIRD is not able to improve the constraints on Δrms2 or AL, but CORE-M5 (almost) reaches the cosmic variance limit and improves the CIP constraint to Δrms2 CORE-M5 will exquisitely distinguish between

  7. A neuronal network model for simulating the effects of repetitive transcranial magnetic stimulation on local field potential power spectra.

    Directory of Open Access Journals (Sweden)

    Alina Bey

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS holds promise as a non-invasive therapy for the treatment of neurological disorders such as depression, schizophrenia, tinnitus, and epilepsy. Complex interdependencies between stimulus duration, frequency and intensity obscure the exact effects of rTMS stimulation on neural activity in the cortex, making evaluation of and comparison between rTMS studies difficult. To explain the influence of rTMS on neural activity (e.g. in the motor cortex, we use a neuronal network model. The results demonstrate that the model adequately explains experimentally observed short term effects of rTMS on the band power in common frequency bands used in electroencephalography (EEG. We show that the equivalent local field potential (eLFP band power depends on stimulation intensity rather than on stimulation frequency. Additionally, our model resolves contradictions in experiments.

  8. Spectra and depth-dose deposition in a polymethylmethacrylate breast phantom obtained by experimental and Monte Carlo method; Espectros e deposicao de dose em profundidade em phantom de mama de polimetilmetacrilato: obtencao experimental e por metodo de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    David, Mariano G.; Pires, Evandro J.; Magalhaes, Luis A.; Almeida, Carlos E. de; Alves, Carlos F.E., E-mail: marianogd08@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Lab. Ciencias Radiologicas; Albuquerque, Marcos A. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Instituto Alberto Luiz Coimbra; Bernal, Mario A. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin; Peixoto, Jose G. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2012-08-15

    This paper focuses on the obtainment, using experimental and Monte Carlo-simulated (MMC) methods, of the photon spectra at various depths and depth-dose deposition curves for x-rays beams used in mammography, obtained on a polymethylmethacrylate (PMMA) breast phantom. Spectra were obtained for 28 and 30 kV quality-beams and the corresponding average energy values (Emed) were calculated. For the experimental acquisition was used a Si-PIN photodiode spectrometer and for the MMC simulations the PENELOPE code was employed. The simulated and the experimental spectra show a very good agreement, which was corroborated by the low differences found between the Emed values. An increase in the Emed values and a strong attenuation of the beam through the depth of the PMMA phantom was also observed. (author)

  9. Emotion classification in Parkinson's disease by higher-order spectra and power spectrum features using EEG signals: a comparative study.

    Science.gov (United States)

    Yuvaraj, R; Murugappan, M; Ibrahim, Norlinah Mohamed; Omar, Mohd Iqbal; Sundaraj, Kenneth; Mohamad, Khairiyah; Palaniappan, R; Satiyan, M

    2014-03-01

    Deficits in the ability to process emotions characterize several neuropsychiatric disorders and are traits of Parkinson's disease (PD), and there is need for a method of quantifying emotion, which is currently performed by clinical diagnosis. Electroencephalogram (EEG) signals, being an activity of central nervous system (CNS), can reflect the underlying true emotional state of a person. This study applied machine-learning algorithms to categorize EEG emotional states in PD patients that would classify six basic emotions (happiness and sadness, fear, anger, surprise and disgust) in comparison with healthy controls (HC). Emotional EEG data were recorded from 20 PD patients and 20 healthy age-, education level- and sex-matched controls using multimodal (audio-visual) stimuli. The use of nonlinear features motivated by the higher-order spectra (HOS) has been reported to be a promising approach to classify the emotional states. In this work, we made the comparative study of the performance of k-nearest neighbor (kNN) and support vector machine (SVM) classifiers using the features derived from HOS and from the power spectrum. Analysis of variance (ANOVA) showed that power spectrum and HOS based features were statistically significant among the six emotional states (p emotions (sadness, fear, anger and disgust) than in processing of positive emotions (happiness, surprise) compared with HC. These results demonstrate the effectiveness of applying machine learning techniques to the classification of emotional states in PD patients in a user independent manner using EEG signals. The accuracy of the system can be improved by investigating the other HOS based features. This study might lead to a practical system for noninvasive assessment of the emotional impairments associated with neurological disorders.

  10. Experimental infrared spectra of Cl-(ROH) (R = H, CH3, CH3CH2) complexes in the gas-phase.

    Science.gov (United States)

    Fridgen, Travis D; McMahon, Terry B; Maître, Philippe; Lemaire, Joel

    2006-06-07

    Infrared multiple photon dissociation spectra for the chloride ion solvated by either water, methanol or ethanol have been recorded using an FTICR spectrometer coupled to a free-electron laser, and are presented here along with assignments to the observed bands. The assignments made to the Cl(-)/H(2)O, Cl(-)(CH(3)OH), and Cl(-)(CH(3)CH(2)OH) spectra are based on comparison with the neutral H(2)O, CH(3)OH, and CH(3)CH(2)OH spectra, respectively. This work confirms that a band observed around 1400 cm(-1) in the Cl(-)(H(2)O) spectrum is not due to the Ar tag in Ar predissociation spectra. The carrier of this band is, most likely, the first overtone of the OHCl bend. Based on the position of the overtone in the IRMPD spectrum, 1375 cm(-1), the fundamental must occur very close to 700 cm(-1) and observation of this band should aid theoretical treatments of the spectrum of this complex. B3LYP/6-311++G(2df,2pd) calculations are shown to reproduce the IRMPD spectra of all three solvated chloride species. They also predict that attaching one or two Ar atoms to the Cl(-)(H(2)O) complex results in a shift of no more than a few wavenumbers in the fundamental bands for the bare complex, in agreement with previous experiment. For both alcohol-Cl(-) complexes, the S(N)2 "backside attack" isomers are not observed and Cl(-) is predicted theoretically, and confirmed experimentally, to be bound to the hydroxyl hydrogen. For Cl(-)(CH(3)CH(2)OH), the trans and gauche conformers are similar in energy, with the gauche conformer predicted to be thermodynamically favoured. The experimental infrared spectrum agrees well with that predicted for the gauche conformer but a mixture of gauche and anti conformers cannot be ruled out based on the experimental spectra nor on the computed thermochemistry.

  11. Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults.

    Science.gov (United States)

    Choi, Jong-Bae; Lee, Yu-Jin G; Jeong, Do-Un

    2017-07-01

    The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. The night with nicotine patch showed significant increase in sleep latency, wake after sleep onset, and stage 1 sleep; and decrease in total sleep time, sleep efficiency, and percentage of REM sleep. Also, spectral analysis of the sleep EEG in the night with nicotine patch revealed decreased slow wave activity in stage 2 and REM sleep and increased alpha activity in the first NREM-REM sleep cycle. Heart rate variability showed no differences between the 2 nights, but the low to high ratio (a parameter indicative of sympathetic nervous system activity) positively correlated with wake after sleep onset in night with nicotine patch. Transdermal nicotine patch significantly disrupts sleep continuity, sleep architecture, and homeostatic sleep propensity. The overactivation of the sympathetic nervous system may be responsible for these changes.

  12. Structure determination of small vanadium clusters by density-functional theory in comparison with experimental far-infrared spectra.

    Science.gov (United States)

    Ratsch, C; Fielicke, A; Kirilyuk, A; Behler, J; von Helden, G; Meijer, G; Scheffler, M

    2005-03-22

    The far-infrared vibrational spectra for charged vanadium clusters with sizes of 3-15 atoms have been measured using infrared multiple photon dissociation of Vn+Ar-->Vn(+)+Ar. Using density-functional theory calculations, we calculated the ground state energy and vibrational spectra for a large number of stable and metastable geometries of such clusters. Comparison of the calculated vibrational spectra with those obtained in the experiment allows us to deduce the cluster size specific atomic structures. In several cases, a unique atomic structure can be identified, while in other cases our calculations suggest the presence of multiple isomers.

  13. Solar power plant performance evaluation: simulation and experimental validation

    Science.gov (United States)

    Natsheh, E. M.; Albarbar, A.

    2012-05-01

    In this work the performance of solar power plant is evaluated based on a developed model comprise photovoltaic array, battery storage, controller and converters. The model is implemented using MATLAB/SIMULINK software package. Perturb and observe (P&O) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The outcome of the developed model are validated and supported by a case study carried out using operational 28.8kW grid-connected solar power plant located in central Manchester. Measurements were taken over 21 month's period; using hourly average irradiance and cell temperature. It was found that system degradation could be clearly monitored by determining the residual (the difference) between the output power predicted by the model and the actual measured power parameters. It was found that the residual exceeded the healthy threshold, 1.7kW, due to heavy snow in Manchester last winter. More important, the developed performance evaluation technique could be adopted to detect any other reasons that may degrade the performance of the P V panels such as shading and dirt. Repeatability and reliability of the developed system performance were validated during this period. Good agreement was achieved between the theoretical simulation and the real time measurement taken the online grid connected solar power plant.

  14. Experimental study on the influence of the contact pressure to transmittance and reflectance spectra by near infrared spectroscopy

    Science.gov (United States)

    Jiang, Jingying; Li, Si; Wang, Tianpei; Li, Lin; Liu, Jiajia; Xu, Kexin

    2017-03-01

    Near Infrared Spectroscopy (NIRS) technology has been recognized as one of the most promising non-invasive blood glucose measurement methods due to its convenience, high efficiency, noninvasiveness, and real-time monitoring. We build a system to measure transmittance and reflectance within NIR range simultaneously. And contact measuring method has been performed in order to reduce the influence of specular reflectance of the measured skin tissue. However, in this way, the optical probe could press the skin tissue and make it distorted, which might make the internal structure and the constituent distribution of tissue changed and further the tissue optical parameter changed. This could eventually change the distribution of transmittance spectra and reflectance spectra. In this talk, we collect the transmittance spectra and the diffused reflectance spectra of human earlobe within the wavelength of 900-1700nm under the different contact pressures. The results show that the diffused reflectance spectra decrease and the diffused transmittance spectra increase with the increase of the contact pressure between the probe and the earlobe. In order to improve the precision and stability of NIRS, the contact position of the deformation of 0.75mm is determined to be an optimal contact state measurement position.

  15. Experimental and Analytical Power Flow in Beams Using a Scanning Laser Doppler Vibrometer

    Directory of Open Access Journals (Sweden)

    Jonathan D. Blotter

    1996-01-01

    Full Text Available An experimental spatial power-flow (ESPF method is presented. This method provides a spatially continuous model of the power-flow vector field derived from experimental measurements. The power-flow vector field clearly indicates locations of energy sources and sinks as well as paths of energy transmission. In the ESPF approach, a scanning laser Doppler vibrometer acquires spatially dense measurements of the vibrating test structure. These measurements are used in solving for a spatially continuous 3-dimensional complex-valued model of the steady-state dynamic response. From this experimentally derived dynamics model, a spatial representation of the power flow is computed.

  16. An Experimental Analysis of Asymmetric Power in Conflict Bargaining

    Directory of Open Access Journals (Sweden)

    William Reed

    2013-08-01

    Full Text Available Demands and concessions in a multi-stage bargaining process are shaped by the probabilities that each side will prevail in an impasse. Standard game-theoretic predictions are quite sharp: demands are pushed to the precipice with nothing left on the table, but there is no conflict regardless of the degree of power asymmetry. Indeed, there is no delay in reaching an agreement that incorporates the (unrealized costs of delay and conflict. A laboratory experiment has been used to investigate the effects of power asymmetries on conflict rates in a two-stage bargaining game that is (if necessary followed by conflict with a random outcome. Observed demands at each stage are significantly correlated with power, as measured by the probability of winning in the event of disagreement. Demand patterns, however, are flatter than theoretical predictions, and conflict occurs in a significant proportion of the interactions, regardless of the degree of the power asymmetry. To address these deviations from the standard game-theoretic predictions, we also estimated a logit quantal response model, which generated the qualitative patterns that are observed in the data. This one-parameter generalization of the Nash equilibrium permits a deconstruction of the strategic incentives that cause demands to be less responsive to power asymmetries than Nash predictions.

  17. Power module for an experimental picosatellite Cubesat type

    Directory of Open Access Journals (Sweden)

    Javier Castro Avellaneda

    2016-06-01

    Full Text Available This article describes a power module for picosatellite following CubeSat standard requirements [1,2,3,13]. The Power Module project is developed in four phases: study, design, implementation and testing. In the study phase of the theoretical framework and preliminary designs made in the Universidad Distrital [4,5] and other CubeSat developed in the world is reviewed, also investigates existing technologies and components in the market and its affordability. The design phase involves analysis of the system and using a computer program designed to generate the necessary hardware. The ultimate goal is to obtain a functional power module and work in space environment conditions in which the picosatellite keep his focus on an application in telemedicine, with a payload that would become the telecommunications system mission.

  18. Experimental validation of waveform relaxation technique for power ...

    Indian Academy of Sciences (India)

    To demonstrate practical feasibility of the WR scheme, this paper presents results of experiments with real-time implementation of controllers, iteratively interacting with simulated models of power apparatus via storage and real-time play-back. Two systems are considered: a HVDC controller tested with a detailed model of ...

  19. Binding modes of phosphonic acid derivatives adsorbed on TiO2 surfaces: Assignments of experimental IR and NMR spectra based on DFT/PBC calculations

    Science.gov (United States)

    Geldof, D.; Tassi, M.; Carleer, R.; Adriaensens, P.; Roevens, A.; Meynen, V.; Blockhuys, F.

    2017-01-01

    A DFT study on the adsorption of a series of phosphonic acids (PAs) on the TiO2 anatase (101) and (001) surfaces was performed. The adsorption energies and geometries of the most stable binding modes were compared to literature data and the effect of the inclusion of dispersion forces in the energy calculations was gauged. As the (101) surface is the most exposed surface of TiO2 anatase, the calculated chemical shifts and vibrational frequencies of PAs adsorbed on this surface were compared to experimental 31P and 17O NMR and IR data in order to assign the two possible binding modes (mono- and bidentate) to peaks and bands in these spectra; due to the corrugated nature of anatase (101) tridentate binding is not possible on this surface. Analysis of the calculated and experimental 31P chemical shifts indicates that both monodentate and bidentate binding modes are present. For the reactive (001) surface, the results of the calculations indicate that both bi- and tridentate binding modes result in stable systems. Due to the particular sensitivity of 17O chemical shifts to hydrogen bonding and solvent effects, the model used is insufficient to assign these spectra at present. Comparison of calculated and experimental IR spectra leads to the conclusion that IR spectroscopy is not suitable for the characterization of the different binding modes of the adsorption complexes.

  20. The conformational stability, solvation and the assignments of the experimental infrared, Raman, (1)H and (13)C NMR spectra of the local anesthetic drug lidocaine.

    Science.gov (United States)

    Badawi, Hassan M; Förner, Wolfgang; Ali, Shaikh A

    2015-05-05

    The structure, vibrational and (1)H and (13)C NMR spectra of the local anesthetic drug lidocaine were investigated by the B3LYP/6-311G(∗∗) calculations. The molecule was predicted to have the non-planar cis (NCCN∼0°) structures being about 2-6kcal/mol lower in energy than the corresponding trans (NCCN∼180°) forms. The calculated NCCN (9.6°) and CNCC (-132.2°) torsional angles were in a good qualitative agreement with the reported X-ray angles (3.1 and 13.0°, -102.67 and -77.9°, respectively, for H-bonded dimers). The Gibbs energy of solution of lidocaine in formamide, water, dimethylsulfoxide, acetonitrile, methanol, ethanol and chloroform solutions was estimated at the B3LYP level. The predicted affinity of lidocaine toward the alcohols, acetonitrile and chloroform solutions was in excellent agreement with the reported experimental solubility of the drug in organic solvents. The analysis of the observed vibrational spectra is consistent with the presence of lidocaine in only one conformation at room temperature. The (1)H and (13)C NMR spectra of lidocaine were interpreted by experimental and DFT calculated chemical shifts of the drug. The RMSD between experimental and theoretical (1)H and (13)C chemical shifts for lidocaine is 0.47 and 8.26ppm, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. The conformational stability, solvation and the assignments of the experimental infrared, Raman, 1H and 13C NMR spectra of the local anesthetic drug lidocaine

    Science.gov (United States)

    Badawi, Hassan M.; Förner, Wolfgang; Ali, Shaikh A.

    2015-05-01

    The structure, vibrational and 1H and 13C NMR spectra of the local anesthetic drug lidocaine were investigated by the B3LYP/6-311G∗∗ calculations. The molecule was predicted to have the non-planar cis (NCCN ∼ 0°) structures being about 2-6 kcal/mol lower in energy than the corresponding trans (NCCN ∼ 180°) forms. The calculated NCCN (9.6°) and CNCC (-132.2°) torsional angles were in a good qualitative agreement with the reported X-ray angles (3.1 and 13.0°, -102.67 and -77.9°, respectively, for H-bonded dimers). The Gibbs energy of solution of lidocaine in formamide, water, dimethylsulfoxide, acetonitrile, methanol, ethanol and chloroform solutions was estimated at the B3LYP level. The predicted affinity of lidocaine toward the alcohols, acetonitrile and chloroform solutions was in excellent agreement with the reported experimental solubility of the drug in organic solvents. The analysis of the observed vibrational spectra is consistent with the presence of lidocaine in only one conformation at room temperature. The 1H and 13C NMR spectra of lidocaine were interpreted by experimental and DFT calculated chemical shifts of the drug. The RMSD between experimental and theoretical 1H and 13C chemical shifts for lidocaine is 0.47 and 8.26 ppm, respectively.

  2. Aberrant EEG functional connectivity and EEG power spectra in resting state post-traumatic stress disorder: a sLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Farina, Benedetto; Quintiliani, Maria Isabella; Onofri, Antonio; Castelli Gattinara, Paola; Lepore, Marta; Gnoni, Valentina; Mazzucchi, Edoardo; Contardi, Anna; Della Marca, Giacomo

    2014-10-01

    The aim of the present study was to explore the modifications of EEG power spectra and EEG connectivity of resting state (RS) condition in patients with post-traumatic stress disorder (PTSD). Seventeen patients and seventeen healthy subjects matched for age and gender were enrolled. EEG was recorded during 5min of RS. EEG analysis was conducted by means of the standardized Low Resolution Electric Tomography software (sLORETA). In power spectra analysis PTSD patients showed a widespread increase of theta activity (4.5-7.5Hz) in parietal lobes (Brodmann Area, BA 7, 4, 5, 40) and in frontal lobes (BA 6). In the connectivity analysis PTSD patients also showed increase of alpha connectivity (8-12.5Hz) between the cortical areas explored by Pz-P4 electrode. Our results could reflect the alteration of memory systems and emotional processing consistently altered in PTSD patients. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Experimental results using active control of traveling wave power flow

    Science.gov (United States)

    Miller, David W.; Hall, Steven R.

    1991-01-01

    Active structural control experiments conducted on a 24-ft pinned-free beam derived feedback compensators on the basis of a traveling-wave approach. A compensator is thus obtained which eliminates resonant behavior by absorbing all impinging power. A causal solution is derived for this noncausal compensator which mimics its behavior in a given frequency range, using the Wiener-Hopf. This optimal Wiener-Hopf compensator's structure-damping performance is found to exceed any obtainable by means of rate feedback. Performance limitations encompassed the discovery of frequencies above which the sensor and actuator were no longer dual and an inadvertent coupling of the control hardware to unmodeled structure torsion modes.

  4. Coupling and scattering power exchange between phonon modes observed in surface-enhanced Raman spectra of single-wall carbon nanotubes on silver colloidal clusters

    Science.gov (United States)

    Kneipp, K.; Perelman, L. T.; Kneipp, H.; Backman, V.; Jorio, A.; Dresselhaus, G.; Dresselhaus, M. S.

    2001-05-01

    In the surface-enhanced Raman spectra of single-wall carbon nanotubes on silver colloidal clusters, at high excitation laser intensities, we observed with increasing laser excitation intensity, an exchange in the scattering power between two phonon modes that constitute the 1590 cm-1 feature of the G band. We explain this effect in terms of phonon-phonon coupling, which occurs for the extremely strong Raman effect in intense optical fields in the ``hot'' areas of silver clusters.

  5. Experimentation with a reverse osmosis plant powered by renewable energies

    Energy Technology Data Exchange (ETDEWEB)

    Segura, L.; Gomez, A. [Las Palmas de Gran Canaria Univ., Las Palmas (Spain). Dept. of Process Engineering; Nuez, I. [Las Palmas de Gran Canaria Univ., Las Palmas (Spain). Dept. of Electronic and Automatic Engineering

    2006-07-01

    This paper described a set of tests conducted in a reverse osmosis plant powered by renewable energy sources. Variations on feed flow, reject flow, recovery and power consumption were investigated. The plant has a production of over 115 m{sup 3} per day. During the experiments, the plant was required to operate at variable loading conditions. An energy recovery system was then developed to operate effectively with the observed variable load conditions. The system was incorporated within the reject flow system and was comprised of a Pelton turbine matched to the axis of an asynchronous energy generator. The system was designed to avoid making changes to the actual hydraulic circuit of the plant. Recovery system failures did not necessitate plant stoppages during the testing period. Simulations conducted to assess the energy system showed that optimal performance of the plant was between 16 and 18 kW with a working pressure of between 57 to 67 bars. Results also suggested that installing the system in the evacuation brine line would maximize the use of kinetic energy. It was concluded that energy recovery systems are ideal for use in seawater installations where functioning pressure levels are high. 14 refs., 1 tab., 5 figs.

  6. Monte Carlo simulation of the experimental pulse height spectra produced in diamond detectors by quasi-mono-energetic neutrons

    Science.gov (United States)

    Milocco, A.; Pillon, M.; Angelone, M.; Plompen, A.; Krása, A.; Trkov, A.

    2013-08-01

    This work was carried out in view of the possible use of diamond detectors as high resolution neutron spectrometers for the ITER project. An MCNP5(X) based computational tool has been developed to simulate the fast neutron response of diamond detectors. The source neutrons are generated by a source routine, developed earlier, that includes deuteron beam energy loss, angular straggling, and two-body relativistic kinematics. The diamond detector routine calculates a pulse height spectrum that is built up by elastic and inelastic scattering, (n,a), (n,p), and (n,d) reaction channels. A combination of nuclear data from ENDF/B-VII.0, TENDL-2010, and ENSDF is used. The simulated spectra are compared with measured spectra. It is shown that the simulation tool allows an interpretation of most of the characteristic features in the spectrum. This is an important step towards the use of diamond detectors for spectral analysis and fluence measurements. © 2001 Elsevier Science.

  7. Power spectra and auto correlation analysis of hyperfine-induced long period oscillations in the tunneling current of coupled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Harack, B.; Leary, A.; Coish, W. A.; Hilke, M. [Department of Physics, McGill University, Ernest Rutherford Building, 3600 rue University, Montreal, Quebec H3A 2T8 (Canada); Yu, G.; Gupta, J. A. [National Research Council of Canada, M50, Montreal Road, Ottawa, Ontario K1A 0R6 (Canada); Payette, C.; Austing, D. G. [Department of Physics, McGill University, Ernest Rutherford Building, 3600 rue University, Montreal, Quebec H3A 2T8, Canada and National Research Council of Canada, M50, Montreal Road, Ottawa, Ontario K1A 0R6 (Canada)

    2013-12-04

    We outline power spectra and auto correlation analysis performed on temporal oscillations in the tunneling current of coupled vertical quantum dots. The current is monitored for ∼2325 s blocks as the magnetic field is stepped through a high bias feature displaying hysteresis and switching: hallmarks of the hyperfine interaction. Quasi-periodic oscillations of ∼2 pA amplitude and of ∼100 s period are observed in the current inside the hysteretic feature. Compared to the baseline current outside the hysteretic feature the power spectral density is enhanced by up to three orders of magnitude and the auto correlation displays clear long lived oscillations about zero.

  8. Experimental determination of bone cortex holding power of orthopedic screw

    Directory of Open Access Journals (Sweden)

    Bolliger Neto Raul

    1999-01-01

    Full Text Available Cylindrical specimens of bone measuring 15 mm in diameter were obtained from the lateral cortical layer of 10 pairs of femurs and tibias. A central hole 3.2 mm in diameter was drilled in each specimen. The hole was tapped, and a 4.5 mm cortical bone screw was inserted from the outer surface. The montage was submitted to push-out testing up to a complete strip of the bone threads. The cortical thickness and rupture load were measured, and the shear stress was calculated. The results were grouped according to the bone segment from which the specimen was obtained. The results showed that bone cortex screw holding power is dependent on the bone site. Additionally, the diaphyseal cortical bone tissue is both quantitatively and qualitatively more resistant to screw extraction than the metaphyseal tissue.

  9. An Effective Experimental Optimization Method for Wireless Power Transfer System Design Using Frequency Domain Measurement

    Directory of Open Access Journals (Sweden)

    Sangyeong Jeong

    2017-10-01

    Full Text Available This paper proposes an experimental optimization method for a wireless power transfer (WPT system. The power transfer characteristics of a WPT system with arbitrary loads and various types of coupling and compensation networks can be extracted by frequency domain measurements. The various performance parameters of the WPT system, such as input real/imaginary/apparent power, power factor, efficiency, output power and voltage gain, can be accurately extracted in a frequency domain by a single passive measurement. Subsequently, the design parameters can be efficiently tuned by separating the overall design steps into two parts. The extracted performance parameters of the WPT system were validated with time-domain experiments.

  10. Effect of twine diameter on fishing power of experimental gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    The relative fishing powers of experimental gill nets were estimated for shorthorn sculpin (Myoxocephalus scorpius), Greenland cod (Gadus ogac), and Atlantic cod (Gadus morhua). The results suggested that fishing power was negatively correlated to the ratio between twine diameter and mesh size...

  11. Power-Based Setpoint Control : Experimental Results on a Planar Manipulator

    NARCIS (Netherlands)

    Dirksz, D. A.; Scherpen, J. M. A.

    In the last years the power-based modeling framework, developed in the sixties to model nonlinear electrical RLC networks, has been extended for modeling and control of a larger class of physical systems. In this brief we apply power-based integral control to a planar manipulator experimental setup.

  12. Carbon Nanotubes' Effect on Mitochondrial Oxygen Flux Dynamics: Polarography Experimental Study and Machine Learning Models using Star Graph Trace Invariants of Raman Spectra.

    Science.gov (United States)

    González-Durruthy, Michael; Monserrat, Jose M; Rasulev, Bakhtiyor; Casañola-Martín, Gerardo M; Barreiro Sorrivas, José María; Paraíso-Medina, Sergio; Maojo, Víctor; González-Díaz, Humberto; Pazos, Alejandro; Munteanu, Cristian R

    2017-11-11

    This study presents the impact of carbon nanotubes (CNTs) on mitochondrial oxygen mass flux (Jm) under three experimental conditions. New experimental results and a new methodology are reported for the first time and they are based on CNT Raman spectra star graph transform (spectral moments) and perturbation theory. The experimental measures of Jm showed that no tested CNT family can inhibit the oxygen consumption profiles of mitochondria. The best model for the prediction of Jm for other CNTs was provided by random forest using eight features, obtaining test R-squared (R²) of 0.863 and test root-mean-square error (RMSE) of 0.0461. The results demonstrate the capability of encoding CNT information into spectral moments of the Raman star graphs (SG) transform with a potential applicability as predictive tools in nanotechnology and material risk assessments.

  13. Experimental measurement of structural power flow on an aircraft fuselage

    Science.gov (United States)

    Cuschieri, J. M.

    1991-01-01

    An experimental technique is used to measure structural intensity through an aircraft fuselage with an excitation load applied near one of the wing attachment locations. The fuselage is a relatively large structure, requiring a large number of measurement locations to analyze the whole of the structure. For the measurement of structural intensity, multiple point measurements are necessary at every location of interest. A tradeoff is therefore required between the number of measurement transducers, the mounting of these transducers, and the accuracy of the measurements. Using four transducers mounted on a bakelite platform, structural intensity vectors are measured at locations distributed throughout the fuselage. To minimize the errors associated with using the four transducer technique, the measurement locations are selected to be away from bulkheads and stiffeners. Furthermore, to eliminate phase errors between the four transducer measurements, two sets of data are collected for each position, with the orientation of the platform with the four transducers rotated by 180 degrees and an average taken between the two sets of data. The results of these measurements together with a discussion of the suitability of the approach for measuring structural intensity on a real structure are presented.

  14. Experimental studies on power transformer model winding provided with MOVs

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2017-05-01

    Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.

  15. Theoretical and experimental study of micro air vehicle powered by RF signal at 10 GHz

    OpenAIRE

    Tsolis, George

    2003-01-01

    Approved for public release, distribution is unlimited The concept of using electromagnetic energy in the form of microwaves for transferring power from one point to another through free space is very old. However, the idea for powering micro air vehicles using microwaves is less than a decade old. This thesis presents a theoretical and experimental study of powering a micro air vehicle, using electromagnetic energy at the frequency of 10 GHz. Two micro air vehicle prototypes were designed...

  16. Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

    Directory of Open Access Journals (Sweden)

    Saber Ismail

    2018-01-01

    Full Text Available Spectral lines of low-temperature nitrogen photoionized plasma were investigated. The photoionized plasma was created in the result of irradiation N2 gas using laser plasma EUV radiation pulses. The source was based on a 10J/10ns Nd:YAG (λ = 1064 nm laser system and a gas puff target. The EUV radiation pulses were collected and focused using a grazing incidence multifoil EUV collector. The emission spectra were measured in the ultraviolet and visible (UV/Vis range. It was found that the plasma emission lines in the lower region of the UV range are relativley weak. Nonetheless, a part of the spectra contains strong molecular band in the 300 - 430 nm originated from second positive and first negative systems band transitions of nitrogen. These molecular band transitions were identified using a code for study the diatomic molecules, LIFBASE. The vibrational band of Δv = 0 and ±1 transitions were significantly populated than of that with Δv = ±2 and 3 transitions. A comparison of the calculated and measured spectrum is presented. With an assumption of a local thermodynamic equilibrium (LTE, the vibrational temperature was determined from the integrated band intensities with the help of the Boltzmann plot method and compared to the temperature predicted by SPECAIR and LIFBASE simulations. A summary of the results and the variations in the vibrational temperatures was discussed.

  17. Monte Carlo simulation of the experimental pulse height spectra produced in diamond detectors by quasi-mono-energetic neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Milocco, A., E-mail: alberto.milocco@ijs.si [Jožef Stefan Institute, Reactor Physics Department, Jamova 39, 1000 Ljubljana (Slovenia); Pillon, M.; Angelone, M. [Associazione EURATOM-ENEA sulla Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Rome) (Italy); Plompen, A.; Krása, A. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Trkov, A. [Jožef Stefan Institute, Reactor Physics Department, Jamova 39, 1000 Ljubljana (Slovenia)

    2013-08-21

    This work was carried out in view of the possible use of diamond detectors as high resolution neutron spectrometers for the ITER project. An MCNP5(X) based computational tool has been developed to simulate the fast neutron response of diamond detectors. The source neutrons are generated by a source routine, developed earlier, that includes deuteron beam energy loss, angular straggling, and two-body relativistic kinematics. The diamond detector routine calculates a pulse height spectrum that is built up by elastic and inelastic scattering, (n,a), (n,p), and (n,d) reaction channels. A combination of nuclear data from ENDF/B-VII.0, TENDL-2010, and ENSDF is used. The simulated spectra are compared with measured spectra. It is shown that the simulation tool allows an interpretation of most of the characteristic features in the spectrum. This is an important step towards the use of diamond detectors for spectral analysis and fluence measurements. {sup ©} 2001 Elsevier Science. All rights reserved.

  18. Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

    Science.gov (United States)

    Saber, Ismail; Bartnik, Andrzej; Skrzeczanowski, Wojciech; Wachulak, Przemyslaw; Jarocki, Roman; Fiedorowicz, Henryk; Limpouch, Jiri

    2018-01-01

    Spectral lines of low-temperature nitrogen photoionized plasma were investigated. The photoionized plasma was created in the result of irradiation N2 gas using laser plasma EUV radiation pulses. The source was based on a 10J/10ns Nd:YAG (λ = 1064 nm) laser system and a gas puff target. The EUV radiation pulses were collected and focused using a grazing incidence multifoil EUV collector. The emission spectra were measured in the ultraviolet and visible (UV/Vis) range. It was found that the plasma emission lines in the lower region of the UV range are relativley weak. Nonetheless, a part of the spectra contains strong molecular band in the 300 - 430 nm originated from second positive and first negative systems band transitions of nitrogen. These molecular band transitions were identified using a code for study the diatomic molecules, LIFBASE. The vibrational band of Δv = 0 and ±1 transitions were significantly populated than of that with Δv = ±2 and 3 transitions. A comparison of the calculated and measured spectrum is presented. With an assumption of a local thermodynamic equilibrium (LTE), the vibrational temperature was determined from the integrated band intensities with the help of the Boltzmann plot method and compared to the temperature predicted by SPECAIR and LIFBASE simulations. A summary of the results and the variations in the vibrational temperatures was discussed.

  19. EXPERIMENTAL VERIFICATION OF COMPUTER MODEL OF COOLING SYSTEM FOR POWERFUL SEMI- CONDUCTOR DEVICE

    Directory of Open Access Journals (Sweden)

    I. A. Khorunzhii

    2007-01-01

    Full Text Available A cooling system for powerful semi-conductor device (power -1 kW consisting of a pin-type radiator and a body is considered in the paper. Cooling is carried out by forced convection of a coolant. Calculated values of temperatures on the radiator surface and experimentally measured values of temperatures in the same surface points have been compared in the paper. It has been shown that the difference between calculated and experimentally measured temperatures does not exceed 0,1-0,2 °C and it is comparable with experimental error value. The given results confirm correctness of a computer model.

  20. Experimental Study on a Passive Fuel Cell/Battery Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Yong-Song Chen

    2013-12-01

    Full Text Available A laboratory-scale passive hybrid power system for transportation applications is constructed and tested in this study. The hybrid power system consists of a fuel cell stack connected with a diode, a lithium-ion battery pack connected with a DC/DC power converter and another diode. The power converter is employed to regulate the output voltage of the battery pack. The dynamic responses of current and voltage of the stack to the start-up and acceleration of the load are experimentally investigated at two different selected output voltages of the DC/DC converter in the battery line. The power sharing of each power source and efficiency are also analyzed and discussed. Experimental results show that the battery can compensate for the shortage of supplied power for the load demand during the start-up and acceleration. The lowest operating voltage of the fuel cell stack is limited by the regulated output voltage of the DC/DC converter. The major power loss in the hybrid power system is attributed to the diodes. The power train efficiency can be improved by lowering the ratio of forward voltage drop of the diode to the operating voltage of the fuel cell stack.

  1. Experimental study of the X-ray spectra optimization for computed radiography mammography systems; Investigacao experimental da otimizacao do espectro de raios X em sistemas de mamografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Tomal, Alessandra, E-mail: atomal@ifi.unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Instituto de Fisica Gleb Wataghin; Cunha, Diego M. [Universidade Federal de Uberlandia (UFU), Uberlandia, MG (Brazil). Instituto de Fisica; Nogueira, Maria S. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Gaspar, Fabio [Vigilancia Sanitaria, Campinas, SP (Brazil); Poletti, Martin E. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Departamento de Fisica

    2013-12-15

    Digital mammography is replacing screen-film mammography due to several advantages of digital receptors. The use of Computed Radiography (CR) mammography systems has been considered an alternative to achieve digital images with a low cost. Besides, the optimization of the X-ray spectrum, characterized by the anode/filter combination and tube potential, is an important step in order to improve the image quality with the lower dose to the breast. In this work, we investigated the optimal X-ray spectra using a figure of merit for two mammography equipment: Senographe DMR (General Electric Medical Systems) and Mammomat 3000 Nova (Siemens), both using an image plate Kodak EHR-M2 (Kodak DirectView). A PMMA phantom, simulating breast with thicknesses of 5 cm, was used. The anode/filter combinations evaluated were: Mo/Mo, Mo/Rh, Rh/Rh and Rh/Al for the Senographe system, and Mo/Mo, Mo/Rh, W/Rh for the Mammomat system, for all the intervals of tube potential range from 24 to 35 kVp. Results demonstrate that the higher values of FOM were achieved with the Rh/Rh at 29 kVp and Rh/Al at 26 kVp for the Senographe system, and for the W/Rh at 28 kVp in the Mammomat one. The reduction in the dose associated with the optimum spectra was 13 and 26% for the Senographe and Mammomat systems, respectively. Finally, our results suggest that anode/filter combinations of more energetic spectra than the standard Mo/Mo combination are recommended for thicker breast, in order to reduce the breast dose levels. (author)

  2. Investigating the features in differential absorbance spectra of NOM associated with metal ion binding: A comparison of experimental data and TD-DFT calculations for model compounds.

    Science.gov (United States)

    Yan, Mingquan; Han, Xuze; Zhang, Chenyang

    2017-11-01

    In this study, seven model compounds containing typical functional groups (phenolic and carboxylic groups) present in nature organic matter (NOM) were used to ascertain the nature of the characteristic bands in differential absorbance spectra (DAS) of NOM that are induced by metal ion binding. Some similarities were found between the DAS of the examined model compounds, caffeic acid, ferulic acid, sinapic acid, terephthalic acid, isophthalic acid, esculetin and myricetin and those of NOM. The binding of Cu(II) with carboxylic group might produce two peaks, A1 and A2, while the binding of Cu(II) with phenolic group might produce all four Gaussian peaks, from A1 to A4 displayed in the DAS of NOM. The UV-visible spectra predicted using time-dependent density functional theory (TD-DFT)-based methods met well with the experimental DAS of model compounds at different stages of Cu(II) binding. It demonstrates that the features in absorbance spectra are chiefly caused by HOMO (Highest Occupied Molecular Orbital) - LUMO (Lowest Unoccupied Molecular Orbital) transitions in the molecule and that the appearance of peaks in DAS reflects the changes of the molecular orbitals around reactive functional groups in a molecule before and after metal ion binding. The basis of the DAS features of NOM that are induced by metal ion binding could be identified primarily by the frontier molecular orbital theory. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Analysis and Experimental Evaluation of Power Line Transmission Parameters for Power Line Communication

    Science.gov (United States)

    Mlynek, P.; Misurec, J.; Koutny, M.; Fujdiak, R.; Jedlicka, T.

    2015-04-01

    The article describes a way of evaluating the power line channel frequency response and input impedance by means of the linear time-invariant (LTI) power line generator. Two possible methods are introduced for the calculation of primary parameters: the first method depends on the physical realization and physical dimension of the cable, and the second method is derived from the data provided by typical electrical cable manufacturers. Based on these methods, a comparison of transfer functions was made. This is followed by measurement evaluation and numerical verification on a simple topology

  4. Management of Power Quality Issues in Low Voltage Networks using Electric Vehicles: Experimental Validation

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Knezovic, Katarina; Marinelli, Mattia

    2017-01-01

    the existing and future power quality problems. One of the main aspects of the power quality relates to voltage quality. The aim of this work is to experimentally analyse whether series-produced EVs, adhering to contemporary standard and without relying on any V2G capability, can mitigate line voltage drops...... in improving the power quality of a highly unbalanced grid......As Electric Vehicles (EVs) are becoming more wide spread, their high power consumption presents challenges for the residential low voltage networks, especially when connected to long feeders with unevenly distributed loads. However, if intelligently integrated, EVs can also partially solve...

  5. Experimental and theoretical studies of CO2 spectra for planetary atmosphere modelling: region 600-9650 cm(-1) and pressures up to 60 atm.

    Science.gov (United States)

    Filippov, Nikolai N; Asfin, Ruslan E; Sinyakova, Tatiana N; Grigoriev, Ivan M; Petrova, Tatiana M; Solodov, Alexandr M; Solodov, Alexandr A; Buldyreva, Jeanna V

    2013-09-07

    Extensive experimental studies of room-temperature carbon dioxide absorption coefficients are reported for a wide range of wavenumbers and pressures requested in atmospheric spectra modelling. The quality of measurements is optimised by the use of two complementary setups with long- and short-path optical cells for low and high gas densities, respectively. The recorded spectra provide a representative picture of band-shape evolutions from gaseous to nearly liquid phases of CO2 and enable a theoretical analysis of line-mixing effects. Various kinds of vibrational bands (Σ←Σ, Π←Σ as well as Π←Π transitions) are modelled using a specific, non-Markovian in the general case, approach of Energy-Corrected Sudden type which is based on the symmetric relaxation matrix and, in contrast to the standard ECS model used for infrared absorption calculations, ensures automatically the fundamental relations of detailed balance and double-sided sum rules. Moreover, this method properly accounts for the vibrational angular momenta of the initial and final molecular states and allows including Coriolis resonances via the usual Herman-Wallis factors in the dipole transition moments. With a set of ECS parameters previously obtained for isotropic and anisotropic Raman spectra modelling, completely neglected imaginary part of the relaxation operator and a simple change in the tensorial rank to get the dipole absorption case in the working formulae, the computed spectra reproduce quite correctly the vibrotational band shapes up to 20 amagat without any additional parameter. An empirical correction factor tentatively introduced to account globally for the Coriolis effects on the relaxation matrix leads to better matches with high-density band shapes but its role merits further studies with an accurately modelled imaginary part of the relaxation matrix.

  6. The breaks and the hidden components in the power-law spectra of synchrotron radiation of the self-consistent current structures

    Energy Technology Data Exchange (ETDEWEB)

    Kocharovsky, V. V., E-mail: vkochar@physics.tamu.edu [Institute of Applied Physics, Russian Academy of Science, 46 Ulyanov Street, Nizhny Novgorod 603950 (Russian Federation); Department of Physics and Astronomy, Texas A& M University, College Station, Texas 77843-4242 (United States); Kocharovsky, VI. V.; Tarasov, S. V. [Institute of Applied Physics, Russian Academy of Science, 46 Ulyanov Street, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, Nizhny Novgorod 603950 (Russian Federation); Martyanov, V. Ju. [ZAO “Intel” A/O, 30 Turgeneva Street, Nizhny Novgorod 603024 (Russian Federation)

    2015-08-15

    Widespread use of a broken-power-law description of the spectra of synchrotron emission of various plasma objects requires an analysis of origin and a proper interpretation of spectral components. We show that, for a self-consistent magnetic configuration in a collisionless plasma, these components may be angle-dependent according to an anisotropic particle momentum distribution and may have no counterparts in a particle energy distribution. That has never been studied analytically and is in contrast to a usual model of synchrotron radiation, assuming an external magnetic field and a particle ensemble with isotropic momentum distribution. We demonstrate that for the wide intervals of observation angle the power-law spectra and, in particular, the positions and number of spectral breaks may be essentially different for the cases of the self-consistent and not-self-consistent magnetic fields in current structures responsible for the synchrotron radiation of the ensembles of relativistic particles with the multi-power-law energy distributions.

  7. Analysis and experimental evaluation of shunt active power filter for power quality improvement based on predictive direct power control.

    Science.gov (United States)

    Aissa, Oualid; Moulahoum, Samir; Colak, Ilhami; Babes, Badreddine; Kabache, Nadir

    2017-10-12

    This paper discusses the use of the concept of classical and predictive direct power control for shunt active power filter function. These strategies are used to improve the active power filter performance by compensation of the reactive power and the elimination of the harmonic currents drawn by non-linear loads. A theoretical analysis followed by a simulation using MATLAB/Simulink software for the studied techniques has been established. Moreover, two test benches have been carried out using the dSPACE card 1104 for the classic and predictive DPC control to evaluate the studied methods in real time. Obtained results are presented and compared in this paper to confirm the superiority of the predictive technique. To overcome the pollution problems caused by the consumption of fossil fuels, renewable energies are the alternatives recommended to ensure green energy. In the same context, the tested predictive filter can easily be supplied by a renewable energy source that will give its impact to enhance the power quality.

  8. Absorption spectra measurements of the x-ray radiation heated sio{sub 2} aerogel plasma in 'dog-bone' targets irradiated by high power laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Dong, Q-L; Wang, S-J; Li, Y-T; Zhang, J [Laboratory of Optical Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Wei, H-G; Shi, J-R; Zhao, G [National Astronomical Observatories of China, Chinese Academy of Sciences. Beijing 100012 (China); Zhang, J-Y; Wen, T-S; Zhang, W-H; Hu, X; Liu, S-Y; Ding, Y-K; Zhang, L; Tang, Y-J; Zhang, B-H; Zheng, Z-J [Research Center for Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Nishimura, H; Fujioka, S [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871 (Japan)], E-mail: yizhang@aphy.iphy.ac.cn, E-mail: ytli@aphy.iphy.ac.cn, E-mail: jzhang@aphy.iphy.ac.cn (and others)

    2008-05-01

    We studied the opacity effect of the SiO{sub 2} aerogel plasma heated by x-ray radiation produced by high power laser pulses irradiating the inner surface of golden 'dog-bone' targets. The PET crystal spectrometer was used to measure the absorption spectra of the plasmas in the range from 6.4 A to 7.4 A, among which the line emissions involving the K shell of Si ions from He-like to neutral atom were located. The experimental results were analyzed with Detailed-Level-Accounting method. As the plasma temperature increased, the characteristic lines of highly ionized ions gradually dominated the absorption spectrum.

  9. Experimental and Numerical Investigation of Termination Impedance Effects in Wireless Power Transfer via Metamaterial

    Directory of Open Access Journals (Sweden)

    Giovanni Puccetti

    2015-03-01

    Full Text Available This paper presents an investigation of the transmitted power in a wireless power transfer system that employs a metamaterial. Metamaterials are a good means to transfer power wirelessly, as they are composed of multiple inductively-coupled resonators. The system can be designed and matched simply through magneto-inductive wave theory, particularly when the receiver inductor is located at the end of the metamaterial line. However, the power distribution changes significantly in terms of transmitted power, efficiency and frequency if the receiver inductor slides along the line. In this paper, the power distribution and transfer efficiency are analysed, studying the effects of a termination impedance in the last cell of the metamaterial and improving the system performance for the resonant frequency and for any position of the receiver inductor. Furthermore, a numerical characterisation is presented in order to support experimental tests and to predict the performance of a metamaterial composed of spiral inductor cells with very good accuracy.

  10. Analysis, design, and experimental evaluation of power calculation in digital droop-controlled parallel microgrid inverters

    DEFF Research Database (Denmark)

    Gao, Ming-zhi; Chen, Min; Jin, Cheng

    2013-01-01

    the digital implementation of a droop method, and analyzes the influence of power calculation on droop method performance. According to the analysis, the performance of droop control in a digital control system is limited by the accuracy and speed of the power calculation method. We propose an improved power...... distributed generators in a parallel operation. Frequency and voltage droop is a well-established control method for improving power sharing performance. In this method, the active and reactive power calculations are used to adjust the frequency and amplitude of the output voltage. This paper describes...... calculation method based on p-q theory to improve the performance of the droop control method, and we compare our new method with two traditional power calculation methods. Finally, simulation results and experimental results from a three single-phase 1-kW-inverter system are presented, which validate...

  11. The 0.3-30 Kev Spectra Of Powerful Starburst Galaxies: Nustar And Chandra Observations Of Ngc 3256 And Ngc 3310

    DEFF Research Database (Denmark)

    Lehmer, B. D.; Tyler, J. B.; Hornschemeier, A. E.

    2015-01-01

    We present nearly simultaneous Chandra and NuSTAR observations of two actively star-forming galaxies within 50 Mpc: NGC 3256 and NGC 3310. Both galaxies are significantly detected by both Chandra and NuSTAR, which together provide the first-ever spectra of these two galaxies spanning 0.3-30 ke...... with equivalent measurements for nearby star-forming galaxies M83 and NGC 253, we analyze the star formation rate (SFR) normalized spectra of these starburst galaxies. The spectra of all four galaxies show sharply declining power-law slopes at energies above 3-6 keV primarily due to ULX populations. Our......-Eddington accreting ULXs that have been studied individually in a targeted NuSTAR ULX program. We also find that NGC 3310 exhibits a factor of ≈3-10 elevation of X-ray emission over the other star-forming galaxies due to a corresponding overabundance of ULXs. We argue that the excess of ULXs in NGC 3310 is most...

  12. Influence of excitation power density on temperature dependencies of NaYF4: Yb, Er nanoparticles luminescence spectra

    Science.gov (United States)

    Ustalkov, Sergey O.; Kozlova, Ekaterina A.; Savenko, Olga A.; Mohammed, Ammar H. M.; Kochubey, Vyacheslav I.; Skaptsov, Alexander A.

    2017-03-01

    Upconversion nanoparticles are good candidates for nanothermometry. The wavelength of the excitation and luminescence lie in optical window. The influence of the excitation power density on the luminescence temperature dependences is studded. Ratio of luminescence intensities linearly depends on temperature.

  13. Hartley transforms and narrow bessel bandpass filters produce similar power spectra of multiple frequency oscillators and all-night EEG.

    Science.gov (United States)

    Trachsel, L

    1993-09-01

    Frequency specific power obtained from time and frequency domain analyses are explored in simulated signals and all-night electroencephalogram (EEG). Signals were subjected to a fast Hartley transformation (FHT) and to digital sixth-order Bessel bandpass filters (BDF) of the infinite impulse response type. Numeric values of FHT, BDF and, if suited, authentic frequency specific power were subjected to a Pearson correlation. Frequency bins at 1.6-2.4 Hz (delta), 4.75-5.9 Hz (theta), 9.3-11.5 Hz (alpha), 12.5-14.9 Hz (sigma) and 16.6-19.5 Hz (beta) were investigated. When compared with true power of single frequency oscillators (256-sample windows), frequency specific power of the FHT correlated functionally (1.0) and BDF correlated highly (0.85, delta; 0.99, other bins). For analyses of "white noise", a multiple frequency oscillator and all-night EEG, four rectangular window sizes were applied (256, 512, 1,024 or 2,048 samples). The FHT power correlated better with authentic frequency specific power of "white noise" (256-sample windows) (0.61-0.98) than BDF power (0.67-0.89). With 512-sample windows of "white noise", the estimate of both the FHT (0.69-0.99) and BDF (0.71-0.93) improved. Direct comparison between FHT and BDF frequency specific power obtained from "white noise" or all-night EEG revealed a high degree of compliance between methods for all frequency bins (up to 0.99). For delta, the accord was relatively low for the 256-sample window (EEG, 0.68; "white noise", 0.72), but increased with lengthening window size (2,048-sample: 0.97; 0.99). Averaging of multiple EEG 256-sample windows also increased the agreement between methods.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Methods and benefits of experimental seismic evaluation of nuclear power plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    This study reviews experimental techniques, instrumentation requirements, safety considerations, and benefits of performing vibration tests on nuclear power plant containments and internal components. The emphasis is on testing to improve seismic structural models. Techniques for identification of resonant frequencies, damping, and mode shapes, are discussed. The benefits of testing with regard to increased damping and more accurate computer models are oulined. A test plan, schedule and budget are presented for a typical PWR nuclear power plant.

  15. Slow wave sleep in the chronically fatigued: Power spectra distribution patterns in chronic fatigue syndrome and primary insomnia.

    Science.gov (United States)

    Neu, Daniel; Mairesse, Olivier; Verbanck, Paul; Le Bon, Olivier

    2015-10-01

    To investigate slow wave sleep (SWS) spectral power proportions in distinct clinical conditions sharing non-restorative sleep and fatigue complaints without excessive daytime sleepiness (EDS), namely the chronic fatigue syndrome (CFS) and primary insomnia (PI). Impaired sleep homeostasis has been suspected in both CFS and PI. We compared perceived sleep quality, fatigue and sleepiness symptom-intensities, polysomnography (PSG) and SWS spectral power distributions of drug-free CFS and PI patients without comorbid sleep or mental disorders, with a good sleeper control group. Higher fatigue without EDS and impaired perceived sleep quality were confirmed in both patient groups. PSG mainly differed in sleep fragmentation and SWS durations. Spectral analysis revealed a similar decrease in central ultra slow power (0.3-0.79Hz) proportion during SWS for both CFS and PI and an increase in frontal power proportions of faster frequencies during SWS in PI only. The latter was correlated to affective symptoms whereas lower central ultra slow power proportions were related to fatigue severity and sleep quality impairment. In combination with normal (PI) or even increased SWS durations (CFS), we found consistent evidence for lower proportions of slow oscillations during SWS in PI and CFS. Observing normal or increased SWS durations but lower proportions of ultra slow power, our findings suggest a possible quantitative compensation of altered homeostatic regulation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Experimental and theoretical study of the CD spectra and conformational properties of axially chiral 2,2'-, 3,3'-, and 4,4'-biphenol ethers.

    Science.gov (United States)

    Mori, Tadashi; Inoue, Yoshihisa; Grimme, Stefan

    2007-05-24

    New chiral biphenol ethers (Biph22, Biph33, and Biph44), carrying (R)-methylpropyloxy groups at 2,2'-, 3,3'-, and 4,4'-positions of biphenyl, were prepared. The introduced peripheral chiral groups in these biphenol ethers induce an (averaged) axial chirality to give predominant aR- or aS-rotamers. The chiroptical properties of these axially chiral biphenol ethers in polar and nonpolar solvents were determined experimentally and were compared with the corresponding theoretical values to determine their conformational behavior in solution. Geometry optimization at the DFT-D/TZV2P level and subsequent time-dependent density functional theory (TD-DFT) at the BH-LYP/TZV2P level treatments to obtain rotatory strengths revealed that 6 out of 18 conformers (aR-Tg-, aR-Tg+, aR-G+t, aS-Tg-, aS-Tg+, and aS-G+t) are crucial to reproduce the experimental circular dichroism (CD) spectra and optical rotations. Although biphenyl molecules are in conformational equilibrium with varying interplanar angles in solution, our static approach to the prediction of the experimental CD spectra is simply based on pairs of thermally populated, local-minimum structures, that is, the dynamic behavior of the systems or the vibrational wave functions are not considered. The relative energies computed at the SCS-MP2/TZVPP level in the gas phase or in acetonitrile solution using the conductor-like screening model (COSMO) were found to be accurate enough to calculate the thermal population of the relevant conformers. Although most of the CD signals mutually cancel out each other between a pair of aR- and aS-rotamers, the remaining Cotton effects due to a small preference for a single rotamer produce characteristic CD spectra. In general (and somewhat unexpectedly), the delicate cancellation effects in the CD spectra are accurately described by the theoretical approach, and the simulated CD spectra are in excellent agreement with the experimental ones though observed rotatory strengths being always

  17. Theoretical and Experimental Study of Phonon Spectra of Bulk and Nano-Sized MoS2 Layer Crystals

    Science.gov (United States)

    Yaremko, Anatoliy Mikhailovich; Yukhymchuk, Volodymyr Oleksandrovych; Romanyuk, Yuriy Anatolijovych; Baran, Jan; Placidi, Marcel

    2017-01-01

    Theoretical analysis of Raman scattering spectra (RS) for single-crystal MoS2 sample and atomically thin MoS2 sample consisting from one to few layers was performed in order to explain the change of MoS2 vibrations at transition from a monoatomic layer to a bulk crystal. Experiments have shown that changes of frequencies of the most intensive bands arising from the in-plane, {E}_{2 g}^1 , and out-of-plane, A 1 g , vibrations, as a function of number n of layers looks differently. Thus, the frequency of ω( A 1 g ) is increasing with growth of n, whereas the frequency of ω ({E}_{2 g}^1) is decreasing. Such a change of the ω ({E}_{2 g}^1) frequency was explained as the effect of "strong increase of the dielectric tensor when going from single layer to the bulk" sample. In the present work, we show that the reason of different dependences of frequencies can be related to both the van der Waals (vdW) interlayer interaction and the anharmonic interaction of noted fundamental vibrations with the corresponding combination tones (CT) of layer that manifests itself due to Fermi resonance in the layer. Overjumping of these phonon pairs ( s, s ') owing to interlayer interaction, tilde{V}({}_{s, s', q}^p) , to other layers at growth of number n, results in the change of frequencies for each interacting pair of A 1 g or {E}_{2 g}^1 symmetry. The alteration of pair frequencies depends on the ratio of constants tilde{V}({}_{s, s', q}^p) describing the interaction of studied states s and s '.

  18. Experimental investigation of the hyperfine spectra of Pr I - lines: discovery of new fine structure levels with low angular momentum

    Science.gov (United States)

    Shamim, K.; Siddiqui, I.; Windholz, L.

    2011-10-01

    We present 39 odd and 15 even parity newly discovered fine structure levels of Pr I with low angular momentum: J = 1/2, 3/2 and 5/2. Spectral lines in the range 4200 Å to 7500 Å were experimentally investigated using laser induced fluorescence spectroscopy in a hollow cathode discharge lamp. The levels were discovered by analysis of the recorded hyperfine patterns of the investigated transitions. With the help of these levels, 119 spectral lines were classified directly by laser excitation and 127 lines were classified as fluorescence lines.

  19. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  20. Circular dichroism and optical absorption spectra of mononuclear and trinuclear chiral Cu(II) amino-alcohol coordinated compounds: A combined theoretical and experimental study

    Science.gov (United States)

    Valencia, Israel; Ávila-Torres, Yenny; Barba-Behrens, Norah; Garzón, Ignacio L.

    2015-04-01

    Studies on the physicochemical properties of biomimetic compounds of multicopper oxidases are fundamental to understand their reaction mechanisms and catalytic behavior. In this work, electronic, optical, and chiroptical properties of copper(II) complexes with amino-alcohol chiral ligands are theoretically studied by means of time-dependent density functional theory. The calculated absorption and circular dichroism spectra are compared with experimental measurements of these spectra for an uncoordinated pseudoephedrine derivative, as well as for the corresponding mononuclear and trinuclear copper(II)-coordinated complexes. This comparison is useful to gain insights into their electronic structure, optical absorption and optical activity. The optical absorption and circular dichroism bands of the pseudoephedrine derivative are located in the UV-region. They are mainly due to transitions originated from n to π anti-bonding orbitals of the alcohol and amino groups, as well as from π bonding to π anti-bonding orbitals of carboxyl and phenyl groups. In the case of the mononuclear and trinuclear compounds, additional signals in the visible spectral region are present. In both systems, the origin of these bands is due to charge transfer from ligand to metal and d-d transitions.

  1. Minimisation of instrumental noise in the acquisition of FT-NIR spectra of bread wheat using experimental design and signal processing techniques.

    Science.gov (United States)

    Foca, G; Ferrari, C; Sinelli, N; Mariotti, M; Lucisano, M; Caramanico, R; Ulrici, A

    2011-02-01

    Spectral resolution (R) and number of repeated scans (S) have a significant effect on the S/N ratio of Fourier transform-near infrared (FT-NIR) spectra, but the optimal values of these two parameters have to be determined empirically for a specific problem, considering separately both the nature of the analysed matrix and the specific instrumental setup. To achieve this aim, the instrumental noise of replicated FT-NIR spectra of wheat samples was modelled as a function of R and S by means of the Doehlert design. The noise amounts in correspondence to different experimental conditions were estimated by analysing the variance signals derived from replicate measurements with two different signal processing tools, Savitzky-Golay (SG) filtering and fast wavelet transform (FWT), in order to separate the "pure" instrumental noise from other variability sources, which are essentially connected to sample inhomogeneity. Results confirmed that R and S values leading to minimum instrumental noise can vary considerably depending on the type of analysed food matrix and on the different instrumental setups, and helped in the selection of the optimal measuring conditions for the subsequent acquisition of a wide spectral dataset.

  2. A thermoelectric power generating heat exchanger: Part I – Experimental realization

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Sarhadi, Ali; Pryds, Nini

    2016-01-01

    An experimental realization of a heat exchanger with commercial thermoelectric generators (TEGs) is presented. The power producing capabilities as a function of flow rate and temperature span are characterized for two different commercial heat transfer fluids and for three different thermal...

  3. Experimental Evaluation of Electric Power Grid Visualization Tools in the EIOC

    Energy Technology Data Exchange (ETDEWEB)

    Greitzer, Frank L.; Dauenhauer, Peter M.; Wierks, Tamara G.; Podmore, Robin; Dalton, Angela C.

    2009-12-01

    The present study follows an initial human factors evaluation of four electric power grid visualization tools and reports on an empirical evaluation of two of the four tools: Graphical Contingency Analysis, and Phasor State Estimator. The evaluation was conducted within specific experimental studies designed to measure the impact on decision making performance.

  4. Line-Shape Code Comparison through Modeling and Fitting of Experimental Spectra of the C ii 723-nm Line Emitted by the Ablation Cloud of a Carbon Pellet

    Directory of Open Access Journals (Sweden)

    Mohammed Koubiti

    2014-07-01

    Full Text Available Various codes of line-shape modeling are compared to each other through the profile of the C ii 723-nm line for typical plasma conditions encountered in the ablation clouds of carbon pellets, injected in magnetic fusion devices. Calculations were performed for a single electron density of 1017 cm−3 and two plasma temperatures (T = 2 and 4 eV. Ion and electron temperatures were assumed to be equal (Te = Ti = T. The magnetic field, B, was set equal to either to zero or 4 T. Comparisons between the line-shape modeling codes and two experimental spectra of the C ii 723-nm line, measured perpendicularly to the B-field in the Large Helical Device (LHD using linear polarizers, are also discussed.

  5. A combined experimental and theoretical studies on FT-IR, FT-Raman and UV-vis spectra of 2-chloro-3-quinolinecarboxaldehyde.

    Science.gov (United States)

    Prasad, M V S; Udaya Sri, N; Veeraiah, V

    2015-09-05

    In the present study, the FT-IR and FT-Raman spectra of 2-chloro-3-quinolinecarboxaldehyde (2Cl3QC) have been recorded in the region 4000-400 and 3500-50 cm(-1), respectively. The fundamental modes of vibrational frequencies of 2Cl3QC are assigned. Theoretical information on the optimized geometry, harmonic vibrational frequencies, infrared and Raman intensities were obtained by means of density functional theory (DFT) gradient calculations with complete relaxation in the potential energy surface using 6-31G(d,p) basis set. The vibrational frequencies which were determined experimentally from the spectral data are compared with those obtained theoretically from DFT calculations. A close agreement was achieved between the observed and calculated frequencies by refinement of the scale factors. The infrared and Raman spectra were also predicted from the calculated intensities. Thermodynamic properties like entropy, heat capacity, zero point energy, have been calculated for the molecule. The predicted first hyperpolarizability also shows that the molecule might have a reasonably good non-linear optical (NLO) behavior. The calculated HOMO-LUMO energy gap reveals that charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interactions, charge delocalization have been analyzed using natural bond orbitals (NBO) analysis. The results show that charge in electron density (ED) in the π(∗) antibonding orbitals and E((2)) energies confirms the occurrence of ICT (intra-molecular charge transfer) within the molecule. UV-visible spectrum of the title molecule has also been calculated using TD-DFT/CAM-B3LYP/6-31G(d,p) method. The calculated energy and oscillator strength almost exactly reproduces reported experimental data. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Modifications of EEG Power Spectra in Mesial Temporal Lobe during n-back tasks of increasing difficulty. A sLORETA study.

    Directory of Open Access Journals (Sweden)

    Claudio eImperatori

    2013-04-01

    Full Text Available The n-back task is widely used to investigate the neural basis of Working Memory (WM processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs 3-back.Fourteen healthy subjects were enrolled (7 men and 7 women, mean age 31.21±7.05 years, range: 23-48. EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized LOw Resolution brain Electric Tomography (sLORETA software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher’s z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz; theta (4.5–7.5 Hz; alpha (8–12.5 Hz; beta (13–30 Hz; gamma (30.5–100 Hz. Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA 28 in the left posterior entorhinal cortex (T = 3.112; p<0.05 and in the BA 35 in the left peririnhal cortex in the parahippocampal gyrus (T = 2.876; p<0.05. No significant differences were observed in the right hemisphere and in the alpha, theta, beta and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

  7. Modifications of EEG power spectra in mesial temporal lobe during n-back tasks of increasing difficulty. A sLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Farina, Benedetto; Brunetti, Riccardo; Gnoni, Valentina; Testani, Elisa; Quintiliani, Maria I; Del Gatto, Claudia; Indraccolo, Allegra; Contardi, Anna; Speranza, Anna M; Della Marca, Giacomo

    2013-01-01

    The n-back task is widely used to investigate the neural basis of Working Memory (WM) processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs. 3-back). Fourteen healthy subjects were enrolled (seven men and seven women, mean age 31.21 ± 7.05 years, range: 23-48). EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized Low Resolution brain Electric Tomography (sLORETA) software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher's z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta (13-30 Hz); gamma (30.5-100 Hz). Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA) 28 in the left posterior entorhinal cortex (T = 3.112; p < 0.05) and in the BA 35 in the left perirhinal cortex in the parahippocampal gyrus (T = 2.876; p < 0.05). No significant differences were observed in the right hemisphere and in the alpha, theta, beta, and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

  8. Digital simulation of two-dimensional random fields with arbitrary power spectra and non-Gaussian probability distribution functions

    DEFF Research Database (Denmark)

    Yura, Harold; Hanson, Steen Grüner

    2012-01-01

    Methods for simulation of two-dimensional signals with arbitrary power spectral densities and signal amplitude probability density functions are disclosed. The method relies on initially transforming a white noise sample set of random Gaussian distributed numbers into a corresponding set with the......Methods for simulation of two-dimensional signals with arbitrary power spectral densities and signal amplitude probability density functions are disclosed. The method relies on initially transforming a white noise sample set of random Gaussian distributed numbers into a corresponding set...... with the desired spectral distribution, after which this colored Gaussian probability distribution is transformed via an inverse transform into the desired probability distribution. In most cases the method provides satisfactory results and can thus be considered an engineering approach. Several illustrative...

  9. THE 0.3–30 keV SPECTRA OF POWERFUL STARBURST GALAXIES: NuSTAR AND CHANDRA OBSERVATIONS OF NGC 3256 AND NGC 3310

    Energy Technology Data Exchange (ETDEWEB)

    Lehmer, B. D.; Wik, D. R.; Yukita, M. [The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Tyler, J. B.; Hornschemeier, A. E.; Ptak, A.; Zhang, W. W. [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Antoniou, V.; Zezas, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Boggs, S.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Harrison, F. A. [Caltech Division of Physics, Mathematics and Astronomy, Pasadena (United States); Maccarone, T. J. [Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2015-06-10

    We present nearly simultaneous Chandra and NuSTAR observations of two actively star-forming galaxies within 50 Mpc: NGC 3256 and NGC 3310. Both galaxies are significantly detected by both Chandra and NuSTAR, which together provide the first-ever spectra of these two galaxies spanning 0.3–30 keV. The X-ray emission from both galaxies is spatially resolved by Chandra; we find that hot gas dominates the E < 1–3 keV emission while ultraluminous X-ray sources (ULXs) provide majority contributions to the emission at E > 1–3 keV. The NuSTAR galaxy-wide spectra of both galaxies follow steep power-law distributions with Γ ≈ 2.6 at E > 5–7 keV. Using new and archival Chandra data, we search for signatures of heavily obscured or low luminosity active galactic nuclei (AGNs). We find that both NGC 3256 and NGC 3310 have X-ray detected sources coincident with nuclear regions; however, the steep NuSTAR spectra of both galaxies restricts these sources to be either low luminosity AGNs (L{sub 2−10} {sub keV}/L{sub Edd} ≲ 10{sup −5}) or non-AGNs in nature (e.g., ULXs or crowded X-ray sources that reach L{sub 2−10} {sub keV} ∼ 10{sup 40} erg s{sup −1} cannot be ruled out). Combining our constraints on the 0.3–30 keV spectra of NGC 3256 and NGC 3310 with equivalent measurements for nearby star-forming galaxies M83 and NGC 253, we analyze the star formation rate (SFR) normalized spectra of these starburst galaxies. The spectra of all four galaxies show sharply declining power-law slopes at energies above 3–6 keV primarily due to ULX populations. Our observations therefore constrain the average spectral shape of galaxy-wide populations of luminous accreting binaries (i.e., ULXs). Interestingly, despite a completely different galaxy sample selection, emphasizing here a range of SFRs and stellar masses, these properties are similar to those of super-Eddington accreting ULXs that have been studied individually in a targeted NuSTAR ULX program. We also find that

  10. An experimental study of a PEM fuel cell power train for urban bus application

    Science.gov (United States)

    Corbo, P.; Migliardini, F.; Veneri, O.

    An experimental study was carried out on a fuel cell propulsion system for minibus application with the aim to investigate the main issues of energy management within the system in dynamic conditions. The fuel cell system (FCS), based on a 20 kW PEM stack, was integrated into the power train comprising DC-DC converter, Pb batteries as energy storage systems and asynchronous electric drive of 30 kW. As reference vehicle a minibus for public transportation in historical centres was adopted. A preliminary experimental analysis was conducted on the FCS connected to a resistive load through a DC-DC converter, in order to verify the stack dynamic performance varying its power acceleration from 0.5 kW s -1 to about 4 kW s -1. The experiments on the power train were conducted on a test bench able to simulate the vehicle parameters and road characteristics on specific driving cycles, in particular the European R40 cycle was adopted as reference. The "soft hybrid" configuration, which permitted the utilization of a minimum size energy storage system and implied the use of FCS mainly in dynamic operation, was compared with the "hard hybrid" solution, characterized by FCS operation at limited power in stationary conditions. Different control strategies of power flows between fuel cells, electric energy storage system and electric drive were adopted in order to verify the two above hybrid approaches during the vehicle mission, in terms of efficiencies of individual components and of the overall power train. The FCS was able to support the dynamic requirements typical of R40 cycle, but an increase of air flow rate during the fastest acceleration phases was necessary, with only a slight reduction of FCS efficiency. The FCS efficiency resulted comprised between 45 and 48%, while the overall power train efficiency reached 30% in conditions of constant stack power during the driving cycle.

  11. Experimental investigation of fan-folded piezoelectric energy harvesters for powering pacemakers

    Science.gov (United States)

    Ansari, M. H.; Karami, M. Amin

    2017-06-01

    This paper studies the fabrication and testing of a magnet free piezoelectric energy harvester (EH) for powering biomedical devices and sensors inside the body. The design for the EH is a fan-folded structure consisting of bimorph piezoelectric beams folding on top of each other. An actual size experimental prototype is fabricated to verify the developed analytical models. The model is verified by matching the analytical results of the tip acceleration frequency response functions (FRF) and voltage FRF with the experimental results. The generated electricity is measured when the EH is excited by the heartbeat. A closed loop shaker system is utilized to reproduce the heartbeat vibrations. Achieving low fundamental natural frequency is a key factor to generate sufficient energy for pacemakers using heartbeat vibrations. It is shown that the natural frequency of the small-scale device is less than 20 {{Hz}} due to its unique fan-folded design. The experimental results show that the small-scale EH generates sufficient power for state of the art pacemakers. The 1 cm3 EH with 18.4 {{g}}{{r}} tip mass generates more than 16 μ {{W}} of power from a normal heartbeat waveform. The robustness of the device to the heart rate is also studied by measuring the relation between the power output and the heart rate.

  12. Research on the attribution evaluating methods of dynamic effects of various parameter uncertainties on the in-structure floor response spectra of nuclear power plant

    Science.gov (United States)

    Li, Jianbo; Lin, Gao; Liu, Jun; Li, Zhiyuan

    2017-01-01

    Consideration of the dynamic effects of the site and structural parameter uncertainty is required by the standards for nuclear power plants (NPPs) in most countries. The anti-seismic standards provide two basic methods to analyze parameter uncertainty. Directly manually dealing with the calculated floor response spectra (FRS) values of deterministic approaches is the first method. The second method is to perform probability statistical analysis of the FRS results on the basis of the Monte Carlo method. The two methods can only reflect the overall effects of the uncertain parameters, and the results cannot be screened for a certain parameter's influence and contribution. In this study, based on the dynamic analyses of the floor response spectra of NPPs, a comprehensive index of the assessed impact for various uncertain parameters is presented and recommended, including the correlation coefficient, the regression slope coefficient and Tornado swing. To compensate for the lack of guidance in the NPP seismic standards, the proposed method can effectively be used to evaluate the contributions of various parameters from the aspects of sensitivity, acuity and statistical swing correlations. Finally, examples are provided to verify the set of indicators from systematic and intuitive perspectives, such as the uncertainty of the impact of the structure parameters and the contribution to the FRS of NPPs. The index is sensitive to different types of parameters, which provides a new technique for evaluating the anti-seismic parameters required for NPPs.

  13. Management of waste from the International Thermonuclear Experimental Reactor and from future fusion power plants

    Energy Technology Data Exchange (ETDEWEB)

    Broden, K. [Association EURATOM, Nykoeping (Sweden); Lindberg, M. [Association EURATOM, Nykoeping (Sweden); Nisan, S. [The NET Team, Garching (Germany); Rocco, P. [European Commission, Institute for Advanced Materials, Joint Research Centre, Ispra (Vatican City State, Holy See) (Italy); Zucchetti, M. [Energetics Department, Polytechnic of Turin, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Taylor, N. [Association EURATOM-UKAEA, UKAEA Fusion, Culham, Abingdon, Oxfordshire, OX14 3DB (United Kingdom); Forty, C. [Association EURATOM-UKAEA, UKAEA Fusion, Culham, Abingdon, Oxfordshire, OX14 3DB (United Kingdom)

    1997-04-01

    An important inherent advantage of fusion would be the total absence of high-level radioactive spent fuel as produced in fission reactors. Fusion will, however, produce activated material containing both activation products and tritium. Part of the material may also contain chemically toxic substances. This paper describes methods that could be used to manage these materials and also methods to reduce or entirely eliminate the waste quantities. The results are based on studies for the International Thermonuclear Experimental Reactor and also for future fusion power station designs currently under investigation within the European programme on the safety and environmental assessment of fusion power, long-term. (orig.)

  14. Experimental Validation of BDI Agents for Distributed Control of Electric Power Grids

    DEFF Research Database (Denmark)

    Issicaba, Diego; Rosa, Mauro A.; Prostejovsky, Alexander Maria

    2017-01-01

    , respectively. Belief-desire-intention reasoning is achieved through JASON’s engine while artifacts monitor and control grid devices using dedicated JAVA objects. Experiments have been conducted in SYSLAB, a testbed for distributed power system control and distributed solutions, located at the Risø campus...... of the Technical University of Denmark. Experimental results show the feasibility of applying belief-desire-intention reasoning to WoC control using a test case where tie-line power flow setpoints must be followed...

  15. ESTIMATION OF ROUTINE DISCHARGE OF RADIONUCLIDES ON POWER REACTOR EXPERIMENTAL RDE

    OpenAIRE

    Udiyani, P.M; Sri Kuntjoro

    2017-01-01

    Experimental power reactor (RDE) which is planned to be constructed by BATAN is a kind of High Temperature Gas Cooled Reactor (HTGR) with 10 MWth power. HTGR is a helium gas-cooled reactor with TRISO-coated fuel that is able to confine fission products remained in the core. Although the fission products released into the environment are very small, in order to comply the regulations the study about environmental radiation on normal or routine operation condition need to be performed. Estimati...

  16. High-power diode lasers at 1178  nm with high beam quality and narrow spectra.

    Science.gov (United States)

    Paschke, K; Bugge, F; Blume, G; Feise, D; Erbert, G

    2015-01-01

    High-power distributed Bragg reflector tapered diode lasers (DBR-TPLs) at 1180 nm were developed based on highly strained InGaAs quantum wells. The lasers emit a nearly diffraction-limited beam with more than two watts with a narrow spectral width. These features are believed to make this type of diode laser a key component for the manufacturing of miniaturized laser modules in the yellow and orange spectral range by second-harmonic generation to cover a spectral region currently not accessible with direct emitting diode lasers. Future applications might be the laser-cooling of sodium, high-resolution glucose-content measurements, as well as spectroscopy on rare earth elements.

  17. Power density and temperature effects on the photoluminescence spectra of InAlAs/GaAlAs quantum dots

    Science.gov (United States)

    Ben Daly, A.; Riahi, H.; Bernardot, F.; Barisien, T.; Galopin, E.; Lemaître, A.; Maaref, M. A.; Testelin, C.

    2017-04-01

    Photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurement techniques are used to characterize the size and the density of In1-xAlxAs/Ga0.67Al0.33As quantum dots (QDs) for different QD aluminium compositions. The integrated photoluminescence intensity (IPL) depends on an excitation light power, decreases with increasing the aluminium proportion emphasizing the QDs surface density decreasing. In TRPL experiments, the influence of QD lateral coupling is evidence in high QD density sample, the radiative lifetime increases with increasing temperatures for sample with a low aluminium proportion, instead, the observed radiative lifetime keep constant for samples with a high aluminium proportions in agreement with the QD zero-dimensional confinement.

  18. Conceptual studies of toroidal field magnets for the tokamak experimental power reactor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Buncher, B.R.; Chi, J.W.H.; Fernandez, R.

    1976-10-26

    This report documents the principal results of a Conceptual Design Study for the Superconducting Toroidal Field System for a Tokamak Experimental Power Reactor. Two concepts are described for peak operating fields at the windings of 8 tesla, and 12 tesla, respectively. The design and manufacturing considerations are treated in sufficient detail that cost and schedule estimates could be developed. Major uncertainties in the design are identified and their potential impact discussed, along with recommendations for the necessary research and development programs to minimize these uncertainties. The minimum dimensions of a sub-size test coil for experimental qualification of the full size design are developed and a test program is recommended.

  19. A randomized controlled trial into the effects of neurofeedback, methylphenidate, and physical activity on EEG power spectra in children with ADHD.

    Science.gov (United States)

    Janssen, Tieme W P; Bink, Marleen; Geladé, Katleen; van Mourik, Rosa; Maras, Athanasios; Oosterlaan, Jaap

    2016-05-01

    The clinical and neurophysiological effects of neurofeedback (NF) as treatment for children with ADHD are still unclear. This randomized controlled trial (RCT) examined electroencephalogram (EEG) power spectra before and after NF compared to methylphenidate (MPH) treatment and physical activity (PA) - as semi-active control group - during resting and active (effortful) task conditions to determine whether NF can induce sustained alterations in brain function. Using a multicentre three-way parallel group RCT design, 112 children with a DSM-IV diagnosis of ADHD, aged between 7 and 13 years, were initially included. NF training consisted of 30 sessions of theta/beta training at Cz over a 10-week period. PA training was a semi-active control group, matched in frequency and duration. Methylphenidate was titrated using a double-blind placebo controlled procedure in 6 weeks, followed by a stable dose for 4 weeks. EEG power spectra measures during eyes open (EO), eyes closed (EC) and task (effortful) conditions were available for 81 children at pre- and postintervention (n = 29 NF, n = 25 MPH, n = 27 PA). Train Your Brain? Exercise and Neurofeedback Intervention for ADHD, https://clinicaltrials.gov/show/;NCT01363544, Ref. No. NCT01363544. Both NF and MPH resulted in comparable reductions in theta power from pre- to postintervention during the EO condition compared to PA (ηp (2)  = .08 and .12). For NF, greater reductions in theta were related to greater reductions in ADHD symptoms. During the task condition, only MPH showed reductions in theta and alpha power compared to PA (ηp (2)  = .10 and .12). This study provides evidence for specific neurophysiological effects after theta/beta NF and MPH treatment in children with ADHD. However, for NF these effects did not generalize to an active task condition, potentially explaining reduced behavioural effects of NF in the classroom. © 2016 Association for Child and Adolescent Mental Health.

  20. Fisher's sons' effect in sexual selection: absent, intermittent or just low experimental power?

    Science.gov (United States)

    Sharma, M D; Wilson, A J; Hosken, D J

    2016-12-01

    The Fisherian sexual selection paradigm has been called the null model of sexual selection. At its heart is the expectation of a genetic correlation (rG ) between female preference and male trait. However, recent meta-analysis has shown estimated correlations are often extremely weak and not statistically significant. We show here that systematic failure of studies to reject the null hypothesis that rG  = 0 is almost certainly due to the low power of most experimental designs used. We provide an easy way to assess experimental power a priori and suggest that current data make it difficult to definitively test a key component of the Fisher effect. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  1. Experimental research of the effects of different shields on power frequency electric field mitigation

    Directory of Open Access Journals (Sweden)

    Nahman Jovan

    2012-01-01

    Full Text Available The paper describes experimental research on the effects of different shields on power frequency electric field mitigation. This research was performed in order to determine those materials that may be used for electric field mitigation in cases where the reference level is exceeded. Using measured results, the value of the shielding factor has been calculated for all tested shields and the most efficient shields were determined.

  2. Power Management Optimization of an Experimental Fuel Cell/Battery/Supercapacitor Hybrid System

    Directory of Open Access Journals (Sweden)

    Farouk Odeim

    2015-06-01

    Full Text Available In this paper, an experimental fuel cell/battery/supercapacitor hybrid system is investigated in terms of modeling and power management design and optimization. The power management strategy is designed based on the role that should be played by each component of the hybrid power source. The supercapacitor is responsible for the peak power demands. The battery assists the supercapacitor in fulfilling the transient power demand by controlling its state-of-energy, whereas the fuel cell system, with its slow dynamics, controls the state-of-charge of the battery. The parameters of the power management strategy are optimized by a genetic algorithm and Pareto front analysis in a framework of multi-objective optimization, taking into account the hydrogen consumption, the battery loading and the acceleration performance. The optimization results are validated on a test bench composed of a fuel cell system (1.2 kW, 26 V, lithium polymer battery (30 Ah, 37 V, and a supercapacitor (167 F, 48 V.

  3. An experimental comparison between several active composite actuators for power generation

    Science.gov (United States)

    Sodano, Henry A.; Lloyd, Justin; Inman, Daniel J.

    2006-10-01

    The use of piezoelectric materials for power harvesting has attracted significant interest over the past few years. The majority of research on this subject has sought to quantify the amount of energy generated in power harvesting applications, or to develop methods of improving the amount of energy generated. Usually, a monolithic piezoelectric material with a traditional electrode pattern and poled through its thickness is used for power harvesting. However, in recent years several companies and research institutions have begun to develop and market a broad range of piezoelectric composite sensor/actuator packages, each conceived for specific operational advantages and characteristics. Commonly, these devices are employed in control and vibration suppression applications, and their potential for use in power-harvesting systems remains largely unknown. Two frequently implemented design techniques for improving the performance of such actuators are the use of interdigitated electrodes and piezofibers. This paper seeks to experimentally quantify the differences in performance in power-harvesting applications between several of these new actuators and to identify the reasons for their relative performance characteristics. A special focus on the structural and compositional differences between each actuator is incorporated in the discussion of the effectiveness of each actuator as a power-harvesting device.

  4. Experimental Study of the Power Profile Airfoil Equipped with Plasma Flow Control

    Science.gov (United States)

    Daniel, Libin; Jacob, Jamey

    2013-11-01

    This presentation discusses results from an experimental study of the power profile airfoil at low Reynolds number. The power profile airfoil was developed by AMO Smith and consists of a blunt trailing edge shape with two wall jets near the trailing edge. The replacement of streamlining with properly designed blowing is used to prevent flow separation and additionally offers potential applications as a powered high-lift system, propulsive system, or low inertia control device. The 2D wind-tunnel model consists of the 22.5% thick power profile airfoil equipped with a movable trailing edge plug to direct flow along the trailing edge streamline. Compressed air was passed into the model via a plenum with flow conditioning devices to create pressure backdrop to allow uniform blowing at the trailing edge. The effects of varying jet momentum coefficient and trailing edge positioning on the aerodynamic characteristics are observed with both wake surveys and PIV. The impact of plasma synthetic jet actuators (PSJA) placed along the trailing edge of the power profile airfoil is also discussed. PSJA operation is compared to the baseline power profile airfoil both alone and working with the blowing to provide additional control authority.

  5. Experimental study of a fuel cell power train for road transport application

    Science.gov (United States)

    Corbo, P.; Corcione, F. E.; Migliardini, F.; Veneri, O.

    The development of fuel cell electric vehicles requires the on-board integration of fuel cell systems and electric energy storage devices, with an appropriate energy management system. The optimization of performance and efficiency needs an experimental analysis of the power train, which has to be effected in both stationary and transient conditions (including standard driving cycles). In this paper experimental results concerning the performance of a fuel cell power train are reported and discussed. In particular characterization results for a small sized fuel cell system (FCS), based on a 2.5 kW PEM stack, alone and coupled to an electric propulsion chain of 3.7 kW are presented and discussed. The control unit of the FCS allowed the main stack operative parameters (stoichiometric ratio, hydrogen and air pressure, temperature) to be varied and regulated in order to obtain optimized polarization and efficiency curves. Experimental runs effected on the power train during standard driving cycles have allowed the performance and efficiency of the individual components (fuel cell stack and auxiliaries, dc-dc converter, traction batteries, electric engine) to be evaluated, evidencing the role of output current and voltage of the dc-dc converter in directing the energy flows within the propulsion system.

  6. Experimental Study of a Low-Temperature Power Generation System in an Organic Rankine Cycle

    DEFF Research Database (Denmark)

    Mu, Yongchao; Zhang, Yufeng; Deng, Na

    2015-01-01

    as the engine of the power generator. The style of the preheater was a shell and tube heat exchanger, which could provide a long path for the working fluid. A flooded heat exchanger with a high heat transfer coefficient was taken as the evaporator. R134a was used as working fluid for the Rankine cycle......This paper presents a new power generation system under the principle of organic Rankine cycle which can generate power with a low-temperature heat source. A prototype was built to investigate the proposed system. In the prototype, an air screw compressor was converted into an expander and used...... in the system. This study compared and analyzed the experimental performance of the prototype at different heat source temperatures. The results show that the preheater and flooded evaporator was used for sensible heating and latent heating of the working fluid, respectively, as expected. When the temperature...

  7. Experimental Investigation of the Power Generation Performance of Floating-Point Absorber Wave Energy Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Yu, Y.; Epler, J.; Previsic, M.

    2012-04-01

    The extraction of energy from ocean waves has gained interest in recent years. The floating-point absorber (FPA) is one of the most promising devices among a wide variety of wave energy conversion technologies. Early theoretical studies mainly focused on understanding the hydrodynamics of the system and on predicting the maximum power that could be extracted by a heaving body. These studies evolve from the investigation of floating-body interactions in offshore engineering and naval architecture disciplines. To our best knowledge, no systematic study has been reported about the investigation of the power generation performance of an FPA with a close-to-commercial design. A series of experimental tests was conducted to investigate the power extraction performance of an FPA system.

  8. A Comparison of Cosmological Parameters Determined from CMB Temperature Power Spectra from the South Pole Telescope and the Planck Satellite

    Science.gov (United States)

    Aylor, K.; Hou, Z.; Knox, L.; Story, K. T.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H.-M.; Chown, R.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W. B.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Keisler, R.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Omori, Y.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2017-11-01

    The Planck cosmic microwave background temperature data are best fit with a ΛCDM model that mildly contradicts constraints from other cosmological probes. The South Pole Telescope (SPT) 2540 {\\deg }2 SPT-SZ survey offers measurements on sub-degree angular scales (multipoles 650≤slant {\\ell }≤slant 2500) with sufficient precision to use as an independent check of the Planck data. Here we build on the recent joint analysis of the SPT-SZ and Planck data in Hou et al. by comparing ΛCDM parameter estimates using the temperature power spectrum from both data sets in the SPT-SZ survey region. We also restrict the multipole range used in parameter fitting to focus on modes measured well by both SPT and Planck, thereby greatly reducing sample variance as a driver of parameter differences and creating a stringent test for systematic errors. We find no evidence of systematic errors from these tests. When we expand the maximum multipole of SPT data used, we see low-significance shifts in the angular scale of the sound horizon and the physical baryon and cold dark matter densities, with a resulting trend to higher Hubble constant. When we compare SPT and Planck data on the SPT-SZ sky patch to Planck full-sky data but keep the multipole range restricted, we find differences in the parameters n s and {A}s{e}-2τ . We perform further checks, investigating instrumental effects and modeling assumptions, and we find no evidence that the effects investigated are responsible for any of the parameter shifts. Taken together, these tests reveal no evidence for systematic errors in SPT or Planck data in the overlapping sky coverage and multipole range and at most weak evidence for a breakdown of ΛCDM or systematic errors influencing either the Planck data outside the SPT-SZ survey area or the SPT data at {\\ell }> 2000.

  9. Relationship between frequency power spectra and intermittent, large-amplitude bursts in the Alcator C-Mod scrape-off layer

    Science.gov (United States)

    Theodorsen, A.; Garcia, O. E.; Kube, R.; LaBombard, B.; Terry, J. L.

    2017-11-01

    Fluctuations in the boundary region of the Alcator C-Mod tokamak have been analyzed using gas puff imaging data from a set of Ohmically heated plasma density scan experiments. It is found that the relative fluctuation amplitudes are modest and close to normally distributed at the separatrix but become increasingly larger and skewed towards the main chamber wall. The frequency power spectra are nevertheless similar for all radial positions and line-averaged densities. Predictions of a stochastic model, describing the plasma fluctuations as a super-position of uncorrelated pulses, are shown to be in excellent agreement with the measurements. This implies that the pulse duration is the same, while the degree of pulse overlap decreases radially outwards in the scrape-off layer. The universal frequency power spectral density is thus determined by the shape and duration of the large-amplitude bursts associated with blob-like structures. The model also describes the rate of threshold level crossings, for which the exponential tails underline the intermittency of the fluctuations in the far scarpe-off layer.

  10. Quantitative EEG in Children and Adults With Attention Deficit Hyperactivity Disorder: Comparison of Absolute and Relative Power Spectra and Theta/Beta Ratio.

    Science.gov (United States)

    Markovska-Simoska, Silvana; Pop-Jordanova, Nada

    2017-01-01

    In recent decades, resting state electroencephalographic (EEG) measures have been widely used to document underlying neurophysiological dysfunction in attention deficit hyperactivity disorder (ADHD). Although most EEG studies focus on children, there is a growing interest in adults with ADHD too. The aim of this study was to objectively assess and compare the absolute and relative EEG power as well as the theta/beta ratio in children and adults with ADHD. The evaluated sample comprised 30 male children and 30 male adults with ADHD diagnosed according to DSM-IV criteria. They were compared with 30 boys and 30 male adults matched by age. The mean age (±SD) of the children's group was 9 (±2.44) years and the adult group 35.8 (±8.65) years. EEG was recorded during an eyes-open condition. Spectral analysis of absolute (μV2) and relative power (%) was carried out for 4 frequency bands: delta (2-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-21 Hz). The findings obtained for ADHD children are increased absolute power of slow waves (theta and delta), whereas adults exhibited no differences compared with normal subjects. For the relative power spectra there were no differences between the ADHD and control groups. Across groups, the children showed greater relative power than the adults in the delta and theta bands, but for the higher frequency bands (alpha and beta) the adults showed more relative power than children. Only ADHD children showed greater theta/beta ratio compared to the normal group. Classification analysis showed that ADHD children could be differentiated from the control group by the absolute theta values and theta/beta ratio at Cz, but this was not the case with ADHD adults. The question that should be further explored is if these differences are mainly due to maturation processes or if there is a core difference in cortical arousal between ADHD children and adults. © EEG and Clinical Neuroscience Society (ECNS) 2016.

  11. Experimental Evaluation of Supercapacitor-Fuel Cell Hybrid Power Source for HY-IEL Scooter

    Directory of Open Access Journals (Sweden)

    Piotr Bujlo

    2013-01-01

    Full Text Available This paper presents the results of development of a hybrid fuel cell supercapacitor power system for vehicular applications that was developed and investigated at the Energy Sources Research Section of the Wroclaw Division of Electrotechnical Institute (IEL/OW. The hybrid power source consists of a polymer exchange membrane fuel cell (PEMFC stack and an energy-type supercapacitor that supports the system in time of peak power demands. The developed system was installed in the HY-IEL electric scooter. The vehicle was equipped with auxiliary components (e.g., air compressor, hydrogen tank, and electromagnetic valves needed for proper operation of the fuel cell stack, as well as electronic control circuits and a data storage unit that enabled on-line recording of system and vehicle operation parameters. Attention is focused on the system energy flow monitoring. The experimental part includes field test results of a vehicle powered with the fuel cell-supercapacitor system. Values of currents and voltages recorded for the system, as well as the vehicle’s velocity and hydrogen consumption rate, are presented versus time of the experiment. Operation of the hybrid power system is discussed and analysed based on the results of measurements obtained.

  12. Design, simulation, and experimental results of a 110 GHz high-power gyrotron mode converter

    Energy Technology Data Exchange (ETDEWEB)

    Denison, D.R.; Blank, M.; Chu, T.S.; Hogge, J.P.; Kreischer, K.E.; Temkin, R.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center; Harper, B.; Lorbeck, J.A.; Vernon, R.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center]|[Univ. of Wisconsin, Madison, WI (United States)

    1996-12-31

    The authors present the design, computer simulation, and experimental results of a quasi-optical mode converter for use in a 110 GHz high-power gyrotron. The particular gyrotron under test generates a right-handed TE{sub 22.6} circular waveguide mode, and is designed to produce megawatt power levels over pulse durations on the order of 5s. This high power level provides a rigorous constraint on the output-beam shape; namely, that the peaking factor be approximately 2.0. Such a peaking factor corresponds to a nearly flat power distribution across the output window to allow for proper cooling of the window. To that end, the mode converter employs a rippled-wall waveguide mode transformer/beam launcher, and a pair of toroidal focusing mirrors to produce a Gaussian-like beam. Two shaping mirrors follow, and convert the Gaussian beam into a quasi-optical beam with a flat power distribution. The rippled-wall launcher was designed using standard coupled mode theory, and the toroidal mirrors derive from Gaussian beam analysis. The shaping mirrors result from a vector diffraction synthesis procedure developed at UW.

  13. Experimental and DFT Investigations Reveal the Influence of the Outer Coordination Sphere on the Vibrational Spectra of Nickel-Substituted Rubredoxin, a Model Hydrogenase Enzyme.

    Science.gov (United States)

    Slater, Jeffrey W; Marguet, Sean C; Cirino, Sabrina L; Maugeri, Pearson T; Shafaat, Hannah S

    2017-04-03

    Nickel-substituted rubredoxin (NiRd) is a functional enzyme mimic of hydrogenase, highly active for electrocatalytic and solution-phase hydrogen generation. Spectroscopic methods can provide valuable insight into the catalytic mechanism, provided the appropriate technique is used. In this study, we have employed multiwavelength resonance Raman spectroscopy coupled with DFT calculations on an extended active-site model of NiRd to probe the electronic and geometric structures of the resting state of this system. Excellent agreement between experiment and theory is observed, allowing normal mode assignments to be made on the basis of frequency and intensity analyses. Both metal-ligand and ligand-centered vibrational modes are enhanced in the resonance Raman spectra. The latter provide information about the hydrogen bonding network and structural distortions due to perturbations in the secondary coordination sphere. To reproduce the resonance enhancement patterns seen for high-frequency vibrational modes, the secondary coordination sphere must be included in the computational model. The structure and reduction potential of the Ni(III)Rd state have also been investigated both experimentally and computationally. This work begins to establish a foundation for computational resonance Raman spectroscopy to serve in a predictive fashion for investigating catalytic intermediates of NiRd.

  14. Fluctuation dynamics and 1/ f spectra characterizing the acoustic cavitation of liquids

    Science.gov (United States)

    Skokov, V. N.; Reshetnikov, A. V.; Vinogradov, A. V.; Koverda, V. P.

    2007-04-01

    The dynamics of acoustic cavitation in water and glycerin is studied experimentally. The power spectra and distribution functions of fluctuations are determined. In transient regimes, bubble structures in the form of fractal clusters are formed near the ultrasonic radiator. The power spectra have the form 1/ f, and the distribution functions of local fluctuations differ from the Gaussian ones and exhibit the scale invariance property.

  15. Modification of EEG functional connectivity and EEG power spectra in overweight and obese patients with food addiction: An eLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Fabbricatore, Mariantonietta; Innamorati, Marco; Farina, Benedetto; Quintiliani, Maria Isabella; Lamis, Dorian A; Mazzucchi, Edoardo; Contardi, Anna; Vollono, Catello; Della Marca, Giacomo

    2015-12-01

    We evaluated the modifications of electroencephalographic (EEG) power spectra and EEG connectivity in overweight and obese patients with elevated food addiction (FA) symptoms. Fourteen overweight and obese patients (3 men and 11 women) with three or more FA symptoms and fourteen overweight and obese patients (3 men and 11 women) with two or less FA symptoms were included in the study. EEG was recorded during three different conditions: 1) five minutes resting state (RS), 2) five minutes resting state after a single taste of a chocolate milkshake (ML-RS), and 3) five minutes resting state after a single taste of control neutral solution (N-RS). EEG analyses were conducted by means of the exact Low Resolution Electric Tomography software (eLORETA). Significant modification was observed only in the ML-RS condition. Compared to controls, patients with three or more FA symptoms showed an increase of delta power in the right middle frontal gyrus (Brodmann Area [BA] 8) and in the right precentral gyrus (BA 9), and theta power in the right insula (BA 13) and in the right inferior frontal gyrus (BA 47). Furthermore, compared to controls, patients with three or more FA symptoms showed an increase of functional connectivity in fronto-parietal areas in both the theta and alpha band. The increase of functional connectivity was also positively associated with the number of FA symptoms. Taken together, our results show that FA has similar neurophysiological correlates of other forms of substance-related and addictive disorders suggesting similar psychopathological mechanisms.

  16. Experimental determination of the MHD-EMP effects on power distribution transformers

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, B.W.; Barnes, P.R. (Oak Ridge National Lab., TN (United States)); Tesche, F.M. (Tesche (F.M.), Dallas, TX (United States))

    1991-01-01

    It is a well-established fact that geomagnetic storms influence electrical power transmission and distribution systems. Previous cases of such storms in the northern latitudes have resulted in occasional power disruptions, and in some cases, damage to transformers. These effects are caused by a time variation of the earth's magnetic field creating an induced electric field along the surface of the earth. This E-field acts as a voltage source along long power transmission or distribution lines, and if the line is connected to the earth at both ends, a quasi-dc current can flow. This current can cause unwanted saturation in the magnetic cores of transformers in the power system, and this, in turn produces harmonic distortion and transformer heating. This can lead to system upset (shutdown) and possibly transformer burn-out. The detonation of a high altitude nuclear explosion is also known to affect the magnetosphere, producing late-time variations of the earth's magnetic field for several hundreds of seconds. Known as the magnetohydrodynamic electromagnetic pulse (MHD-EMP), or E{sub 3}, this environment is of particular concern to electrical power systems in the event of a nuclear attack. Although the MHD-EMP induced currents can be significantly larger in magnitude, they last for a shorter period of time than do those from a geomagnetic storm. The effect of this environment compounds the adverse effects of the early-time high altitude EMP (HEMP) environment, posing a potentially serious threat to the electrical system. The present paper documents an experimental program designed to better understand the behavior of distribution-class transformers subjected to quasi-dc current excitation. Given the knowledge of the MHD-EMP-induced current flowing in a long power line, and the transformer response characteristics obtained in this program, it will be possible to make more accurate assessments of the behavior of the overall power system to EMP. 7 refs., 5 figs.

  17. Inequality spectra

    Science.gov (United States)

    Eliazar, Iddo

    2017-03-01

    Inequality indices are widely applied in economics and in the social sciences as quantitative measures of the socioeconomic inequality of human societies. The application of inequality indices extends to size-distributions at large, where these indices can be used as general gauges of statistical heterogeneity. Moreover, as inequality indices are plentiful, arrays of such indices facilitate high-detail quantification of statistical heterogeneity. In this paper we elevate from arrays of inequality indices to inequality spectra: continuums of inequality indices that are parameterized by a single control parameter. We present a general methodology of constructing Lorenz-based inequality spectra, apply the general methodology to establish four sets of inequality spectra, investigate the properties of these sets, and show how these sets generalize known inequality gauges such as: the Gini index, the extended Gini index, the Rényi index, and hill curves.

  18. Numerical simulation and experimental research of the integrated high-power LED radiator

    Science.gov (United States)

    Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

    2017-01-01

    The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

  19. Experimental Demonstration of Higher Precision Weak-Value-Based Metrology Using Power Recycling

    Science.gov (United States)

    Wang, Yi-Tao; Tang, Jian-Shun; Hu, Gang; Wang, Jian; Yu, Shang; Zhou, Zong-Quan; Cheng, Ze-Di; Xu, Jin-Shi; Fang, Sen-Zhi; Wu, Qing-Lin; Li, Chuan-Feng; Guo, Guang-Can

    2016-12-01

    The weak-value-based metrology is very promising and has attracted a lot of attention in recent years because of its remarkable ability in signal amplification. However, it is suggested that the upper limit of the precision of this metrology cannot exceed that of classical metrology because of the low sample size caused by the probe loss during postselection. Nevertheless, a recent proposal shows that this probe loss can be reduced by the power-recycling technique, and thus enhance the precision of weak-value-based metrology. Here we experimentally realize the power-recycled interferometric weak-value-based beam-deflection measurement and obtain the amplitude of the detected signal and white noise by discrete Fourier transform. Our results show that the detected signal can be strengthened by power recycling, and the power-recycled weak-value-based signal-to-noise ratio can surpass the upper limit of the classical scheme, corresponding to the shot-noise limit. This work sheds light on higher precision metrology and explores the real advantage of the weak-value-based metrology over classical metrology.

  20. Analysis and experimental results of frequency splitting of underwater wireless power transfer

    Directory of Open Access Journals (Sweden)

    Wangqiang Niu

    2017-06-01

    Full Text Available Underwater wireless power transfer (UWPT is an important technique to power underwater devices while its frequency splitting phenomena are not fully elucidated. In this study, frequency splitting phenomena of a symmetrical planar two-coil wireless power transfer (WPT system resonated at 90 kHz are investigated in seawater and freshwater. A concise frequency splitting analysis of this WPT system in air based on circuit model is given first and then experimental data are reported to show there is little difference between power transfer in air, freshwater and seawater in the range of 40–140 kHz of this WPT system. Consequently, the frequency splitting analysis and observations in air are also applicable in freshwater and seawater. It is found a V-type frequency splitting pattern exists in this WPT system under seawater and freshwater. Frequency shift is observed in this UWPT system in overcoupled region, and no frequency shift is observed in undercoupled region. In undercoupled region, in the low frequency zone of 40–90 kHz the load voltage characteristics in three media are identical; in the high-frequency zone of 90–140 kHz, the load voltage in air is slightly larger than those in freshwater and seawater.

  1. Experimental Results From a 2kW Brayton Power Conversion Unit

    Science.gov (United States)

    Hervol, David; Mason, Lee; Birchenough, Arthur

    2003-01-01

    This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for Nuclear Electric Propulsion (NEP).

  2. Alex Houen. Powers of Possibility: Experimental American Writing since the 1960s.

    Directory of Open Access Journals (Sweden)

    Despoina Feleki

    2012-04-01

    Full Text Available After building a socio-political background on Fredric Jameson’s late capitalist postmodernism, Michel Foucault’s “biopolitics,” Herbert Marcuse’s “automatization” of social life and György Lukács’s “abstract” and “concrete” potentials, Alex Houen investigates in his work Powers of Possibility: Experimental American Writing since the 1960s (2012 the main political and technological events which have had a decisive impact on cultural production since the 60s in the U.S. Since Vietnam War, Col...

  3. Los Alamos experimental capabilities: Ancho Canyon high explosives and pulse power facilities

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C.E.

    1993-01-01

    This document outlines the Ancho Canyon testing facility comprehensive material characterization capabilities. These include the high explosive (HE) firing sites, a full complement of gun facilities, and variety of pulse power capacitor bank systems of various energies. The explosive fabrication capability at Los Alamos allows the design and testing of unique HE experimental assemblies. Depending on the hydrodynamic requirements, these explosive systems can vary widely in cost. Years of experience have enabled the development of a comprehensive set of diagnostics to monitor these experiments.

  4. Los Alamos experimental capabilities: Ancho Canyon high explosives and pulse power facilities

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C.E.

    1993-02-01

    This document outlines the Ancho Canyon testing facility comprehensive material characterization capabilities. These include the high explosive (HE) firing sites, a full complement of gun facilities, and variety of pulse power capacitor bank systems of various energies. The explosive fabrication capability at Los Alamos allows the design and testing of unique HE experimental assemblies. Depending on the hydrodynamic requirements, these explosive systems can vary widely in cost. Years of experience have enabled the development of a comprehensive set of diagnostics to monitor these experiments.

  5. Predictive Power of Different Types of Experimental Restraints in Small Molecule Docking: A Review.

    Science.gov (United States)

    Fu, Darwin Y; Meiler, Jens

    2018-01-18

    Incorporating experimental restraints is a powerful method of increasing accuracy in computational protein small molecule docking simulations. Different algorithms integrate distinct forms of biochemical data during the docking and/or scoring stages. These so-called hybrid methods make use of receptor-based information such as nuclear magnetic resonance (NMR) restraints or small molecule-based information such as structure-activity relationships (SARs). A third class of methods directly interrogates contacts between the protein receptor and the small molecule. This work reviews the current state of using such restraints in docking simulations, evaluates their feasibility across broad systems, and identifies potential areas of algorithm development.

  6. Estimates of power generated from synchrotron radiation in the HL-LHC experimental insertion regions

    CERN Document Server

    Rossi, Adriana; CERN. Geneva. ATS Department

    2017-01-01

    The power generated in single magnets of the HL-LHC experimental regions is estimated for collision optics HLLHCV1.2 β*=15 cm Round and HLLHCV1.2 Flat. Note that the layout used for the computations presented here is that before the recent change of baseline. These values should serve as input to Monte-Carlo codes (i.e., PHOTON [ ], Synrad [ ] or others), able to calculate the heat load distribution along the machine and in particular the Long Straight Sections (LSS).

  7. Design of high-pressure direct contact heater for promising power supply units: Experimental substantiation

    Science.gov (United States)

    Somova, E. V.; Shvarts, A. L.; Turkin, A. V.

    2016-11-01

    The results of experimental studies of superheated steam condensation on feed water jets in a highpressure, direct-contact heat exchanger are presented. Direct contact feed water heater (DCFWH) can be used in a dual-flow diagram of a steam-power unit with ultrasupercritical steam parameters (35 MPa, 700/720°C). The direct contact feed water heater is included in the flow diagram of the II circuit in a promising power unit; it provides feed water heating to 340°C in all maintenance and emergency operation modes of the unit. The reliability of the high-pressure direct contact heater operation in this flow diagram is of major importance in relation to the danger of lead solidification in the tube space of the steam generator. Technical requirements to the design of the high-pressure direct contact heater for increasing the heat exchange efficiency are formulated based on the results of earlier studies with steam-water mixture as the heating medium. The results of studies of superheated steam condensation on jets presented in this study testify that feed water is additionally heated to the required temperature at the output of the installation. The influence of initial feed water parameters (outflow velocity and temperature) on the jet heating length is elucidated. The numerical approximation of the experimental data for determination of the jet heating length in the nominal and partial power unit loads is obtained. The results of the calculations are used to simplify the design of the water-supplying element for the direct contact feed water heater. The proposed design of direct contact feed water heater is characterized by simplicity and low metal intensity, which provides the installation reliability at the considered pressure level due to the minimum number of structural elements.

  8. Experimental and Analytical Performance of a Dual Brayton Power Conversion System

    Science.gov (United States)

    Lavelle, Thomas A.; Hervol, David S.; Briggs, Maxwell; Owen, A. Karl

    2009-01-01

    The interactions between two closed Brayton cycle (CBC) power conversion units (PCU) which share a common gas inventory and heat source have been studied experimentally using the Dual Brayton Power Conversion System (DBPCS) and analytically using the Closed- Cycle System Simulation (CCSS) computer code. Selected operating modes include steady-state operation at equal and unequal shaft speeds and various start-up scenarios. Equal shaft speed steady-state tests were conducted for heater exit temperatures of 840 to 950 K and speeds of 50 to 90 krpm, providing a system performance map. Unequal shaft speed steady-state testing over the same operating conditions shows that the power produced by each Brayton is sensitive to the operating conditions of the other due to redistribution of gas inventory. Startup scenarios show that starting the engines one at a time can dramatically reduce the required motoring energy. Although the DBPCS is not considered a flight-like system, these insights, as well as the operational experience gained from operating and modeling this system provide valuable information for the future development of Brayton systems.

  9. A novel self-powered MR damper: theoretical and experimental analysis

    Science.gov (United States)

    Xinchun, Guan; Yonghu, Huang; Yi, Ru; Hui, Li; Jinping, Ou

    2015-10-01

    This paper presents a novel magnetorheological (MR) damper with a self-powered capability, which is proposed to have energy harvesting and MR damping technologies integrated into a single device. Vibration energy harvesting mechanisms were adopted, based on ball-screw mechanisms and a rotary permanent magnet dc generator, to convert the external vibration energy into electrical energy to power the MR damping unit. The configuration and operating principles of the proposed self-powered MR damper were presented. Considering the core loss effect on the magnetic field, a theoretical analysis of the proposed MR damper was carried out and a mechanical model was developed. Finally, a prototype with a capacity of 10 kN was fabricated and experimentally investigated in both the direct-supply mode and the supply-with-rectifier mode. The results indicated that the proposed configuration is feasible and that both modes can realize good self-adaptability of the MR damping force. However, the direct-supply mode has a sag effect in the force-displacement curve and provides a lower energy-dissipating capacity than the direct-supply mode does under the same conditions.

  10. Experimental Evaluation of a Water Shield for a Surface Power Reactor

    Science.gov (United States)

    Pearson, J. Boise; Reid, Robert S.

    2006-01-01

    As part of the Vision for Space Exploration the end of the next decade will bring man back to the surface of the moon. One of the most critical issues for the establishment of human presence on the moon will be the availability of compact power sources. The establishment of man on the moon will require power from greater than 10's of kWt's in follow on years. Nuclear reactors are extremely we11 suited to meet the needs for power generation on the lunar or Martian surface. reactor system. Several competing concepts exist for lightweight, safe, robust shielding systems such as a water shield, lithium hydride (LiH), Boron Carbide, and others. Water offers several potential advantages, including reduced cost, reduced technical risk, and reduced mass. Water has not typically been considered for space reactor applications because of the need for gravity to remove the potential for radiation streaming paths. The water shield concept relies on predictions of passive circulation of the shield water by natural convection to adequately cool the shield. This prediction needs to be experimentally evaluated, especially for shields with complex geometries. MSFC has developed the experience and fac necessary to do this evaluation in the Early Flight Fission - Test Facility (EFF-TF).

  11. Simulation of the PEM fuel cell hybrid power train of an automated guided vehicle and comparison with experimental results

    OpenAIRE

    Veenhuizen, Bram; Bosma, J.C.N.

    2009-01-01

    At HAN University research has been started into the development of a PEM fuel cell hybrid power train to be used in an automated guided vehicle. For this purpose a test facility is used with the possibility to test all important functional aspects of a PEM fuel cell hybrid power train. In this paper the first experimental results of the testing of the power train are presented, driving a drive cycle designed especially for this automated guided vehicle. Experimental results are compared to r...

  12. Multiplexed Post-Experimental Monoisotopic Mass Refinement ( m PE-MMR) to Increase Sensitivity and Accuracy in Peptide Identifications from Tandem Mass Spectra of Cofragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Madar, Inamul Hasan [Laboratory; Ko, Seung-Ik [Laboratory; Kim, Hokeun [Laboratory; Mun, Dong-Gi [Laboratory; Kim, Sangtae [Biological; Smith, Richard D. [Biological; Lee, Sang-Won [Laboratory

    2016-12-22

    Mass spectrometry (MS)-based proteomics, which uses high-resolution hybrid mass spectrometers such as the quadrupole-orbitrap mass spectrometer, can yield tens of thousands of tandem mass (MS/MS) spectra of high resolution during a routine bottom-up experiment. Despite being a fundamental and key step in MS-based proteomics, the accurate determination and assignment of precursor monoisotopic masses to the MS/MS spectra remains difficult. The difficulties stem from imperfect isotopic envelopes of precursor ions, inaccurate charge states for precursor ions, and cofragmentation. We describe a composite method of utilizing MS data to assign accurate monoisotopic masses to MS/MS spectra, including those subject to cofragmentation. The method, “multiplexed post-experiment monoisotopic mass refinement” (mPE-MMR), consists of the following: multiplexing of precursor masses to assign multiple monoisotopic masses of cofragmented peptides to the corresponding multiplexed MS/MS spectra, multiplexing of charge states to assign correct charges to the precursor ions of MS/ MS spectra with no charge information, and mass correction for inaccurate monoisotopic peak picking. When combined with MS-GF+, a database search algorithm based on fragment mass difference, mPE-MMR effectively increases both sensitivity and accuracy in peptide identification from complex high-throughput proteomics data compared to conventional methods.

  13. Experimental study for quantative aging evaluation of epoxy liner in BWR nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Na, H. S. [KEPRI, Taejon (Korea, Republic of); Song, Y. C.; Kim, N. Y. [Korea Univ. of Educational Technology, Chonnon (Korea, Republic of)

    2001-10-01

    The purpose of this study is an experimental approach to quantitatively evaluate the aging status of epoxy coating onto containment structure in BWR nuclear power plant. Based on accelerated aging experiment for 64 days, adhesion test was performed to evaluate an physical bonding. To compare with adhesion data, both impedance data by UT and data by thermal gravimetric analysis were obtained during experiment. At almost 50% of adhesion force decrease, it was identified that aging phenamena of epoxy such as pine hole, blistering was discovered. Coating to establish aging status of epoxy, relations among three kinds of different data were analyze. By compatibility of these data, physical aging situation of as-built epoxy coating was figured out. The possibility to develop new methodology of time-dependent aging status on epoxy coating was identified.

  14. An experimental model of the evaporative cooling system of a single powerful LED

    Directory of Open Access Journals (Sweden)

    Shatskiy Evgeny

    2017-01-01

    Full Text Available An experimental model of the evaporative cooling system of a single powerful LED with a natural circulation of the coolant capable of removing a heat flux density of more than 1 kW / cm2 is created. It is shown that on the finned surfaces the overheating relative to the saturation temperature in comparison with a smooth surface decreases up to three times for the heater with a diameter of 5 mm. There is up to two times increase in heat transfer coefficient on finned surfaces as compared to the smooth ones. For finned surfaces on the heater with a diameter of 1 mm the surface overheating relative to the saturation temperature decreases in four times. More than three times increase is observed for the heat transfer coefficient on finned surfaces as compared to the smooth ones.

  15. Conceptual design of superconducting magnet systems for the Argonne Tokamak Experimental Power Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.T.; Turner, L.R.; Mills, F.E.; DeMichele, D.W.; Smelser, P.; Kim, S.H.

    1976-01-01

    As an integral effort in the Argonne Tokamak Experimental Power Reactor Conceptual Design, the conceptual design of a 10-tesla, pure-tension superconducting toroidal-field (TF) coil system has been developed in sufficient detail to define a realistic design for the TF coil system that could be built based upon the current state of technology with minimum technological extrapolations. A conceptual design study on the superconducting ohmic-heating (OH) coils and the superconducting equilibrium-field (EF) coils were also completed. These conceptual designs are developed in sufficient detail with clear information on high current ac conductor design, cooling, venting provision, coil structural support and zero loss poloidal coil cryostat design. Also investigated is the EF penetration into the blanket and shield.

  16. An experimental model of the evaporative cooling system of a single powerful LED

    Science.gov (United States)

    Shatskiy, Evgeny

    2017-10-01

    An experimental model of the evaporative cooling system of a single powerful LED with a natural circulation of the coolant capable of removing a heat flux density of more than 1 kW / cm2 is created. It is shown that on the finned surfaces the overheating relative to the saturation temperature in comparison with a smooth surface decreases up to three times for the heater with a diameter of 5 mm. There is up to two times increase in heat transfer coefficient on finned surfaces as compared to the smooth ones. For finned surfaces on the heater with a diameter of 1 mm the surface overheating relative to the saturation temperature decreases in four times. More than three times increase is observed for the heat transfer coefficient on finned surfaces as compared to the smooth ones.

  17. Theoretical and experimental investigation of a rectenna element for microwave power transmission

    Science.gov (United States)

    Mcspadden, James O.; Yoo, Taewhan; Chang, Kai

    1992-01-01

    A microstrip measurement system has been designed to analyze packaged GaAs Schottky barrier diodes under small and large signal conditions. The nonlinear equivalent circuit parameters of the diode are determined using a small signal test method that analyzes the diode's scattering parameters at various bias levels. The experimental results of a 2.45 GHz diode are verified using a nonlinear circuit simulation program based on a multireflection algorithm. A 35 GHz rectenna has been built using a microstrip patch antenna and Ka-band mixer diode. The measured efficiency was 29 percent at 120 mW input power. A frequency selective surface is designed using an equivalent circuit model to reduce the second harmonic radiations for a 2.45 GHz rectenna. Theoretical results are found to be in fairly good agreement with experiments.

  18. The Experimental Study of Heat Waste Conversion into Useful Electric Power

    Directory of Open Access Journals (Sweden)

    FALOTA Horea

    2009-05-01

    Full Text Available This paper presents the practical results ofthe design solutions, executing and experimentaltesting of a prototype model of o thermoelectricgenerator, based on the conversion of residualthermical energy into electric power, by improving theSeebeck effect. To this purpose, high performancethermoelectric modules have been used, taken from therecent production of the American Corporation Hi-ZTechnology. The prototype thermoelectric generatorbuilt for a demonstrative purposes has got the lowefficiency category. The results taken from the testsand experimental measurements have showntheimportance of the constructive solution of materialsand technologies that have been used. These resultsdirect the functional reliability growth and energyconversion efficiency. The functional performance andconversion capability evolution are directly conditionedby progress that will be registered through heavyresearch for the performance of the semiconductivematerials with thermoelectric characteristics stressedout by the so-called high figure of merit.

  19. China's experimental pragmatics of "Scientific development" in wind power: Algorithmic struggles over software in wind turbines

    DEFF Research Database (Denmark)

    Kirkegaard, Julia

    2016-01-01

    This article presents a case study on the development of China's wind power market. As China's wind industry has experienced a quality crisis, the Chinese government has intervened to steer the industry towards a turn to quality, indicating a pragmatist and experimental mode of market development....... This increased focus on quality, to ensure the sustainable and scientific development of China's wind energy market, requires improved indigenous Chinese innovation capabilities in wind turbine technology. To shed light on how the turn to quality impacts upon the industry and global competition, this study...... adopts the micro-processual, socio-technical, relational and empiricist lens of Science & Technology Studies (STS). It illustrates how Sino-foreign collaborative relations around the core technology of software (in control systems and simulation tools) have become politicised, and how controversies...

  20. EEG Analysis during complex diagnostic tasks in Nuclear Power Plants - Simulator-based Experimental Study

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jun Su; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2005-07-01

    In literature, there are a lot of studies based on EEG signals during cognitive activities of human-beings but most of them dealt with simple cognitive activities such as transforming letters into Morse code, subtraction, reading, semantic memory search, visual search, memorizing a set of words and so on. In this work, EEG signals were analyzed during complex diagnostic tasks in NPP simulator-based environment. Investigated are the theta, alpha, beta, and gamma band EEG powers during the diagnostic tasks. The experimental design and procedure are represented in section 2 and the results are shown in section 3. Finally some considerations are discussed and the direction for the further work is proposed in section 4.

  1. Experimental validation of a sub-surface model of solar power for distributed marine sensor systems

    Science.gov (United States)

    Hahn, Gregory G.; Cantin, Heather P.; Shafer, Michael W.

    2016-04-01

    The capabilities of distributed sensor systems such as marine wildlife telemetry tags could be significantly enhanced through the integration of photovoltaic modules. Photovoltaic cells could be used to supplement the primary batteries for wildlife telemetry tags to allow for extended tag deployments, wherein larger amounts of data could be collected and transmitted in near real time. In this article, we present experimental results used to validate and improve key aspects of our original model for sub-surface solar power. We discuss the test methods and results, comparing analytic predictions to experimental results. In a previous work, we introduced a model for sub-surface solar power that used analytic models and empirical data to predict the solar irradiance available for harvest at any depth under the ocean's surface over the course of a year. This model presented underwater photovoltaic transduction as a viable means of supplementing energy for marine wildlife telemetry tags. The additional data provided by improvements in daily energy budgets would enhance the temporal and spatial comprehension of the host's activities and/or environments. Photovoltaic transduction is one method that has not been widely deployed in the sub-surface marine environments despite widespread use on terrestrial and avian species wildlife tag systems. Until now, the use of photovoltaic cells for underwater energy harvesting has generally been disregarded as a viable energy source in this arena. In addition to marine telemetry systems, photovoltaic energy harvesting systems could also serve as a means of energy supply for autonomous underwater vehicles (AUVs), as well as submersible buoys for oceanographic data collection.

  2. Experimental study of defoaming by air-borne power ultrasonic technology

    Science.gov (United States)

    Rodríguez, Germán; Riera, Enrique; Gallego-Juárez, Juan A.; Acosta, Víctor M.; Pinto, Alberto; Martínez, Ignacio; Blanco, Alfonso

    2010-01-01

    Foam is a dispersion of gas in a liquid in which the distances between the gas bubbles are very small. Foams are frequently generated in the manufacture of many products as result from the aeration and agitation of liquids, from the vaporization of the liquid and also from biological or chemical reactions. Foams are generally an unwanted product in industrial processes because they cause difficulties in process control and in equipment operation. The most efficient conventional method for defoaming is the use of chemical agents but they contaminate the product. High-intensity ultrasonic waves offer a clean procedure to break foam bubbles. The potential use of ultrasound for foam breaking that was known since many years has been recently reinforced by the application of a new type of ultrasonic defoamer based on the stepped-plate high-power transducers to generate air-borne ultrasound. This defoamer has been successfully applied in several industrial problems such as the control of excess foam produced during the filling operation of bottles and cans on high-speed canning lines and in fermenting vessels and other reactors of great dimensions. The treatment of such industrial problems requires the proper characterization and quantification of the main parameters involved in the mechanisms of the defoaming effect. This paper deals with an experimental study about the separate influence of such parameters with the aim of improving the application of the stepped-plate power ultrasonic generators for the production of the defoaming action on industrial processes

  3. ESTIMATION OF ROUTINE DISCHARGE OF RADIONUCLIDES ON POWER REACTOR EXPERIMENTAL RDE

    Directory of Open Access Journals (Sweden)

    P.M. Udiyani

    2017-02-01

    Full Text Available Experimental power reactor (RDE which is planned to be constructed by BATAN is a kind of High Temperature Gas Cooled Reactor (HTGR with 10 MWth power. HTGR is a helium gas-cooled reactor with TRISO-coated fuel that is able to confine fission products remained in the core. Although the fission products released into the environment are very small, in order to comply the regulations the study about environmental radiation on normal or routine operation condition need to be performed. Estimation of radiology in the environment involves the source term released into the environment under routine operation condition. The purpose of this study is to estimate the source term released into the environment based on postulation of normal or routine operations of RDE. The research approach starts with an assumption that there are defects and impurities in the TRISO fuel because of limitation during the fabrication. Mechanism of fission products release from the fuel to the environment was created based on the safety features design of RDE. Radionuclides inventories in the reactor were calculated using ORIGEN-2 whose library has been modified for HTGR type, and the assumptions of defects of the TRISO fuel and release fraction for each compartment of RDE safety system used a reference parameter. The results showed that the important source terms of RDE are group of noble gases (Kr and Xe, halogen (I, Sr, Cs, H-3, and Ag. Activities of RDE source terms for routine operations have no significant difference with the HTGR source terms with the same power. Keywords: routine discharge, radionuclide, source term, RDE, HTGR

  4. Experimental Determination of Operating and Maximum Power Transfer Efficiencies at Resonant Frequency in a Wireless Power Transfer System using PP Network Topology with Top Coupling

    Science.gov (United States)

    Ramachandran, Hema; Pillai, K. P. P.; Bindu, G. R.

    2017-08-01

    A two-port network model for a wireless power transfer system taking into account the distributed capacitances using PP network topology with top coupling is developed in this work. The operating and maximum power transfer efficiencies are determined analytically in terms of S-parameters. The system performance predicted by the model is verified with an experiment consisting of a high power home light load of 230 V, 100 W and is tested for two forced resonant frequencies namely, 600 kHz and 1.2 MHz. The experimental results are in close agreement with the proposed model.

  5. Experimental evaluation of the wind effects on an operating power transmission tower

    Directory of Open Access Journals (Sweden)

    Hermes Carvalho

    Full Text Available Abstract Static and dynamic effects on power transmission towers can be evaluated by methodologies available in codes, which suggest the use of linear static analysis. By using numerical simulations, it is possible to observe the strong influence of the geometric nonlinear behavior of transmission cables. Dynamic effects also strongly influence this behavior, with the possibility of resonance between the cables and the structure, but up to the moment, the existent analysis procedures have not been completely validated on an experimental basis. In order to validate a complete analysis methodology, experimental procedures are proposed for a suspension tower of a 138kV transmission line in use. A tridimensional anemometer was installed on this structure in order to measure the values and directions of wind speeds. Simultaneous strain values were collected on the main elements of the tower through optical extensometers. Optical sensor technology with Fiber Bragg Gratings was used, due to the characteristic of immunity to the electromagnetic field occasioned by high electric currents. The string swing angle was evaluated through a high-resolution camera and a tridimensional accelerometer. With this instrumentation, it is possible to create a complete database that correlates wind speeds with the responses of the structural set. At the moment, 5 months of data have been collected and the instrumentation is in the final testing phase and synchronized. After this step, real-time measurements will be performed.

  6. A Flexible Experimental Laboratory for Distributed Generation Networks Based on Power Inverters

    Directory of Open Access Journals (Sweden)

    Jaume Miret

    2017-10-01

    Full Text Available In the recently deregulated electricity market, distributed generation based on renewable sources is becoming more and more relevant. In this area, two main distributed scenarios are focusing the attention of recent research: grid-connected mode, where the generation sources are connected to a grid mainly supplied by big power plants, and islanded mode, where the distributed sources, energy storage devices, and loads compose an autonomous entity that in its general form can be named a microgrid. To conduct a successful research in these two scenarios, it is essential to have a flexible experimental setup. This work deals with the description of a real laboratory setup composed of four nodes that can emulate both scenarios of a distributed generation network. A comprehensive description of the hardware and software setup will be done, focusing especially in the dual-core DSP used for control purposes, which is next to the industry standards and able to emulate real complexities. A complete experimental section will show the main features of the system.

  7. Laser- and gamma-induced transformations of optical spectra of indium-doped sodium borate glass

    CERN Document Server

    Kopyshinsky, O V; Zelensky, S E; Danilchenko, B A; Shakhov, O P

    2003-01-01

    The optical absorption and luminescence properties of indium-doped sodium borate glass irradiated by gamma-rays and by powerful UV lasers within the impurity-related absorption band are investigated experimentally. It is demonstrated that both the laser- and gamma-irradiation cause similar transformations of optical spectra in the UV and visible regions. The changes of the spectra observed are described with the use of a model which includes three types of impurity centres formed by differently charged indium ions.

  8. Baseline Experimental Results on the Effect of Oil Temperature on Shrouded Meshed Spur Gear Windage Power Loss

    Science.gov (United States)

    Delgado, Irebert R.; Hurrell, Michael

    2017-01-01

    Rotorcraft gearbox efficiencies are reduced at increased surface speeds due to viscous and impingement drag on the gear teeth. This windage power loss can affect overall mission range, payload, and frequency of transmission maintenance. Experimental and analytical studies on shrouding for single gears have shown it to be potentially effective in mitigating windage power loss. Efficiency studies on unshrouded meshed gears have shown the effect of speed, oil viscosity, temperature, load, lubrication scheme, etc. on gear windage power loss. The open literature does not contain experimental test data on shrouded meshed spur gears. Gear windage power loss test results are presented on shrouded meshed spur gears at elevated oil inlet temperatures and constant oil pressure both with and without shrouding. Shroud effectiveness is compared at four oil inlet temperatures. The results are compared to the available literature and follow-up work is outlined.

  9. Design and experimental investigation of an oxy-fuel combustion system for magnetohydrodynamic power extraction

    Science.gov (United States)

    Hernandez, Manuel Johannes

    designed to produce gas velocities of 2000 m/s gas and temperatures within the following range of 2800-3000 K. In the injection system, the momentum flux ratio (MFR) was estimated to be 16. The heat loss fraction in this oxy-combustion system, based on CFD and analytical calculations, at optimal operating conditions, was estimated to be less than 10 percent. Furthermore, the heat transfer design removed approximately 7 MW/m2. The experimental performance of oxy-combustion systems demonstrates promise for advanced power generation applications.

  10. Experimental Investigation of Heterogeneous Power Systems on the Basis of Lyophobic Liquids and Porous Media

    Directory of Open Access Journals (Sweden)

    V. D. Borman

    2014-01-01

    Full Text Available The use of non-traditional ways for energy accumulation (absorption is a reserve to increase efficiency of accumulating and damping devices. The work is aimed at experimental and theoretical verification of possibility to create the accumulating and energy damping devices based on the heterogeneous systems (HS. The HS includes a couple i.e. a porous body (silochromes with pore diameter from 20 nm to 360 nm and a lyophobic (non-wetting liquid (Wood's alloy. The paper briefly presents provisions of the theory of processes in HS based on the kinetics of percolation transition that allows us to calculate power, power and temporary characteristics of devices and prove the methods for choosing the couples for HS with the specified characteristics. It explains effect of hysteresis function of changing liquid volume that fills a porous body and outflows from it under the differential pressure, as well as conditions to realize effect of non-outflowing liquid after removal of the differential pressure thanks to which energy accumulation in HS is possible. The stand diagram, device parameters to study static and dynamic processes in HS, and measurement system characteristics are provided. Research results of static processes to fill (outflow pores of various silochromes with Wood's alloy are presented. It is shown that among considered HS the most efficient one is the HS possessing S-120 silochrome, hexamethyldisilazane-modified. The certain filling pores specific energy of HS made 71 J/g, while the outflow specific energy was 28 J/g. The paper presents a scheme of device model damping a force impact on the support. Test results of spring and hydraulic dampers and the model, as well, with HS based on silochromes with various lyophobic liquids are given. High HS efficiency that allows the 4 times less impact value is shown. Further researches concern a development of engineering techniques to design and optimize the HS parameters and a choice of the most

  11. Selection of the most powerful predictors for the evaluation of hepatic steatosis grade: An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Su Zhongzhen [Department of Radiology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province (China); Shan Hong [Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province (China)], E-mail: gzshsums@public.guangzhou.gd.cn; He Bingjun; Lv Wentian; Meng Xiaochun; Wang Jin; Zhu Kangshun [Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province (China); Yang Yang; Chen Guihua [Department of Liver Transplantation, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong Province (China)

    2009-10-15

    Purpose: To select the most powerful predictors for the evaluation of hepatic steatosis grade. Methods and materials: Forty-five healthy New Zealand rabbits were randomly divided into one normal control group and three experimental groups. Hepatic steatosis models were established by feeding a high-fat, high-sugar diet and drinking water containing 5% ethanol. Twenty-two variable indexes were measured using general observation, biochemical examination, ultrasonography, computed tomography (CT), and proton magnetic resonance spectroscopy (MRS). Univariate analysis, correlation analysis, and stepwise regression analysis were used to make the selection of the most powerful predictors. ROC analysis was used to compare the diagnostic efficacy of single index with combined index (Y) expressed by a regression equation. Results: Based on statistical analysis, there were 12 variable indexes with significant differences among groups, which correlated with hepatic steatosis grade: liver weight, hepatic index, liver CT value, liver-to-muscle attenuation ratio, {sup 1}H MRS fat peak value, fat peak area, fat-to-water peak area ratio, fat percentage, ultrasound attenuation coefficient, serum aspartate aminotransferase, total cholesterol (TC) and triglycerides. Among them hepatic index, liver CT value and serum TC were selected as the most powerful predictors for hepatic steatosis grade with correlation coefficients of 0.709, -0.764, and 0.886, respectively. The regression equation was: Y = 1.975 + 3.906 x 10{sup -2}X{sub 1} + 0.369X{sub 2} - 2.84 x 10{sup -2}X{sub 3}, where Y = hepatic steatosis grade, X{sub 1} = TC, X{sub 2} = hepatic index, and X{sub 3} = liver CT value. ROC analysis displayed PPV, NPV, curve area of combined index (Y) were superior to simple index (hepatic index, liver CT value and serum TC) in evaluating hepatic steatosis grade, and they were nearly 1.0000, 1.0000 and 1.000, respectively. Conclusions: Combined application of several diagnostic methods is

  12. Power

    OpenAIRE

    Bowles, Samuel; Gintis, Herbert

    2007-01-01

    We consider the exercise of power in competitive markets for goods, labour and credit. We offer a definition of power and show that if contracts are incomplete it may be exercised either in Pareto-improving ways or to the disadvantage of those without power. Contrasting conceptions of power including bargaining power, market power, and consumer sovereignty are considered. Because the exercise of power may alter prices and other aspects of exchanges, abstracting from power may miss essential a...

  13. Experimental studies of the NaCs 12(0+) [71Σ+] state: Spin-orbit and non-adiabatic interactions and quantum interference in the 12(0+) [71Σ+] and 11(0+) [53Π0 ] emission spectra

    Science.gov (United States)

    Faust, C.; Jones, J.; Huennekens, J.; Field, R. W.

    2017-03-01

    We present results from experimental studies of the 11(0+) and 12(0+) electronic states of the NaCs molecule. An optical-optical double resonance method is used to obtain Doppler-free excitation spectra. Selected data from the 11(0+) and 12(0+) high-lying electronic states are used to obtain Rydberg-Klein-Rees and Inverse Perturbation Approach potential energy curves. Interactions between these two electronic states are evident in the patterns observed in the bound-bound and bound-free fluorescence spectra. A model, based on two separate interaction mechanisms, is presented to describe how the wavefunctions of the two states mix. The electronic parts of the wavefunctions interact via spin-orbit coupling, while the individual rotation-vibration levels interact via a second mechanism, which is likely to be non-adiabatic coupling. A modified version of the BCONT program was used to simulate resolved fluorescence from both upper states. Parameters of the model that describe the two interaction mechanisms were varied until simulations were able to adequately reproduce experimental spectra.

  14. Experimental studies of the NaCs 12(0+) [71Σ+] state: Spin-orbit and non-adiabatic interactions and quantum interference in the 12(0+) [71Σ+] and 11(0+) [53Π0] emission spectra.

    Science.gov (United States)

    Faust, C; Jones, J; Huennekens, J; Field, R W

    2017-03-14

    We present results from experimental studies of the 11(0+) and 12(0+) electronic states of the NaCs molecule. An optical-optical double resonance method is used to obtain Doppler-free excitation spectra. Selected data from the 11(0+) and 12(0+) high-lying electronic states are used to obtain Rydberg-Klein-Rees and Inverse Perturbation Approach potential energy curves. Interactions between these two electronic states are evident in the patterns observed in the bound-bound and bound-free fluorescence spectra. A model, based on two separate interaction mechanisms, is presented to describe how the wavefunctions of the two states mix. The electronic parts of the wavefunctions interact via spin-orbit coupling, while the individual rotation-vibration levels interact via a second mechanism, which is likely to be non-adiabatic coupling. A modified version of the BCONT program was used to simulate resolved fluorescence from both upper states. Parameters of the model that describe the two interaction mechanisms were varied until simulations were able to adequately reproduce experimental spectra.

  15. Theoretical and experimental study of high-magnetic-field XMCD spectra at the L{sub 2,3} absorption edges of mixed-valence rare-earth compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Akio [Photon Factory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Matsuda, Yasuhiro H [Institute for Solid State Physics, University of Tokyo, Chiba 277-8581 (Japan); Nojiri, Hiroyuki, E-mail: kotani@post.kek.j [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2009-11-15

    X-ray magnetic circular dichroism(XMCD) spectra at the L{sub 2,3} edges of mixed-valence rare-earth compounds in high magnetic fields are studied both theoretically and experimentally. The theoretical study is based on a new framework proposed recently by Kotani. The Zeeman splitting of 4f states, the mixed-valence character of 4f states, and the 4f-5d exchange interaction are incorporated into a single impurity Anderson model. New XMCD experiments in high magnetic fields up to 40 T are carried out for the mixed-valence compounds EuNi{sub 2}(Si{sub 0.18}Ge{sub 0.82}){sub 2} and YbInCu{sub 4} by using a miniature pulsed magnet, which was developed recently by Matsuda et al. The XMCD data are taken at 5 K by transmission measurements for incident X-rays with {+-} helicities at BL39XU in SPring-8. After giving a survey on recent developments in the theory of XMCD spectra for mixed-valence Ce and Yb compounds, we calculate the XMCD spectra of YbInCu{sub 4} at the field-induced valence transition around 32 T by applying the recent theoretical framework and by newly introducing at 32 T a discontinuous change in the Yb 4f level and that in the hybridization strength between the Yb 4f and conduction electrons. The calculated results are compared with the experimental ones.

  16. Theoretical and experimental study of a wireless power supply system for moving low power devices in ferromagnetic and conductive medium

    Science.gov (United States)

    Safour, Salaheddine; Bernard, Yves

    2017-10-01

    This paper focuses on the design of a wireless power supply system for low power devices (e.g. sensors) located in harsh electromagnetic environment with ferromagnetic and conductive materials. Such particular environment could be found in linear and rotating actuators. The studied power transfer system is based on the resonant magnetic coupling between a fixed transmitter coil and a moving receiver coil. The technique was utilized successfully for rotary machines. The aim of this paper is to extend the technique to linear actuators. A modeling approach based on 2D Axisymmetric Finite Element model and an electrical lumped model based on the two-port network theory is introduced. The study shows the limitation of the technique to transfer the required power in the presence of ferromagnetic and conductive materials. Parametric and circuit analysis were conducted in order to design a resonant magnetic coupler that ensures good power transfer capability and efficiency. A design methodology is proposed based on this study. Measurements on the prototype show efficiency up to 75% at a linear distance of 20 mm.

  17. Design study of toroidal magnets for tokamak experimental power reactors. [NbTi alloys

    Energy Technology Data Exchange (ETDEWEB)

    Stekly, Z.J.J.; Lucas, E.J. (eds.)

    1976-12-01

    This report contains the results of a six-month study of superconducting toroidal field coils for a Tokamak Experimental Power Reactor to be built in the late 1980s. The designs are for 8 T and 12 T maximum magnetic field at the superconducting winding. At each field level two main concepts were generated; one in which each of the 16 coils comprising the system has an individual vacuum vessel and the other in which all the coils are contained in a single vacuum vessel. The coils have a D shape and have openings of 11.25 m x 7.5 m for the 8 T coils and 10.2 m x 6.8 m for the 12 T coils. All the designs utilize rectangular cabled conductor made from copper stabilized Niobium Titanium composite which operates at 4.2 K for the 8 T design and at 2.5 K for the 12 T design. Manufacturing procedures, processes and schedule estimates are also discussed.

  18. Aspect of Dynamic Simulation and Experimental Research Studies on Hybrid Pneumatic Power System

    Directory of Open Access Journals (Sweden)

    K. David Huang

    2010-01-01

    Full Text Available A Hybrid Pneumatic Power System (HPPS has been developed for several years with the major aim of reducing the vehicle fuel consumption, environment pollution and enhancing the vehicle performance as well. Comparing with the conventional hybrid system, HPPS replaces the battery's electrochemical energy with a high-pressure air storage tank and enables the internal combustion engine (ICE to function at its sweet spot. Besides, the HPPS, which effectively merges both the high-pressure air flow from the storage tank and the recycled exhaust flow from the ICE, thereby increases the thermal efficiency of the ICE and transforms the merged flow energy into mechanical energy using a high-efficiency turbine. This paper focuses on the major research process into HPPSs, including overall dynamic simulation and experimental validation. By using the simulation tool ITI-Sim, this research demonstrates an experiment which can be operated precisely according to the requirements of various driving conditions under which a car actually runs on the road in accordance with the regulated running vehicle test mode. HPPS is expected to increase the performance of the entire system from 15% to 39%, and is likely to replace the traditional system in the coming years.

  19. Experimental study of the mode instability onset threshold in high-power FA-LPF lasers.

    Science.gov (United States)

    Malleville, Marie-Alicia; Dauliat, Romain; Benoît, Aurélien; Leconte, Baptiste; Darwich, Dia; Jeu, Rémi du; Jamier, Raphaël; Schuster, Kay; Roy, Philippe

    2017-12-15

    We report here on an experimental investigation of the temporal behavior of transverse mode instabilities into "fully aperiodic large-pitch fibers" (FA-LPFs) operated in high-power continuous-wave laser configuration. To ensure an effective transverse single-mode emission into FA-LPFs, a perfect index matching between the active core and the background cladding materials (Δn=0) is required. The original design of such fibers enables an effective transverse single-mode emission by strengthening the higher-order mode delocalization out of the gain region, even for high heat load levels, consequently leading to the improvement of the beam spatial quality. The study was conducted over fibers of various gain region diameters, from 58 to 100 μm, for a refractive index mismatch Δn of about +8×10-5. The emitted beam is characterized using both M2 measurements and time traces to study the changeover of a stable temporal behavior to an unstable one.

  20. Does hypericin boost the efficacy of high-power laser? A preliminary experimental study on rats.

    Science.gov (United States)

    Zor, Murat; Goktas, Serdar; Yildirim, Ibrahim; Zorba, Unal Orhan; Basal, Seref; Alp, Bilal Firat; Kaya, Engin; Erogul, Osman

    2014-12-01

    Lasers are widely used in treating symptomatic benign prostatic hyperplasia. In current practice, potassium titanyl phosphate (KTP) lasers are the most common type of laser systems used. The aim here was to evaluate the rapid effect of high-power laser systems after application of hypericin. Experimental animal study conducted in the Department of Urology, Gülhane Military Medical Academy, Ankara, Turkey, in 2012. Sixteen rats were randomized into four groups: 120 W KTP laser + hypericin; 120 W KTP laser alone; 80 W KTP laser + hypericin; and 80 W KTP laser alone. Hypericin was given intraperitoneally two hours prior to laser applications. The laser incisions were made through the quadriceps muscle of the rats. The depth and the width of the laser incisions were evaluated histologically and recorded. To standardize the effects of the laser, we used the ratio of depth to width. These new values showed us the depth of the laser application per unit width. The new values acquired were evaluated statistically. Mean depth/width values were 231.6, 173.6, 214.1 and 178.9 in groups 1, 2, 3 and 4, respectively. The most notable result was that higher degrees of tissue penetration were achieved in the groups with hypericin (P laser applications.

  1. Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

    Science.gov (United States)

    Festing, Michael F W

    2014-01-01

    Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor. These benefits can be achieved at no extra cost. A small experiment investigating the effect of an antioxidant on the activity of a liver enzyme in four inbred mouse strains, which had two replications (blocks) separated by a period of two months, illustrates this approach. The widespread failure to use these designs more widely in research involving laboratory animals has probably led to a substantial waste of animals, money, and scientific resources and slowed down the development of new treatments for human and animal diseases. © The Author 2014. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Conceptual studies of toroidal field magnets for the tokamak (fusion) experimental power reactor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1976-11-01

    This report presents the results of ''Conceptual Studies of Toroidal Field Magnets for the Tokamak Experimental Power Reactor'' performed for the Energy Research and Development Administration, Oak Ridge Operations. Two conceptual coil designs are developed. One design approach to produce a specified 8 Tesla maximum field uses a novel NbTi superconductor design cooled by pool-boiling liquid helium. For a highest practicable field design, a unique NbSn/sub 3/ conductor is used with forced-flow, single-phase liquid helium cooling to achieve a 12 Tesla peak field. Fabrication requirements are also developed for these approximately 7 meter horizontal bore by 11 meter vertical bore coils. Cryostat design approaches are analyzed and a hybrid cryostat approach selected. Structural analyses are performed for approaches to support in-plane and out-of-plane loads and a structural approach selected. In addition to the conceptual design studies, cost estimates and schedules are prepared for each of the design approaches, major uncertainties and recommendations for research and development identified, and test coil size for demonstration recommended.

  3. Raman spectra of lithium compounds

    Science.gov (United States)

    Gorelik, V. S.; Bi, Dongxue; Voinov, Y. P.; Vodchits, A. I.; Gorshunov, B. P.; Yurasov, N. I.; Yurasova, I. I.

    2017-11-01

    The paper is devoted to the results of investigating the spontaneous Raman scattering spectra in the lithium compounds crystals in a wide spectral range by the fibre-optic spectroscopy method. We also present the stimulated Raman scattering spectra in the lithium hydroxide and lithium deuteride crystals obtained with the use of powerful laser source. The symmetry properties of the lithium hydroxide, lithium hydroxide monohydrate and lithium deuteride crystals optical modes were analyzed by means of the irreducible representations of the point symmetry groups. We have established the selection rules in the Raman and infrared absorption spectra of LiOH, LiOH·H2O and LiD crystals.

  4. Effect of CdSe nanoparticles on the fluorescence spectra of conjugate polymer P3HT: An experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Mastour, Nouha, E-mail: mastournouha@yahoo.fr; Bouchriha, Habib

    2016-11-25

    In this work we have investigated the effect of CdSe nanoparticles (Nps) on the fluorescence spectra of conjugate polymer Poly(3-hexylthiophene-2,5-diyl) (P3HT). The fluorescence intensity is significantly decreased in both solution and solid films by the incorporation of CdSe Nps. This observed effect in the nanocomposite P3HT-CdSe is analyzed by using the Franck–Condon theory which reproduces correctly the decrease of the fluorescence with the Nps concentration and permits to reach the Huang–Rhys factor and the relaxation energy which are shown efficient to explain the fluorescence quenching. - Highlights: • The effects of CdSe nanoparticles concentration on the fluorescence spectra of conjugate polymer P3HT are investigated. • Theoretical approach based on Franck–Condon analysis is proposed. • The Huang–Rhys factor and the relaxation energy as a function of the CdSe Nps are determined. • The fluorescence quenching has been explained.

  5. Analysis of the optimal fuel composition for the Indonesian experimental power reactor

    Energy Technology Data Exchange (ETDEWEB)

    Liem, Peng Hong [Nippon Advanced Information Service (NAIS Co., Inc.), Ibaraki (Japan); Sembiring, Tagor Malem [National Nuclear Energy Agency of Indonesia, Banten (Indonesia). Center for Nuclear Reactor Technology and Safety; Arbie, Bakri; Subki, Iyos [PT MOTAB Technology, Jakarta Barat (Indonesia)

    2017-03-15

    The optimal fuel composition of the 10 MWth Experimental Power Reactor (RDE), to be built by the Indonesian National Nuclear Energy Agency (BATAN), is a very important design parameter since it will directly affect the fuel cost, new and spent fuel storage capacity, and other back-end environmental burden. The RDE is a very small sized pebble-bed high temperature gas-cooled reactor (HTGR) with low enriched uranium (LEU) UO{sub 2} TRISO fuel under multipass or once-through-then-out fueling scheme. A scoping study on fuel composition parameters, namely heavy metal (HM) loading per pebble and uranium enrichment is conducted. All burnup, criticality calculations and core equilibrium search are carried out by using BATAN-MPASS, a general in-core fuel management code for pebble bed HTGRs, featured with many automatic equilibrium searching options as well as thermal-hydraulic calculation capability. The RDE User Requirement Document issued by BATAN is used to derive the main core design parameters and constraints. The scoping study is conducted over uranium enrichment in the range of 10 to 20 w/o and HM loading in the range of 4 g to 10 g/pebble. Fissile loading per unit energy generated (kg/GWd) is taken as the objective function for the present scoping study. The analysis results show that the optimal HM loading is around 8 g/pebble. Under the constraint of 80 GWd/t fuel discharge burnup imposed by the technical specification, the uranium enrichment for the optimal HM loading is approximately 13 w/o.

  6. Experimental Investigation of Shrouding on Meshed Spur Gear Windage Power Loss

    Science.gov (United States)

    Delgado, Irebert R.; Hurrell, Michael J.

    2017-01-01

    Windage power loss in high-speed gearboxes results in efficiency losses and increased heating due to drag on the gear teeth. Test results for meshed spur gear windage power loss are presented at ambient oil inlet temperatures, both with and without shrouding. The rate of windage power loss is observed to increase above a gear surface speed of 10,000 feet per minute (51 meters per second), similar to results presented in the literature. Shrouding is observed to become more effective above 15,000 feet per minute (76 meters per second), decreasing power loss by 10 percent at 25,000 feet per minute (127 meters per second). The need for gearbox oil drain slots limits the effectiveness of shrouding in reducing windage power loss. Windage power loss is observed to decrease with increasing gearbox temperatures and to increase with oil flow. Windage power losses for unshrouded meshed spur gears are 7 times greater than losses determined from unshrouded single spur gear tests. A 6- to 12-times increase in windage power loss is observed in the shrouded meshed spur gear data compared with shrouded single spur gear data. Based on this preliminary study, additional research is suggested to determine the effect of oil drain slot configurations, axial and radial shroud clearances, and higher gear surface speeds on windage power loss. Additional work is also suggested to determine the sensitivity of windage power loss to oil temperature and oil flow. Windage power loss for meshed spur gears tested in both the shrouded and unshrouded configurations is shown to be more than double versus windage power loss for the same spur gears run individually in the same shroud configurations. Further study of the physical processes behind these results is needed to optimize gearbox shrouds for minimum windage power loss.

  7. Evaluation of the efficacy of monthly oral administration of afoxolaner plus milbemycin oxime (NexGard Spectra(®), Merial) in the prevention of adult Spirocerca lupi establishment in experimentally infected dogs.

    Science.gov (United States)

    Beugnet, Frederic; Crafford, Dionne; de Vos, Christa; Kok, Dawid; Larsen, Diane; Fourie, Josephus

    2016-08-15

    The nematode Spirocerca lupi (Rudolphi, 1809) is widely distributed but mostly occurs sporadically with stable populations only in certain geographic areas. This helminth mainly infects dogs and wild canids. Primary pathology relates to migration of third stage larvae (L3) damaging the thoracic aorta and establishment of adults in nodules in the oesophagus. The objective of the present study was to evaluate the efficacy of milbemycin oxime in combination with afoxolaner (NexGard Spectra(®), Merial), administered monthly, in preventing establishment of adult worms after experimental infection. Two groups consisting of eight animals each were experimentally infected with 15 L3 on Days -28, -14 and -2, respectively (45 L3 per animal in total). Group 1 dogs served as untreated (negative) control, whereas animals in group 2 were treated with NexGard Spectra(®) at a minimum dose of 0.5mg/kg milbemycin oxime on Day 0 and from then onwards every 28 days up to Day 140 (six treatment occasions). Endoscopy was performed on Day 112 and for some animals also Day 140. Necropsy for worm recovery and nodule/lesion scoring was performed on Day 168. All eight animals in the control group (group 1) presented with 1-3 nodules and worm counts ranging from 9 to 41. Six animals in the NexGard Spectra(®) group presented with 1-4 nodules and worm counts ranging from 1 to 5. Significantly (p0.05) difference between groups with reference to number of nodules in the oesophagus. However, nodules in the control group were significantly (pNexGard Spectra(®) was administered 28 days after onset of inoculation, migrating and developing L3 caused damage to the aorta wall of animals in the treated group. Milbemycin oxime (administered as NexGard Spectra(®)) demonstrated effectiveness in reducing infection with adult Spirocerca lupi worms in the oesophagus. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Experimental and Theoretical Demonstration of Launch Power Optimization using a Subcarrier Fibre Non-linearity Monitor

    DEFF Research Database (Denmark)

    Petersen, Martin Nordal; Nielsen, Mads Lønstrup

    2005-01-01

    A simple method for optimising the launch power to a single or multispan optical transmission system using a new fibre nonlinearity monitor is described. Inserting a subcarrier into the data-band, it was possible to correlate the BER performance of the 10 Gbit/s signal to the power of the subcarr......A simple method for optimising the launch power to a single or multispan optical transmission system using a new fibre nonlinearity monitor is described. Inserting a subcarrier into the data-band, it was possible to correlate the BER performance of the 10 Gbit/s signal to the power...

  9. EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS

    Energy Technology Data Exchange (ETDEWEB)

    Arsalan Razani; Kwang J. Kim

    2000-10-28

    The annual progress report for the period of October 1, 1999 to September 30, 2000 on DOE/UNM grant number DE-FG26-98FT40148 discusses the progress on both the theoretical analysis of advanced power cycles and the experimental investigation of advanced falling film heat exchangers. The previously developed computer program for the triple cycle, based on the air standard cycle assumption, was modified to include actual air composition (%77.48 N{sub 2}, %20.59 O{sub 2}, %1.9 H{sub 2}O, and %0.03 CO{sub 2}). The actual combustion products were used in exergy analysis of the triple cycle. The effect of steam injection into the combustion chamber on its irreversibility, and the irreversibility of the entire cycle, was evaluated. A more practical fuel inlet condition and a better position of the feedwater heater in the steam cycle were used in the modified cycle. The effect of pinch point and the temperature difference between the combustion products, as well as the steam in the heat recovery steam generator on irreversibility of the cycle were evaluated. Design, construction, and testing of the multitube horizontal falling film condenser facility were completed. Two effective heat transfer additives (2-ethyl-1-hexanol and alkyl amine) were identified and tested for steam condensation. The test results are included. The condenser was designed with twelve tubes in an array of three horizontals and four verticals, with a 2-inch horizontal and 1.5-inch vertical in-line pitch. By using effective additives, the condensation heat transfer rate can be augmented as much as 30%, as compared to a heat transfer that operated without additives under the same operating condition. When heat transfer additives function effectively, the condensate-droplets become more dispersed and have a smaller shape than those produced without additives. These droplets, unlike traditional turbulence, start at the top portion of the condenser tubes and cover most of the tubes. Such a flow behavior can

  10. Scikit-spectra: Explorative Spectroscopy in Python

    Directory of Open Access Journals (Sweden)

    Adam Hughes

    2015-06-01

    Full Text Available Scikit-spectra is an intuitive framework for explorative spectroscopy in Python. Scikit-spectra leverages the Pandas library for powerful data processing to provide datastructures and an API designed for spectroscopy. Utilizing the new IPython Notebook widget system, scikit-spectra is headed towards a GUI when you want it, API when you need it approach to spectral analysis. As an application, analysis is presented of the surface-plasmon resonance shift in a solution of gold nanoparticles induced by proteins binding to the gold’s surface. Please refer to the scikit-spectra website for full documentation and support: http://hugadams.github.io/scikit-spectra/

  11. An experimental investigation of charge-dependent deviations from the Bethe stopping power formula

    DEFF Research Database (Denmark)

    Andersen, H.H.; Simonsen, H.; Sørensen, H.

    1969-01-01

    The stopping powers of aluminiun and tantalum for 5–13.5 MeV protons and deuterons and 8–20 MeV 3He and 4He have been measured. At identical velocities, the ratio between the stopping powers for the double-charged and the single-charged ions is systematically higher than the factor four predicted...

  12. The experimental design of postmortem studies: the effect size and statistical power.

    Science.gov (United States)

    Meurs, Joris

    2016-09-01

    The aim is of this study was to show the poor statistical power of postmortem studies. Further, this study aimed to find an estimate of the effect size for postmortem studies in order to show the importance of this parameter. This can be an aid in performing power analysis to determine a minimal sample size. GPower was used to perform calculations on sample size, effect size, and statistical power. The minimal significance (α) and statistical power (1 - β) were set at 0.05 and 0.80 respectively. Calculations were performed for two groups (Student's t-distribution) and multiple groups (one-way ANOVA; F-distribution). In this study, an average effect size of 0.46 was found (n = 22; SD = 0.30). Using this value to calculate the statistical power of another group of postmortem studies (n = 5) revealed that the average statistical power of these studies was poor (1 - β studies is considerable. In order to enhance statistical power of postmortem studies, power analysis should be performed in which the effect size found in this study can be used as a guideline.

  13. Design, implementation, and experimental validation of optimal power split control for hybrid electric trucks

    NARCIS (Netherlands)

    Keulen, T. van; Mullem, D. van; Jager, B. van; Kessels, J.T.B.A.; Steinbuch, M.

    2012-01-01

    Hybrid electric vehicles require an algorithm that controls the power split between the internal combustion engine and electric machine(s), and the opening and closing of the clutch. Optimal control theory is applied to derive a methodology for a real-time optimal-control-based power split

  14. Formulation and experimental evaluation of closed-form control laws for the rapid maneuvering of reactor neutronic power

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J.A. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Nuclear Reactor Lab.)

    1989-09-01

    This report describes both the theoretical development and the experimental evaluation of a novel, robust methodology for the time-optimal adjustment of a reactor's neutronic power under conditions of closed-loop digital control. Central to the approach are the MIT-SNL Period-Generated Minimum Time Control Laws' which determine the rate at which reactivity should be changed in order to cause a reactor's neutronic power to conform to a specified trajectory. Using these laws, reactor power can be safely raised by five to seven orders of magnitude in a few seconds. The MIT-SNL laws were developed to facilitate rapid increases of neutronic power on spacecraft reactors operating in an SDI environment. However, these laws are generic and have other applications including the rapid recovery of research and test reactors subsequent to an unanticipated shutdown, power increases following the achievement of criticality on commercial reactors, power adjustments on commercial reactors so as to minimize thermal stress, and automated startups. The work reported here was performed by the Massachusetts Institute of Technology under contract to the Sandia National Laboratories. Support was also provided by the US Department of Energy's Division of University and Industry Programs. The work described in this report is significant in that a novel solution to the problem of time-optimal control of neutronic power was identified, in that a rigorous description of a reactor's dynamics was derived in that the rate of change of reactivity was recognized as the proper control signal, and in that extensive experimental trials were conducted of these newly developed concepts on actual nuclear reactors. 43 refs., 118 figs., 11 tabs.

  15. Exciton dynamics in the chlorosomal antenna of the green bacterium Chloroflexus aurantiacus: experimental and theoretical studies of femtosecond pump-probe spectra.

    Science.gov (United States)

    Yakovlev, Andrey; Novoderezhkin, Vladimir; Taisova, Alexandra; Fetisova, Zoya

    2002-01-01

    Femtosecond absorption difference spectra were measured for chlorosomes isolated from the green bacterium Chloroflexus aurantiacus at room temperature. Using the relative difference absorption of the oligomeric BChl c and monomeric BChl a bands, the size of a unit BChl c aggregate as well as the exciton coherence size were estimated for the chlorosomal BChl c antenna under study. A quantitative fit of the data was obtained within the framework of the exciton model proposed before [Fetisova et al. (1996) Biophys J 71: 995-1010]. The size of the antenna unit was found to be 24 exciton-coupled BChl c molecules. The anomalously high bleaching value of the oligomeric B740 band with respect to the monomeric B795 band provided the direct evidence for a high degree of exciton delocalization in the chlorosomal B740 BChl c antenna. The effective delocalization size of individual exciton wavefunctions (the thermally averaged inverse participation ratio) in the chlorosomal BChl c antenna is 9.5, whereas the steady-state wavepacket corresponds to the coherence size (the inverse participation ratio of the density matrix) of 7.4 at room temperature.

  16. Statistical Power in Experimental Audit Studies: Cautions and Calculations for Matched Tests With Nominal Outcomes

    Science.gov (United States)

    Vuolo, Mike; Uggen, Christopher; Lageson, Sarah

    2016-01-01

    Given their capacity to identify causal relationships, experimental audit studies have grown increasingly popular in the social sciences. Typically, investigators send fictitious auditors who differ by a key factor (e.g., race) to particular experimental units (e.g., employers) and then compare treatment and control groups on a dichotomous outcome…

  17. Experimental Study on Desalination System Using the Waste Heat of Nuclear Power Plants and Solar Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Khaswneh, Khalid; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    In this study a new desalination system using the waste heat of nuclear power plant or solar energy system is under consideration. An experiment study will performed to evaluate the performance of the system. In this paper, the experimental design of the system and steady-state and transient analysis, using MATLAB and MARS code respectively, will be presented. A new desalination system using the waste heat from nuclear power plants or solar energy was proposed and the design of an experimental facility to evaluate the system's performance was presented. The analytical steady-state analysis using MATLAB and transient MARS calculations have been performed. An Experiment will be performed to verify the model. Moreover a feasibility study for the proposed design and a comparison with the conventional desalination system will be performed.

  18. Experimental Study on Relationship of Applied Power And Feeding Rate on Production of Polyurethane Nanofibre

    OpenAIRE

    Oteyaka, Mustafa; Ozel, E; YILDIRIM, M. M.

    2014-01-01

    In this work, a polymer of polyurethane (PU) was electrospun for 1 hour to create a scaffold under different conditions. A 3x3 general full factorial in a completely randomised design using three levels of two factors: power (W= 20, 22 and 25 Watts) and feeding rate (V=1.00, 1.25 and 1.50 ml/h) was used to assess the response pattern and to determine the combined effect of independent variables. The main effects for power (W) and feeding rate (V) and the power (W)*feeding rate (V) interaction...

  19. Experimental Study on Relationship of Applied Power And Feeding Rate on Production of Polyurethane Nanofibre

    OpenAIRE

    Oteyaka, Mustafa; Ozel, E; Yildirim, M.

    2011-01-01

    In this work, a polymer of polyurethane (PU) was electrospun for 1 hour to create a scaffold under different conditions. A 3x3 general full factorial in a completely randomised design using three levels of two factors: power (W= 20, 22 and 25 Watts) and feeding rate (V=1.00, 1.25 and 1.50 ml/h) was used to assess the response pattern and to determine the combined effect of independent variables. The main effects for power (W) and feeding rate (V) and the power (W)*feeding rate (V) interaction...

  20. Modelling of organic Rankine cycle power systems in off-design conditions: an experimentally-validated comparative study

    OpenAIRE

    Dickes, Rémi; Dumont, Olivier; Daccord, Rémi; Quoilin, Sylvain; Lemort, Vincent

    2017-01-01

    Because of environmental issues and the depletion of fossil fuels, the world energy sector is undergoing many changes toward increased sustainability. Among the many fields of research and development, power generation from low-grade heat sources is gaining interest and the organic Rankine cycle (ORC) is seen as one of the most promising technologies for such applications. In this paper, it is proposed to perform an experimentally-validated comparison of different modelling methods for the of...

  1. Experimental verification of a novel MEMS multi-modal vibration energy harvester for ultra-low power remote sensing nodes

    Science.gov (United States)

    Iannacci, J.; Sordo, G.; Serra, E.; Kucera, M.; Schmid, U.

    2015-05-01

    In this work, we discuss the verification and preliminary experimental characterization of a MEMS-based vibration Energy Harvester (EH) design. The device, named Four-Leaf Clover (FLC), is based on a circular-shaped mechanical resonator with four petal-like mass-spring cascaded systems. This solution introduces several mechanical Degrees of Freedom (DOFs), and therefore enables multiple resonant modes and deformation shapes in the vibrations frequency range of interest. The target is to realize a wideband multi-modal EH-MEMS device, that overcomes the typical narrowband working characteristics of standard cantilevered EHs, by ensuring flexible and adaptable power source to ultra-low power electronics for integrated remote sensing nodes (e.g. Wireless Sensor Networks - WSNs) in the Internet of Things (IoT) scenario, aiming to self-powered and energy autonomous smart systems. Finite Element Method simulations of the FLC EH-MEMS show the presence of several resonant modes for vibrations up to 4-5 kHz, and level of converted power up to a few μW at resonance and in closed-loop conditions (i.e. with resistive load). On the other hand, the first experimental tests of FLC fabricated samples, conducted with a Laser Doppler Vibrometer (LDV), proved the presence of several resonant modes, and allowed to validate the accuracy of the FEM modeling method. Such a good accordance holds validity for what concerns the coupled field behavior of the FLC EH-MEMS, as well. Both measurements and simulations performed at 190 Hz (i.e. out of resonance) showed the generation of power in the range of nW (Root Mean Square - RMS values). Further steps of this work will include the experimental characterization in a full range of vibrations, aiming to prove the whole functionality of the FLC EH-MEMS proposed design concept.

  2. Theoretical, experimental and numerical diagnose of critical power point of thermoelectric generators

    DEFF Research Database (Denmark)

    Chen, Min; Gao, Xin

    2014-01-01

    When a number of TEMs (thermoelectric modules) are connected in a series-parallel matrix and under mismatched temperature gradients, the overall maximum output power of the thermoelectric generator (TEG) may be lowered by certain TEMs with relatively smaller temperature difference. It is possible...... of the critical power point in the series and parallel TEM arrays. Secondly, experiments of a series-parallel hybrid interconnected TEG are presented to clearly quantify the theoretical analyses. Finally, the hierarchical simulation, based on the SPICE (simulation program with integrated circuit emphasis......) platform, is applied to estimate the critical power point. By numerically modeling the nonlinear physical processes of the TEG, the simulation can be used as an enabling technique in any model-based controller to dynamically minimize the mismatch power loss within the TEM matrix of any configuration...

  3. The Experimental Study of Heat Waste Conversion into Useful Electric Power

    National Research Council Canada - National Science Library

    FALOTA Horea; ILIE Beriliu Constantin; COMSA Catalin

    2009-01-01

    ... energy into electric power, by improving theSeebeck effect. To this purpose, high performancethermoelectric modules have been used, taken from therecent production of the American Corporation Hi-ZTechnology...

  4. Experimental Evaluation of Performance of Constant Power Prime-Mover Driven Isolated 3-φ SEIG for Pico-Hydro Power Generation System in Remote Mountainous Region of Himalayas

    Directory of Open Access Journals (Sweden)

    Rathore Umesh C.

    2016-01-01

    Full Text Available This paper presents the experimental evaluation of the performance of 3-φ self-excited induction generator (SEIG suitable for pico-hydro power generation system feeding domestic load in remote mountainous region. The use of induction generators is most suitable for renewable energy conversion systems due to their enormous advantages over conventional synchronous generators. Important features of induction generators include the simplicity in construction, ruggedness, simplified control, ease in maintenance and small size per generated kW. The performance characteristics of 3-φ SEIG feeding isolated load are evaluated using MATLAB-Simulink model based on the prevalent renewable energy sources inputs and loading conditions in mountainous terrain of Himalayas. The results are validated using an experimental set-up comprising of 3-φ, 3 HP induction motor run as 3- φ induction generator driven by 5HP, 4-pole DC shunt motor acting as prime-mover.

  5. Experimental investigations of overvoltages in 6kV station service cable networks of thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vukelja, P.I.; Naumov, R.M.; Drobnjak, G.V.; Mrvic, J.D. [Nikola Tesla Inst., Belgrade (Yugoslavia)

    1996-12-31

    The paper presents the results of experimental investigations of overvoltages on 6kV isolated neutral station service cable networks of thermal power plants. The overvoltages were recorded with capacitive voltage measurement systems made at the Nikola Tesla Institute. Wideband capacitive voltage measurement systems recorded a flat response from below power frequencies to 10MHz. Investigations of overvoltages were performed for appearance and interruption of metal earth faults, intermittent earth faults, switching operation of HV motors switchgear, switching operation of transformers switchgear, and transfer of the network supply from one transformer to another. On the basis of these investigations, certain measures are proposed for limiting overvoltages and for the reliability of station service of thermal power plants.

  6. FT-IR, UV-vis, 1H and 13C NMR spectra and the equilibrium structure of organic dye molecule disperse red 1 acrylate: a combined experimental and theoretical analysis.

    Science.gov (United States)

    Cinar, Mehmet; Coruh, Ali; Karabacak, Mehmet

    2011-12-01

    This study reports the characterization of disperse red 1 acrylate compound by spectral techniques and quantum chemical calculations. The spectroscopic properties were analyzed by FT-IR, UV-vis, (1)H NMR and (13)C NMR techniques. FT-IR spectrum in solid state was recorded in the region 4000-400 cm(-1). The UV-vis absorption spectrum of the compound that dissolved in methanol was recorded in the range of 200-800 nm. The (1)H and (13)C NMR spectra were recorded in CDCl(3) solution. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. A satisfactory consistency between the experimental and theoretical spectra was obtained and it shows that the hybrid DFT method is very useful in predicting accurate vibrational structure, especially for high-frequency region. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. A study on the electronic properties were performed by timedependent DFT (TD-DFT) and CIS(D) approach. To investigate non linear optical properties, the electric dipole moment μ, polarizability α, anisotropy of polarizability Δα and molecular first hyperpolarizability β were computed. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the compound can be a good candidate of nonlinear optical materials. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. The Shaping Power of Market Prices and Individual Choices on Preferences. An Experimental Investigation

    OpenAIRE

    Sergio Beraldo; Valerio Filoso; Marco Stimolo

    2014-01-01

    We repeatedly elicited individuals' Willingness to Accept (WTA) evaluations for an auctioned bad in an experimental setting in which truthful revelation is the (weakly) dominant strategy. We investigate whether the observation of supposedly irrelevant signals (the market price, the asks at either the bottom or the top of the distribution of asks) affect the elicited values. Our experimental sample was made up of 162 subjects partitioned in 18 independent markets characterized by different inf...

  8. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangyu, E-mail: chenxiangyu@binn.cas.cn, E-mail: ouyangwei@phy.ecnu.edu.cn; Jiang, Tao [Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083 (China); Sun, Zhuo; Ou-Yang, Wei, E-mail: chenxiangyu@binn.cas.cn, E-mail: ouyangwei@phy.ecnu.edu.cn [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China)

    2015-09-14

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm{sup 2}, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  9. [Paraplegic cycling using functional electrical stimulation. Experimental and model-based study of power output].

    Science.gov (United States)

    Szecsi, J; Krafczyk, S; Quintern, J; Fiegel, M; Straube, A; Brandt, T

    2004-12-01

    Cycling using functional electrical stimulation offers paraplegics the possibility of muscle and cardiovascular training as well as the chance for independent locomotion. To investigate whether this method might be suitable for a large group of paraplegics, the first German feasibility study of functional electrical stimulation (FES) cycling with seven paraplegic patients was started at the beginning of 2003. Even at the beginning of the study, and without training, these patients were able to drive distances of 0.5-1.6 km. To stimulate cardiovascular adaptation processes in the case of FES ergometer training or to cover useful distances in the case of FES cycling, a minimum amount of generated mechanical output power is required, which as a rule cannot be achieved yet. In this study, we point out two particular aspects of FES cycling, which impair power output: prolonged fatigue mode and viscous joint friction of the paraplegic FES cyclist. We discuss current possibilities for increasing output power and endurance.

  10. Experimental Analysis of Thermoelectric Heat Exchanger for Power Generation from Salinity Gradient Solar Pond Using Low-Grade Heat

    Science.gov (United States)

    Singh, Baljit; Baharin, Nuraida `Aadilia; Remeli, Muhammad Fairuz; Oberoi, Amandeep; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-05-01

    Salinity gradient solar ponds act as an integrated thermal solar energy collector and storage system. The temperature difference between the upper convective zone and the lower convective zone of a salinity gradient solar pond can be in the range of 40-60°C. The temperature at the bottom of the pond can reach up to 90°C. Low-grade heat (solar ponds is currently converted into electricity by organic Rankine cycle engines. Thermoelectric generators can operate at very low temperature differences and can be a good candidate to replace organic Rankine cycle engines for power generation from salinity gradient solar ponds. The temperature difference in a solar pond can be used to power thermoelectric generators for electricity production. This paper presents an experimental investigation of a thermoelectric generators heat exchanger system designed to be powered by the hot water from the lower convective zone of a solar pond, and cold water from the upper convective zone of a solar pond. The results obtained have indicated significant prospects of such a system to generate power from low-grade heat for remote area power supply systems.

  11. Power

    OpenAIRE

    Hafford-Letchfield, Trish

    2015-01-01

    This chapter looks at the concept of power in social work by focusing on what this means as a ‘professional’ and theorizes competing discourses of empowerment in social work and its key concepts, drawing in particular on the explanatory powers of critical theorist Michel Foucault (1991). The chapter problematizes the concept of power by explicitly drawing on both users’ and carers’ accounts from the literature to demonstrate different external and internal influences on the root causes of dis...

  12. Combined experimental and theoretical studies on the X-ray crystal structure, FT-IR, 1H NMR, 13C NMR, UV-Vis spectra, NLO behavior and antimicrobial activity of 2-hydroxyacetophenone benzoylhydrazone.

    Science.gov (United States)

    Sheikhshoaie, Iran; Ebrahimipour, S Yousef; Sheikhshoaie, Mahdeyeh; Rudbari, Hadi Amiri; Khaleghi, Moj; Bruno, Giuseppe

    2014-04-24

    A Schiff base ligand, 2-hydroxyacetophenone benzoylhydrazone (HL) was synthesized and fully characterized with FT-IR, elemental analyses, UV-Vis, (1)H NMR and (13)C NMR spectra. DFT calculations using B3LYP/6-31+G(d,p) and PW91/DZP are performed to optimize the molecular geometry. Optimized structures are used to calculate FT-IR, UV-Vis, (1)H NMR and (13)C NMR spectra of the compound. Also the energies of the frontier molecular orbitals (FMOs) have been determined. The results obtained from the optimization and spectral analyses are in good agreement with the experimental data. To investigate non-linear optical properties, the electric dipole moment (μ), polarizability (α) and molecular first hyperpolarizability (β) were computed. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the compound can be a good candidate of nonlinear optical materials. In addition, the minimal inhibitory concentration (MIC) of this compound against Staphylococcus aureus, and Candida albicans was determined. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Experimental investigation of the hyperfine spectra of Pr I-lines: Discovery of new fine structure levels with high angular momentum

    Science.gov (United States)

    Siddiqui, Imran; Khan, Shamim; Windholz, Laurentius

    2014-05-01

    We present 66 even and 58 odd parity newly discovered fine structure levels of Pr I with high angular momentum: J = 15/2, 17/2 and 19/2 and 21/2. Spectral lines in the range 4200 Å to 7500 Å were experimentally investigated using laser induced fluorescence spectroscopy in a hollow cathode discharge lamp. The levels were discovered by analysis of the recorded hyperfine patterns of the investigated transitions. More than 800 spectral lines could be classified with help of these levels. Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2014-50025-7

  14. 1H NMR spectra of N-methyl-4-tolyl-1-(4-bromonaphthylamine and N-phenyl-1-(4-bromonaphthylamine: a combined experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Sergiy I. Okovytyy

    2014-03-01

    Full Text Available Theoretical investigations of the conformational properties and 1H NMR chemical shifts for N-methyl-4-tolyl-1-(4-bromonaphthylamine and N-phenyl-1-(4-bromonaphthylamine are reported. The calculations were performed at the DFT level (PBE1PBE functional using magnetically consistent 6-31G## and STO##-3Gmag basis sets. Conformational properties of the amines were studied using potential energy surface scanning. Chemical shifts were calculated using the GIAO and CSGT methods and averaged in proportion to the population of the corresponding conformations. Solvent effects (CDCl3 were accounted via PCM method. The obtained results allowed to assign the 1H NMR signals for the naphthalene moiety, which could not be done based on the experimental data alone.

  15. Power Quality Experimental Analysis on Rural Home Grid-Connected PV Systems

    Directory of Open Access Journals (Sweden)

    Rita Jorge Cerqueira Pinto

    2015-01-01

    Full Text Available Microgeneration is the small-scale generation of heat or electric power or both, by individuals or buildings to meet their own needs. Recently, microgeneration is being regarded as a means to decentralize the power production of renewable energies, reducing the impacts on the grid caused by unexpected energy demands. Given the increase in microgeneration facilities, determining the quantity of energy produced and the power quality assumes growing importance in low, medium, or high voltage facilities. This paper presents a power quality analysis of two different facilities with photovoltaic generation localized in a rural area of Portugal, describing the voltage and frequency behaviour, the harmonic contents, and the total harmonic distortion. Statistical data are presented regarding the number of voltage events and occurrence of dips and swells in both facilities as a percentage of rated voltage. We conclude that some PV systems can severely affect voltage quality, forcing the grid to work at and even above the maximum voltage standard limit.

  16. Biomass-powered Solid Oxide Fuel Cells : Experimental and Modeling Studies for System Integrations

    NARCIS (Netherlands)

    Liu, M.

    2013-01-01

    Biomass is a sustainable energy source which, through thermo-chemical processes of biomass gasification, is able to be converted from a solid biomass fuel into a gas mixture, known as syngas or biosyngas. A solid oxide fuel cell (SOFC) is a power generation device that directly converts the chemical

  17. Two-slope soft X-ray spectra observed in experiments on electron cyclotron resonance plasma heating in the L-2M stellarator

    Science.gov (United States)

    Meshcheryakov, A. I.; Vafin, I. Yu.; Grishina, I. A.; Letunov, A. A.; Tereshchenko, M. A.

    2017-06-01

    In experiments on the generation and electron cyclotron resonance heating (ECRH) of plasma in the L-2M stellarator, non-Maxwellian two-slope soft X-ray (SXR) spectra were observed. The temperatures of the thermal and epithermal components of the spectra were measured as functions of the heating power and plasma density. A hypothesis based on the experimental results is suggested to explain the formation mechanism of two-slope SXR spectra in the ECRH experiments at the L-2M stellarator. The measured SXR spectra are compared with the results of numerical simulations.

  18. The Power of High-Throughput Experimentation in Homogeneous Catalysis Research for Fine Chemicals

    NARCIS (Netherlands)

    Vries, Johannes G. de; Vries, André H.M. de

    2003-01-01

    The use of high-throughput experimentation (HTE) in homogeneous catalysis research for the production of fine chemicals is an important breakthrough. Whereas in the past stoichiometric chemistry was often preferred because of time-to-market constraints, HTE allows catalytic solutions to be found

  19. PSpice Modeling Platform for SiC Power MOSFET Modules with Extensive Experimental Validation

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Iannuzzo, Francesco; Nawaz, Muhammad

    2016-01-01

    The aim of this work is to present a PSpice implementation for a well-established and compact physics-based SiC MOSFET model, including a fast, experimental-based parameter extraction procedure in a MATLAB GUI environment. The model, originally meant for single-die devices, has been used...

  20. Monte Carlo simulation - a powerful tool to support experimental activities in structure reliability

    Energy Technology Data Exchange (ETDEWEB)

    Yuritzinn, T. [CEA Saclay, Dept. de Mecanique et de Technologie (DRN/DMT/SEMT/LISN), 91 - Gif-sur-Yvette (France); Chapuliot, S. [CEA Saclay, Dept. Modelisation de Systemes et Structures (DM2S/SEMT), 91 - Gif sur Yvette (France); Eid, M. [CEA Saclay, Dept. de Mecanique et de Technologie (DRN/DMT/SERMA/LCA), 91 - Gif-sur-Yvette (France); Masson, R.; Dahl, A.; Moinereau, D. [Electricite de France (EDF), 75 - Paris (France)

    2003-07-01

    Monte-Carlo Simulation (MCS) can have different uses in supporting structure reliability investigations and assessments. In this paper we focus our interest on the use of MCS as a numerical tool to support the fitting of the experimental data related to toughness experiments. (authors)

  1. Power-law Schell-model sources

    Science.gov (United States)

    Hyde, Milo W.

    2017-11-01

    A new type of Schell-model source is developed that has a spectral degree of coherence, or spatial power spectrum, which is described by a power-law function. These power-law sources generally produce cusped, or peaked far-zone spectral density patterns making them potentially useful in directed energy applications. The spectral degrees of coherence, spatial power spectra, and spatial coherence radii for power-law sources are derived and discussed. Two power-law sources are then synthesized in the laboratory using a liquid crystal spatial light modulator. The experimental spectral densities are compared to the corresponding theoretical predictions to serve as a proof of concept.

  2. Experimentality: The friendly face of power? The interactive new media as tools of discretionary governance and risk management

    Directory of Open Access Journals (Sweden)

    Wolf Heydebrand

    2013-10-01

    Full Text Available The interactive new media (INM are a powerful information technology (IT with contradictory consequences for the nature of work, creativity, and innovation. Digital interactivity shortens both time and distance within and across global networks. It reduces labor time and transaction costs, eases the shift from manual to mental labor, and raises efficiency, productivity, and profits. It facilitates quick responses to changing conditions and new opportunities, and it encourages experimentation, risk taking, discovery, and innovation. IT and INM constitute the technical infrastructure of advanced business and consulting services like advertising, management consulting, and accounting. They are popular components of the globalizing culture industry. But INM are also instruments of discretionary governance and neoliberal governmentality. They have an unaccountable influence on financial, actuarial, cybernetic and ideological forms of power, and they serve to extend the mechanisms of indirect and anonymous social control into everyday life. The INM are widely adopted for purposes of discretionary governance and risk management, but tend to escape autonomous social and democratic regulation. The paper examines the effects of INM on small project teams as well as on aspects of neoliberal experimentality such as informalism and flexibility at work, the hacker work ethic, social networking, and techno-libertarianism. The conclusion reconsiders the intrinsic tension between neoliberal experimentality and governmentality.

  3. Microwave Saturation of Complex EPR Spectra and Free Radicals of Burnt Skin Treated with Apitherapeutic Agent

    Directory of Open Access Journals (Sweden)

    Pawel Olczyk

    2013-01-01

    Full Text Available The effect of microwave power on the complex electron paramagnetic resonance spectra of the burn matrix after the therapy with propolis was examined. The spectra were measured with microwaves in the range of 2.2–79 mW. Three groups of free radicals were found in the damaged skin samples. Their spectral lines evolve differently with the microwave power. In order to detect these free radical groups, the lineshape of the spectra was numerically analysed. The spectra were a superposition of three component lines. The best fit was obtained for the deconvolution of the experimental spectra into one Gauss and two Lorentz lines. The microwave power changes also the lineshape of the spectra of thermally injured skin treated with the conventional agent—silver sulphadiazine. The spectral changes were different for propolis and for silver sulphadiazine. The number of individual groups of free radicals in the wound bed after implementation of these two substances is not equal. It may be explained by a higher activity of propolis than of silver sulphadiazine as therapeutic agents.

  4. On the applicability of Arrhenius plot methods to determine surface energetic heterogeneity of adsorbents and catalysts surfaces from experimental TPD spectra.

    Science.gov (United States)

    Rudzinski, W; Borowiecki, T; Panczyk, T; Dominko, A

    2000-01-01

    Recovering adsorption energy distribution from experimental data belongs to most difficult problems of adsorption science. In the case when thermodesorption data are used as a source of information, that difficult problem is overcome by the common use of the Arrhenius plot methods. So, we decided to carry out an extensive model investigation to show, how reliable information concerning the surface energetic heterogeneity is obtained by using the Arrhenius plot methods. Like in our previous publications we have used the Statistical Rate Theory of Interfacial Transport to describe the adsorption/desorption kinetics. Our model investigations showed, that the Arrhenius plot methods, cannot provide reliable information about the surface energetic heterogeneity. Moreover, for strongly heterogeneous surfaces a linear relationship exists between the logarithm of the pre-exponential constant and the adsorption energy, for certain adsorption coverages. That kind of compensation effect has, so far, been ascribed to interactions between the adsorbed molecules. The failure of the popular Arrhenius plot method puts, as an urgent agenda, the development of reliable methods for recovering adsorption energy distribution from the thermodesorption data.

  5. Machine learning molecular dynamics for the simulation of infrared spectra.

    Science.gov (United States)

    Gastegger, Michael; Behler, Jörg; Marquetand, Philipp

    2017-10-01

    Machine learning has emerged as an invaluable tool in many research areas. In the present work, we harness this power to predict highly accurate molecular infrared spectra with unprecedented computational efficiency. To account for vibrational anharmonic and dynamical effects - typically neglected by conventional quantum chemistry approaches - we base our machine learning strategy on ab initio molecular dynamics simulations. While these simulations are usually extremely time consuming even for small molecules, we overcome these limitations by leveraging the power of a variety of machine learning techniques, not only accelerating simulations by several orders of magnitude, but also greatly extending the size of systems that can be treated. To this end, we develop a molecular dipole moment model based on environment dependent neural network charges and combine it with the neural network potential approach of Behler and Parrinello. Contrary to the prevalent big data philosophy, we are able to obtain very accurate machine learning models for the prediction of infrared spectra based on only a few hundreds of electronic structure reference points. This is made possible through the use of molecular forces during neural network potential training and the introduction of a fully automated sampling scheme. We demonstrate the power of our machine learning approach by applying it to model the infrared spectra of a methanol molecule, n -alkanes containing up to 200 atoms and the protonated alanine tripeptide, which at the same time represents the first application of machine learning techniques to simulate the dynamics of a peptide. In all of these case studies we find an excellent agreement between the infrared spectra predicted via machine learning models and the respective theoretical and experimental spectra.

  6. Experimental investigation on the spray characteristics of power-law fluid in a swirl injector

    Science.gov (United States)

    Bai, Fuqiang; Chang, Qing; Chen, Shixing; Guo, Jinpeng; Jiao, Kui; Du, Qing

    2017-06-01

    High-speed photography and 3D phase Doppler methods are used to obtain the swirl jet images, 3D velocities and size distribution of different droplets (including deionized water and two kinds of power-law fluid). For the power-law fluids, a short circular jet is formed after the nozzle exit at low pressure. Along the X direction, the distributions of axial velocity w and Sauter mean diameter (SMD) are symmetrical and increase from the center to both sides. The effect of injection pressure on the radial velocity u is not obvious. Along the Z axis, the absolute value of 3D velocities decreases to some extent with droplets moving downstream. The SMD decreases apparently with the increment of the distance along the Z axis at 1.0 MPa.

  7. "Kicking Up Some Dust": An Experimental Investigation Relating Lunar Dust Erosive Wear to Solar Power Loss

    Science.gov (United States)

    Mpagazehe, Jeremiah N.; Street, Kenneth W., Jr.; Delgado, Irebert R.; Higgs, C. Fred, III

    2013-01-01

    The exhaust from retrograde rockets fired by spacecraft landing on the Moon can accelerate lunar dust particles to high velocities. Information obtained from NASA's Apollo 12 mission confirmed that these high-speed dust particles can erode nearby structures. This erosive wear damage can affect the performance of optical components such as solar concentrators. Solar concentrators are objects which collect sunlight over large areas and focus the light into smaller areas for purposes such as heating and energy production. In this work, laboratory-scale solar concentrators were constructed and subjected to erosive wear by the JSC-1AF lunar dust simulant. The concentrators were focused on a photovoltaic cell and the degradation in electrical power due to the erosive wear was measured. It was observed that even moderate exposure to erosive wear from lunar dust simulant resulted in a 40 percent reduction in power production from the solar concentrators.

  8. PV System with Maximum Power Point Tracking: Modeling, Simulation and Experimental Results

    OpenAIRE

    PEREIRA, R. J.; Melício, R.; Mendes, V.M.F.; Joyce, A.

    2014-01-01

    This paper focuses on the five parameters modeling, consisting on a current controlled generator, single-diode, a shunt and series resistances. Also, a simulation, identification of the parameters for a photovoltaic system and the maximum power point tracking based on VP„g„g is presented. The identification of parameters and the performance of the equivalent circuit model for a solar module simulation are validated by data measured on the photovoltaic modules.

  9. Experimental Investigation Of An ORC System For A Micro-Solar Power Plant

    OpenAIRE

    Dickes, Rémi; Dumont, Olivier; Declaye, Sébastien; Quoilin, Sylvain; Bell, Ian; Lemort, Vincent

    2014-01-01

    Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed, solar energy, and more specifically CSP (Concentrated Solar Power) systems are expected to play a key role to supply centralized loads and off-grid areas in the medium-term. Major performance improvements can be achieved by implementing advanced control strategies accounting for the transie...

  10. Experimental Verification and Integration of a Next Generation Smart Power Management System

    Science.gov (United States)

    Clemmer, Tavis B.

    With the increase in energy demand by the residential community in this country and the diminishing fossil fuel resources being used for electric energy production there is a need for a system to efficiently manage power within a residence. The Smart Green Power Node (SGPN) is a next generation energy management system that automates on-site energy production, storage, consumption, and grid usage to yield the most savings for both the utility and the consumer. Such a system automatically manages on-site distributed generation sources such as a PhotoVoltaic (PV) input and battery storage to curtail grid energy usage when the price is high. The SGPN high level control features an advanced modular algorithm that incorporates weather data for projected PV generation, battery health monitoring algorithms, user preferences for load prioritization within the home in case of an outage, Time of Use (ToU) grid power pricing, and status of on-site resources to intelligently schedule and manage power flow between the grid, loads, and the on-site resources. The SGPN has a scalable, modular architecture such that it can be customized for user specific applications. This drove the topology for the SGPN which connects on-site resources at a low voltage DC microbus; a two stage bi-directional inverter/rectifier then couples the AC load and residential grid connect to on-site generation. The SGPN has been designed, built, and is undergoing testing. Hardware test results obtained are consistent with the design goals set and indicate that the SGPN is a viable system with recommended changes and future work.

  11. Development and Experimental Studies of a Small-scaled Solar-powered Sago Plant Dehydrator

    OpenAIRE

    A. Pendita; Lim, P.Y.; H. V. H. Junis

    2014-01-01

    Sago is an important agricultural commodity of the largest state in Malaysia, Sarawak. This paper presents a small-scaled solar-powered sago dehydrator with temperature sensing and monitoring unit. The main focus is to provide a feasible solution for sago farmers or producers who live in isolated remote areas. The dehydrator system is controlled by a microcontroller PIC16F877A. The electrical circuit of the dehydrator allows the user to programmed desired time setting and the controller will ...

  12. Design of an Advanced Modular Automated Evaluation System for Experimental High Power SGTOS

    Science.gov (United States)

    2013-06-01

    HIGH POWER SGTOS Shelby Lacouture, Kevin Lawson, Stephen Bayne , Michael Giesselmann, Heather O’Brien 1 , Aderinto Ogunniyi 1 , Charles J...hopefully aid in understanding of why failure occurred, and lead to improvements in device durability. VI. REFERENCES [1] Lacouture, S.; Bayne ...Conference (PPC), 2011 IEEE , vol., no., pp.1474-1476, 19-23 June 2011. [2] Lacouture, S.; Bayne , S.B.; Giesselmann, M.G.; Lawson, K.; O’Brien, H

  13. An Experimental Analysis of Price Formation on the Polish Power Exchange

    Directory of Open Access Journals (Sweden)

    Drabik Ewa

    2015-12-01

    Full Text Available The Polish energy market gained its competitive character in late 1990s. At that time in majority of European countries a new law was enacted (in Poland – in 1987, which enabled the creation of internal energy markets. The Polish Power Exchange has been functioning since the end of 1999. However, from the very onset it has constituted a vital component of under grounding liberalization of electricity market. Since it was created the Polish Power Exchange has served as a market mechanism for setting objective energy market price. Support and control of the Polish Financial Supervision Authority guarantee the security of concluded transactions. The spot energy market was created as the first one and has functioned according to the rule of the double auction. The model of Sadrieh will be used for the description of the auction rules applied to the spot energy trade on the Polish Power Exchange. Furthermore, an algorithm on the basis of which it is possible to forecast transaction prices is presented. The effectiveness of this algorithm will be compared with other traditional methods of forecasting transaction prices.

  14. An Experimental Study of Laboratory Hybrid Power System with the Hydrogen Technologies

    Directory of Open Access Journals (Sweden)

    Daniel Minarik

    2014-01-01

    Full Text Available This paper presents very small laboratory hybrid photovoltaic-hydrogen power system. The system was primarily assembled to verify the operability of the control algorithms and practical deployment of available commercial hydrogen technologies that are directly usable for storage of electricity produced from renewable energy sources in a small island system. This energetic system was installed and tested in Laboratory of fuel cells that is located in the university campus of VSB-Technical University of Ostrava. The energetic system consists of several basic components: a photovoltaic field, accumulators bank, water commercial electrolyzer and compact fuel cell system. The weather conditions recorded in two different weeks as model weather and solar conditions are used as case studies to test the energetic system and the results for two different cases are compared each other. The results show and illustrate selected behaviour curves of the power system and also average energy storage efficiency for accumulation subsystem based on hydrogen technologies or at the energetic system embedded components. On the basis of real measurement and its evaluation the ideal parameters of the photovoltaic field were calculated as well as the hydrogen technologies for supposed purpose and the power requirements.

  15. Experimental Process Identification for Industrial Water De-carbonization in Power Plants

    Directory of Open Access Journals (Sweden)

    MSc. Lutfi Bina

    2013-12-01

    Full Text Available Water Treatment Plant (or WTP is the most important part of the Power Plant, because it produces vital-water it needs for steam production. Power Plants are the biggest air, ground and groundwater pollutants. Bad water quality directly impacts machine duration. Polluted water from Water Treatment Plant has a negative effect on people, flora and fauna, thus better waste management programs should be put in place to eliminate this problem.  In this paper we are going to present the de-carbonization process of raw water as a part of water treatment plant, within coal fired power plants. De-carbonizing water is a time consuming process. We are going to present an advanced method for process identification with big time delay. The results are compared and one of the most appropriate methods is selected as identification method for this process. Further research and possibilities in this area are going to be presented by the end of the paper. Progress in identifying the process by which we work in this paper may serve as a new way to identify highly nonlinear processes. The used algorithm for identification of the process that is outlined in this paper can be applied, and it will be the basis for the creation of the software for the application of microcomputer techniques. Here we are applying the relevant software which can be applied in the form of programming packages for identification. This has to do with passive identification methods.

  16. Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol.

    Science.gov (United States)

    Demircioğlu, Zeynep; Albayrak, Çiğdem; Büyükgüngör, Orhan

    2014-07-15

    A suitable single crystal of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol, formulated as C15H15N1O2, reveals that the structure is adopted to its E configuration about the azomethine C=N double bond. The compound adopts a enol-imine tautomeric form with a strong intramolecular O-H⋯N hydrogen bond. The single crystal X-ray diffraction analysis at 296K crystallizes in the monoclinic space group P21/c with a = 13.4791(11) Å, b = 6.8251(3) Å, c = 18.3561(15) Å, α = 90°, β = 129.296(5)°, γ = 90° and Z = 4. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR and UV-vis spectrometry. Optimized molecular structure and harmonic vibrational frequencies have been investigated by DFT/B3LYP method with 6-31G(d,p) basis set. Stability of the molecule, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed by TD-DFT method and the relocation of the electron density were determined. The energetic behavior of the title compound has been examined in solvent media using polarizable continuum model (PCM). Molecular electrostatic potential (MEP), Mulliken population method and natural population analysis (NPA) have been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analysis have been performed from the optimized geometry. An ionization potential (I), electron affinity (A), electrophilicity index (ω), chemical potential (μ), electronegativity (χ), hardness (η), and softness (S), have been investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. An Analytical and Experimental Investigation of Average Laser Power and Angular Scanning Speed Effects on Laser Tube Bending Process

    Directory of Open Access Journals (Sweden)

    Imhan Khalil Ibraheem

    2017-01-01

    Full Text Available Laser tube bending is a new technique of laser material forming to produce a complex and accurate shape due to its flexibility and high controllability. Moreover, the defects during conventional tube forming such as thinning, wrinkling, spring back and ovalization can be avoided in laser tube bending process, because there is no external force used. In this paper an analytical investigation has been conducted to analyses the effects of average laser power and laser scanning speed on laser tube bending process, the analytical results have been verified experimentally. The model used in this study is in the same trend of the experiment. The results show that the bending angle increased with the increasing of average laser power and decreased with the increasing of angular scanning speed.

  18. Analysis and experimental study of wireless power transfer with HTS coil and copper coil as the intermediate resonators system

    Science.gov (United States)

    Wang, Xiufang; Nie, Xinyi; Liang, Yilang; Lu, Falong; Yan, Zhongming; Wang, Yu

    2017-01-01

    Intermediate resonator (repeater) between transmitter and receiver can significantly increase the distance of wireless power transfer (WPT) and the efficiency of wireless power transfer. The wireless power transfer via strongly coupled magnetic resonances with an high temperature superconducting (HTS) coil and copper coil as intermediate resonators was presented in this paper. The electromagnetic experiment system under different conditions with different repeating coils were simulated by finite element software. The spatial distribution patterns of magnetic induction intensity at different distances were plotted. In this paper, we examined transfer characteristics with HTS repeating coil and copper repeating coil at 77 K and 300 K, respectively. Simulation and experimental results show that HTS and copper repeating coil can effectively enhance the space magnetic induction intensity, which has significant effect on improving the transmission efficiency and lengthening transmission distance. We found that the efficiency and the distance of wireless power transfer system with an HTS coil as repeater is much higher by using of copper coil as repeater.

  19. Analysis and experimental study of wireless power transfer with HTS coil and copper coil as the intermediate resonators system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiufang [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Physics and Technology, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Nie, Xinyi [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Liang, Yilang [School of Physics and Technology, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Lu, Falong [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Yan, Zhongming, E-mail: wangxiufanghappy@163.com [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Wang, Yu [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

    2017-01-15

    Highlights: • We investigated a kind of system architecture with three coils which the repeater is copper coil or HTS coil. • We simulated the different repeater system and obtained the magnetic field distribution at different distance. • We used helical coil instead of pancake coil which does not use capacitors. • HTS intermediate coil has significant effect on improving the transmission efficiency and lengthening transmission distance than copper intermediate coil. - Abstract: Intermediate resonator (repeater) between transmitter and receiver can significantly increase the distance of wireless power transfer (WPT) and the efficiency of wireless power transfer. The wireless power transfer via strongly coupled magnetic resonances with an high temperature superconducting (HTS) coil and copper coil as intermediate resonators was presented in this paper. The electromagnetic experiment system under different conditions with different repeating coils were simulated by finite element software. The spatial distribution patterns of magnetic induction intensity at different distances were plotted. In this paper, we examined transfer characteristics with HTS repeating coil and copper repeating coil at 77 K and 300 K, respectively. Simulation and experimental results show that HTS and copper repeating coil can effectively enhance the space magnetic induction intensity, which has significant effect on improving the transmission efficiency and lengthening transmission distance. We found that the efficiency and the distance of wireless power transfer system with an HTS coil as repeater is much higher by using of copper coil as repeater.

  20. Experimental Study and Optimization of Thermoelectricity-Driven Autonomous Sensors for the Chimney of a Biomass Power Plant

    Science.gov (United States)

    Rodríguez, A.; Astrain, D.; Martínez, A.; Aranguren, P.

    2014-06-01

    In the work discussed in this paper a thermoelectric generator was developed to harness waste heat from the exhaust gas of a boiler in a biomass power plant and thus generate electric power to operate a flowmeter installed in the chimney, to make it autonomous. The main objective was to conduct an experimental study to optimize a previous design obtained after computational work based on a simulation model for thermoelectric generators. First, several places inside and outside the chimney were considered as sites for the thermoelectricity-driven autonomous sensor. Second, the thermoelectric generator was built and tested to assess the effect of the cold-side heat exchanger on the electric power, power consumption by the flowmeter, and transmission frequency. These tests provided the best configuration for the heat exchanger, which met the transmission requirements for different working conditions. The final design is able to transmit every second and requires neither batteries nor electric wires. It is a promising application in the field of thermoelectric generation.

  1. Results of experimental research of the tribological characteristics of oils from engines and power transmitters of vehicles

    Directory of Open Access Journals (Sweden)

    Sreten R. Perić

    2011-10-01

    Full Text Available Nowadays, a special attention is focused on the development of modern devices and methods for monitoring condition changes of tribomehanical characteristics in systems. There are different physical and chemical methods and tribology methods for tribomehanical system diagnosis. Experience in technical systems exploitation showed that the most effective failure prognosis is based on particles created as a result of wear. The analysis of oil samples containing particles-products of wear, enables the evaluation of system tribology conditions in different phases of system exploitation. The paper presents the tribological tests in the analysis of oils used for the assessment of its condition. The paper also deals with the results of the experimental research of tribological characteristics of motor and power transmitter oils sampled from engines and power transmitters of the Mercedes O 345, PUCH 300GD and PINZGAUER 710M vehicles in exploitation. The investigations showed that there is a change of tribological characteristics of lubrication oils in the vehicle engine and power transmitters. These changes are in a direct dependence of the state of all elements of the tribomechanical engine and power transmitters system, and they depend on their functional characteristics. The conclusion is based on the realized testing.

  2. Modification of the high latitude ionosphere F region by X-mode powerful HF radio waves: Experimental results from multi-instrument diagnostics

    Science.gov (United States)

    Blagoveshchenskaya, N. F.; Borisova, T. D.; Yeoman, T. K.; Häggström, I.; Kalishin, A. S.

    2015-12-01

    We present experimental results concentrating on a variety of phenomena in the high latitude ionosphere F2 layer induced by an extraordinary (X-mode) HF pump wave at high heater frequencies (fH=6.2-8.0 MHz), depending on the pump frequency proximity to the ordinary and extraordinary mode critical frequencies, foF2 and fxF2. The experiments were carried out at the EISCAT HF heating facility with an effective radiated power of 450-650 MW in October 2012 and October-November 2013. Their distinctive feature is a wide diapason of critical frequency changes, when the fH/foF2 ratio was varied through a wide range from 0.9 to 1.35. It provides both a proper comparison of X-mode HF-induced phenomena excited under different ratios of fH/foF2 and an estimation of the frequency range above foF2 in which such X-mode phenomena are still possible. It was shown that the HF-enhanced ion and plasma lines are excited above foF2 when the HF pump frequency is lying in range between the foF2 and fxF2, foF2≤fH≤fxF2, whereas small-scale field-aligned irregularities continued to be generated even when fH exceeded fxF2 by up to 1 MHz and an X-polarized pump wave cannot be reflected from the ionosphere. Another parameter of importance is the magnetic zenith effect (HF beam/radar angle direction) which is typical for X-mode phenomena under fH/foF2 >1 as well as fH/foF2 ≤1. We have shown for the first time that an X-mode HF pump wave is able to generate strong narrowband spectral components in the SEE spectra (within 1 kHz of pump frequency) in the ionosphere F region, which were recorded at distance of 1200 km from the HF heating facility. The observed spectral lines can be associated with the ion acoustic, electrostatic ion cyclotron, and electrostatic ion cyclotron harmonic waves (otherwise known as neutralized ion Bernstein waves). The comparison between the O- and X-mode SEE spectra recorded at distance far from HF heating facility clearly demonstrated that variety of the narrowband

  3. Experimental Clocking of Nanomagnets with Strain for Ultralow Power Boolean Logic.

    Science.gov (United States)

    D'Souza, Noel; Salehi Fashami, Mohammad; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2016-02-10

    Nanomagnetic implementations of Boolean logic have attracted attention because of their nonvolatility and the potential for unprecedented overall energy-efficiency. Unfortunately, the large dissipative losses that occur when nanomagnets are switched with a magnetic field or spin-transfer-torque severely compromise the energy-efficiency. Recently, there have been experimental reports of utilizing the Spin Hall effect for switching magnets, and theoretical proposals for strain induced switching of single-domain magnetostrictive nanomagnets, that might reduce the dissipative losses significantly. Here, we experimentally demonstrate, for the first time that strain-induced switching of single-domain magnetostrictive nanomagnets of lateral dimensions ∼200 nm fabricated on a piezoelectric substrate can implement a nanomagnetic Boolean NOT gate and steer bit information unidirectionally in dipole-coupled nanomagnet chains. On the basis of the experimental results with bulk PMN-PT substrates, we estimate that the energy dissipation for logic operations in a reasonably scaled system using thin films will be a mere ∼1 aJ/bit.

  4. Transformation of spectra of refraction index fluctuations in axisymmetric supersonic jet with the increase in the distance from the nozzle

    Directory of Open Access Journals (Sweden)

    Marakasov Dmitrii

    2017-01-01

    Full Text Available In this paper the results of reconstruction of the radial dependence of refraction index fluctuations spectra in axisymmetric supersonic jet from laser transillumination data are presented. The reconstruction algorithm uses experimental spectra of laser radiation, received behind the jet, and the distribution of time-averaged axial air velocity within the jet. Laser transillumination experiments were performed on the Vertical Jet Unit of ITAM SB RAS (Novosibirsk, Russia. Reconstruction results show the refraction index spectra obey the power-law model, with power index different from that of the Kolmogorov turbulence model (−11/3. Within the first two barrels of the jet the power index is changing from ~−1 near the nozzle to ~−2.7 near the second Mach disk. Also some variations of power index and amplitude coefficient with the distance from the jet axis are found.

  5. An oscillograms processing algorithm of a high power transformer on the basis of experimental data

    Science.gov (United States)

    Vasileva, O. V.; Budko, A. A.; Lavrinovich, A. V.

    2016-04-01

    The paper presents the studies on digital processing of oscillograms of the power transformer operation allowing determining the state of its windings of different types and degrees of damage. The study was carried out according to the authors' own methods using the Fourier analysis and the developed program based on the following application software packages: MathCAD and Lab View. The efficiency of the algorithm was demonstrated by the example of the waveform non-defective and defective transformers on the basis of the method of nanosecond pulses.

  6. Experimental and theoretical analysis of an optical current sensor for high power systems

    Science.gov (United States)

    Brigida, A. C. S.; Nascimento, I. M.; Mendonça, S.; Costa, J. C. W. A.; Martinez, M. A. G.; Baptista, J. M.; Jorge, P. A. S.

    2013-03-01

    A magneto-optical sensor, using a dual quadrature polarimetric processing scheme, was evaluated for current metering and protection applications in high voltage lines. Sensor calibration and resolution were obtained in different operational conditions using illumination in the 1550-nm band. Results obtained indicated the feasibility of interrogating such sensor via the optical ground wire (OPGW) link installed in standard high power grids. The polarimetric bulk optical current sensor also was theoretically studied, and the effects of different sources of error considering practical deployment were evaluated. In particular, the interference from external magnetic fields in a tree-phase system was analyzed.

  7. Experimental Testing of a Metamaterial Slow Wave Structure for High-Power Microwave Generation

    Science.gov (United States)

    Shipman, K.; Prasad, S.; Andreev, D.; Fisher, D. M.; Reass, D. B.; Schamiloglu, E.; Gilmore, M.

    2017-10-01

    A high-power L band source has been developed using a metamaterial (MTM) to produce a double negative slow wave structure (SWS) for interaction with an electron beam. The beam is generated by a 700 kV, 6 kA short pulse (10 ns) accelerator. The design of the SWS consists of a cylindrical waveguide, loaded with alternating split-rings that are arrayed axially down the waveguide. The beam is guided down the center of the rings, where electrons interact with the MTM-SWS producing radiation. Power is extracted axially via a circular waveguide, and radiated by a horn antenna. Microwaves are characterized by an external detector placed in a waveguide. Mode characterization is performed using a neon bulb array. The bulbs are lit by the electric field, resulting in an excitation pattern that resembles the field pattern. This is imaged using an SLR camera. The MTM structure has electrically small features so breakdown is a concern. In addition to high speed cameras, a fiber-optic-fed, sub-ns photomultiplier tube array diagnostic has been developed and used to characterize breakdown light. Work supported by the Air Force Office of Scientific Research, MURI Grant FA9550-12-1-0489.

  8. Experimental estimation of mismatch uncertainty in radio – frequency power and attenuation measurements

    Directory of Open Access Journals (Sweden)

    Patel Kamlesh

    2015-01-01

    Full Text Available In this paper, the effects of the input quantity representations in linear and complex forms are analyzed to estimate mismatch uncertainty separately for one-port and two-port components. The mismatch uncertainties in power and attenuation measurements are evaluated for direct, ratio and substitution techniques with the use of a vector network analyzer system in the range of 1 to 18 GHz. The estimated mismatch uncertainties were compared for the same device under test and these values have verified that their evaluation is dependent on the representations of input quantities. In power measurements, the mismatch uncertainty is reduced when evaluating from the voltage standing wave ratio or reflection coefficient magnitudes in comparison to the complex reflection coefficients. The mismatch uncertainty in the attenuation measurements, are found higher and linearly increasing while estimating from the linear magnitude values than those from the S-parameters of the attenuator. Thus in practice, the mismatch uncertainty is estimated more accurately using the quantities measured in the same representations as of measuring quantity.

  9. Theoretical and Experimental Investigations of the Potential of Osmotic Energy for Power Production

    Directory of Open Access Journals (Sweden)

    Adel O. Sharif

    2014-08-01

    Full Text Available This paper presents a study on the potential of osmotic energy for power production. The study includes both pilot plant testing and theoretical modelling as well as cost estimation. A projected cost of £30/MWh of clean electricity could be achieved by using a Hydro-Osmotic Power (HOP plant if a suitable membrane is used and the osmotic potential difference between the two solutions is greater than 25 bar; a condition that can be readily found in many sites around the world. Results have shown that the membrane system accounts for 50%–80% of the HOP plant cost depending on the salinity difference level. Thus, further development in membrane technology and identifying suitable membranes would have a significant impact on the feasibility of the process and the route to market. As the membrane permeability determines the HOP process feasibility, this paper also describes the effect of the interaction between the fluid and the membrane on the system permeability. It has been shown that both the fluid physical properties as well as the membrane micro-structural parameters need to be considered if further development of the HOP process is to be achieved.

  10. Partial Stator Overlap in a Linear Generator for Wave Power: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Anna E. Frost

    2017-11-01

    Full Text Available This paper presents a study on how the power absorption and damping in a linear generator for wave energy conversion are affected by partial overlap between stator and translator. The theoretical study shows that the electrical power as well as the damping coefficient change quadratically with partial stator overlap, if inductance, friction and iron losses are assumed independent of partial stator overlap or can be neglected. Results from onshore experiments on a linear generator for wave energy conversion cannot reject the quadratic relationship. Measurements were done on the inductance of the linear generator and no dependence on partial stator overlap could be found. Simulations of the wave energy converter’s operation in high waves show that entirely neglecting partial stator overlap will overestimate the energy yield and underestimate the peak forces in the line between the buoy and the generator. The difference between assuming a linear relationship instead of a quadratic relationship is visible but small in the energy yield in the simulation. Since the theoretical deduction suggests a quadratic relationship, this is advisable to use during modeling. However, a linear assumption could be seen as an acceptable simplification when modeling since other relationships can be computationally costly.

  11. Marmote SDR: Experimental Platform for Low-Power Wireless Protocol Stack Research

    Directory of Open Access Journals (Sweden)

    Ákos Lédeczi

    2013-09-01

    Full Text Available Over the past decade, wireless sensor network research primarily relied on highly-integrated commercial off-the-shelf radio chips. The rigid silicon implementation of the radio stack restricted access to the lower layers; thus, research focused mainly on the medium access control (MAC layer and above. SRAM field-programmable gate array (FPGA-based software-defined radios (SDR, on the other hand, provide a flexible architecture to experiment with any and all layers of the radio stack, but usually require desktop computers and draw high currents that prohibit mobile or longer-term outdoor deployments. To address these issues, we have developed a modular flash FPGA-based wireless research platform, called Marmote SDR, that has computational resources comparable to those of SRAM FPGA-based radio platforms, but at a reduced power consumption, with duty cycling support. We discuss the design decisions underlying Marmote SDR and evaluate its power consumption. Furthermore, we present and evaluate an asynchronous and multiple access communication protocol specifically designed for data-gathering wireless sensor networks.

  12. DISSECTING THE POWER SOURCES OF LOW-LUMINOSITY EMISSION-LINE GALAXY NUCLEI VIA COMPARISON OF HST-STIS AND GROUND-BASED SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, Anca; Castillo, Christopher A. [Department of Physics and Astronomy, James Madison University, Harrisonburg, VA 22807 (United States); Shields, Joseph C. [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Barth, Aaron J. [Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2015-12-01

    Using a sample of ∼100 nearby line-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of Hα and neighboring emission lines at subarcsecond scales. We employ these data in a quantitative comparison of the nebular emission in Hubble Space Telescope (HST) and ground-based apertures, which offer an order-of-magnitude difference in contrast, and provide new statistical constraints on the degree to which transition objects and low-ionization nuclear emission-line regions (LINERs) are powered by an accreting black hole at ≲10 pc. We show that while the small-aperture observations clearly resolve the nebular emission, the aperture dependence in the line ratios is generally weak, and this can be explained by gradients in the density of the line-emitting gas: the higher densities in the more nuclear regions potentially flatten the excitation gradients, suppressing the forbidden emission. The transition objects show a threefold increase in the incidence of broad Hα emission in the high-resolution data, as well as the strongest density gradients, supporting the composite model for these systems as accreting sources surrounded by star-forming activity. The narrow-line LINERs appear to be the weaker counterparts of the Type 1 LINERs, where the low accretion rates cause the disappearance of the broad-line component. The enhanced sensitivity of the HST observations reveals a 30% increase in the incidence of accretion-powered systems at z ≈ 0. A comparison of the strength of the broad-line emission detected at different epochs implies potential broad-line variability on a decade-long timescale, with at least a factor of three in amplitude.

  13. Experimentally testing and assessing the predictive power of species assembly rules for tropical canopy ants

    Science.gov (United States)

    Fayle, Tom M; Eggleton, Paul; Manica, Andrea; Yusah, Kalsum M; Foster, William A

    2015-01-01

    Understanding how species assemble into communities is a key goal in ecology. However, assembly rules are rarely tested experimentally, and their ability to shape real communities is poorly known. We surveyed a diverse community of epiphyte-dwelling ants and found that similar-sized species co-occurred less often than expected. Laboratory experiments demonstrated that invasion was discouraged by the presence of similarly sized resident species. The size difference for which invasion was less likely was the same as that for which wild species exhibited reduced co-occurrence. Finally we explored whether our experimentally derived assembly rules could simulate realistic communities. Communities simulated using size-based species assembly exhibited diversities closer to wild communities than those simulated using size-independent assembly, with results being sensitive to the combination of rules employed. Hence, species segregation in the wild can be driven by competitive species assembly, and this process is sufficient to generate observed species abundance distributions for tropical epiphyte-dwelling ants. PMID:25622647

  14. Experimental research on blast power of fiber reinforced anti-hard target warhead

    Directory of Open Access Journals (Sweden)

    Bin Liang

    2017-06-01

    Full Text Available Fiber reinforced anti-hard-target warhead is a new-type sample munition, which is only designed based on theoretical analysis and numerical simulation in laboratory. This warhead consists of carbon composite casings and high explosive, which can greatly reduce the damage to objects outside the damage range. In order to evaluate its blasting damage effect on concrete target, the three types of charges were researched by means of experiment, which are bare charge, charge with carbon composite material shell and charge with steel shell. Experimental results show that the peak overpressure of charge with carbon fiber composite shell is higher than that of charge with steel shell, but is lower than that of bare charge in the case of the same TNT equivalence. No fragments and fragment effect exist for distant target under the condition of charge with carbon fiber composite shell. However, the experimental result of the charge with steel shell is completely contrary. According to the blast effect in the concrete target, the charge with carbon composite material shell is optimal in matched impedance and detonation propagation. Also, the effective energy produced by the detonation of explosive with carbon composite material shell is the largest.

  15. Design and experimental investigation of a decentralized GA-optimized neuro-fuzzy power system stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Talaat, Hossam E.A.; Abdennour, Adel; Al-Sulaiman, Abdulaziz A. [Electrical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421 (Saudi Arabia)

    2010-09-15

    The aim of this research is the design and implementation of a decentralized power system stabilizer (PSS) capable of performing well for a wide range of variations in system parameters and/or loading conditions. The framework of the design is based on Fuzzy Logic Control (FLC). In particular, the neuro-fuzzy control rules are derived from training three classical PSSs; each is tuned using GA so as to perform optimally at one operating point. The effectiveness and robustness of the designed stabilizer, after implementing it to the laboratory model, is investigated. The results of real-time implementation prove that the proposed PSS offers a superior performance in comparison with the conventional stabilizer. (author)

  16. The effect of ((-)-2-oxa-4-aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid (LY379268), an mGlu2/3 receptor agonist, on EEG power spectra and coherence in ketamine model of psychosis.

    Science.gov (United States)

    Fujáková, Michaela; Páleníček, Tomáš; Brunovský, Martin; Gorman, Ingmar; Tylš, Filip; Kubešová, Anna; Řípová, Daniela; Krajča, Vladimír; Horáček, Jiří

    2014-07-01

    In the present study we investigated the potential antipsychotic effects of the mGlu2/3 agonist LY379268 on changes in EEG power spectra and coherence in the ketamine model of psychosis. In order to use behaviorally active drug doses, experiments detecting changes in locomotor activity and sensorimotor gating were also conducted. In EEG experiments, adult male Wistar rats were injected with ketamine 30 mg/kg i.p. and LY379268 3 mg/kg i.p. Cortical EEG was recorded from twelve (2 × 6) electrodes placed homolaterally on each hemisphere. To avoid interference with the behavioral hyperactivity of ketamine challenge, the behavioral activity of animals was simultaneously registered at the time of recording. Subsequent power spectral and coherence analyses were assessed in epochs corresponding to behavioral inactivity. Analysis of segments with behavioral activity compared to inactivity was also performed. The effects of LY379268 3 mg/kg i.p. on the deficits in sensorimotor processing and on hyperlocomotion induced by ketamine were evaluated in the test of prepulse inhibition of acoustic startle reaction (PPI ASR) and in the open field. LY379268 reversed the ketamine-induced hyperlocomotion but had no effect on ketamine-induced PPI deficits. In EEG epochs corresponding to behavioral inactivity ketamine decreased the power in the delta band, induced a power increase in the high frequency bands and globally decreased EEG coherence. Pretreatment with the LY379268 completely reversed the ketamine-induced power increase in high frequency bands and had a partial effect on EEG coherence. LY379268 alone induced a decrease of beta, high beta and low-gamma power, and an increase in coherence in high frequency bands. Additional analysis revealed that behavioral activity increases power as well as coherence in most frequency bands. In conclusion, agonism of mGlu2/3 receptors was effective in reversing most of the changes induced by ketamine, however due to the lack of effectiveness

  17. The experimental study on the emanation power of a flow-through thoron source made from incandescent gas mantles.

    Science.gov (United States)

    Wang, Yunxiang; Zhang, Lei; Guo, Qiuju

    2017-12-18

    To improve the quality of the calibration of thoron concentration activity measurement, an experimental study on the emanation power of a flow-through thoron source based on incandescent gas mantles was carried out in this paper. The thoron activity concentrations of the outflowed air from the flow-through source were measured using RAD7, and the quantitative relationship between thoron concentrations and flowrates was studied through theoretical analysis, and the thoron emanation powers were obtained from the fitting of the relationship above. Results show that the thoron concentration decreased with the increasing flowrate in the gas path, and the thoron emanation powers of three batches of gas mantles obtained by fitting were 1.33% ± 0.17%, 0.77% ± 0.10% and 0.57% ± 0.07% respectively in low humidity condition. Those results were checked using the gamma spectroscopy method, and were consistent within the error range.

  18. Experimental results of a sheet-beam, high power, FEL amplifier with application to magnetic fusion research

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, S.; Destler, W.W.; Granatstein, V.L. [Univ. of Maryland, College Park, MD (United States)] [and others

    1995-12-31

    The experimental study of sheet-beam FELs as candidate millimeter-wave sources for heating magnetic fusion plasmas has achieved a major milestone. In a proof-of-principle, pulsed experiment, saturated FEL amplifier operation was achieved with 250 kW of output power at 86 GHz. Input microwave power was 1 kW, beam voltage was 450 kV and beam current was 17 A. The planar wiggler had a peak value of 3.8 kG, a period of 0.96 cm and was 71 cm long. The linear gain of 30 dB, saturated gain of 24 dB and saturated efficiency of 3% all are in good agreement with theoretical prediction. Follow-on work would include development of a thermionic sheet-beam electron-gun compatible with CW FEL operation, adding a section of tapered wiggler to increase the output power to levels in excess of 1 megawatt, and increasing the FEL frequency.

  19. Experimental results for the behavior of MSMAs subjected to loads seen in power harvesting applications and complex loads

    Science.gov (United States)

    Ciocanel, C.; Feigenbaum, H. P.

    2012-04-01

    The microstructure of magnetic shape memory alloys (MSMAs) is comprised of tetragonal martensite variants, each with their preferred internal magnetization orientation. In the presence of an external magnetic field, the martensite variants tend to reorient so that the preferred internal magnetization aligns with the external magnetic field. Thus MSMAs exhibit the shape memory effect when there is a magnetic field in the vicinity of a material point. Furthermore, the tetragonal nature of the martensite variants allows for a compressive stress to cause variant reorientation. This paper focuses on the experimental evaluation of MSMAs in power harvesting as well as on the response of the material under complex loading conditions. The experimental data reported here provides a basis for the evaluation of MSMAs suitability for applications other than the traditional actuation under a constant magnetic field. For power harvesting applications, consider an MSMA element subject to a large enough magnetic field so that all the variants begin in a field preferred state. Keeping the magnetic field constant and adding a variable compressive stress in a direction normal to that of the magnetic field, some or all of the martensitic variants may rotate into a stress preferred state. As the variants reorient, the internal magnetization vectors rotate, and the specimen's magnetization changes. The change in magnetization induces a current in a pick-up coil, resulting in an output voltage at its terminals according to Faraday's law of inductance. For other applications, the loads that an MSMA element is subject to may be different. Investigation into other potential loadings of an MSMA will give a better overall understanding of the magneto-mechanical behavior of MSMAs and perhaps highlight potential applications of these materials. Thus complex loads on MSMAs should be investigated experimentally and eventually modeled mathematically. For example, this work will study variable field

  20. Sistema experimental para el monitoreo de instalaciones de potencia haciendo uso de la Web; Experimental System for Power Installations Samples by Using the Web

    Directory of Open Access Journals (Sweden)

    Yoel R Rosales Hernández

    2011-02-01

    Full Text Available El artículo que se presenta describe una alternativa económica de sistema de adquisición de datos parael monitoreo de una instalación de potencia eléctrica trifásica. El sistema experimental está basado en unmicrocontrolador de Intel StrongARM SA-1110 de 32 bits con CPU RISC, una memoria flash de 16 Mbyte,una memoria SDRAM de 32 Mbyte y un controlador LAN Ethernet de 10/100 Mbps entre otros elementos.El mismo tiene instalado un sistema operativo Linux (kernel versión 2.4 y un servidor web thttpd. Através de un programa CGI se logra el muestreo, procesamiento y transmisión de la información recibidadesde un sistema trifásico de potencia y a partir de un protocolo HTTP se envía toda esta información aun grupo de clientes conectados a una red convencional de computadoras.  This work focuses on an economic alternative for developing a data acquisition system which monitors athree-phase power intalation. This experimental system is made up of an Intel StrongARM SA-1110 32-bitRISC microcontroller, a 16-Mbyte flash memory chip, a 32-MByte SDRAM chip, a 10/100 Mbps EthernetLAN controller with 10BASE-T, as well as other  hardware elements. The system has an embedded Linuxoperating system (kernel version 2.4, and a thttpd embedded web server. A CGI program was designed inorder to enable the sampling, processing and transmition of information received from the three-phasepower installation. To achieve this, a HTTP protocol was used in order to send all this information to agroup of clients connected to a conventional PC network.

  1. A Comparison of Cosmological Parameters Determined from CMB Temperature Power Spectra from the South Pole Telescope and the Planck Satellite

    Energy Technology Data Exchange (ETDEWEB)

    Aylor, K.; Hou, Z.; Knox, L.; Story, K. T.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H-M.; Chown, R.; Crawford, T. M.; Crites, A. T.; Haan, T. de; Dobbs, M. A.; Everett, W. B.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Keisler, R.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Omori, Y.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2017-11-20

    The Planck cosmic microwave background temperature data are best fit with a Lambda CDM model that mildly contradicts constraints from other cosmological probes. The South Pole Telescope (SPT) 2540 deg(2) SPT-SZ survey offers measurements on sub-degree angular scales (multipoles 650 <= l <= 2500) with sufficient precision to use as an independent check of the Planck data. Here we build on the recent joint analysis of the SPT-SZ and Planck data in Hou et al. by comparing Lambda CDM parameter estimates using the temperature power spectrum from both data sets in the SPT-SZ survey region. We also restrict the multipole range used in parameter fitting to focus on modes measured well by both SPT and Planck, thereby greatly reducing sample variance as a driver of parameter differences and creating a stringent test for systematic errors. We find no evidence of systematic errors from these tests. When we expand the maximum multipole of SPT data used, we see low-significance shifts in the angular scale of the sound horizon and the physical baryon and cold dark matter densities, with a resulting trend to higher Hubble constant. When we compare SPT and Planck data on the SPT-SZ sky patch to Planck full-sky data but keep the multipole range restricted, we find differences in the parameters n(s) and A(s)e(-2 tau). We perform further checks, investigating instrumental effects and modeling assumptions, and we find no evidence that the effects investigated are responsible for any of the parameter shifts. Taken together, these tests reveal no evidence for systematic errors in SPT or Planck data in the overlapping sky coverage and multipole range and at most weak evidence for a breakdown of Lambda CDM or systematic errors influencing either the Planck data outside the SPT-SZ survey area or the SPT data at l > 2000.

  2. Experimental study of properties of heavy concrete with bottom ash from power stations

    Directory of Open Access Journals (Sweden)

    Bondar Victor

    2017-01-01

    Full Text Available This article deals with the influence of cement quantity, plasticizing additives and compaction time on the strength and water consumption of concrete during its manufacturing using bottom ash from a thermal power station. The study was carried out using three factorial experiments. Variables varied on three levels. The obtained pattern functions characterize a relationship between strength, water consumption and variable factors. These factors include cement quantity, plasticize additives and compaction time. Compilation of Pareto effect charts allowed estimation of the significance of function indexes. Analysis of surface pattern function has revealed the optimal correlation between additive quantity and compaction time, cement quantity and additive quantity, cement quantity and compaction time. Compression strength of concrete was taken as the pattern in the pattern function. When analyzing the pattern function with water consumption as a pattern, optimal correlations between additive quantity and compaction time, cement quantity and additive quantity, cement quantity and compaction time were revealed. Application of STATISTICA 12 software has specified values of factors when the maximum strength is achieved. Correlations of components which have an impact on water consumption have been determined. The conclusions contain the quantitative findings of the study.

  3. Experimental study on surface properties of the PMMA used in high power spark gaps

    Directory of Open Access Journals (Sweden)

    Ruoyu Han

    2017-10-01

    Full Text Available This paper studies the surface properties of the Polymethylmethacrylate (PMMA insulator samples used in high power spark gaps. Experiments on surface morphology, surface profile, surface chemical composition and surface leakage current were performed. Metal particles ejected in tangent direction of discharge spots were researched on the sample surface. Three kinds of distinct bands were found on the surface after 1500 shots: colorless and transparent sinking band, black band, and grey powdered coating band. The thickness of the coating band was tens of microns and the maximum radial erosion rate was about 10 μm/C. Surface content analysis indicated that the powdered coating was a mixture of decomposed insulator material and electrode material oxides. In addition, leakage current significantly depended on water content in the chamber and presented an U-shape curve distribution along the insulator surface, in keeping with the amount of powdered coating due to shock waves. Possible reasons of the surface property changes were discussed. Electroconductive oxides of low valence states of Cu and W produced by the reactions between electrode materials and arc plasmas were considered to be the cause of dielectric performance degradation.

  4. Mercury Speciation in Coal-Fired Power Plant Flue Gas-Experimental Studies and Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Radisav Vidic; Joseph Flora; Eric Borguet

    2008-12-31

    The overall goal of the project was to obtain a fundamental understanding of the catalytic reactions that are promoted by solid surfaces present in coal combustion systems and develop a mathematical model that described key phenomena responsible for the fate of mercury in coal-combustion systems. This objective was achieved by carefully combining laboratory studies under realistic process conditions using simulated flue gas with mathematical modeling efforts. Laboratory-scale studies were performed to understand the fundamental aspects of chemical reactions between flue gas constituents and solid surfaces present in the fly ash and their impact on mercury speciation. Process models were developed to account for heterogeneous reactions because of the presence of fly ash as well as the deliberate addition of particles to promote Hg oxidation and adsorption. Quantum modeling was used to obtain estimates of the kinetics of heterogeneous reactions. Based on the initial findings of this study, additional work was performed to ascertain the potential of using inexpensive inorganic sorbents to control mercury emissions from coal-fired power plants without adverse impact on the salability fly ash, which is one of the major drawbacks of current control technologies based on activated carbon.

  5. Experimental Investigation of a Temperature-Controlled Car Seat Powered by an Exhaust Thermoelectric Generator

    Science.gov (United States)

    Du, H.; Wang, Y. P.; Yuan, X. H.; Deng, Y. D.; Su, C. Q.

    2016-03-01

    To improve the riding comfort and rational utilization of the electrical energy captured by an automotive thermoelectric generator (ATEG), a temperature-controlled car seat was constructed to adjust the temperature of the car seat surface. Powered by the ATEG and the battery, the seat-embedded air conditioner can improve the riding comfort using a thermoelectric device to adjust the surface temperature of the seat, with an air duct to regulate the cold side and hot side of the thermoelectric device. The performance of the thermoelectric cooler (TEC) and theoretical analysis on the optimum state of the TEC device are put forward. To verify the rationality of the air duct design and to ensure sufficient air supply, the velocity field of the air duct system was obtained by means of the finite element method. To validate the reliability of the numerical simulation, the air velocity around the thermoelectric device was measured by a wind speed transmitter. The performance of the temperature-controlled car seat has been validated and is in good agreement with bench tests and real vehicle tests.

  6. Experimental characterization of powered Fontan hemodynamics in an idealized total cavopulmonary connection model

    Science.gov (United States)

    Kerlo, Anna-Elodie M.; Delorme, Yann T.; Xu, Duo; Frankel, Steven H.; Giridharan, Guruprasad A.; Rodefeld, Mark D.; Chen, Jun

    2013-08-01

    A viscous impeller pump (VIP) based on the Von Karman viscous pump is specifically designed to provide cavopulmonary assist in a univentricular Fontan circulation. The technology will make it possible to biventricularize the univentricular Fontan circulation. Ideally, it will reduce the number of surgeries required for Fontan conversion from three to one early in life, while simultaneously improving physiological conditions. Later in life, it will provide a currently unavailable means of chronic support for adolescent and adult patients with failing Fontan circulations. Computational fluid dynamics simulations demonstrate that the VIP can satisfactorily augment cavopulmonary blood flow in an idealized total cavopulmonary connection (TCPC). When the VIP is deployed at the TCPC intersection as a static device, it stabilizes the four-way flow pattern and is not obstructive to the flow. Experimental studies are carried out to assess performance, hemodynamic characteristics, and flow structures of the VIP in an idealized TCPC model. Stereoscopic particle image velocimetry is applied using index-matched blood analog. Results show excellent performance of the VIP without cavitation and with reduction of the energy losses. The non-rotating VIP smoothes and accelerates flow, and decreases stresses and turbulence in the TCPC. The rotating VIP generates the desired low-pressure Fontan flow augmentation (0-10 mmHg) while maintaining acceptable stress thresholds.

  7. Hydrogen production by reforming of liquid hydrocarbons in a membrane reactor for portable power generation-Experimental studies

    Science.gov (United States)

    Damle, Ashok S.

    One of the most promising technologies for lightweight, compact, portable power generation is proton exchange membrane (PEM) fuel cells. PEM fuel cells, however, require a source of pure hydrogen. Steam reforming of hydrocarbons in an integrated membrane reactor has potential to provide pure hydrogen in a compact system. Continuous separation of product hydrogen from the reforming gas mixture is expected to increase the yield of hydrogen significantly as predicted by model simulations. In the laboratory-scale experimental studies reported here steam reforming of liquid hydrocarbon fuels, butane, methanol and Clearlite ® was conducted to produce pure hydrogen in a single step membrane reformer using commercially available Pd-Ag foil membranes and reforming/WGS catalysts. All of the experimental results demonstrated increase in hydrocarbon conversion due to hydrogen separation when compared with the hydrocarbon conversion without any hydrogen separation. Increase in hydrogen recovery was also shown to result in corresponding increase in hydrocarbon conversion in these studies demonstrating the basic concept. The experiments also provided insight into the effect of individual variables such as pressure, temperature, gas space velocity, and steam to carbon ratio. Steam reforming of butane was found to be limited by reaction kinetics for the experimental conditions used: catalysts used, average gas space velocity, and the reactor characteristics of surface area to volume ratio. Steam reforming of methanol in the presence of only WGS catalyst on the other hand indicated that the membrane reactor performance was limited by membrane permeation, especially at lower temperatures and lower feed pressures due to slower reconstitution of CO and H 2 into methane thus maintaining high hydrogen partial pressures in the reacting gas mixture. The limited amount of data collected with steam reforming of Clearlite ® indicated very good match between theoretical predictions and

  8. Enhanced resolution in Argon and Neon spectra using a Super-Resolution algorithm

    CERN Document Server

    Hoyos-Campo, L M; Capella, A

    2016-01-01

    This paper presents the principles and application of a super-resolution (SR) technique aimed to obtain high resolution spectra obtained from the optogalvanic effect in Neon and Argon discharges over the 413-423 nm wavelength range. By applying the super-resolution algorithm to the experimental data, a surprising 70-fold reduction of the linewidth is achieved allowing to resolve prior indistinguishable peaks. In addition to this, the limits on the applicability of this powerful mathematical technique, mainly the signal to noise ratio of the original spectra, as well as the potential applications of the SR algorithm in other spectroscopic applications are discussed upon.

  9. MaRaCluster: A Fragment Rarity Metric for Clustering Fragment Spectra in Shotgun Proteomics.

    Science.gov (United States)

    The, Matthew; Käll, Lukas

    2016-03-04

    Shotgun proteomics experiments generate large amounts of fragment spectra as primary data, normally with high redundancy between and within experiments. Here, we have devised a clustering technique to identify fragment spectra stemming from the same species of peptide. This is a powerful alternative method to traditional search engines for analyzing spectra, specifically useful for larger scale mass spectrometry studies. As an aid in this process, we propose a distance calculation relying on the rarity of experimental fragment peaks, following the intuition that peaks shared by only a few spectra offer more evidence than peaks shared by a large number of spectra. We used this distance calculation and a complete-linkage scheme to cluster data from a recent large-scale mass spectrometry-based study. The clusterings produced by our method have up to 40% more identified peptides for their consensus spectra compared to those produced by the previous state-of-the-art method. We see that our method would advance the construction of spectral libraries as well as serve as a tool for mining large sets of fragment spectra. The source code and Ubuntu binary packages are available at https://github.com/statisticalbiotechnology/maracluster (under an Apache 2.0 license).

  10. Experimental measurements concerning the stator insulation partial discharge level of a hydro-generator of high power

    Science.gov (United States)

    Haţiegan, C.; Răduca, E.; Popescu, C.; Hamat, C. O.; Băra, A.; Anghel, D.; Pîrşan, D. A.

    2018-01-01

    The paper presents a determining and evaluating method from an experimental point of view of the partial discharges level from the insulation of the stator of a synchronous hydro-generator of high power that appear at different temperatures. The temperature is measured directly on the coil with placed thermo-resistant elements between the superior and inferior bars. Also, the level of partial discharges with the coil age in a cold state, at the temperature level of the surrounding environment from within the stator, but also in a warm state at different temperatures, is measured. Through this method there is created the possibility of highlighting some eventual degradations of the coil insulation of a hydro-generator.

  11. Review of experimental research with models of two-circuit liquid-metal power installation for space application

    Science.gov (United States)

    Fedorovich, Evgeny D.; Kudriavtsev, Igor; Repnikova, Elena A.

    2002-01-01

    In this paper test apparatus with experimental loop, containing model of primary circuit (lithium, sodium) and secondary circuit (potassium and potassium vapor) of power system for space based on Rankine thermodynamic cycle is presented. The history and multi-years experience with these types of facilities are described for the whole system and its particular components (steam generators, vapor condensers, electromagnetic pumps, devices for potassium cleaning from impurities etc.), instrumentation and methods for measurement. Simulated nuclear heat sources in the form of a high-frequency electric heater and its operation characteristics are examined. Historical insights and lessons learned from work of several technological laboratories over a twenty year period give material and information for adequate evaluation of status in considered area. .

  12. The role of laser power and pullback velocity in the endovenous laser ablation efficacy: an experimental study.

    Science.gov (United States)

    Ignatieva, N Yu; Zakharkina, O L; Masayshvili, C V; Maximov, S V; Bagratashvili, V N; Lunin, V V

    2017-07-01

    Endovenous laser ablation is an effective and minimally invasive alternative to surgical removal of incompetent veins. However, many controversies concerning optimal laser parameters usage in this procedure still remain. The purpose of this experimental study was to assess the adequate parameters required for vein wall destruction and to evaluate the role of fiber pullback velocity on vessel wall degradation. Varicose vein segments were treated with 1470-nm diode laser 3 to 9.5 W in power. The fiber moved through the vein at a velocity of 0.7 or 1.5 mm/s; the applied linear endovenous energy density (LEED) was 40-95 J/cm. The temperature of the vein surface in the course of laser irradiation was controlled by IR thermography. The intact collagen in treated vein specimens was studied by differential scanning calorimetry. The increase in the surface temperature with applied energy was found to be about three times slower for the pullback velocity of 0.7 mm/s than that of 1.5 mm/s. The collagen in the tissue was totally denatured in the case of the surface temperature of about 91 °C. The critical values of LEED ensured complete degradation of vein wall were of 53 and 71.5 J/cm for velocities of 1.5 and 0.7 mm/s, respectively. Our experimental study supports the conception that it is laser power and pullback velocity rather than LEED value that determine the temperature as well the collagen framework degradation and therefore the thermal response of procedure.

  13. Photo-degradation of basic green 1 and basic red 46 dyes in their binary solution by La2O3-Al2O3nanocomposite using first-order derivative spectra and experimental design methodology.

    Science.gov (United States)

    Fahimirad, Bahareh; Asghari, Alireza; Rajabi, Maryam

    2017-05-15

    In this work, the lanthanum oxide-aluminum oxide (La2O3-Al2O3) nanocomposite is introduced as an efficient photocatalyst for the photo-degradation of the dyes basic green 1 (BG1) and basic red 46 (BR46) in their binary aqueous solution under the UV light irradiation. The properties of this catalyst are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. The first-order derivative spectra are used for the simultaneous analysis of the dyes in their binary solution. The screening investigations indicate that five parameters including the catalyst dosage, concentration of the dyes, irradiation time, and solution pH have significant effects on the photo-degradation of the dyes. The effects of these variables together with their interactions in the photo-degradation of the dyes are studied using the Box-Behnken design (BBD). Under the optimum experimental conditions, obtained via the desirability function, the photo-catalytic activities of La2O3-Al2O3 and pure Al2O3 are also investigated. The results obtained show an enhancement in the photo-catalytic activity when La2O3 nanoparticles are loaded on the surface of Al2O3 nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Photo-degradation of basic green 1 and basic red 46 dyes in their binary solution by La2O3-Al2O3nanocomposite using first-order derivative spectra and experimental design methodology

    Science.gov (United States)

    Fahimirad, Bahareh; Asghari, Alireza; Rajabi, Maryam

    2017-05-01

    In this work, the lanthanum oxide-aluminum oxide (La2O3-Al2O3) nanocomposite is introduced as an efficient photocatalyst for the photo-degradation of the dyes basic green 1 (BG1) and basic red 46 (BR46) in their binary aqueous solution under the UV light irradiation. The properties of this catalyst are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. The first-order derivative spectra are used for the simultaneous analysis of the dyes in their binary solution. The screening investigations indicate that five parameters including the catalyst dosage, concentration of the dyes, irradiation time, and solution pH have significant effects on the photo-degradation of the dyes. The effects of these variables together with their interactions in the photo-degradation of the dyes are studied using the Box-Behnken design (BBD). Under the optimum experimental conditions, obtained via the desirability function, the photo-catalytic activities of La2O3-Al2O3 and pure Al2O3 are also investigated. The results obtained show an enhancement in the photo-catalytic activity when La2O3 nanoparticles are loaded on the surface of Al2O3 nanoparticles. The La2O3-Al2O3nanocomposite was synthesized as new photo-catalyst for the degradation of binary dyes. The photo-catalytic effect on the binary dyes solution was followed by the first-order derivative spectrophotometric method. Simultaneous dyes photodegradation methodology was presented by using experimental design.

  15. Vibrational spectra (experimental and theoretical), molecular structure, natural bond orbital, HOMO-LUMO energy, Mulliken charge and thermodynamic analysis of N'-hydroxy-pyrimidine-2-carboximidamide by DFT approach.

    Science.gov (United States)

    Jasmine, N Jeeva; Muthiah, P Thomas; Arunagiri, C; Subashini, A

    2015-06-05

    The FT-IR, FT-Raman, (1)H, (13)C NMR and UV-Visible spectral measurements of N'-hydroxy-pyrimidine-2-carboximidamide (HPCI) and complete analysis of the observed spectra have been proposed. DFT calculation has been performed and the structural parameters of the compound was determined from the optimized geometry with 6-311+G(d,p) basis set and giving energies, harmonic vibrational frequencies and force constants. The results of the optimized molecular structure are presented and compared with the experimental. The geometric parameters, harmonic vibrational frequencies and chemical shifts were compared with the experimental data of the molecule. The title compound, C5H6N4O, is approximately planar, with an angle of 11.04 (15)°. The crystal structure is also stabilized by intermolecular N-H⋯O, N-H⋯N, O-H⋯N, C-H⋯O hydrogen bond and offset π-π stacking interactions. The influences of hydroxy and carboximidamide groups on the skeletal modes and proton chemical shifts have been investigated. Moreover, we have not only simulated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) but also determined the transition state and band gap. The kinetic, thermodynamic stability and chemical hardness of the molecule have been determined. Complete NBO analysis was also carried out to find out the intermolecular electronic interactions and their stabilization energy. The thermodynamic properties like entropies and their correlations with temperatures were also obtained from the harmonic frequencies of the optimized structure. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Experimental investigation of the liquid film for annular flow in a tube with various axial power distributions

    Energy Technology Data Exchange (ETDEWEB)

    Carl Adamsson; Henryk Anglart; Per Persson; Stellan Hedberg [Nuclear Reactor Technology Royal Institute of Technology, SE-100 44, Stockholm (Sweden)

    2005-07-01

    Full text of publication follows: The phenomenon of critical heat flux (CHF) is of great importance in various boiling system, since it defines an upper limit of the achievable heat transfer performance. In particular in BWR type nuclear reactors, CHF occurs through the process of dryout, i.e the disappearance of the liquid film from the heated surface. A mechanistic dryout model will have to be able to accurately predict the development of the liquid film, which will require accurate models for the deposition and entrainment rates of liquid droplets. Several researches have measured the film flow under various conditions by different methods. One of the most common is to suck the film of the wall through a porous wall section and performing a heat balance calculation. This method, which is also used in the experiments described here, has been used in round tubes as well as in annuli. In some experiments the film-flow was measured at several locations along the tube by simply varying the heated length; see Bennet (1966) and Moeck (1970). Other researches have used various axial and lateral (in annuli) power distributions; see Mannov (1973). Bennet (1966) used a moveable cold patch to investigate the influence of the axial power profile on the film thickness. What has not been done - to the authors' knowledge - is to measure the film at several axial locations for general non-uniform axial power distributions, similar to those found in nuclear reactors. Thus, this is the focus of the present experiment, where the influence of the axial power distribution on the axial distribution of the liquid film flow rate has been investigated. It is well known that the axial power profile has a significant influence on the dryout power and the dryout location. In the ongoing experimental program the dependence of the liquid film on the power profile is investigated. The results will be used to validate several correlations in common use for the prediction of deposition and

  17. Experimental study of the critical point region of aluminum under the action of the powerful nanosecond laser pulse

    Science.gov (United States)

    Cherepetskaya, E. B.; Karabutov, A. A.; Kaptilniy, A. G.; Ksenofontov, D. M.; Makarov, V. A.; Podymova, N. B.

    2015-12-01

    This paper is a report on the novel experimental method of the study of the thermodynamic parameters of thin aluminum films in the critical point region. The controlled supercritical state of aluminum is achieved for the first time as a result of the heating of these films by the absorption of the powerful nanosecond pulse of Q-switched Nd:YAG laser at the fundamental wavelength. The possibility is demonstrated to find simultaneously the temporal dependencies of the temperature, of the pressure and of the density of aluminum during the experiment with the thin aluminum films confined at both sides by the quartz glass substrates. These dependencies are obtained taking into account the nonlinear dependence on the incident laser intensity of the light reflection coefficient from the irradiated surface of aluminum. For the first time the thermodynamic cooling cycle of aluminum after its heating by the powerful nanosecond laser pulse is plotted in the space of variables’ temperature—pressure and temperature—density that get into the supercritical region.

  18. Experimental investigation and modelling of tritium washout by precipitation in the area of the nuclear power plant of Paks, Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Koello, Z., E-mail: kolloz42@gmail.co [Hertelendi Laboratory of Environmental Studies, Institute of Nuclear Research of the Hungarian Academy of Sciences, Bem ter 18/c, Debrecen 4026 (Hungary); Palcsu, L.; Major, Z.; Papp, L.; Molnar, M. [Hertelendi Laboratory of Environmental Studies, Institute of Nuclear Research of the Hungarian Academy of Sciences, Bem ter 18/c, Debrecen 4026 (Hungary); Ranga, T.; Dombovari, P.; Manga, L. [Department of Radiation Protection, Nuclear Power Plant of Paks, Paks (Hungary)

    2011-01-15

    Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate {sup 3}He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to estimate the distribution of tritium around the plant. The model gives slightly higher concentrations than those measured in the field, but in general the agreement is satisfactory. The modelled values demonstrate that the effect of the plant on rainwater tritium levels is negligible over a distance of some kilometres. - Research highlights: {yields}The rainwater around a nuclear power plant was collected with a special rainwater collector {yields}The rainwater after a rain event was analysed for tritium with LSC and with the helium ingrowth method. {yields}The trace of the tritium plume is clearly detectable in the rainwater. {yields}The agreement between a reversible washout model and experimental data is satisfactory. {yields}According to the model the tritium plume is hardly detectable over some kilometers from the plant

  19. Experimental investigation on the relationship between sluice caisson shape of tidal power plant and the water discharge capability

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dal Soo; Oh, Sang-Ho; Yi, Jin-Hak; Park, Woo-Sun [Coastal Engineering and Ocean Energy Research Department, Korea Ocean Research and Development Institute, Ansan 426-744 (Korea); Cho, Hyu-Sang; Kim, Duk-Gu; Ahn, Suk-Jin [Technology Research and Development Institute, Hyein E and C Co. Ltd., Seoul 157-861 (Korea); Eom, Hyun-Min [Global Environment System Research Laboratory, National Institute of Meteorological Research/KMA, Seoul 156-720 (Korea)

    2010-10-15

    The change of water discharge capability of the sluice caisson of tidal power plant according to the change of geometrical shape of the sluice caisson was investigated by performing laboratory experiments. The major design parameters that constitute general shape of the sluice caisson were deduced and a total of 32 different shapes of sluice caisson models were subjected to the hydraulic experiments. For every sluice caisson model, the water discharge capability was estimated with five different flow rates and three different water level conditions. The experiments were carried out in an open channel flume with a great care to measure flow rate and water level accurately, which are key physical quantities in estimating the water discharge capability of the sluice caisson models. By analyzing the experimental results, influence of the respective design parameters on the performance of the sluice caisson was examined and the general guidelines to enhance the water discharge capability were suggested. The discharge coefficient of the best sluice caisson model ranged from 2.3 to 3.1 depending on the experimental conditions, which is far higher than the values that were adopted in the past feasibility studies in Korea. (author)

  20. Spectra of stable sonoluminescence

    Science.gov (United States)

    Lewis, Stephen D.

    1992-12-01

    The continuous emission of picosecond pulses of light has been observed to originate from a bubble trapped at the pressure antinode of a resonant sound field in water and in water/glycerin mixtures. The spectra of this light in several solutions has been measured with a scanning monochrometer/photomultiplier detector system. The spectra are broadband and show strong emission in the UV region. A comparison of this measurement to two other independently produced spectra is made. The spectra are also modeled by a blackbody radiation distribution to determine an effective blackbody temperature and a size is deduced as if Sonoluminescence were characterized by blackbody radiation.

  1. General Notes on Processes and Their Spectra

    Directory of Open Access Journals (Sweden)

    Gustav Cepciansky

    2012-01-01

    Full Text Available The frequency spectrum performs one of the main characteristics of a process. The aim of the paper is to show the coherence between the process and its own spectrum and how the behaviour and properties of a process itself can be deduced from its spectrum. Processes are categorized and general principles of their spectra calculation and recognition are given. The main stress is put on power spectra of electric and optic signals, as they also perform a kind of processes. These spectra can be directly measured, observed and examined by means of spectral analyzers and they are very important characteristics which can not be omitted at transmission techniques in telecommunication technologies. Further, the paper also deals with non electric processes, mainly with processes and spectra at mass servicing and how these spectra can be utilised in praxis.

  2. Comprehensive thermal characterization using ruby R fluorescence lines of sapphire and GaNE{sub 2}-high Raman mode from Raman spectra in high-power flip-chip InGaN/GaN LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Cui, M; Zhou, T F; Wang, M R; Huang, J; Huang, H J; Zhang, J P; Xu, K; Yang, H, E-mail: kxu2006@sinano.ac.cn, E-mail: tfzhou2007@sinano.ac.cn [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123 (China)

    2011-09-07

    A comprehensive temperature characterization method based on the GaNE{sub 2}-high Raman mode and sapphire ruby R fluorescence lines from Raman spectra was developed to analyse the thermal distribution and heat transfer process of high-power flip-chip InGaN/GaN LEDs (FC LEDs). Our analysis demonstrated that in addition to the known problem that the edges of mesa were always the hottest point of FC LEDs, which was due to the current crowding effect, a noteworthy temperature difference was first observed between the sapphire substrate and n-GaN when the injection current was above 300 mA. A 'heat reservoir' was suggested to occur at the interface between the sapphire and n-GaN due to poor thermal conductivity of sapphire when a large amount of heat from the hottest spot cannot be effectively transferred to the Si mount via the active region under high injection currents.

  3. Resolution enhancement in second-derivative spectra.

    Science.gov (United States)

    Czarnecki, Mirosław A

    2015-01-01

    Derivative spectroscopy is a powerful tool for the resolution enhancement in infrared, near-infrared, Raman, ultraviolet-visible, nuclear magnetic resonance, electron paramagnetic resonance, and fluorescence spectroscopy. Despite its great significance in analytical chemistry, not all aspects of the applications of this method have been explored as yet. This is the first systematic study of the parameters that influence the resolution enhancement in the second derivative spectra. The derivative spectra were calculated with the Savitzky-Golay method with different window size (5, 15, 25) and polynomial order (2, 4). The results obtained in this work show that the resolution enhancement in the second derivative spectra strongly depends on the data spacing in the original spectra, window size, polynomial order, and peak profile. As shown, the resolution enhancement is related to variations in the width of the peaks upon the differentiation. The present study reveals that in order to maximize the separation of the peaks in the second derivative spectra, the original spectra should be recorded at high resolution and differentiated using a small window size and high polynomial order. However, working with the real spectra one has to compromise between the noise reduction and optimization of the resolution enhancement in the second derivative spectra.

  4. Statistical properties of Fermi GBM GRBs' spectra

    Science.gov (United States)

    Rácz, István I.; Balázs, Lajos G.; Horvath, Istvan; Tóth, L. Viktor; Bagoly, Zsolt

    2018-03-01

    Statistical studies of gamma-ray burst (GRB) spectra may result in important information on the physics of GRBs. The Fermi GBM catalogue contains GRB parameters (peak energy, spectral indices, and intensity) estimated fitting the gamma-ray spectral energy distribution of the total emission (fluence, flnc), and during the time of the peak flux (pflx). Using contingency tables, we studied the relationship of the models best-fitting pflx and flnc time intervals. Our analysis revealed an ordering of the spectra into a power law - Comptonized - smoothly broken power law - Band series. This result was further supported by a correspondence analysis of the pflx and flnc spectra categorical variables. We performed a linear discriminant analysis (LDA) to find a relationship between categorical (spectral) and model independent physical data. LDA resulted in highly significant physical differences among the spectral types, that is more pronounced in the case of the pflx spectra, than for the flnc spectra. We interpreted this difference as caused by the temporal variation of the spectrum during the outburst. This spectral variability is confirmed by the differences in the low-energy spectral index and peak energy, between the pflx and flnc spectra. We found that the synchrotron radiation is significant in GBM spectra. The mean low-energy spectral index is close to the canonical value of α = -2/3 during the peak flux. However, α is ˜ -0.9 for the spectra of the fluences. We interpret this difference as showing that the effect of cooling is important only for the fluence spectra.

  5. Nonlinear FMR spectra in yttrium iron garnet

    Directory of Open Access Journals (Sweden)

    Yu.M. Bunkov, P.M. Vetoshko, I.G. Motygullin, T.R. Safin, M.S. Tagirov, N.A. Tukmakova

    2015-12-01

    Full Text Available Results of demagnetizing effect studies in yttrium iron garnet Y3Fe5O12 thin films are reported. Experiments were performed on X-Band of electron paramagnetic resonance spectrometer at room temperature. The ferromagnetic resonance (FMR spectra were obtained for one-layer single crystal YIG films for different values of the applied microwave power. Nonlinear FMR spectra transformation by the microwave power increasing in various directions of magnetic field sweep was observed. It is explained by the influence of the demagnetization action of nonequilibrium magnons.

  6. Experimental assessment of blade tip immersion depth from free surface on average power and thrust coefficients of marine current turbine

    Science.gov (United States)

    Lust, Ethan; Flack, Karen; Luznik, Luksa

    2014-11-01

    Results from an experimental study on the effects of marine current turbine immersion depth from the free surface are presented. Measurements are performed with a 1/25 scale (diameter D = 0.8m) two bladed horizontal axis turbine towed in the large towing tank at the U.S. Naval Academy. Thrust and torque are measured using a dynamometer, mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using a shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Two optical wave height sensors are used to measure the free surface elevation. The turbine is towed at 1.68 m/s, resulting in a 70% chord based Rec = 4 × 105. An Acoustic Doppler Velocimeter (ADV) is installed one turbine diameter upstream of the turbine rotation plane to characterize the inflow turbulence. Measurements are obtained at four relative blade tip immersion depths of z/D = 0.5, 0.4, 0.3, and 0.2 at a TSR value of 7 to identify the depth where free surface effects impact overall turbine performance. The overall average power and thrust coefficient are presented and compared to previously conducted baseline tests. The influence of wake expansion blockage on the turbine performance due to presence of the free surface at these immersion depths will also be discussed.

  7. An experimental setup for the simultaneous measurement of thermoelectric power of two samples from 77 K to 500 K

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, T. S.; Bala, M.; Asokan, K. [Materials Science Division, IUAC, New Delhi 110067 (India)

    2014-08-01

    We report on an experimental setup for the simultaneous measurement of the thermoelectric power (TEP) of two samples in the temperature range from 77 K to 500 K using optimum electronic instruments. The setup consists of two rectangular copper bars in a bridge arrangement for sample mounting, two surface mount (SM) chip resistors for creating alternate temperature gradient, and a type E thermocouple in differential geometry for gradient temperature (ΔT) measurement across the samples. In addition, a diode arrangement has been made for the alternate heating of SM resistors using only one DC current source. The measurement accuracy of ΔT increases with the differential thermocouple arrangement. For the calibration of the setup, measurements of TEP on a high purity (99.99%) platinum wire and type K thermocouple wires Chromel and Alumel have been performed from 77 K to 500 K with respect to copper lead wires. Additionally, this setup can be utilized to calibrate an unknown sample against a sample of known absolute TEP.

  8. Experimental investigations of an AC pulse heating method for vehicular high power lithium-ion batteries at subzero temperatures

    Science.gov (United States)

    Zhu, Jiangong; Sun, Zechang; Wei, Xuezhe; Dai, Haifeng; Gu, Weijun

    2017-11-01

    Effect of the AC (alternating current) pulse heating method on battery SoH (state of health) for large laminated power lithium-ion batteries at low temperature is investigated experimentally. Firstly, excitation current frequencies, amplitudes, and voltage limitations on cell temperature evolution are studied. High current amplitudes facilitate the heat accumulation and temperature rise. Low frequency region serves as a good innovation to heat the battery because of the large impedance. Wide voltage limitations also enjoy better temperature evolution owing to the less current modulation, but the temperature difference originated from various voltage limitations attenuates due to the decrement of impedance resulting from the temperature rise. Experiments with the thermocouple-embedded cell manifest good temperature homogeneity between the battery surface and interior during the AC heating process. Secondly, the cell capacity, Direct Current resistance and Electrochemical Impedance Spectroscopy are all calibrated to assess the battery SoH after the hundreds of AC pulse heating cycles. Also, all cells are disassembled to investigate the battery internal morphology with the employment of Scanning Electron Microscope and Energy-Dispersive x-ray Spectroscopy techniques. The results indicate that the AC heating method does not aggravate the cell degradation even in the low frequency range (0.5 Hz) under the normal voltage protection limitation.

  9. Experimental studies and economic considerations on a living space heated through passive solar gain and through electric power

    Directory of Open Access Journals (Sweden)

    Luminosu Iona

    2003-01-01

    Full Text Available The Trombe wall, of an area AT = 8.8 m, built on the southern facade of a room, heats the accommodation during the transition months, complementary to electric power. The statistical processing of the experimental data led to a global quantitative image of the wall’s behavior during the average day of the months March, April, September, and October 1999. The inner climate parameters are: tint = = 21 °C, trad = 17.9 °C, troom= 19.5 °C, j= 35-70%, E Î80 + 120 lx. The thermal comfort factor is B = -0.325. These values insure a room’s comfort close to the optimal one prescribed by the hygienists. The heliothermal conversion’s efficiency is hT = 10.4%. The proportion of heat supplied by the wall in the entire energy required by the room is hheat = 45.8%. The wall’s specific cost is Pu = 24.9 € /m. The write-off period of the initial investment is n = 53 years. The development of passive solar architecture in the Euro-region Danube-Cris-Mures-Tisa which includes the town of Timisoara (45° north, 22° east, was proven feasible by the experiments from both the energy and the economical point of view.

  10. Experimental verification of stopping-power prediction from single- and dual-energy computed tomography in biological tissues

    Science.gov (United States)

    Möhler, Christian; Russ, Tom; Wohlfahrt, Patrick; Elter, Alina; Runz, Armin; Richter, Christian; Greilich, Steffen

    2018-01-01

    An experimental setup for consecutive measurement of ion and x-ray absorption in tissue or other materials is introduced. With this setup using a 3D-printed sample container, the reference stopping-power ratio (SPR) of materials can be measured with an uncertainty of below 0.1%. A total of 65 porcine and bovine tissue samples were prepared for measurement, comprising five samples each of 13 tissue types representing about 80% of the total body mass (three different muscle and fatty tissues, liver, kidney, brain, heart, blood, lung and bone). Using a standard stoichiometric calibration for single-energy CT (SECT) as well as a state-of-the-art dual-energy CT (DECT) approach, SPR was predicted for all tissues and then compared to the measured reference. With the SECT approach, the SPRs of all tissues were predicted with a mean error of (‑0.84  ±  0.12)% and a mean absolute error of (1.27  ±  0.12)%. In contrast, the DECT-based SPR predictions were overall consistent with the measured reference with a mean error of (‑0.02  ±  0.15)% and a mean absolute error of (0.10  ±  0.15)%. Thus, in this study, the potential of DECT to decrease range uncertainty could be confirmed in biological tissue.

  11. Atomic physics modeling of transmission spectra of Sc-doped aerogel foams to support OMEGA experiments

    Energy Technology Data Exchange (ETDEWEB)

    Johns, H. M., E-mail: hjohns@lanl.gov; Lanier, N. E.; Kline, J. L.; Fontes, C. J.; Perry, T. S.; Fryer, C. L.; Sherrill, M. E. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544 (United States); Brown, C. R. D.; Morton, J. W. [AWE Aldermaston, Berkshire, Reading RG7 4PR (United Kingdom); Hager, J. D. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544 (United States); Lockheed-Martin, 497 Electronics Parkway, Syracuse, New York 13221 (United States)

    2016-11-15

    We present synthetic transmission spectra generated with PrismSPECT utilizing both the ATBASE model and the Los Alamos opacity library (OPLIB) to evaluate whether an alternative choice in atomic data will impact modeling of experimental data from radiation transport experiments using Sc-doped aerogel foams (ScSi{sub 6}O{sub 12} at 75 mg/cm{sup 3} density). We have determined that in the 50-200 eV T{sub e} range there is a significant difference in the 1s-3p spectra, especially below 100 eV, and for T{sub e} = 200 eV above 5000 eV in photon energy. Examining synthetic spectra generated using OPLIB with 300 resolving power reveals spectral sensitivity to T{sub e} changes of ∼3 eV.

  12. SAWYER ASTEROID SPECTRA

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains 94 optical asteroid spectra obtained by Scott Sawyer as part of his Ph.D. dissertation at the University of Texas at Austin. Observational...

  13. Experimental study on an S-band near-field microwave magnetron power transmission system on hundred-watt level

    Science.gov (United States)

    Zhang, Biao; Jiang, Wan; Yang, Yang; Yu, Chengyang; Huang, Kama; Liu, Changjun

    2015-11-01

    A multi-magnetron microwave source, a metamaterial transmitting antenna, and a large power rectenna array are presented to build a near-field 2.45 GHz microwave power transmission system. The square 1 m2 rectenna array consists of sixteen rectennas with 2048 Schottky diodes for large power microwave rectifying. It receives microwave power and converts them into DC power. The design, structure, and measured performance of a unit rectenna as well as the entail rectenna array are presented in detail. The multi-magnetron microwave power source switches between half and full output power levels, i.e. the half-wave and full-wave modes. The transmission antenna is formed by a double-layer metallic hole array, which is applied to combine the output power of each magnetron. The rectenna array DC output power reaches 67.3 W on a 1.2 Ω DC load at a distance of 5.5 m from the transmission antenna. DC output power is affected by the distance, DC load, and the mode of microwave power source. It shows that conventional low power Schottky diodes can be applied to a microwave power transmission system with simple magnetrons to realise large power microwave rectifying.

  14. Information manual for the experimentation of the deployment of optical fibers on public power distribution networks; Notice d'information pour l'experimentation du deploiement de fibres optiques sur les reseaux publics d'electricite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    During the French inter-ministry committee for the national development (CIADT) of July 9, 2001, the government decided to launch a feasibility study about the deployment of telecommunication optical fibers over the whole territory using the electricity transportation grid. The aim is to give access to high-speed Internet to everyone and at a reasonable cost. This manual summarizes the technical, legal and economical results of the study carried out by the working group: 1 - the actors in concern (managers of power transportation and distribution networks, country authorities, managers and users of telecommunication infrastructures, regulatory agencies, financial organizations); 2 - the telecommunication networks on power lines; 3 - the feasibility of the experimentation (relations between the different partners, conditions); 4 - the implementation of the experimentation (useful contacts, contracts); 5 - the experimentation areas. Appendixes. (J.S.)

  15. Pascal's triangle and the simulation of backscattering spectra

    Science.gov (United States)

    Bozoian, Michael

    1994-04-01

    Applying a well-known yield equation to a stack of very thin sublayers allows accurate simulations of homogeneous, thick-target, backscattering spectra. Explicit expressions, accurate to at least third degree in the areal density for the ion energy immediately before scattering and for the detected ion energy, are found. These expressions are in terms of binomial expansions of a quantity equaling the product of the areal density multiplied by a function of stopping cross section derivatives and areal density. One iterative parameter, taken as the near-surface yield, is required to properly normalize the simulation with respect to the experimental spectrum. Several thick target spectra, produced by bombarding helium ions with energies ranging over several MeV, are simulated using both Ziegler's 1977 [J.F. Ziegler, Helium Stopping Powers and Ranges in All Elements (Pergamon, New York, 1977)] and 1985 [J.F. Ziegler, J.P. Biersack and U. Littmark, The Stopping and Range of Ions in Solids (Pergamon, New York, 1985)] stopping compilations to ascertain the impact of these differing stopping cross sections on predictions of backscattering spectra.

  16. Experimental analysis of neutron and background gamma-ray energy spectra of 80-400 MeV 7Li(p,n reactions under the quasi-monoenergetic neutron field at RCNP, Osaka University

    Directory of Open Access Journals (Sweden)

    Iwamoto Yosuke

    2017-01-01

    Full Text Available To develop the 100-400 MeV quasi-monoenergetic neutron field, we measured neutron and unexpected gamma-ray energy spectra of the 7Li(p,n reaction with 80-389 MeV protons in the 100-m time-of-flight (TOF tunnel at the Research Center for Nuclear Physics (RCNP cyclotron facility. Neutron energy spectra with energies above 3 MeV were measured by the TOF method, which had been reported in our previous papers, and photon energy spectra with energies above 0.1 MeV were measured by the automatic unfolding function of the radiation dose monitor DARWIN. For neutron spectra, the contribution of peak intensity to the total intensity integrated with energies above 3 MeV varied between 0.38 and 0.48 in the proton energy range of 80–389 MeV. For gamma-ray spectra, highenergetic gamma-rays at around 70 MeV originated from the decay of π0 were observed with proton energies higher than 200 MeV. For the 246-MeV proton incident reaction, the contribution of gamma-ray dose to neutron dose is negligible because the ratio of gamma-ray dose to neutron dose is 0.014.

  17. RAMAN-SPECTRA OF HUMAN DENTAL CALCULUS

    NARCIS (Netherlands)

    TSUDA, H; ARENDS, J

    1993-01-01

    Raman spectra of human dental calculus have been observed for the first time by use of micro-Raman spectroscopy. The spectral features of calculus were influenced easily by heating caused by laser irradiation. Therefore, the measurements were carried out at relatively low power (5 mW, 1-mu m spot

  18. "PowerUp"!: A Tool for Calculating Minimum Detectable Effect Sizes and Minimum Required Sample Sizes for Experimental and Quasi-Experimental Design Studies

    Science.gov (United States)

    Dong, Nianbo; Maynard, Rebecca

    2013-01-01

    This paper and the accompanying tool are intended to complement existing supports for conducting power analysis tools by offering a tool based on the framework of Minimum Detectable Effect Sizes (MDES) formulae that can be used in determining sample size requirements and in estimating minimum detectable effect sizes for a range of individual- and…

  19. Experimental Investigation from the Operation of a 2 kW Brayton Power Conversion Unit and a Xenon Ion Thruster

    Science.gov (United States)

    Hervol, David; Mason, Lee; Birchenough, Art; Pinero, Luis

    2004-01-01

    A 2kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton Converters and ion thrusters are potential candidates for use on future high power NEP mission such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of a existing lower power test hardware provided a cost effective means to investigate the critical electrical interface between the power conversion system and the propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

  20. Experimental Investigations from the Operation of a 2 Kw Brayton Power Conversion Unit and a Xenon Ion Thruster

    Science.gov (United States)

    Mason, Lee; Birchenough, Arthur; Pinero, Luis

    2004-01-01

    A 2 kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton converters and ion thrusters are potential candidates for use on future high power NEP missions such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of existing lower power test hardware provided a cost-effective means to investigate the critical electrical interface between the power conversion system and ion propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

  1. Hiding the tobacco power wall reduces cigarette smoking risk in adolescents: using an experimental convenience store to assess tobacco regulatory options at retail point-of-sale.

    Science.gov (United States)

    Shadel, William G; Martino, Steven C; Setodji, Claude M; Scharf, Deborah M; Kusuke, Daniela; Sicker, Angela; Gong, Min

    2015-11-23

    This experiment tested whether changing the location or visibility of the tobacco power wall in a life sized replica of a convenience store had any effect on adolescents' susceptibility to future cigarette smoking. The study was conducted in the RAND StoreLab (RSL), a life sized replica of a convenience store that was developed to experimentally evaluate how changing aspects of tobacco advertising displays in retail point-of-sale environments influences tobacco use risk and behaviour. A randomised, between-subjects experimental design with three conditions that varied the location or visibility of the tobacco power wall within the RSL was used. The conditions were: cashier (the tobacco power wall was located in its typical position behind the cash register counter); sidewall (the tobacco power wall was located on a sidewall away from the cash register); or hidden (the tobacco power wall was located behind the cashier but was hidden behind an opaque wall). The sample included 241 adolescents. Hiding the tobacco power wall significantly reduced adolescents' susceptibility to future cigarette smoking compared to leaving it exposed (ie, the cashier condition; p=0.02). Locating the tobacco power wall on a sidewall away from the cashier had no effect on future cigarette smoking susceptibility compared to the cashier condition (p=0.80). Hiding the tobacco power wall at retail point-of-sale locations is a strong regulatory option for reducing the impact of the retail environment on cigarette smoking risk in adolescents. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. THE DETERMINATION OF THE BALLAST RESISTANCE USED FOR THE CONECTION TO AN EXPERIMENTAL STAND FOR THE STUDY OF THE HYDRO – WIND HYBRIYD POWER (CHHE

    Directory of Open Access Journals (Sweden)

    JOIAN R.

    2015-09-01

    Full Text Available This paper point out some of the experimental determinations that must be made in the achieving of a hidro - wind hybrid system. It highlights the design and implementation of a1 kW ballast resistor and 48 V nickel-chromium wire, with the diameter of 60 three millimeters and connecting cable at the wind turbine by electric panel. Thus, this experimental stand CHHE includes a wind turbine 1 kW, placed on the roof of the Technical University of Cluj Napoca (this place is favorable because the wind has high speeds at great height and hydro turbine type Pelton 1 kW power. The experimental stand for the study of CHHE hybrid energy system will allow the determination of more experimental conclusive on the impact of the achievement of an energy balance of the physical model.

  3. N uSTAR Hard X-Ray Data and Gemini 3D Spectra Reveal Powerful AGN and Outflow Histories in Two Low-redshift Lyα Blobs

    Science.gov (United States)

    Kawamuro, Taiki; Schirmer, Mischa; Turner, James E. H.; Davies, Rebecca L.; Ichikawa, Kohei

    2017-10-01

    We have shown that Lyα blobs (LABs) may still exist even at z˜ 0.3, about seven billion years later than most other LABs known (Shirmer et al.). Their luminous Lyα and [O iii] emitters at z˜ 0.3 offer new insights into the ionization mechanism. This paper focuses on the two X-ray brightest LABs at z˜ 0.3, SDSS J0113+0106 (J0113) and SDSS J1155-0147 (J1155), comparable in size and luminosity to “B1,” one of the best-studied LABs at z≳ 2. Our NuSTAR hard X-ray (3-30 keV) observations reveal powerful active galactic nuclei (AGN) with {L}2{--10{keV}}=(0.5{--}3)× {10}44 erg s-1. J0113 also faded by a factor of ˜5 between 2014 and 2016, emphasizing that variable AGN may cause apparent ionization deficits in LABs. Joint spectral analyses including Chandra data constrain column densities of {N}{{H}}={5.1}-3.3+3.1× {10}23 cm-2 (J0113) and {N}{{H}}={6.0}-1.1+1.4× {10}22 cm-2 (J1155). J0113 is likely buried in a torus with a narrow ionization cone, but ionizing radiation is also leaking in other directions, as revealed by our Gemini/GMOS 3D spectroscopy. The latter shows a bipolar outflow over 10 kpc, with a peculiar velocity profile that is best explained by AGN flickering. X-ray analysis of J1155 reveals a weakly absorbed AGN that may ionize over a wide solid angle, consistent with our 3D spectra. Extinction-corrected [O iii] log-luminosities are high, ˜43.6. The velocity dispersions are low, ˜100-150 km s-1, even at the AGN positions. We argue that this is a combination of high extinction hiding the turbulent gas and previous outflows that have cleared the escape paths for their successors.

  4. Atomic Spectra Database (ASD)

    Science.gov (United States)

    SRD 78 NIST Atomic Spectra Database (ASD) (Web, free access)   This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The NIST Atomic Spectroscopy Data Center has carried out these critical compilations.

  5. Simulation of the PEM fuel cell hybrid power train of an automated guided vehicle and comparison with experimental results

    NARCIS (Netherlands)

    Bram Veenhuizen; J.C.N. Bosma

    2009-01-01

    At HAN University research has been started into the development of a PEM fuel cell hybrid power train to be used in an automated guided vehicle. For this purpose a test facility is used with the possibility to test all important functional aspects of a PEM fuel cell hybrid power train. In this

  6. Experimental Research and Control Strategy of Pumped Storage Units Dispatching in the Taiwan Power System Considering Transmission Line Limits

    Directory of Open Access Journals (Sweden)

    Ming-Tse Kuo

    2013-07-01

    Full Text Available Taiwan’s power system is isolated and not supported by other interconnected systems. Consequently, the system frequency immediately reflects changes in the system loads. Pumped storage units are crucial for controlling power frequency. These units provide main or auxiliary capacities, reducing the allocation of frequency-regulating reserve (FRR and further reducing generation costs in system operations. Taiwan’s Longmen Nuclear Power Plant is set to be converted for commercial operations, which will significantly alter the spinning reserves in the power system. Thus, this study proposes a safe and economic pumped storage unit dispatch strategy. This strategy is used to determine the optimal FRR capacity and 1-min recovery frequency in a generator failure occurrence at the Longmen Power Plant. In addition, this study considered transmission capacity constraints and conducted power flow analysis of the power systems in Northern, Central, and Southern Taiwan. The results indicated that, in the event of a failure at Longmen Power Plant, the proposed strategy can not only recover the system frequency to an acceptable range to prevent underfrequency load-shedding, but can also mitigate transmission line overloading.

  7. Analysis and Experimental Verification of New Power Flow Control for Grid-Connected Inverter with LCL Filter in Microgrid

    Directory of Open Access Journals (Sweden)

    Herong Gu

    2014-01-01

    Full Text Available Microgrid is an effective way to integrate the distributed energy resources into the utility networks. One of the most important issues is the power flow control of grid-connected voltage-source inverter in microgrid. In this paper, the small-signal model of the power flow control for the grid-connected inverter is established, from which it can be observed that the conventional power flow control may suffer from the poor damping and slow transient response. While the new power flow control can mitigate these problems without affecting the steady-state power flow regulation. Results of continuous-domain simulations in MATLAB and digital control experiments based on a 32-bit fixed-point TMS320F2812 DSP are in good agreement, which verify the small signal model analysis and effectiveness of the proposed method.

  8. Analysis and experimental verification of new power flow control for grid-connected inverter with LCL filter in microgrid.

    Science.gov (United States)

    Gu, Herong; Guan, Yajuan; Wang, Huaibao; Wei, Baoze; Guo, Xiaoqiang

    2014-01-01

    Microgrid is an effective way to integrate the distributed energy resources into the utility networks. One of the most important issues is the power flow control of grid-connected voltage-source inverter in microgrid. In this paper, the small-signal model of the power flow control for the grid-connected inverter is established, from which it can be observed that the conventional power flow control may suffer from the poor damping and slow transient response. While the new power flow control can mitigate these problems without affecting the steady-state power flow regulation. Results of continuous-domain simulations in MATLAB and digital control experiments based on a 32-bit fixed-point TMS320F2812 DSP are in good agreement, which verify the small signal model analysis and effectiveness of the proposed method.

  9. Prediction of peptide fragment ion mass spectra by data mining techniques.

    Science.gov (United States)

    Dong, Nai-ping; Liang, Yi-Zeng; Xu, Qing-song; Mok, Daniel K W; Yi, Lun-zhao; Lu, Hong-mei; He, Min; Fan, Wei

    2014-08-05

    Accurate prediction of peptide fragment ion mass spectra is one of the critical factors to guarantee confident peptide identification by protein sequence database search in bottom-up proteomics. In an attempt to accurately and comprehensively predict this type of mass spectra, a framework named MS(2)PBPI is proposed. MS(2)PBPI first extracts fragment ions from large-scale MS/MS spectra data sets according to the peptide fragmentation pathways and uses binary trees to divide the obtained bulky data into tens to more than 1000 regions. For each adequate region, stochastic gradient boosting tree regression model is constructed. By constructing hundreds of these models, MS(2)PBPI is able to predict MS/MS spectra for unmodified and modified peptides with reasonable accuracy. Moreover, high consistency between predicted and experimental MS/MS spectra derived from different ion trap instruments with low and high resolving power is achieved. MS(2)PBPI outperforms existing algorithms MassAnalyzer and PeptideART.

  10. Algorithms for classification of astronomical object spectra

    Science.gov (United States)

    Wasiewicz, P.; Szuppe, J.; Hryniewicz, K.

    2015-09-01

    Obtaining interesting celestial objects from tens of thousands or even millions of recorded optical-ultraviolet spectra depends not only on the data quality but also on the accuracy of spectra decomposition. Additionally rapidly growing data volumes demands higher computing power and/or more efficient algorithms implementations. In this paper we speed up the process of substracting iron transitions and fitting Gaussian functions to emission peaks utilising C++ and OpenCL methods together with the NOSQL database. In this paper we implemented typical astronomical methods of detecting peaks in comparison to our previous hybrid methods implemented with CUDA.

  11. Experimental and numerical investigation on cladding of corrosion-erosion resistant materials by a high power direct diode laser

    Science.gov (United States)

    Farahmand, Parisa

    advantages due to creating coating layers with superior properties in terms of purity, homogeneity, low dilution, hardness, bonding, and microstructure. In the development of modern materials for hardfacing applications, the functionality is often improved by combining materials with different properties into composites. Metal Matrix Composite (MMC) coating is a composite material with two constituent parts, i.e., matrix and the reinforcement. This class of composites are addressing improved mechanical properties such as stiffness, strength, toughness, and tribological and chemical resistance. Fabrication of MMCs is to achieve a combination of properties not achievable by any of the materials acting alone. MMCs have attracted significant attention for decades due to their combination of wear-resistivity, corrosion-resistivity, thermal, electrical and magnetic properties. Presently, there is a strong emphasis on the development of advanced functional coatings for corrosion, erosion, and wear protection for different industrial applications. In this research, a laser cladding system equipped with a high power direct diode laser associated with gas driven metal powder delivery system was used to develop advanced MMC coatings. The high power direct diode laser used in this study offers wider beam spot, shorter wavelength and uniform power distribution. These properties make the cladding set-up ideal for coating due to fewer cladding tracks, lower operation cost, higher laser absorption, and improved coating qualities. In order to prevent crack propagation, porosity, and uniform dispersion of carbides in MMC coating, cladding procedure was assisted by an induction heater as a second heat source. The developed defect free MMC coatings were combined with nano-size particles of WC, rare earth (RE) element (La2O3), and Mo as a refractory metal to enhance mechanical properties, chemical composition, and subsequently improve the tribological performance of the coatings. The resistance

  12. Experimental Study on Active Cooling Systems Used for Thermal Management of High-Power Multichip Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Mehmet Kaya

    2014-01-01

    Full Text Available The objective of this study was to develop suitable cooling systems for high-power multichip LEDs. To this end, three different active cooling systems were investigated to control the heat generated by the powering of high-power multichip LEDs in two different configurations (30 and 2 × 15 W. The following cooling systems were used in the study: an integrated multi-fin heat sink design with a fan, a cooling system with a thermoelectric cooler (TEC, and a heat pipe cooling device. According to the results, all three systems were observed to be sufficient for cooling high-power LEDs. Furthermore, it was observed that the integrated multifin heat sink design with a fan was the most efficient cooling system for a 30 W high-power multichip LED. The cooling system with a TEC and 46 W input power was the most efficient cooling system for 2 × 15 W high-power multichip LEDs.

  13. Three phase active power filter with selective harmonics elimination

    Directory of Open Access Journals (Sweden)

    Sozański Krzysztof

    2016-03-01

    Full Text Available This paper describes a three phase shunt active power filter with selective harmonics elimination. The control algorithm is based on a digital filter bank. The moving Discrete Fourier Transformation is used as an analysis filter bank. The correctness of the algorithm has been verified by simulation and experimental research. The paper includes exemplary results of current waveforms and their spectra from a three phase active power filter.

  14. Noise spectra in balanced optical detectors based on transimpedance amplifiers

    Science.gov (United States)

    Masalov, A. V.; Kuzhamuratov, A.; Lvovsky, A. I.

    2017-11-01

    We present a thorough theoretical analysis and experimental study of the shot and electronic noise spectra of a balanced optical detector based on an operational amplifier connected in a transimpedance scheme. We identify and quantify the primary parameters responsible for the limitations of the circuit, in particular, the bandwidth and shot-to-electronic noise clearance. We find that the shot noise spectrum can be made consistent with the second-order Butterworth filter, while the electronic noise grows linearly with the second power of the frequency. Good agreement between the theory and experiment is observed; however, the capacitances of the operational amplifier input and the photodiodes appear significantly higher than those specified in manufacturers' datasheets. This observation is confirmed by independent tests.

  15. An experimental study of magnetic-field and temperature dependence on magnetic fluid’s heating power

    Energy Technology Data Exchange (ETDEWEB)

    Beković, Miloš, E-mail: milos.bekovic@uni-mb.si [University of Maribor, Faculty of Electrical Engineering and Computer Science (Slovenia); Trlep, Mladen; Jesenik, Marko; Goričan, Viktor [University of Maribor, Faculty of Electrical Engineering and Computer Science (Slovenia); Hamler, Anton, E-mail: anton.hamler@uni-mb.si [University of Maribor, Faculty of Electrical Engineering and Computer Science (Slovenia)

    2013-04-15

    This paper firstly presents a measurement system for determining the magnetic properties of magnetic fluids, based on three pickup coils. The accuracy of the system was tested on known samples and then used for the characterization of magnetic losses (heating power P) on the magnetic fluid sample using two different methods. The first method is based on determining the hysteresis loop area and the second on determining the complex susceptibility; and showed that both methods are equivalent. The aim of this paper was to identify the heating power of the liquid at a known value for the magnetic field, and the arbitrary temperature. Thus, we explored the actual reduction in the heating power due to the heating of the sample, which cannot be achieved without the temperature regulated heat bath using established calorimetric methods. -- Highlights: ► A new measurement system was tested with numerous samples, and results were promising. ► Magnetic fluid heating power was determined using a system of J-compensated coil. ► Complex susceptibility method results equal losses as hysteresis loops approach. ► Temperature dependent heating power was explored without the heath-bath . ► For larger magnetic fields a linear H dependence of heating power is revealed.

  16. Experimental investigation of high power pulsed 2.8 μm Er3+-doped ZBLAN fiber lasers

    Science.gov (United States)

    Shen, Yanlong; Wang, Yishan; Huang, Ke; Luan, Kunpeng; Chen, Hongwei; Tao, Mengmeng; Yu, Li; Yi, Aiping; Si, Jinhai

    2017-05-01

    We report on the recent progress on high power pulsed 2.8 μm Er3+-doped ZBLAN fiber laser through techniques of passively and actively Q-switching in our research group. In passively Q-switched operation, a diode-cladding-pumped mid-infrared passively Q-switched Er3+-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) was demonstrated. Stable pulse train was produced at a slope efficient of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ. The maximum peak power was calculated to be 21.9 W. In actively Q-switched operation, a diode-pumped actively Q-switched Er3+-doped ZBLAN fiber laser at 2.8 μm with an optical chopper was reported. The maximum laser pulse energy of up to 130 μJ and a pulse width of 127.3 ns at a repetition rate of 10 kHz with an operating wavelength of 2.78 μm was obtained, yielding the maximum peak power of exceeding 1.1 kW.

  17. Experimental energetic analysis of gas natural-powered fuel cell cogeneration plant; Analise energetica experimental de uma planta de co-geracao com celulas a combustivel e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose G.M.; Lopes, Francisco C.; Silva Junior, Fernando R.; Soares, Guilherme F.W.; Serra, Eduardo T. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economy of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  18. Spectra, Winter 2014

    Science.gov (United States)

    2014-01-01

    additional copies or more information, please email spectra@nrl.navy.mil. LEADINGEDGE 1 Contents 30 Navy Launches UAV from Submerged Submarine 31...the splash, Test Sub submerged and started moving underwater. Flying WANDA With the success of Test Sub, the Flimmer team applied the lessons to...coated for corrosion- proofing against the acidic environ- ment in the fuel cell and then welded together. Looking at the complexity of developing

  19. Experimental investigation into the fault response of superconducting hybrid electric propulsion electrical power system to a DC rail to rail fault

    Science.gov (United States)

    Nolan, S.; Jones, C. E.; Munro, R.; Norman, P.; Galloway, S.; Venturumilli, S.; Sheng, J.; Yuan, W.

    2017-12-01

    Hybrid electric propulsion aircraft are proposed to improve overall aircraft efficiency, enabling future rising demands for air travel to be met. The development of appropriate electrical power systems to provide thrust for the aircraft is a significant challenge due to the much higher required power generation capacity levels and complexity of the aero-electrical power systems (AEPS). The efficiency and weight of the AEPS is critical to ensure that the benefits of hybrid propulsion are not mitigated by the electrical power train. Hence it is proposed that for larger aircraft (~200 passengers) superconducting power systems are used to meet target power densities. Central to the design of the hybrid propulsion AEPS is a robust and reliable electrical protection and fault management system. It is known from previous studies that the choice of protection system may have a significant impact on the overall efficiency of the AEPS. Hence an informed design process which considers the key trades between choice of cable and protection requirements is needed. To date the fault response of a voltage source converter interfaced DC link rail to rail fault in a superconducting power system has only been investigated using simulation models validated by theoretical values from the literature. This paper will present the experimentally obtained fault response for a variety of different types of superconducting tape for a rail to rail DC fault. The paper will then use these as a platform to identify key trades between protection requirements and cable design, providing guidelines to enable future informed decisions to optimise hybrid propulsion electrical power system and protection design.

  20. Pattern recognition in spectra

    Science.gov (United States)

    Gebran, M.; Paletou, F.

    2017-06-01

    We present a new automated procedure that simultaneously derives the effective temperature Teff, surface gravity log g, metallicity [Fe/H], and equatorial projected rotational velocity ve sin i for stars. The procedure is inspired by the well-known PCA-based inversion of spectropolarimetric full-Stokes solar data, which was used both for Zeeman and Hanle effects. The efficiency and accuracy of this procedure have been proven for FGK, A, and late type dwarf stars of K and M spectral types. Learning databases are generated from the Elodie stellar spectra library using observed spectra for which fundamental parameters were already evaluated or with synthetic data. The synthetic spectra are calculated using ATLAS9 model atmospheres. This technique helped us to detect many peculiar stars such as Am, Ap, HgMn, SiEuCr and binaries. This fast and efficient technique could be used every time a pattern recognition is needed. One important application is the understanding of the physical properties of planetary surfaces by comparing aboard instrument data to synthetic ones.

  1. Estimating Spectra from Photometry

    Science.gov (United States)

    Bryce Kalmbach, J.; Connolly, Andrew J.

    2017-12-01

    Measuring the physical properties of galaxies such as redshift frequently requires the use of spectral energy distributions (SEDs). SED template sets are, however, often small in number and cover limited portions of photometric color space. Here we present a new method to estimate SEDs as a function of color from a small training set of template SEDs. We first cover the mathematical background behind the technique before demonstrating our ability to reconstruct spectra based upon colors and then compare our results to other common interpolation and extrapolation methods. When the photometric filters and spectra overlap, we show that the error in the estimated spectra is reduced by more than 65% compared to the more commonly used techniques. We also show an expansion of the method to wavelengths beyond the range of the photometric filters. Finally, we demonstrate the usefulness of our technique by generating 50 additional SED templates from an original set of 10 and by applying the new set to photometric redshift estimation. We are able to reduce the photometric redshifts standard deviation by at least 22.0% and the outlier rejected bias by over 86.2% compared to original set for z ≤ 3.

  2. The Vibrational Spectra of the Boron Halides and their Molecular ...

    African Journals Online (AJOL)

    Two conformers, an eclipsed and a staggered species, have been examined for each complex. In the case of the boron trifluoride-water complex, the spectra computed using the largest basis set have been compared with the spectra obtained experimentally in nitrogen, argon and neon matrices at cryogenic temperatures.

  3. Experimental verification and analytical approach to cogging torque calculation and reduction of permanent magnet generators with multipole rotor for wind power applications

    Science.gov (United States)

    Choi, Jang-Young; Jang, Seok-Myeong

    2008-04-01

    This paper deals with the experimental verification and analytical approach to cogging torque calculation and reduction of permanent magnet generators (PMGs) with multipole rotor for wind power applications. Using energy methods with Fourier series expansion, cogging torque is analytically determined with air-gap flux density due to permanent magnets (PMs) and two-dimensional permeance function. The analytical results are validated extensively by nonlinear finite element (FE) results for various values of pole arc ratio (αp) of PMs. It shows that there exists optimum αp which minimizes cogging torque. However, we confirm that measured value for cogging torque of the PMG with optimum αp is twice higher than predicted value. The reason for an error between measured and predicted cogging torques is discussed fully in terms of a shape of PMs and is proved experimentally. The influence of stator skew on cogging torque is also presented using analytical, nonlinear FE and experimental methods.

  4. Experimental and numerical study of impact of voltage fluctuate, flicker and power factor wave electric generator to local distribution

    Science.gov (United States)

    Hadi, Nik Azran Ab; Rashid, Wan Norhisyam Abd; Hashim, Nik Mohd Zarifie; Mohamad, Najmiah Radiah; Kadmin, Ahmad Fauzan

    2017-10-01

    Electricity is the most powerful energy source in the world. Engineer and technologist combined and cooperated to invent a new low-cost technology and free carbon emission where the carbon emission issue is a major concern now due to global warming. Renewable energy sources such as hydro, wind and wave are becoming widespread to reduce the carbon emissions, on the other hand, this effort needs several novel methods, techniques and technologies compared to coal-based power. Power quality of renewable sources needs in depth research and endless study to improve renewable energy technologies. The aim of this project is to investigate the impact of renewable electric generator on its local distribution system. The power farm was designed to connect to the local distribution system and it will be investigated and analyzed to make sure that energy which is supplied to customer is clean. The MATLAB tools are used to simulate the overall analysis. At the end of the project, a summary of identifying various voltage fluctuates data sources is presented in terms of voltage flicker. A suggestion of the analysis impact of wave power generation on its local distribution is also presented for the development of wave generator farms.

  5. Tunneling spectra of graphene on copper unraveled

    DEFF Research Database (Denmark)

    Zhang, Xin; Stradi, Daniele; Liu, Lei

    2016-01-01

    mechanisms, etc. The interpretation of the spectra can be complicated, however. Specifically for graphene grown on copper, there have been conflicting reports of tunneling spectra. A clear understanding of the mechanisms behind the variability is desired. In this work, we have revealed that the root cause...... of the variability in tunneling spectra is the variation in graphene-substrate coupling under various experimental conditions, providing a salutary perspective on the important role of 2D material-substrate interactions. The conclusions are drawn from measured data and theoretical calculations for monolayer, AB......-stacked bilayer, and twisted bilayer graphene coexisting on the same substrates in areas with and without intercalated oxygen, demonstrating a high degree of consistency. The Van Hove singularities of the twisted graphene unambiguously indicate the Dirac energy between them, lending strong evidence to our...

  6. Experimental and simulation studies of neutron-induced single-event burnout in SiC power diodes

    Science.gov (United States)

    Shoji, Tomoyuki; Nishida, Shuichi; Hamada, Kimimori; Tadano, Hiroshi

    2014-01-01

    Neutron-induced single-event burnouts (SEBs) of silicon carbide (SiC) power diodes have been investigated by white neutron irradiation experiments and transient device simulations. It was confirmed that a rapid increase in lattice temperature leads to formation of crown-shaped aluminum and cracks inside the device owing to expansion stress when the maximum lattice temperature reaches the sublimation temperature. SEB device simulation indicated that the peak lattice temperature is located in the vicinity of the n-/n+ interface and anode contact, and that the positions correspond to a hammock-like electric field distribution caused by the space charge effect. Moreover, the locations of the simulated peak lattice temperature agree closely with the positions of the observed destruction traces. Furthermore, it was theoretically demonstrated that the period of temperature increase of a SiC power device is two orders of magnitude less than that of a Si power device, using a thermal diffusion equation.

  7. Comparison Between Numerical Modeling and Experimental Testing of a Point Absorber WEC Using Linear Power Take-Off System

    DEFF Research Database (Denmark)

    Zurkinden, Andrew Stephen; Kramer, Morten; Sichani, Mahdi Teimouri

    2012-01-01

    systems into a central wave to wire model. The power production then depends on the control strategy which is applied to the device. The objective of this paper is to develop numerical methods for motion analysis of marine structures with a special emphasis on wave energy converters. Two different time......Currently, a number of wave energy converters are being analyzed by means of numerical models in order to predict the electrical power generation under given wave conditions. A common characteristic of this procedure is to integrate the loadings from the hydrodynamics, power take-off and mooring...... domain models are applied to a point absorber system working in pitch mode only. The device is similar to the well-known Wavestar prototype located in the Danish North Sea. A laboratory model has been set up in order to validate the numerical simulations of the dynamics. Wave Excitation force...

  8. Experimental Investigation on the Feasibility of Using a Fresnel Lens as a Solar-Energy Collection System for Enhancing On-Orbit Power Generation Performance

    Directory of Open Access Journals (Sweden)

    Tae-Yong Park

    2017-01-01

    Full Text Available Cube satellites have a limitation for generating power because of their cubic structure and extremely small size. In addition, the incidence angle between the sun and the solar panels continuously varies owing to the revolution and rotation of the satellite according to the attitude control strategy. This angle is an important parameter for determining the power generation performance of the cube satellite. In this study, we performed an experimental feasibility study that uses a Fresnel lens as a solar-energy collection system for cube satellite applications, so that the power generation efficiency can be enhanced under the worst incidence angle condition between the sun and solar panels by concentrating and redirecting solar energy onto the solar panels with a commercial Fresnel lens. To verify the effectiveness of the proposed system, we conducted a power-measurement test using a solar simulator and Fresnel lenses at various angles to the light source. In addition, we predicted the on-orbit power-generation enhancement achieved by employing the solar-energy collection system with various attitude control strategies.

  9. Experimental Verification on Remote Detectability of Concealed Radioactive Material Based on the Plasma Discharge Delay Time using High-Power Millimeter-Wave

    Science.gov (United States)

    Kim, Dongsung; Yu, Dongho; Sawant, Ashwini; Choe, Mun Seok; Lee, Ingeun; Choi, Eunmi

    2016-10-01

    We experimentally demonstrate a remote detection method of a radioactive source by plasma breakdown using high-power millimeter-wave source, gyrotron. A number of free electrons near the radioactive source are much higher than those of without the radioactive source (roughly 10 particles/cm3) owing to the interaction of air molecules and strong gamma rays generated by radioactive material. The RF wave beam is focused in ambient air, and the plasmas discharge occurs involving random delay time which means a time interval between the RF wave and a fluorescent light caused by the plasma. We observed that the delay time decreased significantly due to the high density of free electrons in Ar plasma with an existence of Co60 radioactive material. This technique of delay time measurement shows 1000 times more sensitive than a method of detectable mass equation to identify the existence of radioactive source remotely. It is the first experimental verification of radioactive material detection using a high power gyrotron. This study shows that a remote detection of radioactive material based on analysis of precise delay time measurement could be feasible by using a high power millimeter/THz wave gyrotron. NRF-2013R1A1A2061062, NRF-2012-Global Ph.D. Fellowship Program.

  10. Simulation and experimental investigation of a high-Temperature superconducting inductive pulsed power supply with time delay effect of the secondary side

    Science.gov (United States)

    Dong, Liang; Xu, Qingying; Lu, Falong; Nie, Xinyi; He, Yingda; Wang, Yu; Yan, Zhongming

    2017-10-01

    In this paper, to obtain a higher amplitude, higher energy transfer efficiency and better waveform quality of pulse current, a pulsed power supply that has time delay effect of the secondary side and the structure of inductive and capacitive hybrid energy storage is presented. The discharge circuit of power supply is improved and its principles and working processes are firstly analyzed. Besides, simulations and experiments are conducted for verification of the principles. It is found that, under the same experimental conditions, when delay time is 1 ms, the amplitude of pulse current is increased from 2769A to 3185A; and the energy transfer efficiency from the primary to secondary side is improved from 57.75% to 58.2%; the quality of pulse waveform is improved clearly compared with that of traditional discharge circuit. The aforementioned three aspects are compared comprehensively, which proves the feasibility and advantages of the improved discharge circuit. In Addition, the analysis of experimental results reveals the controllability of the proposed pulsed power supply, with which the continuous variation of the amplitude of pulsed current within limits can be realized.

  11. Experimental validation of easy algebraic models for power estimation of PV modules; Validacion experimental de metodos algebraicos sencillos de estimacion de la potencia maxima de modulos fotovoltaicos de siclicio cristalinoa Sol real

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, C. M.; Aguilera, T. J.; Nofuentes, G. G.; Alvarez, E. M.; Castro, G. M. A.

    2004-07-01

    From electrical parameters of a PV module measured in conditions referred to as standard test conditions (STC, or standard reporting conditions, SRC) it is possible to predict its behaviour under natural sunlight, through numerical or algebraic methods. Some simple algebraic methods are experimentally compared in this work. Eventually, it is determined the method that fits best the empirical data concerning maximum power and energy yield of a calibrated m-Si PV module sited in the city of Jaen (Spain) from October 2003 to May 2004. (Author)

  12. Control spectra for Quito

    Science.gov (United States)

    Aguiar, Roberto; Rivas-Medina, Alicia; Caiza, Pablo; Quizanga, Diego

    2017-03-01

    The Metropolitan District of Quito is located on or very close to segments of reverse blind faults, Puengasí, Ilumbisí-La Bota, Carcelen-El Inca, Bellavista-Catequilla and Tangahuilla, making it one of the most seismically dangerous cities in the world. The city is divided into five areas: south, south-central, central, north-central and north. For each of the urban areas, elastic response spectra are presented in this paper, which are determined by utilizing some of the new models of the Pacific Earthquake Engineering Research Center (PEER) NGA-West2 program. These spectra are calculated considering the maximum magnitude that could be generated by the rupture of each fault segment, and taking into account the soil type that exists at different points of the city according to the Norma Ecuatoriana de la Construcción (2015). Subsequently, the recurrence period of earthquakes of high magnitude in each fault segment is determined from the physical parameters of the fault segments (size of the fault plane and slip rate) and the pattern of recurrence of type Gutenberg-Richter earthquakes with double truncation magnitude (Mmin and Mmax) is used.

  13. Photoemission spectra of charge density wave states in cuprates

    Science.gov (United States)

    Tu, Wei-Lin; Chen, Peng-Jen; Lee, Ting-Kuo

    Angle-resolved photoemission spectroscopy(ARPES) experiments have reported many exotic properties of cuprates, such as Fermi arc at normal state, two gaps at superconducting state and particle-hole asymmetry at the antinodal direction. On the other hand, a number of inhomogeneous states or so-called charge density waves(CDW) states have also been discovered in cuprates by many experimental groups. The relation between these CDW states and ARPES spectra is unclear. With the help of Gutzwiller projected mean-field theory, we can reproduce the quasiparticle spectra in momentum space. The spectra show strong correspondence to the experimental data with afore-mentioned exotic features in it.

  14. Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

    OpenAIRE

    J. A. Olorunmaiye; O. O. Awolola; J. F. Oladiji

    2012-01-01

    One of the manifestations of climate change is increase.in ambient air temperature usually referred to as global warming. For sustainable development in a country, there is need to identify impacts of climate change and the necessary adaptation and mitigation strategies to adopt. To simulate the effect of global warming on the power consumption of refrigerators, a (model No. 150) THERMOCOOL refrigerator filled with twenty-five 750cl packaged water bottleswas run in an air-conditioned room, in...

  15. Design, characterization and experimental validation of a compact, flexible pulsed power architecture for ex vivo platelet activation.

    Directory of Open Access Journals (Sweden)

    Allen L Garner

    Full Text Available Electric pulses can induce various changes in cell dynamics and properties depending upon pulse parameters; however, pulsed power generators for in vitro and ex vivo applications may have little to no flexibility in changing the pulse duration, rise- and fall-times, or pulse shape. We outline a compact pulsed power architecture that operates from hundreds of nanoseconds (with the potential for modification to tens of nanoseconds to tens of microseconds by modifying a Marx topology via controlling switch sequences and voltages into each capacitor stage. We demonstrate that this device can deliver pulses to both low conductivity buffers, like standard pulsed power supplies used for electroporation, and higher conductivity solutions, such as blood and platelet rich plasma. We further test the effectiveness of this pulse generator for biomedical applications by successfully activating platelets ex vivo with 400 ns and 600 ns electric pulses. This novel bioelectrics platform may provide researchers with unprecedented flexibility to explore a wide range of pulse parameters that may induce phenomena ranging from intracellular to plasma membrane manipulation.

  16. Design, characterization and experimental validation of a compact, flexible pulsed power architecture for ex vivo platelet activation.

    Science.gov (United States)

    Garner, Allen L; Caiafa, Antonio; Jiang, Yan; Klopman, Steve; Morton, Christine; Torres, Andrew S; Loveless, Amanda M; Neculaes, V Bogdan

    2017-01-01

    Electric pulses can induce various changes in cell dynamics and properties depending upon pulse parameters; however, pulsed power generators for in vitro and ex vivo applications may have little to no flexibility in changing the pulse duration, rise- and fall-times, or pulse shape. We outline a compact pulsed power architecture that operates from hundreds of nanoseconds (with the potential for modification to tens of nanoseconds) to tens of microseconds by modifying a Marx topology via controlling switch sequences and voltages into each capacitor stage. We demonstrate that this device can deliver pulses to both low conductivity buffers, like standard pulsed power supplies used for electroporation, and higher conductivity solutions, such as blood and platelet rich plasma. We further test the effectiveness of this pulse generator for biomedical applications by successfully activating platelets ex vivo with 400 ns and 600 ns electric pulses. This novel bioelectrics platform may provide researchers with unprecedented flexibility to explore a wide range of pulse parameters that may induce phenomena ranging from intracellular to plasma membrane manipulation.

  17. Experimental study on solar-powered adsorption refrigeration cycle with activated alumina and activated carbon as adsorbent

    Directory of Open Access Journals (Sweden)

    Himsar Ambarita

    2016-03-01

    Full Text Available Typical adsorbent applied in solar-powered adsorption refrigeration cycle is activated carbon. It is known that activated alumina shows a higher adsorption capacity when it is tested in the laboratory using a constant radiation heat flux. In this study, solar-powered adsorption refrigeration cycle with generator filled by different adsorbents has been tested by exposing to solar radiation in Medan city of Indonesia. The generator is heated using a flat-plate type solar collector with a dimension of 0.5 m×0.5 m. Four cases experiments of solar-powered adsorption cycle were carried out, they are with generator filled by 100% activated alumina (named as 100AA, by a mixed of 75% activated alumina and 25% activated carbon (75AA, by a mixed of 25% activated alumina and 75% activated carbon (25AA, and filled by 100% activated carbon. Each case was tested for three days. The temperature and pressure history and the performance have been presented and analyzed. The results show that the average COP of 100AA, 75AA, 25AA, and 100AC is 0.054, 0.056, 0.06, and 0.074, respectively. The main conclusion can be drawn is that for Indonesian condition and flat-plate type solar collector the pair of activated carbon and methanol is the better than activated alumina.

  18. Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

    Directory of Open Access Journals (Sweden)

    J. A. Olorunmaiye

    2012-12-01

    Full Text Available One of the manifestations of climate change is increase.in ambient air temperature usually referred to as global warming. For sustainable development in a country, there is need to identify impacts of climate change and the necessary adaptation and mitigation strategies to adopt. To simulate the effect of global warming on the power consumption of refrigerators, a (model No. 150 THERMOCOOL refrigerator filled with twenty-five 750cl packaged water bottleswas run in an air-conditioned room, in a room with the air-conditioner switched off and near an oven in a bakery. The electric power consumption of the refrigerator was measured using "Watts up?.net" Watt meter and the ambient temperature was measured using FLUKE temperature/humidity meter. The average hourly energy consumption of the refrigerator operating at mean ambient temperatures of 25.4°C, 30.7oC, 38.8°C were 93.844 Wh, 100.32 Wh and 105.08 Wh respectively. Some possible ways to reduce the increase in power consumption of refrigerators due to global warming include using compressors of higher efficiency and condensers of greater effectiveness.

  19. An experimental study on the combustion characteristics of a catalytic combustor for an MCFC power generation system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dong Jin [Hyosung Corporation, Sejong (Korea, Republic of); Ahn, Kook Young [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Kim, Man Young [Chonbuk Nat' l Univ., Jeonju (Korea, Republic of)

    2012-04-15

    In the MCFC power generation system, the combustor supplies a high temperature mixture of gases to the cathode and heat to the reformer by using the off gas from the anode; the off gas includes high concentrations of H{sub 2}O and CO{sub 2}. Since a combustor needs to be operated in a very lean condition and avoid local heating, a catalytic combustor is usually adopted. Catalytic combustion is also generally accepted as one of the environmentally preferred alternatives for generation of heat and power from fossil fuels because of its complete combustion and low emissions of pollutants such as CO, UHC, and NO{sub x}. In this study, experiments were conducted on catalytic combustion behavior in the presence of Pd based catalysts for the BOP (Balance Of Plant) of 5kW MCFC (Molten Carbonate Fuel Cell) power generation systems. Extensive investigations were carried out on the catalyst performance with the gaseous CH{sub 4} fuel by changing such various parameters as H{sub 2} addition, inlet temperature, excess air ratio, space velocity, catalyst type, and start up schedule of the pilot system adopted in the BOP.

  20. An experimental study of sampling time effects on the resolving power of on-line two-dimensional high performance liquid chromatography.

    Science.gov (United States)

    Huang, Yuan; Gu, Haiwei; Filgueira, Marcelo; Carr, Peter W

    2011-05-20

    The experimental effects of sampling time on the resolving power of on-line LC×LC were investigated. The first dimension gradient time ((1)t(g)) and sampling time (t(s)) were systematically varied ((1)t(g)=5, 12, 24 and 49 min; t(s)=6, 12, 21 and 40s). The resolving power of on-line LC×LC was evaluated in terms of two metrics namely the numbers of observed peaks and the effective 2D peak capacities obtained in separations of extracts of maize seeds. The maximum effective peak capacity and number of observed peaks of LC×LC were achieved at sampling times between 12 and 21s, at all first dimension gradient times. In addition, both metrics showed that the "crossover" time at which fully optimized 1DLC and LC×LC have equal resolving power varied somewhat with sampling time but is only about 5 min for sampling times of 12 and 21s. The longest crossover time was obtained when the sampling time was 6s. Furthermore, increasing the first dimension gradient time gave large improvements in the resolving power of LC×LC relative to 1DLC. Finally, comparisons of the corrected and effective 2D peak capacities as well as the number of peaks observed showed that the impact of the coverage factor is quite significant. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. PowerPoint: Time-Flow Photography: Experimental Imagery with Continuous Motion and Long Shutter Speeds by Rick Doble

    OpenAIRE

    Doble, Rick

    2014-01-01

    For the first time in the history of photography, digital photographers can now experiment with photographic effects and immediately review the results. This capability, which is crucial for experimentation, opens up a new world of imagery with slow shutter speeds that 'paint' light in a variety of ways. Yet some people believe that the effects of movement in slow-exposure photography are about the same and accidental. Nothing could be further from the truth. There is a quite sophisticated vo...

  2. Understanding the baryon and meson spectra

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, Michael R. [JLAB

    2013-10-01

    A brief overview is given of what we know of the baryon and meson spectra, with a focus on what are the key internal degrees of freedom and how these relate to strong coupling QCD. The challenges, experimental, theoretical and phenomenological, for the future are outlined, with particular reference to a program at Jefferson Lab to extract hadronic states in which glue unambiguously contributes to their quantum numbers.

  3. Experimental Evaluation of Inlet Distortion on an Ejector Powered Hybrid Wing Body at Take-off and Landing Conditions

    Science.gov (United States)

    Carter, Melissa B.; Shea, Patrick R.; Flamm, Jeffrey D.; Schuh, Michael; James, Kevin D.; Sexton, Matthew R.; Tompkins, Daniel M.; Beyar, Michael D.

    2016-01-01

    As part of the NASA Environmentally Responsible Aircraft project, an ultra high bypass ratio engine integration on a hybrid wing body demonstration was planned. The goal was to include engine and airframe integration concepts that reduced fuel consumption by at least 50% while still reducing noise 42 db cumulative on the ground. Since the engines would be mounted on the upper surface of the aft body of the aircraft, the inlets may be susceptible to vortex ingestion from the wing leading edge at high angles of attack and sideslip, and separated wing/body flow. Consequently, experimental and computational studies were conducted to collect flow surveys useful for characterizing engine operability. The wind tunnel tests were conducted at two NASA facilities, the 14- by 22-foot at NASA Langley and the 40- by 80-foot at NASA Ames Research Center. The test results included in this paper show that the distortion and pressure recovery levels were acceptable for engine operability. The CFD studies conducted to compare to experimental data showed excellent agreement for the angle of attacks examined, although failed to match the low speed experimental data at high sideslip angles.

  4. FY2017 Final Report: Power of the People: A technical ethical and experimental examination of the use of crowdsourcing to support international nuclear safeguards verification.

    Energy Technology Data Exchange (ETDEWEB)

    Gastelum, Zoe Nellie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sentz, Kari [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swanson, Meili Claire [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rinaudo, Cristina [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-01

    Recent advances in information technology have led to an expansion of crowdsourcing activities that utilize the “power of the people” harnessed via online games, communities of interest, and other platforms to collect, analyze, verify, and provide technological solutions for challenges from a multitude of domains. To related this surge in popularity, the research team developed a taxonomy of crowdsourcing activities as they relate to international nuclear safeguards, evaluated the potential legal and ethical issues surrounding the use of crowdsourcing to support safeguards, and proposed experimental designs to test the capabilities and prospect for the use of crowdsourcing to support nuclear safeguards verification.

  5. BACKGROUNDS OF EXPERIMENTAL INVESTIGATION OF ELECTROMAGNETIC COMPATIBILITY OF TRACTION ASYNCHRONOUS ELECTRIC DRIVES IN THE STRUCTURE OF DC TRACTION POWER SUPPLY SYSTEM

    Directory of Open Access Journals (Sweden)

    YU. S. Bondarenko

    2014-04-01

    Full Text Available Purpose. Application of physical modeling as a tool for research of any events or systems is becoming more widespread, including the field of railway transport. At the same time the adequacy of results that can be obtained, depends largely on the similarity degree of the physical model to real system. From the standpoint of the traction asynchronous electric drive (TAED research together with the traction power supply system research, the similarity can not be determined by the direct proportion of the parameters, because the processes nature accompanying the operation of these systems is non-linear. These features should be taken into account in the experimental setup, the basis for constructing of which is establishing of the system similarity that defines the purpose of this paper. Methodology. At the heart of the experimental setup creation laid reproduction of processes of energy transformation in the system of the DC traction power supply. Determination of the similarity degree of the proposed facility to the real system was carried out using the basic theorems of the similarity theory, their additional provisions on the complexity and nonlinear systems, as well as elements of mathematical analysis. Findings. According to the results of work: 1 The block diagram, the energy conversion mechanism of which is similar to the real system was received. This scheme is the basis of experimental setup, built in the future for the study of electromagnetic compatibility of TAED in the structure of DC traction electric power supply system. 2 Similarity of obtained structural scheme with the real system with the mechanism definition of calculating the scaling relations was established. Originality. In the process of establishing the similarity a simplified method for determining the scaling relations for nonlinear systems was suggested. They are identical in their structure components, but have different capacities. Practical value. Experimental

  6. EXPERIMENTAL STUDIES FOR DEVELOPMENT HIGH-POWER AUDIO SPEAKER DEVICES PERFORMANCE USING PERMANENT NdFeB MAGNETS SPECIAL TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Constantin D. STĂNESCU

    2013-05-01

    Full Text Available In this paper the authors shows the research made for improving high-power audio speaker devices performance using permanent NdFeB magnets special technology. Magnetic losses inside these audio devices are due to mechanical system frictions and to thermal effect of Joules eddy currents. In this regard, by special technology, were made conical surfaces at top plate and center pin. Analysing results obtained by modelling the magnetic circuit finite element method using electronic software package,was measured increase efficiency by over 10 %, from 1,136T to13T.

  7. Experimental evidence of the formation of a new chemical phase in a power ramped UO{sub 2} nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Desgranges, L., E-mail: lionel.desgranges@cea.fr; Lamontagne, J.; Riglet-Martial, Ch.; Blay, Th.

    2015-02-15

    We report for the first time the observation of γU{sub 4}O{sub 9} phase in a power ramped UO{sub 2} nuclear fuel. This phase is located within strips, a few microns wide, located at the position of the former grain boundaries at the periphery of the UO{sub 2} pellet. It has a high content in volatile fission products (Cs, I, Te) that diminish under high electron primary beam in EPMA. Thermochemical calculations allowed its identification as γU{sub 4}O{sub 9}.

  8. Experimental and theoretical studies of the VUV emission and absorption spectra of H{sub 2}, HD and D{sub 2} molecules; Etude experimentale et theorique des spectres d'emission et d'absorption VUV des molecules H{sub 2}, D{sub 2} et HD

    Energy Technology Data Exchange (ETDEWEB)

    Roudjane, M

    2007-12-15

    The aim of this thesis is to carry out an experimental study of the absorption and emission spectra of the D{sub 2} and HD isotopes, with high resolution, in the VUV domain and to supplement it by a theoretical study of the excited electronic states involved in the observed transitions. The emission spectra of HD and D{sub 2} are produced by Penning discharge source operating under low pressure and are recorded in the spectral range 78 - 170 nm. The recorded spectra contains more than 20.000 lines. The analysis of the spectrum consists in identifying and assigning the lines to the electronic transitions between energy levels of the molecule. The present analysis is based on our theoretical calculations of the ro-vibrational energy levels of the excited electronic states and the transition probabilities from these states towards the energy levels of the fundamental state. The theoretical results are obtained by resolving the coupled equations between the excited electronic states B{sup 1}{sigma}{sub u}{sup 1}, B'{sup 1}{sigma}{sub u}{sup 1}, C{sup 1}{pi}{sub u}{sup 1} and D{sup 1}{pi}{sub u}{sup 1}, taking into account the nonadiabatic couplings between these states, and they are obtained in the adiabatic approximation for the excited electronic states B''B-bar{sup 1}{sigma}{sub u}{sup +}, D'{sup 1}{pi}{sub u}{sup 1} and D''{sup 1}{pi}{sub u}{sup 1}. The equations are resolved using a modern method based on the discretization variables representation method. In addition, we have carried out a study of the absorption spectra of the HD and D{sub 2} molecules.

  9. Robust automated mass spectra interpretation and chemical formula calculation using mixed integer linear programming.

    Science.gov (United States)

    Baran, Richard; Northen, Trent R

    2013-10-15

    Untargeted metabolite profiling using liquid chromatography and mass spectrometry coupled via electrospray ionization is a powerful tool for the discovery of novel natural products, metabolic capabilities, and biomarkers. However, the elucidation of the identities of uncharacterized metabolites from spectral features remains challenging. A critical step in the metabolite identification workflow is the assignment of redundant spectral features (adducts, fragments, multimers) and calculation of the underlying chemical formula. Inspection of the data by experts using computational tools solving partial problems (e.g., chemical formula calculation for individual ions) can be performed to disambiguate alternative solutions and provide reliable results. However, manual curation is tedious and not readily scalable or standardized. Here we describe an automated procedure for the robust automated mass spectra interpretation and chemical formula calculation using mixed integer linear programming optimization (RAMSI). Chemical rules among related ions are expressed as linear constraints and both the spectra interpretation and chemical formula calculation are performed in a single optimization step. This approach is unbiased in that it does not require predefined sets of neutral losses and positive and negative polarity spectra can be combined in a single optimization. The procedure was evaluated with 30 experimental mass spectra and was found to effectively identify the protonated or deprotonated molecule ([M + H](+) or [M - H](-)) while being robust to the presence of background ions. RAMSI provides a much-needed standardized tool for interpreting ions for subsequent identification in untargeted metabolomics workflows.

  10. Experimental investigation and modelling of tritium washout by precipitation in the area of the nuclear power plant of Paks, Hungary.

    Science.gov (United States)

    Köllo, Z; Palcsu, L; Major, Z; Papp, L; Molnár, M; Ranga, T; Dombóvári, P; Manga, L

    2011-01-01

    Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate (3)He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to estimate the distribution of tritium around the plant. The model gives slightly higher concentrations than those measured in the field, but in general the agreement is satisfactory. The modelled values demonstrate that the effect of the plant on rainwater tritium levels is negligible over a distance of some kilometres. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Experimental Tests of Parameters Characterizing the Cooperation of Powered Roof Support Base and Floor of Low Bearing Capacity

    Science.gov (United States)

    Markowicz, Józef; Rajwa, Sylwester; Szweda, Stanisław

    2016-12-01

    Results of experimental tests aiming at determination of base pressure on the floor, carried out within "Geosoft" project, are presented. The tests included stand tests carried out with use of unique measuring instrumentation and special hydraulic cushion as well as tests of load of roof support set to load in operating longwall panel. The measurement results confirmed the necessity to consider the 3D model of cooperation of base and floor. Factors having impact on distribution of base pressure on the floor and its maximal value were identified, taking into account the test results.

  12. Power spectrum analysis for optical tweezers

    DEFF Research Database (Denmark)

    Berg-Sørensen, K.; Flyvbjerg, H.

    2004-01-01

    The force exerted by an optical trap on a dielectric bead in a fluid is often found by fitting a Lorentzian to the power spectrum of Brownian motion of the bead in the trap. We present explicit functions of the experimental power spectrum that give the values of the parameters fitted, including...... error bars and correlations, for the best such chi(2) fit in a given frequency range. We use these functions to determine the information content of various parts of the power spectrum, and find, at odds with lore, much information at relatively high frequencies. Applying the method to real data, we...... obtain perfect fits and calibrate tweezers with less than 1% error when the trapping force is not too strong. Relatively strong traps have power spectra that cannot be fitted properly with any Lorentzian, we find. This underscores the need for better understanding of the power spectrum than...

  13. Experimental variability and data pre-processing as factors affecting the discrimination power of some chemometric approaches (PCA, CA and a new algorithm based on linear regression) applied to (+/-)ESI/MS and RPLC/UV data: Application on green tea extracts.

    Science.gov (United States)

    Iorgulescu, E; Voicu, V A; Sârbu, C; Tache, F; Albu, F; Medvedovici, A

    2016-08-01

    The influence of the experimental variability (instrumental repeatability, instrumental intermediate precision and sample preparation variability) and data pre-processing (normalization, peak alignment, background subtraction) on the discrimination power of multivariate data analysis methods (Principal Component Analysis -PCA- and Cluster Analysis -CA-) as well as a new algorithm based on linear regression was studied. Data used in the study were obtained through positive or negative ion monitoring electrospray mass spectrometry (+/-ESI/MS) and reversed phase liquid chromatography/UV spectrometric detection (RPLC/UV) applied to green tea extracts. Extractions in ethanol and heated water infusion were used as sample preparation procedures. The multivariate methods were directly applied to mass spectra and chromatograms, involving strictly a holistic comparison of shapes, without assignment of any structural identity to compounds. An alternative data interpretation based on linear regression analysis mutually applied to data series is also discussed. Slopes, intercepts and correlation coefficients produced by the linear regression analysis applied on pairs of very large experimental data series successfully retain information resulting from high frequency instrumental acquisition rates, obviously better defining the profiles being compared. Consequently, each type of sample or comparison between samples produces in the Cartesian space an ellipsoidal volume defined by the normal variation intervals of the slope, intercept and correlation coefficient. Distances between volumes graphically illustrates (dis)similarities between compared data. The instrumental intermediate precision had the major effect on the discrimination power of the multivariate data analysis methods. Mass spectra produced through ionization from liquid state in atmospheric pressure conditions of bulk complex mixtures resulting from extracted materials of natural origins provided an excellent data

  14. Sequencing BPS spectra

    Energy Technology Data Exchange (ETDEWEB)

    Gukov, Sergei [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Max-Planck-Institut für Mathematik,Vivatsgasse 7, D-53111 Bonn (Germany); Nawata, Satoshi [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Centre for Quantum Geometry of Moduli Spaces, University of Aarhus,Nordre Ringgade 1, DK-8000 (Denmark); Saberi, Ingmar [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Stošić, Marko [CAMGSD, Departamento de Matemática, Instituto Superior Técnico,Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Mathematical Institute SANU,Knez Mihajlova 36, 11000 Belgrade (Serbia); Sułkowski, Piotr [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland)

    2016-03-02

    This paper provides both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explain from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincaré polynomials in numerous examples. Among these structural properties is a novel “sliding” property, which can be explained by using (refined) modular S-matrix. This leads to the identification of modular transformations in Chern-Simons theory and 3d N=2 theory via the 3d/3d correspondence. Lastly, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.

  15. Experimental tests about the cooling/freezing of the molten salts in the receiver tubes of a solar power plant with parabolic trough

    Science.gov (United States)

    Gaggioli, Walter; Fabrizi, Fabrizio; Rinaldi, Luca; Di Ascenzi, Primo

    2017-06-01

    In 2003 ENEA realized the PCS experimental Facility at Casaccia Research Centre (Rome, Italy), in order to test in real operating conditions the components of a parabolic trough solar plant, and to evaluate the technical feasibility of using the solar molten salts mixture (60% NaNO3, 40% KNO3, melting point 220÷240°C) in such a type of plant. ENEA also had the need to assess the behaviour of the solar receiver tubes during abnormal operating situations (wrong operation, pump block, power failure, etc.), when a block of the circulation of the molten salts may occur and cause the cooling or, worse, the freezing of the salts mixture inside the pipes. Some experimental tests have been performed, aimed to examine what happens in such a cases. In fact, without quick maneuvers to restart the circulation of the molten salts or to readily empty the receiver tubes, the molten salts contained in them may cool down to temperatures near/below the solidification. In this report are shown the results of the experimental tests carried out on the receiver tubes of the PCS Facility by cooling the process fluid down to temperatures near or below its freezing point. The tests show that the solidification of the salts does not damage the components of the plant but it is manageable and reversible, provided you apply the correct procedures.

  16. Remote sensing of stream flow rates - Correlation of meander and discharge spectra

    Science.gov (United States)

    Lingenfelter, R. E.; Schubert, G.

    1973-01-01

    Results of a study of river meander patterns and discharges, in which attempt was made to correlate the discharge spectrum of a river with the river meander power spectrum determined from aerial and satellite imagery. Some significant characteristics of both the discharge and the meander spectra have been discovered. Discharge frequency spectra based on long-term records of daily streamflow are found to have an inverse power-law dependence on discharge. This is shown to reflect the short-term decay of individual floods which are found to have an inverse power-law dependence on time. Meander power spectra for a number of river reaches, digitized from aerial photography, also show significant structure, the power spectral density having an inverse power-law dependence on wave number over one or more portions of the spectrum with breaks in the spectra at characteristic wave numbers. A number of examples of typical discharge and meander spectra are shown.

  17. New Experimental Characterisation Methods for Solid Biomass Fuels to be used in Combined Heat and Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Gunnar Eriksson, (Energy Engineering Div., Luleaa Univ. of Technology, S-971 87 Luleaa (Sweden)); Nordgren, Daniel; Berg, Magnus (Vattenfall Research and Development AB, S-814 26 Aelvkarleby (Sweden))

    2008-10-15

    The replacement of fossil fuels will lead to an increasing demand for unconventional biofuels. Fuel characterisation to predict combustion properties and facilitate the choice of combustion applications is important to avoid costly and time-consuming mistakes. Traditional methods are developed mainly for coal. Therefore procedures adapted specifically for solid biomass fuels are needed. This work is a survey on approaches for combustion characterisation of biomass developed during the last ten years. Innovative characterisation methods of interest concern: 1) Fuel handling behaviour: grindablility, erosion and abrasion properties. 2) Combustion characterisation: devolatilisation properties (important for ignition and flame stability), char burnout time. 3) Slagging and fouling properties of ash: ash particle formation, ash particle size distribution, ash composition, melting and gasification temperatures, slagging of bottom ash, reducing the risk by mixing with other fuels or using fuel additives and choice of suitable combustion applications for specific fuels. The main conclusions are: 1) a method to measure grindability which takes electric power consumption into account is needed as the Hardgrove Grindability Index used for coal grinding is pointless for biofuels, 2) there is a need to develop convenient low-cost methods to measure slagging and fouling tendencies, devolatilisation kinetics and char burnout for high heating rates found in fluidised beds and powder burners

  18. RF-MEMS for future mobile applications: experimental verification of a reconfigurable 8-bit power attenuator up to 110 GHz

    Science.gov (United States)

    Iannacci, J.; Tschoban, C.

    2017-04-01

    RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from  -10 dB to  -60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3-5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed.

  19. Experimental Investigation of Micrometer Scale Areal Density Variations in Metal Liners Driven by the 1 MA COBRA Pulsed Power Generator

    Science.gov (United States)

    Atoyan, Levon; Pikuz, Sergei; Shelkovenko, Tania; Hammer, David; Byvank, Tom

    2017-10-01

    On the 20 MA Z machine, the seed for the MRT instability was mitigated in the Magnetized Liner Inertial Fusion experiment using a thick dielectric coating. We have used high-resolution radiography to study the development of small-scale ( 10-30 μm) features in thin foils on the 1 MA, 100-200 ns COBRA pulsed power generator. We examined those features quantitatively in a 16 µm thick cylindrical Al liner, where we show areal density variation of up to 40-50%. We then show how the features' wavelength decreases when the material is changed from Al to Ni, Cu, and Ti, going from 21 +/-4 µm for Al to 11 +/-2 µm for Ti. Moreover, we show that expansion inhibition on both sides by dielectric material reduces small-scale feature size and density, and we show how pattern seeding can affect those parameters. This work is supported by the National Nuclear Security Administration Stewardship Sciences Academic Programs under Department of Energy Cooperative Agreement DE-NA0001836 as well as by the Department of Energy Grant Number DE-NA0002952.

  20. Excitation spectra of liquid iron up to superhigh temperatures

    Science.gov (United States)

    Fomin, Yu D.; Ryzhov, V. N.; Tsiok, E. N.; Brazhkin, V. V.

    2017-08-01

    Investigation of excitation spectra of liquids is one of the hot test topics nowadays. In particular, recent experimental works showed that liquid metals can demonstrate transverse excitations and positive sound dispersion. However, the theoretical description of these experimental observations is still missing. Here we report a molecular dynamics study of excitation spectra of liquid iron. We compare the results with available experimental data to justify the method. After that we perform calculations for high temperatures to find the location of the Frenkel line introduced in our previous works.

  1. High power 1 MeV neutral beam system and its application plan for the international tokamak experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hemsworth, R.S. [ITER Joint Central Team, Naka, Ibaraki (Japan)

    1997-03-01

    This paper describes the Neutral Beam Injection system which is presently being designed for the International Tokamak Experimental Reactor, ITER, in Europe Japan and Russia, with co-ordination by the Joint Central Team of ITER at Naka, Japan. The proposed system consists of three negative ion based neutral injectors, delivering a total of 50 MW of 1 MeV D{sup 0} to the ITER plasma for a pulse length of >1000 s. Each injectors uses a single caesiated volume arc discharge negative ion source, and a multi-grid, multi-aperture accelerator, to produce about 40 A of 1 MeV D{sup -}. This will be neutralized by collisions with D{sub 2} in a sub-divided gas neutralizer, which has a conversion efficiency of about 60%. The charged fraction of the beam emerging from the neutralizer is dumped in an electrostatic residual ion dump. A water cooled calorimeter can be moved into the beam path to intercept the neutral beam, allowing commissioning of the injector independent of ITER. ITER is scheduled to produce its first plasma at the beginning of 2008, and the planning of the R and D, construction and installation foresees the neutral injection system being available from the start of ITER operations. (author)

  2. Experimental Study of Hydraulic Control Rod Drive Mechanism for Passive IN-core Cooling System of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Kim, Kyung Mo; Jeong, Yeong Shin; Bang, In Cheol [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    CAREM 25 (27 MWe safety systems using hydraulic control rod drives (CRD) studied critical issues that were rod drops with interrupted flow [3]. Hydraulic control rod drive suggested fast shutdown condition using a large gap between piston and cylinder in order to fast drop of neutron absorbing rods. A Passive IN-core Cooling system (PINCs) was suggested for safety enhancement of pressurized water reactors (PWR), small modular reactor (SMR), sodium fast reactor (SFR) in UNIST. PINCs consist of hydraulic control rod drive mechanism (Hydraulic CRDM) and hybrid control rod assembly with heat pipe combined with control rod. The schematic diagram of the hydraulic CRDM for PINCs is shown in Fig. 1. The experimental results show the steady state and transient behavior of the upper cylinder at a low pressure and low temperature. The influence of the working fluid temperature and cylinder mass are investigated. Finally, the heat removal between evaporator section and condenser section is compared with or without the hybrid control rod. Heat removal test of the hybrid heat pipe with hydraulic CRDM system showed the heat transfer coefficient of the bundle hybrid control rod and its effect on evaporator pool. The preliminary test both hydraulic CRDM and heat removal system was conducted, which showed the possibility of the in-core hydraulic drive system for application of PINCs.

  3. Radial Flow in Non-Extensive Thermodynamics and Study of Particle Spectra at LHC in the Limit of Small $(q-1)$

    CERN Document Server

    Bhattacharyya, Trambak; Khuntia, Arvind; Pareek, Pooja; Sahoo, Raghunath

    2016-01-01

    We expand the Tsallis distribution in a Taylor series of powers of (q-1), where q is the Tsallis parameter, assuming q is very close to 1. This helps in studying the degree of deviation of transverse momentum spectra and other thermodynamic quantities from a thermalized Boltzmann distribution. After checking thermodynamic consistency, we provide analytical results for the Tsallis distribution in the presence of collective flow up to the first order of (q-1). The formulae are compared with the experimental data.

  4. Conformational analysis of a seven-membered ring azasugar, (3R,4R,6S)-trihydroxyazepane: Comparison of GIAO calculation and experimental NMR spectra on 13C chemical shifts

    Science.gov (United States)

    Yeh, Pao-Ling; Tai, Chin-Kuen; Shih, Tzenge-Lien; Hsiao, Hui-Ling; Wang, Bo-Cheng

    2012-06-01

    DFT/B3LYP/6-311++G(d,p) calculation of the relative stable conformations of (3R,4R,6S)-trihydroxyazepane are presented. The GIAO/DFT/OPBE, GIAO/DFT/B3LYP and GIAO/HF single point calculations with 6-311++G(d,p), 6-311+G(2d,p), cc-pVDZ and cc-pVTZ basis sets of (3R,4R,6S)-trihydroxyazepane were conducted to generate their 13C NMR chemical shifts. According to calculation results, 14 (3R,4R,6S)-trihydroxyazepane with optimized structure were generated. There were three conformers which contain the intramolecular hydrogen bonding exhibit a lowest electronic energies and TCN1(eq) was the most stable conformer than others. Boltzmann weighting factor analysis exhibits that TCN1(eq), TCN3(eq) and TCN5(eq) dominate a major contribution among the 14 conformers. The individual calculated NMR results of TCN1(eq), TCN3(eq) and TCN5(eq) represents a quite close correlation with experimental data. Moreover, the experimental 13C NMR chemical shifts gave only the average contribution of all conformers. In our investigation, the calculated 13C NMR chemical shifts of mixture (3R,4R,6S)-trihydroxyazepane exhibit a good agreement with the experimental NMR data. Calculated NMR results of mixture (3R,4R,6S)-trihydroxyazepane conformers display a remarkable MAE and RMS improvement over that of each individual conformer. A good calculation method and basis set choice to evaluate the theoretical chemical shifts for these conformers is HF/cc-pVTZ.

  5. Recent results in stopping power for positive ions, and some critical comments

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Helmut, E-mail: helmut.paul@jku.a [Atomic and Surface Physics, Institute for Experimental Physics, Johannes Kepler University, Altenbergerstrasse 69, A-4040 Linz (Austria)

    2010-11-15

    An overview is given of developments in the field of stopping power during the last few years, with particular emphasis on cases that seem to require further work. We discuss experimental results showing that stopping power for low energy protons, in metals and insulators, is not necessarily proportional to velocity. We mention that there is no discrepancy between the mean ionization potential derived from optical data or from stopping power. The problem of the stopping power of liquid water is discussed, considering both experiment and theory, and we find that recent experimental results and one of the theories are apparently too low. We discuss various types of theories for stopping power. We stress that in analyzing bulk backscattering spectra for stopping power, a low energy limit of validity must be stated. Using statistical analysis of experimental data for heavy ions in elemental solids, we find that the ATIMA and SRIM programs and the Hubert table are best in different regions of specific energy.

  6. An experimental analysis of flow boiling and pressure drop in a brazed plate heat exchanger for organic Rankine cycle power systems

    DEFF Research Database (Denmark)

    Desideri, Adriano; Zhang, Ji; Kærn, Martin Ryhl

    2017-01-01

    Organic Rankine cycle power systems for low quality waste heat recovery applications can play a major role in achieving targets of increasing industrial processes efficiency and thus reducing the emissions of greenhouse gases. Low capacity organic Rankine cycle systems are equipped with brazed...... and pressure drop during vaporization at typical temperatures for low quality waste heat recovery organic Rankine cycle systems are presented for the working fluids HFC-245fa and HFO-1233zd. The experiments were carried out at saturation temperatures of 100°C, 115°C and 130°C and inlet and outlet qualities...... plate heat exchangers which allows for efficient heat transfer with a compact design. Accurate heat transfer correlations characterizing these devices are required from the design phase to the development of model-based control strategies. In this paper, the experimental heat transfer coefficient...

  7. A database of synthetic molecular spectra for astrophysical applications

    Science.gov (United States)

    Cami, J.; Markwick-Kemper, A. J.

    We present an online database of molecular template spectra for astrophysical purposes. The initial database contains over 100,000 individual template spectra for 42 molecules totalling 97 isotopomers, and we provide an interface to the calculation of more spectra tailored to users' individual needs. Normalized absorption spectra are calculated in the LTE limit and presented for a wide range of astrophysically relevant temperature and column density regimes. For the same parameters, pure emission spectra are also calculated. The template spectra can be retrieved at different instrumental resolving powers, and can be combined together with different abundances interactively. Users can request additional spectra to be calculated for other parameters, the results of which become part of the database. These template spectra will be useful for identification of molecular absorption and emission bands over a wide range of spectroscopic observations, and allow a first estimate of temperatures and column densities in the regions where the molecular bands are formed. We highlight the different applications for which we believe this database and service to be useful, and offer some examples of how the templates can be used in various astrophysical contexts, and in particular for the analyis of observations with ISO and Spitzer.

  8. Deconvolution procedure of the UV-vis spectra. A powerful tool for the estimation of the binding of a model drug to specific solubilisation loci of bio-compatible aqueous surfactant-forming micelle.

    Science.gov (United States)

    Calabrese, Ilaria; Merli, Marcello; Turco Liveri, Maria Liria

    2015-05-05

    UV-vis-spectra evolution of Nile Red loaded into Tween 20 micelles with pH and [Tween 20] have been analysed in a non-conventional manner by exploiting the deconvolution method. The number of buried sub-bands has been found to depend on both pH and bio-surfactant concentration, whose positions have been associated to Nile Red confined in aqueous solution and in the three micellar solubilisation sites. For the first time, by using an extended classical two-pseudo-phases-model, the robust treatment of the spectrophotometric data allows the estimation of Nile Red binding constant to the available loci. Hosting capability towards Nile Red is exalted by the pH enhancement. Comparison between binding constant values classically evaluated and those estimated by the deconvolution protocol unveiled that overall binding values perfectly match with the mean values of the local binding sites. This result suggests that deconvolution procedure provides more precise and reliable values, which are more representative of drug confinement. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Influence of the experimental program of trainings in armsport on the power indexes of basic muscle groups of 16-17-years-old armwrestlers

    Directory of Open Access Journals (Sweden)

    Kamaev O. I.

    2013-01-01

    Full Text Available The features of influence of the experimental program of trainings are considered in armsport. The program is developed taking into account age-dependent changes in the organism of young sportsmen, features of development of force and power endurance, structure of long-term preparation. The program is directed on development of force and static power endurance of basic muscle groups of sportsmen. In researches took part 30 sportsmen aged 16-17 years old. It is set that the stage of the specialized base training is foreseen by the increase of time on perfection of technique of fight at the table to 15 %. The special attention must be spared the special physical youth development. The block of the specialized training to send to development of explosive force, workings of weak corners, change of character of work is recommended. It is set that trainings with the static loadings are obligatory and in the general volume of loadings must make no less than 20 %. It is necessarily necessary to plan the block of the restoration training for physical and psychological renewal of sportsmen after the conducted setup time and appearance on competitions, exposure and comprehension of sufferet errors and search of methods of their removal.

  10. "Parallel factor analysis of multi-excitation ultraviolet resonance Raman spectra for protein secondary structure determination".

    Science.gov (United States)

    Oshokoya, Olayinka O; JiJi, Renee D

    2015-09-10

    Protein secondary structural analysis is important for understanding the relationship between protein structure and function, or more importantly how changes in structure relate to loss of function. The structurally sensitive protein vibrational modes (amide I, II, III and S) in deep-ultraviolet resonance Raman (DUVRR) spectra resulting from the backbone C-O and N-H vibrations make DUVRR a potentially powerful tool for studying secondary structure changes. Experimental studies reveal that the position and intensity of the four amide modes in DUVRR spectra of proteins are largely correlated with the varying fractions of α-helix, β-sheet and disordered structural content of proteins. Employing multivariate calibration methods and DUVRR spectra of globular proteins with varying structural compositions, the secondary structure of a protein with unknown structure can be predicted. A disadvantage of multivariate calibration methods is the requirement of known concentration or spectral profiles. Second-order curve resolution methods, such as parallel factor analysis (PARAFAC), do not have such a requirement due to the "second-order advantage." An exceptional feature of DUVRR spectroscopy is that DUVRR spectra are linearly dependent on both excitation wavelength and secondary structure composition. Thus, higher order data can be created by combining protein DUVRR spectra of several proteins collected at multiple excitation wavelengths to give multi-excitation ultraviolet resonance Raman data (ME-UVRR). PARAFAC has been used to analyze ME-UVRR data of nine proteins to resolve the pure spectral, excitation and compositional profiles. A three factor model with non-negativity constraints produced three unique factors that were correlated with the relative abundance of helical, β-sheet and poly-proline II dihedral angles. This is the first empirical evidence that the typically resolved "disordered" spectrum represents the better defined poly-proline II type structure

  11. Development of methods for evaluation of electricity saving and load levelling measures. Part 3: Experimental assessment of the effect of a power conservation campaign

    Energy Technology Data Exchange (ETDEWEB)

    Aalborg Nielsen, H.; Madsen, H. [Danmarks Tekniske Univ., Dept. of Mathematical Modelling (Denmark)

    1997-12-01

    The purpose of the project described in this report is to develop and to investigate methods for estimating effects of power conservation campaigns, and to estimate the effect of a particular campaign. The statistical approach of experimental design, followed by analysis of measurements is applied. Using a method known as cluster analysis prior to the initiation of the campaign, a number of substations for which measurements equipment was installed were combined into groups of highest possible similarity with respect to a number of features. It was decided to perform a campaign on a total of two substations. For this purpose the two groups of highest similarity were selected and one substation was chosen from each group to receive the campaign (the active substations). Since each of the two groups contained two substations this procedure left two substations for comparisons (the control substations). The overall results indicate a 10-12% reduction of the power consumption when carrying out a campaign. However, some difference is observed for the two pairs of active and control substations. Consequently, the extrapolation to other substations of similar kind will be difficult. When measuring the diurnal profile as the relative deviation from the daily level during the cycle, practically no effect of the campaign can be detected. However, the amplitude of the profile measured in units of power consumption depends strongly on the daily level. It is demonstrated that non-parametric and semi non-parametric methods, combined with traditional time series analysis and bootstrapping, are well suited as statistical tools for the analysis of data from these kinds of experiments. (au) EFP-95. 22 refs.

  12. Boundary layer heights derived from velocity spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hoejstrup, J.; Barthelmie, R.J. [Risoe National Lab., Roskilde (Denmark); Kaellstrand, B. [Univ. of Uppsala, Uppsala (Sweden)

    1997-10-01

    It is a well-known fact that the height of the mixed layer determines the size of the largest and most energetic eddies that can be observed in the unstable boundary layer, and consequently a peak can be observed in the power spectra of the along-wind velocity component at scales comparable to the mixed layer depth. We will now show how the mixed layer depth can be derived from the u-specta and the results will be compared with direct measurements using pibal and tethersonde measurements. (au)

  13. Study of a Single-Power Two-Circuit ESR Process with Current-Carrying Mold: Mathematical Simulation of the Process and Experimental Verification

    Science.gov (United States)

    Dong, Yanwu; Hou, Zhiwen; Jiang, Zhouhua; Cao, Haibo; Feng, Qianlong; Cao, Yulong

    2017-12-01

    A novel single-power two-circuit ESR process (ESR-STCCM) with current-carrying mold has been investigated via numerical simulation and experimental research in this paper. A 2D quasi-steady-state mathematical model is developed to describe ESR-STCCM. The electromagnetic field, flow field, slag pool temperature distribution, and the shape of a molten steel pool in ESR-STCCM have been investigated by FLUENT software as well as user-defined functions (UDF). The results indicate that ESR-STCCM is different from the conventional ESR process. The maximum electromagnetic force, current density, Joule heat, and slag pool flow velocity are located in the lower part of the conductor in the ESR-STCCM process. The direction of the maximum electromagnetic force inclines upward. There are two distinct vortices in the slag pool. The larger swirl rotates counterclockwise near the conductor, with a value of 0.0263 m s-1 due to the interaction of the electromagnetic force and gravity. The maximum temperature of the slag pool is 2070 K (1797 °C) and is located in the center of the swirl with a filling ratio of 0.6 and a 20 mm electrode immersion depth. The depth of a molten steel pool is shallower, which is conducive to improving solidification quality. In addition, the filling ratio of 0.6 is conducive to controlling steel solidification quality. Some experiments have been done, and the numerical model is confirmed by experimental results.

  14. Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations

    Energy Technology Data Exchange (ETDEWEB)

    Rees, M. [Aerodyn Energiesysteme gmbH, Rendsburg (Germany)

    1996-09-01

    The Germanische Lloyd guideline allows calculations of load spectra in two fundamentally different ways. In the case of the so-called `simplified load spectra` the maximum amplitude of fluctuation of a load component is formed as {+-}75% of the average value of the purely aerodynamic loads of this component at rated wind conditions, together with an overlay of mass-related loads. The second method allowed in the GL guideline is the calculation of load spectra from simulation results in the time domain. For a number of average wind speeds the time-dependent characteristics of the load components are calculated taking account of the natural spatial turbulence of the wind. These are converted into load spectra using the rainflow method. In a parametric study the load spectra are calculated according to both methods and compared. The calculations are performed for turbines with rated powers of 100 kW to 2000 kW, with two and three blades, and also for stall-controlled and pitch-controlled turbines. The calculated load spectra are compared with each by means of 1 P fatigue equivalent load spectra. The influence of individual parameters is presented, as is the validity of the simplified load spectra. (au)

  15. The spectra and dynamics of diatomic molecules

    CERN Document Server

    Lefebvre-Brion, Helene

    2004-01-01

    This book is written for graduate students just beginning research, for theorists curious about what experimentalists actually can and do measure, and for experimentalists bewildered by theory. It is a guide for potential users of spectroscopic data, and uses language and concepts that bridge the frequency-and time-domain spectroscopic communities. Key topics, concepts, and techniques include: the assignment of simple spectra, basic experimental techniques, definition of Born-Oppenheimer and angular momentum basis sets and the associated spectroscopic energy level patterns (Hund's ca

  16. Interpreting peptide mass spectra by VEMS

    DEFF Research Database (Denmark)

    Mathiesen, Rune; Lundsgaard, M.; Welinder, Karen G.

    2003-01-01

    of peptide MS/MS spectra imported in text file format. Peaks are annotated, the monoisotopic peaks retained, and the b-and y-ion series identified in an interactive manner. The called peptide sequence is searched against a local protein database for sequence identity and peptide mass. The report compares...... the calculated and the experimental mass spectrum of the called peptide. The program package includes four accessory programs. VEMStrans creates protein databases in FASTA format from EST or cDNA sequence files. VEMSdata creates a virtual peptide database from FASTA files. VEMSdist displays the distribution...

  17. Copper(II) complex with 6-methylpyridine-2-carboxyclic acid: Experimental and computational study on the XRD, FT-IR and UV-Vis spectra, refractive index, band gap and NLO parameters.

    Science.gov (United States)

    Altürk, Sümeyye; Avcı, Davut; Başoğlu, Adil; Tamer, Ömer; Atalay, Yusuf; Dege, Necmi

    2018-02-05

    Crystal structure of the synthesized copper(II) complex with 6-methylpyridine-2-carboxylic acid, [Cu(6-Mepic)2·H2O]·H2O, was determined by XRD, FT-IR and UV-Vis spectroscopic techniques. Furthermore, the geometry optimization, harmonic vibration frequencies for the Cu(II) complex were carried out by using Density Functional Theory calculations with HSEh1PBE/6-311G(d,p)/LanL2DZ level. Electronic absorption wavelengths were obtained by using TD-DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level with CPCM model and major contributions were determined via Swizard/Chemissian program. Additionally, the refractive index, linear optical (LO) and non-nonlinear optical (NLO) parameters of the Cu(II) complex were calculated at HSEh1PBE/6-311G(d,p) level. The experimental and computed small energy gap shows the charge transfer in the Cu(II) complex. Finally, the hyperconjugative interactions and intramolecular charge transfer (ICT) were studied by performing of natural bond orbital (NBO) analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Stimulus dependence of local field potential spectra: experiment versus theory.

    Science.gov (United States)

    Barbieri, Francesca; Mazzoni, Alberto; Logothetis, Nikos K; Panzeri, Stefano; Brunel, Nicolas

    2014-10-29

    The local field potential (LFP) captures different neural processes, including integrative synaptic dynamics that cannot be observed by measuring only the spiking activity of small populations. Therefore, investigating how LFP power is modulated by external stimuli can offer important insights into sensory neural representations. However, gaining such insight requires developing data-driven computational models that can identify and disambiguate the neural contributions to the LFP. Here, we investigated how networks of excitatory and inhibitory integrate-and-fire neurons responding to time-dependent inputs can be used to interpret sensory modulations of LFP spectra. We computed analytically from such models the LFP spectra and the information that they convey about input and used these analytical expressions to fit the model to LFPs recorded in V1 of anesthetized macaques (Macaca mulatta) during the presentation of color movies. Our expressions explain 60%-98% of the variance of the LFP spectrum shape and its dependency upon movie scenes and we achieved this with realistic values for the best-fit parameters. In particular, synaptic best-fit parameters were compatible with experimental measurements and the predictions of firing rates, based only on the fit of LFP data, correlated with the multiunit spike rate recorded from the same location. Moreover, the parameters characterizing the input to the network across different movie scenes correlated with cross-scene changes of several image features. Our findings suggest that analytical descriptions of spiking neuron networks may become a crucial tool for the interpretation of field recordings. Copyright © 2014 the authors 0270-6474/14/3414589-17$15.00/0.

  19. Analysis of positron lifetime spectra in polymers

    Science.gov (United States)

    Singh, Jag J.; Mall, Gerald H.; Sprinkle, Danny R.

    1988-01-01

    A new procedure for analyzing multicomponent positron lifetime spectra in polymers was developed. It requires initial estimates of the lifetimes and the intensities of various components, which are readily obtainable by a standard spectrum stripping process. These initial estimates, after convolution with the timing system resolution function, are then used as the inputs for a nonlinear least squares analysis to compute the estimates that conform to a global error minimization criterion. The convolution integral uses the full experimental resolution function, in contrast to the previous studies where analytical approximations of it were utilized. These concepts were incorporated into a generalized Computer Program for Analyzing Positron Lifetime Spectra (PAPLS) in polymers. Its validity was tested using several artificially generated data sets. These data sets were also analyzed using the widely used POSITRONFIT program. In almost all cases, the PAPLS program gives closer fit to the input values. The new procedure was applied to the analysis of several lifetime spectra measured in metal ion containing Epon-828 samples. The results are described.

  20. Interpretation of wave energy spectra

    National Research Council Canada - National Science Library

    Thompson, E.F

    1980-01-01

    Guidelines for interpreting nondirectional wave energy spectra and presented. A simple method is given for using the spectrum to estimate a significant height and period for each major wave train in most sea states...

  1. Infrared spectra of mineral species

    CERN Document Server

    Chukanov, Nikita V

    2014-01-01

    This book details more than 3,000 IR spectra of more than 2,000 mineral species collected during last 30 years. It features full descriptions and analytical data of each sample for which IR spectrum was obtained.

  2. Pileup correction of microdosimetric spectra

    CERN Document Server

    Langen, K M; Lennox, A J; Kroc, T K; De Luca, P M

    2002-01-01

    Microdosimetric spectra were measured at the Fermilab neutron therapy facility using low pressure proportional counters operated in pulse mode. The neutron beam has a very low duty cycle (<0.1%) and consequently a high instantaneous dose rate which causes distortions of the microdosimetric spectra due to pulse pileup. The determination of undistorted spectra at this facility necessitated (i) the modified operation of the proton accelerator to reduce the instantaneous dose rate and (ii) the establishment of a computational procedure to correct the measured spectra for remaining pileup distortions. In support of the latter effort, two different pileup simulation algorithms using analytical and Monte-Carlo-based approaches were developed. While the analytical algorithm allows a detailed analysis of pileup processes it only treats two-pulse and three-pulse pileup and its validity is hence restricted. A Monte-Carlo-based pileup algorithm was developed that inherently treats all degrees of pileup. This algorithm...

  3. Photon spectra from WIMP annihilation

    OpenAIRE

    Ruiz Cembranos, José Alberto; Cruz Dombriz, Álvaro de la; Dobado González, Antonio; Lineros, R. A.; López Maroto, Antonio

    2010-01-01

    If the present dark matter in the Universe annihilates into standard model particles, it must contribute to the fluxes of cosmic rays that are detected on the Earth and, in particular, to the observed gamma-ray fluxes. The magnitude of such a contribution depends on the particular dark matter candidate, but certain features of the produced photon spectra may be analyzed in a rather model-independent fashion. In this work we provide the complete photon spectra coming from WIMP annihilation int...

  4. Correlating features in the primordial spectra

    CERN Document Server

    Achúcarro, Ana; Palma, Gonzalo A; Patil, Subodh P

    2013-01-01

    Heavy fields coupled to the inflaton reduce the speed of sound in the effective theory of the adiabatic mode each time the background inflationary trajectory deviates from a geodesic. This can result in features in the primordial spectra. We compute the corresponding bispectrum and show that if a varying speed of sound induces features in the power spectrum, the change in the bispectrum is given by a simple formula involving the change in the power spectrum and its derivatives. In this manner, we provide a uniquely discriminable signature of a varying sound speed for the adiabatic mode during inflation that indicates the influence of heavy fields. We find that features in the bispectrum peak in the equilateral limit and, in particular, in the squeezed limit we find considerable enhancement entirely consistent with the single field consistency relation. From the perspective of the underlying effective theory, our results generalize to a wide variety of inflationary models where features are sourced by the time...

  5. Automated detection of satellite contamination in incoherent scatter radar spectra

    Directory of Open Access Journals (Sweden)

    J. Porteous

    2003-05-01

    Full Text Available Anomalous ion line spectra have been identified in many experiments. Such spectra are defined as deviations from the standard symmetric "double-humped" spectra derived from incoherent scatter radar echoes from the upper atmosphere. Some anomalous spectra – where there are sharp enhancements of power over restricted height ranges – have been attributed to satellite contamination in the beam path. Here we outline a method for detecting such contamination, and review in detail a few cases where the method enables the identification of anomalous spectra as satellite echoes, subsequently ascribed to specific orbital objects. The methods used here to identify such satellites provide a useful way of distinguishing anomalous spectra due to satellites from those of geophysical origin. Analysis of EISCAT Svalbard Radar data reveals that an average of 8 satellites per hour are found to cross the beam. Based on a relatively small sample of the data set, it appears that at least half of the occurrences of anomalous spectra are caused by satellite contamination rather than being of geophysical origin.Key words. Ionosphere (auroral ionosphere, instruments and techniques – Radio Science (signal processing

  6. Experimentation of RT-LOTOS for a critical function of a power plant instrumentation and control system; Experimentation de RT-LOTOS pour une fonction critique d`un systeme de controle-commande en centrale

    Energy Technology Data Exchange (ETDEWEB)

    Andriantsiiferana, L.; Courtiat, J.P.; De Oliveira, R.C.

    1996-01-01

    This document is the final report of the contract between LAAS-CNRS and the EdF Direction of Researches and Studies about the experimentation of RT-LOTOS formal description technique on a critical function of a nuclear power plant instrumentation and control system. This report comprises 4 parts: part 1 describes the RT-LOTOS (Real Time-Language of Temporal Ordering Specifications) tutorial and its RTL tool environment, the different RT-LOTOS operators and semantics, and the RTL tool main functionalities; part 2 deals with the methodology and the global architecture for the specification and validation of the CCT (Central Calculator for Treatment); part 3 gives more details about the different processes identified in the specification architecture and presents the main results obtained for the validation of the nominal functioning; part 4 describes some exceptional situations and shows how some failures and their associated recovery mechanisms can be modelled. (J.S.). 6 refs., 53 figs., 5 tabs., 2 appends.

  7. VEGA: A low-power front-end ASIC for large area multi-linear X-ray silicon drift detectors: Design and experimental characterization

    Science.gov (United States)

    Ahangarianabhari, Mahdi; Macera, Daniele; Bertuccio, Giuseppe; Malcovati, Piero; Grassi, Marco

    2015-01-01

    We present the design and the first experimental characterization of VEGA, an Application Specific Integrated Circuit (ASIC) designed to read out large area monolithic linear Silicon Drift Detectors (SDD's). VEGA consists of an analog and a digital/mixed-signal section to accomplish all the functionalities and specifications required for high resolution X-ray spectroscopy in the energy range between 500 eV and 50 keV. The analog section includes a charge sensitive preamplifier, a shaper with 3-bit digitally selectable shaping times from 1.6 μs to 6.6 μs and a peak stretcher/sample-and-hold stage. The digital/mixed-signal section includes an amplitude discriminator with coarse and fine threshold level setting, a peak discriminator and a logic circuit to fulfill pile-up rejection, signal sampling, trigger generation, channel reset and the preamplifier and discriminators disabling functionalities. A Serial Peripherical Interface (SPI) is integrated in VEGA for loading and storing all configuration parameters in an internal register within few microseconds. The VEGA ASIC has been designed and manufactured in 0.35 μm CMOS mixed-signal technology in single and 32 channel versions with dimensions of 200 μm×500 μm per channel. A minimum intrinsic Equivalent Noise Charge (ENC) of 12 electrons r.m.s. at 3.6 μs peaking time and room temperature is measured and the linearity error is between -0.9% and +0.6% in the whole input energy range. The total power consumption is 481 μW and 420 μW per channel for the single and 32 channels version, respectively. A comparison with other ASICs for X-ray SDD's shows that VEGA has a suitable low noise and offers high functionality as ADC-ready signal processing but at a power consumption that is a factor of four lower than other similar existing ASICs.

  8. Validation of system codes RELAP5 and SPECTRA for natural convection boiling in narrow channels

    Energy Technology Data Exchange (ETDEWEB)

    Stempniewicz, M.M., E-mail: stempniewicz@nrg.eu; Slootman, M.L.F.; Wiersema, H.T.

    2016-10-15

    case of SPECTRA. Since the experimental uncertainty is 11%, the required safety margin is in this case 27% and 26% for RELAP and SPECTRA respectively. • The range within which both codes gave conservative results is: hydraulic diameters of 1.1 ⩽ D{sub hyd} ⩽ 2.0 mm, heated lengths of 0.5 ⩽ L ⩽ 1.0 m, pressures of 0.10 ⩽ P ⩽ 0.99 MPa. In this range the required safety margin is in this case 11%, due to experimental uncertainties. • The validation was performed using the standard version of the RELAP and SPECTRA codes. Calculations showed that burnout is caused in most cases by a complete dryout in the upper part of the cooling channel rather by exceeding CHF in two-phase flow situation. Therefore CHF correlation is in fact not affecting the results. • A new correlation is proposed that gives a conservative estimation of the heat flux at which burnout occurs. The correlation is similar to the Monde correlation and is based on global conditions (total power, length, diameter). It is not suitable for implementation into a thermal–hydraulic code, however, it is very convenient for a quick engineering check of margin to burnout.

  9. Excited state mass spectra of singly charmed baryons

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Zalak; Kumar Rai, Ajay [Sardar Vallabhbhai National Institute of Technology, Department of Applied Physics, Surat, Gujarat (India); Thakkar, Kaushal [GIDC Degree Engineering College, Department of Applied Sciences and Humanities, Abrama (India); Vinodkumar, P.C. [Sardar Patel University, Department of Physics, V.V. Nagar (India)

    2016-10-15

    Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of the three-body system. The baryons consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of the confinement potential is hyper-Coloumb plus power potential with potential index ν, varying from 0.5 to 2.0. The first-order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of Σ{sub c}{sup ++}, Σ{sub c}{sup +}, Σ{sub c}{sup 0}, Ξ{sub c}{sup +}, Ξ{sub c}{sup 0}, Λ{sub c}{sup +}, Ω{sub c}{sup 0} baryons, are reported in this paper. We have incorporated spin-spin, spin-orbit and tensor interactions perturbatively in the present study. The semi-electronic decay of Ω{sub c} and Ξ{sub c} are also calculated using the spectroscopic parameters of these baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. We also construct the Regge trajectory in (n{sub r},M{sup 2}) and (J,M{sup 2}) planes for these baryons. (orig.)

  10. Combined analysis of data from two granddaughter designs: A simple strategy for QTL confirmation and increasing experimental power in dairy cattle

    Directory of Open Access Journals (Sweden)

    Blümel Jürgen

    2003-05-01

    Full Text Available Abstract A joint analysis of five paternal half-sib Holstein families that were part of two different granddaughter designs (ADR- or Inra-design was carried out for five milk production traits and somatic cell score in order to conduct a QTL confirmation study and to increase the experimental power. Data were exchanged in a coded and standardised form. The combined data set (JOINT-design consisted of on average 231 sires per grandsire. Genetic maps were calculated for 133 markers distributed over nine chromosomes. QTL analyses were performed separately for each design and each trait. The results revealed QTL for milk production on chromosome 14, for milk yield on chromosome 5, and for fat content on chromosome 19 in both the ADR- and the Inra-design (confirmed within this study. Some QTL could only be mapped in either the ADR- or in the Inra-design (not confirmed within this study. Additional QTL previously undetected in the single designs were mapped in the JOINT-design for fat yield (chromosome 19 and 26, protein yield (chromosome 26, protein content (chromosome 5, and somatic cell score (chromosome 2 and 19 with genomewide significance. This study demonstrated the potential benefits of a combined analysis of data from different granddaughter designs.

  11. Improved quantitative analysis of spectra using a new method of obtaining derivative spectra based on a singular perturbation technique.

    Science.gov (United States)

    Li, Zhigang; Wang, Qiaoyun; Lv, Jiangtao; Ma, Zhenhe; Yang, Linjuan

    2015-06-01

    Spectroscopy is often applied when a rapid quantitative analysis is required, but one challenge is the translation of raw spectra into a final analysis. Derivative spectra are often used as a preliminary preprocessing step to resolve overlapping signals, enhance signal properties, and suppress unwanted spectral features that arise due to non-ideal instrument and sample properties. In this study, to improve quantitative analysis of near-infrared spectra, derivatives of noisy raw spectral data need to be estimated with high accuracy. A new spectral estimator based on singular perturbation technique, called the singular perturbation spectra estimator (SPSE), is presented, and the stability analysis of the estimator is given. Theoretical analysis and simulation experimental results confirm that the derivatives can be estimated with high accuracy using this estimator. Furthermore, the effectiveness of the estimator for processing noisy infrared spectra is evaluated using the analysis of beer spectra. The derivative spectra of the beer and the marzipan are used to build the calibration model using partial least squares (PLS) modeling. The results show that the PLS based on the new estimator can achieve better performance compared with the Savitzky-Golay algorithm and can serve as an alternative choice for quantitative analytical applications.

  12. Demonstrations of Optical Spectra with a Video Camera

    Science.gov (United States)

    Kraftmakher, Yaakov

    2012-01-01

    The use of a video camera may markedly improve demonstrations of optical spectra. First, the output electrical signal from the camera, which provides full information about a picture to be transmitted, can be used for observing the radiant power spectrum on the screen of a common oscilloscope. Second, increasing the magnification by the camera…

  13. QUALITATIVE INTERPRETATION OF GALAXY SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Almeida, J.; Morales-Luis, A. B. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Terlevich, R.; Terlevich, E. [Instituto Nacional de Astrofisica, Optica y Electronica, Tonantzintla, Puebla (Mexico); Cid Fernandes, R., E-mail: jos@iac.es, E-mail: abml@iac.es, E-mail: rjt@ast.cam.ac.uk, E-mail: eterlevi@inaoep.mx, E-mail: cid@astro.ufsc.br [Departamento de Fisica-CFM, Universidade Federal de Santa Catarina, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil)

    2012-09-10

    We describe a simple step-by-step guide to qualitative interpretation of galaxy spectra. Rather than an alternative to existing automated tools, it is put forward as an instrument for quick-look analysis and for gaining physical insight when interpreting the outputs provided by automated tools. Though the recipe is for general application, it was developed for understanding the nature of the Automatic Spectroscopic K-means-based (ASK) template spectra. They resulted from the classification of all the galaxy spectra in the Sloan Digital Sky Survey data release 7, thus being a comprehensive representation of the galaxy spectra in the local universe. Using the recipe, we give a description of the properties of the gas and the stars that characterize the ASK classes, from those corresponding to passively evolving galaxies, to H II galaxies undergoing a galaxy-wide starburst. The qualitative analysis is found to be in excellent agreement with quantitative analyses of the same spectra. We compare the mean ages of the stellar populations with those inferred using the code STARLIGHT. We also examine the estimated gas-phase metallicity with the metallicities obtained using electron-temperature-based methods. A number of byproducts follow from the analysis. There is a tight correlation between the age of the stellar population and the metallicity of the gas, which is stronger than the correlations between galaxy mass and stellar age, and galaxy mass and gas metallicity. The galaxy spectra are known to follow a one-dimensional sequence, and we identify the luminosity-weighted mean stellar age as the affine parameter that describes the sequence. All ASK classes happen to have a significant fraction of old stars, although spectrum-wise they are outshined by the youngest populations. Old stars are metal-rich or metal-poor depending on whether they reside in passive galaxies or in star-forming galaxies.

  14. MEASUREMENT OF THE HIGH ENERGY COMPONENT OF THE X-RAY SPECTRA INTHE VENUS ECR ION SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Daniela; Benitez, Janilee Y.; Lyneis, Claude M.; Todd,Damon S.; Ropponen,Tommi; Ropponen,Janne; Koivisto, Hannu; Gammino, Santo

    2007-11-15

    High performance electron cyclotron resonance (ECR) ion sources, such as VENUS (Versatile ECR for Nuclear Science), produce large amounts of x-rays. By studying their energy spectra, conclusions can be drawn about the electron heating process and the electron confinement. In addition, the bremsstrahlung from the plasma chamber is partly absorbed by the cold mass of the superconducting magnet adding an extra heat load to the cryostat. Germanium or NaI detectors are generally used for x-ray measurements. Due to the high x-ray flux from the source, the experimental set-up to measure bremsstrahlung spectra from ECR ion sources is somewhat different than for the traditional nuclear physics measurements these detectors are generally used for. In particular the collimation and background shielding can be problematic. In this paper we will discuss the experimental set-up for such a measurement, the energy calibration and background reduction, the correction for detector efficiency, the shielding of the detector and collimation of the x-ray flux. We will present x-ray energy spectra and cryostat heating rates in dependence of various ion source parameters such as confinement fields, minimum B-field, rf power and heating frequency.

  15. Co-firing Bosnian coals with woody biomass: Experimental studies on a laboratory-scale furnace and 110 MWe power unit

    Directory of Open Access Journals (Sweden)

    Smajevic Izet

    2012-01-01

    Full Text Available This paper presents the findings of research into cofiring two Bosnian cola types, brown coal and lignite, with woody biomass, in this case spruce sawdust. The aim of the research was to find the optimal blend of coal and sawdust that may be substituted for 100% coal in large coal-fired power stations in Bosnia and Herzegovina. Two groups of experimental tests were performed in this study: laboratory testing of co-firing and trial runs on a large-scale plant based on the laboratory research results. A laboratory experiment was carried out in an electrically heated and entrained pulverized-fuel flow furnace. Coal-sawdust blends of 93:7% by weight and 80:20% by weight were tested. Co-firing trials were conducted over a range of the following process variables: process temperature, excess air ratio and air distribution. Neither of the two coal-sawdust blends used produced any significant ash-related problems provided the blend volume was 7% by weight sawdust and the process temperature did not exceed 1250ºC. It was observed that in addition to the nitrogen content in the co-fired blend, the volatile content and particle size distribution of the mixture also influenced the level of NOx emissions. The brown coal-sawdust blend generated a further reduction of SO2 due to the higher sulphur capture rate than for coal alone. Based on and following the laboratory research findings, a trial run was carried out in a large-scale utility - the Kakanj power station, Unit 5 (110 MWe, using two mixtures; one in which 5%/wt and one in which 7%/wt of brown coal was replaced with sawdust. Compared to a reference firing process with 100% coal, these co-firing trials produced a more intensive redistribution of the alkaline components in the slag in the melting chamber, with a consequential beneficial effect on the deposition of ash on the superheater surfaces of the boiler. The outcome of the tests confirms the feasibility of using 7%wt of sawdust in combination

  16. Characterizing Sky Spectra Using SDSS BOSS Data

    Science.gov (United States)

    Florez, Lina Maria; Strauss, Michael A.

    2018-01-01

    In the optical/near-infrared spectra gathered by a ground-based telescope observing very faint sources, the strengths of the emission lines due to the Earth’s atmosphere can be many times larger than the fluxes of the sources we are interested in. Thus the limiting factor in faint-object spectroscopy is the degree to which systematics in the sky subtraction can be minimized. Longwards of 6000 Angstroms, the night-sky spectrum is dominated by multiple vibrational/rotational transitions of the OH radical from our upper atmosphere. While the wavelengths of these lines are the same in each sky spectrum, their relative strengths vary considerably as a function of time and position on the sky. The better we can model their strengths, the better we can hope to subtract them off. We expect that the strength of lines from common upper energy levels will be correlated with one another. We used flux-calibrated sky spectra from the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (SDSS BOSS) to explore these correlations. Our aim is to use these correlations for creating improved sky subtraction algorithms for the Prime Focus Spectrograph (PFS) on the 8.2-meter Subaru Telescope. When PFS starts gathering data in 2019, it will be the most powerful multi-object spectrograph in the world. Since PFS will be gathering data on sources as faint as 24th magnitude and fainter, it's of upmost importance to be able to accurately measure and subtract sky spectra from the data that we receive.

  17. LSD-based analysis of high-resolution stellar spectra

    Science.gov (United States)

    Tsymbal, V.; Tkachenko, A.; Van, Reeth T.

    2014-11-01

    We present a generalization of the method of least-squares deconvolution (LSD), a powerful tool for extracting high S/N average line profiles from stellar spectra. The generalization of the method is effected by extending it towards the multiprofile LSD and by introducing the possibility to correct the line strengths from the initial mask. We illustrate the new approach by two examples: (a) the detection of astroseismic signatures from low S/N spectra of single stars, and (b) disentangling spectra of multiple stellar objects. The analysis is applied to spectra obtained with 2-m class telescopes in the course of spectroscopic ground-based support for space missions such as CoRoT and Kepler. Usually, rather high S/N is required, so smaller telescopes can only compete successfully with more advanced ones when one can apply a technique that enables a remarkable increase in the S/N of the spectra which they observe. Since the LSD profiles have a potential for reconstruction what is common in all the spectral profiles, it should have a particular practical application to faint stars observed with 2-m class telescopes and whose spectra show remarkable LPVs.

  18. Fluorescence Spectra of Highlighter Inks

    Science.gov (United States)

    Birriel, Jennifer J.; King, Damon

    2018-01-01

    Fluorescence spectra excited by laser pointers have been the subject of several papers in "TPT". These papers all describe a fluorescence phenomenon in which the reflected laser light undergoes a change in color: this color change results from the combination of some partially reflected laser light and additional colors generated by…

  19. INFRARED SPECTRA, THERMOGRAVIMETRIC ANALYSIS AND ...

    African Journals Online (AJOL)

    Preferred Customer

    characterized by melting point, molar conductivity, magnetic moment, elemental analysis, infrared spectra and thermal analyses. ... methyl-quinazolinone and the final products of the thermogravimetric analysis were recorded on a Perkin-Elmer FT-IR type ..... [Cu(CH3COO)(L)3]. CuO + 5C +12C2H2 + 4NO + NH3 + 0.5N2.

  20. COMPARISON OF CALCULATED AND OBSERVED SEISMIC ACCELERATIONS IN COMPOSITE-TYPE ROCK-FILL DAM OF THE DNESTROVSKAYA HYDRO-ELECTRIC POWER PLANT DURING EXPERIMENTAL EXPLOSIONS

    Directory of Open Access Journals (Sweden)

    A. A. Matvienko

    2016-01-01

    Full Text Available A methodology for determination of seismic accelerations in earth dams has been developed within the framework of seismic resistance wave theory. In this case we take into account an influence of the dam foundation and seismic wave emission into it. The methodology is based on numerical solution of the dynamic problem while using a finite difference method. A software program SGD “Determination of seismic acceleration in the earth dam” has been prepared on the basis of the developed methodology. The program allows to evaluate ordinates of calculation orthographic representations for acceleration throughout the dam height for all time moments. Thus, it is possible to obtain the most dangerous acceleration orthographic representations at direct and reverse seismic actions. The papers presents verification (compliance test of calculated and observed seismic accelerations for the rock-fill dam of the Dnestrovskaya Hydro-Electric Power Plant No 1. The observed seismic accelerations have been obtained during experimental explosions. The calculated seismic accelerations have been obtained in accordance with the proposed methodology for determination of seismic accelerations in the earth dams. A comparative analysis of calculation results with the data of field observations has demonstrated that a maximum difference between extreme accelerations obtained by calculation, and during field observations, do not exceed 10.11 % for the dam crest, and 6.56 % for its bottom. The obtained results permit to recommend the developed program for engineering calculations of seismic accelerations in the earth dams. The program application will make it possible to determine seismic acceleration in the earth dam with sufficient reliability.